A Hybrid System Approach to Modeling and Optimal Control of DISC Engines

This paper illustrates the application of hybrid mod-eling and optimal control to the problem of air-to-fuel ratio and torque control in advanced technology gaso-line direct injection stratified charge (DISC) engines. DISC engines have two discrete modes of operation, stratified and homogeneous, and their dynamic behav-ior can be easily captured by a hybrid model. We show that the design flow (hybrid modeling and controller synthesis) is simple in terms of problem setup and tun-ing, provides good closed-loop performance, and leads to a control law that can be implemented on automo-tive hardware as a piecewise affine function of the mea-sured and estimated quantities.