Friction Compensation For Permanent Magnet Synchronous Motor Based On Adaptive Backstepping Control

Permanent magnet synchronous motor(PMSM) has many advantages such assimple structure，small size，high efficiency，reliable operation and others．It playsan important role in the field of aviation and aerospace，industrial andagriculturalproduction，daily life，etc．Because of nonlinear characteristics of friction torque，wh en working in low speed range，PMSM may appear stick-slip phenomenon whichseriously affects the low-speed performance of the PMSM servo system．Based on existing achievements about friction torque，this paper studies frictiontorque models． Qualitative analysis of friction torque shows thatthere is anapproximate linear relationship between speed and friction torque when motor worksat high speed．So friction torque has little effect on the motor in high speed range．Butin low speed range，friction torque shows very serious nonlinear characteristics whichresult in the appearance of speed ripple．Upon the PMSM model and the LuGrefriction torque model，this paper combines adaptive control theory and backsteppingde sign method to design backstepping adaptive speed controller and current controllervia introducing the concept of virtual controller．Lyapunov stability theory proves thatthe designed backstepping adaptive controller is stabilized．Simulation analysis is accomplished in this paper．Simulation results show thatthe backstepping adaptive controller makes PMSM more stable at low speed．Basedon theory analysis and simulation research， an experimental setup is built toim plement the backstepping adaptive control strategy．Experimental results show thatthe proposed backstepping adaptive controller satisfies the basic performance，and hassome effect on compensating friction torque．...