Research On The Simulation And Test Of Vehicle CVT Intelligent Control

Automatic transmission can reduce driver's intense feeling and improve passenger's comfortable feeling during a driving. It is one of the aims in the development of vehicle's power train. A continuously variable transmission (CVT) is able to achieve more efficient operating levels with respect to drive performance and fuel consumption than conventional automatic transmission.The development of automatic transmission technology is analyzed in this paper. A metal-belt CVT is chose to be an object of study. The development of CVT and its core technologies is introduced, and the control system is one of the CVT core technologies. Control arithmetic is a key of control system. Intelligent control is a new type of control techniques, and it is an advanced control theory to solve complex control issues. Intelligent control is brought into control system of metal-belt CVT to seek a better effect of controlling.The configuration, elements and control ways of metal-belt CVT with dual-pressure circuit are analyzed. The ratio and line pressure control of metal-belt CVT are emphasized in the study. A simulation model of vehicle transmission system with CVT is built by Matlab/Simulink. Fuzzy logic control (FLC) strategy of ratio controller and line pressure controller are designed and optimized. Simulation of FLC compared with normal PID controller shows that optimized FLC strategies of ratio controller and line pressure controller have better effect on control of metal belt CVT.The development of fuzzy logic microcomputer is introduced. The hardware and software of metal-belt CVT ECU is designed based on MC9S12DP256. The test rig of CVT driveline which based on frequency conversion technology and the control system of test rig that based on LabVIEW are designed in the last, paving the way for further research.