Concept evaluation of a novel gear selector for automated manual transmissions

Abstract The existing Automatic Mechanical Transmission (AMT), whether electrically or hydraulically actuated, integrates shift actuators with gearbox shell as one unit by installing actuators on the gearbox. The problem it brings about is that the modification of the gearbox shell would be required, which increases the cost of AMT system. This paper proposes a novel gear selector for AMT, the concept of which enables the automation of shift action remotely realized by DC motors through shifting cable that originally used on manual transmission vehicle. Evidently, the advantage of this concept is that the automation of manual transmission could be easily realized by replacing the shift lever with two motors while the original shifting cable and gearbox could be reserved. Then the cost and development period can be shorten remarkably. Firstly, the concept of the novel gear selector is introduced, then the detailed mathematical model of shifting process is studied, and system design and scheme selection of this concept are performed. Optimal control algorithm based on LQR for actuator position feedback control is introduced. The concept and control algorithm are verified on a sample car, and considering the influence of the long path of transmission mechanism, the validation of the stability of this concept is performed through calibration test on mountain pass, and the obtained results show the concept of the novel gear selector for AMT is feasible technically with strong robust on the shifting stability, and it shows enormous potential for industrialization.