Design And Development Of Vehicle Exhaust Testing System Under ASM

The theory, technology and application of vehicle exhaust measurement system under ASM are researched theoretically and experimentally in this article. The results are of theoretic significance and practical value in applied engineering for exhaust measurement system of in-use vehicle.According to the requirement of vehicle exhaust measurement under ASM, The scheme of vehicles exhaust testing system under ASM is constructed. The system which is on the basis of AHS-ELP300 dynamometer and industrial controlled computer, realizes vehicle mode controlling and exhaust pollutants testing.Based on the analysis of the performance of eddy current dynamometer and ASM mode controlling requirement, the dynamometer torque controller of ASM is designed and developed based on P-Fuzzy-PI compound control. P-Fuzzy-PI compound controller has not only good dynamic and homeostatic capability but also good robustness, which solves the control problems aroused by time-varying and nonlinear parameters of air cooling eddy current dynamometer. The basic ideal and whole project of mode torque controlling of ASM, fuzzy control algorithm, design of input trochoid in the acceleration stage of torque and velocity,The software system of ASM vehicle exhaust pollutants testing is developed by adopting the associative method of two high program languages of LabVIEW and Visual C++, which includes system beaching module, calibration module, data acquisition module, database development module, serial communication module, report generation module and etc.The mode controlling experiment, system repeatability experiment and exhaust contrast experiment under different modes is carried out. The exhaust contrast experiment results under different modes shows testing mode has an effect on exhaust measurement results noticeably, and mode controlling is important for the whole testing system. Mode controlling experiment results show torque controller realizes good control of loading torque, vehicle speed controlled by driver easily and meets the needs of testing mode controlling of ASM. System repeatability experiment results show that systemic repeatability is good and systemic project is reasonable and the overall design is feasible.