STABILITY ANALYSIS OF RESIDUAL-AFFECTED HCCI USING CONVEX OPTIMIZATION

Homogeneous Charge Compression Ignition (HCCI) is a promising methodology for simultaneously reducing emissions and fuel consumption in internal combustion engines. One approach to achieving HCCI is via reinduction or trapping of hot combustion gas, which results in cycle-to-cycle coupling between subsequent engine cycles through the exhaust gas temperature. A consequence of this coupling are sections of the state space which exhibit either stable or unstable responses to perturbations. This paper exploits the characteristics of a previously validated 2-input 2-output control model of residual-affected HCCI to analytically determine the area of the state space which is stable to perturbation of either combustion timing or in-cylinder pressure evolution. As efforts to control and expand the operating range of HCCI continue, analytical stability tools like that developed here will likely play an increasingly important role.