MPC For Dual-Motor Torque Synchronization System Based On Quadratic Form Cost Function

The dual-motor gear transmission system is widely used in heavy-duty industrial applications,such as track traction,cement rotary and paper printing.Factors,such as motor parameters differences and gear mesh misalignment,are likely to cause the imbalance of motor output torques,which may affect the control accuracy and reliability of the transmission system.In severe cases,accidents like broken shafts may occur.Therefore,it is of great practical significance to carry out in-depth research on multi-motor synchronous control strategy and improve the synchronous control performance of dual-motor system.After the proposed cross-coupling control strategy,the control structure of dual-motor torque synchronization system are difficult to improve,but the finite control set model predictive control(FCS-MPC)is an advanced control algorithm with advantages of fast dynamics response and easy realization of system multi-target control,so it is suitable to be applied in the dual-motor synchronous control system to solve the optimization problem of the torque synchronization control target.In the multi-motor system FCS-MPC,the tuning of weight factors in the weighted sum cost function(WSCF)is becoming complex when the number of motors increases.Based on the unified model of a dual-motor torque synchronization system,this paper replaced the WSCF with a quadratic form cost function(QFCF),thereby,the tuning of the three weight factors was converted into the solving of a weight factor matrix.The Lyapunov stability of system can be guaranteed by applying the weight factor matrix obtained by the offline solution algorithm to the QFCF,so the errors can be guaranteed to converge in the continuous control periods.The control strategy proposed in this paper is experimentally verified on the experimental platform of gear-drive dual-motor torque synchronous control system,and to be compared with the WSCF FCS-MPC.The results of steady-state tracking experiments show that,under the control of QFCF FCS-MPC,the tracking error of each motor and synchronization error have good convergence,the torque synchronization control performance is greatly improved,and the tracking control performance is also improved.The results of dynamic tracking experiments show that both algorithms can guarantee the torque synchronization performance during the dynamic adjustment process of the system,but the QFCF FCS-MPC has better dynamic response capability for load mutation.This paper proves theoretically and experimentally that the QFCF FCS-MPC algorithm can ensure the tracking performance of each motor,meanwhile,it can greatly improve the torque synchronization performance.Furthermore,the control strategy proposed in this paper provides the possibility to expand to multi-motor system.