PID sliding mode control of floating stator permanent magnet synchronous linear motor with finite-time disturbance observer

Abstract

In the process of high-speed and high-acceleration motion, linear motors not only have inertial vibration but also have a long vibration attenuation time. Aiming at the vibration problem caused by inertia, a floating stator linear motor with a vibration reduction module is proposed to suppress inertial vibration. The vibration energy is dissipated by the stator floating structure. Taking permanent magnet synchronous linear motor (PMSLM) as the research object, the nonlinear dynamic modeling of a floating stator linear motor is established based on the compression displacement between the rubber damping module and the floating stator as the segmentation criterion. The influence of stiffness, damping, preload displacement, and mass on the vibration of the linear motor base is studied by numerical simulation. The finite element simulation of the magnetic field and flux of the fixed and floating stator states is carried out with the help of Maxwell software. The adverse effects caused by the floating stator are equivalent to bounded disturbances, and a PID sliding mode controller with a finite-time disturbance observer is proposed. The experimental results show that the floating stator can weaken the influence of inertial vibration, and the floating stator linear motor can achieve a faster and more accurate response after applying the sliding mode control based on the disturbance observer.