Optimizing gear shifting by shift pattern rescheduling and collaborative control between engine and automatic transmission

This paper discusses two practical issues in automotive powertrain control; optimization of gear shift patterns to balance driving performance and fuel economy, and smoother gear shifting to improve riding comfort. A real-time shift rescheduling method is proposed and evaluated to show its effectiveness for flexible tuning between performance and fuel economy. For smooth gear shifting, a collaborative control scheme between engine and automatic transmission (AT) gearbox is discussed to aim for a more fundamental torque control of the powertrain. To facilitate model-based approach, an AT gearbox model is devised using hybrid systems techniques to represent the discrete-event nature of automatic transmissions. © 2008 Society of Automotive Engineers of Japan, Inc. All rights reserved.