摘要
为了解决滚珠丝杠进给系统滑模控制的抖振问题并提高系统跟踪性能,提出了一种基于变幂次趋近律的滑模控制方法.所设计的非线性干扰观测器能精确地观测出是否满足匹配条件的干扰.采用改进的变幂次趋近律提高了滑模函数的收敛速度,改善了运动品质.在控制律中设计积分补偿项消除了匀速段的稳态误差.仿真及实验结果表明:基于指数趋近律方法的最大跟踪误差仿真值与实验值分别为3.40和17.77μm,基于改进的变幂次趋近律方法的最大跟踪误差仿真值与实验值降低至2.79和11.00μm.控制电压信号中的抖振明显削弱,且增加外部干扰后仍能维持高精度.仿真及实验结果证明了基于变幂次趋近律的滚珠丝杠进给系统滑模控制方法能够有效消除抖振及匀速段的稳态误差,提高跟踪精度,且对外部干扰具有强鲁棒性.
To solve the chattering problem of sliding mode control for ball screw drives and improve the tracking performance of the system, a sliding mode control method based on variable power reaching law was proposed. The matched and mismatched disturbance could be accurately observed by the designed nonlinear disturbance observer. The improved variable power reaching law was adopted to increase the convergence speed of the sliding mode function and improve the motion quality. The integral compensation term of the control law was designed to eliminate the steady-state error at the uniform speed stage. The results show that the simulation value and experimental value of the maximum tracking error with the exponential reaching law method are 3.40 and 17.77 μm, the above values decrease to 2.79 and 11.00 μm with the improved variable power reaching law method. The chattering in the control voltage signal is obviously weakened and the tracking accuracy can still be maintained after adding external disturbance. It is proved that sliding mode control for ball screw drives based on the proposed variable power reaching law can effectively eliminate the chattering and the steady-state error at the uniform speed stage and improve the tracking accuracy meanwhile, it has strong robustness to external disturbance.
作者
韩硕
汤文成
包达飞
Han Shuo;Tang Wencheng;Bao Dafei(School of Mechanical Engineering,Southeast University,Nanjing 211189,China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第2期237-244,共8页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51675100)
国家科技重大专项资助项目(2016ZX04004008-002)
关键词
滚珠丝杠
抖振
干扰观测器
变幂次趋近律
滑模控制
ball screw
chattering
disturbance observer
variable power reaching law
sliding mode control
