A Study on Electronically Controlled Continuously Variable Transmission for Motor Scooters

摘要

The Continuously Variable Transmission (CVT) in traditional motor scooters uses centrifugal rollers to automatically change ratio and hence output speed in response to varying driving conditions. When these changes occur, the engine operating conditions often change, impacting the power transmission and increasing fuel consumption. This study focuses on the maneuverability and safety of CVT equipped motor scooters by attempting to select more ideal operating conditions for the engine by actively adjusting the gear ratio resulting in higher engine speeds without affecting cruising speeds. The use of active control can prevent accidents caused by wheel locking because engine braking could be engaged during an emergency stop. This would lower the amount of force required to brake. This study aims to achieve these goals using a system which can be easily applied to a production vehicle, reducing development costs. During this study, experiments on Electronically controlled continuously variable transmission (E-CVT) produced the following conclusions: (1) An experimental E-CVT platform was constructed and active control of gear ratio was achieved using a user interface which sends control commands based on various measurements. (2) A graph of output speeds against input speed at various gear ratios was constructed as a result of this study. Using this data, precise control of the changes in gear ratio could be achieved.