Design Of Testing System For Automotive Quiescent Current And Wiper Motor

With more and more electronic devices applied in automobiles, electronicdevices not only improve automobile performance dramatically, they also addburden to automotive battery. High quiescent current of electronic devices mayeven result in power loss of battery which will make it unable to start the engine.As a key technical parameter of automotive electronic devices, it is important totest quiescent current of automotive electronic devices. Currently there are fewresearches on testing method for quiescent current from domestic automobilemanufacturers which makes this project research really meaningful. As animportant factor to driving safety in raining days, windshield wipers must also beunder strict quality test.The purpose of this research is to design testing system for automotivequiescent current and testing system for wiper motor. The testing system forautomotive quiescent current is developed to acquire, decode, display andanalyze the test data automatically in real time, with48electronic devices atmost, plus generating and printing evaluation report. The testing system for wipermotor is developed to control the stalls of LIN wiper motor and traditional wipermotor, automatically control the stalls of LIN wiper motor based on rainfallinformation collected by rain sensor, automatically record the number of wipers’scraping actions, control rainfall size, and generate test report.First, the paper introduces the characteristics and test standards for quiescentcurrent, and the basics of LIN protocol. For the testing system of automotivequiescent current, the paper introduces the framework of testing system and theacquisition method of quiescent current data, and focuses on COM (ComponentObject Model) components of SPARTAN data acquisition device, which isresponsible for the communication between system software and acquisitiondevice hardware. The data analysis algorithm is developed based on testingstandards for quiescent current. Four major functional modules of the system,including system control module, data analysis module, report generation andprint module, and additional module, is completed programming, plus thesupporting of up to48measurement channels simultaneously. For the testing system of wiper motor, the paper focuses on the structure and meaning of eachframe in LIN matrix table from LIN wiper motor, completes the firmware andapplication software to achieve the required function of the system. Finally, theoperation process of these two systems and analysis of test results is presented inthe paper.Both systems have been tested and passed by FAW-Volkswagen, achievingrequired functions and having been used in practical field test. The twoautomated testing systems have improved work efficiency dramatically.