【作者】 孙强；

【导师】 李国祥；

【作者基本信息】 山东大学 ， 热能工程， 2014， 博士

【摘要】 混合动力总成匹配技术是混合动力汽车研发过程中最为核心的技术之一,本文依托国家科技支撑计划项目“通用的商用车与工程机械模块化混合动力总成”,对压缩式环卫车的混合动力总成从方案制定到样车试验的整个匹配过程进行了以下研究工作：1.压缩式环卫车典型工作工况的构建不同类型车辆在不同城市中的工作工况有其特有的特点,通过构建西安市压缩式环卫车典型工作工况,统计得到车辆实际工作过程中动力系统常用工作区域,为动力总成系统匹配设计、控制策略的化以及整车经济性评价提供依据。为完成对环卫车工况数据的采集,本文开发了车载远程监控系统,实现对车辆工况数据的远程采集；结合西安市道路特点和环卫车工作特点,优化选择测量道路和测量时间；在基于测试数据进行典型工作工况构建的过程中,针对现有的研究集中于运动学片段分类而对片段抽取鲜有研究的事实,本文提出一种两阶段聚类法用于完善运动学片段的抽取过程。为验证本文所提方法的有效性,基于同样的测试数据,分别利用本文所提方法和传统方法构建典型工作工况,分别利用散点分布、概率密度分布、联合概率密度分布和建模仿真的方法对两工况进行对比。对比结果表明,利用两阶段聚类法构建的典型工作工况,在速度和加速度的概率密度分布上有56.2%和80.1%的改进,在速度-加速度联合概率密度分布上有29.9%的改进,在装载、加速、匀速及减速阶段油耗百分比上分别有0.71%、0.53%、0.77%和0.47%的提高,各阶段油耗与实测油耗差异百分比上分别有2.15%、1.24%、1.59%、12.86%和15.72%的提高。2.压缩式环卫车混合动力技术仿真研究结合典型工作工况,通过常规动力环卫车结构及工作过程的分析,找出常规动力环卫车燃油消耗率高的根本原因在于：行驶工况和装载工况对动力总成的动力性需求存在巨大的差异。结合环卫车结构和混合动力系统特点,参照混合动力技术的结构分类,设计四种应用于压缩式环卫车的混合动力总成方案。结合环卫车行驶工况和装载工况对动力总成动力性的需求,对四种方案在压缩式环卫车上的适用性进行对比和分析,最终确定一种电机前置的单轴并联式混合动力方案。结合单轴并联式混合动力总成结构和环卫车实际工况,定性地论证了混合动力技术可以提高环卫车的经济性。通过Cruise和Matlab/Simulink联合仿真技术来定量的验证混合动力技术对整车经济性的改善情况。在Cruise中建立环卫车行驶工况模型,在Matlab/Simulink中建立装载工况模型,通过Cruise和Matlab/Simulink联合仿真模拟环卫车的整个工作工况。利用上述方法,建立环卫车的常规动力模型并进行仿真,通过对各阶段仿真油耗和实测油耗的对比,验证模型的准确性,对比结果表明：行驶工况油耗偏差8.09%,装载工况油耗偏差3.97%,总油耗偏差6.35%,所建立模型具有较高的准确性。在环卫车常规动力模型的基础上,保持除动力总成外的其他结构不变,仅对动力总成按照混合动力总成结构进行更改,完成环卫车混合动力模型的建立。以本文构建的典型工况为目标工况,对环卫车的常规动力模型和混合动力模型进行仿真,对比仿真结果中发动机工作点的分布和各阶段油耗,定量地确定混合动力技术对经济性的改善效果：在行驶工况中,混合动力系统中发动机46%的工作点燃油消耗率低于210g/kw·h,常规动力系统中发动机仅有25%的工作点燃油消耗率低于210g/kw·h,发动机整体工作效率显著提高：在装载工况中,常规动力系统耗油1.87kg,而混合动力系统耗油0.96kg,发动机油耗量显著降低；综合整个工况,混合动力系统使整车燃油经济性提高25.8%。3.压缩式环卫车混合动力总成控制策略研究结合混合动力总成结构及实际工况需求,分析混合动力总成的驱动模式及能量流动路径,获得该总成的全过程能量传递路径。在此基础上参照发动机燃油消耗率的定义,引入系统燃油消耗率的概念用以描述混合动力系统的燃油经济性,结合系统全过程能量传递路径,建立单轴并联式混合动力系统在不同工作模式下系统燃油消耗率的数学模型。基于以上工作,在Matlab/Simulink中实现基于系统燃油消耗率最低的瞬时优化策略,并将该策略与第三章中建立的环卫车混合动力模型集成。最后通过仿真对本文所提控制策略进行有效性验证,验证结果表明：在环卫车典型工作工况下,与采用基于规则的逻辑门限控制策略相比,采用基于系统燃油消耗率最低的瞬时优化控制策略能够使整车燃油经济性提高2.97%。4.混合动力总成系统开发试验台的设计与开发本文在对混合动力总成结构及混合动力总成控制流程分析的基础上,将试验台划分为四个模块：驾驶室模拟模块、动力系统模块、阻力系统模块和采集控制模块。驾驶室模拟模块的功能是：获取当前时刻的目标车速并将其和当前车速作比较,根据比较结果控制动力系统模块,实现目标车速；动力系统模块的功能是：接受驾驶室模拟模块的信号并输出相应的动力；阻力模拟模块的功能是：根据当前的车速、道路坡度等模拟车辆的行驶阻力；采集控制模块的功能是：对整个台架运行信息进行采集,并对整个台架进行必要控制。模块功能确定以后,根据每个模块的功能分别进行硬件和软件设计。特别值得一提的是,为获得动力总成所有的控制权限,本文自主设计与开发了台架上的整车控制器,其主控单元采用STM32F103处理器,其软件基于嵌入式操作系统uC/OS-Ⅱ开发,通过该整车控制器实现了对台架主要设备的集中控制。试验台完成后,通过标准工况试验对台架的设计功能进行验证。最后,在不改变试验台硬件的前提下,通过对试验台软件的更改,为试验台扩展了硬件在环测试和瞬态工况测试功能。最后,对本文所匹配开发的混合动力压缩式环卫车进行实车道路试验,试验结果表明：采用混合动力总成后车辆的主要动力性指标,最高车速、0-50km/h加速时间、4%坡度持续速度、最大爬坡度,均达到设计指标且不低于采用常规动力系统的原车；采用混合动力总成后车辆的经济性提高了33.78%,达到了经济性提高20%的设计目标。更多还原

【Abstract】 Hybrid powertrain matching technology is one of the most important technologies during the hybrid electric vehicle development process. This paper was financially supported by the National Key Technology R&D Program," Universal Modular Hybrid Powertrain of Commercial Vehicles and Construction Machinery ", expounding the entire matching process from scheme establishing to prototype testing. The main works of this paper are as follows:1. Working Cycle Construction Based on Experimental MeasurementWorking cycle, known as the reference of developing new vehicles and new technologies, is mainly used for fuel consumption testing and emission testing of vehicles. In theory, working conditions vary with vehicles in different regions during different time periods. Namely, it means that there isn’t exist a standard working condition that can describe the work cycle of all kinds of vehicles in any regions during any time perfectly.In addition, working cycles of common road vehicles only contain driving cycles. Besides the driving cycle, the working cycle of the compressing sanitation truck studied in this paper also contains the loading cycle during which the compressing sanitation truck completes collecting and compressing sanitation. Up to now, almost all the researches about construction of working cycles are aiming at driving cycle construction, and there is no public research work on the construction of compressing sanitation trucks’work cycle.In view of the two reasons we talked about, the typical working cycle of the compressing sanitation truck was constructed. To collect the working condition data of compressing sanitation trucks, the paper developed an on-board remote monitoring system, which used the CAN bus and other sensors to collect the vehicle’s working state data transmitted to monitoring center through GPRS. The measuring area,the measuring road and the measuring time were programmed reasonably based on the features of Xi’an city’s roads and the compressing sanitation truck’s characteristics. Specifically, the