Design And Implementation Of Real-time Diagnosis System For Automobile Equipment Based On Android

In recent years,the automobile industry has grown very fast.From 2016,the China's automobile sales volume is more that 27 million each year and more families have private cars.Consumers have higher and higher requirements for the driving safety of vehicles.The traditional fault indicator and vehicle diagnosis system of in factory can not meet the requirements of on-board real-time diagnosis.This paper focuses on the design and implementation of real-time vehicle diagnosis software system,the main work listed as below:1.Analyzed the proposed requirements,the main functions of the proposed system include:vehicle real-time data collection,data real-time processing and diagnosis,vehicle equipment management,real-time alarm,local data storage,remote data transmission and other functions.For the proposed system performance,data collection is required to be triggered once per second.2.In order to solve the real-time problem of the system,the multi process parallel processing design is adopted.The system task is divided into user interaction process and background service process.This design enables the system to achieve the background service to collect and process data every second,and the user interface can smoothly display the relevant main parameters and diagnosis results.3.The main interface of human-computer interaction shows the data of power battery,motor,DC voltage reduction module,oil pump,air pump,and overall vehicle data,such as vehicle speed,gear,mileage,etc.The equipment interface distinguishes power system,battery system,charging system and other equipment for status display.In order to solve the problem that the user discovers the abnormal situation of the vehicle in time,all interfaces will prompt the alarm,and the real-time alarm and historical alarm can be viewed in the alarm list.In order to improve the display effect,the human-computer interface is implemented by using the way of custom control.In order to adjust the interface data quickly,the human-computer interaction process will load the interface dynamically during initialization.4.In order to solve the needs of high-speed and large amount of data collection and data processing,the background service process adopts the multi-threaded design method,and distinguishes four main modules:data collection,data processing and analysis,data storage and data transmission.The data acquisition module adopts asynchronous mode to collect the vehicle controller,motor controller,battery management system,three in one controller and vehicle charger in real time through CAN bus.The collected data is calculated and analyzed by the data processing and diagnosis module,and then sent to the human-computer interaction process through the broadcast.In addition to the basic data communication,the data transmission service designs and realizes the function of data disconnection and continuous transmission.5.In order to cooperate with the main functions of the system software,the configuration database mainly includes the parameter table of the calculation method,the can analysis table of the can analysis formula and the corresponding relationship table.A relatively independent design method of business calculation and software is provided,which can upgrade and adjust the calculation method without modifying the software code.6.In order to solve the problem of system test,the laboratory test tool running under win10 is written in Python language.This tool can simulate the data transmission of CAN node,modify the transmission frequency of CAN node,provide a personal computer interface,and modify the parameters on CAN bus through the interface.Using the computer running the test tool and two can to Bluetooth modules,the test environment is built and the system function and performance are tested.All the above items have been tested in the lab,and the system meets the requirements.The performance of data collection and processing is about 460ms,which exceeds the requirement.Meanwhile,the average time of power on is about 25.5s to meet the requirement.The performance of the system can meet the requirements of real-time analysis of vehicle and equipment status.The design of the system is flexible,which greatly reduces the time of later product optimization.