基于七阶EKF的永磁直线伺服系统变质量估计和扰动补偿

永磁直线同步电动机(PMLSM)伺服系统易受摩擦力和推力波动等外部扰动的影响,为保证系统按照期望轨迹运动,需要对这些扰动进行补偿,而且系统质量信息的准确性对扰动补偿能力有很大影响。针对这一问题,提出一种基于扩展卡尔曼滤波器(EKF)的变质量估计和扰动补偿方法。首先,建立与电机位置有关的扰动模型,作为扰动补偿器。然后,采用七阶EKF计算电机初始位置、估计质量的变化并反映到扰动补偿器中,同时通过自适应律整定扰动模型系数确保扰动模型与实际扰动保持同步,实现对系统的变质量估计和扰动补偿。实验结果证明了所提控制方案的有效性与可行性,明显提高了系统的位置跟踪性能和抗扰性能。

Varying mass estimation and disturbance compensation for permanent magnet linear servo system based on 7th-order EKF

The permanent magnet linear synchronous motor(PMLSM)servo system is vulnerable to influence of external disturbances such as friction force,force ripple and so on.It is necessary to compensate for these disturbances to ensure that the system moves in accordance with desired trajectory.Moreover,the accuracy of the system mass information has a great influence on the disturbance compensation capability.For this problem,a varying mass estimation and disturbance compensation method based on extended Kalman filter(EKF)was proposed.Firstly,the disturbance model related to the motor position was established as the disturbance compensator.Then,the 7th-EKF was used to calculate the initial position of the motor and the change of the estimated mass,which is reflected in the disturbance compensator.At the same time,the coefficient of the disturbance model was adjusted by the adaptive law to ensure that the disturbance model and the actual disturbance remain synchronous to realize the variable mass estimation and disturbance compensation of the system.The experiment results demonstrate effectiveness and feasibility of the proposed control scheme.The position tracking and disturbance rejection performance of system are improved greatly.