Research On The General Calibration System Of Electronic Control Unit Based On XCP

The rapid development of automobile technology has greatly increased the control parameters contained in ECU,thus the complexity of calibration is getting higher and higher.In the meantime,the performance of a vehicle is directly affected by the the calibration work of control parameters in the final stage of ECU development.Therefore,a universal calibration system with functional modules and user-friendly interface is of high application value.On the basis of a comprehensive study of the calibration system development both at home and abroad,the paper offers a summary of its basic characteristics and functional requirements,and implements one such system based on XCP calibration protocol.Its acrchiectture accords with the widley recognized ASAM MCD standard,and the key componets include the ECU slave,CANUSB-2 device and the upper calibratioin software on PC.All commonly-used communication buses like CAN,FlexRay and LIN are supported by XCP calibration protocol,and thus guarantees the versatility and extensibility of the system.With a profound study of the technical specifications like CAN and XCP,both calibratioin drivers on the ECU and a calibratioin software on the PC are designed and implemented.The calibratioin software is coded with LABVIEW,and composes of the interface module,the XCP protocol stack,CAN driver and A2 L file parser.The idea of Software Component(SW-C)is adopted to define unified data structures and interfaces for different modules.The data monitoring and parameter calibration interface module can interact with the calibration engineers using the LABVIEW user event processor structure.The XCP protocol stack module is responsible for encapsulating user instructions as CTO packets and parsing DTO packets.The CAN driver realizes the data communication between the upper computer and the ECU through CAN bus;The A2 L file parser is responsible for the parsing of the ECU description file and generates a list of parameters for the calibration engineer to use.The software package on the ECU is coded using C language,which includes hardware drivers and the XCP protocol stack.The CAN communication driver is implemented on the MCP2515 CAN controller,and the XCP protocol stack is composed of two functional modules,namely the CMD processor and the DAQ processor.The calibration system is tested and verified in chapter 6.Firstly,a simple test program is degined to verify the communication and calibration function of the ECU driver softeware package,and the A2 L file parser is tested after that.Finally,the measurement and calibration functions of the calibration software are verified by using the experiment bench of the DCT electromechanical coupling gearbox.The results show that all functional modules of the calibration system is stable and reliable,which can meet the requirements of daily measurement and calibration work.