An analytical review on automatic gear shifting in automatic transmission

This paper presents a literature overview of factors, both internal and external, modelled for improving the shift-quality in automobiles through the development of a robust electronic transmission control unit (TCU). Such robustness, designed with considerations of internal and external factors, are essential for safety and driving comfort. As automobiles are becoming more sophisticated, the application of electronics and embedded systems is increasing for different functional control system designs, including the gear-shifting mechanism. An automotive transmission system equipped with electronic or electrohydraulic actuators, controlled by an electronic control unit, provides clutch-less driving experience to the driver for the shifting operation. TCU is used for automatic speed and torque control in different driving situations, and reduces the human error in gear selection for facilitating safe and comfortable driving. In the development of such a mechatronic controller, it is critical to find a robust control strategy in the context of semi-autonomous vehicles.