measuring area covered the typical urban areas, including commercial districts, residential quarters and industrial zones. The measuring road went through urban main road, urban secondary road and outer ring road. The measuring time selected both traffic peak time and slack time. In this case,12,000groups of data were gained in total, in the tests extending792.3km during7days.So far, the existing researches have focused on Fragment Classification in kinematics, while few studies are taken up with Fragment Extraction. Therefore, this paper presents a two-stage clustering method in the process of generating the typical working condition on the basis of the test data, used to perfect the extraction process of kinematics fragments. To verify the effectiveness of the proposed method, this paper sorted the same test data using the proposed method and traditional method to build a typical working condition respectively. Then the two typical working conditions were compared with each other via methods of the scatter distribution, the probability density distribution, the joint probability density distribution, the modeling and simulation in turn. The comparison showed that the typical working condition applying two-stage clustering method had56.2%and80.1%improvements in the probability density distribution of the velocity and acceleration,29.9%improvements in the joint probability density distribution of the velocity-acceleration. Moreover, the fuel consumption of loading, accelerating, constant speed and decelerating phase increased respectively by0.71%,0.53%,0.77%,0.47%on the percentage, the differences between fuel consumptions of each stage and the measured fuel consumption improved by2.15%,1.24%,1.59%,12.86%,15.72%on the percentage.2. The Simulation Study of Hybrid Compression Sanitation TrucksCombined with the typical working conditions, the paper analyzed the structure and working process of traditional dynamic sanitation trucks to find out the basic cause of traditional dynamic sanitation trucks with high fuel consumption. There were two reasons why traditional dynamic sanitation trucks had high fuel consumption. First, the demands for power performance of driving condition and loading condition varied greatly. Second, the engine acted as the only power source for whole vehicle. In order to guarantee the normal work of the whole working conditions, the engine was demanded to meet the higher requirement for power performance, the one of driving condition. Consequently, the engine worked at a low load under high fuel consumption for a long time in loading condition, which led to the inefficiency of the whole working conditions. Hybrid technology had the native advantage of facing such problems:an integration of several power sources in essence, complementing every power source to achieve an efficient overall characteristic. Owing to multiple power sources in the hybrid powertrain, composition structure of powertrain had more schemes for supply. How to choose the optimal hybrid structure is the first problem faced in hybrid powertrain matching process.Referring to the actual structure of sanitation trucks and the structure classification of hybrid technology, four hybrid powertrain solutions applied to compression sanitation trucks were designed in this paper. Based on the demand for power assembly of sanitation trucks under driving conditions and loading conditions, the paper compared and analyzed the applicability of four solutions for compression sanitation trucks, and ultimately determined a prepositional motor single-axle parallel hybrid solution.It was demonstrated qualitatively that hybrid technology can improve the economy of sanitation trucks, combined with the structure of the single-axle parallel hybrid power assembly and the actual working conditions of sanitation trucks. In the absence of real vehicles, how to describe quantitatively the economy improved by hybrid technology became the second problem in the matching process of hybrid power assembly.The behavior of the static vehicle could not be simulated in Cruise. It meant that the loading conditions of sanitation trucks could not simulated in Cruise either. The second problem mentioned before had been solved through Cruise and Matlab/Simulink co-simulation technology, by which the whole working conditions could be simulated. Among them, the driving condition model was established in Cruise, the loading condition was established in Matlab/Simulink. Then traditional model of sanitation trucks was established and simulated. Finally the accuracy of the model was