Remote Diagnosis Instrument For Automobile Based On Bluetooth Wireless Communication Technique

With the rapid development and widespread popularization of cars,more and morepeople begin to own their cars.The maintenance and repairing of cars are becoming more and more important.When car is in use process,there will inevitably be a failure,but since the vast majority of owners do not understand the car,it does not can be timely treated.Thus must go to special car repair shop.Additionally,when the vehicle is traveling in the suburbs or long-distance road failure,it will bring a lot of trouble.Moreover,when the vehicle has abnormal electronic circuit and the failure of the electronic control unit(ECU),although it can still drive,it has buried a hidden danger for the safety of the vehicle.In order to solve the above problems,a portable diagnostic instrument is developed in this thesis to help car owners to detect vehicle faults conveniently for ensuring the safety of traffic.In this thesis,the remote diagnosis instrument based on Bluetooth wireless communication technique is developed,and the main work is as follows:(1)The bus diagnostic technique is introduced,including K bus,CAN bus and its corresponding physical layer,data link layer,and application layer protocol.(2)The overall design of the vehicle remote diagnosis instrument system is carried out.On this basis,the hardware circuit design is completed,including power module,ignition start detection,CAN transceiver,K bus module,Bluetooth module,MCU module,memory module,ACC detection module,and so on.(3)The design and implementation of embedded software system for vehicle remote diagnosis is made,mainly including ignition and flameout detection,OBD protocol judgement,PID support list,OBD chassis number,OBD fault code,driving data collection,OBD fault code self-collection,OBD vehicle data collection,etc.(4)The function and performance tests of the vehicle remote diagnosis instrument are done,including the constant temperature test,the power change test,the real car test,etc.The test results show that the system function and performance meet the requirement of the system.Automobile remote diagnose analyzer in this thesis use mobile phone as the display and control terminal,and the diagnostic command,and vehicle fault,state are displayed.It has the ability of remote diagnosis and traffic monitoring data for the most of the vehicle dynamic system.Moreover,it has the features such as usage convenient,low cost,high reliability,and versatility.