Optimal Control and Dynamic Games-- Applications in Finance ...S---优化问题
Optimal Control and Estimation
Optimal Control and Estimation Optimal control and estimation are crucial concepts in the field ofengineering and mathematics, playing a significant role in various real-world applications such as robotics, aerospace, economics, and more. These concepts are essential for designing systems that can achieve the best performance while considering constraints and uncertainties. In this discussion, we will explore the importance of optimal control and estimation from multiple perspectives, considering their practical applications, theoretical foundations, and the challenges involved in implementing these techniques. From a practical standpoint, optimal control and estimation are essential for designing and controlling complex systems such as autonomous vehicles, industrial processes, and aerospace systems. For instance, in the context of autonomous vehicles, optimal control techniquesare used to plan the vehicle's trajectory while considering factors such astraffic conditions, safety constraints, and energy efficiency. Similarly, estimation techniques such as Kalman filtering are used for state estimation, allowing the vehicle to accurately perceive its environment and make informed decisions. These applications highlight the critical role of optimal control and estimation in enabling advanced technologies that have the potential to transform various industries. On a theoretical level, optimal control and estimation are grounded in mathematical optimization and statistical inference, drawing from disciplines such as control theory, optimization, and probability theory. Optimal control problems often involve finding the control inputs that minimize a certain cost function while satisfying system dynamics and constraints. This requires a deep understanding of optimization algorithms, dynamic programming, andPontryagin's maximum principle. On the other hand, estimation methods such as the Kalman filter and particle filters are rooted in Bayesian inference, involving the recursive update of probability distributions based on noisy measurements and system dynamics. The theoretical foundations of optimal control and estimation provide the necessary framework for developing and analyzing algorithms that can handle real-world complexities. However, the implementation of optimal controland estimation techniques is not without challenges. One of the primary challenges is the need for accurate models of the system dynamics and sensor measurements. Inmany real-world applications, the underlying dynamics may be complex and uncertain, leading to difficulties in formulating precise models for control and estimation. Additionally, the computational complexity of optimal control and estimation algorithms can be prohibitive, especially for real-time applications. Balancingthe trade-off between computational efficiency and optimality is a non-trivial task, requiring careful algorithm design and implementation. Moreover, the integration of optimal control and estimation techniques with modern technologies such as machine learning and deep learning presents both opportunities and challenges. While machine learning methods can potentially enhance the accuracy of system models and sensor data processing, integrating these techniques with traditional optimal control and estimation frameworks requires a deep understanding of both domains. Furthermore, ensuring the safety and reliability of autonomous systems that rely on optimal control and estimation poses ethical and societal challenges, especially in high-stakes domains such as healthcare and transportation. In conclusion, optimal control and estimation are fundamental concepts with far-reaching implications across various domains. From enabling the autonomy of vehicles to optimizing industrial processes, these techniques are essential for achieving superior performance in the presence of uncertainties and constraints. However, the practical implementation of optimal control and estimation poses significant challenges, ranging from modeling complexities to computational considerations. Addressing these challenges requires a multidisciplinary approach, combining expertise in control theory, optimization, statistics, and emerging technologies. As we continue to advance in the era of autonomous systems and smart technologies, the role of optimal control and estimation will only become more pronounced, shaping the future of engineering and beyond.。
不同效用函数下的最优投资组合策略
不同效用函数下的最优投资组合策略张夏洁;刘宣会;贾丹琴【摘要】当股价受到重大信息冲击时,会出现不连续的跳跃,将股价考虑为服从跳跃-扩散过程。
为了研究当股价服从跳跃-扩散过程时,不同效用函数下投资者投资组合的最优策略问题,基于随机微分对策思想,在股票价格服从跳跃-扩散过程时,通过建立投资组合的数学模型,根据 Ito 公式和泛函变分法,分别采用对数效用函数和幂效用函数研究两人竞争的投资组合优化问题,并得到在各自效用函数下最优策略的表达式,为投资者提供多种投资策略。
%When the stock is impacted by the significant information,the share price will be dis-continuous jumps,generally considered following jump-diffusion process.When stock price follows the jump diffusion process,in order to study the optimal strategy of the investors′port-folio under different utility functions,based on the stochastic differential game,the optimal portfolio strategy problem of the two person competition was studied respectively,under the logarithmic utility function and the power utility function by building the mathematical model of the investment portfolio,and using the Ito formula and functional variational method.Then the optimal portfolio strategy expression was obtained respectively under the different utility functions to provide investors with a variety of alternative investment strategies.【期刊名称】《纺织高校基础科学学报》【年(卷),期】2016(029)001【总页数】8页(P39-46)【关键词】随机微分对策;跳跃-扩散过程;对数效用函数;幂效用函数;Ito 公式;最优投资组合策略【作者】张夏洁;刘宣会;贾丹琴【作者单位】西安工程大学理学院,陕西西安 710048;西安工程大学理学院,陕西西安 710048;西安工程大学理学院,陕西西安 710048【正文语种】中文【中图分类】O211.63投资组合理论的核心思想是选择投资组合,达到风险分散化,追求收益最大化和风险最小化.投资者通过组合投资在投资收益和投资风险中找寻平衡点,即在风险一定的条件下实现收益的最大化或在收益一定的条件下使风险尽可能地降低.该理论最早是由美国著名经济学家Markowitz[1]于1952年提出的,他在利用均值-方差进行投资组合选择的问题上,首次将风险数量化,此后大量有关投资组合的问题开始得到深入研究[2-5].随着金融学和随机学等近代数学理论的发展,最优投资组合策略问题已成为金融数学中的热门问题之一.其中,博弈论成为研究最优投资组合问题的主要理论之一[6-8].Browne[9]研究了股价服从几何布朗运动时两人零和随机微分对策问题,但是当受到重大信息(如经济危机,政治事件等)冲击时,股价会出现不连续的跳跃[10-12].一般的布朗运动已然无法满足实际市场股票价格变化的需求,因此研究股价服从跳跃-扩散过程对金融市场的需求具有重要意义.本文将Browne的模型进行推广,当股价服从跳跃-扩散过程时,基于随机微分对策思想,运用Ito公式和泛函变分法,分别研究在对数效用函数和幂效用函数下的两人投资竞争的最优投资组合策略问题.定义1[13] 设ft,gt(t∈[0,T])均为Ft适应过程,且满足,则称ft,gt为可容许策略.引理1[14] (Ito公式)设跳扩散过程其中W(t)为标准布朗运动,N(t)是强度为λ的Poisson过程,W(t)、N(t)彼此相互独立,函数f(t,xt)关于t是一阶可导,关于x是连续可导,那么有定义2[15] (效用函数)非减上凸函数U:R→(-∞,+∞)称为效用函数,若满足(1) U′(x)存在且连续;(2) U′(x)为正的,且严格递减;(3) U′(+∞)≜常见的效用函数有U(x)=lnx(x>0)(对数函数),U(x)<1且p≠0)(幂函数),U(x)=1-exp(-px)(p>0)(指数函数)等.其中,p被称为风险厌恶指数.定义3[9] (最优策略)在有限时间段[0,T]内,投资者甲寻求策略ft,使得期望效用最大.同时投资者乙寻求策略gt,使得期望效用最小.令则满足的ft,gt为投资者的最优策略.其中分别表示投资者甲,乙可容许策略所组成的集合.定义4 设J(y)为泛函,y为规定的域内可以取得的曲线(简称可取曲线),为极值曲线,若,则称泛函有极大值;若,则称泛函有极小值.引理2[16] 如果设(y在可取域内变化,F为x,y(x)的函数),极值曲线为(x),可取曲线为y=y(x),令π(x),则为极值的充要条件为δJ=0⟺Fy=0.当δ2J>0时,取得极小值;δ2J<0时,取得极大值.当有重大信息出现时(如经济危机,政治事件等),股价受到冲击,出现不连续的跳跃,这时将股票价格考虑为跳跃-扩散模型.假设金融市场上仅有3种证券,一种是无风险资产,称为债券p0,另2种是风险资产,称为股票S(1)和S(2),其价格分别满足其中,μi>r,i=1,2,μi,σi,φi均为常数,Wt为一维标准布朗运动,Nt是参数为λ的Poisson过程.设定投资者甲,乙均可在无风险资产(即债券)上投资.另外,投资者甲仅限于在股票S(1)上投资,投资者乙仅限于在股票S(2)上投资.设Xt表示甲t时刻的投资财富过程,Yt表示乙t时刻的投资财富过程.ft表示投资者甲t时刻在股票S(1)上投资的财富比例;gt表示投资者乙t时刻在股票S(2)上投资的财富比例.设表示t时刻投资者甲的财富,并有X0=x,因为投资者甲的财富不是投资在股票S(1)上,便会投资在债券上,那么甲的财富过程为同理,表示时刻t时投资者乙的财富,且有Y0=y,那么投资者乙的财富过程为如果令表示投资者甲、乙在t时刻的财富比值,可以得到的具体表达式,即其中,mi,ni分别表示在[0,T]时间内第1种与第2种股票价格在第i次发生跳跃的时间.NT表示在[0,T]时间内股票价格发生跳跃的次数,并假设2种股票均为NT.证明对式(2)和(3)分别应用Ito公式得其中则3.1 对数函数效用下的最优投资组合策略令U(x)=lnx(x>0),则,有如下定理.定理1 如果满足,则投资者甲、乙的最优投资策略分别是其中[0,T].证明由于所以又因为在和式中,mi表示过程Nt中股票S(1)价格发生跳跃的时间,由Poisson的特性可知m1…mn是Poisson过程Nt中的点所发生的时间的一个随机排列,而有限和式的值与次序无关,所以它们是相互独立同分布的随机变量.且其密度函数为fm(x)=λ/T,(0≤x≤T),则所以同理可得则这时分别为因而,要使(z),只需求解式(6)和(7)就能得到最优投资策略.根据引理2有解之可得其中由于因而式(6)的最优解为即在确定性对数效用函数下,投资者甲的最优投资组合策略为:在股票S(1)上投资的财富比例为,在债券P0上投资的比例为同理可得式(7)的最优解为其中).即在确定性对数效用函数下,投资者乙的最优投资组合策略为:在股票S(2)上投资的财富比例为,在债券p0上投资的比例为3.2 幂函数效用下的最优投资组合策略令,其中p为常数,且满足0<p<1,p≠0,则幂效用函数有常系数的相对风险厌恶指数1-p.此时,).再令则根据exp(x)的泰勒展开式有exp(x),所以).定理2 如果满足且,则投资者甲、乙的最优投资策略分别是:满足方程组的隐式解ft,即和满足方程组的隐式解gt,即证明令则由于,所以故此时分别为要使(z),只需求解(9)和(10)就能得到最优投资策略.根据引理2有由于,所以故式(9)的最优解存在且唯一,且满足以下方程组的隐式解:即在确定性幂效用函数下,投资者甲的最优投资组合策略为:在股票S(1)上投资的财富比例为,在债券p0上投资的比例为同理可得式(10)的最优解为满足以下方程组的隐式解:即在确定性幂效用函数下,投资者乙的最优投资组合策略为:在股票S(2)上投资的财富比例为,在债券p0上投资的比例为将Browne的模型进行推广,考虑到当股价受到重大信息冲击时,会出现不连续的跳跃,研究股价服从跳跃-扩散过程时的最优策略对实际金融市场具有重要意义.在股价服从跳跃-扩散过程时,基于随机微分对策思想,分别选用对数效用函数和幂效用函数来研究两人竞争的投资组合优化策略问题,投资者甲选择投资策略期望效用最大化,投资者乙选择同一期望效用最小化,运用Ito公式和泛函变分法,分别得到各自投资组合最优策略.由此可知,投资者选用不同的效用函数得到的最优策略也不同,这也将影响投资者的决策.文中仅是对幂效用函数以及对数效用函数下股价服从跳-扩过程的最优策略进行了研究,对指数效用函数下两人竞争投资组合最优策略问题还需作进一步的研究.ZHANG Xiajie,LIU Xuanhui,JIA Danqin.The optimal portfolio strategy underdifferent utility functions[J].Basic Sciences Journal of Textile Universities,2016,29(1):39-46.【相关文献】[1] MARKOWITZ H. Portfolio selection[J]. Journal of Finance,1952, 7(1):77-91.[2] FU C,LARI-Lavassani A,LI X. Dynamic mean-variance portfolio selection with borrowing constraint[J].European Journal of Operation Research, 2010,200(1):312-319.[3] 王业萍,罗成新.利率受随机因子影响的投资组合问题[J].沈阳师范大学学报:自然科学版,2010,28(2):141-143.WANG Yeping,LUO Chengxin.Portfolio problem about the interest rates affected by stochatic factor[J].Journal of Shenyang Normal University:Natural Science,2010,28(2):141-143.[4] 王秀国,王义东.基于随机基准的动态均值-方差投资组合选择[J].控制与决策,2014,29(3):499-505.WANG Xiuguo,WANG Yidong.Dynamic mean-variance portfolio selection based on stochastic benchmark[J].Control and Decision,2014,29(3):499-505.[5] 荣幸.组合投资选择的随机最优控制方法[J].工程数学学报,2014,31(2):159-165.RONG Xing.Stochastic optimal control method for portfolio selection[J].Chinese Journal of Engineering Mathematics,2014,31(2):159-165.[6] 刘海龙,樊志平,潘德惠,等.基于微分对策的证券投资决策方法[J].东北大学学报:自然科学版,1999,20(1):101-104.LIU Hailong,FAN Zhiping,PAN Dehui,et al.Security investment decision method based on differential game[J].Journal of Northeastern University:Natural ScienceEdition,1999,20(1):101-104.[7] 田颖.随机微分对策的最优目标问题[D].山东:山东大学,2011:1-6.TIAN Ying.The optimal objective problem of stochastic differentialgames[D].Shandong:Shandong University,2011:1-6.[8] 黄俏玲,林祥.零和随机微分投资组合博弈问题[D].长沙:中南大学,2013:40-46.HUANG Qiaoling,LIN Xiang.Zero-sum stochastic differential portfoliogames[D].Changsha:Central South University,2013:40-46.[9] BROWEN Sid.Stochastic differential portfolio games[J]. Journal of Applied Probability,1998,37(1):126-147.[10] 刘宣会,徐成贤.基于跳跃-扩散过程的一类亚式期权定价[J].系统工程学报,2008,23(2):142-147. LIU Xuanhui,XU option pricing based on jump-diffusion priceprocess[J].Journal of Systems Engineering,2008,23(2):142-147.[11] 薛赟,刘宣会.带跳的具有卖空限制的证券投资组合选择问题[J].纺织高校基础科学学报,2010,23(1):46-53.XUE Zan,LIU Xuanhui.Mean-variance portfolio selection with no-shorting constraints when stock prices follow jump-diffusion process[J].Basic Sciences Journal of Textile Universities,2010,23(1):46-53.[12] 张柯妮.基于随机LQ控制的一类投资组合优化策略[J].纺织高校基础科学学报,2012,25(3):246-250.ZHANG Keni.A kind of optimal portfolio selection problem based on stochastic LQcontrol[J].Basic Sciences Journal of Textile Universities,2012,25(3):246-250.[13] 张波,商豪.应用随机过程[M].第二版.北京:中国人民大学出版社,2009:50-51.ZHANG Bo,SHANG Hao.Stochastic process[M].2nd edition.Beijing:China Renmin University Press,2009:50-51.[14] APPLEBAUM D.Lévy processes and stochastic calculus[M]. Cambridge:Cambridge University Press,2004:214-219.[15] 金治明.数学金融学基础[M].北京:科学出版社,2006:305-322.JIN Zhiming.Mathematical finance basis[M].Beijing:Science Press,2006:305-322.[16] 张景肖.随机最优控制及其在保险中的应用[M].北京:科学出版社,2013.ZHANG Jingxiao.Stochastic optimal control and application ininsurance[M].Beijing:Science Press,2013.。
Advanced Control Theory and Applications
Advanced Control Theory and Applications Advanced control theory and its applications play a crucial role in various engineering fields, including aerospace, robotics, automotive systems, and industrial automation. This field encompasses a wide range of complex theories, mathematical models, and practical applications that are essential for the development of advanced control systems. In this article, we will explore the significance of advanced control theory and its diverse applications, considering multiple perspectives and addressing the emotional and practical aspects of this dynamic field. From a theoretical standpoint, advanced control theory delves into intricate mathematical concepts, such as state-space representation, optimal control, adaptive control, and robust control. These theories provide engineers with powerful tools to analyze and design control systems that can effectively regulate complex dynamical systems. The ability to mathematically model and analyze the behavior of such systems is fundamental for ensuring stability, performance, and robustness in real-world applications. Moreover, the theoretical foundation of advanced control theory forms the basis for innovative research in control system design, paving the way for technological advancements and breakthroughs in various industries. In the realm of practical applications, advanced control theory finds extensive utilization in diverse engineering disciplines. For instance, in the field of aerospace engineering, advanced control systems are indispensable for stabilizing aircraft, spacecraft, and missiles, enabling precise maneuvering and navigation. The integration of advanced control algorithms, such as model predictive control and adaptive control, enhances the safety and performance of aerospace vehicles, addressing critical challenges in dynamic and uncertain environments. Similarly, in the automotive industry, advanced control theory contributes to the development of autonomous vehicles, electric powertrains, and active safety systems, revolutionizing the future of transportation. Beyond the technical aspects, the impact of advanced control theory resonates on a human level, influencing safety, efficiency, and innovation in everyday life. Consider the role of advanced control systems in medical devices and healthcare technology, where precise control algorithms are vital for patient monitoring, drug delivery, and surgical robotics. The application of advancedcontrol theory in medical settings directly translates to improved patient outcomes, reduced human error, and enhanced quality of care. This human-centric perspective underscores the profound significance of advanced control theory in shaping the advancements that directly impact and improve human lives. Furthermore, the interdisciplinary nature of advanced control theory fosters collaboration and knowledge exchange across various fields, transcendingtraditional boundaries and inspiring creative solutions to complex problems. The fusion of control theory with artificial intelligence, machine learning, andcyber-physical systems exemplifies the synergy of diverse disciplines, leading to the development of intelligent control systems with adaptive, learning capabilities. This convergence of technologies not only amplifies thefunctionality of control systems but also opens new frontiers for innovation, offering unprecedented opportunities for addressing global challenges. In conclusion, the realm of advanced control theory and its applications encompasses a rich tapestry of theoretical foundations, practical implementations, and human-centric impacts. From enabling the stability and precision of aerospace systems to enhancing the safety and efficiency of autonomous vehicles, advanced control theory permeates diverse facets of modern engineering. Its significance extends beyond technical prowess, influencing the very fabric of human progress, innovation, and well-being. As we continue to push the boundaries of technological advancement, the profound influence of advanced control theory will undoubtedly shape the future of engineering and society as a whole.。
不对称约束多人非零和博弈的自适应评判控制
