| 摘要 |
An electronic system controlled by a micro-controller for automatically shifting gears while cycling a bicycle, the system can be attached to or removed from most modern bicycles without compromising the structural integrity of the bicycle, the cyclist can choose to use the system or to change gears manually. The system is controlled by a micro-controller. The micro-controller is programmed to calculate how fast the cyclist is pedalling using a reed switch. Based on this information the system automatically selects the correct bicycle gear. The system uses a servo motor to either apply or release tension on the gear cable which causes the rear derailleur to change the bicycle gear. The system is attached to the bicycle without the bicycle needing to be modified and without damaging the bicycle, it achieves this by using the hex bolts on the crossbar to mount the control box and servo motor. The reed switch is mounted using a custom made bracket made from sheet aluminium which is attached with cable ties and the dashboard box is mounted using a bicycle camera mount. The cyclist can have the system shift the gears automatically for them but can still shift gears manually when the system is powered off, as the servo motor moves freely when it has no power. <Figure 2> |
