Speed tracking control for permanent magnet linear synchronous motor with sliding mode and back-stepping

Both load disturbance and variation of motor parameter can reduce the servo performances of the system. To eliminate the influences of the above-mentioned uncertainties and ensure the tracking capability of the system, a speed tracking control strategy combined back-stepping control with variable structure control (VSC) was proposed. The back-stepping method can ensure the global ultimate asymptotical stability. However, the disturbance of changing faster and larger can't be ideally eliminated with this method. The VSC has such advantages as high response and invariability to uncertainties. Combining variable structure control with back-stepping control can not only provide the better speed tracking performance, but also assure the robust performance of the system when the motor parameters and external load change. In addition, the simulation using Matlab proves the effectivity and feasibility of the proposed method.