Study On The Virtual Test System Of Automobile AMT Electronic Control Unit

The development of Automated Mechanical Transmission (AMT) is very important for lightening drivers' labor intensity, improving vehicle power and economic performance. As an advanced computer simulation technology, virtual test technology can accomplish tests rapidly, shorten developing time and save study expense. A virtual environment can be developed to debug, examine and evaluate ECU'S performance by using the technology, and the system can play an important role in studying and developing the ECU with higher efficiency and lower cost.First, on the basis of system analysis and plan design, a method is given, which constructs AMT Electronic Control Unit virtual test system by using Hardware In the Loop Simulation (HILS). The system consists of data acquisition card, computer, AMT electronic control unit, engine and chassis simulation model.Second, engine's partial velocity characteristics model and universal characteristics model are built The throttle opening is considered as an essential factor to build the model for reflecting the actual working performance of engine. The situation of the throttle opening change is studied, and a simulation method is given to use torque curved surface and vehicle dynamics equation on base of differential approach method. Engine test software is developed for the engine no-load test, variable throttle opening test and throttle step change test. The test data is used to verify the mathematical model. Simulation system of engine characteristics is developed on VC++ platform. In the system, characteristics of engine can be changed with the throttle opening under the control of the software.Third, the optimizing dynamic performance and economic performance shift law are analyzed. An optimal work model of AMT is discussed. Dynamic and economic parameters are deduced and program is developed.Fourth, clutch work model is constructed. The friction work and the starting jerk of clutch are studied. The simulation program is developed, which could calculate the friction work and the starting jerk. The jerk of clutch is studied, and a rule that clutch can be optimizing controlled at every gear is given according to the test result. The rule means much to control clutch.Finally, the AMT Electronic Control Unit Virtual Test System with Windows style Graphics User Interface is developed on the base of above theories. By actual test, AMTVTS can generate the engine speed signal and vehicle speed signal that is necessary for ECU debugging, meanwhile, the signal of the ECU can be collected, analyzed, processed, displayed and saved. And the system can track the ECU working state and dynamically reflect the influence of control rules on vehicle power and economic performance. The system means a great deal to develop AMT ECU and improve the design.