基于零空间的冗余机器人末端执行器动态控制仿真分析

Dynamic Control Simulation Analysis of Redundant Robot End Effector Based on Zero Space

为提高冗余机器人手臂末端执行器位置追踪精度,降低控制系统的抖动幅度,文章设计了阻抗控制系统,并对控制系统输出效果进行仿真验证。创建了冗余机器人手臂位置动力学模型,推导出冗余机器人手臂在笛卡尔空间和零空间中投射的闭环动力学方程式。设计了冗余机器人手臂阻抗控制系统,消除控制系统的抖动幅度,利用李雅普诺夫函数对控制系统的稳定性进行证明。为了验证阻抗控制系统的追踪精度,利用Matlab软件在零空间中对冗余机器人末端执行器追踪精度进行仿真,并且与传统PID控制系统进行对比。结果显示:采用传统PID控制系统,冗余机器人末端执行器角位移、角速度和角加速度追踪误差较大,控制系统自适应调节时间较长;采用阻抗控制系统,冗余机器人末端执行器角位移、角速度和角加速度追踪误差较小,控制系统自适应调节时间较短。采用阻抗控制系统,冗余机器人控制系统反应迅速,执行任务追踪精度较高,运动相对平稳。

In order to improve the position tracking accuracy of the redundant robot arm end actuator and reduce the jitter amplitude of the control system,an impedance control system is designed,and the output effect of the control system is verified by simulation.The position dynamic model of redundant robot arm is established,and the closed-loop dynamic equations of redundant robot arm in Cartesian space and zero space are derived.The impedance control system of redundant robot arm is designed to eliminate the jitter amplitude of the control system.The stability of the control system is proved by Lyapunov function.In order to verify the tracking accuracy of the impedance control system,MATLAB software is used to simulate the tracking accuracy of the redundant robot terminal actuator in zero space,and compared with the traditional PID control system.The results show that the tracking errors of angular displacement,angular velocity and angular acceleration of the redundant robot end effector are large,and the adaptive adjustment time of the control system is long;the tracking errors of angular displacement,angular velocity and angular acceleration of the redundant robot end effector are small,and the adaptive adjustment time of the control system is short when the impedance control system is used.With the impedance control system,the redundant robot control system has the advantages of fast response,high accuracy of task tracking and relatively stable movement.