第40卷第9期2023年9月控制理论与应用Control Theory&ApplicationsV ol.40No.9Sep.2023不对称约束多人非零和博弈的自适应评判控制李梦花,王鼎,乔俊飞†(北京工业大学信息学部,北京100124;计算智能与智能系统北京市重点实验室,北京100124;智慧环保北京实验室,北京100124;北京人工智能研究院,北京100124)摘要:本文针对连续时间非线性系统的不对称约束多人非零和博弈问题,建立了一种基于神经网络的自适应评判控制方法.首先,本文提出了一种新颖的非二次型函数来处理不对称约束问题,并且推导出最优控制律和耦合Hamilton-Jacobi方程.值得注意的是,当系统状态为零时,最优控制策略是不为零的,这与以往不同.然后,通过构建单一评判网络来近似每个玩家的最优代价函数,从而获得相关的近似最优控制策略.同时,在评判学习期间发展了一种新的权值更新规则.此外,通过利用Lyapunov理论证明了评判网络权值近似误差和闭环系统状态的稳定性.最后,仿真结果验证了本文所提方法的有效性.关键词:神经网络;自适应评判控制;自适应动态规划;非线性系统;不对称约束;多人非零和博弈引用格式:李梦花,王鼎,乔俊飞.不对称约束多人非零和博弈的自适应评判控制.控制理论与应用,2023,40(9): 1562–1568DOI:10.7641/CTA.2022.20063Adaptive critic control for multi-player non-zero-sum games withasymmetric constraintsLI Meng-hua,WANG Ding,QIAO Jun-fei†(Faculty of Information Technology,Beijing University of Technology,Beijing100124,China;Beijing Key Laboratory of Computational Intelligence and Intelligent System,Beijing100124,China;Beijing Laboratory of Smart Environmental Protection,Beijing100124,China;Beijing Institute of Artificial Intelligence,Beijing100124,China)Abstract:In this paper,an adaptive critic control method based on the neural networks is established for multi-player non-zero-sum games with asymmetric constraints of continuous-time nonlinear systems.First,a novel nonquadratic func-tion is proposed to deal with asymmetric constraints,and then the optimal control laws and the coupled Hamilton-Jacobi equations are derived.It is worth noting that the optimal control strategies do not stay at zero when the system state is zero, which is different from the past.After that,only a critic network is constructed to approximate the optimal cost function for each player,so as to obtain the associated approximate optimal control strategies.Meanwhile,a new weight updating rule is developed during critic learning.In addition,the stability of the weight estimation errors of critic networks and the closed-loop system state is proved by utilizing the Lyapunov method.Finally,simulation results verify the effectiveness of the method proposed in this paper.Key words:neural networks;adaptive critic control;adaptive dynamic programming;nonlinear systems;asymmetric constraints;multi-player non-zero-sum gamesCitation:LI Menghua,WANG Ding,QIAO Junfei.Adaptive critic control for multi-player non-zero-sum games with asymmetric constraints.Control Theory&Applications,2023,40(9):1562–15681引言自适应动态规划(adaptive dynamic programming, ADP)方法由Werbos[1]首先提出,该方法结合了动态规划、神经网络和强化学习,其核心思想是利用函数近似结构来估计最优代价函数,从而获得被控系统的近似最优解.在ADP方法体系中,动态规划蕴含最优收稿日期:2022−01−21;录用日期:2022−11−10.†通信作者.E-mail:***************.cn.本文责任编委:王龙.科技创新2030–“新一代人工智能”重大项目(2021ZD0112302,2021ZD0112301),国家重点研发计划项目(2018YFC1900800–5),北京市自然科学基金项目(JQ19013),国家自然科学基金项目(62222301,61890930–5,62021003)资助.Supported by the National Key Research and Development Program of China(2021ZD0112302,2021ZD0112301,2018YFC1900800–5),the Beijing Natural Science Foundation(JQ19013)and the National Natural Science Foundation of China(62222301,61890930–5,62021003).第9期李梦花等:不对称约束多人非零和博弈的自适应评判控制1563性原理提供理论基础,神经网络作为函数近似结构提供实现手段,强化学习提供学习机制.值得注意的是, ADP方法具有强大的自学习能力,在处理非线性复杂系统的最优控制问题上具有很大的潜力[2–7].此外, ADP作为一种近似求解最优控制问题的新方法,已经成为智能控制与计算智能领域的研究热点.关于ADP的详细理论研究以及相关应用,读者可以参考文献[8–9].本文将基于ADP的动态系统优化控制统称为自适应评判控制.近年来,微分博弈问题在控制领域受到了越来越多的关注.微分博弈为研究多玩家系统的协作、竞争与控制提供了一个标准的数学框架,包括二人零和博弈、多人零和博弈以及多人非零和博弈等.在零和博弈问题中,控制输入试图最小化代价函数而干扰输入试图最大化代价函数.在非零和博弈问题中,每个玩家都独立地选择一个最优控制策略来最小化自己的代价函数.值得注意的是,零和博弈问题已经被广泛研究.在文献[10]中,作者提出了一种改进的ADP方法来求解多输入非线性连续系统的二人零和博弈问题.An等人[11]提出了两种基于积分强化学习的算法来求解连续时间系统的多人零和博弈问题.Ren等人[12]提出了一种新颖的同步脱策方法来处理多人零和博弈问题.然而,关于非零和博弈[13–14]的研究还很少.此外,控制约束在实际应用中也广泛存在.这些约束通常是由执行器的固有物理特性引起的,如气压、电压和温度.因此,为了确保被控系统的性能,受约束的系统需要被考虑.Zhang等人[15]发展了一种新颖的事件采样ADP方法来求解非线性连续约束系统的鲁棒最优控制问题.Huo等人[16]研究了一类非线性约束互联系统的分散事件触发控制问题.Yang和He[17]研究了一类具有不匹配扰动和输入约束的非线性系统事件触发鲁棒镇定问题.这些文献考虑的都是对称约束,而实际应用中,被控系统受到的约束也可能是不对称的[18–20],例如在污水处理过程中,需要通过氧传递系数和内回流量对溶解氧浓度和硝态氮浓度进行控制,而根据实际的运行条件,这两个控制变量就需要被限制在一个不对称约束范围内[20].因此,在控制器设计过程中,不对称约束问题将是笔者研究的一个方向.到目前为止,关于具有控制约束的微分博弈问题,有一些学者取得了相应的研究成果[12,21–23].但可以发现,具有不对称约束的多人非零和博弈问题还没有学者研究.同时,在多人非零和博弈问题中,相关的耦合Hamilton-Jacobi(HJ)方程是很难求解的.因此,本文针对一类连续时间非线性系统的不对称约束多人非零和博弈问题,提出了一种自适应评判控制方法来近似求解耦合HJ方程,从而获得被控系统的近似最优解.本文的主要贡献如下:1)首次将不对称约束应用到连续时间非线性系统的多人非零和博弈问题中;2)提出了一种新颖的非二次型函数来处理不对称约束问题,并且当系统状态为零时,最优控制策略是不为零的,这与以往不同;3)在学习期间,用单一评判网络结构代替了传统的执行–评判网络结构,并且提出了一种新的权值更新规则;4)利用Lyapunov方法证明了评判网络权值近似误差和系统状态的一致最终有界(uniformly ultimately bounded,UUB)稳定性.2问题描述考虑以下具有不对称约束的N–玩家连续时间非线性系统:˙x(t)=f(x(t))+N∑j=1g j(x(t))u j(t),(1)其中:x(t)∈Ω⊂R n是状态向量且x(0)=x0为初始状态,R n代表由所有n-维实向量组成的欧氏空间,Ω是R n的一个紧集;u j(t)∈T j⊂R m为玩家j在时刻t所选择的策略,且T j为T j={[u j1u j2···u jm]T∈R m:u j min u jl u j max, |u j min|=|u j max|,l=1,2,···,m},(2)其中:u jmin∈R和u j max∈R分别代表控制输入分量的最小界和最大界,R表示所有实数集.假设1非线性系统(1)是可控的,并且x=0是被控系统(1)的一个平衡点.此外,∀j∈N,f(x)和g j(x)是未知的Lipschitz函数且f(0)=0,其中集合N={1,2,···,N},N 2是一个正整数.假设2∀j∈N,g j(0)=0,且存在一个正常数b gj使∥g j(x)∥ b gj,其中∥·∥表示在R n上的向量范数或者在R n×m上的矩阵范数,R n×m代表由所有n×m维实矩阵组成的空间.注1假设1–3是自适应评判领域的常用假设,例如文献[6,13,19],是为了保证系统的稳定性以及方便后文中的稳定性证明,其中假设3出现在后文中的第3.2节.定义与每个玩家相关的效用函数为U i(x,U)=x T Q i x+N∑j=1S j(u j),i∈N,(3)其中U={u1,u2,···,u N}并且Q i是一个对称正定矩阵.此外,为了处理不对称约束问题,令S j(u j)为S j(u j)=2αj m∑l=1ujlβjtanh−1(z−βjαj)d z,(4)其中αj和βj分别为αj=u jmax−u j min2,βj=u jmax+u jmin2.(5)因此,与每个玩家相关的代价函数可以表示为J i(x0,U)=∞U i(x,U)dτ,i∈N,(6)1564控制理论与应用第40卷本文希望构建一个Nash均衡U∗={u∗1,u∗2,···,u∗N},来使以下不等式被满足:J i(u∗1,···,u∗i,···,u∗N)J i(u∗1,···,u i,···,u∗N),(7)其中i∈N.为了方便,将J i(x0,U)简写为J i(x0).于是,每个玩家的最优代价函数为J∗i (x0)=minu iJ i(x0,U),i∈N.(8)在本文中,如果一个控制策略集的所有元素都是可容许的,那么这个集合是可容许的.定义1(容许控制[24])如果控制策略u i(x)是连续的,u i(x)可以镇定系统(1),并且J i(x0)是有限的,那么它是集合Ω上关于代价函数(6)的可容许控制律,即u i(x)∈Ψ(Ω),i∈N,其中,Ψ(Ω)是Ω上所有容许控制律的集合.对于任意一个可容许控制律u i(x)∈Ψ(Ω),如果相关代价函数(6)是连续可微的,那么非线性Lyapu-nov方程为0=U i(x,U)+(∇J i(x))T(f(x)+N∑j=1g j(x)u j),(9)其中:i∈N,J i(0)=0,并且∇(·) ∂(·)∂x.根据最优控制理论,耦合HJ方程为0=minU H i(x,U,∇J∗i(x)),i∈N,(10)其中,Hamiltonian函数H i(x,U,∇J∗i(x))为H i(x,U,∇J∗i(x))=U i(x,U)+(∇J∗i (x))T(f(x)+N∑j=1g j(x)u j),(11)进而,由∂H i(x,U,∇J∗i(x))∂u i=0可得出最优控制律为u∗i (x)=−αi tanh(12αig Ti(x)∇J∗i(x))+¯βi,i∈N,(12)其中¯βi=[βiβi···βi]T∈R m.注2根据式(2)和式(5),能推导出βi=0,即¯βi=0,又根据式(12)可知u∗i(0)=0,i∈N.因此,为了保证x=0是系统(1)的平衡点,在假设2中提出了条件∀j∈N,g j(0)=0.将式(12)代入式(10),耦合HJ方程又能表示为(∇J∗i (x))T f(x)+N∑j=1((∇J∗i(x))T g j(x)¯βj)+x T Q i x−N∑j=1((∇J∗i(x))Tαj g j(x)tanh(A j(x)))+N∑j=1S j(−αj tanh(A j(x))+¯βj)=0,i∈N,(13)其中J∗i(0)=0并且A j(x)=12αjg Tj(x)∇J∗j(x).如果已知每个玩家的最优代价函数值,那么相关的最优状态反馈控制律就可以直接获得,也就是说式(13)是可解的.可是,式(13)这种非线性偏微分方程的求解是十分困难的.同时,随着系统维数的增加,存储量和计算量也随之以指数形式增加,也就是平常所说的“维数灾”问题.因此,为了克服这些弱点,在第3部分提出了一种基于神经网络的自适应评判机制,来近似每个玩家的最优代价函数,从而获得相关的近似最优状态反馈控制策略.3自适应评判控制设计3.1神经网络实现本节的核心是构建并训练评判神经网络,以得到训练后的权值,从而获得每个玩家的近似最优代价函数值.首先,根据神经网络的逼近性质[25],可将每个玩家的最优代价函数J∗i(x)在紧集Ω上表示为J∗i(x)=W Tiσi(x)+ξi(x),i∈N,(14)其中:W i∈Rδ是理想权值向量,σi(x)∈Rδ是激活函数,δ是隐含层神经元个数,ξi(x)∈R是重构误差.同时,可得出每个玩家的最优代价函数梯度为∇J∗i(x)=(∇σi(x))T W i+∇ξi(x),i∈N,(15)将式(15)代入式(12),有u∗i(x)=−αi tanh(B i(x)+C i(x))+¯βi,i∈N,(16)其中:B i(x)=12αig Ti(x)(∇σi(x))T W i∈R m,C i(x)=12αig Ti(x)∇ξi(x)∈R m.然后,将式(15)代入式(13),耦合HJ方程变为W Ti∇σi(x)f(x)+(∇ξi(x))T f(x)+x T Q i x+N∑j=1((W Ti∇σi(x)+(∇ξi(x))T)g j(x)¯βj)−N∑j=1(αj W Ti∇σi(x)g j(x)tanh(B j(x)+C j(x)))−N∑j=1(αj(∇ξi(x))T g j(x)tanh(B j(x)+C j(x)))+N∑j=1S j(−αj tanh(B j(x)+C j(x))+¯βj)=0,i∈N.(17)值得注意的是,式(14)中的理想权值向量W i是未知的,也就是说式(16)中的u∗i(x)是不可解的.因此,第9期李梦花等:不对称约束多人非零和博弈的自适应评判控制1565构建如下的评判神经网络:ˆJ∗i (x)=ˆW Tiσi(x),i∈N,(18)来近似每个玩家的最优代价函数,其中ˆW i∈Rδ是估计的权值向量.同时,其梯度为∇ˆJ∗i(x)=(∇σi(x))TˆW i,i∈N.(19)考虑式(19),近似的最优控制律为ˆu∗i(x)=−αi tanh(D i(x))+¯βi,i∈N,(20)其中D i(x)=12αig Ti(x)(∇σi(x))TˆW i.同理,近似的Hamiltonian可以写为ˆHi(x,ˆW i)=ˆW T i ϕi+x T Q i x+N∑j=1(ˆW Ti∇σi(x)g j(x)¯βj)−N ∑j=1(αjˆW Ti∇σi(x)g j(x)tanh(D j(x)))+N∑j=1S j(−αj tanh(D j(x))+¯βj),i∈N,(21)其中ϕi=∇σi(x)f(x).此外,定义误差量e i=ˆH i(x,ˆW i )−H i(x,U∗,∇J∗i(x))=ˆH i(x,ˆW i).为了使e i足够小,需要训练评判网络来使目标函数E i=12e Tie i最小化.在这里,本文采用的训练准则为˙ˆW i =−γi1(1+ϕTiϕi)2(∂E i∂ˆW i)=−γiϕi(1+ϕTiϕi)2e i,i∈N,(22)其中:γi>0是评判网络的学习率,(1+ϕT iϕi)2用于归一化操作.此外,定义评判网络的权值近似误差为˜Wi=W i−ˆW i.因此,有˙˜W i =γiφi1+ϕTiϕie Hi−γiφiφT i˜W i,i∈N,(23)其中:φi=ϕi(1+ϕTiϕi),e Hi=−(∇ξi(x))T f(x)是残差项.3.2稳定性分析本节的核心是通过利用Lyapunov方法讨论评判网络权值近似误差和闭环系统状态的UUB稳定性.这里,给出以下假设:假设3∥∇ξi(x)∥ b∇ξi ,∥∇σi(x)∥ b∇σi,∥e Hi∥ b e Hi,∥W i∥ b W i,其中:b∇ξi,b∇σi,b e Hi,b W i 都是正常数,i∈N.定理1考虑系统(1),如果假设1–3成立,状态反馈控制律由式(20)给出,且评判网络权值通过式(22)进行训练,则评判网络权值近似误差˜W i是UUB 稳定的.证选取如下的Lyapunov函数:L1(t)=N∑i=1(12˜W Ti˜Wi)=N∑i=1L1i(t),(24)计算L1i(t)沿着式(23)的时间导数,即˙L1i(t)=γi˜W Tiφi1+ϕTiϕie Hi−γi˜W TiφiφTi˜Wi,i∈N,(25)利用不等式¯X T¯Y12∥¯X∥2+12∥¯Y∥2(注:¯X和¯Y都是具有合适维数的向量),并且考虑1+ϕTiϕi 1,能得到˙L1i(t)γi2(∥φTi˜Wi∥2+∥e Hi∥2)−γi˜W TiφiφTi˜Wi=−γi2˜W TiφiφTi˜Wi+γi2∥e Hi∥2,i∈N.(26)根据假设3,有˙L1i(t) −γi2λmin(φiφTi)∥˜W i∥2+γi2b2e Hi,i∈N,(27)其中λmin(·)表示矩阵的最小特征值.因此,当不等式∥˜W i∥>√b2e Hiλmin(φiφTi),i∈N(28)成立时,有˙L1i(t)<0.根据标准的Lyapunov定理[26],可知评判网络权值近似误差˜W i是UUB稳定的.证毕.定理2考虑系统(1),如果假设1–3成立,状态反馈控制律由式(20)给出,且评判网络权值通过式(22)进行训练,则系统状态x(t)是UUB稳定的.证选取如下的Lyapunov函数:L2i(t)=J∗i(x),i∈N.(29)计算L2i(t)沿着系统˙x=f(x)+N∑j=1g j(x)ˆu∗j的时间导数,即˙L2i(t)=(∇J∗i(x))T(f(x)+N∑j=1g j(x)ˆu∗j)=(∇J∗i(x))T(f(x)+N∑j=1g j(x)u∗j)+N∑j=1((∇J∗i(x))T g j(x)(ˆu∗j−u∗j)),i∈N.(30)考虑式(13),有˙L2i(t)=−x T Q i x−N∑j=1S j(u∗j)+N∑j=1((∇J∗i(x))T g j(x)(ˆu∗j−u∗j))Σi,i∈N,(31)1566控制理论与应用第40卷利用不等式¯XT ¯Y 12∥¯X ∥2+12∥¯Y ∥2,并且考虑式(15)–(16)(20),可得Σi 12N ∑j =1∥−αj tanh (D j (x ))+αj tanh (F j (x ))∥2+12N ∑j =1∥g Tj (x )((∇σi (x ))T W i +∇ξi (x ))∥2,i ∈N ,(32)其中F j (x )=B j (x )+C j (x ).然后,利用不等式∥¯X+¯Y∥2 2∥¯X ∥2+2∥¯Y ∥2,有Σi N ∑j =1(∥αj tanh (D j (x ))∥2+∥αj tanh (F j (x ))∥2)+N ∑j =1∥g Tj (x )(∇σi (x ))T W i ∥2+N ∑j =1∥g T j (x )∇ξi (x )∥2,i ∈N ,(33)其中D j (x )∈R m ,F j (x )∈R m 分别被表示为[D j 1(x )D j 2(x )···D jm (x )]T 和[F j 1(x )F j 2(x )···F jm (x )]T .易知,∀θ∈R ,tanh 2θ 1.因此,有∥tanh (D j (x ))∥2=m ∑l =1tanh 2(D jl (x )) m,(34)∥tanh (F j (x ))∥2=m ∑l =1tanh 2(F jl (x )) m.(35)同时,根据假设2–3,有Σi N ∑j =1(2α2j m +b 2g j b 2∇σi b 2W i +b 2g j b 2∇ξi ),i ∈N ,(36)根据式(2)(4)–(5),可知S j (u ∗j ) 0.于是,有˙L2i (t ) −λmin (Q i )∥x ∥2+ϖi ,i ∈N ,(37)其中ϖi =N ∑j =1(2α2j m +b 2g j b 2∇σi b 2W i +b 2g j b 2∇ξi ).因此,根据式(37)可知,当不等式∥x ∥>√ϖiλmin (Q i )成立时,有˙L2i (t )<0.即,如果x (t )满足下列不等式:∥x ∥>max {√ϖ1λmin (Q 1),···,√ϖNλmin (Q N )},(38)则,∀i ∈N ,都有˙L 2i (t )<0.同理,可得闭环系统状态x (t )也是UUB 稳定的.证毕.4仿真结果考虑如下的3–玩家连续时间非线性系统:˙x =[−1.2x 1+1.5x 2sin x 20.5x 1−x 2]+[01.5sin x 1cos x 1]u 1(x )+[1.2sin x 1cos x 2]u 2(x )+[01.1sin x 2]u 3(x ),(39)其中:x (t )=[x 1x 2]T ∈R 2是状态向量,u 1(x )∈T 1={u 1∈R :−1 u 1 2},u 2(x )∈T 2={u 2∈R :−0.2 u 2 1}和u 3(x )∈T 3={u 3∈R :−0.4 u 3 0.8}是控制输入.令Q 1=2I 2,Q 2=1.8I 2,Q 3=0.3I 2,其中I 2代表2×2维单位矩阵.同时,根据式(5)可知,α1=1.5,β1=0.5,α2=0.6,β2=0.4,α3=0.6,β3=0.2.因此,与每个玩家相关的代价函数可以表示为J i (x 0)= ∞0(x TQ i x +3∑j =1S j (u j ))d τ,i =1,2,3,(40)其中S j (u j )=2αju jβj tanh −1(z −βjαj)d z =2αj (u j −βj )tanh −1(u j −βjαj)+α2j ln (1−(u j −βj )2α2j).(41)然后,本文针对系统(39)构建3个评判神经网络,每个玩家的评判神经网络权值分别为ˆW1=[ˆW 11ˆW 12ˆW13]T ,ˆW 2=[ˆW 21ˆW 22ˆW 23]T ,ˆW 3=[ˆW 31ˆW 32ˆW33]T ,激活函数被定义为σ1(x )=σ2(x )=σ3(x )=[x 21x 1x 2x 22]T,且隐含层神经元个数为δ=3.此外,系统初始状态取x 0=[0.5−0.5]T ,每个评判神经网络的学习率分别为γ1=1.5,γ2=0.8,γ3=0.2,且每个评判神经网络的初始权值都在0和2之间选取.最后,引入探测噪声η(t )=sin 2(−1.2t )cos(0.5t )+cos(2.4t )sin 3(2.4t )+sin 5t +sin 2(1.12t )+sin 2t ×cos t +sin 2(2t )cos(0.1t ),使得系统满足持续激励条件.执行学习过程,本文发现每个玩家的评判神经网络权值分别收敛于[6.90912.99046.6961]T ,[4.89012.23475.2062]T ,[1.79450.33212.4583]T .在60个时间步之后去掉探测噪声,每个玩家的评判网络权值收敛过程如图1–3所示.然后,将训练好的权值代入式(20),能得到每个玩家的近似最优控制律,将其应用到系统(39),经过10个时间步之后,得到的状态轨迹和控制轨迹分别如图4–5所示.由图4可知,系统状态最终收敛到了平衡点.由图5可知,每个玩家的控制轨迹都没有超出预定的边界,并且可以观察到u 1,u 2和u 3分别收敛于0.5,0.4和0.2.综上所述,仿真结果验证了所提方法的有效性.第9期李梦花等:不对称约束多人非零和博弈的自适应评判控制1567䇴 㖁㔌U / s图1玩家1的评判网络权值收敛过程Fig.1Convergence process of the critic network weights forplayer1䇴 㖁㔌U / s图2玩家2的评判网络权值收敛过程Fig.2Convergence process of the critic network weights forplayer2﹣䇴 㖁㔌U / s图3玩家3的评判网络权值收敛过程Fig.3Convergence process of the critic network weights forplayer 35结论本文首次将不对称约束应用到连续时间非线性系统的多人非零和博弈问题中.首先,获得了最优状态反馈控制律和耦合HJ 方程,并且为了解决不对称约束问题,建立了一种新的非二次型函数.值得注意的是,当系统状态为零时,最优控制策略是不为零的.其次,由于耦合HJ 方程不易求解,提出了一种基于神经网络的自适应评判算法来近似每个玩家的最优代价函数,从而获得相关的近似最优控制律.在实现过程中,用单一评判网络结构代替了经典的执行–评判结构,并且建立了一种新的权值更新规则.然后,利用Lyap-unov 理论讨论了评判网络权值近似误差和系统状态的UUB 稳定性.最后,仿真结果验证了所提算法的可行性.在未来的工作中,会考虑将事件驱动机制引入到连续时间非线性系统的不对称约束多人非零和博弈问题中,并且将该研究内容应用到污水处理系统中也是笔者的一个重点研究方向.﹣0.5﹣0.4﹣0.3﹣0.2﹣0.10.00.10.20.00.10.20.30.40.5(U )Y 1(U )Y 2图4系统(39)的状态轨迹Fig.4State trajectory of the system (39)0.00.51.01.52.00.00.20.40.60.81.01.200.012345678910﹣0.40.4﹣0.20.2(U )V 3(U )V 2(U )V 1U / s 012345678910U / s 012345678910U / s (c)(b)(a)(U )V 1(U )V 2(U )V 3图5系统(39)的控制轨迹Fig.5Control trajectories of the system (39)1568控制理论与应用第40卷参考文献:[1]WERBOS P J.Beyond regression:New tools for prediction andanalysis in the behavioral sciences.Cambridge:Harvard Universi-ty,1974.[2]HONG Chengwen,FU Yue.Nonlinear robust approximate optimaltracking control based on adaptive dynamic programming.Control Theory&Applications,2018,35(9):1285–1292.(洪成文,富月.基于自适应动态规划的非线性鲁棒近似最优跟踪控制.控制理论与应用,2018,35(9):1285–1292.)[3]CUI Lili,ZHANG Yong,ZHANG Xin.Event-triggered adaptive dy-namic programming algorithm for the nonlinear zero-sum differential games.Control Theory&Applications,2018,35(5):610–618.(崔黎黎,张勇,张欣.非线性零和微分对策的事件触发自适应动态规划算法.控制理论与应用,2018,35(5):610–618.)[4]WANG D,HA M,ZHAO M.The intelligent critic framework foradvanced optimal control.Artificial Intelligence Review,2022,55(1): 1–22.[5]WANG D,QIAO J,CHENG L.An approximate neuro-optimal solu-tion of discounted guaranteed cost control design.IEEE Transactions on Cybernetics,2022,52(1):77–86.[6]YANG X,HE H.Adaptive dynamic programming for decentralizedstabilization of uncertain nonlinear large-scale systems with mis-matched interconnections.IEEE Transactions on Systems,Man,and Cybernetics:Systems,2020,50(8):2870–2882.[7]ZHAO B,LIU D.Event-triggered decentralized tracking control ofmodular reconfigurable robots through adaptive dynamic program-ming.IEEE Transactions on Industrial Electronics,2020,67(4): 3054–3064.[8]WANG Ding.Research progress on learning-based robust adaptivecritic control.Acta Automatica Sinica,2019,45(6):1037–1049.(王鼎.基于学习的鲁棒自适应评判控制研究进展.自动化学报, 2019,45(6):1037–1049.)[9]ZHANG Huaguang,ZHANG Xin,LUO Yanhong,et al.An overviewof research on adaptive dynamic programming.Acta Automatica Sini-ca,2013,39(4):303–311.(张化光,张欣,罗艳红,等.自适应动态规划综述.自动化学报, 2013,39(4):303–311.)[10]L¨U Yongfeng,TIAN Jianyan,JIAN Long,et al.Approximate-dynamic-programming H∞controls for multi-input nonlinear sys-tem.Control Theory&Applications,2021,38(10):1662–1670.(吕永峰,田建艳,菅垄,等.非线性多输入系统的近似动态规划H∞控制.控制理论与应用,2021,38(10):1662–1670.)[11]AN P,LIU M,WAN Y,et al.Multi-player H∞differential gameusing on-policy and off-policy reinforcement learning.The16th In-ternational Conference on Control and Automation.Electr Network: IEEE,2020,10:1137–1142.[12]REN H,ZHANG H,MU Y,et al.Off-policy synchronous iterationIRL method for multi-player zero-sum games with input constraints.Neurocomputing,2020,378:413–421.[13]LIU D,LI H,WANG D.Online synchronous approximate optimallearning algorithm for multiplayer nonzero-sum games with unknown dynamics.IEEE Transactions on Systems,Man,and Cybernetics: Systems,2014,44(8):1015–1027.[14]V AMVOUDAKIS K G,LEWIS F L.Non-zero sum games:Onlinelearning solution of coupled Hamilton-Jacobi and coupled Riccati equations.IEEE International Symposium on Intelligent Control.Denver,CO,USA:IEEE,2011,9:171–178.[15]ZHANG H,ZHANG K,XIAO G,et al.Robust optimal controlscheme for unknown constrained-input nonlinear systems via a plug-n-play event-sampled critic-only algorithm.IEEE Transactions on Systems,Man,and Cybernetics:Systems,2020,50(9):3169–3180.[16]HUO X,KARIMI H R,ZHAO X,et al.Adaptive-critic design fordecentralized event-triggered control of constrained nonlinear inter-connected systems within an identifier-critic framework.IEEE Trans-actions on Cybernetics,2022,52(8):7478–7491.[17]YANG X,HE H.Event-triggered robust stabilization of nonlin-ear input-constrained systems using single network adaptive critic designs.IEEE Transactions on Systems,Man,and Cybernetics:Sys-tems,2020,50(9):3145–3157.[18]WANG L,CHEN C L P.Reduced-order observer-based dynamicevent-triggered adaptive NN control for stochastic nonlinear systems subject to unknown input saturation.IEEE Transactions on Neural Networks and Learning Systems,2021,32(4):1678–1690.[19]YANG X,ZHU Y,DONG N,et al.Decentralized event-driven con-strained control using adaptive critic designs.IEEE Transactions on Neural Networks and Learning Systems,2022,33(10):5830–5844.[20]WANG D,ZHAO M,QIAO J.Intelligent optimal tracking withasymmetric constraints of a nonlinear wastewater treatment system.International Journal of Robust and Nonlinear Control,2021,31(14): 6773–6787.[21]LI M,WANG D,QIAO J,et al.Neural-network-based self-learningdisturbance rejection design for continuous-time nonlinear con-strained systems.Proceedings of the40th Chinese Control Confer-ence.Shanghai,China:IEEE,2021,7:2179–2184.[22]SU H,ZHANG H,JIANG H,et al.Decentralized event-triggeredadaptive control of discrete-time nonzero-sum games over wireless sensor-actuator networks with input constraints.IEEE Transactions on Neural Networks and Learning Systems,2020,31(10):4254–4266.[23]YANG X,HE H.Event-driven H∞-constrained control using adap-tive critic learning.IEEE Transactions on Cybernetics,2021,51(10): 4860–4872.[24]ABU-KHALAF M,LEWIS F L.Nearly optimal control laws for non-linear systems with saturating actuators using a neural network HJB approach.Automatica,2005,41(5):779–791.[25]HORNIK K,STINCHCOMBE M,WHITE H.Universal approxima-tion of an unknown mapping and its derivatives using multilayer feed-forward networks.Neural Networks,1990,3(5):551–560.[26]LEWIS F L,JAGANNATHAN S,YESILDIREK A.Neural NetworkControl of Robot Manipulators and Nonlinear Systems.London:Tay-lor&Francis,1999.作者简介:李梦花博士研究生,目前研究方向为自适应动态规划、智能控制,E-mail:*********************;王鼎教授,博士生导师,目前研究方向为智能控制、强化学习,E-mail:*****************.cn;乔俊飞教授,博士生导师,目前研究方向为智能计算、智能优化控制,E-mail:***************.cn.。
华为AP7050DE无线无线接入点数据手册说明书
