The Research Of Control Strategy On Starting Clutch For V-belt Metal CVT

The metal V-belt CVT is a type of ideal transmission for passenger cars, whichpossesses many advantages such as simple in structure, easy to operate, low cost,high efficiency, low air pollution, and so on. There will be a great developingpotentiality and extensive market in China. Because this is a new type oftransmission that integrates mechanics, hydraulics, electronics and computercontrol technology, and it is just beginning to research and develop CVT productsin China. For developing CVT products, we are facing many challenges in bothtransmission theory and its system design. Knowing and understanding thesetheories and key technologies is so important to advance our auto-industry leveland to shorten the distance in auto-industry with the developed countries that isalso the main aim for all great auto-companies. For this purpose, all aim of thedissertation is to focus on some of the key problems to develop CVT products,such as the start clutch and its control strategy, CVT electro-hydraulic controltechnology. The main work has been completed as follows: 1) After reading many reference literatures, we analyzed the features andmechanism of the metal pushing V-belt CVT. The formula of ratio changing rateeffecting on the vehicle performance is established in theory, and all factors toratio changing rate are analyzed. All achievements provide theory foundation fordeveloping CVT hydraulic system with further good characteristics. 2) Considering the development of computer technology and sensor technology,the features of multiplate wet clutch and its complicated diversity at car startingwork, the fuzzy self-adaptive PID control strategy for clutch based on the optimaltheory is adhibited. By establishing and analysing the mathematic model ofmultiplate wet clutch at starting, this strategy compromised the impulsive degreeand dissipated energy during the process at starting can achieve the goal that carcan start up steadily and rapidly. 3) Simulate the process of multiplate wet clutch working, the simulation results72show that the fuzzy self-adaptive PID controller has the better adaptive capabilityand robust capability, comparing with the regular fuzzy controller and PIDcontroller. 4) Carry out the test-bed experimentation and the whole car roadexperimentation to validate the control system for CVT starting cluth. Theexperimentation results show that the control system works in diversified workingconditions,which is useableness .It will provide a good foundation to furtherdevelopment for CVT and its electro-hydraulic system.