Research And Implementation Of An Automotive Diagnosis System Based On Android Smartphone

From the beginning of the1950s, electronic technology began to be applied to the automotive industry, automotive electronic control system architecture has become increasingly complex. We enjoy the continuously improving of the automobile’s dynamic performance and safety performance which is the electronic control system brings to us, while we should also face some new issues, such as the much more type of the fault, the increasing possibility of fault occurred, and the more difficult to diagnose the fault type and occurrence location. At present, the diagnosis of fault is more dependent on the electronic, computerized professional diagnosis system, therefore automotive fault diagnosis instruments has become an essential equipment in the process of diagnosis, and its demand is also growing. For the shortcomings and deficiencies of the existing diagnostic instruments, and combined with the Android smartphone having a huge amount of users and increasingly powerful computing capability, support rich hardware resources, simple and intuitive graphical user interface, quick and easy access to the Internet, and so on, this paper design and implement an automotive diagnostic system based on Android smartphone.The diagnostic system researched and implemented in this paper, communicates with the automotive OBD systems by ELM327which is an generic OBD-II diagnostic interface, to read the automobile’s real-time operating parameters and fault parameters. The system has high versatility, which can be applicable to most of the models. Through this system, the owner can view the car’s real-time information and the garage around him, apply for remote fault diagnosis and roadside assistance, and also can manage information about gas and maintenance.To achieve this system, the main research works in this paper are as follows: (1).The primary task of the paper is the vehicle traveling data acquisition and uploading. First is the methods of obtaining the vehicle acceleration and driving direction through the smartphone’s sensors; next is the process of the automotive OBD system’s data acquisition, and considering the real-time and redundancy, designing a data dynamic collection strategy; and last is the data uploading, adopting the method of MQTT push to upload data in real-time, and designing a new data storage format for manually uploading to reduce storage space.(2).This paper makes specific analysis on keys points of the system. According to the vehicle data, this paper lays emphasis on fault diagnosis, oil consumption analysis and forewarning analysis of dangerous driving to better serve drivers. Moreover, the network transmission of data also researched in this paper, including parsing JSON formatted interactive data, using double MD5encryption to ensure the transport security of sensitive data such as user passwords, introducing asynchronous network transmission mechanism to ensure the time-consuming network data transfer operations execute normally.(3).Design and implement an automotive diagnosis system based on Android smartphones. Research is mainly focused on the design of the overall structure, the design of the function modules and the design of data storage solution. According to the design of the function modules, this paper analyzes the design of system interface and the implementation of the corresponding function of each function module in detail.