Huawei Access Point DatasheetMU-MIMOThe AP supports MU-MIMO. MU-MIMO technology allows an AP to send data to multiple STAs at the same time (currently, most802.11n/11ac Wave 1 APs can only send data to one STA simultaneously). The technology marks the start of the 802.11ac Wave 2 era.GE accessThe AP supports the 80-MHz bandwidth mode. Frequency bandwidth increase brings extended channels and more sub-carriers for data transmission, and a 2.16 times higher rate. Support for High Quadrature Amplitude Modulation (HQAM) at 256-QAM and 4 x 4 MIMO increases the 5 GHz radio rate to 1.73 Gbit/s. The throughput of the AP is four times that of traditional 802.11n APs under the similar conditions.Cloud-based managementHuawei Cloud Managed Network (CMN) Solution consists of the cloud management platform and a full range of cloud managed network devices. The cloud management platform provides various functions including management of APs, tenants, applications, and licenses, network planning and optimization, device monitoring, network service configuration, and value-added services.High Density Boost technologyHuawei uses the following technologies to address challenges in high-density scenarios, including access problems, data congestion, and poor roaming experience:•SmartRadio for air interface optimizationˉ Load balancing during smart roaming: The load balancing algorithm can work during smart roaming for load balancing detection among APs on the network after STA roaming to adjust the STA load on each AP, improving network stability.ˉ Intelligent DFA technology: The dynamic frequency assignment (DFA) algorithm is used to automatically detect adjacent-channel and co-channel interference, and identify any 2.4 GHz redundant radio. Through automatic inter-AP negotiation, the redundant radio is automatically switched to another mode (dual-5G AP models support 2.4G-to-5G switchover) or is disabled to reduce 2.4 GHz co-channel interference and increase the system capacity.ˉ Intelligent conflict optimization technology: The dynamic enhanced distributed channel access (EDCA) and airtime scheduling algorithms are used to schedule the channel occupation time and service priority of each user. This ensures that each user isassigned relatively equal time for using channel resources and user services are scheduled in an orderly manner, improving service processing efficiency and user experience.•Air interface performance optimizationˉIn high-density scenarios where many users access the network, increased number of low-rate STAs consumes more resources on the air interface, reduces the AP capacity, and lowers user experience. Therefore, Huawei APs will check the signal strength ofSTAs during access and rejects access from weak-signal STAs. At the same time, the APs monitor the rate of online STAs in real time and forcibly disconnect low-rate STAs so that the STAs can reassociate with APs that have stronger signals. The terminalaccess control technology can increase air interface use efficiency and allow access from more users.•5G-prior access (Band steering)ˉThe APs support both 2.4G and 5G frequency bands. The 5G-prior access function enables an AP to steer STAs to the 5 GHz frequency band first, which reduces load and interference on the 2.4 GHz frequency band, improving the user experience.Huawei AP7050DEAccess Point Datasheet 03Wired and wireless dual security guaranteeTo ensure data security, Huawei APs integrate wired and wireless security measures and provide comprehensive security protection.•Authentication and encryption for wireless accessˉThe APs support WEP, WPA/WPA2–PSK, WPA/WPA2–PPSK, WPA/WPA2–802.1X, and WAPI authentication/encryption modes to ensure security of the wireless network. The authentication mechanism is used to authenticate user identities so that onlyauthorized users can access network resources. The encryption mechanism is used to encrypt data transmitted over wireless links to ensure that the data can only be received and parsed by expected users.•Analysis on non-Wi-Fi interference sourcesˉHuawei APs can analyze the spectrum of non-Wi-Fi interference sources and identify them, including baby monitors, Bluetooth devices, digital cordless phones (at 2.4 GHz frequency band only), wireless audio transmitters (at both the 2.4 GHz and 5 GHzfrequency bands), wireless game controllers, and microwave ovens. Coupled with Huawei eSight, the precise locations of theinterference sources can be detected, and the spectrum of them displayed, enabling the administrator to remove the interference in a timely manner.•Rogue device monitoringˉHuawei APs support WIDS/WIPS, and can monitor, identify, defend, counter, and perform refined management on the rogue devices, to provide security guarantees for air interface environment and wireless data transmission.•AP access authentication and encryptionˉThe AP access control ensures validity of APs. The CAPWAP link protection and DTLS encryption provide security assurance, improving data transmission security between the AP and the AC.Automatic radio calibrationAutomatic radio calibration allows an AP to collect signal strength and channel parameters of surrounding APs and generate AP topology according to the collected data. Based on interference from authorized APs, rogue APs, and non-Wi-Fi interference sources, each AP automatically adjusts its transmit power and working channel to make the network operate at the optimal performance. In this way, network reliability and user experience are improved.Automatic application identificationHuawei APs support smart application control technology and can implement visualized control on Layer 4 to Layer 7 applications.•Traffic identificationˉCoupled with Huawei ACs, the APs can identify over 1600 common applications in various office scenarios. Based on the identification results, policy control can be implemented on user services, including priority adjustment, scheduling, blocking, and rate limiting to ensure efficient bandwidth resource use and improve quality of key services.•Traffic statistics collectionˉTraffic statistics of each application can be collected globally, by SSID, or by user, enabling the network administrator to know application use status on the network. The network administrator or operator can implement visualized control on service applications on smart terminals to enhance security and ensure effective bandwidth control.Huawei AP7050DEAccess Point Datasheet 04Basic Specifications......................................................................................................................... //Hardware specificationsItem DescriptionTechnical specificationsDimensions (H x W x D) 53 mm x 220 mm x 220 mmWeight 1.30 kgInterface type2 x 10/100/1000M self-adaptive Ethernet interface (RJ45)1 x Management console port (RJ45)1 x USB interfaceBuilt-in Bluetooth BLE4.1LED indicator Indicates the power-on, startup, running, alarm, and fault status of the system.Power specifications Power input 12 V DC ± 10%PoE power supply: in compliance with IEEE 802.3atMaximum powerconsumption24 W (excluding the output power of the USB port)The actual maximum power consumption depends on local laws and regulations.Environmental specifications Operating temperature –10°C to +50°CStorage temperature–40°C to +70°COperating humidity 5% to 95% (non-condensing) Dustproof andwaterproof grade IP41Altitude –60 m to +5000 m Atmospheric pressure 53 kPa to 106 kPaRadio specifications Antenna type Built-in smart antennasAntenna gain2.4 GHz:2 dBi5 GHz: 3 dBiMaximum number ofSSIDs for each radio≤ 16Maximum number ofusers≤ 512The actual number of users varies according to the environment.NOTENOTEItem DescriptionRadio specificationsMaximum transmitpower2.4G: 26 dBm (combined power)5G: 27 dBm (combined power)The actual transmit power depends on local laws and regulations.Power increment 1 dBmReceiver sensitivity2.4 GHz 802.11b:–104 dBm @ 1 Mbit/s;–97 dBm@ 11 Mbit/s2.4 GHz 802.11g:-97 dBm @ 6 Mbit/s; -78 dBm @ 54 Mbit/s2.4 GHz 802.11n (HT20):-97 dBm @ MCS0;-73 dBm @ MCS312.4 GHz 802.11n(HT40):-95 dBm @ MCS0;-71 dBm @ MCS315 GHz 802.11a:–97 dBm @6 Mbit/s;–79 dBm@ 54 Mbit/s5 GHz 802.11n (HT20):-97 dBm @ MCS0;-72 dBm @ MCS315 GHz 802.11n (HT40):-94 dBm @ MCS0;-68 dBm @ MCS315 GHz 802.11ac (VTH20):-97 dBm @ MCS0NSS1;-70 dBm @ MCS8NSS45 GHz 802.11ac (VTH40):-94 dBm @ MCS0NSS1; -64 dBm @ MCS9NSS45 GHz 802.11ac (VTH80):-90 dBm @ MCS0NSS1; -61 dBm @ MCS9NSS45 GHz 802.11ac (VTH160):-85 dBm @ MCS0NSS1; -58 dBm @ MCS9NSS2NOTEBasic Specifications......................................................................................................................... //Software s pecificationsFat/Fit AP modeItem DescriptionWLAN features Compliance with IEEE 802.11a/b/g/n/ac/ac Wave 2Maximum rate of up to 2.53 Gbit/sMaximum ratio combining (MRC)Space time block code (STBC)Cyclic Delay Diversity (CDD)/Cyclic Shift Diversity (CSD)BeamformingMU-MIMOLow-density parity-check (LDPC)Maximum-likelihood detection (MLD)Frame aggregation, including A-MPDU (Tx/Rx) and A-MSDU (Tx/Rx)802.11 dynamic frequency selection (DFS)Short guard interval (GI) in 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 80+80 MHz modesPriority mapping and packet scheduling based on a Wi-Fi Multimedia (WMM) profile to implement priority-based data processing and forwardingAutomatic and manual rate adjustmentWLAN channel management and channel rate adjustmentAutomatic channel scanning and interference avoidanceService set identifier (SSID) hidingSignal sustain technology (SST)Unscheduled automatic power save delivery (U-APSD)Control and Provisioning of Wireless Access Points (CAPWAP) in Fit AP modeAutomatic login in Fit AP modeExtended Service Set (ESS) in Fit AP modeWireless distribution system (WDS) in Fit AP modeMesh networking in Fit AP modeMulti-user CACHotspot2.0802.11k and 802.11v smart roaming802.11r fast roaming (≤ 50 ms)WAN authentication escape. In local forwarding mode, this function retains the online state of existing STAs and allows access of new STAs when APs are disconnected from an AC, ensuring service continuity.Item DescriptionNetwork features Compliance with IEEE 802.3abAuto-negotiation of the rate and duplex mode and automatic switchover between the Media Dependent Interface (MDI) and Media Dependent Interface Crossover (MDI-X)Compliance with IEEE 802.1qSSID-based VLAN assignmentVLAN trunk on uplink Ethernet portsManagement channel of the AP uplink port in tagged and untagged modeDHCP client, obtaining IP addresses through DHCPTunnel data forwarding and direct data forwardingSTA isolation in the same VLANAccess control lists (ACLs)Link Layer Discovery Protocol (LLDP)Uninterrupted service forwarding upon CAPWAP channel disconnection in Fit AP modeUnified authentication on the AC in Fit AP modeAC dual-link backup in Fit AP modeNetwork Address Translation (NAT) in Fat AP modeIPv6 in Fit AP modeSoft Generic Routing Encapsulation (GRE)IPv6 Source Address Validation Improvements (SAVI)QoS features Priority mapping and packet scheduling based on a Wi-Fi Multimedia (WMM) profile to implement priority-based data processing and forwardingWMM parameter management for each radioWMM power savingPriority mapping for upstream packets and flow-based mapping for downstream packetsQueue mapping and schedulingUser-based bandwidth limitingAdaptive bandwidth management (automatic bandwidth adjustment based on the user quantity and radio environment) to improve user experienceSmart Application Control (SAC) in Fit AP modeAirtime schedulingSupport for Microsoft Lync APIs and high voice call quality through Lync API identification and schedulingItem DescriptionSecurity features Open system authenticationWEP authentication/encryption using a 64-bit, 128-bit, or 152-bit encryption keyWPA/WPA2-PSK authentication and encryption (WPA/WPA2 personal edition)WPA/WPA2-802.1x authentication and encryption (WPA/WPA2 enterprise edition)WPA-WPA2 hybrid authenticationWPA/WPA2-PPSK authentication and encryption in Fit AP modeWAPI authentication and encryptionWireless intrusion detection system (WIDS) and wireless intrusion prevention system (WIPS), including rogue device detection and countermeasure, attack detection and dynamic blacklist, and STA/AP blacklist and whitelist802.1x authentication, MAC address authentication, and Portal authenticationDHCP snoopingDynamic ARP Inspection (DAI)IP Source Guard (IPSG)802.11w Protected Management Frames (PMFs)Application identificationMaintenance features Unified management and maintenance on the AC in Fit AP modeAutomatic login and configuration loading, and plug-and-play (PnP) in Fit AP mode WDS zero-configuration deployment in Fit AP modeMesh network zero-configuration deployment in Fit AP modeBatch upgrade in Fit AP modeTelnetSTelnet using SSH v2SFTP using SSH v2Local AP management through the serial interfaceWeb local AP management through HTTP or HTTPS in Fat AP modeReal-time configuration monitoring and fast fault location using the NMSSNMP v1/v2/v3 in Fat AP modeSystem status alarmNetwork Time Protocol (NTP) in Fat AP modeBYOD The AP supports bring your own device (BYOD) only in Fit AP mode.Identifies the device type according to the organizationally unique identifier (OUI) in the MAC address. Identifies the device type according to the user agent (UA) information in an HTTP packet. Identifies the device type according to DHCP options.The RADIUS server delivers packet forwarding, security, and QoS policies according to the device type carried in the RADIUS authentication and accounting packets.NOTEItem DescriptionLocation service The AP supports the locating service only in Fit AP mode. Locates tags manufactured by AeroScout or Ekahau. Locates Wi-Fi terminals.Works with eSight to locate rogue devices.Spectrum analysis The AP supports spectrum analysis only in Fit AP mode.Identifies interference sources such as baby monitors, Bluetooth devices, digital cordless phones (at 2.4 GHz frequency band only), wireless audio transmitters (at both the 2.4 GHz and 5 GHz frequency bands), wireless game controllers, and microwaves.Works with eSight to perform spectrum analysis on interference sources.Cloud-based management modeItem DescriptionWLAN features Compliance with IEEE 802.11a/b/g/n/ac/ac Wave 2Maximum rate of up to 2.53 Gbit/sMaximum ratio combining (MRC)Space time block code (STBC)BeamformingLow-density parity-check (LDPC)Maximum-likelihood detection (MLD)Frame aggregation, including A-MPDU (Tx/Rx) and A-MSDU (Tx/Rx)802.11 dynamic frequency selection (DFS)Priority mapping and packet scheduling based on a Wi-Fi Multimedia (WMM) profile to implement priority-based data processing and forwardingWLAN channel management and channel rate adjustmentFor detailed management channels, see the Country Code & Channel Compliance Table.Automatic channel scanning and interference avoidanceService set identifier (SSID) hidingSignal sustain technology (SST)Unscheduled automatic power save delivery (U-APSD)Automatic loginNOTENOTENOTEItem DescriptionNetwork features Compliance with IEEE 802.3abAuto-negotiation of the rate and duplex mode and automatic switchover between the Media Dependent Interface (MDI) and Media Dependent Interface Crossover (MDI-X)Compliance with IEEE 802.1qSSID-based VLAN assignmentDHCP client, obtaining IP addresses through DHCPSTA isolation in the same VLANAccess control lists (ACLs)Unified authentication on the Agile ControllerNetwork Address Translation (NAT)QoS features Priority mapping and packet scheduling based on a Wi-Fi Multimedia (WMM) profile to implement priority-based data processing and forwardingWMM parameter management for each radioWMM power savingPriority mapping for upstream packets and flow-based mapping for downstream packetsQueue mapping and schedulingUser-based bandwidth limitingAirtime schedulingSecurity features Open system authenticationWEP authentication/encryption using a 64-bit, 128-bit, or 152-bit encryption key WPA/WPA2-PSK authentication and encryption (WPA/WPA2 personal edition) WPA/WPA2-802.1x authentication and encryption (WPA/WPA2 enterprise edition) WPA-WPA2 hybrid authenticationWPA/WPA2-PPSK authentication and encryption802.1x authentication, MAC address authentication, and Portal authentication DHCP snoopingDynamic ARP Inspection (DAI)IP Source Guard (IPSG)Item DescriptionMaintenance features Unified management and maintenance on the Agile Controller Automatic login and configuration loading, and plug-and-play (PnP) Batch upgradeTelnetSTelnet using SSH v2SFTP using SSH v2Local AP management through the serial interfaceWeb local AP management through HTTP or HTTPSReal-time configuration monitoring and fast fault location using the NMS System status alarmNetwork Time Protocol (NTP)Standards complianceItem DescriptionSafety standards UL60950–1CAN/CSA22.2No.60950-1IEC60950–1 EN60950–1GB4943Radio standards ETSI EN 300 328 ETSI EN 301 893 FCC Part 15C: 15.247 FCC Part 15C: 15.407 RSS-210 AS/NZS 4268EMC standards EN 301 489–1 EN 301 489–17 ETSI EN 60601-1-2 FCC Part 15 ICES-003 YD/T 1312.2-2004 ITU k.20 GB 9254 GB 17625.1 AS/NZS CISPR22 EN 55022 EN 55024 CISPR 22 CISPR 24 IEC61000-4-6 IEC61000-4-2IEEE standards IEEE 802.11a/b/g IEEE 802.11n IEEE 802.11acIEEE 802.11h IEEE 802.11d IEEE 802.11eIEEE 802.11k IEEE 802.11u IEEE 802.11v IEEE 802.11w IEEE 802.11rSecurity standards 802.11i,Wi-Fi Protected Access 2(WPA2),WPA802.1XAdvanced Encryption Standards(AES),Temporal Key Integrity Protocol(TKIP) EAP Type(s)EMF CENELEC EN62311CENELEC EN50385OET65RSS-102FCC Part1&2FCC KDB SeriesRoHS Directive2002/95/EC & 2011/65/EU REACH Regulation1907/2006/ECWEEE Directive2002/96/EC & 2012/19/EUAP7050DE Antennas Pattern2.4G (PHI=0)2.4G (PHI=90)5G (PHI=0)5G (PHI=90)Professional Service and Supportplanning tools deliver expert network design and optimization services using the most professionalin the industry. Backed by fifteen years of continuous investment in wireless technologies, extensive network planning and optimization experience, and rich expert resources, Huawei helps customers:Design, deploy, and operate a high-performance network that is reliable and secure.Maximize return on investment and reduce operating expenses.Copyright © Huawei Technologies Co., Ltd. 2017. All rights reserved.No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.Trademark Notice, HUAWEI, and are trademarks or registered trademarks of Huawei Technologies Co., Ltd.Other trademarks, product, service and company names mentioned are the property of their respective owners.General DisclaimerThe information in this document may contain predictive statements including, withoutlimitation, statements regarding the future financial and operating results, future productportfolio, new technology, etc. There are a number of factors that could cause actual resultsand developments to differ materially from those expressed or implied in the predictivestatements. Therefore, such information is provided for reference purpose only andconstitutes neither an offer nor an acceptance. Huawei may change the information at anytime without notice.。
DSGE学习方法
DSGE(0)我相信来这个版块里面的研究生没有不知道DSGE的,Dynamic stochastic general equilibrium,中文叫“动态随机一般均衡”。
DSGE模型出现于Kyland and Prescott (1982)。
这篇论文开创了real business cycle学派,属于第三次新古典发起的对凯恩斯主义的攻击。
第一波和第二波分别是1968年的弗里德曼货币学派革命和1976年的理性预期革命。
第三次的RBC革命基本上把整个旧凯恩斯主义葬送了。
新凯恩斯学派实际上在1970s就产生了,但是跟随者并不多,新凯恩斯学派在80s和90s大量吸收RBC学派的内容,并且承接了DSGE 建模的方式,90s年代中期形成了“新新古典综合”(New Neoclassical Synthesis)。
這不是一单独的学派,而是指的两个学派的一种融合和吸收。
因为这个学术运动是新凯恩斯学派推动的,所以有的学者也认为真正的新凯恩斯学派的产生是差不多在RBC革命的10年之后。
