This paper proposes an engine speed tracking controller based on the MPC scheme and investigates a tuning method for the practical control performance from the viewpoint of the ILQ design. First, the nonlinear system dynamics based on the engine mean-value model is transformed to the linear tracking error dynamics by the feedback linearization method. Then the MPC speed tracking controller is designed based on the derived tracking error dynamical model. To achieve the convenient adjustment of the control performance, the quadratic weightings in MPC performance index are calculated with respect to a single tuning parameter by means of the inverse optimality conditions of the LQ optimal problem. Moreover, an adaptive compensator is introduced to guarantee the control precision even if the predictive model is not very accurate. Experiments are conducted in the 3.5L-V6 gasoline engine test bed, the results demonstrate the good control effects for speed tracking by the proposed MPC controller and also confirm the validity of the proposed tuning approach.
2015 The Society of Instrument and Control Engineers