基于非线性扩张状态观测器的直线电机PD控制

为了解决直线电机伺服系统跟踪速度与峰化现象之间的矛盾，设计一种基于非线性扩张状态观测器的比例微分(Proportion Differentiation, PD)控制器。将直线电机伺服系统中的未建模动态和外界干扰定义为总和扰动并扩充为系统新的状态变量，利用非线性扩张状态观测器(NonLinear Extended State Observer, NLESO)估计不可测量的直线电机动子速度以及总和扰动。利用NLESO和跟踪微分器TD的输出，基于动态补偿线性化思想设计了引入补偿量的PD控制器，并给出了闭环控制系统稳定性证明。在Googol公司的实验平台上，通过与两种基于LESO的PD控制器对比，验证了所设计的基于NLESO的PD控制器的可行性。实验结果表明，基于NLESO的PD控制器可使直线电机伺服系统具有跟踪速度快、跟踪精度高、峰化现象小、鲁棒性强的优点。
In order to solve the contradiction between the tracking speed and the peaking phenomenon of the linear motor, a PD controller was proposed via nonlinear extended state observer. The unmodeled dynamics and disturbance were defined as overall disturbance and viewed as a new system state. A NLESO (nonlinear extended state observer) was designed to estimate the velocity of the mover and the overall disturbance. With the linearization via dynamic compensation, a PD controller with compensation was designed by using the outputs from the NLESO and TD, and the stability proof of closed-loop control system was given. The effectiveness of the proposed controller was verified when compared with other two PD controllers based on LESO in the experimental platform made by Googol company. Experimental results demonstrate that the linear motor servo system with the proposed PD controller via NLESO has the advantages of high tracking speed, high tracking precision, small peaking phenomenon and strong robustness.