Application of Reduced Order Model to Automotive Engine Control System

This study deals with a multivariable automotive engine control system using a reduced order model. The system controls the engine torque and air fuel rate (A/F) simultaneously using linear quadratic (LQ) control theory. The mathematical model is obtained using a statistical identification method. The instrumental variable method is employed to estimate the parameters of the mathematical model. This model is reduced to an eighth-order one using minimal realization. A 16-bit microprocessor is employed for actual construction of the control system, and a step response test was conducted. As a result, the system yielded a response similar to the simulation results.