| With the fast development of electronics and computer technologies, the electronic control system on vehicles in China is improved better and better. For an instance, the traditional electric meters are replaced by digital and intelligent instruments. In order to develop those apparatuses, we must improve the test and experiment approaches. Based on analysis and research on the meters used on vehicles, referred to the developing trend of test technique in the world, an advanced test technology is developed in this thesis.On the basis of research and analysis on the structure and test technique of the speedometers and engine tachometers, a new test system is developed based on a new test principle. Using this test system, users could edit and input operation parameters and get the operating information by the USB communication and data display subsystems. In order to improve the veracity and high speed of the signal output, we developed a MCU application system to communicate with users through USB interface.The developed test system has high reliability and application value. By using this system, we could finish more and more kinds of speedometers and engine tachometers' reliability experiments automatically in time, some scientific test modes and identify standard could be provided to experiment department, factories could improved their products' quality, and experiment workers could establish perfect experiment modes and work condition standards. In this thesis, we accomplished the following works: the development of intellective speedometer and engine tachometer's reliability experiment station; utilizing software to select and setup the meter's operating conditions; the designation and application of data communication interface module; data processing; finishing condition experiment by computer, and so on.The following tasks have been accomplished in this thesis:1. The summarizeFirstly, the introduction of the source of the project, the meters used on the vehicles and the development of the experiment technique on them. Secondly , the main task on the project.In the life test of the speedometers and engine tachometers, the way we used to give the pulse signal input imitating that from the sensor adjusted by hand is backward ;Otherwise, the testing table by introduced can't meet the need of the complicated and diversified operation conditions. So it's the urgent need for electric test department in the FAW TC to develop the testing table which can do the life test experiments automatically. By the analysis of the development status of the experiment technique for the meters used on vehicles, we show the functions and the compose of the system we designed, and determine the tasks we will do: the development of user system and the development of application system.2. The analysis of the common meters' structure and principle in vehiclesWe analyzed the structure of the common combination meters and their sensors, referred to the measurement methods and controlling principles of the speedometers and engine tachometers' experiments before, utilized modern computer technology to design digital frequency conversion scan circuit, which is simple but effective. At the same time, we analyzed the structures of another three meters, and found one method by using changing D/A output to control electronic load current, by which we can simulate meter sensor to test the meter. Therefore we establish the foundation for developing all the test station of five kinds of combination meters in the future. 3. The development of user systemThe user system is a user-oriented experiment system, whose processor is 486DELL micro computer and software development environment is Borland C++ Builder. User system is able to setup operation conditions, and send frequency values and controlling commands to application system by USB interface according to the operation conditions. Interface designing, operation of condition files, the condition setting, data communication and conditions displaying... |
PDF Full Text Request