Research On Steer-by-Wire Control System Based On MPC5744P

Steering-by-Wire(SBW)is the future development direction of automotive steering systems.With the rapid development of automotive electronics,more and more researchers are devoting themselves to research on related technologies of steering-by-wire.Compared with traditional steering systems,wire-controlled steering has many advantages: it removes the steering column to avoid injury to the driver in an accident;the road feel is adjustable to improve the driver’s experience in harsh road conditions;energy-saving and environmental protection,eliminating the pollution caused by hydraulic power assistance;It is highly expandable,and is a compatible interface for the future development of unmanned driving.The key technology of steer-by-wire is mainly in the hands of foreign companies,and the domestic research on automotive forward-looking technology has started relatively slowly.Therefore,the research on steer-by-wire is of necessary significance.This article aims to study a complete set of steer-by-wire control system,and solve the problems of domestic steer-by-wire system with poor safety,large ECU volume,unfriendly interaction,and torque pulsation on the steering wheel,and set up a bench for experiments.The system includes hardware,embedded software,algorithms,and upper computer.The hardware part includes six parts: power supply circuit,main control circuit,drive circuit,CAN communication circuit,torque sensor circuit,and resolver sensor circuit.The main chip meets the ASIL-D standard and is designed for redundancy.The main control chip is MPC5744 P from NXP.The peripheral circuit design is carried out around the MCU;the power management chip is selected from NXP’s MC33907,which integrates voltage stabilization and CAN communication functions,and the relevant parameters of the chip can be configured through SPI communication;the pre-drive chip is selected from NXP’s threephase without The special chip MC34GD3000 for brush motor can drive 6 MOSFETs.The embedded software part adopts a layered architecture for software development to realize the basic functions and safety protection of steer-by-wire,including steer-by-wire,automatic correction,±540° electric lock,torque feedback,CAN communication,and voltage protection,Current protection,temperature protection;Road sense motor adopts FOC control mode;The algorithm part includes the adaptation and torque feedback state machine algorithm of the dual closed-loop PID control on the brushless motor.The algorithm is simulated with the help of Matlab tools,and the parameters are calibrated in combination with the experimental results;the host computer displays the main parameters of the system,Assisting algorithm parameter debugging.It is verified by the experiment of setting up a bench that the steering mechanism of the system has a fast response speed and a small torque fluctuation range..The system can well realize the function of the wire-controlled steering control system,replacing the traditional mechanical structure between the steering wheel and the steering mechanism through electrical signals.The system functions reach the standard,the hardware is reliable,the software is stable,and the system is safe,which can provide a certain reference value for the researchers of other steer-by-wire systems.