Research On A New Type Of Power Split Automatic Transmission

The research object in this paper is a new type of power split automatic transmission (PSAT) for vehicle, and its systematic study work is carried out by means of theory analysis, simulation, prototype development and experiments.The scheme of power split automatic transmission for mini-car is presented, composed of V-belt continuously variable unit and two freedom planetary gear train, magnetic powder clutch (MPC)and electronic control unit, etc.Through computer aid design, the power split automatic transmission is designed, and 3-D computer design model of power split automatic transmission is obtained. By means of analysis of kinematics, power flow, power split ratio, and transmission efficiency, the relationship of main design parameters with speed ratio, power split ratio and transmission efficiency is derived.Two schemes of mechanical adjusting and electromotor control are presented for the power split automatic transmission's key part, continuously variable unit (CVU). By means of mechanics modeling and simulation, the quantitative relationship between the design parameters and the performance of PSAT is obtained. The research on speed ratio control based on sliding model variable structure controller of angular displacement is done.The study of the magnetic powder clutch application, including dynamic experiments and control research are carried out. Through experiments, the rules of the magnetic powder clutch are explored and some values of control parameters are obtained. Fuzzy technology is applied, and control strategy and parameters' definition are described in detail.The shifting schedule of the power split automatic transmission definition is described. Neural network technology is applied to intelligent shifting research. In order to define optimum control algorithm, the integrated shifting dynamic models of engine, magnetic powder clutch and transmission set are established. The shifting process is simulated and analyzed thoroughly.Modeling and simulation are done for the vehicle performance equipped with the power split automatic transmission.The first power split automatic transmission prototype is developed, and its performance experiments are carried out. Prototype development and performance experiments verify the right of design, calculation and research work, and the result is satisfied.