基于阻抗控制的机器人末端接触力控制系统研究

Research on the control system of robot end contact force based on impedance control

为改善机器人与环境间的末端接触力的准确性,尤其处于接触环境刚度不确定的情况。设计了弹簧作为柔性元件,采用液压系统进行驱动,采用阻抗控制对末端接触力控制系统进行建模,设计了PI控制器,分析在不同弹簧刚度以及不同环境刚度下末端接触力的控制性能。仿真结果表明,在三组不同的弹簧刚度下,系统稳态误差分别为2.85%、2.43%、2.21%,在三组不同的环境刚度下,系统稳态误差分别为1.21%、2.43%、4.87%,均符合期望接触力准确性的要求。为环境刚度不确定情况下的末端力控制提供了理论参考。

In order to improve the accuracy of the end contact force between the robot and the environment,especially when the stiffness of the contact environment is uncertain,the spring is used as a flexible component driven by hydraulic system,the impedance control is used to model the end contact force control system,the PI controller is designed,and the control performance of the end contact force under different spring/environment stiffness conditions is analyzed.The simulation results show that the steady-state error of the system is 2.85%,2.43%and 2.21%respectively under three spring stiffness conditions,and the steady-state error of the system is 1.21%,2.43%and 4.87%respectively under three environment stiffness conditions,which meet the requirements of the expected contact force accuracy.This study has provided theoretical reference for the end force control when the stiffness of the environment is uncertain.