Hybrid control of force transients for multi-point injection engines

We address the problem of delivering as quickly as possible a requested torque produced by a spark ignition engine equipped with a multi-point port injection manifold and with electronic throttle. The optimal control problem, subject to the constraint that the air-fuel ratio stays within a pre-assigned range around the stoichiometric ratio, is solved for a detailed, cycle-accurate hybrid model with a hybrid control approach based on a two-step process. In the first step, a continuous approximation of the hybrid problem is solved exactly. Then, the control law so obtained is adjusted to satisfy the constraints imposed by the hybrid model. The quality of the control law has been in part analytically demonstrated and in part validated with simulations. Copyright (C) 2001 John Wiley & Sons, Ltd.