Study On Heavy Duty Commercial Vehicle Automated Mechanical Transmission(AMT) Test Technology

In our country, commercial vehicles include heavy-duty commercial vehicles, middle-duty commercial vehicles, light-duty commercial vehicles and mini commercial vehicles. Heavy-duty commercial vehicles market in China has been growing up rapidly in these years. With the increase of the fuel price, heavier emissions regulations, continued pressure on operating costs, increasing traffic congestion, and a shortage of skilled drivers, these changes will take place in the engine, the exhaust gas treatment system, and the transmission on vehicles, especially middle-duty and heavy-duty commercial vehicles.Combined with the national 863 project- Research and Development of AMT for Heavy-duty Commercial Vehicle, this paper has researched on there aspects as follows:1 In allusion to huge size, single function, low degree of accuracy and low stability of test system for vehicle performance at the present time and according to the requirement of vehicle performance road test, performance test system for heavy duty commercial vehicle based on the dSPACE real-time simulation system is developed, and hill-start test and acceleration test for heavy duty commercial vehicle are carried out. Test results will provide a reference for AMT development.2 Based on analysis of kinetics of transmission system and shifting process, shift schedule for heavy duty commercial vehicle is proposed and modeling and simulation of transmission system is carried out. Simulation results are compared with test results, then the accuracy of the simulation system and shift schedule are validated.3 According to the requirement of comprehensive performance test bench for AMT, different loading projects are compared and analyzed, and design thinking of comprehensive performance test bench for AMT is determined. At last, the whole scheme of comprehensive performance test bench for AMT has been designed. It lays a hardware foundation for comprehensive performance test bench for AMT.4 Transmission parts of comprehensive performance test bench for AMT are analyzed. Parameters design of large inertia flywheel sets are completed based on simulation at different load. Functions of comprehensive performance test bench for AMT are analyzed. It shows that load requirement at different load, ramp, gear can be simulated. It lays a hardware foundation for comprehensive performance test bench for AMT.