High-order terminal sliding mode based mechanical resonance suppressing method in servo system

This paper proposes a mechanical resonance suppressing method based on high-order sliding mode and non-singular terminal sliding mode for servo system. Non-singular terminal sliding mode manifolds are designed for load speed and stator currents of the permanent magnet synchronous motor to realize both fast convergence and better tracking precision. A state observer is utilized to estimate the shaft torsion angle and the load speed. And a high-order sliding mode control law is designed to eliminate the chattering and guarantee the stability of the system. Simulation results show that, compared with the acceleration feedback and the notch filter method, the proposed method in this paper can suppress mechanical resonance more effectively, and the motor speed converges fast without overshoot.