Study On Control Strategy Of Turntable Permanent Magnet Synchronous Motor For Calibration Of The Inertial Units

As an important carrier for inertial component calibration and vehicle tracking target,servo turntable is playing an irreplaceable role in aerospace field,and its dynamic and static performance directly affects the result of application.As an important part of the turntable system,Permanent Magnet Synchronous Motor servo controller is widely used for its superior dynamic tracking performance.However,in the actual application of the motor,the motor control accuracy and responsiveness are affected by factors such as parameter mismatch,observer performance and load disturbance,etc.So,how to overcome these unfavorable factors has become a hot research topic at home and abroad.In this paper,we take the servo turntable as the background,and make a more in-depth study on motor parameter identification,stator flux observation,and robust control for several problems of the above PMSM control,respectively.Firstly,permanent magnet synchronous motor parameter model is subject to parameter mismatches during actual operation,this paper introduces uncertain variables such as electrical parameter regression on the basis of the approximate ideal mathematical model to construct a motor model under parameter mismatch,which provides a theoretical basis for the design of parameter identification,flux observer and robust controller in the later paper.Then,in this paper,an identification algorithm based on model reference adaptive control is proposed to reduce the impact of parameter mismatch on system performance.It uses Popov’s super stability principle to design the adaptive rate to make the estimated parameters close to the nominal value on the basis of the motor mismatch model,and realizes the online identification of multiple parameters such as PMSM resistance,inductance and flux in steps,avoiding the under-ranking problem of multiple parameters identified simultaneously.The modeling simulation analysis verify the feasibility of the proposed method.Next,a second-order sliding-mode adaptive flux observer is proposed based on the concept of motor effective flux to address the drawback of large pulsation of the first-order sliding-mode flux observation.The observer uses the theory of super-twisting algorithm to construct a second-order observer model based on current error estimation,and also uses the relationship between the effective flux and the stator flux to accurately obtain the estimated value of the stator flux,which improves the accuracy of the flux estimation and realizes the stability of the PMSM without position sensor control.Finally,theH_∞output feedback controller is designed using the idea of static decoupling to transform the nonlinear motor model into a linear mode in this paper.The external disturbance inputs of the controller are the motor speed and load torque,and establishes the relationship between the weighting function and the system performance index to realize the PMSM-H_∞speed control,which reduces the dependence of the traditional PI control on adjusting the controller parameters and improves the system’s anti-load disturbance capability and robustness of the system.Theoretical analysis and simulation results verify the correctness of the proposed method.