这篇文章我主要不讨论这两个学派和他们的综合,这个要说的话就可以写成篇论文了。
我在这篇文章里面只提供一个DSGE模型的建设性路线,因为发现大多数同学都不知道如何入手,再加上学校开课不同,数学储备不同,起点也大不相同。
我这篇文章的出发点是从基础入门的同学的观点出发,如果你想要做DSGE研究,这篇文章就应该适合你。
我研究的兴趣是给Emerging market economy建立DSGE模型,比如中国大陆,东欧国家等。
这个话题以后再谈,这里我们谈一些技术性的东西。
数学,数学,数学我可以很负责地说,干经济学博士,拼的就是数学。
真正厉害的经济学博士转物理和工程学专业都没有问题。
但我意识不是说我们需要数学家来搞经济学,我意思是我们需要很懂数学的经济学家。
经济学博士花三分之一的学习时间在数学上面完全是应该的。
所以虽然我说这是介绍给入门的朋友,但是也是要求你至少都是硕士阶段数学学扎实了的。
诺瓦科技无线LED控制卡LED多媒体播放器TB2详细参数说明书
ieee-adaptive optimal control for linear discrete time-varying system
Adaptive Optimal Control for Linear Discrete Time-Varying Systems Shuzhi Sam Ge1,Chen Wang1,Yanan Li2,Tong Heng Lee3and Marcelo H.Ang Jr.4Abstract:In this paper,adaptive optimal control is pro-posed for linear discrete time-varying(LDTV)systems sub-ject to unknown system dynamics.The idea of the method is a direct application of the Q-learning adaptive dynamic programming for time-varying systems.In order to derive the optimal control policy,an actor-critic structure is constructed and the time-varying least square method is adopted for parameter adaptation.The derived control policy robustly stabilizes the time-varying system and guarantees an optimal control performance.As no particular system information is required throughout the process,the proposed method provides a feasible solution to a large variety of applications. The validity of the proposed method is verified through simulation studies.Index Terms–adaptive dynamic programming;adaptive optimal control;LDTV systemsI.I NTRODUCTIONIn the literature of optimal control,two approaches are most widely studied,i.e.,classical optimal control based on maximum principle[1],[2]and dynamic programming[3]. In classical optimal control,afinite or infinite cost function is defined to describe the control performance,and the control policy is generated by solving the famous algebraic Riccati equation(ARE)where the state-space model of the system is assumed to be known.In dynamic programming[3],the multi-stage optimization technique is implemented where the optimal solution is acquired by solving a sequence of partitioned sub-problems.In the above conventional optimal control methods,the system information is assumed to be known,which indicates that the control engineer needs to make an effort to identify the system model in order to build an optimal control.This process is usually quite tedious and sensitive to system uncertainties and disturbance,making it not desirable in real applications.In addition,considering the time-varying nature of most system models,traditional methods are not practical 1Shuzhi Sam Ge and Chen Wang are with the Social Robotics Lab,Inter-active&Digital Media Institute(IDMI)and the Department of Electrical& Computer Engineering,National University of Singapore,Singapore117576 samge@.sg,wang chen09@.sg2Yanan Li is with NUS Graduate School for Integrative Sciences and Engineering(NGS),National University of Singapore,Singapore119613 liyanan84@.sg3Tong Heng Lee is with the Department of Electrical&Comput-er Engineering,National University of Singapore,Singapore117576 eleleeth@.sg4Marcelo H.Ang Jr.is with the Department of Mechanical Engineering,National University of Singapore,Singapore119260 mpeangh@.sgin most situations due to the off-line optimization and slow response to parameter variations[4].To tackle this problem, adaptive dynamic programming(ADP)or actor-critic learn-ing is proposed and developed in[5],[6],[7],[8],[9].The idea of ADP is constructed by resembling how individual biological system reacts to the surrounding environments [10],[11],[12],[13].Under the structure of ADP,the control system is considered to include agents that are able to make decisions and modify their actions according to the environment stimuli.The action is strengthened or depressed in accordingly to the types of stimuli(positive reinforcement or negative reinforcement).Due to their unique critic-actor structure,an optimal control policy can be generated with partial or none information of the system.This is a heuristic process where an agent tries to maximize its future rewards. In the viewpoint of control engineering,the maximization of reward is equivalent to the minimization of a control cost.Among all the ADP approaches,most recognized ADP algorithms are the heuristic dynamic programming(HDP) [14],[15],[16],globalized DHP(GDHP)[17],[18],action-dependent heuristic dynamic programming(ADHDP)[6] or Q-learning[19],[20],and dual-heuristic programming (DHP).For discrete-time systems,ADHDP or Q-learning is an online iterative learning method which does not rely on the specific plant model to be controlled.Due to its unique online learning and control structure,it has been widely applied in many researchfields,such as nonzero-sum games [21],robotic arm control[22],and optimal output feedback control[23].The idea of the proposed adaptive optimal control is similar to[20],[21].However,instead of developing an adaptive optimal control for a time-invariant system,we consider the time-varying nature of the actual model and try to solve the following problems:a)the time-varying system parameters are not computationally tractable in practice;b)when the parameters of the model change over time, optimized steady-state solutions may be inappropriate;and c) in some special cases(e.g.,model fault or system failure),the model may undergo a sudden change during the operation. Common solutions such as those in[21]can be used by resetting the control and updating the control policy based on a new batch of data.However,they can be too conservative in the sense that the execution of the optimal policy will be delayed and fail to handle such changes.To address these problems,an adaptive optimal control is proposed by taking time-varying parameters into account, such that a different set of parameters and control policy are implemented for each adaptation step.The decision making and policy updating require little computation cost,making 66978-1-4799-1075-5/13/$31.00c 2013IEEEthe proposed method feasible in practical implementations.Based on the above discussion,we highlight the contribu-tions of this paper as follows:(i)the time-varying system model is considered to becompletely unknown for the adaptive optimal control design,and the optimal control policy is generated based on the policy iteration;(ii)the recursive time-varying least square method is adopt-ed to derive the optimal control policy such that the online adaptation is achieved;and(iii)two general cases of time-varying models are consid-ered in the simulation,which verify that the proposed method is able to handle both the parameter variation and model uncertainties.The rest of the paper is organized as follows.In Section 2,the problem under study is formulated and the Q-function method for time-varying systems is described.In Section3, adaptive optimal control is developed for the time-varying system and the optimal policy is obtained subject to unknown system model.In Section4,the validity of the proposed method is verified through simulation studies.Section5 concludes this paper.II.P ROBLEM F ORMULATION AND P RELIMINARIES A.System DescriptionConsider the following LDTV systemx(k+1)=A(k)x(k)+B(k)u(k)y(k)=C(k)x(k)(1) where k denotes the time instant,x(k)∈R n is the system state,u(t)∈R m is the system input,y(t)∈R l is the system output,and A(k),B(k),and C(k)are time-varying matrices which are stabilizable.The optimal control problem can be formulated by design-ing a control in the following formu(k)=−L(k)x(k)(2) which minimizes the below cost functionJ=∞k=1[x T(k)S(k)x(k)+u T(k)R(k)u(k)](3)where S(k)∈R n×n and R(k)∈R m×m are the weights of the state and the input which satisfy S(k)=S(k)T≥0and R(k)=R(k)T>0,and L(k)is the control gain.In classical optimal control,if the system information (A(k)and B(k))is completely known,the optimal control policy u(k)can be obtained by solving the following discrete algebraic Riccati equation(DARE)P(k)=A T(k)P(k+1)A(k)+S(k)−A T(k)P(k+1)B(k)[R(k)+B T P(k+1)B(k)]−1B T(k)P(k+1)A(k)(4)The optimal feedback gain L(k)can be further derived by L(k)=[R(k)+B T(k)P(k+1)B(k)]−1×B T(k)P(k+1)A(k)(5) Remark1:Due to the time-varying nature and nonlinear-ities of most plant models,it is not feasible to use this off-line method in a real application scenario.In practice, the optimal solution to the DARE is computed by using system parameters at the last time step and approximated by a steady-state solution.This method reduces the cost of the numerical computation to some extent.However,due to the reliance on the assumption that the time-varying matrices A(k)and B(k)are known,this method is still limited in practical applications.B.Optimal Principle and Q-Function for Time-Varying LQR ProblemAs discussed in the previous section,the conventional off-line design of optimal control is usually time-consuming and suffers from the slow response to parameter variations. In the following,we will formulate this problem using the Bellman’s principle of optimality and derive an online policy using the concept of Q-functions[6],[20].Consider the following infinite horizon value functionV(x(k))=∞i=k[x T(i)S(i)x(i)+u T(i)R(i)u(i)](6) The goal is to determine the optimal control policy u∗(k) such thatu∗(k)=arg minu(k)V(x(k))(7)Assuming that u∗(k)exists,it is well known that the corre-sponding cost value V∗(x(k))=minu(k)V(x(k))is quadratic in the state with the following formV∗(x(k))=x(k)T P(k)x(k)(8) where P(k)is a time-varying matrix.The cost-to-go function can be defined asV(x(k))=g(x(k),u(k))+V∗(x(k+1))=x T(k)S(k)x(k)+u T(k)R(k)u(k)+x T(k+1)P(k+1)x(k+1)=x(k)u(k)TS(k)00R(k)x(k)u(k)+x(k)u(k)TA T(k)B T(k)P(k+1)A T(k)B T(k)Tx(k)u(k)=x(k)u(k)TH(k)x(k)u(k)(9)where g(x(k),u(k))=x T(k)S(k)x(k)+u T(k)R(k)u(k)is the utility function during the k-th step.H(k)in Eq.(9)can2013I EEE C onference on C ybernetics and Intelligent Systems(C IS)67be further written asH(k)=H xx H xuH ux H uu(10)where H xx=A T(k)P(k+1)A(k)+S(k),H xu=H T ux= A T(k)P(k+1)B(k),and H uu=B T(k)P(k+1)B(k)+ R(k).The optimal control policy can be acquired byu(k)=−L(k)x(k)=−∂V(x(k))∂u(k)=−H−1uu H ux x(k)(11) Eqs.(10)and(11)are the main equations needed to obtain the optimal control policy.Note that if H can be obtained using an online identification method,the system dynamics will no longer be needed.In the following,we will show how to formulate the optimal control problem using the Q-function based optimal principle,which will be further used to approximate the solution of the ARE equation later.Let us define the following state and action based Q functionQ∗(x(k),u(k))=V(x(k))(12) The optimal control problem described in(10)then becomes finding the optimal control policy u∗(k),which satisfies thefollowing time-varying temporal difference equation Q∗(x(k),u∗(k))=g(x(k),u∗(k))+Q∗(x(k+1),u∗(k+1))(13) III.A DAPTIVE O PTIMAL C ONTROL FOR T IME-V ARYINGD ISCRETE S YSTEMIn the following,we will show how to solve the tem-poral difference function(13)using a recursive time-varying least square method.The existing Q-function Q∗(x(k),u(k)) from k-th iteration to∞can be parameterized in the follow-ing formQ∗(x(k),u(k))=z T(k)H(k)z(k)=(z T(k)⊗z(k))vec(H(k))=(vec(H(k)))T(z(k)⊗z(k))(14) where z(k)=[x T(k)u T(k)]T,“vec(·)”is the matrix stretch,and“⊗”is the Kronecker product.Similarly,the cost function from(k+1)-th iteration to∞can be derived asQ∗(x(k+1),u(k+1))=z T(k+1)H(k+1)z(k+1)=(z T(k+1)⊗z T(k+1))vec(H(k+1))=(vec(H(k+1))T(z(k+1)⊗z(k+1))(15) If we defineˆz(k)=z T(k)⊗z T(k)andˆh(k)=vec(H(k)),then the temporal difference equation in Eq.(13)becomesˆh T(k)ˆz(k)=g(x(k),z(k))+ˆh T(k+1)ˆz(k+1)(16) During the sampling interval T,it can be assumed that ˆh(k)≈ˆh(k+1).Then,we have the following linear-in-parameter(LIP)formg(x(k),z(k))=ˆh T(k)(ˆz(k)−ˆz(k+1))=θT(k)φ(k)(17) whereθ(k)=ˆh(k)is the vector of system dynamic param-eter andφ(k)=ˆz(k)−ˆz(k+1)is the regressor vector.The above equation is important as it allows us to optimize over the current control policy by working backward in time.The defined Q function in(12)can be regarded as the desired target function that we need to approximate V∗(x(k))in the least square sense.In order to identify the time-varying parameterθ(k)=ˆh(k),recursive exponentially weighted recursive least squares(REWRLS)discussed in[24]is implemented in this paper.The REWRLS method is employed to optimize the following block-wise mean squared error(MSE)cost functionV(θ(k),k)=12ki=1λk−i(g(x(k),z(k))−θT(k)φ(k))(18)whereλis the forgetting factor that satisfies0<λ<1.A rule of thumb to chooseλis thatλwith smaller values puts greater emphasis on the recent data.The parameterθ(k) which minimizes Eq.(18)is given recursively byˆθ(k+1)=ˆθ(k)+K(k+1)(y(k+1)−φT(k+1)ˆθ(k))(19) where K(k)is the estimation gain matrix withK(k+1)=W(k+1)φ(k+1)=W(k)φ(k+1)(λI+φT W(k)φ(k+1))−1 W(k+1)=(I−K(k+1)φT(k))W(k)λ(20) and W(k)is the covariance matrix at time instant k.To avoid W(k)becoming too close to singularity,the covariance matrix is reset as followsW(k)=ρ0I,ifλmin≤ρ1(21) whereρ0andρ1are positive scalars.The following persistent excitation condition needs to be met to ensure the parameter convergence[25],[26]δ1I≤1λλi=1φi−1φT i−1≤δ0I(22)whereδ1≤δ0,andδ0andδ1are positive scalars.Therefore, the exploration noise is added in the following input during the parameter adaptationu e(k)=−K(k)x(k)+e(k)(23)682013I EEE C onference on C ybernetics and Intelligent Systems(C IS)where e (0,σ2)is the zero-mean white noise.IV.S IMULATIONSIn this section,two kinds of time-varying systems are con-sidered to testify the effectiveness of the proposed method.In the first case,the plant model is considered as a linear time-invariant system which experiences sudden model parameter shift during the operation.In the second case,a typical LDTV system is selected.These two systems can represent a large variety of LDTV systems in real applications.The sampling time is selected as T =0.001s and the weight matrices in (6)are given by S =[20;02],R =1.As the plant model is known in the simulation,the exact optimal feedback gains can be obtained by solving the DARE in (4)which is referred to as “LQR”,and compared with the proposed method which is referred to as “Proposed”.It is necessary to emphasize that the plant dynamics are only available in the simulation and they are not used in the proposed method.A.System with A Sudden Model ShiftIn the first case,the plant is initially given byx (k +1)= 01−0.15−0.2 x (k )+ 00.2u (k )(24)but for t ≥2,the plant parameters suddenly change so thatthe plant model is given byx (k +1)= 00.3−0.26−0.6 x (k )+ 00.4u (k )(25)The simulation results are shown in Figs.1,2,3,4,and5.In Fig.1,the control gains using the proposed methods and the desired control gains using LQR are shown and compared.It is found that the obtained optimal control gains using the proposed methods can accurately track the desired ones with LQR.More details can be found in Fig.2,where the convergence of the H parameters is shown.Fig.3demonstrates the state trajectories of the adaptive optimal control at the initial stage when the initial values are selected as x (1)=2and x (2)=−1.The control input and cost-to-go function are shown in Figs.4and 5,respectively.These simulation results show that the system can be robustly stabilized using the proposed method even subject to sudden parameter change.Fig.1.Desired control gains and actual control gainsFig.2.Convergence of HFig.3.States trajectories2013I EEE C onference on C ybernetics and Intelligent Systems (C IS )69Fig.4.Control inputFig.5.Cost-to-goB.General LDTV SystemIn this subsection,the plant is assumed to be a general LDTV system which is described by the following state space modelx (k +1)= 01−0.2sin (1.2t )−0.4cos (3t )x (k )+0.2e −0.01t u (k )(26)The initial conditions are the same as in the previous subsection and simulation results are shown in Figs.6,7,8,9,and 10.Descriptions of the simulation results are similar to the previous section and thus are omitted.From the simulation results,we can conclude that smooth optimal control performance for the general LDTV system can be guaranteed using the proposed method.Fig.6.Desired control gains and actual control gainsFig.7.Convergence of HFig.8.States trajectories702013I EEE C onference on C ybernetics and Intelligent Systems (C IS )Fig.9.Control inputFig.10.Cost-to-goV.C ONCLUSIONIn this paper,an adaptive optimal control has been de-veloped for unknown time-varying discrete-time systems. Instead of traditional Q-learning for time-invariant systems, we have considered the time-varying nature of the system dynamics.A modified temporal difference equation has been employed and solved using REWRLS without requiring any information of system dynamics.The simulation for two typical types of time-varying systems has verified the feasibility of the proposed method.R EFERENCES[1]V.Boltyanskiy,R.Gamkrelidze,Y.Mishchenko,and L.Pontryagin,The Mathematical theory of optimal processes.Wiley New York,1962.[2]J.Willems,“Least squares stationary optimal control and the algebraicriccati equation,”I EEE Transactions on Automatic C ontrol,vol.16, no.6,pp.621–634,1971.[3]R.Bellman and R.E.Kalaba,Dynamic programming and moderncontrol theory.Academic Press New York,1965.[4]S.S.Ge,C.Yang,S.-L.Dai,Z.Jiao,and T.H.Lee,“Robust adaptivecontrol of a class of nonlinear strict-feedback discrete-time systems with exact output tracking,”Automatica,vol.45,no.11,pp.2537–2545,2009.[5]P.J.Werbos,“A menu of designs for reinforcement learning overtime,”Neural Networks for C ontrol,pp.67–95,1990.