探討訊框錯誤對FlexRay通訊系統的影響

Study the Effect of Frame Errors on FlexRay Communication Systems

張哲豪(Che-Hao Chang)

指導教授 ： 陳永源

國立臺北大學/電機資訊學院/電機工程研究所/碩士(2012年)

摘要

隨著深次微米時代的到來，大量被應用在汽車上的嵌入式系統更容易因為惡劣的行車環境影響到系統的安全性，因此車用電子也比其他系統需要更高的可靠度，也因為這樣的訴求，這些系統必須加入容錯的技術來達到高可靠度的要求。然而在加入容錯技術之前，必須有一套有效的分析驗證平台驗證其系統的強韌度，才能決定哪裡需要加入容錯的技術。
　　錯誤注入在可靠度驗證上扮演了相當重要的腳色。本研究依據EN50159所規範的錯誤類型，利用錯誤情境產生器產生錯誤情境測試檔案，透過 TTX Disturbance Node將所設定的錯誤情境執行於通訊匯流排上正在傳輸的訊框(Frame)，加速系統的失敗。並以個案研究的方式在 FlexRay 節點上開發簡易的線控轉向應用系統，搭配錯誤注入平台，探討通訊匯流排上的訊框發生錯誤，對系統時脈同步的影響。實驗中將針對不同Action Point Offset與Static slot參數的設定，以及不同同步節點個數的設置來測試系統在不同的錯誤情況下，對於時脈同步容錯的有效性與優劣性，且記錄各狀態發生之時間與機率，並分析系統Missing_term之失敗行為。

關鍵字

線控駕駛 ； EN50159 ； FlexRay ； TTX Disturbance Node ； Action Point Offset ； Static slot ； 時脈同步

並列摘要

With the advent of very deep sub-micron technology, the embedded systems used in the automotive are becoming more susceptible to a harsher external environment. With that, there is an ultimate need that the automotive electronic systems must possess higher reliability as compared with the other systems. Fault-tolerant technology must be integrated in order to achieve such requirement. Prior to that, the designer must have an effective method in verifying the system’s safety/robustness and in identifying the critical parts that need to be protected.
　　Fault injection is often employed in validating the system’s reliability and safety. In this study, we propose a fault injection platform for FlexRay communication systems and use TTX Disturbance Node which injects faults in compliance with EN50159 standards into the communication bus to interfere with the transmission frames. We demonstrate the proposed fault injection platform by a simplified FlexRay steer-by-wire system to show the feasibility of the fault injection platform. The injection platform is utilized to explore the clock synchronization problem when the frames incur faults. In the experiments, we explore the effect of varying the action point offset (APO), length of static slot, and the number of Sync Nodes on the clock synchronization process due to the occurrence of delayed frame errors and deleted frame errors. In addition, status occurrence timing and the failure rate are recorded. Lastly, analysis of the fault behavior is performed.

並列關鍵字

Steer-by-wire ； EN50159 ； FlexRay ； TTX Disturbance Node ； Action Point Offset ； Static slot ； Clock Synchronization

參考文獻

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