Design And Research Of The Electronic Control Unit For The Metal Belt Continuously Variable Transmission

The Metal Belt Continuously Variable Transmission (CVT) is a kind of ideal transmission. Compared with routine hydraulic-mechanic transmission , it has many merits, such as excellent performance, compact structure, convenient handling and low price and so on. Therefore, it has been used widely. In our country, as one of the key projects, it has been developed and researched. So the electronic control metal belt CVT , which has lower oil consumption and superb dynamic performance ,is the focus in this research field. This paper introduces the mechanical structure, characteristic, work principle and the control principle of the electronic metal belt CVT. On mechanics it mainly consists of the drive pulley, the driven pulley, the push belt, the oil pump, the final reduction, the differential gear, electronic parts and so on. Different to the common belt, the metal V-belt transmits the power through the pushing force between the segments. The Electronic Control Unit (ECU) is the core of control system of CVT. According to the information from the various sensors ,the ECU estimates the states of vehicle, the conditions of the road and the purpose of the driver, decides and controls the operation of the clutches, the torque convertor lock-up and controls the continuously change of the speed ratio within a certain range ,improves the fuel economy and driveability. In this paper the engine model including the torque model,the oil consumption model and the rotate speed adjusting model is established through the way of cubic polynomical approximating based on the experimental datas. In the paper the simplified model of the CVT power train is also established, and the matching between the engine and the CVT and the control strategy of CVT are studied. It requires the CVT enables exact matching of the fuel-optimal engine operating points to the vehicle speed and realizing a high fuel economy and driveability. The ratio control policies in different work conditions are analyzed. It is essential to develop Electronic Control Unit (ECU) for electronic and...