[6]P.J.Werbos,“Consistency of hdp applied to a simple reinforcementlearning problem,”Neural Networks,vol.3,no.2,pp.179–189,1990.[7]P.J.Werbos,Handbook of Intelligent C ontrol:Neural,Fuzzy,andAdaptive Approaches,vol.15.1992.[8] D.Bertsekas,Dynamic Programming and Optimal C ontrol,vol.1.Athena Scientific Belmont,MA,1995.[9]P.J.Werbos,“Intelligence in the brain:A theory of how it works andhow to build it,”Neural Networks,vol.22,no.3,pp.200–212,2009.G.G.Lendaris,“Adaptive dynamic programming approach toexperience-based systems identification and control,”Neural networks, vol.22,no.5,p.822,2009.G.G.Lendaris,“Higher level application of adp:A next phase for thecontrolfield?,”I EEE Transactions on Systems,Man,and C ybernetics, Part B:C ybernetics,vol.38,no.4,pp.901–912,2008.F.-Y.Wang,H.Zhang,and D.Liu,“Adaptive dynamic programming:an introduction,”C omputational Intelligence Magazine,vol.4,no.2, pp.39–47,2009.F.L.Lewis and D.Vrabie,“Reinforcement learning and adaptivedynamic programming for feedback control,”C ircuits and Systems Magazine,vol.9,no.3,pp.32–50,2009.[14]R.W.Beard,Improving the closed-loop performance of nonlinearsystems.PhD thesis,Rensselaer Polytech.Inst.,Troy,NY,1995.W.Qiao,R.G.Harley,and G.K.Venayagamoorthy,“Coordinated reactive power control of a large wind farm and a statcom using heuris-tic dynamic programming,”I EEE Transactions on E nergy C onversion, vol.24,no.2,pp.493–503,2009.Y.Zhao,S. D.Patek,and P. A.Beling,“Decentralized bayesian search using approximate dynamic programming methods,”I EEE Transactions on Systems,Man,and C ybernetics,Part B:C ybernetics, vol.38,no.4,pp.970–975,2008.G.K.Venayagamoorthy,R.G.Harley,and D.C.Wunsch,“Com-parison of heuristic dynamic programming and dual heuristic pro-gramming adaptive critics for neurocontrol of a turbogenerator,”I EEE Transactions on Neural Networks,vol.13,no.3,pp.764–773,2002.G.K.Venayagamoorthy,R.G.Harley,and D.C.Wunsch,“Dualheuristic programming excitation neurocontrol for generators in a mul-timachine power system,”I EEE Transactions on Industry Applications, vol.39,no.2,pp.382–394,2003.C.Watkins,“Learning from delayed rewards,”C ambridge University,C ambridge,E ngland,Doctoral thesis,1989.A.G.Barto,R.S.Sutton,and C.J.Watkins,“Learning and sequen-tial decision making,”in Learning and computational neuroscience, Citeseer,1989.A.Al-Tamimi,F.Lewis,and M.Abu-Khalaf,“Model-free q-learningdesigns for linear discrete-time zero-sum games with application to h-infinity control,”Automatica,vol.43,no.3,pp.473–481,2007. [22]S.G.Khan,G.Herrmann,F.L.Lewis,T.Pipe,and C.Melhuish,“A novel q-learning based adaptive optimal controller implementation for a humanoid robotic arm,”in World C ongress,vol.18,pp.13528–13533,2011.[23]H.Zhang,F.L.Lewis,and A.Das,“Optimal design for synchro-nization of cooperative systems:state feedback,observer and output feedback,”I EEE Transactions on Automatic C ontrol,vol.56,no.8, pp.1948–1952,2011.[24]K.J.Astrom and B.Wittenmark,Adaptive C ontrol.Reading,Mass:Addison-Wesley,1989.[25]S.S.Ge,“Adaptive controller design forflexible joint manipulators,”Automatica,vol.32,no.2,pp.273–278,1996.[26]T.Zhang,S.S.Ge,C.Hang,and T.Chai,“Adaptive control offirst-order systems with nonlinear parameterization,”I EEE Transactions on Automatic C ontrol,vol.45,no.8,pp.1512–1516,2000.2013I EEE C onference on C ybernetics and Intelligent Systems(C IS)71。
诺瓦科技无线LED控制卡LED多媒体播放器TB6详细参数说明书
诺瓦科技无线LED控制卡LED多媒体播放器TB6详细参数说明书Taurus SeriesMultimedia PlayersTB6Specifications Doc u ment Version:V1.3.2Doc u ment Number:NS120100361Table of Contents Table of Contents (ii)1 Overview (1)1.1 Introduction ..................................................................................................................................................1 1.2Application (1)2 Features (3)2.1 Synchronization mechanism for multi-screenplaying (3)2.2 Powerful Processing Capability (3)2.3 Omnidirectional Control Plan (3)2.4 Synchronous and AsynchronousDual-Mode (4)2.5 Dual-Wi-Fi Mode ..........................................................................................................................................4 2.5.1 Wi-Fi APMode (5)2.5.2 Wi-Fi Sta Mode (5)2.5.3 Wi-Fi AP+Sta Mode (5)2.6 Redundant Backup (6)3 Hardware Structure (7)3.1 Appearance (7)3.1.1 Front Panel ...............................................................................................................................................7 3.1.2 RearPanel (8)3.2 Dimensions (9)4 Software Structure (10)4.1 System Software (10)4.2 Related Configuration Software (10)5 Product Specifications (11)6 Audio and Video Decoder Specifications (13)6.1 Image .........................................................................................................................................................136.1.1 Decoder ..................................................................................................................................................13Taurus Series Multimedia PlayersTB6 Specifications6.1.2 Encoder (13)6.2 Audio (14)6.2.1 Decoder (14)6.2.2 Encoder (14)www.novastar.tech ii Table of Contents6.3 Video (15)6.3.1 Decoder (15)6.3.2 Encoder ..................................................................................................................................................16iii1 Overview1 Overview 1.1 IntroductionTaurus series products are NovaStar'ssecond generation of multimedia playersdedicated to small and medium-sizedfull-color LED displays.TB6 of the Taurus series products(hereinafter referred to as “TB6”) featurefollowing advantages, better satisfyingusers’ requirements:●Loading capacity up to 1,300,000 pixels●Synchronization mechanism formulti-screen playing●Powerful processing capability●Omnidirectional control plan●Synchronous and asynchronousdual-mode●Dual-Wi-Fi mode ●Redundant backupNote:If the user has a high demand onmodule is recommended. For details,please consult our technical staff.In addition to solution publishing andscreen control via PC, mobile phones andLAN, the omnidirectional control plan alsosupports remote centralized publishingand monitoring.1.2 ApplicationTaurus series products can be widelyused in LED commercial display field,such as bar screen, chain store screen,advertising machine, mirror screen, retailstore screen, door head screen, on boardscreen and the screen requiring no PC.Classification of Taurus’application cases is shown in1 Overview2 Features 2.1 Synchronization mechanism for multi-screen playingThe TB6 support switching on/off functionof synchronous display.When synchronous display is enabled, thesame content can be played on differentdisplays synchronously if the time ofdifferent TB6 units are synchronous withone another and the same solution isbeing played.2.2 Powerful Processing CapabilityThe TB6 features powerful hardwareprocessing capability:● 1.5 GHz eight-core processor●Support for H.265 4K high-definitionvideo hardware decoding playback●Support for 1080P video hardwaredecoding● 2 GB operating memory●8 GB on-board internal storage spacewith 4 GB available for users 2.3 Omnidirectional Control PlanCluster control plan is a new internetcontrol plan featuring followingadvantages:●More efficient: Use the cloud servicemode to process services through auniform platform. For example, VNNOXis used to edit and publish solutions,and NovaiCare is used to centrallymonitor display status.●More reliable: Ensure the reliabilitybased on active and standby disasterrecovery mechanism and data backupmechanism of the server.●More safe: Ensure the system safetythrough channel encryption, datafingerprint and permissionmanagement.●Easier to use: VNNOX and NovaiCarecan be accessed through Web. As longas there is internet, operation can beperformed anytime and anywhere.●More effective: This mode is moresuitable for the commercial mode ofadvertising industry and digital signageindustry, and makes informationspreading more effective.www.novastar.tech 92.4 Synchronous and Asynchronous Dual-ModeThe TB6 supports synchronous andasynchronous dual-mode, allowing moreapplication cases and being user-friendly.When internal video source is applied, theTB6 is in asynchronous mode; whenHDMI-input video source is used, the TB6is in synchronous mode. Content can bescaled and displayed to fit the screen sizeautomatically in synchronous mode.Users can manually and timely switchbetween synchronous and asynchronousmodes, as well as set HDMI priority.2.5 Dual-Wi-Fi ModeThe TB6 have permanent Wi-Fi AP andsupport the Wi-Fi Sta mode, carryingadvantages as shown below:●Completely cover Wi-Fi connectionscene. The TB6 can be connected tothrough self-carried Wi-Fi AP or theexternal router.●Completely cover client terminals.Mobile phone, Pad and PC can be usedto log in TB6 through wireless network.Require no wiring. Display management can be managed at any time, having improvements in efficiency.TB6’s Wi -Fi AP signal strength is relatedto the transmit distance and environment.Users can change the Wi-Fi antenna asrequired.2.5.1 Wi-Fi AP ModeUsers connect the Wi-Fi AP of a TB6 to “12345678”.Configure an external router for a TB6 and users can access the TB6 by connectingthe external router. If an external router is configured for multiple TB6 units, a LAN canbe created. Users can access any of the TB6 via the LAN.www.novastar.tech 11directly access the TB6. The SSID is “AP+ the last 8 digits of the SN”, for example,“AP10000033”, and the default passwordis2.5.2 Wi-Fi Sta Mode2.5.3 Wi-Fi AP+Sta ModeIn Wi-Fi AP+ Sta connection mode, userscan either directly access the TB6 oraccess internet through bridging connection. Upon the cluster solution, VNNOX and NovaiCare can realize remote solution publishing and remotemonitoring respectively through theInternet.2.6Redundant BackupTB6 support network redundant backup and Ethernet port redundant backup.●Network redundant backup: The TB6 automatically selects internet connectionmode among wired network or Wi-Fi Sta network according to the priority.●Ethernet port redundant backup: The TB6 enhances connection reliabilitythrough active and standby redundant mechanism for the Ethernet port used toconnect with the receiving card.www.novastar.tech 13Taurus Series Multimedia PlayersTB6 Specifications 3Hardware Structure3 Hardware Structure 3.1 AppearanceSYSSystem status indicator●Flashing once every other 2seconds: The system isoperating normally.●Flashing once every othersecond: The system isinstalling the upgradepackage.●Flashing once every other0.5 second: The system isdownloading data from theInternet or copying theupgrade package.●Always on/off: The system isoperating abnormally. CLOUD Internet connection statusindicator●Always on: The unit isconnected to the Internetand the connection status isnormal.●Flashing once every other 2seconds: The unit isconnected to VNNOX andthe connection status isnormal.RUN FPGA status indicatorSame as the signal indicator3.1.1FrontPanelHardware Structure Name Descriptionstatus of the sending card:FPGA is operating normally.Figure 3-1 Front panel of the TB6Note: All product pictures shown in this document are for illustration purpose only.Actual product may vary.Table 3-1 Description of TB6 front panelSWITCH Button for switching betweensynchronous andasynchronous modes●Always on: Synchronousmode●Off: Asynchronous mode Figure 3-2 Rear panel of the TB6Name DescriptionTEMP Temperature sensor port LIGHT Light sensor portWiFi-AP Wi-Fi AP antenna port WiFi-STA Wi-Fi Sta antenna port COM1 ReservedCOM2 ReservedETHERNETGigabitEthernet portIndicatorstatus:●Yellow indicator alwayson: The unit isconnected to 100MEthernet cable and thestatus is normal.● Green and yellow indicators always on at the same time: The unitis connected to GigabitEthernet cable and thestatus is normal.USB USB 2.0 portHDMI ● IN: HDMI 1.4 input●OUT: HDMI 1.4 outputAUDIO OUT Audio outputRESET Factory reset buttonPress and hold the buttonfor 5 seconds to reset theunit to factory settings. Note: All product pictures shown in this document are for illustration purpose only. Actual product may vary.Table 3-2 Description of TB6 rear panelHardware StructureName DescriptionLED OUT Output Ethernet port ON/OFF Power switch100-240V~,50/60Hz Power inputUnit: mm4 Software Structure4 Software Structure 4.1 System Software● And r o i d o pe rating system software● Android terminal application software ●FPGA program Note: The third-party applications are not supported.4.2 Related Configuration SoftwareTable 4-1 Related configuration softwareViPlex Express PC client software of the TB6 only includes Windows which is mainly used for screen management, editing, and solution publishing.Display screen configuration software works in Windows only, and is used to adjust screens to the best display status. NovaLCT5 Product Specifications 5 Product Specificationspower consumptio nStorage Space Operatingmemory2 GBInternalstoragespace8 GBon-board with 4GB availableStorage Environmen tTemperature 0°C–50°C Humidity 0% RH–80%RHOperating Environmen t Temperature -40°C–80°C Humidity 0% RH–80%RH375 mm × 280mm × 108 mmfor usersPackinginformationDimensions (H×W×D)5 Product Specifications●2 USB ports allows forplayback of media importedfrom USB drives.●1 Onboard brightness sensorport supports automatic andscheduled smart brightnessadjustment.Antenna6Image Size48×48pixels~8176×8176pixel sNoAudio and Video Decoder 6.1.2 EncoderTyp e CodecSupportedImage SizeMaximumData RateFileFormatRemarksJP EG JPEGBasel96×32pixels~817690Mpixels/SecondJFIFfileN/A nGIF GIF NoRestrictionGIF N/APNG PNG NoRestrictionPNG N/AWEB P WEBP NoRestrictionWEBP N/ASpecifications6.1Image6.1.1Decoder 28ine ×8176 pixels format1.02 6.2 AudioType Codec Channel Bit rate SamplingrateFileFormatRemarksMPE G MPEG1/2/2.5AudioLayer1/2/32 8kbps~320Kbps, CBRand VBR8KHZ~48KHzMP1,MP2,MP3N/AWind ows Medi a Audi o WMAVersion4,4.1, 7, 8,9,wmapro2 8kbps~320Kb ps8KHZ~48KHzWMANon-supportWMAPro,lossless andMBRWAV MS-ADPCM,IMA-ADPCM,PCM 2 N/A 8KHZ~48KHzSupport4bitMS-ADPCM,IMA-ADWAV 29PCMOGG Q1~Q10 2 N/A 8KHZ~48KHz OGG,OGAN/AFLAC Compress Level0~8 2 N/A FLACN/AAAC ADIF,ATDSHeaderAAC-LCandAAC-HE,AAC-ELD 5.1 8KHZ~48KHzAAC,M4AN/AAMR AMR-NB,AMR-WBAMR-NB4.75~12.2kbps@8kHzAMR-WB6.60~23.8KHZ,16KHz3GP N/A8K HZ~48KHzN/A1 30 35Gand YUV400(monochrome) is also supported for H.264.Type Codec SupportedImage SizeMaximumFrameRateMaximumBitRate(IdealCase)RemarksH.264/ AVC H.264144×96pixels~1920×1088 pixels30fps 20MbpsMOV,3GPNotsupportMBAFFGoogl e VP8 VP8 96×96pixels~1920×1088 pixels30fps WEBMN/AFile Format10M bps 36。
HJB方程在最优投资策略中的应用
万方数据
problem without constraint, then the method of dynamic programming can be used to solve this problem.Finally, we make the numerical analysis. In chapter five, we summarize the main results of this article, the inadequate and the direction of future research . Key Words: option, proportional reinsurance, CEV process, credit risk bond, Lagrange duality theorem, HJB equation.
p2p小额贷款的理念起源于1976但鉴于当时并没有互联网技术因此在该理念下的金融活动无论贷款规模从业者规模还是社会认知层面都比较局限?直到2005月英国人理查德杜瓦詹姆斯亚历山大萨拉马休斯和大卫尼克尔森4位年轻人共同成立了世界上第一家p2p贷款平台zopap2p贷款才被广泛传播
学校代码: 10270
III
万方数据
目 录
摘 要 ABSTRACT( 英文摘要) 目 录 1 第一章 前言 1.1 1.2 选题背景和意义 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 文献综述 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I II IV 1 1 3 6 6 6 8 9 9 9 13 16 20 21 21 21 26 27 31 32 33
双时间尺度系统最优控制设计方法的综述
2020年12月第27卷第12期控制工程Control Engineering of ChinaDec. 2020Vol.27, No. 12文章编号:1671-7848(2020)12-2226-08 DOI: 10.14107/ki.kzgc.20180699双时间尺度系统最优控制设计方法的综述钟珊珊ia,杨春雨ib,黄新利2(1.中国矿业大学a.电气与动力工程学院:b.信息与控制工程学院,江苏徐州221006; 2.酒泉卫星发射中心,甘肃酒泉735000)H摘要:双时间尺度系统最优控制设计方法是近年来的研究热点。
本文对双时间尺度系统 最优控制的设计方法、双时间尺度系统的特性分析、双时间尺度系统最优控制问题相关应用等方面进行了全面的梳理。
首先,给出双时间尺度系统最优控制问题的数学模型,并分析相关研究的关键难点;其次,分别给出基于糢型和数据驱动的双时间尺度系统最优控制设计方法:然后,综述双时间尺度系统稳定性和次优性分析方法;接下来,概述了双时间尺度系统最优控制方法的应用案例;最后,展望双时间尺度系统最优控制的研究方向。
关键词:双时间尺度系统;奇异摄动理论;最优控制;穗定性;次优性中图分类号:T P13 文献标识码:AAn Overview on the Design Method for Optimal Control ofTwo-time-scale SystemsZHONG Shan-shan x\YANG Chun-yu xb,HUANGXin-li2(1. a. School o f Electrical and Power Engineering; b. School o f Information and Control Engineering, China University of Miningand Technology, Xuzhou 221006, China; 2. Jiuqan Satellite Launch Center, Jiuquan 73500, China)Abstract: The design method of optimal control for two-time-scale systems i s a research hotspot in recent years. In t h i s paper,the design method for optimal control of two-time-scale systems,characteristic analysis of two-time-scale systems and related application of optimal control for two-time-scale systems are reviewed. Firstly, the mathematical model and challenges for optimal control problem of two-time-scale systems are given. Secondly, the model based and data-driven design methods for optimal control of two-time-scale systems are presented respectively.Then,the analysis methods for st a b i l i t y and sub-optimality of the two-time-scale systems are presented. Next, the typical application cases of optimal control of two-time-scale systems are summarized. Finally, the future research directions for optimal control of two-time-scale systems are prospected.Key words:T w o-time-scale systems;singularly perturbed theory;optimal control;stab ility;sub-optimalityi引言在航空航天、电力、化工和机械等工程领域的 控制系统设计中,大量研宄对象具有显著的双时间 尺度特性。
电气工程与自动化专业英语 第13章
Chapter 13: Adaptive Control and Predictive Control
Adaptive Control and Predictive Control
Before introduction to the advanced control design techniques, we present a brief overview of control techniques and paradigms: The 1950s gave rise to the state-space formulation of differential equations The method of dynamic programming was developed by Bellman (1957) The maximum principle was discussed by Pontryagin (1962).
