On the use of Engine Modulation for Deceleration Control of Continuously Variable Transmission Vehicles

The design and evaluation of a control system for a continuously variable transmission (CVT) vehicle is presented in this paper. Studied and simulated are the following three topics: design and evaluation of the control system with a CVT vehicle in acceleration, deceleration and to the sensitivity of the system with respect to changing characteristics of the engine (hot, cold, age). It is shown that the control system proposed here could insure good stability and controllability not only for acceleration of the system but also for deceleration operation, provided that a pulse width modulated (PWM) fuel control scheme for the engine is employed in the system. It seems that the control system designed in this paper is not complicated and does not have large sensitivity with respect to variation of the characteristics of the components of the system and provides the best possible fuel efficiency. In addition, a number of alternate decelerating schemes are presented at the end of the paper for comparison.