Process Control Study On Clutch Of Commercial Vehicle With AMT During Starting

Due to automatic mechanical transmission is made by transforming original manualtransmission, AMT keeps a lot of advantages of manual transmission which include hightransmission efficiency, low cost of production and maintenance, simple structure and achievedreliability. Moreover, because of the big productive scale and wide application of manualtransmissions in the large China’s market of commercial vehicle, vigorously develop technologyof AMT is suitable for China’s situation. There are many key problems of technology research ofAMT need to be solved. One of the problems is the automatic control technology of clutch duringvehicle starting. The control performance of clutch has major influence on starting quality ofvehicle and service life of clutch friction plate. In this thesis, the research object is a commercialpassenger car with AMT, and the main work is the study on automatic control strategy of clutch.The research contents are shown as follows:(1)The research on characteristics of clutch is analyzed in detail, which includes loadcharacteristic, separation characteristic and torque characteristic. Additionally, a mathematicalmodel of load deformation for diaphragm spring is presented. Based on the analysis ofcharacteristics of clutch, a new type of electric-hydraulic control and gas power assistanceautomatic control system for clutch is designed and developed, and then a mathematical model ofclutch automatic control system is established.(2) A dynamic mathematical model of clutch during starting and a force model of vehicle areestablished. The evaluation index which includes shock extent and slipping power is analyzed, andthe major control parameters of clutch are selected. At the same time, the control strategy of speedcontrol for clutch engagement based on bi-fuzzy control is developed, and a fuzzy controller isdesigned.(3) According to the analysis of the characteristics of the engine, a steady-state model ofengine is presented. Meanwhile, the steady-state model of engine is tested. Finally, a fuzzycontroller of engine speed during starting based on the principle of constant engine speed in partprocess is developed.(4) An integrated control simulation model of vehicle with AMT during starting is establishedby the software of SimDriveline, and then the model is tested. The test results show us that thedeveloped control strategy has good control effect in the process of automatic engagement control.(5) A brief design of comprehensive performance test bench for AMT has completed, the design includes loading device, actuating device and measuring equipment.