A Study On Control Strategy Of Metal Pushing V-Belt CVT With Wet-Clutch

The continuously variable transmission (CVT) is an ideal transmission form for economical automobiles. The metal pushing V-belt continuously variable transmission is well accept and gets rapid development for its advantages, such as simple and compact structure, easy operation and excellent performance. This technology is also selected as one of the key research projects in China during the ninth five-year-plan. The thesis mainly focuses on the control system development and control strategy research of metal pushing V-belt CVT, and the following work have been described:1. The developing history, system constitution, and working principle of the metal pushing V-belt CVT are systematically reviewed based on the summary of various references in home and abroad. The feature and application of the metal pushing V-belt CVT are also analyzed2. The models for engine system and EQ6480 bus equipped with metal pushing V-belt CVT are established, the performance curve fitting of EQ491 engine is made, simulation analyses are followed so as to confirm the effectiveness of the control scheme.3. To start vehicle rapidly and smoothly, a kind of method based on fuzzy technique to control the engaging-pressure of wet-clutch has been established. Fuzzy control will achieve the following advantages: the engine can be controlled to be operated steadily during lower speed and the starting noise can be reduced.4. For the purpose to realize the control strategy, hardware design for sensors and CPU, signal processing, circuit layout and the control signal output interface.5. This paper suggests a new sort of method to emulate automobile electric control system. This method can realize emulator debug and real-time adjustment of the system. The communication with the network and long distance in auto electronic control system has been roughly discussed. For the purpose to realize the control strategy, software design and code compiling are completed. Optional control of transmission ratio and system parameters is realized under different operation condition and different control modes.6. According to the results of testing and dynamic simulation, the performance of CVT and MT for starting, accelerating and different conditions of the vehicle has been compared.7. In the end of this thesis, the main conclusions are given and further research work needed to do is indicated.