基于驾驶风格识别的混合动力汽车能量管理策略

为了进一步提高混合动力汽车的燃油经济性,针对驾驶员的驾驶风格对混合动力汽车的燃油经济性有较大影响的问题。通过对驾驶操作引起的汽车行驶过程的车体冲击度分析,确定不同类型行驶工况下的驾驶风格区分方法,应用该方法在所采集的大量行驶工况数据上,得到不同驾驶风格的车速信息。将行驶工况识别算法、不同驾驶风格的车速信息、等效燃油最小能量管理策略相结合,获取不同驾驶风格下的最优需求功率分配方式,从而建立基于驾驶风格识别的能量管理策略。对一段随机工况应用所制定的能量管理策略,仿真结果表明,所提出的控制策略比不考虑驾驶风格的等效燃油最小能量管理策略燃油经济性提高了8.47%,发动机工作点更好地运行在其最佳效率曲线附近,电池SOC更稳定且更好地维持在高效区域。     

基于Visual Basic卡车循环运输工况燃油经济性分析

燃油经济性是车辆的主要使用性能之一,降低油耗是运行成本控制的重要来源.针对井下运输卡车循环运行工况的特点,建立工作循环示意图,获取八工况各自的燃油消耗量;采用循环行驶计算法,测定运输卡车的燃油经济性,建立整车运行燃油消耗的数学模型.基于编程语言VB (Visual Basic)建立卡车燃油经济性系统分析模块,分为参数输入端和燃油进行性指标输出端.分析不同车型、井道斜坡道坡度、循环运输量等对燃油经济性的影响.采用发动机燃油测试评价试验台,分析不同转速和负载条件下,发动机的比油耗,并与系统模拟结果进行对比.结果 可知:所研究车型每吨矿公里的燃油消耗量为0.156L,每天的生产效益为96.8万元,燃油消耗高但整体运行的经济效益也高,适合作为该矿区的工况下的运输车型;当坡度为15％时,卡车每天油耗量达到最大值;当载重量为30t时,该运输卡车的经济效益最大化;试验测试与系统模拟结果误差在7％以内,油耗的变化趋势保持一致,表明系统模块结果的可靠性与准确性.分析内容和结果为此类设计提供重要参考.     

汽车节能驾驶实时控制模型的构建与实验方法研究

驾驶行为对汽车运行燃油消耗有重要的影响,规范驾驶行为,实现节能驾驶是汽车节能的必然途径。从分析典型汽车行驶工况入手,根据不同行驶工况下的汽车能耗模型,以能耗最小为目标,构建了汽车节能运行计算模型,基于模型预测、神经网络等理论,提出了面向汽车节能驾驶的燃油消耗在线优化、预测控制和反馈校正方法,建立了汽车节能驾驶实时控制模型,描述了汽车节能驾驶虚拟实验平台和实车实验系统的基本框架,以实现汽车节能驾驶实时控制模型的评价、验证和优化。     

四轮驱动混合动力轿车经济性换挡规律研究

考虑电机和电池系统的影响,对四轮驱动混合动力汽车进行了经济性换挡规律的研究。通过计算瞬时输出功率下各动力源的等效燃油消耗,让车辆行驶在综合等效油耗率最低的挡位,从而实现了整车燃油经济性最优的目标。运用MATLAB建立整车模型,仿真分析了整车各种驱动模式下的经济性换挡规律,并通过实车试验验证了所提出的经济性换挡规律的有效性。     

基于车速跟踪的商用车燃油经济性建模与仿真

针对燃油经济性仿真模型仅能计算车辆在模态工况下的燃油消耗量的问题,提出了一种基于车速跟踪的燃油经济性仿真模型的建模方法。在建立车辆纵向动力学模型、驾驶意图模型和发动机与传动系统模型的基础上,利用MATLAB/Simulink搭建了商用车燃油经济性仿真模型,并以某客车为例进行了试验与仿真对比。对比结果表明：所建模型能对商用车的任意行驶工况进行较好的车速跟踪,并能对商用车在该行驶工况下的燃油消耗量进行较为准确的仿真计算。通过更改仿真模型中的相关车辆参数,可以方便快速地进行不同动力总成配置的商用车的燃油经济性仿真计算。     

基于VB语言的汽车燃油经济性分析的可视化研究

建立了汽车燃油经济性分析的数学模型,利用VisualBasic语言开发了仿真程序。以某一车型为例进行仿真,根据发动机的外特性、汽车的功率平衡和发动机的负荷特性,得到汽车整车的等速百公里油耗和六工况循环油耗等参数,与实际结果吻合较好。仿真结果不仅可以快速精确地获得汽车燃油经济性分析的相应数据和图形,而且使工程技术人员从繁杂的高强度劳动中解脱出来,使其有精力和时间投入到新的工作中。     

汽车技术状况对油耗的影响

汽车已从最早的运输方式发展为一种生活方式,市场也在不断扩展和创新,消费者对汽车的需求也呈现出各种发展趋势,消费者生活质量的不断提高,对汽车性能的选择也有了更高的要求。当今市场上的汽车以使用燃料为车辆提供动力的传统加油车为主导,车辆的燃油经济性已成为人们关注的重要汽车性能。评估车辆燃油经济性的主要指标是车辆每100公里的燃油消耗。汽车油耗与车辆的技术状况密切相关。为减少汽车油耗,有关技术人员应对汽车技术条件和油耗问题的研究,提高汽车运行性能、环境保护和经济可行性。     

