CAN控制域網路節點規劃整合開發系統

Abstract

在過去的幾個十年當中，車用通訊網路在電動車輛的發展裡扮演著越來越重要的角色，然而隨著系統的複雜度增加，使得系統的表現更難以被預測及保證，本論文在以CAN控制域網路為基礎，針對其網路流量監測的方法以及網路節點規劃的流程提出可行且合理的解決辦法；CAN是一個穩定性高並具有高度安全性的串列通訊網路，能有效支援分散式即時控制系統；常見的即時網路訊息行程規劃的方式有時間觸發排程以及優先權觸發排程方式，時間排程的優點是網路的表現是可以預測且決定性的，所以經常被用於安全要求度相當高的應用裡，但缺點是每當有新的節點加入時，就必須重新規劃調整網路的行程，既耗時又耗力，所以時間觸發排程的彈性調整能力較差；相較之下，使用優先權觸發排程可以隨時新增或移除網路節點，因此有較佳的網路彈性調整能力，但不易準確地預測網路的表現而可能導致網路訊息之間互相干擾；本論文中將在既有的學術基礎上，提出網路流量監測的方法，並發展出一套符合實際運用的CAN網路節點整合開發系統，最後以電動代步車為對象設計出新的CAN網路節點。

In the last decades, the in-vehicle communication plays a more and more important role in the development of automotive technology. With the growing of complexity of these systems, the timing performance became harder to be guaranteed and predicted. In this thesis, focuses will be taken on feasible method for monitoring bus utilization and procedure of network node planning based on Controller Area Network (CAN) communication system. CAN is a well-designed communication system with high reliability and security, and effectively support distributed real-time control systems. The common real-time schedulers are time-driven scheduling and priority-driven scheduling. Time-driven scheduling is predictable and deterministic but inflexible and time consuming; on the other hand, priority-driven scheduling is more flexible but unpredictable. As the increasing number of CAN node messages, the schedulability of CAN messages became harder to predict. The method of calculating bus utilization will be presented using on-board CAN node. A new CAN communication node will be designed to meet the requirement of electric vehicles. At the end, an integrated CAN node planning system was created to help network designers to plan new CAN nodes properly.