Research On Motor Control Of Vehicle Lane Keeping Assist System

With the development of automotive technology,the speed of the car is promoted by the continuous improvement of power.Also,the incidence of traffic accidents is constantly increasing.According to statistics,44% of the traffic accidents are caused by the deviation of the vehicle from the lane.The Lane Keeping Assist Systems can effectively correct driver's improper operation and assist driver in dealing with emergencies,which has very high research prospects.When the vehicle has been or tend to deviate from the lane,and the driver does not correct the intention,the LKAS can take the initiative to control the operation of the EPS motor,and correct the direction of the vehicle,inhibit the vehicle lane deviation tendency.So that the vehicle can quickly returned to the lane,and maintain the safety driving track.Based on the dSPACE platform,the control strategy of permanent magnet synchronous motor(PMSM)for LKAS is studied.dSPACE hardware-in-loop simulation platform has a very good fast and real-time.Compared to hand-written procedures,SIMULINK-based block diagram of the control can save a lot of time.And the experiment is reproducible,greatly shortening the experimental cycle.In this paper,firstly,the principle and mathematical model of permanent magnet synchronous motor are introduced.The vector control principle,coordinate transformation method and SVPWM wave modulation method and realization process of permanent magnet synchronous motor are emphatically studied.Then the simulation model of PMSM vector control based on MATLAB / SIMULINK is established,and the control algorithm is verified.Then,dSPACE is used as the platform,and the driving circuit is designed and the driver used in this experiment is made.Which includes power supply circuit,drive circuit,main circuit and protection circuit,current sampling circuit and dSPACE I / O interface circuit.Combined with dSPACE and the driver,a PMSM hardware simulation platform is built.The experimental results obtained on the platform are compared with the simulation results,and the effect of the control algorithm is verified.At the end of this paper,the principle and the control algorithm of LKAS is analyzed.Then,the joint simulation model of CarSim and SIMULINK is established according to the parameters measured by Honda City,and the vector control model of permanent magnet synchronous motor is established.The motor is used to revise the vehicle trajectory,so that the driving direction can follow the curvature of the lane or return to the original lane.And set up two different conditions,to verify the effect of the model built.