The Study Of General Automatic Electronic R&D Platform

During the long time steering period, vehicle is in various kinds of roadconditions and suffers different kind of stresses, just like external condition stress,inner function stress, movement stress and so on. At the same time, due to thedifference of structures and use conditions which include road condition, climate,use intention, steering condition and so on, vehicle technical status parameter ofassembly and accessory will take place changes with different regulation andintention. All these conditions will make the vehicle function parameter moreinferior, as a result, the vehicle performance will reduce and even take placemalfunction. Therefore, relevant stakeout survey system must be set up so as toestimate the vehicle technical conditions, find out the malfunction might occurbetween current stated term and next inspection, confirm the available varieties oftechnical condition parameter, adopt relevant measure to avoid the malfunction andensure the vehicle performance.According to this purpose, people put forward the concept of vehicle real timestakeout control system and develop various kind of instrument like vehiclestakeout survey apparatus and vehicle examination line to analyze vehicleperformance with the use of modern electronic technique, computer technique andsensor technique. The study of the Research and Development Platform ofElectronic General Technique for Vehicle comes forth under this background.The system of research and development platform of electronic generaltechnique is a kind of SCM control digital, automatic, intellectualized stakeoutsurvey equipment in vehicle. The R&D platform of electronic general techniquecan be set up to stakeout the vehicle performance in different band and type vehicleconveniently so that the drivers can realize the steering status and eliminate themalfunction occurred. At same time, the system can memorize all kind of drivedata to be convenient for vehicle long period data stakeout and performanceanalysis which achieves energy reducing and safety driving.This paper is established in SCM system and develops the R&D platform ofelectronic general technique. The main research content contains:1. Collectivity scheme design of R&D platform of electronicgeneral techniqueAccording to Human-Vehicle Engineering and Automotive Electronics, designprinciple of R&D platform of electronic general technique is put forward, which isinformation display system must be simple and direct, information provided todriver must be correct and abundant, system must be reliable, system must be setup on different kind of vehicle conveniently, the collected data must be memorizedand communicated with PC conveniently, the capability of anti-jamming must befine.According to the analysis of many input parameters from sensor during the driveprocess, the parameter is divided to three kinds: 8-route simulation parameter,vehicle speed and rotate speed, alarm parameter,dynamo malfunction parameter,switch control parameter. P89C668 SCM is chosen to be the CPU, while CANassemble line is chosen to be the locale assemble line.Whole system is divided to two parts: control node and data input node. Datainput node takes charge collection of data the system needs and sends the data tocontrol node. According to the sensors of engine rotate speed, vehicle fuel pressure,driving speed, cooling water temperature, the data collection node unit collects datato transform the simulation signal to the signal the processor can identify with themeasure of wave filtration,A/D switch and inputs the SCM. Control node is theinformation terminal of whole system. Its task is to accomplish the data memory,display and adjust the parameter not measure up.2. Hardware design of R&D platform of electronic generaltechniqueAccording to R&D platform of electronic general technique working principle,the function requirement of ECU is put forward. In term of the method ofmodularization and structurization, ECU hardware is designed. In the course ofdesign, the anti-jamming treatment is adequately considered.According to function requirement, ECU hardware collectivity design schemeis put forward. ECU hardware consists of CPU system, energizing circuit, LCD,data memory system, input interface circuit, communication circuit and CANassemble line. ECU determines the vehicle status and emits control dictateaccording to the input parameter and established control strategy. In CPU system,P89C668 is chosen. There is an 11.0592MHz crystal oscillator in clock circuitwhile MAX813 is introduced in reset circuit. Energizing circuit changes 24Velectrical source into different power supply for peripherals. In LCD system,240128A is chosen, while control word is input and data is controlled to display byT6963C. AT24C512 is chosen to be ROM. Input interface circuit include speedsignal shaping circuit and switch signal shaping circuit, it can change input signalinto electrical signal that can identified by CPU. Communication circuit includeCAN and RS232, it fulfill data interchange and information sharing between ECUand other electronic equipment.3. Software design of R&D platform of electronic generaltechniqueBased on the theory of R&D platform of electronic general technique, thefunction requirement of ECU is put forward. We accomplish the design andresearch of ECU software according to the character and specialty of chose ECUhardware.Considering the data traffic of module as well as real time,reliability,theoptimizing of control arithmetic and whole system executive validity, the softwaredesign is adopted the ideology of real time task management. Whole softwaredivides to several different task modules and different PRI according to differentfunctions. The whole system attempers the task modules in order to utilize SCMresource and improve real time character of whole system.The software design is compiled with C51 Program Language. The wholesoftware is divided to main program and several minor programs with structureprogram design method. Function modules are composed with one or several minorprogram with independent functions and low coupling degree. ECU software consistsof several modules like initialization module, driving speed mileage measuremodule, voltage measure module, LCD module, CAN communication module andso on. According to these modules, system achieves control strategy, creates controlsignal and actualizes failure diagnosis and analysis.4. Anti-jamming design of R&D platform of electronic generaltechniqueSystem interfere mainly consists of space interfere, process routeway interfere,power supply interfere. According to the interfering character analysis,anti-jamming principle is designed: restrain yawp coupling and reduce circuitsensitive degree to interfering signal;enhance anti-jamming redundant measureproperly;eliminate interfere signal before entering into SCM.