Mechanical Resonance Suppression Research Based On Sliding Mode Control

When driving loads, motors and loads constitute dual inertia system. The system will inevitably produce mechanical resonance due to the nature of the model itself. Which intuitive performance in angular difference between motor and load. Meanwhile, the bode diagram appears peak value. The mainly harm manifested in mechanical parts of equipment damage, making the equipment can’t meet the design requirements, reducing its service life. The problem of inhibition of mechanical resonance has become an important reference index in judge a high performance servo system.This paper analyzed resonance suppression with traditional method, which using equal effective in motor end and load end inertia, and the control strategy is mainly aimed at motor side. Based on PI control methods aims to increase the system damping while based on notch filter needs detect or estimate the resonance frequency of the system. And only by then can we design the digital filter. Those methods have the problem of robustness, which restricted the engineering applications in practical.In this paper, the research object is dual closed loop speed system. Using high order(three order) sliding model in speed controller while using second order sliding model in current controller. The controlled object is dual inertia system using PMSM as driving motor. Analyzed the design principle and process of sliding mode controller, put forward a new reaching law, and verified the reaching rapidity in the process. Design a sliding mode observer used in the system, analysis the presence with disturbance observation and accuracy, and then verified by Simulink. Through compare with motor speed feedback and load speed feedback in speed control system, verified the effectiveness of inhibition resonance by using load speed feedback. And enhance the robustness of the system at the same time.