Development Of Automobile Intelligent Instrument Based On CAN Bus

The research of Automobile Instruments has acquired great progrcss currentlv with the development of Automobile Engincering . Nowadays , an important resuIt 0f Automobile Instruments is the vehicle information service system internationallv. Meanwhile,Automobile Instruments is during the transition from artiffcial circuiI instrument to digital instrument in OUF country.Howcver,the existing Automobilc Instruments arc far from that of perfectly intelligent service required by USers Of automobile.On the other hand,there is still a gap between the AutomObile Instruments of our country and these on highest level , and the development of the Automobile Instruments is behind the development of automobile obviouslv as well.With the development of science and technology of computer,electronics,CAN—BUS and other subjects which closely relate I()intelligent instruments,especiallv the realization of single—chip micro—controller technology,it is possible to develoD the Automobile Intclligent Instruments(A11),which may cause a basic revolution 0f Automobile Instrument.Many current studies suggest that it is an effective way for the realization of All through the connection of intelligent field devices to autOmation systems by using CAN—BUS with the focus of single chip machine fSCM).Therefore,this study aims to the design of AII based on CAN.BUS,in order t0。mpro"e the accuracy of information.This study designed the general program of AII at first.After the comparison uf the existing types of CAN.BUS,it chose PICl8F458 of SCM,MCP2551 of CAN transceiver of Microchip Company,6N137 of oDtical Isolator,CAN-BUS of BOSCH Company and LCDl602 of LCD MonitOr as the hardware system.Then,this study designed CAN communications hardware circuit. minimum system module and man-machine interface module and SO on,sO as tO carrv。ul a real'time measure on Ihe r"of automobile engine,running speed . the water temperature and the oil pressure . In addition.it analyzed the characteristics of anti。inter;terence for hardware system as well.For software,using special software MPLAB IDE of the P1C to design communication modulc of CAN.BUS.sub—program of A/D and sub—program of LCD.Furthermore,it also conducted lhe analysis on the characteristics of anti—interference for software system. The results of this study show that,the characters of anti.interference.stabilitv and reliability of information for thc All based on CAN.BUS are better than the traditional instruments.Moreover All based on CAN—BUS has simple structure which implies the convenience of practice.