Study On Canopen And Its Application In Hybrid Electric Vehicle Network

Today, as oil consumption and environmental pollution by fuel vehicles has become increasingly serious. And hybrid electric vehicles (Hybrid Electric Vehicles, HEV), which combine advantages of internal combustion engines and electric vehicles, is one of the most practical significance ways to solve the problem of sewage and energy. Furthermore, the trend to replace the mechanical parts in vehicle by microcontrollers makes the networklized systematic controlling an important research field in current vehicle research domain. As one of the main network platforms, CAN (Controller Area Network) bus, because of its low cost, high reliability, high anti-interference ability and high real-time characteristics, has been the main carrier within a vehicle control network. Among the existed high level protocols based on CAN, the CANopen application layer protocol possesses excellent flexibility and configuration capability. Thus it is the first choice of nowadays control networks in electric vehicles and hybrid vehicles. So the goal of our research is to design and implement the profile on HEV's CANopen.This paper first outlines the vehicles network's development background, introduces the CAN and CANopen higher layer protocols. After a detailed study for the driving system structure based on Series Hybrid Electric Vehicle (SHEV), a basic HEV's CANopen Protocol framework is built.Secondly, a CANopen protocol stack on SHEV powertrain controller node, which based on the PowerPC processor and embedded configurable operating system (eCos),is designed and implemented. And the idea, orientation with the index and determining the object with a subindex, is used for the object dictionary's construction. This method can raise the search efficiency and speed up to the object dictionary read-write speed.Then, dynamic scheduling algorithm - the first time priority scheduling algorithm (Earliest Deadline First, EDF) is introduced in the CANopen protocol network, and the effective integration of CANopen protocol and EDF advanced scheduling algorithms is achieved. Experimental results show that this method improves the network bandwidth utilization and real-time information throughout the network, reducing network load.Finally, CANopen networks system development and testings, which are based on CANoe environment, are studied. And then consistency and real-time of the CANopen slave station established above are tested. Test results show that the CANopen slave stack designed in this paper basically meet the CANopen application layer protocol standard (CiA DS301). And it can work at a maximal 2kHz data updating rate, which can meet the requirements for real-time in hybrid electric vehicles network.