基于力/位混合控制的工业机器人精密轴孔装配

Industrial robot high precision peg-in-hole assembly based on hybrid force/position control

为了研究工业机器人在高精密装配领域的应用,针对高精密装配中典型的轴孔装配问题,提出精密轴孔装配流程以及新的力/位混合控制策略实现方式:装配流程包括搜孔、插入、完成3个阶段;新的力/位混合控制策略是基于伺服速度环实现,与传统基于伺服位置环实现的力控制系统相比较具有更大的系统带宽,控制系统结构简单,方便实现,也可以把速度信号进行积分,转化为伺服位置环控制的实现方式,开展仿真和实验以验证方法的有效性,仿真结果表明,基于速度环实现的力控制能够更好地跟踪更高频率的正弦给定信号,具有较好的力跟踪性能.实验采用工业机器人大臂减速机的装配,实验结果表明,采用力/位混合控制方法和螺旋搜孔的方式能够顺利地找到装配孔,很好地完成轴孔装配作业.

A peg-in-hole assembly strategy and a new implementation of hybrid force/position control strategy were proposed,in order to analyze the application of industrial robot in high precision assembly field and solve the typical peg-in-hole problem in high precision assembly.The assembly process included three stages：search,insert and complete.The proposed hybrid force/position control system was based on the motors velocity control loop,and had a larger system bandwidth compared to the traditional force control system based on position control loop.The control structure was simple and easy to implement,and could integrate the velocity signal,and transform into implementation based on the motors position control loop.The simulation and experiment were conducted to verify the effectiveness of the method.The simulation results show that the force/position hybrid control method based on the velocity control loop has better performance to track higher frequency sinusoidal signal than traditional method which is based on the position control loop.The industrial robot was used to assembly the reducer of robot arm.Experimental results show that the force/position hybrid control method with spiral search hole strategy can find the assembly hole and finish the peg-in-hole assembly task well.