一种并联机器人误差综合补偿方法

针对并联机器人轨迹规划和轨迹跟踪过程中,同时存在机构误差引起的期望轨迹与理想轨迹之间的偏差和非线性摩擦、负载变化等扰动因素引起的动态误差,提出一种并联机器人误差综合补偿方法:在轨迹规划过程中,基于并联机器人位姿误差模型将位姿误差补偿转化为驱动杆参数组合优化问题,进而利用粒子群算法寻优驱动杆参数,修正并联机器人期望轨迹;在轨迹跟踪过程中,设计基于自适应迭代学习控制算法的动态误差补偿策略,实现对期望轨迹的有效跟踪。在Stewart平台下基于ADAMS和Matlab进行仿真试验,在轨迹规划和轨迹跟踪过程中,分别修正期望轨迹偏差并补偿轨迹跟踪动态误差,实现并联机器人误差综合补偿。进一步,基于混联机床进行工件加工试验,验证方法对于提高并联机器人工作精度的有效性。

A Parallel Robot Error Comprehensive Compensation Method

Aiming at the deviation between desired trajectory and ideal trajectory caused by the mechanism errors,and the dynamic error caused by the disturbance factors such as nonlinear friction and load change,which exist simultaneously in trajectory planning and trajectory tracking process of parallel robot,an error comprehensive compensation method for parallel robot is proposed.In the trajectory planning process,the pose error compensation is transformed to the driven rod parameters optimization problems based on the pose error model of parallel robot,then the particle swarm optimization algorithm is used to optimize driven rod parameters to correct the desired trajectory of parallel robot;In the trajectory tracking process,the dynamic error compensation strategy based on the adaptive iterative learning control algorithm is designed which can effectively track the desired trajectory.Simulation experiment on the Stewart platform is realized based on ADAMS and Matlab,which shows that the deviation of desired trajectory is corrected and the dynamic error of trajectory tracking can be compensated to realize the error comprehensive compensation of parallel robot.Furthermore,the workpiece machining experiment on the hybrid kinematics machine tools is done to test the validity of the method for improving the work accuracy of parallel robot.