单位负反馈系统校正——自动控制原理课程设计

目录

1．设计题目...................................................................... 错误!未定义书签。

2. 摘要 (2)

3、未校正系统的分析 (3)

3.1.系统分析 (3)

3.2.单位阶跃信号下系统输出响应 (4)

4、系统校正设计 (7)

4.1.校正方法 (7)

4.2.设计总体思路 (7)

4.3.参数确定 (8)

4.4.校正装置 (9)

4.5.校正后系统 (10)

4.6.验算结果 (11)

5、结果 (13)

5.1.校正前后阶跃响应对比图 (13)

5.2.结果分析 (14)

6、总结体会 (15)

7、参考文献 (16)

1．设计题目

设单位负反馈系统的开环传递函数为：

))

1

01

.0

)(

1

(

/(

)

(+

+

=s

s

s

K

s

G

用相应的频率域校正方法对系统进行校正设计，使系统满足如下动态和静态性能：

1）相角裕度

45

≥γ；

2）在单位斜坡输入下的稳态误差为

0625

.0

≥

ss

e

；

3）系统的穿越频率大于2rad/s。

要求：

1）分析设计要求，说明校正的设计思路（超前校正，滞后校正或滞后- 超前校正）；

2）详细设计（包括的图形有：校正结构图，校正前系统的Bode图，校正装置的Bode图，校正后系统的Bode图）；

3）用Matlab编程代码及运行结果（包括图形、运算结果）；

4）校正前后系统的单位阶跃响应图。

2.摘要

用频率法对系统进行超前校正的实质是将超前网络的最大超前角补在校正后系统开环频率特

性的截止频率处，提高校正后系统的相角裕度和截止频率，从而改善系统的动态性能。为此，要求校正网络的最大相位超前角出现在系统的截止频率处。只要正确地将超前网络的交接频率1/aT和1/T设置在待校正系统截止频率Wc的两边，就可以使已校正系统的截止频率Wc和相裕量满足性能指标要求，从而改善系统的动态性能。串联超前校正主要是对未校正系统在中频段的频率特性进行校正。确保校正后系统中频段斜率等于－20dB/dec，使系统具有45°～60°的相角裕量。以加快系统的反应速度，但同时它也削弱了系统抗干扰的能力。在工程实践中一般不希望系数a值很大，当a＝20时，最大超前角为60°，如果需要60°以上的超前相角时，可以考虑采用两个或两个以上的串联超前校正网络由隔离放大器串联在一起使用。在这种情况下，串联超前校正提供的总超前相角等于各单独超前校正网络提供的超前相角之和。

2. abstract

With the frequency method of the system is the essence of advanced correction will lead the network maximum lead angle compensation at cut-off frequency after correction of opened loop frequency characteristics of the system, improve the correction system phase margin and cut-off frequency, so as to improve the dynamic performance of the system. To this end, the maximum phase lead angle of the network is required to appear at the cut-off frequency of the system. As long as the right on both sides of the advance network handover frequency 1/aT and 1/T set the cutoff frequency of the Wc in the correction system, can make the cutoff frequency Wc has correction system and phase margin meet performance requirements, so as to improve the dynamic performance of the system. Series lead correction is to correct the frequency characteristic of the system in the middle frequency band. Ensure that the corrected system of intermediate frequency is equal to the slope of 20dB/dec, the system has 45 degrees to 60 degrees of phase margin. In order to speed up the system's reaction speed, it also weakens the ability of the system to resist interference. Great general hope coefficient a value in engineering practice, when a = 20, the maximum lead angle is 60 degrees, if you need to advance angle above 60 degrees, you can consider using two or more than two series leading correction network by isolation amplifier is connected in series with the use of. In this case, series leading correction is equal to the total advance angle to provide separate lead network and provide advance angle.

关键词：串联超前校正; 动态性能; 相角裕度

Key words: Series lead correction ;Dynamic performance ;Phase margin