Ajitsinh A. Yadav, Tata Motors
The control strategy for an automated manual transmission is tested using a gearbox model running on a hardware-in-loop (HIL) system. The gearbox is a part of a parallel hybrid (P2) powertrain configuration. The gearbox plant model uses components from Simscape™ and Simscape Driveline™ libraries of Simulink®. The plant model can simulate gearshift forces, including synchronization forces; shift and select detent forces; shift fork leverages, and rotational and translational inertias; and shift sleeve free fly, dog clutch engagement. Gearshift is performed using two electromechanical actuators, one for shifting and other for selecting rail. Detailed models of actuators are also created using data provided by the supplier. Actuator models are validated against their technical specifications like full-load speed, no-load speed, and current drawn at various loads. The control software for AMT is designed in Simulink and Stateflow® using Model-Based Design. The control software is flashed on a rapid prototyping ECU. The plant model consisting of the gearbox and the gearshift actuators runs on HIL.