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

摘要

This paper deals with the control logic of an automated manual transmission with a torque gap filler and the experimental validation of the transmission dynamic model and of its control. The equations of motion of the transmission system, derived in Part 1 of this two-part study and there used to demonstrate the effect of the torque gap filler on the vehicle's longitudinal dynamics, are here rearranged and utilized to develop the control algorithm for the transmission actuators. The controller design is carried out, separating the gearshift phase into seven different subphases characterizing the operations of an automated manual transmission with a torque gap filler. For each phase, the targets are discussed; moreover, the equations used to compute the torque reference values of the engine, the clutch and the brake are derived. Finally, the trigger conditions, which determine the change from one phase to the other, are also reported. The rigid-body hypothesis, which was initially adopted for the transmission components, is here abandoned, with the aim of simulating the first torsional mode of the transmission. Therefore, a more detailed model was implemented, and it is used to test in simulations the performance of the developed controller. Finally, experimental data are presented from two vehicles, one with the torque gap filler module, and the other equipped with a traditional transmission, used to demonstrate the vehicle's dynamic performance enhancement obtained owing to the powershift module; moreover, data are used for experimental validation of both the transmission model and the control strategy.