机械轴承控制系统中的摩擦补偿

摘要

摩擦是机械轴承控制系统中最主要的扰动因素,也是影响系统低速跟踪性能的最主要因素.针对系统中动态摩擦力矩的影响,为了进一步提高系统的位置跟踪性能,提出一种重复自适应控制方法.该方法的控制律包含一个参数自适应律、等效PD控制律和一个重复控制律,其中,参数自适应律用来估计未知模型参数并予以补偿,而插入的重复控制器用来提高系统运行曲线的跟踪性能.系统中摩擦模型采用摩擦参数非一致性变化的LuGre动态模型.Lyapunov方法证明该补偿方法保证了闭环系统全局稳定性和对期望位置信号的渐近跟踪.最后,通过对控制系统的仿真研究验证了所提出方法的有效性.%The friction is the main disturbance factor in the mechanical bearing control system and is the main factor that influences the low velocity tracking performance of the system. In view of the influence of dynamic friction torque to the system, a repetitive adaptive control method is proposed to improve the system's position tracking performance. The compensation algorithm consists of an adaptive component, a PD component and a repetitive component. The adaptive component is used to estimate and compensate the unknown model parameters, while the repetitive controller is used to improve the tracking performance of system motion trajectory. A LuGre dynamic friction model with non-uniform variation parameters is used in the motor system, and the system stability and the uniform ultimate position tracking performance are guaranteed by the Lyapunov method. Finally, simulations for the control system testify the efficiency of the proposed method.