Novel Automated Manual Transmission Gear-Shift Map Modelling Based on Throttle Position

Abstract

Automated Manual Transmission (AMT) is capable of providing good driving comfort and performance with increased fuel efficiency of the automobile. In an AMT, gearshift maps are popularly used for shifting gears. In this work, a novel strategy of shifting gears in an AMT is proposed by utilizing a set of polynomial functions instead of using gear-shift maps directly for shifting the gears. These polynomial functions are precisely extracted from the master gear-shift map of an automobile. Polynomial functions are obtained in MATLAB from gear-shift maps available in literature using curve fitting technique. Mathematical model of a driveline is obtained from free body diagrams of each part. Driveline models are divided into three categories depending on different phases of operation of driveline as: engaged model, slipping model and synchronization model. State-space mathematical models are thereafter derived for each phase.
Simulations are done using these state-space models in which polynomial functions are used for gear shifting. Results demonstrate that polynomial functions for gear-shaft maps can be effectively utilized for shifting gears under different loads and throttle positions.