Coordinated control of gear shifting process with multiple clutches for power-shift transmission

In this work, a novel power-shift transmission is designed to achieve high transmission efficiency, reasonable gear distribution, and high fuel economy with relatively low processing difficulty and low manufacturing cost. Moreover, the parameters of this transmission are designed based on work requirements and the relative service time of each speed range during the life cycle of a tractor. Since gear shifts between some gears require a change in the states of four clutches, this process is very complex. In order to ensure the gear shifting quality and continuous power flow to driving wheels, the powertrain dynamical model is established, the power-on gear shifting processes are analyzed, and the coordinated control strategies are developed for upshift and downshift processes with changing multiple clutches during tractor field work. The effectiveness of the gear shifting control strategy is verified using the proposed simulation model. The results show that the coordinated control strategies ensure excellent power continuity, smoothness, and responsiveness for power-on upshift and power-on downshift processes with changing multiple clutches. (C) 2019 Elsevier Ltd. All rights reserved.