Robust Nonlinear Control of an Innovative Engine Cooling System

In this paper, a robust nonlinear control of an engine cooling system for vehicles is presented, where an electrically driven radiator fan serves as the control input. A simplified control-oriented model of the engine cooling system is derived using the first law of thermodynamics. The control design is based on an integral sliding mode approach and aims at tracking of desired trajectories for the engine outlet temperature. A gain-scheduled modified Utkin sliding mode observer, which uses both a switching term and an output error feedback, is employed to estimate unknown heat ows acting as system disturbances. The estimated heat ows are used in the control structure for a disturbance compensation. An experimental analysis highlights the effectiveness of the integral sliding mode control strategy in combination with the gain-scheduled sliding mode observer.