Study On Engineering Control System For Hybrid Electric Bus

With energy crisis and the increasingly large fuel consumption in the department ofurban transportation, it is an urgent work to develop low energy consumption technology. Inthis context, hybrid electric vehicle which combines the advantages of conventional vehicleand electric vehicle is the most promising low-power and low-emission vehicle nowadays.Compared with other vehicles, urban bus has notable features of relatively fixed drivingconditions, low average velocity, various load, high fuel consumption and high emissions. Soapplication of hybrid technology to achieve energy conservation has more practicalsignificance.As a common key technology and core component of electric vehicles, the technicallevel of vehicle control system has a direct impact on the power performance, safety and fueleconomy of electric vehicles. At present, the field of development of electric vehicle controlsystem (VCU) abroad tends to be mature that the control strategy is with high maturity,vehicle energy saving performance is notable and the reliability of controller product isconfirmed through market test. There is still a big gap in the field of vehicle controllingbetween domestic and foreign in many aspects such as mostly functional development, badenergy saving effect, the lack of verification and testing instruments, the lack of managementtools for mass production and the lack of experience in developing engineering productionoriented system. The research work of this paper is to overcome the above deficiencies ofvehicle control systems, especially in the urgent task of developing engineering productionof control system. This thesis relates to vehicle modeling, development and test of energymanagement strategy, bench test and vehicle validation, condition calibration and themanagement of vehicle off assembly line in mass production, which covers a wide range andcontain much complexity. The full paper contains the following six aspects.1. Through analyzing the problem exiting in the industrialization of vehicle controlsystem for hybrid bus, combined with consulting amounts of literature data at home andabroad, this paper sorts out the key technology of parallel hybrid bus control system,determines the research contents, and analyzes the research situation and researchsignificance of this problem.2. Simulation platform for hybrid electric bus modeling was studied based oncommercial simulation software CRUSE，and the vehicle mathematical modeling andtreatment methods were focused on. A forward simulation platform combined CRUSE andSIMULINK was established. In order to eliminate errors between simulation and real vehicletest, the characteristic and parameters of simulaton platform were modified by analysisingthe difference between simulation results and corresponding real vehicle test data. A basic functional verification environment for early rapid control strategy development of hybridelectric bus or energy management was formed.3. In this paper, an engineering-oriented control strategy for hybrid electric bus has beenstudied. After analyzing all work modes of hybrid electric bus, the energy managementstrategy was developed based on rule-based multi-mode layered logic rule. And the energymanagement strategy was optimized through bench test and vehicle test.4. The complexity of hybrid bus system has led to the difficulty of the testing andverification of vehicle control strategy. In order to ensure the reliability and security ofhybrid control system, According to mutative requirement of different stages in the entirevehicle control system development, the offline simulation, HIL simulation and real vehicletest have been carried out in this paper. The requirements of the reliability of product controlstrategy development and the development cycle have been met. And all the researchprovides a quality guarantee for FAW hybrid electric bus.5. Based on the parameters modular and platform concept, the HCU calibration systemfor the hybrid electric bus is developed with CCP protocol. A CANape calibration tool wasused to complete the calibration research on hybrid electric bus, especially against the highfuel consumption in the city cycle. And the result of calibration shows performancepromotion with5%reduction of fuel consumption, which will push forward theindustrialization of FAW hybrid electric bus.6. Under the needs of hybrid bus production and operational maintain, a fully functionalvehicle end of line (EOL) detection system and remote monitoring system have beendeveloped. And the EOL system will significantly save the time wasted in hybrid bus off theassembly line, improve production efficiency and reduce the failure rate of the hybrid buses.The remote monitoring system can be real-time monitoring of the hybrid bus demonstrationrun state, which evidently improves bus-oriented remote diagnostics and service capabilities.This article is part of the research content of electric vehicle major specific projects‘Development of the new vehicle technology of FAW JieFang hybrid bus’ and ‘Research ofthe industrialization technology of JieFang moderate hybrid bus’.The study of this article isfor productization practice of hybrid vehicle control system. In order to further improve thetechnical maturity of the hybrid bus control strategy, to break the technology monopoly offoreign countries, to format core competitiveness of production with proprietary intellectualproperty rights, to better meet the needs of consumers and market, so as to provide technicalsupport of realizing large-scale industrialization development.The innovation of this article is, based on the developing thought of modularization andplatformization, using the advanced control system developing methods to realize buildingof test environment model, development of the vehicle energy management strategy,hardware-in-the-loop test of the control strategy, systematic development of the vehiclecalibration system and vehicle off-line test system, and the vehicle off-line test system which is developed and applied to reality for the first time in the field of hybrid productionmanagement in China.