动态环境下的机器人平滑自适应变阻抗控制

Smooth Adaptive Variable Impedance Control for Robot Force Tracking in Dynamic Environment

针对磨抛任务中的机器人柔顺恒力控制问题,提出一种动态环境下基于位置的平滑自适应阻抗控制方法。首先研究了机器人磨抛任务空间转换接触力变化过程,使用自抗扰控制中的微分跟踪器来安排过渡过程,使期望力缓慢释放,以减小接触力冲击。然后针对磨抛任务中环境位置不确定性的问题,建立自适应阻抗模型,根据接触力的变化进行自适应调整阻抗参数,实现位置的自适应补偿,并对自适应变阻抗的稳定性进行证明。最后,通过对已有的自适应变阻抗控制方法和所提出的平滑自适应变阻抗控制进行仿真实验对比,并对所提出的平滑自适应变阻抗控制进行实机验证。实验结果表明,平滑自适应阻抗控制方法能够有效地减小力超调,达到更好的力跟踪效果,提高系统的稳定性和鲁棒性。

Aiming at the compliant constant force control problem of robots in grinding and polishing tasks,a position-based smooth adaptive impedance control method in dynamic environment is proposed.Firstly,the change process of the contact force of the robot grinding and polishing task space conversion is studied,and the differential tracker in the active disturbance rejection control is used to arrange the transition process,so that the desired force is released slowly to reduce the impact of the contact force.Then,aiming at the problem of environmental position uncertainty in the grinding and polishing task,an adaptive impedance model is established,and the impedance parameters are adaptively adjusted according to the change of the contact force to realize the adaptive compensation of the position.And the stability of adaptive variable impedance is proved.By comparing the existing adaptive variable impedance control method and the proposed smooth adaptive variable impedance control by simulation experiments,the proposed smooth adaptive variable impedance control is verified in real machine.The experimental results show that the smooth adaptive impedance control method can effectively reduce the force overshoot,achieve better force tracking effect,and improve the stability and robustness of the system.