| Synchronous coordinated control and differential steering are the focus of research on hub-type electric vehicles.In synchronous coordinated control of electric vehicles,response speed and synchronization error among motors are the main performance indexes to measure synchronous coordinated control.This paper aims to improve the problems of large synchronization error and slow response speed among motors in synchronous coordinated control system of six-wheel electric vehicles,in order to improve the response speed of motors,reduce synchronization error among wheels and provide guarantee for smooth running of vehicles.In the synchronous coordinated control system of six-wheel electric vehicle designed in this paper,the motor control mode adds fast super-twist control algorithm based on the traditional vector control,and through fast super-twist control,the speed response speed and anti-interference ability of single-motor can be effectively improved,so that the motor can quickly track the target speed when disturbed,thus reducing the synchronous error and synchronous coordinated response speed of multiple motors.then,BP neural network PID is used to improve the speed compensator of deviation coupling control.In view of the slow convergence speed of traditional BP neural network,additional inertia term is added for optimization,and the synchronous coordination control system of six-wheeled electric vehicle before and after improvement is simulated and analyzed in MATLAB/Simulink software.The simulation results show that the improved synchronous control system of six-wheel electric vehicle has better control performance,the maximum synchronous error between motors is reduced from 27.6r/min to 2.29r/min,the synchronous error after stabilization is reduced from 1r/min to 0.25r/min,and the time to reach stability is reduced from 0.039 s to within 0.01 s,thus achieving the desired effect.Finally,aiming at the existing differential steering technology,the steering control system of six-wheel electric vehicle is established by using Ackermann-Jeantand steering principle,and the motor based on fast super-twisting algorithm is combined with the differential steering model to build a model in MATLAB/Simulink.The simulation results show that this control strategy is feasible,consistent with the expected results and has certain practical value. |
