The Research And Development Of Passenger Car Electronic Control System Based On Controller Area Network

Automobile electronic technology has come into a new stage on which the control system is integrated,messages are shared and functions are intelligent. In allusion to passenger car electronic control system now,we design the new style of passenger car electronic control system based on CAN bus technology,intelligent detection technology and micro-computer control technology.The system changed the control mode of passenger cars and the structure of traditional instrumentations;carry out the data concentrated detection,transmission,controlling and data sharing.Also,it can be easy to expand functions,reduce wiring harness, improveits maintainability and security,enhance the system functions.This paper analyses and discusses the developing situation and direction of car's network technology.on the base of In-depth studying of CAN bus technology,passenger car electronic control system and the function requirement of car's electric appliance,we can use CAN bus to transmit data instead of traditional wiring harness and design passenger car instrument panel system and fore-and-aft I/O control unit based on CAN bus.The instrument panel has some main functions.it adopts the PIC18F8585 serieses Single Chip Micyoco which includes Enhanced Controller Area Network(ECAN) module as center controller,using TJA1040 CAN bus drive for transmit messages ,exchanging messages with MC33970 step motor driver to drive step motor to display parameters real-time:vehicle speed,engine rotate speed,cooling fluid temperature,oil pressure,oil capacity,voltage,air pressure,driving LCD to display mileage,time and warning messages,turning LCD screen by key-press,controlling LED indicator light to show breakdown of electric apparatus and state messages.I/O control unit carries out detecting , transmitting and controlling electric apparatus messages.The module of message output diagnoses is used to detect different data,such as analog quantity of voltage and air pressure,digital quantity of car lamp and windscreen wiper and vehicle speed the frequency signal.It can centralized dispose the dispersive messages.Then, it controls relays and DC machine to execute different functions and transmit data to instrument panel by CAN bus to carry out data sharing.The system has been tested on-line and emulated using computer,and the result argued that general performance of this system accorded with the anticipant purpose and request,and it also establishes foundation for the farther improvement and perfecting.