2
Adaptive Control and Predictive Control
Kalman demonstrated that when the system dynamic equations are linear and the performance criterion is quadratic (LQ control) Produced linear-quadratic-Gaussian (LQG) control. the concept of the H- norm and -synthesis theory. Artificial Neural Network for control and Fuzzy Control are the typical AI control design techniques.
水轮机电液调节系统及装置技术规程(英文版)
水轮机电液调节系统及装置技术规程(英文版)以下是为您生成的二十个关于水轮机电液调节系统及装置技术规程相关的英语释义、短语、单词、用法及双语例句:---1. **“水轮机电液调节系统”**:Hydroelectric turbine electro-hydraulic regulating system- 释义:用于控制水轮机运行的电液结合的调节系统- 短语:optimize the hydroelectric turbine electro-hydraulic regulating system(优化水轮机电液调节系统)- 单词:hydroelectric(水电的)、turbine(涡轮机、水轮机)、electro-hydraulic(电液的)、regulating(调节)- 用法:This paper focuses on the performance of the hydroelectric turbine electro-hydraulic regulating system.(这篇论文关注水轮机电液调节系统的性能。
)- 双语例句:The stability of the hydroelectric turbine electro-hydraulic regulating system is crucial for efficient power generation.(水轮机电液调节系统的稳定性对于高效发电至关重要。
)2. **“装置”**:Device / Installation- 释义:设备、仪器;安装、设置- 短语:testing device(测试装置)、installation procedure(装置安装程序)- 单词:test(测试)、procedure(程序、步骤)- 用法:The new device has improved the efficiency of the system.(新装置提高了系统的效率。
最优控制模型
H
曲线1
曲线2
曲线3 0 b c
6.2.2 吃糕控制问题
• 1、问题 • 假设行为人拥有一些不可再生的资源,如一块 蛋糕s,该资源的初始存量为s0,行为人在时刻 t的消费量为c(t),消费的效用函数为u(c)。又假 设行为人的规划期从0时到T时,时期长度固定, 其未来效用的折现率为固定折现率ρ,且行为 人要在T时期末将此蛋糕消费完,不留遗产。 问题是,该行为人如何在0到T的整个时期内分 配此蛋糕的消费量,以使其获得的效用最大?
6.1 离散跨期选择问题
• 1、离散跨期选择的经典问题——“吃糕”问题 • 假设行为人拥有一些不可再生的资源,如一块 蛋糕,该资源的初始存量为S0,行为人在时期t 的消费量为ct,则在时期t资源的存量为: St=St-1-ct 再假设行为人确切地知道他能活3个时期,如 青年、中年、老年三个时期,问题是该行为人 如何将其资源在各个时期中消费?
6.2 连续时间的最优控制
• 4、状态变量的运动方程 • 状态变量就是不由行为人直接控制的系统内生决 定的变量,而控制变量则是行为人可直接控制的 变量。行为人通过对控制变量的控制可以间接地 影响状态变量,状态变量的变化方程是控制变量 的函数,可表示为: ś(t)=g[s(t),c(t),t] 称为状态变量的运动方程。最优控制问题就是要 找出控制变量在各个时刻的最优取值,使得目标 函数值达到最大(或最小)。控制变量从初始时 刻到终结时刻的变化过程称为控制变量的路径, 状态变量的变化过程称为状态变量的路径。
6.2 连续时间的最优控制
• 1、跨期效用函数 • 如此设定的跨期效用函数具有可加性 (additivity)或称可分离性(separability)的性 质。 • 可分离性的条件为: Mij/ck=0 其中Mij为不同时期消费的边际替代率 (marginal rate of substitution between consumption in period i and j),即: Mij=Ui(.)/Uj(.)=(U/ci)/(U/cj)
智能控制决策与优化 英语
智能控制决策与优化英语The topic of "Intelligent Control, Decision, and Optimization" encompasses a wide range of concepts and applications in the field of engineering and technology. It involves the use of advanced algorithms, artificial intelligence, and machine learning techniques to develop control systems that can make decisions and optimize performance in complex and dynamic environments.Intelligent control refers to the use of intelligent algorithms and systems to control the behavior of dynamic systems. This can include the use of neural networks, fuzzy logic, and evolutionary algorithms to design controllers that can adapt and learn from their environment. These intelligent control systems are often used in applications such as robotics, autonomous vehicles, and industrial automation.Decision-making in the context of intelligent control involves developing algorithms and models that can makeoptimal decisions in real-time based on available information and objectives. This can include techniques such as reinforcement learning, deep learning, and predictive modeling to make decisions that maximize performance or achieve specific goals.Optimization, on the other hand, focuses on the development of algorithms and methods to find the best possible solution from a set of alternatives. In the context of intelligent control, optimization techniques are used to fine-tune control parameters, design optimal trajectories, or maximize the efficiency of a system.Overall, the integration of intelligent control, decision-making, and optimization techniques has the potential to revolutionize the way we design and operate complex systems. By leveraging advanced algorithms and machine learning, we can create control systems that are more adaptive, efficient, and robust in a wide range of applications. This has the potential to drive innovation and improve the performance of various technologies,ultimately leading to more intelligent and autonomous systems.。
考虑能见度影响的公路隧道照明动态优化与智能控制
第40卷第10期2023年10月控制理论与应用Control Theory&ApplicationsV ol.40No.10Oct.2023考虑能见度影响的公路隧道照明动态优化与智能控制梁波1,2,牛佳安1†,李硕1,杨彦斌1,肖靖航1,张晓坚1(1.重庆交通大学土木工程学院,重庆400074;2.重庆交通大学山区桥梁与隧道工程国家重点实验室,重庆400074)摘要:为解决不同能见度影响下公路隧道实际路面亮度变化过大以及由此引起的行车安全与能源虚耗问题,本文提出了一种能够改善公路隧道照明环境的动态优化与智能控制方法.首先,通过对不同时空条件下的公路隧道进行现场试验和数据分析,得到了隧道内能见度的变化规律;其次,在公路隧道传统照明设计的基础上考虑能见度对照明环境的影响,建立了基于隧道内能见度、交通量、车速、路面亮度和照明亮度的按需照明与动态优化模型;随后,以不同地区公路隧道的实测数据为样本,结合划分出的公路隧道典型照明场景和模糊径向基神经网络算法构建了公路隧道照明智能控制模型,最后,通过仿真实验验证了所构建模型的有效性,其结果表明,本文所提出的优化控制方法能够在保证隧道照明安全性的前提下兼顾节能性.关键词:照明优化控制;模糊径向基神经网络;能见度;照明环境改善;仿真模拟引用格式:梁波,牛佳安,李硕,等.考虑能见度影响的公路隧道照明动态优化与智能控制.控制理论与应用,2023, 40(10):1783–1792DOI:10.7641/CTA.2022.20042Dynamic optimization and intelligent control of highway tunnel lightingconsidering visibility effectsLIANG Bo1,2,NIU Jia-an1†,LI Shuo1,YANG Yan-bin1,XIAO Jing-hang1,ZHANG Xiao-jian1(1.School of Civil Engineering,Chongqing Jiaotong University,Chongqing400074,China;2.State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing400074,China)Abstract:To solve the problem of excessive changes in the road surface luminance under different visibility levels and the consequent traffic safety and energy wastage,a dynamic optimization and intelligent control method that can improve the lighting environment of highway tunnel is proposed in this paper.Firstly,throughfield tests and data analysis of highway tunnels under different space-time conditions,the variation of visibility in tunnels is obtained.Secondly,the influence of visibility on the lighting environment is considered on the basis of the traditional lighting design of highway tunnels.And an on-demand lighting and dynamic optimization model based on visibility,traffic volume,vehicle speed,road surface luminance and lighting luminance is established.Subsequently,the measured data of highway tunnels in different regions are used as bining the typical lighting scenes of highway tunnels and fuzzy radial basis neural network algorithm to build a highway tunnel lighting intelligent control model.Finally,the effectiveness of the model is shown by simulation experiments.The results show that the proposed optimal control method can take into account energy saving on the premise of ensuring the safety of tunnel lighting.Key words:lighting optimization control;fuzzy radial basis function neural networks;visibility;lighting environment improvement;simulationCitation:LIANG Bo,NIU Jiaan,LI Shuo,et al.Dynamic optimization and intelligent control of highway tunnel lighting considering visibility effects.Control Theory&Applications,2023,40(10):1783–17921引言公路隧道作为交通运输环节中的重要节点,具有克服地形障碍同时提高交通运输效率的优势,因此广泛应用于山区高速公路中[1].伴随着公路隧道数量的激增,传统隧道照明设计所选取的照明环境影响因素不足,未考虑影响参数的动态变化,且照明控制方法较为落后等问题也愈发严峻,不仅会导致大量能源损耗,还极大地威胁着公路隧道内的行车安全[2].因此,收稿日期:2022−01−14;录用日期:2022−07−02.†通信作者.E-mail:ja***********.本文责任编委:王卓.国家自然科学基金项目(51878107),重庆市人才团队项目(2019–9–95),重庆市研究生科研创新项目(2022B0004)资助.Supported by the National Natural Science Foundation of China(51878107),the Project of Chongqing Talent Team(2019–9–95)and the Research and Innovation Program for Graduate Students in Chongqing(2022B0004).1784控制理论与应用第40卷研究一种兼具安全性和节能性的公路隧道照明动态优化与智能控制方法,对隧道长期稳定运营具有重要意义[3].近年来,大量学者针对隧道照明环境影响因素进行了深入研究,但大都集中于隧道交通量、车速和洞外亮度等[4–6]方面,鲜有学者在设计照明参数时考虑隧道内能见度对照明环境的影响.周豫菡等[7]研究表明隧道内能见度与隧道照明有关,并提议通过烟雾的光线透过率这一指标间接衡量能见度.董丽丽等[8]通过研究低透过率下隧道照明亮度对能见度的影响,发现照明亮度与能见度存在非线性关系.Mehri等[9]指出隧道内部的主要视觉问题是照明灯具的光线被汽车尾气排放造成的烟雾吸收和扩散,从而降低了隧道能见度.Zhang和Gao等[10]通过研究大雾天气下驾驶员的视认行为,发现目标识别距离和视觉搜索范围随能见度的降低而急剧缩小.可以看出,上述研究均是对数据间的变化规律进行探究,缺少进一步对隧道能见度与照明亮度之间的关系进行定量化分析,且未能利用所得成果指导照明的优化与控制.改善公路隧道照明环境使其更具安全性和节能性,一直以来都是各国科研人员研究的重点.目前,对公路隧道照明环境改善方法的研究主要集中在灯具优化布置、照明亮度调整、照明控制方式等方面,其中,灯具优化布置是一种通过改变灯具的类型[11]、配光曲线[12]以及布置参数[13],使其更加符合照明需求的照明环境改善方法.此类隧道照明环境改善方法的实现较为复杂,因此随着LED照明无极调光技术的发展逐渐淡出大众视野.调整照明亮度是一种通过构建优化模型[14]或仿真模拟[15],实现照明亮度/照度最优化的照明环境改善方法.此类方法相比于灯具优化布置,因其具备易实现的特点故在隧道中使用较多.通过照明控制方式改善公路隧道照明环境可以分为“硬件改善”和“软件改善”.“硬件改善”是指照明控制电路、模块以及流程的改进[16],如利用STM32F103系列芯片[17]和KNX总线[18]对控制系统进行升级改造,或者直接提出新的控制线路[19].但目前照明控制硬件系统趋于完善,存在改善效果不明显以及改造工期长、成本高等问题.为此,近年来包括遗传算法[20]、模糊控制[21]、人工神经网络[22]在内的相关智能算法逐渐得以应用,这些“软件改善”方法流程简明,不需要改变隧道现有照明硬件设施,在公路隧道照明控制方面具有较大的优势.但随着智能控制算法的逐渐普及,各控制方法自身不足所带来的问题愈发凸显,因此本文将现有方法的主要局限性总结为以下两方面:一是考虑控制参数不全面,目前隧道照明的优化控制方法并未考虑能见度及其动态变化特性,故所得照明亮度易受实时能见度的影响,在隧道能见度较低时造成路面亮度过低,存在安全风险;在隧道能见度较高时造成路面亮度过高,产生能源虚耗.二是控制目标未优化,当前公路隧道照明的控制方法仅用于对灯具的调光控制,未考虑控制目标即亮度参数本身是否需要进行优化,仅注重于控制目标的响应,故智能化程度较低.针对上述问题,本文以保证隧道内的行车安全、提高照明控制的智能化程度为目标,充分考虑实时能见度对路面亮度的影响,建立了能够动态调节照明亮度的优化模型;将优化模型与模糊系统理论和神经网络算法相融合,提出一种具有较强普适性的公路隧道照明动态优化与智能控制方法,旨在实现对不同能见度影响下隧道照明亮度的自适应控制,达到在任意照明场景下保持隧道路面亮度最佳的效果,进一步为公路隧道安全、节能照明的智能化实现提供解决思路.2照明优化控制参数的获取与分析通过综合分析公路隧道照明环境的影响因素、特点以及近年来大量学者的研究成果[4–22],确定以隧道内能见度、交通量、车速和路面亮度作为目标数据进行获取与分析.2.1试验隧道基本概况与现场测量方案为了减少外部条件的干扰并突出能见度对隧道照明场景的影响,本次试验的隧道选取重庆市巴南区的长冲隧道(图1).由于每日有大量运输砂石的卡车往返于该路段,加之隧道较长,沙尘与汽车尾气所形成的混合气体污染物无法及时排出隧道,除此以外重庆地区频发的“高速公路团雾”现象也会造成隧道内能见度严重下降[23].图1试验隧道位置与照明环境状况Fig.1Test tunnel location and lighting environmentconditions依次对隧道各照明区段能见度、交通量、车速以及路面亮度等照明环境影响因素进行测量计算.为保证试验精度,测量区段根据隧道各照明区段均匀布置,且各测量区段均布8个测点,测量结果取平均值.共测得2020年7月1日、5日、6日、10日、11日以及25日共6天的全天数据,按照晴天、阴天和雨天进行分组并求出每个时间段的平均值以消除测量误差影响.第10期梁波等:考虑能见度影响的公路隧道照明动态优化与智能控制17852.2照明控制区段确定经过现场测量获得的数据不仅数量庞大,而且分布在隧道各个照明区段,同时各数据影响程度不一且可能存在相互关系,这使得隧道照明优化的研究过于复杂,因此需要分析出照明优化的目标区段与对应的优化参数.通过分析各照明区段能见度的分布特征,确定在不同照明场景下最需要进行优化与控制的照明区段.由图2可知,公路隧道内能见度沿着行车方向总体分布规律为先减后增,于出入口段出现极大值,中间段出现极小值.隧道出入口段能见度水平比隧道内部平均高24%,且离散程度大,而隧道内部能见度水平离散程度低.究其原因,公路隧道出入口段与外部环境接壤,车辆行车带动自然风从而将烟尘带出隧道;而公路隧道中间段类似于半封闭结构,气体类污染物不能及时排出,故隧道内部视觉环境更差、易产生交通安全隐患[24].同时,根据文献[25]所述,当隧道照明亮度较低时(L<30cd/m 2),提高照明亮度能够极大的提升隧道能见度.由于隧道中间段的正常照明亮度较其他照明段更低,故增加中间段照明亮度对于改善隧道内能见度具有十分显著地效果.因此选择公路隧道中间照明段作为亮度优化的目标区段,并通过控制照明亮度的方式来改善隧道中间段的能见度,以此保证隧道内的行车安全.V IV I(b)阴天V I(c)雨天图2不同时空条件下公路隧道各照明区段能见度分布图Fig.2Visibility distribution in each lighting section of hig-hway tunnel under different space-time conditions2.3隧道内部能见度数据分析关于交通量、车速和照明亮度之间的关系已有众多学者进行过研究与阐述[17–21],故不再赘述且着重研究不同时间、空间下,隧道内路面亮度与能见度之间的变化规律.通过将隧道内路面亮度和能见度根据时序与天气情况进行分类排列,绘制隧道内能见度和路面亮度的变化折线图见图3.由图3可知,隧道内路面亮度在大部分晴天和阴天场景中都无法达到规范中的设计亮度值;隧道内能见度和路面亮度的变化规律大体呈现正相关关系;随着能见度水平的增加,隧道内路面亮度也呈增长趋势.究其原因,当能见度水平提高时,隧道内积聚的颗粒物和浑浊气体含量随之降低,因此阻碍照明灯具光线传播的环境介质较少,故隧道内路面亮度随之增大,而当能见度水平降低时则相反.同时,由不同场景下能见度的变化规律可以得出:夜晚的隧道能见度要明显大于白天;雨天情况下的隧道能见度要明显大于晴天和阴天.产生此种变化的主要原因是由于夜晚的交通量骤减,由车辆行驶所产生的尾气和扬尘现象减弱;同时雨天情况路面潮湿,也能较好的抑制扬尘.V I(a)晴天(b)阴天V I(c)雨天图3不同时空条件下隧道内路面亮度与能见度的相关关系Fig.3Correlation between road surface luminanceand visibility in the tunnel under different space-time conditions由图3易得在低能见度情况下,若仍按照《公路隧道照明设计细则》[26](JTGT D70/2–01–2014简称《照明细则》)进行传统照明设计,隧道内易出现低能见度和低可视亮度的行车环境,进而产生安全隐患.因此,需要研究一种能够动态优化照明亮度的方法.综上所述,隧道内部的照明优化应该在传统照明设计的基础上,考虑实时能见度、交通量和车速对隧道内亮度的影响,从而进行动态调控.3公路隧道内部照明动态优化方法研究3.1按需照明的亮度计算模型《照明细则》中表6.1.1虽然在设计隧道内照明亮度时考虑了理论设计交通量和车速的影响,但当隧道土建完成后设计亮度便为固定值,并未考虑交通量和车速是实时变化的.因而传统照明设计不能根据实际的交通流量和行车速度来调整亮度,这将导致照明能源的浪费.因此,需要基于传统照明设计建立能够根据实时交通量和车速进行动态调整的照明亮度计算模型.采用MATLAB 曲线拟合工具对《照明细则》中的规范设计亮度值进行多阶拟合,得到考虑节能性的中间段照明亮度计算模型如式(1)所示.L t al = L inH L inM L inL=al inH inM L inL 分别为隧道双向交通下的大流量(N 650veh/h)、中流量(180<N<650veh/h)和小流量(N 180veh/h)的亮度值(cd/m 2);v 为行车速度(km/h).该亮度计算模型能够依据实时交通量和车速对隧道内照明亮度进行动态调整,较传统照明设计更为合理.但由于没有考虑能见度对照明环境的影响,所以在能见度较低的情况下计算模型输出数值会偏低,无法满足安全行车需求.因此,需要基于能见度对计算模型进行改善.3.2照明亮度动态优化模型及方法由前文可知,公路隧道内能见度水平对灯具照明亮度的转换效率影响很大.对于不同的能见度环境,若采取相同照明条件会使得隧道内路面亮度无法达到设计值,这便埋下了安全隐患.因此,为了保证隧道内部照明环境在不同能见度条件下均能达到设计亮度值,探索隧道内路面亮度与能见度间的变化规律是十分重要的.对测得的隧道内实际路面亮度和能见度进行曲线拟合分析,得出的相关关系见图4和式(2).其中拟合曲线的决定系数为0.958,拟合计算模型的总体误差控制在5%以内.VI图4隧道内能见度、路面亮度和照明亮度损失率关系图Fig.4Fitted curve of visibility and road surface luminanceL f in =0.673ln(VI −0.335)+2.136,(2)式中L f in 为隧道中间段路面亮度拟合值(cd/m 2).从图第10期梁波等:考虑能见度影响的公路隧道照明动态优化与智能控制1787中曲线的变化趋势可以得出:随着隧道内能见度的不断提高,路面亮度的增长速率逐渐降低,当能见度提高到一定程度时,路面亮度值趋于平稳.将隧道内未受能见度影响的亮度值与受能见度影响后的亮度值之间的折减比例定义为照明亮度损失率,表达式如下:R lin =L bl−L f inL bl,(3)式中:R lin为隧道中间段照明亮度损失率;L bl为照明亮度损失前的亮度值(cd/m2).由式(2)可知,当公路隧道照明亮度不受能见度干扰时,试验隧道的亮度值L bl 为1.861cd/m2.因此,将式(3)整理可得照明亮度损失率与能见度的关系如式(4)所示.R lin=−0.361ln(VI−0.335)−0.148.(4)对图4进行分析可以得出,由于公路隧道内部积聚污染颗粒物和浑浊大气相互作用会阻碍照明光线的传播效率,进而使隧道内路面亮度无法达到照明亮度设计值,并且随着隧道内能见度的降低,照明亮度损失率也逐渐增大.如此低的亮度势必会影响驾驶员在隧道内的行车安全,存在重大安全隐患.因此,需要将由能见度不足而损失的亮度进行动态补偿,根据照明亮度损失率定义可得L cbl−(L t al−L f in)L cbl =R lin,(5)式中:L cbl为照明亮度补偿值(cd/m2);L t al为照明亮度损失后的亮度目标值(cd/m2).将式(4)代入式(5)中可得照明亮度补偿值与能见度的关系式为L cbl =L tal−0.673ln(VI−0.335)−2.1360.361ln(VI−0.335)+1.148.(6)由上式可以得到考虑安全性的隧道内照明亮度优化模型为L o=L bl+L tal−0.673ln(VI−0.335)−2.1360.361ln(VI−0.335)+1.148,(7)式中L o为隧道内照明亮度优化值(cd/m2).为了同时满足安全性和节能性的照明优化需求,将考虑节能性的照明亮度计算模型与考虑安全性的照明亮度优化模型相结合,提出隧道内照明动态优化方法.该方法首先通过公式(1)的节能照明亮度计算模型求得路面亮度目标值L tal,随后代入式(7)中进行安全性优化,最终得出兼备节能性与安全性的照明亮度优化值.4公路隧道照明智能控制方法研究上述隧道内照明动态优化方法能够综合考虑隧道内能见度、交通量、车速、路面亮度和照明亮度等多因素的影响,在传统照明设计的基础上,同时在节能与安全两方面实现了动态优化.然而,在实际操作中,照明亮度优化计算过程过于复杂且不涉及时间参数,无法满足照明实时优化的需求.为了简化计算过程,实现公路隧道照明的实时智能控制,引入能够高效依据优化方法处理多元参数间非线性关系的模糊神经网络来实现公路隧道照明智能控制.4.1公路隧道典型照明场景划分公路隧道照明环境是一个复杂的多元参数耦合场,各照明影响因素的之间相互作用,不利于实现公路隧道照明智能控制,因此需要构建公路隧道典型照明场景.公路隧道典型照明场景指的是由影响隧道照明效果的各类参数通过阈值划分后进行组合设计产生的基础工况,是建立公路隧道照明智能控制方法的前提和基础.因此,为了保证公路隧道照明智能控制的容错能力进而提高人机交互时的鲁棒性[27],采用模糊逻辑思想划分隧道内部照明场景影响因素区间.1)高斯隶属度函数.通过对实测数据的分析可知,交通量和车速数据呈现正态分布的特征,故应当根据现场实测交通量数据范围和《照明细则》的要求对参数区间进行细分.交通量场景区间划分为[0,350],(350,750],(750, 1200]和(1200,∞);车速场景区间划分为[0,40],(40, 60],(60,80]和(80,∞).为方便模糊神经网络的构建,将照明场景的区间按照模糊语言命名.交通量和车速的模糊语言变量为{零,正小,正中,正大},记为{ZO,PS,PM,PB},对应模糊集的隶属度函数采用高斯函数.2)三角隶属度函数.根据现场实测数据范围和《照明细则》,结合国际道路协会(PIARC)关于隧道内空气质量的技术报告[28],对公路隧道内能见度和亮度进行划分.能见度场景区间划分为[0,0.3],(0.3,0.5],(0.5,0.7],(0.7,0.9]和(0.9,1.0];隧道亮度场景区间划分为[0,1.0],(1.0, 1.5],(1.5,2.5],(2.5,4.5]和(4.5,10].根据查阅的相关规定和资料可知,当能见度低于0.3时,隧道行车危险且隐患大,隧道内应禁止行车并采取通风措施改善隧道内部环境;当能见度高于0.3时,可采取优化隧道内照明亮度的方式改善行车环境.能见度和照明亮度的模糊语言变量为{零,正小,正中小,正中大,正大},记为{ZO,PS,PMS,PMB,PB},对应模糊集的隶属度函数采用三角函数.将能见度、交通量和车速场景区间相互匹配,共计得出80个典型照明场景.通过结合能见度–亮度变化规律与《照明细则》设计经验,采用T-S型模糊推理系统将典型照明场景与亮度场景区间数值一一对应,形成80条模糊控制规则.4.2公路隧道照明智能控制算法由于公路隧道典型照明场景影响因素之间的关系呈现出复杂的非线性特点,并且智能控制时需要实时1788控制理论与应用第40卷计算,如果仅利用模糊系统理论进行控制,则无法保证公路隧道照明智能控制的精度和效率.而神经网络不仅在挖掘数据信息中的非线性关系时表现优异而且具有并行结构,能够加快数据处理速度.因此,根据得到的公路隧道典型照明场景,将模糊系统理论与神经网络相融合,基于优化模型的逻辑规则形成公路隧道照明智能控制算法.公路隧道照明智能控制算法共有5层结构组成,其中第1层为数据输入层.它将输入向量x=(x1x2x3)T直接传送到下一层.其中:x1,x2,x3分别对应3个公路隧道内部照明场景影响因素.第2层为模糊化层,根据选取的隶属度函数,本层共有13个神经元.将对相应的输入参数模糊化,计算出输入数据对各个语言变量模糊集合的隶属度,隶属度表示为µij=x i−a ijb ij−a ij,a ij x i b ij, c ij−x ic ij−b ij,b ij x i c ij,i=1,j=1,2,3,4,(8)µij=exp(−(x i−c ij)22σ2ij),i=2,3,j=1,2,···,5,(9)式中:i表示输入变量;j表示每个输入变量对应的神经元;µij为第i个输入变量对应第j个神经元的隶属度;a ij,c ij和b ij分别为三角隶属度函数的两脚和峰;c ij和σij分别为高斯隶属度函数的中心和宽度.第3层为模糊推理层,该层神经元接受上一层各个输入变量以及其隶属度,匹配优化模型逻辑规则中各个规则的适用度,完成模糊推理工作.由于模糊推理层的每个神经元节点都表示一条逻辑控制规则,因此本层共有80个神经元.推理层神经元的输出为αk=3∏i=1(µij)1N c={exp[−3∑i=2(x i−c ij)22σ2ij]x1−a jb j−a j}1N c,a j x1b j,{exp[−3∑i=2(x i−c ij)22σ2ij]c j−x1c j−b j}1N c,b j x1c j,j=1,2,···,5,k=1,2,···,80,(10)式中:αk表示模糊推理层每个神经元的输出;N c为推理层的补偿因子.第4层为归一化层,该层与上一层通过模糊推理规则连接,集成逻辑规则中拥有同样后置结论的规则,输出信号是规则的强度.βk=αk80∑k=1αk,(11)式中βk表示归一化层每个神经元的输出.第5层为输出层,用于表示模糊规则所占的权重,经过该层神经元处理后的信号即是隧道照明亮度调节的控制信号,表示为L c=f(80∑k=1ωkβk),(12)式中:L c为隧道照明亮度调节的控制信号;ωk是输出层与归一化层之间的连接权值;f为输出映射函数.在搭建隧道照明控制算法网络后,需要对网络进行学习训练,以此优化调整隶属函数的中心和宽度、神经元的权重,进而确保网络的可靠性.因此,选择一种适当的神经网络优化算法尤为重要,这决定了照明控制的精度和效率.根据公路隧道照明控制特性,选择径向基(radial basis function,RBF)神经网络算法与T-S型模糊系统相融合,形成模糊径向基(fuzzy RBF, FRBF)神经网络[29].4.3照明智能控制模型与控制流程为了提高公路隧道照明智能控制算法的泛化能力,增加数据样本的多样性,在长冲隧道数据的基础上加入不同地区公路隧道的的测量数据,形成了包含124组实测数据的照明控制数据库.将照明控制数据库中的实测数据通过前文的照明动态优化方法,计算得到每组数据对应的隧道内照明亮度优化值.从124组样本数据中随机挑选80%(99组数据)作为智能控制算法的训练样本,剩余的20%(25组数据)作为测试样本.为确保样本数据训练和测试的有效性,在样本数据训练阶段均设置目标误差为0.01,最大训练步数为1000.将照明智能控制模型计算得到的测试样本控制值与其优化值对比,得出的控制精度评价结果见图5.由图5可知,FRBF神经网络的平均相对误差为2.8%,且相对误差波动范围在10%以内.为了更全面的评价FRBF神经网络模型的控制性能,采用决定系数R2与均方根误差RMSE共同来反映控制精度. R2越接近1且RMSE越小,表明控制值与优化值之间的相关程度越高,模型拟合度越好[30].R2和RMSE的计算公式分别为R2=(2525∑k=1M k Z k−25∑k=1M k25∑k=1Z k)2[2525∑k=1(M k)2−(25∑k=1M k)2][2525∑k=1(Z k)2−(25∑k=1Z k)2],(13)。
基于模型预测控制的飞翼无人机抗侧风着陆规划技术
62电子技术Electronic Technology电子技术与软件工程Electronic Technology & Software Engineering飞机着陆阶段是最容易出现飞行事故的阶段之一,而恶劣天气是导致着陆时发生飞行事故的最主要原因[1],其中侧风是对飞机着陆影响最大的因素。
在侧风作用下,飞机会产生侧向力和力矩,其中侧向力会使飞机运动轨迹偏离预订航迹,侧向力矩会使飞机带有一定的滚转角和偏航角。
同时,在侧风作用下,飞机会产生较大侧滑角,侧滑角过大会严重影响飞机的内环控制性能和稳定性。
特别是对于飞翼无人机来说,侧向只能使用阻力方向舵进行控制,控制能力较差[2],所以在着陆阶段侧风对其内环控制影响更大。
目前,在侧风中着陆的横侧向控制策略主要有侧航法和侧滑法两种[3]。
侧航法通过将机头方向朝向侧风方向,而消除侧滑角,但是由于机头方向和跑道方向不一致,所以在接地后飞机滑跑方向与跑道中心线方向也不一致,在侧偏角过大时有冲出跑道的危险;侧滑法机头方向与跑道及地速方向一致,由于有侧风存在,会存在一定侧滑角,并且为了平衡侧滑角造成的侧力,需要飞机带一定的滚转角,而对于展弦比较大的飞翼无人机,在大滚转角下有翼尖触地的风险,也会影响飞行安全。
关于侧航法和侧滑法着陆的原理和存在问题的详细分析,见本文第1小节。
综上所述,飞翼无人机单纯用侧航法和侧滑法着陆都存在一定问题,本文结合侧航法和侧滑法的优点,提出一种基于模型预测控制(ModelPredictiveControl, MPC )[4]方法进行运动规划的抗侧风控制策略。
该策略从着陆拉平段开始,在侧向通过MPC 规划,规划出一条可行的动作轨迹,使得着陆瞬间飞机的状态满足指定值或者指定范围约束。
使用该策略可以提高飞机在复杂天气情况下的着陆安全性。
1 着陆规划策略1.1 横侧向运动模型为了便于横侧向运动进行分析与设计,先给出飞翼无人机的横侧向运动模型。
Optimization and Control of Dynamic Systems
