The New Generation Passenger Car Instrumentation Development Based On CAN Bus

Automotive instrumentation is not onlyan important interface to displaythe information ofthe vehicle, but also is an important part for the safe driving.As the development of theautomotive electronic technologyand the emergence of the new energyvehicles, the formerautomotive instrumentation can no longer meet the requirements of the information displayinthe modern vehicle. This paper is the new generation passenger car instrumentation developmentbased on CAN bus which is a new instrumentation made for the new energy vehicles DonfengEQ6110HEVhybrid bus.The paper analyzes the main function of the hybrid bus instrumentation system, which theoverall design of the instrumentation is made based on. In hardware design, two FreescaleMC9S12HZ256 micro-controllers are used as the control core. Seven stepper motors are used toshow the information of the vehicle.An LCD module is used to displaythe energystate of thehybrid power system and the parameters of the engine, motor and the battery.The CANtransceiver PCA82C250 is used to make the instrumentation link into the CAN bus of the vehicle,so that the instrumentation can communicate with theVehicle Control Unit, Motor Control Unit,BatteryManagement Unit and displaythe parameters of these electronic modules. In softwaredesign, the micro-stepping mode and the fuzzycontrol to change the speed of the stepper motorsare used to drive the stepper motors, which makes the stepper motor run more smoothly, quicklyand reduce dither. Stepper Stall Detector module of MC9S12HZ256 is used to make the steppermotor return to zero faster, more accurately. In LCD module, the dynamic displaymethod andmulti-screen displaymethod are used to displaythe energystates and more working parametersof the HEV, which enhances LCD displayvisual effect.The digital filtering method is used inpulse sampling and analog sampling, so that the information obtained bysampling is moreaccurate and reliable. In instrumentation system debugging, a host computer software is made onthe platform of LabVIEW to determine the relationship of the sample value, the real physicalvalue and the steps of the stepper motor rotating; the instrumentation, the HEVhardware-in-loopsimulation system and theVehicle Control Unit are composed of the CAN bus network, whichdebug the CAN function of the instrumentation.The debugging results show that the steppermotor pointers indicate accurately and the CAN network works well.The instrumentation that is developed in the subject has a good compatibility. It can not onlyuse in the HEVbus, but it can also use in other buses by changing some hardware and makingsome changes of the system software.