機車電子控制式連動煞車系統之研究

我國法規規定，2021年起，125cc以下新出廠機車可選擇加裝防鎖死煞車系統(Anti-lock Braking System, ABS)或連動式煞車系統(Combined Brake System, CBS)，為確保機車駕駛者及乘客的行車安全性。CBS是一種連動前、後輪煞車的機構，駕駛者只需要按壓左手煞車拉桿，前後輪均會產生煞車力。目前市面上的CBS設計大都採用前後輪煞車力固定比例的設計。因為必須保證後輪比前輪先煞車，固定比例CBS的前後輪煞車力比例設計結果通常為前輪40%後輪60%，此一比例容易導致後輪鎖死量過大而甩尾，在舒適性與安全性上並不理想。最佳的CBS設計須考慮煞車時的負載轉移效應，方能使前後輪煞車力比例為最佳，但因承載一人或兩人時，最佳前後輪分配曲線差異大，難以設計出最佳曲線同時符合不同負載條件，本研究主要探討一種電控CBS設計(Electronic controlled Combined Brake System, ECBS)之可行性，期望藉於不同負載條件下，前後輪之煞車力分配曲線均能為最佳。本研究已經完成一種電子控制式連動煞車機構設計、試作與控制器設計，並完成各項實車測試與性能評估。所提出的新設計，具備構造簡單、節省空間、成本低以及控制簡單化之優點。實車測試結果顯示，本研究之控制方法可以利用最簡單的控制方式，控制後輪煞車力提前量於50至150N之間，進而控制了分配曲線的高度，證實了本研究所提的ECBS機構與控制構想具備應用之可行性。此一結果意味著本研究所提出的控制方法，除了可以讓ECBS在不同負載條件下，控制煞車力分配曲線高於理想曲線一個安全最佳範圍內之外，也可保證在各項失效模式下，連動側之煞車性能皆符合安全需求，例如，保證後輪先煞車與先鎖死；前輪失效時，後輪保有足夠煞車力；且左右手之煞車分別或同時操作時，皆不會互相干涉。關鍵字：連動煞車系統、電子控制式連動煞車系統、輪速控制、機車煞車動態特性。

關鍵字

連動煞車系統；電子控制式連動煞車系統；輪速控制；機車煞車動態特性

並列摘要

According to the regulations in Taiwan, starting from 2021, new models of scooters with engine displacement under 125cc have to equipment with anti-lock braking system (ABS) or combined brake system (CBS). The CBS is a system that make the drivers brake both the front and rear wheels only use one of the brake handlebars. At present, most CBS designs in the market are of constant force distribution proportion between front and rear wheels, namely the simple CBS. Because it is necessary to ensure that the rear wheel brakes prior to the front wheel, the force distribution proportion of the simple CBS are usually with 40% for front wheel and 60% for rear wheel. This design is not ideal in terms of comfort and safety, because it is with high possibility of leading to drifting motion on emergency brake due to the rear wheel locked too early prior to front wheel. Ideally, the value of the force distribution proportion of a CBS should be set to be varied with amount of load transfer as well as load condition over the entire brake force range the driver apply to. However, because the load on the scooter is changed largely in practice, it is difficult to design a single force distribution proportion curve ideally for the CBS. It is with this motivation, this study proposes an idea called as electronic controlled CBS (ECBS) that can change force distribution proportion automatically to adaptive to load variation of the scooters. The idea is realized with a simple mechanism and easy to implement control method in this thesis. To investigate the feasibility of the proposed idea, a prototype was set up and applied to a scooter. The associated experiments were also conducted. All the test results showed that the proposed control method associated the CBS mechanism can control the brake force distribution proportion between front and rear wheels as expected, which proves the feasibility of the proposed ECBS mechanism and control. Moreover, test results also showed that the ECBS can guarantee safety on braking under various failure modes. For example, rear wheel braked and locked prior to front wheel. When the front wheel fails, the rear wheel remains sufficient braking force. Finally, whenever the left and right brakes levers operated separately or simultaneously, the drivers do not have the feeling of mechanical interference existing in CBS mechanism. Keywords: Scooter, Combined Brake System, Electronic Controlled Combined Brake System, Wheel speed control, Brake Dynamics.