Optimization and Control of DynamicSystemsOptimization and control of dynamic systems play a crucial role in various fields such as engineering, economics, and biology. These systems involve processes that change over time, making it essential to develop strategies to optimize their performance and ensure stability. By understanding the dynamics of these systems and implementing control mechanisms, we can improve efficiency, reduce costs, and enhance overall performance. One of the key challenges in optimizing dynamic systems is dealing with uncertainty and variability. Real-world systems are often subject to external disturbances, parameter variations, and unpredictable events, which can affect their behavior. To address this challenge, engineers and researchers develop robust control strategies that can adapt to changing conditions and maintain stability. By incorporating uncertainty into mathematical models and using techniques such as robust control and adaptive control, we can improve the performance of dynamic systems in the presence of disturbances. Another important aspect of optimizing dynamic systems is considering multiple objectives and constraints. In many cases, we need to balance competing goals such as maximizing performance, minimizing costs, and meeting safety requirements. This requires the use of optimization techniques such asmulti-objective optimization and constrained optimization, which allow us to find the best compromise solution that satisfies all requirements. By considering the trade-offs between different objectives and constraints, we can design control strategies that achieve the desired performance while ensuring system stability and reliability. In addition to addressing uncertainty and multiple objectives, optimizing dynamic systems also involves modeling complex dynamics and nonlinear behavior. Many real-world systems exhibit nonlinearities, time delays, and interactions between different components, making them challenging to control. To tackle this complexity, engineers use advanced control techniques such as model predictive control, adaptive control, and nonlinear control. These methods allow us to capture the nonlinear dynamics of the system and design control strategies that can effectively regulate its behavior. Furthermore, optimization and controlof dynamic systems require a deep understanding of system dynamics and feedback mechanisms. By analyzing the interactions between different components and feedback loops within the system, we can identify key variables that influence its behavior and design control strategies to regulate them. This involves developing mathematical models of the system dynamics, simulating its behavior, and tuning control parameters to achieve the desired performance. Through iterative design and testing, engineers can optimize the control system and improve its effectiveness in regulating the dynamic system. Overall, optimization and control of dynamic systems are essential for improving performance, efficiency, and reliability in various applications. By addressing uncertainty, considering multiple objectives, modeling complex dynamics, and understanding feedback mechanisms, we can design control strategies that ensure stability and optimal performance. Through the use of advanced control techniques and optimization methods, engineers can tackle the challenges posed by dynamic systems and achieve superior results. By continuously refining and optimizing control strategies, we can adapt to changing conditions and improve the overall performance of dynamic systems.。
Robotics and Control
Robotics and Control## Robotics and Control: A Balancing Act of Precision and Intuition Theintricate dance of robotics and control lies at the heart of technological progress, shaping the future of industries and human interaction. As robots become increasingly autonomous, the responsibility to guide their actions falls on the meticulous art of control system design. This intricate balance between precision and adaptability requires a nuanced understanding of the robot's physical capabilities, the environment it operates in, and the desired task it must accomplish. From the perspective of the robot, control systems are the nervous system that translates human commands into precise movement. Sensors gather data about the environment, feeding it into the control algorithms. These algorithmsthen calculate the necessary joint velocities and forces to achieve the desired trajectory. Sophisticated control techniques, such as impedance control andadaptive control, further enhance the robot's ability to handle diverse situations. However, the robot's control system is only one half of the equation. The otherhalf lies in the meticulous engineering of the robot's physical design. Factorssuch as joint kinematics, payload capacity, and sensor accuracy all play a crucial role in determining the robot's controllability. Designers must carefully consider these factors during the robot's development stage to ensure optimal performanceand adaptability. Furthermore, the environment in which the robot operates significantly impacts its control requirements. Factors such as the presence of obstacles, varying terrain, and dynamic conditions require the robot to adjust its control strategy on the fly. Robust control algorithms must be able to handle uncertainties and disturbances, ensuring seamless and reliable performance in diverse environments. Moreover, the ultimate goal of robotics is to augment human capabilities, not replace them. This necessitates the development of intuitive and user-friendly control interfaces. Natural language processing and machine learning techniques can enable users to interact with robots seamlessly, providing natural and intuitive control over their movements. This seamless integration betweenhuman and robot capabilities is crucial for the successful deployment of robots in various industries and sectors. In conclusion, the pursuit of precise andadaptable robotics hinges on the harmonious interplay between control systems andphysical design. By leveraging advanced technologies and prioritizing human-robot collaboration, engineers can unlock the potential of robotics to revolutionize industries and empower human capabilities across diverse fields.。
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Optimal Control and Dynamic Games: Applications in Finance, Management Science,and EconomicsIn honor of Suresh SethiAix en Provence, France, 2-6 Juin 2005PROGRAMThursday June 02From 20:00 Registration and buffet at AquabellaFriday June 03From 8:00 on Registration and welcome coffee at the conference room08:50 Christophe Deissenberg and Richard Hartl: Opening09:00-09:30 Alain Bensoussan: Suresh Sethi - Works and personality9:30-10:30 Session 1: Production, Maintenance, and Transportation I. Chair: Janice E. Carillo Eugene Khmelnitsky and Gonen Singer: A Stochastic Optimal Control Policy for aManufacturing System on a Finite Time HorizonHelmut Maurer, Jang-Ho Robert Kim, and Georg Vossen : On a State-Constrained ControlProblem in Optimal Production and Maintenance10:30-11:00 Coffee break11:00-12:30 Session 2: Marketing. Chair: Ngo Van LongRichard Hartl and Peter Kort: Advertising Directed Towards Existing and New CustomersKonstantin Kogan and Avi Herbon: A dynamic game between a wholesaler and a retailer undera limited-time promotionCharles Tapiero: Advertising and Advertising Claims Over Time12:30-14:30 Lunch14:30-16:00 Session 3: Economics and Finance I. Chair: Charles TapieroGila E. Fruchter: Dynamic Brand-Image-Based Production Location DecisionsJacek B. Krawczyk: Numerical Solutions to Lump-Sum Pension Fund Problems That CanYield Left-Skewed Fund Return DistributionsDifferentiatedCapital and the Distribution of WealthSorger:Gerhard16:00-16:30 Coffee break16:30-18:00 Session 4: Economics and Finance II. Chair: Peter KortMikulas Luptacik: Data Envelopment Analysis in a dynamic frameworkAndreas Novak: Finding optimal tax rates with conflicting social and financial goalsEllina Grigorieva and Eugenie Khailov: Chattering Optimal Control Arising in aProblem of Profit MaximizationMicroeconomicFREE EVENINGSaturday June 04From 8:30 on Welcome coffee at the conference room09:30-10:30 Section 5: Production, Maintenance, and Transportation II. Chair: Ali Dogramaci Janice E. Carrillo: The Impact of Dynamic Demand and Dynamic Net Revenues on FirmClockspeedDirk Helbing and Stefan Lämmer: Self-Organized Control of Irregular or PerturbedTrafficNetwork10:30-11:00 Coffee break11:00-12:30 Section 6: Methodological Advances. Chair: Helmut MaurerAlain Bensoussan: T.B.A.Dean Carlson and George Leitmann: The Direct Method for a Class of Infinite HorizonGamesDynamicJerzy A. Filar and Boda Kang:Time Consistent Dynamic Risk Measures12:30-14:30 Lunch14:30-16:30 Session 7: Environment. Chair: Gerard SorgerHassan Benchekroun, Ngo Van Long, and Seiichi Katayama: Capital Resource Substitution, Overshooting,SustainableDevelopmentandMasatoshi Fujisaki, Seiichi Katayama, and Hiroshi Ohta: Accumulation with Random JumpUri Shani, Yacov Tsur, and Amos Zemel: Characterizing Dynamic Irrigation Policies viaGreen's TheoremNgo Van Long: Transboundary Pollution Game with Asymmetric Payoff and Preferences 16:30-17:00 Coffee break17:00-18:00 Session 8: Economics and Finance III. Chair: George LeitmannFlorian Wagener: Bifurcations in economic dynamic optimisationHerbert Dawid and Christophe Deissenberg: Should we trust governmental announcements? A analysisdynamic19:00 sharp Departure for the banquet at Chateau de Meyrargues. A bus will be waiting at the parking of Aquabella. Those who miss the bus will have to take a taxi (about 50 Euros).Any taxi driverwill know the address. The phone number of Chateau de Meyragues is 04 42 63 49 90.Abstracts, in order of presentation++++++++++++++++++++++++++++++++Alain BensoussanUniversity of Texas at DallasSuresh Sethi: Works and personalityAbstract not available++++++++++++++++++++++++++++++++Eugene Khmelnitsky and Gonen Singer, Tel-Aviv University, IsraelA stochastic optimal control policy for a manufacturing system on a finite time horizonWe consider a problem of optimal production control of a single reliable machine. Demand is described as a discrete-time stochastic process. The objective is to minimize linear inventory/backlog costs over a finite time horizon. Using the necessary conditions of optimality, which are expressed in terms of co-state dynamics, we develop an optimal control policy. The policy is parameterized and its parameters are calculated from a computational procedure. Numerical examples show the convergence or divergence of the policy when the expected demand is greater or smaller than the production capacity. A non-stationary case is also presented++++++++++++++++++++++++++++++++Helmut Maurer, Jang-Ho Robert Kim, Georg Vossen, University of Muenster, GermanyOn a State-Constrained Control Problem in Optimal Production and MaintenanceWe consider a control problem introduced by Cho which "incorporates a dynamic maintenance problem into a production control model". For a quadratic production cost function we present a detailed numerical study of optimal control policies for different final times. The maintenance control is either composed by bang-bang and singular arcs or is purely bang-bang. In the case of a linear production cost, we show that both production and maintenance control are purely bang-bang. A recently developed second order sufficiency test is applied to prove optimality of the computed controls. This test enables us to calculate sensitivity derivatives of switching times with respect to perturbation parameters in the system. Furthermore, numerical results are presented in the case where a state constraint on the number of good items is added to the control problem.++++++++++++++++++++++++++++++++Richard Hartl, University of Vienna, Austria and Peter Kort, University of Tilburg, The Netherlands Advertising Directed Towards Existing and New CustomersThis paper considers a specific marketing problem based on a model by Gould (1970). The extension is that we have two kinds of advertising directed towards new customers and existing customers, respectively We found that history dependent behavior occurs: if initial goodwill is small then it does not pay to spend a lot of money on advertising towards existing customers. Consequently convergence to a saddle point with low goodwill prevails where there is only advertising with the aim to attract new customers. On the other hand, for larger initial goodwill, eventually a steady state with a high goodwill level is reached where both types of advertising are used.++++++++++++++++++++++++++++++++Konstantin Kogan and Avi Herbon, Department of Interdisciplinary studies, Bar-Ilan University, IsraelA dynamic game between a wholesaler and a retailer under a limited-time promotionWe consider a two-echelon supply chain with a supplier and a retailer which face stochastic customer demands. The supplier is a leader who chooses its wholesale price. In response, the retailer orders products and sets up its price which affects customer demands. The goal of both players is to maximize their profit. We find the Stackelberg equilibrium and show that it is unique not only when the chain is in a steady state but also when it is in a transient state induced by a promotion. There is a maximum length to the promotion, however, so that an equilibrium still exists. Moreover, if the customer sensitivity increases during a promotion, then the wholesale equilibrium price decreases, product orders increase and product prices drop. This effect, well observed in real life, does not, however, necessarily imply that the promotion is always beneficial.++++++++++++++++++++++++++++++++Charles Tapiero, ESSEC, France, and Polytechnic University of New YorkAdvertising and Advertising Claims over TimeAdvertising budget allocation with a carryover effects over time is a problem that was treated extensively by economists. Additional developments were carried out by both Sethi who has also provided some outstanding review papers and my own. The model treated by Sethi were essentially defined in terms of optimal control problems using deterministic advertising models while my own were essentially sales response stochastic models with advertising budget determined by stochastic control problems. These problems continue to be of academic and practical interest. Issues relating to the "advertising message" such as truthful claims advertising directed to first time buyers has not attracted much attention however.The purpose of this paper is to address issues relating to advertising and their messages by suggesting a stochastic advertising-repeat purchase model. In this model, advertising directed to first time buyers is essentially defined by two factors: the advertising budget and the advertising message (such as statement regarding the characteristics of a product, its lifetime etc.). Consumers experience in case they buy the product will define the advertising message "reliability", namely that the probability that advertised message are confirmed or not. Repeat purchasers, however, are influenced by two factors, on the one hand the advertising messages that are directed to experienced consumers and of course the effects of their own experience (where past advertising claims whether truthful, or not, interact with customers' personal experience). Advertising claims that underestimate products characteristics might be "reliable" but then they might not entice first time purchasers, while overly optimistic advertising messages might entice first time purchasers but be perceived as unreliable by repeat purchasers who might switch to other competing brands. In this sense, the decision to advertise is necessarily appended by the decision to "what to advertise", which may turn out to be far more important for a firm. This paper provides a theoretical approach to deal with this issue.++++++++++++++++++++++++++++++++Gila E. Fruchter, Graduate School of Business Administration,Bar-Ilan University, Ramat-Gan 52900, Israel Dynamic Brand-Image-Based Production Location DecisionsIn this paper, we study the dynamic production location decisions of a manufacturer of a certain branded product. Considering brand-image as a form of goodwill, we extend the well-known Nerlove-Arrow dynamic model by adding both country-image and price. Formulating an optimal control problem for a group of countries in which the cost of production is convexly increasing with country-image, we are able to develop optimal decision rules for a manufacturer regarding the location of production and pricing over time. The resulted optimal policy has a very interesting pattern. Assuming that the demand rises by more than the corresponding change in brand-image, then, if brand image is increasing toward a stationary value level, the optimal policy should be to initially locate production in countries with high image and set a high price that signals high quality. Later, the production should gradually shift to countries with lower production costs and lower image and the price lowered until the stationary value level is reached. For brand-images beyond the stationary value level, the location of production should start in a country with low costs and country image while setting prices that signalrelatively low quality. Over time, production should be shifted to countries with gradually higher costs and images while setting higher prices until the brand-image approaches the level of stationary value.