FlexRay veriyolu statik ve dinamik bölütleri için mesaj çizelgelemesi : algoritmalar ve uygulamalar.


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Türkiye

Tezin Onay Tarihi: 2015

Tezin Dili: İngilizce

Öğrenci: Özgür Kızılay

Eş Danışman: ŞENAN ECE SCHMİDT, KLAUS VERNER SCHMİDT

Özet:

Today’s automobiles comprise an increasing number of electronic components. Some of these components are used for entertainment purposes and some of them are used for safety-critical application such as X-by-Wire that are implemented on electronic control units (ECUs). The safe data exchange among such ECUs has to be realized by a robust and reliable in-vehicle network protocol. In this context, FlexRay is one of the new generation in-vehicle network protocols which is already used in upper class series vehicles. In principle, FlexRay enables the reliable transmission of periodic and sporadic messages that are generated by ECUs on two communication channels. Nonetheless, it is the user’s responsibility to configure the FlexRay parameters. In particular, it is required to determine a message schedule such that each message meets its deadline. In general, two types of messages – periodic and sporadic messages – are considered. In FlexRay, periodic messages are transmitted in the static segment and sporadic messages are transmitted in the dynamic segment. Since these two types of messages have v different timing characteristics and the corresponding segments in FlexRay have different arbitration properties, their scheduling has to be performed by different types of algorithms. In this thesis, we focus on the message scheduling on the static segment and the dynamic segment of FlexRay. We first analyze practical requirements for the static segment scheduling based on previous studies that involve the solution of a linear integer problem (LIP). In order to circumvent the requirement for an LIP solver, a new heuristic static segment scheduling algorithm is developed and implemented. Its performance is evaluated by several test cases. Next, we consider the FlexRay dynamic segment. We first propose an improvement of an existing algorithm for the worst-case response time analysis and then develop a new algorithm for the priority assignment on the FlexRay dynamic segment. The practicability of the presented algorithms is established by various examples.