喷砂除锈并联机器人反步自适应滑模控制

Backstep Adaptive Sliding Mode Control of Parallel Robot for Sandblasting and Rust Removing

针对新研制的喷砂除锈并联机器人末端喷枪存在射流反作用力强烈干扰、机构建模误差及系统外部随机干扰等问题,提出一种结合射流反作用力前馈补偿的反步自适应滑模控制方法。该方法具有以下突出特点:定量分析喷砂射流反作用力并进行前馈补偿,以降低滑模控制设计负担,提高滑模控制的适应性;基于考虑了射流反作用力的并联机器人动力学模型,针对非线性系统采用反步法设计滑模控制器;根据Lyapunov方法设计自适应律,解决建模误差及系统外部的随机干扰问题,以增强系统鲁棒性,并抑制滑模控制抖振。仿真结果表明,该控制方法使喷砂除锈并联机器人在喷砂射流反作用力的强烈干扰下,仍具有良好的系统鲁棒性与轨迹跟踪效果。

In view of the problems of the newly developed sandblasting and rust removal parallel robot,the main problems are the strong interference of the jet reaction force in the end spray gun,the mechanism modeling error and the random interference outside the system,therefore a backstep adaptive sliding mode control method combined with feedforward compensation of the jet reaction force is proposed.This method has the following outstanding features:quantitatively analyze the reaction force of the sandblasting jet and per⁃form feedforward compensation to reduce the burden of sliding mode control design and improve the adaptability of sliding mode con⁃trol;based on the dynamic model of the parallel robot considering the jet reaction force,the sliding mode controller is designed by the backstepping method for the nonlinear system;design Lyapunov-type adaptive law to solve modeling errors and system external ran⁃dom interference problems to enhance system robustness and suppress sliding mode control chattering.The simulation results show that the control method proposed can make the sandblasting and rust removal parallel robot have good system robustness and trajectory tracking effect under the strong interference of the sandblasting jet reaction force.