高速高精运动控制补偿及参数校准技术

华中科技大学

硕士学位论文

高速高精运动控制补偿及参数校准技术

姓名：朱凯

申请学位级别：硕士

专业：机械电子工程

指导教师：李小清

2011-01-14

摘要

随着现代制造业的迅速发展，高速度、高精度已成为现代运动控制追求的主要目标，开展高速高精运动控制的研究，对我国数字化装备制造业水平和竞争力的提升有着重大的意义。本文将着重对高速高精运动控制补偿及参数校准技术展开深入研究与实践。

数控机床工作台采用直线电机和主轴旋转电机的复合运动，实现高速、高精、多自由度的运动性能，其控制为多刚体、多变量、强耦合的非线性系统控制。对此，本文根据高速高精运动控制系统的性能要求，设计了系统硬件体系和软件构架。其中，系统硬件采用基于PCI总线的IPC+8136卡结构，软件包括人机界面、任务调度、信息交换缓冲、插补处理及位置控制等；针对复杂的曲线曲面加工中存在的小线段“拐点”问题，采用柔性度较好的S型曲线加减速控制来避免运动过程中产生的冲击，建立小线段高速加工速度、加速度衔接模型，对连续小线段衔接处的拐点速度及加速度约束条件进行讨论，同时对小线段速度进行插补预处理，以满足高速高精运动控制的要求；结合机床工作台通用的运动控制结构，研究了对控制精度具有较大影响的外部扰动因素，并设计了适用于高速高精的伺服运动控制结构，对其中的参数校准技术进行深入研究。

针对驱动系统的非理想因素，提出轨迹点前馈补偿校准技术，详细阐述前馈质量和前馈延时系数校准算法，推导出加速度前馈校准流程，极大的提高控制系统的高速响应特性；机床在运动过程中不可避免的存在谐振，通过计算系统传递函数，分析系统性能评价指标，设计Notch陷波滤波器参数，抑制机械谐振，提高加工精度；采用带二阶低通滤波的PID反馈控制器，基于积分误差最小的灵敏度约束方法对控制参数进行整定，抑制高频噪声，提高系统稳定性；研究伺服电机Cogging力/力矩产生机理，提出伺服电机齿槽推力波动的校准补偿，降低Cogging力/力矩对运动精度的影响。

最后，搭建高速高精运动控制补偿及参数校准技术试验平台，进行了PID调节、Notch滤波和小线段S型曲线加减速插补算法验证试验。试验表明本文方法可行有效。

关键词：高速高精小线段前馈补偿陷波滤波PID反馈

Abstract

With the rapid development of modern manufacturing, high-speed、high-precision become the main objectives which are pursued by the modern motion control. Carrying out high speed and high precision motion control research enhances the level and competitiveness of the manufacturing of digital equipment, and has great significance. This paper will focus the in-depth study on technique of compensation and parameter calibration for high-speed and high-precision motion control.

The combined movement is generated by the linear motor and the spindle motor of the table of CNC. In order to meet high speed、high precision and multi-degree motion performance, the control is more rigid、multivariable、strong coupling of the nonlinear system control. In this regard, to meet high-speed and high-precision motion control based on system performance requirements, the hardware system and software architecture have been designed. Among them, the system hardware adopts IPC+8136 card structure based on PCI bus.The main software includes human-machine interface, task scheduling, buffer exchange of information, interpolation processing, and position control. For "turning point" problems of a small segment in the processing of complex curves and surfaces, better use of flexible S-curve acceleration and deceleration control to prevent the impact during movement. The establishment of link-up model in small line speed and acceleration during high-speed machining, and velocity and acceleration constraints of continuous small line at the inflection point was analysed. Meanwhile, speed interpolation pretreatment of small line was used to meet the high-speed and high-precision motion control requirements.With the study of common motion control structure, and the external disturbance factors of accuracy, servo motion control structure has been designed for meeting high-speed and high-precision, also the key technologies have been studyed in depth.

For the non-ideal factors of the drive system, feedforward compensation and calibration technique of trajectory point were proposed, including the calibration algorithm of the quality feedforward and delay factor feedforward, and get acceleration feedforward calibration process, greatly improving speed response characteristics of control systems. The inevitable existence of mechanical resonance during the motion of machine, was inhibited by the calculating of the system transfer function、the analysis of system performance evaluation and the design of NOTCH filter parameters, which improve the processing accuracy. Inhibition of high-frequency noise and improvement of system stability are fulfilled by adopting PID feedback controller with low-pass filter of second-order, and modification of the PID control