Research On The General Calibration System Of Electronical Control Unit Based On CCP

Matching and calibration test is the final stage of development forvehicle-mounted ECU (Electronic Control Unit), tedious calibration tests areneeded. With the increased complexity of the electronic control systemfunctions as well as more control parameters, fully functional andconvenient calibration system is necessary.After the survey of some widely used calibration system in the market,this paper develops a general-used ECU calibration system based on CCP.The system is mainly composed by an ECU, calibration software in the PCand a connecting CANUSB interface card. In order to guarantee thegenerality of the system, CCP as an internationally accepted communicationprotocol is implemented strictly on both sides of the calibration system. Tomake the calibration software in the PC unrelated to specific ECU, ASAP2standardized parameter description file (.a2l file) is used for thecommunication between the ECU and the calibration software.Based on the in-depth study of CCP protocol and demand analysis forcalibration system, CCP driver in the ECU and calibration software on the PCare designed and developed. CCP driver works for the interpretation ofcalibration protocol message and is developed in CodeWarrior IDE. Calibration software in the PC is developed by using LabVIEW. Software isdesigned to fulfill the functional requirement and modular programming isadopted to develop the software functions such as data acquisition,calibration, ASAP2file interpretation, and data management. Softwareshould have a friendly man-machine interface and a certain degree ofreliability and real-time capability.Preliminary testing and verification has done to the calibration system atthe end. Application program is developed through automatically generatedcode from the Simulink model, and then it is integrated with CCP driver asthe object of calibration system. Analysis of the calibration system’sgenerality performance is carried out through research in the process frommodel design to calibration stage. Proper testing methods are design for theexperiment. The test results show that the functions of the calibration systemwork correctly and it is stable and reliable to use. The software’sman-machine interface and convenient operation prove calibration processcan be well completed and real-time capability meets the system requirement.