Design And Implementation Of Calibration System Based On XCP Protocol

In recent years, with the progress and development of automotive electronics technology,there are growing numbers of electrical and electronic equipments used in the automotivesector, this adds a lot of safety and comfort features for the modern automobile, greatlyimproving scientific and technological content of the vehicle, making the car itself moreintelligent and humane. Using a large number of electronic control units on the automotiveindustry has made a revolutionary breakthrough, making the car closer to the needs of users asa commodity, but it also increases the difficulty of development of the engine control unit atthe same time. To coordinate communication between the electronic control unit and othercontrollers, and exhaust gas emission targets specified in line with relevant laws andregulations, the engine control unit requires a large number of dynamic process managementand optimization. This need to find an effective way to change the observation of thesecontrol variables, so the XCP protocol came into being as a calibration process specificationin a variety of bus transport and communications, greatly reducing engine R&D cycle.Calibration system as a part of the master control unit, adjust the control variables to find anoptimal combination of points in terms of stability, security, and dynamic engine. Thedevelopment of Calibration system has a profound effect on researching in ECU, it hasbecome the focus of attention of the major car manufacturers as well as related R&Ddepartment.The work of this thesis is built around “Design and Implementation of CalibrationSystem Based on XCP Protocol”. Firstly, starting from the architecture of the calibrationsystem, calibration system is divided into the protocol processing module, the transmissiondata processing module, the generic driver modules and calibration environment configuration.Through further study and research relevant background knowledge, understanding XCPcalibration protocol specification and transmission processes, design and implement aprotocol handler, including the establishment of communication links, and communicationssecurity access, calibration data download and online calibration function. Secondly, startingfrom the CAN bus transfer mechanism, combined with the functional requirements ofcalibration system and data transmission characteristics, a completed the task of systemtransport layer. Including the bus to send and receive packets of information and to downloadthe data group packet processing sub-module. According to the understanding of the maincontrol chip (TC1767) data manual, achieved its module universal driving. Finally, the combination of demand and calibration system features to optimize the structure of the codeand the interface between each module, and the components on the functionality andperformance test, the successful realization of the calibration system based on XCP protocol.The first chapter of this thesis describes the development background and research statusof the calibration system. This section highlights the practical significance of the system andthe importance of the development process of automotive electronic control unit, andsummarizes the general terms of the structure and function of the calibration system. Finally,introduce the main contents of this article.The second chapter of this thesis introduces on the communication protocols andtransmission bus. This section is to compare and analyze two data acquisition modes of theXCP protocol, a brief description and characteristics of the CAN bus and packet structure.The communication part of the agreement, including the transmission of the XCP protocolspecification, namely the transport layer and physical layer independent of the XCP protocolcan be transmitted in the CAN, LIN, USB, etc. on the bus; protocol specification describes thetransmission packet types and transmission in the communication process command; interfacedefinition describes the ASAP2of the database file used in the calibration process.The third chapter of this thesis is the needs analysis of the calibration system. The needsanalysis is to design and implement the necessary work of a calibration system, it also toensure that the calibration system to complete the key to quality. Calibration System in thischapter for XCP, respectively, from the master chip select, calibration protocol, real-timereliability, system functions and system configuration environment aspects described anddemonstrated.The fourth chapter of this thesis is an overview of the calibration system; this chapterbegins with a brief analysis of the calibration mode of communication, configuration,environment, and key technologies. Calibration and software architecture of the systemanalysis and design at the application layer, including the initialization module, system taskmodule and calibration data module. Calibration component protocol processing layerincludes a packet buffer settings and data stream processing. The underlying driver partFLASH drive and the functionality of the CAN driver function. XCP command processorinclude the protocol handler and the various sub-function of the command function. Duringthe execution of the entire system is divided into the following phases, the first componentstarts the clock and register initialization, followed by the various functional modules to beinitialized, start the scheduler perform a periodic task. CAN network data stream processingsection in the CAN interrupt service routine to extract data, group packages and transportlayer. XCP protocol processor part, respectively, for security access, calibration datadownload, online data observations core module design and realization.The fifth chapter of this paper details the core module of the calibration system. Thetransmission of the XCP protocol layer packet structure definition, demarcation of the basic commands, command parsing process, and core functions to achieve the analysis and design.Depth calibration system to establish communication links, communication security access,calibration data download and data-line calibration function modules. Finally, this chapter isdesigned and implemented the driver function of the FLASH module and the CAN module.The sixth chapter of this thesis introduces the calibration system based on XCP protocoltesting and debugging. This chapter focuses on the functionality and reliability of thecalibration system is tested and analyzed. According to the function demand of design andvalidate a calibration assembly for test case. This paper introduces the test of related testingmethods and test results, and the test results are analyzed.The seventh chapter summarizes and prospects, this text has completed work andtheoretical innovation in content, and the calibration system development direction in thefuture as briefly.