基于状态观测器增益自调整的交流伺服系统

针对永磁同步交流伺服系统易受机械参数的变化和负载扰动的影响,论文设计了一个负载观测器,并采用递推最小二乘法对系统的转动惯量和粘滞摩擦系数进行了在线辨识,然后用辨识得到的转动惯量和粘滞摩擦系数对系统参数进行更新,保证了观测器的精度。采用极点配置法设计的观测器增益可以根据前面估计得到的转动惯量和粘滞摩擦系数在线调整,使该观测器在自身的机械参数发生剧烈变化时,仍能准确地观测突加的外部负载扰动进行补偿,大大提高了伺服系统的精度。仿真结果表明,系统在转动惯量和粘滞摩擦系数发生变化时,基于负载观测器增益自调整的高精度永磁交流伺服系统无论是在上升时间,速度跟踪的精确性和鲁棒性方面都优于传统的负载观测器的增益固定的控制方案。

AC servo system based on gain self-tuning state observer

For the characteristic of permanent magnet synchronous motor servo system is prone to suffer from the effect of load disturbances and parameters variations,this paper designs a load observation and identifies the inertia and friction coefficient of the system on-line based on RELS(recursive extended least square).In order to guarantee the precision of observer,rotational inertia and friction coefficient that have been identified are used to update the parameters of the system and the gain of observer can self-tune on-line based on the identified rotational inertia and friction coefficient by pole assignment,so the observer can observe the sudden external load disturbance precisely and compensate accordingly when the parameters of the system varied severely.By doing so,the precision of the servo system can be improved greatly.The simulation results show that the high precision permanent magnet synchronous motor servo system based gain self-tuning load observer outperforms the traditional one based on fixed gain load observer in rise time,precise track of velocity,and robustness when the inertia and friction coefficient varied.