Automated manual transmission with a torque gap filler Part 2: control and experimental validation

This paper deals with the control logic of a Torque Gap Filler AutomatedManual Transmission (TGF-AMT) and the experimental validation of the transmission dynamic model and of its control. The equations of motion of the transmission system, derived in the first part of this two-part study [1] and there used to demonstrate the effect of the TGF on the vehicle longitudinal dynamics, are here rearranged and utilised to develop the control algorithm for the transmission actuators. The controller design is carried out separating the gearshift phase into seven different sub-phases characterising the TGF-AMT operations. For each phase, the targets are discussed; moreover the equations used to compute engine, clutch and brake torque reference values are derived. Finally, the trigger conditions, determining the passage from one phase to the other, are also reported. The rigid body hypothesis, initially adopted for the transmission components, are here abandoned aiming at simulating the first torsional mode of the transmission. Therefore, a more detailed model has been implemented and it is used to test in simulation the performance of the developed controller. Finally, the authors present experimental data from two vehicles, one mounting the TGF module, the other equipped with a traditional transmission, used to compare the dynamic performance of the power shift module; moreover data are used for the experimental validation of both the transmission model and the control strategy.