Research On Adaptive Speed Control Algorithm For Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)is widely used in high performance servo control such as in industrial robots due to its high reliability,high power density and simple control.The permanent magnet servo system often exists variable loads and complex operating conditions,causing significant change in inertia and load torque,and it will not reach the requirements of controller if parameters are not changed.Therefore,in order to improve control effect,it is necessary to identify inertia and adjust controller parameters to realize adaptive control.The traditional model reference adaptive identification neglects the influence of viscous friction coefficient and does not affect the inertia and load identification accuracy of small friction servo system,However,for large friction servo system,identification results are fluctuated and difficult to stabilize.So in this paper,a model reference adaptive algorithm considering viscous friction coefficient is proposed to identify mechanical parameters.We can get accurate values of the inertia,load and friction coefficient simultaneously at different speed amplitudes,frequencies and different initial inertia values,improving parameters identification accuracy of large friction servo system.The controller based on backstepping method is composed of kp regulators and other compensators.it can be compensated accurately when parameters are accurate.But in servo system,parameters are unknown or change with operating conditions,so the backstepping controller can not compensate accurately,resulting in large system error or even instability.Therefore,an adaptive backstepping identification algorithm is proposed to correct controller parameters by using identification results to achieve accurate compensation and improve robustness.The traditional adaptive backstepping controller with unrecognized friction coefficient will lead to fluctuations and can not converge to real values for large friction servo system.Thus,an adaptive backstepping identifying friction coefficient is designed to obtain accurate inertia,load and friction coefficient under different speeds,loads and initial inertia values,which has good speed tracking performance by adaptive speed backstepping control.The adaptive speed control algorithm considering friction coefficient can obtain accurate identification values to correct the controller parameters,which has good speed tracking performance.The validity and accuracy are verified by experiments based on the platform using dSPACE DS1103 system.The methods have merits of simple structure,usability and wider application,which is instructive for adaptive current identification.