++++++++++++++++++++++++++++++++Jacek B. Krawczyk, KIER, Kyoto University; on leave from: Victoria University of Wellington, New Zealand Numerical Solutions to Lump-Sum Pension Fund Problems That Can Yield Left-Skewed Fund Return DistributionsThe paper is about pension fund problems where an agent pays an amount x_0 to the fund manager and is repaid, after time T, a lump sum x(T). Such problems admit an analytical solution for specific, rather unrealistic mathematical formulations. Several practical pension fund problems are converted in the paper into Markov decision chains solvable through approximations. In particular, a couple of problems with a non-differentiable asymmetric (with respect to risk) utility function are solved, for which left-skewed fund-return distributions are reported. Such distributions ascribe more probability to higher payoffs than the right-skewed ones that are common among analytical solutions.++++++++++++++++++++++++++++++++Gerhard Sorger, Department of Economics, University of ViennaDifferentiated Capital and the Distribution of WealthWe present a one-sector growth model with finitely many households who differ from each other with respect to their endowments, their preferences, and the type of capital supplied to firms. There is monopolistic competition on the capital market and perfect competition on all other markets. We show that there exists a unique stationary equilibrium and that all households have strictly positive wealth in this equilibrium. We study how the stationary equilibrium depends on the time-preference rates of the households and on the elasticity of substitution between different types of capital. We also analyze the stability of the stationary equilibrium.++++++++++++++++++++++++++++++++Mikuláš Luptáčik, Vienna University of Economics and Business Administration, AustriaData envelopment analysis in a dynamic frameworkData envelopment analysis (DEA) is well developed and widely used approach for measuring of efficiency. Based on the pioneering work of Farrel (1967), production efficiency has been measured as the distance between an observation and an efficiency frontier estimated in a way consistent with the underlining economic theory of optimizing behaviour. Using such an efficiency frontier as a benchmark, one can naturally define productive inefficiency. However, except for a few studies in the DEA literature, most previous work was dealing within a static framework and failed to model the intertemporal behaviour. The first steps towards the development of dynamic DEA have been taken by Sengupta (1995) and Färe-Grosskopf (1996). In the more recent papers Nemoto and Goto (1999), (2003) extended DEA to a dynamic framework by treating quasi-fixed inputs at the end of the period as if they were outputs in that period. The role of quasi-fixed inputs is 2-fold: they are put into today´s production as “inputs” but are also treated as yesterday’s “outputs”, which introduces a dynamic interdependency across periods. This implies that a firm cannot hold more quasi-fixed inputs without giving up a certain amount of products. Furthermore, it also implies that the more quasi-fixed inputs are maintained, the more goods or services will be produced in the next period. The augmented DEA model can be formulated as linear programming problem from which the optimal condition for the adjustment path of quasi-fixed inputs are explicitly derived. This optimality condition is the Hamilton-Jacobi-Bellman equation in dynamic programming problem of a firm’s optimizing behavior. Based on this equation a measure of dynamic inefficiency is obtained. An application to Japanese electric utilities over the 1981-1995 period by Nemoto-Goto (2003) delivered interesting results and proved the usefulness of the procedure.++++++++++++++++++++++++++++++++Andreas Novak, University of Vienna, AustriaFinding optimal tax rates with conflicting social and financial goalsPoliticians and pressure groups often try to attain different goals with taxes. On one hand taxes are necessary to generate funds for public projects, on the other hand some taxes are used in order to change the behavior of those who have to bear them. Examples for that are taxes on certain drugs like tobacco and alcohol.In an analytic static optimization model we determine the optimal tax rate when two conflicting goals like financial and social aims shall be attained to a certain degree. After deriving optimality conditions we proceed with a comparative static analysis.++++++++++++++++++++++++++++++++Ellina Grigorieva* (Texas Woman’s University, USA) and Eugenie Khailov (Moscow State University, Russia)Chattering Optimal Control Arising in a Microeconomic Problem of Profit MaximizationThe process of production, storage, and sales of a perishable consumer good is described by the following nonlinear system of three differential equations, and controlled by the rate of production.⎪⎪⎩⎪⎪⎨⎧>=>=>=−−−=−−=∈+−−=0)0( ,0)0( ,0)0()()()())()()()())(()(],0[ ),()())(()(0330220111212321122121x x x x x x t u t x k t x x Y pn t x t x k t x t x Y n t x T t t u t x t x Y n t x p p p &&&The objective of this work is to find such optimal production strategy that maximizes firm’s cumulative profit over certain time interval. Parameters of the model, for which singular control can be optimal, are defined. It is analytically proven that so-called “chattering control” appears as a link between optimal regular and optimal singular arcs. The time intervals on which chattering control occurs are found. Numerical results are obtained with the use of a computer program written in DELPHI. Possible economic applications are discussed. ++++++++++++++++++++++++++++++++Janice E. Carrillo, Warrington College of Business, University of FloridaThe Impact of Dynamic Demand and Net Revenues on Firm Clock speedThis paper yields analytic insights concerning the optimal pacing of new product development activities at the firm level. Using a simple analytic model, an optimal firm "clock speed" is derived. The derived clock speed is mostly dependent on marketing, technology, and operations related factors such as (i) average demand forecasts, (ii) dynamic profits earned over time, (iii) cannibalization of older products, and (iv) technology and/or production constraints limiting the pace of new product development.Two different cases exist and may be appropriate for different types of firms. In the first type, the speed of new product introduction is not dictated by the organizational capabilities. In this type of industry, the optimal clock speed which maximizes profits for the firm actually lags the maximal pace that the firm could achieve. In contrast, the second case depicts the situation where the speed of new product introduction is dictated by the firm's organizational capabilities. In this case, an incentive exists for firms to invest in enhancing its production, design, and/or supply related capabilities to increase the frequency of new product introductions.A key factor influencing firm clock speed is the anticipated shape of the demand/sales curve for each generation of a new product. Analytic results show that when demand curves are relatively flat, there is little incentive for the firm to introduce multiple generations of new products, particularly if development costs are formidable. In contrast, when demand curves are declining and development costs are low, the firm should introduce new products at the maximal pace possible with its current organizational capabilities. Finally, when the demand curves follow a traditional growth and decline pattern typically associated with the classical diffusion process, the firm optimally introduces each new generation of products after the old product has reached the declining phase of the product life cycle.++++++++++++++++++++++++++++++++Dirk Helbing and Stefan Lämmer, Dresden University of TechnologySelf-Organized Adaptive Signal Control in a Fluid-Dynamic Traffic Flow Model of Urban Queuing Networks We present a fluid-dynamic model for the simulation of urban traffic networks with street sections of different lengths and capacities. The model allows one to efficiently simulate the transitions between free and congested traffic based on an integrated Lighthill-Whitham model. On top of this, we observe non-linear dynamic patterns which are produced by the respective network topology. Synchronization is only one interesting example and implies the emergence of green waves. In this connection, we will discuss adaptive strategies of traffic light control which can considerably improve throughputs and travel times, using self-organization principles based on local interactions between vehicles and traffic lights. Similar adaptive control principles can be applied to other queuing networks such as production systems.++++++++++++++++++++++++++++++++Alain Bensoussan University of Texas at DallasT.B.A.Abstract not available++++++++++++++++++++++++++++++++Dean A. Carlson, Mathematical Reviews and George Leitmann, University of California at BerkeleyThe Direct Method for a Class of Infinite Horizon Dynamic GamesIn this paper we present an extension of a direct solution method, originally due to Leitmann for single-player games on a finite time interval, to a class of infinite horizon N-player games in which the state equation is affine in the strategies of the players. Our method, based on a coordinate transformation method, gives sufficient conditions for an open-loop Nash equilibrium. An example is presented to illustrate the utility of our results.++++++++++++++++++++++++++++++++Jerzy A. Filar and Boda Kang, University of South AustraliaTime Consistent Dynamic Risk MeasuresAbstract not available++++++++++++++++++++++++++++++++Hassan Benchekroun, McGill University, Ngo Van Long, McGill University, Seiichi Katayama, Kobe UniversityCapital Resource Substitution, Overshooting, and Sustainable DevelopmentIn this paper, we study the optimal path for an economy that produces an output using a stock of capital and a resource input extracted from a stock of renewable natural resource. We retain the Solow-Dasgupta-Heal assumption that capital and resource are substitutable inputs in the production of the final good, but our model differs from theirs because the resource stock is renewable. We wish to find the optimal growth path of the economy under the utilitarian criterion. We show that there exists a unique steady state with positive consumption. We ask the following questions: (i) Can it be optimal to get to the steady state in finite time under the assumption that the utility function is strictly concave? (ii) Can finite-time approach paths to the steady state be smooth, in the sense that there are no jumps in the control variables? (iii) Are there non-smooth paths to the steady state?We show that starting from low levels of capital stock and resource stock, the optimal policy consists of three phases. In phase I, the planner builds up the stock of man-made capital above its steady state level, while the resource stock is kept below its steady state level. In phase II, the capital stock declines steadily, while the resource stock continues to grow, until the steady state is reached. In phase III, the economy stays at the steady state. Thus, our model exhibits the "overshooting" property.++++++++++++++++++++++++++++++++Masatoshi Fujisaki, Seiichi Katayama, and Hiroshi Ohta, Kobe University, JapanCommon Property Resource and Private Capital Accumulation with Random JumpLong and Katayama (2002) presented a model of exploitation of a common property resource, when agents can also invest in private and productive capital. They considered the case where the resource extracted from a common pool is non-renewable. In this paper, we try to extend their result to the case where the common pool is under uncertainty in the sense that it could have a sudden increase or decrease in the process of extraction and moreover we shall calculate the exhaustion probability of the resource.++++++++++++++++++++++++++++++++Uri Shani, the Hebrew University of Jerusalem, Yacov Tsur, The Hebrew University of Jerusalem and Amos Zemel, Ben Gurion University of the NegevCharacterizing Dynamic Irrigation Policies via Green’s TheoremWe derive irrigation management schemes accounting for the dynamic response of biomass yield to salinity and soil moisture as well as for the cost of irrigation water. The turnpike structure of the optimal irrigation policy is characterized using Green's theorem. The analysis applies to systems of arbitrary end conditions. A numerical application of the turnpike solution to sunflower growth under arid conditions reveals that by selecting the proper mix of fresh and saline water for irrigation, significant savings on the use of freshwater can be achieved with negligible loss of income.++++++++++++++++++++++++++++++++Ngo Van Long, McGill UniversityTransboundary Pollution Game with Asymmetric Payoff and PreferencesWe study a model of transboundary pollution where countries have asymmetric payoff and preferences. Countries have different technological coefficients of emissions and abatements. A Markov perfect equilibrium is found for each set of parameter values. The rich country can induce the poor country to reduce emissions by offering an income transfer scheme. Under our assumption, the fraction of income transferred per period turns out to be a constant.++++++++++++++++++++++++++++++++Florian Wagener, University of AmsterdamBifurcations in economic dynamic optimizationAbstract not available++++++++++++++++++++++++++++++++Herbert Dawid, University of Bielefeld and Christophe Deissenberg, Université de la Méditerranée and Greqam Should we trust governmental announcements? A dynamic analysisWe consider a version of the seminal Kydland-Prescott model where, in each period, some private agents believe the policy announcements made by the government. The other agents follow a standard optimizing strategy. The fraction of agents who believe the government changes over time according to a word-of-mouth learning process. We show that the initial number of believers and the speed of learning can have drastic consequences for the policy followed and the losses experienced by the different agents. In particular, the utility of the private sector may jump upwards if the initial number of believers exceeds a given threshold.++++++++++++++++++++++++++++++++List of participantsName Email Affiliation Bensoussan Alain alain.bensoussan@ University of Texas at Dallas Carlson Dean. A. dac@ MathematicalReviews Carrillo Janice carrilje@ UniversityofFlorida Deissenberg Christophe deissenb@univ-aix.fr Université de la MéditerranéeDogramaci Ali rector@.tr Bilkent UniversityFeinberg Fred feinf@ University of MichiganFruchter Gila E. fruchtg@mail.biu.ac.il Bar-Itar UniversityGrigorieva Ellina egrigorieva@ Texas Woman's UniversityMartin-Herran Guiomar guiomar@eco.uva.es Universidad de ValladolidHartl Richard Richard.Hartl@UniVie.ac.at UniversityofViennaJi Yonghua yji@ualberta.ca UniversityofAlbertaKang Boda Katayama Seiichi Khailov E. Nikolaevich boda.kang@.aukatayama@rieb.kobe-u.ac.jpKhailov@cs.msu.suUniversity of South AustraliaKobe UniversityUniversity of MoscowKhmelnitsky Eugene xmel@eng.tau.ac.il Tel-Aviv UniversityKogan Konstantin kogank@mail.biu.ac.il Bar-Ilan UniversityKort Peter Kort@uvt.nl University of TilburgKrawczyk Jacek Jacek.Krawczyk@ Victoria University of WellingtonLämmer Stefan traffic@stefanlaemmer.de Dresden University of TechnologoyLeitmann George gleit@ University of California at BerkeleyLuptáčik Mikuláš mikulas.luptacik@wu-wien.ac.at WU WienManolova Petia petia@univ-aix.fr Université de la MéditerranéeMaurer Helmut maurer@math.uni-muenster.de University of MünsterNovak Andreas andreas.novak@univie.ac.at UniversityofViennaOhta Hiroshi ohta@kobe-u.ac.jp Kobe UniversitySethi Suresh sethi@ University of Texas at DallasSorger Gerhard gerhard.sorger@univie.ac.at UniversityofViennaStecke Kathryn E. kstecke@ University of Texas at DallasTapiero Charles S. tapiero@essec.fr Polytechnic University of New York and ESSEC Van Long Ngo ngo.long@mcgill.ca Mc Gill UniversityWagener Florian wagener@uva.nl University of AmsterdamZemel Amos amos@bgu.ac.il Ben Gurion University of the Negev。