Design Of The Fault Diagnosis For Automobiles System Based On Radio Frequency Communication

With the rapid development of our society, the electron degree of automobiles is becoming more and more deeply. The complex of the automobiles has brought much inconvenience to people for maintaining and repairing them. Considering the complexity of the fault diagnosis apparatus of automobiles in operation, the essay developed a new kind of fault diagnosis system based on radio frequency technique.The system designed in this paper is aimed to simplify the fault diagnosis apparatus used in our life. For the system, most users can operate it skillful without knowing specialized knowledge. The system is based on self diagnosis system OBD-II. It uses KWP2000 protocol to communication with OBD-II. It reads the status information of the engines'in real time firstly, then sends these messages to the repair terminal by wireless method. At the repair center, the fault messages will be displayed distinctly. So the repairer can fix the position of the fault easily. The system is an attempt innovation, which combine the fault diagnosis of automobiles with the short-distance wireless communication.In this paper, we first analyze and compare some wireless communication techniques popularizing today, and choose the radio frequency technique as the communication method. Then we choose the nRF905 chip as the core chip of the system basing on a lot of performance indexes. Secondly, we design the whole system, the hardware and the software of the system are described in details. We also develop the wireless communication program. The key point of the research is the realization of the radio frequency communication under the inset circumstance. We realize it by making SCM control the nRF905 in the paper. The results of the simulation show that, the system designed in this paper meets the requirements of the long distance fault diagnosis for automobiles in wireless method, it has perfect performance and the operability is high. So, the system will have a wide application foreground definitely.