Two-Degree-of-Freedom Controller Design for Clutch Slip Control of Automatic Transmission

To improve shift quality of vehicle with clutch-to-clutch gear shifts, a two-degree-of-freedom controller, including a clutch pressure estimator, is designed for clutch control during the inertia phase of the shift process. The controller is designed based on a low order linear model which is derived from dynamics of the proportional pressure control valve and the vehicle drive line. Then the calculated controller is evaluated on the constructed nonlinear powertrain simulation model. Simulation results show that the rotational speed difference clutch can track the desired trajectory well, and shock can be reduced by designing suitable feedforward compensator.