Stability analysis of residual-affected HCCI using convex optimization

Residual-affected homogeneous charge compression ignition (HCCI) is a promising methodology for simultaneously reducing emissions and fuel consumption. However, the process relies on cycle-to-cycle coupling between subsequent engine cycles through the exhaust gas temperature, resulting in sections of the state space which are unstable. This paper exploits a previously validated control model of HCCI to analytically determine the area of the state space which is stable to perturbation of either combustion timing or in-cylinder pressure. 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.