Shift Schedule Modification for Automated Manual Transmission Based on Road Slope Identification

Abstract

Identification of the road slope is a key issue for automated manual transmission (AMT) to have its shift schedule adapt to the slope change during operation. To tackle the problem of frequent gearshift on ramp of the traditional shift schedule, a slope recognition method based on the vehicle's acceleration is proposed and the traditional shift schedule has been modified using genetic algorithm. The shift performance of running on ramp has been analyzed and the traditional shift schedule has been modified to get rid of its weakness when traveling on the ramp. Genetic algorithm has been used to calculate the shift schedule. Simulation result show that modified shift schedule can adapt to the slope change effectively. Keywords-slope recognition; shift schedule; automated manual transmission I. INTRODUCTION With the development of electronic and control technologies, automatic transmission has been widely used in modern vehicle. It reduces the fatigue strength of drivers and the requirements on the driver's driving skills, effectively improves the power performance, fuel economy, and emission of automobile. These properties are mainly affected by the shift schedule for the vehicle equipped with AMT(automated manual transmission), which defines the time of gear shifting according to the variation of the control parameters. The traditional shift schedule is based on vehicle speed and throttle opening on good level road, which does not consider the influence of slope on gearshift performance and therefore can not adapt to the slope change of road, and may make the gearshift occur frequently and also reduce the overall performance of the vehicle. In order to improve the adaptability of automatic transmission to the slope change of driving road, it is very important for AMT ( automated manual transmission) vehicle to modify the traditional shift schedule when the vehicle travels on ramp according to change of the slope of road.