Research And Experimental Analysis Of Onboard Test System For Medium-sized AMT Commercial City Bus

Nowdays the commercial buses in china mainly can be divided into large andmedium-sized commercial buses, light commercial passenger cars and minicommercial vehicles, and the large and medium-sized buses is mainly used as coachbuses and city bus. In fact, the city bus often runs at a low speed and need to be staredfrequently, the drivers have to shift transmission frequently, so they sustain moreundoubted following labor intensity. As the comfort requirements of large andmedium-sized commercial bus is lower than the passenger cars, the AMT whichequips with extra automatic shifting system based on the traditional manual gear boxand uses computer-control actuator to replace manpower to complete the shift andclutch operation in order to achieve the automatic speed control. In virtue of theexisting transmission production line to manufacture AMT conform to China’snational conditions, assembling automated mechanical transmission in large andmedium-sized commercial bus (AMT) is one of the best choices. But now AMT alsodoes not have the capability of industrialization, many automobile companies onlyexploited some sample vehicles with AMT, and the performance of AMT is still notperfect. In different stages of the AMT research, researcher requires a large amount oftest data collection as the base.According to the need of vehicle test system, this paper used a prototype of citypublic transportation vehicle equipped with AMT, based on the embedded PC104,combined the LabVIEW graphical programming language, established a system ofvehicle testing, collected and analysed the parameters that affecting the performanceof AMT, compared the AMT performance of prototype, in order to establish thefoundation of further improvement and development in AMT research.This paper expounded the principle of AMT, and obtained the influence to theperformance of AMT by engine speed, input shaft speed, speed, clutch stroke andsolar term door opening degree and other parameters from the combination of controland schedule of clutch, also discussed the shift quality and friction work. Bycollecting the basic data, this paper classified the types and sources of test parameters;then according to the test system,and meet the demand of anti vibration, light weight,small size, select the embedded PC104to develop the test system; after introducingPC104bus, the overall design of the test system should be based on PC104bus, and then introduced the selection and configuration of system hardware, including thesensors, YanHua PC104board, YanHua data acquisition card, counting card, storagefacilities and power supply, established a hardware system based on embedded PCcore.This paper introduced the process of software design and the functions of eachmodule, transplanted Windows XP Embedded operating system into the embedded PC.Through the introduction of LabVIEW virtual instrument software platform and thecharacteristics of LabVIEW data acquisition, the author based on the modularizeddesign and used LabVIEW virtual instrument software platform to design the vehiclesystem software, ultimately all the parameter information can display, save andanalyze collected by data acquisition card and counting cards at real time processing.This paper finally used the vehicle test system to test on a commercial vehicle,and analyzed the test data, the test results show that the test system can work stablyand the performance of AMT works well.