Control system design for steady state operation and mode switching of an engine with cylinder deactivation

Over the past decades, government legislations have placed increasingly stringent standard on numerous aspects of automotive performance; with safety and exhaust emissions being two of the most dramatically affected. Fuel economy standards (passenger car CAFE), however, have not increased since 1986. Present standards are likely to increase; either based on carbon dioxide global warming concerns, pressures to reduce crude oil consumption. Competitive industry trends may force fuel economy improvement at an even quicker pace. In the present paper cylinder deactivation improvement of engine efficiency is examined. The nature of cylinder deactivation technology and stringent operational requirements leads to significant updates and additions to conventional IC engine controller strategy. Areas significantly affected are, engine mode selection, engine mode transition, torque to air-change (electronic throttle control etc.), and variable cam timing (VCT) scheduling. Improvements to these areas focus not only on controller performance, but also on calibration efficiency.