The Performance Evaluation Of CAN-bus System In Hybrid Electric Vehicle And The Design Of ABS Node

Hybrid Electric Vehicles(HEV),employing different energy convertdevises,have incomparable advangtages of traditional internal combustion vehicles in fuel economy and emission. The Controller Area Network(CAN) is a serial communications protocol which is empoldered by the company of BOSCH to solve the data communication among lots of control units and test equipments.The series of SAE Recommended Practices has been developed by the Truck & Bus Control and Communications Network Subcommittee of The Truck & Electronics Committee.It efficiently supports distributed realtime control with a high-speed network and mainly used in Bus,The Truck,agricultural and construction vehicles.The thesis is based on the Hybrid Electric Bus with double high-speed CAN network lingking the various electronic control units in the bus.There are 3 nodes such as engine control unit(ECU),AMT control unit(ACU) and hybrid-energy control unit (HCU) in CAN_A network and the CAN_B network is made by motor control unit(MCU),battery control unit(BCU) and HCU.The node of HCU is bothin the two networks,so it also plays a gateway role.That is to say,between the network of CAN_A and CAN_B,the data or the messages can be commuted by the node of HCU.In order to make sure the integrality and validity of CAN-bus used by Hybrid Electric Bus,we made tests using the software as CANoe,CANScope,CANStress which are produced by the company of VECTOR.The purpose of tests are as follows:1,The robustness of communication network;2,The robustness of the electrical;Compared with the traditional braking system,the system in the Hybrid Electric Bus add the regenerative braking function.In the process of the ABS working,HCU give it the biggest motor brake torque,actual braking torque and the SOC of battery. When the ABS(Anti-lock Brake System) startup,it need the parameters from other nodes,so the control unit of ABS should be added in the CAN-bus network,which can reduce the number of sensors and depress the cost of the whole bus.Before the ABS node connected to CAN-bus,the network communication protocol should be made basing on the control strategies of ABS.The protocol includes physical layer,data link layer and application layer.In the thesis,the process of constituting the protocol of applixcation layer is described detailedly.An emulation model based on the software of CANoe proved that the CAN network protocol of the ABS node is in reason and applicable.The hardwares of ABS node are MC9S12DP256 , PCA82C250 and6N137,which can connect the node to the bus.In addition,the MSCAN should be designed.The software design includes initialization,transmission and reception.