應用於自駕巴士之線控煞車設計與HiL測試驗證

本研究目標為發展一套線控煞車系統(brake-by-wire system)，應用於自主駕駛中小型電動巴士。本研究參考電子液壓式線控煞車設計，利用電子訊號控制前後車軸各一組的煞車致動器，並使整車的制動能力能滿足FMVSS 105與RREG的煞車法規。此外本研究結合車重估算以及前後適應性煞車力分配方法，可以依巴士在不同載客情況下，適當地分配前後輪的煞車力。減少煞車鎖死的機率，提升整車的制動能力。配合線控煞車系統的回授控制，能精確地產生目標減速度的煞車力，提升自動駕駛路徑行駛控制的準確性。本研究由Matlab/Simulink建立線控煞車控制方法，搭配dSPACE ASM整車模型進行模型在環驗證(MiL)，確保控制方法可行性與模型正確性。接著將控制方法燒錄於整車控制器dSPACE MicroAutoBox II，配合實際組裝後的線控煞車系統完成離線測試以及硬體在環驗證(HiL)。由測試結果展現本線控煞車系統能在0.5秒內快速產生及釋放煞車力，並能精準控制煞車油壓力道於2%誤差以內。在不同載客情況下，能精準計算前後輪煞車力道，減少自主駕駛策略控制煞車時的誤差，提升自駕巴士的安全性與操控性能。

關鍵字

自駕巴士；線控煞車；煞車力計算；煞車力分配； HiL驗證

並列摘要

The purpose of this research is developing a brake-by-wire system for autonomous buses. This research refers to the design of electrical hydraulic braking system, controlling brake actuators by electrical signals communication. Let the braking ability satisfy FMVSS105 and RREG regulations. This brake-by-wire system combines bus weight estimation and adaptive braking forces distribution. Under any passengers carried conditions, the brake-by-wire system can adaptively adjusts proportion of front and rear braking forces. Which can reduce wheels locked probability and increase buses deceleration. By the system close-loop controller, it can generate the target deceleration braking forces, which can increase the accuracy of autonomous strategy. The control method is established by Matlab/Simulink, combining the dSPACE ASM vehicle model to execute the Model-in-the-Loop. Through the experiment, we verify the accuracy and dynamic characteristic of the vehicle model. After finish MiL, we compile the control strategy with the vehicle controller MicroAutoBox II to conduct the off-line test and Hardware-in-the-Loop simulation. The test result shows that the brake-by-wire system can generate and release braking forces in 0.5 seconds, controlling the braking forces in 2% errors. Which can calculate front and rear braking forces exactly under any passengers carried conditions, reducing the error of autonomous strategy path control and increasing the safety and the maneuverability of autonomous buses.