A Model Predictive Controller for the Cooling System of Internal Combustion Engines

The paper presents some results of the Model Predictive Controller (MPC) methodology applied to the case of the cooling system of an Internal Combustion Engine. To this end, a small spark ignition engine, about 1.2 dm3 displacement volume, is equipped with an electric pump, which is actuated by the controller, independently of engine speed. The goal of the proposed control is to achieve a faster engine warm-up and an effective engine cooling with a much lower coolant flow rate than the one usually adopted, by bringing the cooling system to operate around the onset of nucleate boiling. The developed Model Predictive Control application makes use of a lumped-parameter model, which predicts the heat transfer both in the case of a single-phase forced convection condition and in the presence of nucleate boiling. The performance of the proposed controller is evaluated during the city driving part of the NEDC homologation cycle, which was replicated at the engine test rig. The results show that the proposed controller is robust in terms of disturbance rejection and is effective in reducing warm-up time.