Mathematical modelling of gear upshift and downshift schedule for two-wheeler amt transmission

Abstract

Gear shifting strategy is the key for the successful working of an automated manual transmission (AMT) as it affects the driving experience, fuel economy and dynamic performance of the vehicle. Depending upon the driver’s requirement, AMT can be designed for maximum acceleration performance and fuel efficiency. This project involves generation of gear shift schedule for both the maximum acceleration and fuel economy performance. To generate the gear shift schedule, a mathematical model is developed in MATLAB environment which takes input parameters as: vehicle speed, acceleration and throttle position. For generation of gear upshift schedule for maximum acceleration and fuel economy equation relating acceleration with tractive forces and vehicle’s fuel consumption equation at different throttle position is used respectively. Fuel consumption equation relates to brake specific fuel consumption (BSFC) along with vehicle structure. In order to obtain BSFC data, a GT-SUITE model of motorcycle is developed which incorporates data like gear ratio, power, torque and motorcycle weight. Finally, a buffer zone is applied to generated upshift schedule for both maximum acceleration and fuel economy case to get the downshift schedule. The generated gear shift schedule can be utilized for the development of the retrofit AMT kit on manual transmission motorcycle.