Dynamic Modeling and Analysis of the Hydraulic System of Automotive Automatic Transmissions

This paper presents a dynamic model of the power circuits of the hydraulic system of automotive automatic transmissions. The model includes a variable-displacement vane-pump, a regulator as a load. The load may be any combination of leakage, compliance, and time-dependent hydraulic resistance. This model was used to analyze the dynamics of the hydraulic system of a conventional step-transmission under both fixed-ratio and shift conditions.