Tuning of nonlinear model predictive controller for the speed control of spark ignition engines

This paper presents the speed control of mean-value model of spark ignition (SI) engines by efficiently tuning nonlinear model predictive controller (NMPC). The quadratic cost function in NMPC is tuned by applying the inverse optimality conditions on the linear quadratic regulator designed for the linearized model using the inverse linear quadratic (ILQ) regulator design method. This approach provides some tuning parameters that give a trade-off between the speed of the system´s response and the magnitude of the control input. Effectiveness of the tuning method is elaborated in simulation results.