Model Design for a Hydraulic Clutch Actuation System

摘要

This paper derives an accurate dynamical model of an indirectly controlled hydraulic actuation path for a wet friction clutch. The considered setup exhibits a relatively low pressure range, which necessitates to account for the variable compressibility of the hydraulic fluid due to entrained air. In addition, the model design accounts for the complex valve geometry as well as the draft angles of the valve housing due to injection moulding. The relevant hysteresis phenomena of the valves are modelled via Prandtl-Ishlinskii and LuGre operators, respectively. Simulation results show the accuracy of the model with an average error of 0.9% (180 mbar) compared to measurements. In addition, the necessity to respect the entrained air is verified by a counter-simulation with constant bulk modulus.