基于模糊滑模观测器的永磁同步电机进给系统速度估计

Speed Sensorless Control of Permanent Magnet Synchronous Motor Based on Fuzzy Sliding Mode Observer

为解决目前伺服系统中采用机械位置传感器所存在的诸多缺点,提出一种用于永磁同步电机(PMSM)进给系统的模糊滑模速度观测器,实现无速度传感器控制。针对传统滑模观测器的抖振问题,采用Sigmoid函数代替传统理想开关函数,并引用模糊控制器自适应调整滑模增益以减小抖振,实现软切换连续控制。估计反电动势可以直接由控制函数的输出获得,省略了传统观测器中的低通滤波器和相角补偿。利用李亚普诺夫函数证明了设计的滑模观测器的渐进稳定性。仿真结果表明:设计的模糊滑模观测器能够对PMSM转子速度进行精确辨识,并有良好的动、稳态性能。

To solve many defects existing in the mechanical speed sensor of servo system, a fuzzy sliding mode speed observer was proposed for the feed system of the permanent magnet synchronous motor. Focused on the chattering problem of conventional sliding mode observer （SMO）, sigmoid function was used instead of the traditional ideal switch function and fuzzy control system was used to adjust the gain of the SMO. This method could decrease undesirable chattering phenomenon and realized the soft control. Detecting back EMF could be done directly from switching signal without any low pass filter. So the delay time because of low-pass filter, in the proposed observer was eliminated and there was no need to compensate phase fault in position estimating. The asymptotic stability of the designed sliding mode observer was proved by Lyapunov function. The simulation results showed that the designed fuzzy sliding mode observer could accurately identify the rotor speed of PMSM, and had good dynamic and static performance.