Switched Causal Modeling of Transmission With Clutch in Hybrid Electric Vehicles

Certain difficulties arise when attempting to model a clutch in a power train transmission due to its nonlinear behavior. Two different states have to be taken into account—the first being when the clutch is locked and the second being when the clutch is slipping. In this paper, a clutch model is developed using the Energetic Macroscopic Representation, which is, in turn, used in the modeling of complete hybrid electric vehicles (HEVs). Two different models are used, and a specific condition defining the commutation between both models with respect to the physical energy flow is proposed. A Petri net is employed to activate one of the models, depending on the clutch state (locked or slipping). This model allows us to implement without difficulty a simulation of the clutch with a relatively short computation time.