Research Of Vehicle Control Network Based On CANopen Protocol

In order to improve the ride comfort, handling and safety of vehicles, more andmore electronic control unit is integrated into the control system of auto mobile.Because of the need to transmit a large number of data between the ECU with highspeed, the traditional way of point-to-point connection has been replaced withdistributed control network. The CAN communication protocol for cars has becomea standard protocol of the car network. But the CAN protocol doesn’t define theapplication layer, so the user requires to define the meaning of the data transmittedin the networks, and realize network management, which increases the complexityand cost of the development.As the CAN bus application layer protocol, CANopen protocol has gainedwide acceptance and application, but it hasn’t been applied to the vehicle, due tolacking of the standard application specification. Based on the analysis of CANopenprotocol and topological structure of vehicle control network, this paper implementsa vehicle control network based on CANopen protocol, and define the related deviceprofile, according to the specification of each device in the network. About objectdictionary, this paper gives a program implementation. And through the research ofusing hash table to realize object dictionary, this paper puts forward a way by arrayand linked list.The CANoe can be used to develop a CANopen network, which doesn’t needthe support of related hardware. Through testing the consistency and performance,we verify that the network simulation meets the requirements.Although CANopen Protocol can improve the flexibility of the networkconfiguration and the interoperability between different devices, the communicationobject is defined based on the can message. In the CANopen network, real-timemessages are transferred by PDO. When the network has a big load, low priorityPDO will be blocked, then has a longer waiting time. To solve this problem, thispaper has a research of realizing the EDF scheduling algorithm for CANopenprotocol, and verifies the feasibility through a simulation.