Joint Air Fuel Ratio and Torque Regulation using Secondary Cylinder Air Flow Actuators

Actuation schemes exist that permit the joint manage ment of air and fuel ow into the cylinders of a spark ignition engine With the exception of drive by wire systems to date the transient control aspects of these schemes collectively refered to here as secondary cylin der air ow actuators has not received any attention from the control community This paper takes a rst step in the analysis of the simultaneous dynamic control of air fuel ratio and torque response using secondary actuators placed before the intake ports of the cylin ders when used in combination with standard fuel in jectors and primary throttle regulated by the driver The emphasis is on basic issues of designing a feedfor ward scheme to enhance actuator authority for feedback control and the fundamental multi variable nature of the feedback problem Enhanced transient air to fuel ratio performance improvement is shown to be possible without sacri cing engine torque response with respect to a conventional engine In addition this is achieved with overall higher manifold pressure o ering the pos sibility of reduced pumping losses in the engine depend ing on the actual actuation scheme employed