具學習功能之自行車自動變速系統

Abstract

自行車騎乘者在騎乘過程中，會依據自己的需求來變換檔位，以得到符合自己期望之最佳踏速範圍，例如有些騎乘者希望得到最高效率，而有些騎乘者則希望保持舒適地騎乘，符合不同需求之最佳踏速範圍會有差異。然而，由於大部分騎乘者並非受過訓練，藉由手動換檔持續維持踏速在最佳的範圍內是不容易的，且無法充分發揮變速系統的效用，在騎乘過程中也可能因為選擇了不適當的檔位而有受傷之虞。若有一套自動變速系統則可以解決上述問題。

目前自行車自動變速系統大多數並不具有學習使用者騎乘狀態的能力，而是使用出廠預設值來做為換檔條件，無法適用於所有使用者。本研究提出一具有學習功能之自動變速系統，依據使用者之騎乘習慣得到換檔時機並建立換檔策略，可以滿足不同使用者的需求。換檔策略與變速控制系統的結合是利用了微控制器，控制步進馬達轉動，配合導螺桿拉動變速器鋼線，而實現自動變速控制。

During cycling, cyclists may shift gears to obtain different gear-ratio and cadence in order to satisfy their requirements such as for the highest power output or the best comfort. However, it is not easy for those inexperienced riders to obtain the optimal cadence because they can not judge the moment to shift gears. They can not make use of the derailleur system in the correct way as well. As a result, they may feel uncomfortable, and even get hurt. Therefore, we need an automatic shift control device to avoid such situation.

There are bicycles with automatic shift control device available, but most of them are not suitable for all the cyclists due to the lack of learning ability. This paper presents an automatic shift control device with learning ability. The MCU records the pedaling cadence during cycling, and then develops the strategy about the correct up-shifting or down-shifting moment. The MCU also commands the actuators to shift up or shift down a gear according to the strategy. Finally, the automatic shift control device can help cyclists to pedal at the optimal cadence.