谐波驱动伺服系统的改进自适应鲁棒控制

针对谐波驱动伺服系统存在参数不确定性、干扰及非线性摩擦的问题,考虑位置相关摩擦的特性,提出改进自适应鲁棒控制算法.采用未知参数的正余弦函数组合的形式表征位置相关摩擦的特性,采用库仑-黏性摩擦表征速度相关摩擦力的特性.在期望补偿自适应鲁棒控制算法的基础上,增加自适应律的比例项,提高参数辨识的性能,有效抑制系统高频干扰.理论证明了控制系统的全局稳定性.分别在考虑位置摩擦和未考虑位置摩擦的情况下,采用自适应鲁棒控制、期望补偿自适应鲁棒控制及改进自适应鲁棒控制算法对单自由度机械臂的谐波驱动伺服系统进行实验研究.结果表明,该方法具有良好的控制性能.

Improved adaptive robust control of servo system with harmonic drive

Considering the nature of position-dependent friction, an improved adaptive robust control algorithm was proposed for servo system with harmonic drive which was subject to significant nonlinear friction parameter, uncertainties and disturbance.The combination of sinusoidal and cosinoidal functions of positions with unknown weights was used to effectively capture the nature of position dependent friction, and the combination of coulomb friction and viscous friction was used to capture the nature of velocity dependent friction.A proportional part of adaptive law was applied based on the desired compensation adaptive robust controller in order to improve the performance of parameters identification and attenuate high-frequency disturbance.The global stability of the system was proved theoretically.The proposed control scheme was applied to the same single-link manipulator together with adaptive robust control and desired compensation adaptive robust control under two sets. One considered the position-dependent friction and the other did not.Experimental results confirmed the validity of the proposed control scheme by comparing it with other control strategies.