| Automobile is one of the symbols of human civilization, it's development must conform to the requirements of the society. The two main themes of the contemporary world are economizing energy and protecting environment. However, millions of autos running in the street are the major subjects of energy consumption and environmental pollution. Therefore, one of the directions of future automobile development is to take effective measures and apply new technology to reduce the fuel consumption and minimize exhaust gas. Because the characteristic of Internal-combustion Engine is different from that of the Ideal engine, So a transmission is needed to improve the performance of powertrain. And the most effectual and promising way is CVT ( Continuously Variable transmission ). The metal pushing V-belt type continuously variable transmission (CVT) has the advantages of simple and compact structure, easy operation, excellent performance, low cost and fuel economy. As an advanced technology to develop passenger car, it can meet the demands of developing transmission in our country. So this technology attracts much more attention in recent years. The State Commission of Science & Technology has listed this technology as one of the key projects during he Ninth-Five Plan. The transmission mechanism of the metal V-belt CVT is the theoretic basement of control system. And the control system is the key technology of the CVT. The dissertation mainly focused on the intelligent control system of the metal pushing V-Belt type CVT system. The content is as follow:In the beginning the dissertation reviews the development process and the technique of CVT briefly. Through the comparison with other transmission, it showed that the metal pushing V-Belt type CVT can meet the currently demand of drivability, economics and emission etc, and stated that the CVT is the ideal transmission, will be the developing tendency for the transmission of passenger car. In the paper the background and the necessity of this theme in science and practice are given.Because of its special structure, the transmission mechanism of metal pushing V-Belt type CVT is much different from that of the traditional rubber V-Belt. Because the transmission mechanism of CVT is the foundation of its control system, the dynamic model of metal pushing V-Belt for realtime control is established. Start from the kinematics of the belt, the load distribution and variation of the element compressive force and ring tensile force, and the relationship of the transmitted torque, ratio and clamping force, were discussed thoroughly on the basis of the hypothesized model in order to establish the dynamic model that could be used in reality. And this is the theoretical basis of CVT control.For a given driving condition, when the vehicle speed and load is constant, the ratio of the powertrain with CVT can be changed continuously, so the engine can be controlled to working in the fuel economic area. The CVT powertain model including hydraulic system is presented. The integrated control system of engine throttle and CVT ratio control is established, and some typical condition is discussed by simulation on the above mentioned model. The simulation results show the model work well, and consistent to the reality. The combination control system of engine and transmission is very important to design the control system of engine and transmission, to appraise the matching characteristic of powertrain. Considering the non-linear characteristic, coupling and parameter uncertainty, a integrated danamic model of powertrain with CVT was established. The synthesized control law of this powertrain was studied, and the matching law and control strategy of the powertrain was appraised in this paper.The powertrain with CVT is a complicated non-linear system, the input and output parameter was coupled together. At the effect of complex working condition and uncertainty of environment of vehicle, the application of traditional control method, for example PID control, was not very useful. Fuz...
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