verified through the comparison between the simulated fuel consumption and the measured fuel consumption, results of the comparison showed that fuel consumption under driving condition deviated with a rate of8.09%, fuel consumption under loading condition deviated with a rate of3.97%, the total fuel consumption deviated with a rate of6.35%. The model had high accuracy. On the basis of traditional model of sanitation trucks, the power assembly was altered according to hybrid dynamic vehicles, while other parts were left unchanged, thereby, the hybrid dynamic model was established. As the typical working conditions acted as the target conditions, the traditional model and the hybrid dynamic model were simulated. The effect on the economy of hybrid technology was described quantitatively comparisons of the distribution of engine working points and fuel consumptions of the various stages. In driving conditions, the overall efficiency of the engine improved significantly:it was46%of engine working points less than210g/kw·h in hybrid dynamic system, while there was25%in traditional dynamic system. In loading conditions, fuel consumption of the engine reduced significantly: fuel consumption of traditional sanitation truck was1.87kg, yet0.96kg of hybrid scheme. Integrated the whole working conditions, hybrid dynamic system improved fuel consumption by25.8%.3. Study on Power Management of Single-axle Parallel Hybrid CSTAfter the structure and parameters of the hybrid system were determined, the efficiency of the hybrid system was directly influenced by the power management strategy, so, the matching of power management strategy is one of the most important processes during developing new HEV. Based on the fact that logic threshold control strategy can’t fit the change of all work conditions, global optimization control strategy unable to practical application and fuzzy logic control strategy hard to realize in embedded real time systems, this paper paid attention on instantaneous optimization control strategy based on minimum system fuel consumption rate.Combined with structure analysis of the hybrid powertrain and real work condition requirements, this paper analyzed the drive mode and energy flow of hybrid power train and acquired the energy transfer path of the powertrain. Referred to the definition of engine fuel consumption rate, this paper imported the definition of system fuel consumption rate and used this definition to explain the hybrid system’s fuel economy. Based on the works mentioned above, established the mathematical model of different drive mode’s fuel consumption rate and realized instantaneous optimization control strategy based on minimum system fuel consumption rate in Matlab/Simulink. Finally, verified the effectiveness of the strategy. The results indicate that, compared with the logic threshold control strategy, by using the strategy that this paper established, the fuel economy improves2.97%.4. Design of Single-axle Parallel Hybrid Powertrain Test PlatformDuring the development of hybrid electric vehicle, bench test is of great significant to shorten the period of vehicle calibration and help the developer to reduce the costs and risks of the development of HEV In this paper, based on the characteristics analysis of single-axel parallel hybrid powertrain, the single-axle parallel hybrid powertrain test platform was designed and constructed by using modular design method.Based on the structure analysis of the hybrid compression sanitation truck, designed a single-axle parallel hybrid powertrain test platform. Modular design method was used to realize this platform and this platform was divided into four modules:driver simulation module, powertrain module, vehicle resistance simulation module, data acquisition and control module. This paper developed a vehicle control unit that used in the test platform. This HCU used STM32F103MCU as its processer and uC/OS-Ⅱ as its operating system. The Function design, software design and realization of the four modules are respectively discussed. Finally, by changing the software of the test platform, realized function expansion of the test platform.Finally, this paper verified the hybrid power train’s effectiveness by taking road tests of real hybrid compression prototype vehicle. The results of the road tests indicates that the hybrid vehicle’s power performances, such as maximum speed,0-50km/h acceleration performance, maximum gradeability and so on, all meet the design target; the hybrid vehicle’s fuel economy improves33.78%, exceeds25%which is the design target.更多还原