基于等效油耗最小的四驱混合动力汽车能量管理

提出了一种基于遗传算法优化的四驱混合动力汽车等效油耗最小控制策略。针对四驱混合动力的特点,建立了整车动力学模型,设计了基于等效油耗最小的瞬时能量管理优化策略。为进一步提高四驱混合动力汽车的燃油经济性,采用遗传算法优化了等效油耗最小策略的关键参数。硬件在环仿真结果表明,基于遗传算法优化的等效油耗最小策略可以实现整车能量优化管理,与基于规则的能量管理策略相比,其在典型工况下的平均燃油经济性高8.94%,比优化前的等效油耗最小策略的燃油经济性高2.68%。     

基于多目标优化的传动系速比匹配方法研究

为在汽车开发过程中最大限度的降低整车燃油消耗,对整车传动系速比进行了优化匹配。用试验标定Cruise整车仿真模型,联合Isight多目标优化软件对汽车传动系速比进行了多目标优化,获得了汽车动力性与燃油经济性的C曲线。结果表明,在不牺牲汽车动力性的前提下,优化后NEDC工况的综合油耗降低了约0.1 L/100 km,为公司节省了油耗成本。     

同轴并联式混合动力汽车模糊控制策略研究

为了提高同轴并联式混合动力汽车的燃油经济性,针对同轴并联式混合动力系统的结构特征、工作过程及能量流动模式,以驾驶意图作为模糊设计的输入变量,对驾驶意图进行模糊识别。在Matlab/Simulink中建立基于驾驶意图识别的模糊控制转矩分配策略,并在NEDC循环工况下与Cruise进行联合仿真。结果表明,该控制策略在满足动力性的前提下,同基于逻辑门限值的转矩分配控制策略相比,能有效改善发动机的工作点,百公里综合油耗下降了3. 2%,进一步提高了整车燃油经济性。     

Car Fuel Economy Simulation Forecast Method Based on CVT Efficiencies Measured from Bench Test

Researchers face di culties in studying the e ects of driveline e ciency on car fuel economy via bench and road tests because of long working periods, high costs, and heavy workloads. To simplify the study process and shorten test cycles, a car fuel economy simulation forecast method for combining computer simulation forecasting with bench tests is proposed. Taking a continuously variable transmission(CVT) as the research object, a transmission e ?ciency model based on a bench test is constructed. An optimal economic variogram based on the original CVT vari?ogram, the boundary conditions of vehicle performance, the road conditions and the driving behavior of the driver is generated in the Gear Shift Program(GSP)?Generation module in AVL Cruise. And on this basis a driveline simulation model that can calculate the fuel consumption based on the driveline data of a test car is built. The model is used to forecast fuel consumption and calculate real?time CVT e ciency under di erent conditions. Contrastive analyses on simulation results and real car drum test results are made. The largest error between simulation results and drum test results in driving cycles is 4.099%, which is 5.449% under constant velocity condition in driver control mode and 4.2% under constant velocity condition in automatic cruise mode. The results confirm the feasibility of the method and the good performance of the driveline simulation model in accurately forecasting fuel consumption. The method can e ciently investigate the e ects of driveline e ciency on car fuel economy. Moreover, this research provides instruc?tion for accurately forecasting fuel economy as well as references for studies on the e ects of drivelines on car fuel economy.     

Car Fuel Economy Simulation Forecast Method Based on CVT Efficiencies Measured from Bench Test

Researchers face difficulties in studying the effects of driveline efficiency on car fuel economy via bench and road tests because of long working periods, high costs, and heavy workloads. To simplify the study process and shorten test cycles, a car fuel economy simulation forecast method for combining computer simulation forecasting with bench tests is proposed. Taking a continuously variable transmission (CVT) as the research object, a transmission efficiency model based on a bench test is constructed. An optimal economic variogram based on the original CVT variogram, the boundary conditions of vehicle performance, the road conditions and the driving behavior of the driver is generated in the Gear Shift Program (GSP)-Generation module in AVL Cruise. And on this basis a driveline simulation model that can calculate the fuel consumption based on the driveline data of a test car is built. The model is used to forecast fuel consumption and calculate real-time CVT efficiency under different conditions. Contrastive analyses on simulation results and real car drum test results are made. The largest error between simulation results and drum test results in driving cycles is 4.099%, which is 5.449% under constant velocity condition in driver control mode and 4.2% under constant velocity condition in automatic cruise mode. The results confirm the feasibility of the method and the good performance of the driveline simulation model in accurately forecasting fuel consumption. The method can efficiently investigate the effects of driveline efficiency on car fuel economy. Moreover, this research provides instruction for accurately forecasting fuel economy as well as references for studies on the effects of drivelines on car fuel economy.     

Lifetime Evaluating and the Effects of Operation Conditions on Automotive Fuel Cells

Lifetime is one of the important indicators of automotive proton exchange membrane fuel cells. People used to evaluate the lifetime of vehicular fuel cells by laboratory tests or road tests that usually take thousands hours even years. In order to achieve a rapid evaluation technique and to seek lifetime extension methods, a lifetime calculation formation was drawn out in consideration of the vehicle driving cycle and the working condition factors. Bench experiments were individually carried out on two fuel-cell stacks same as ones applied on vehicle, and the performance decay rates of the two stacks were obtained under four operation conditions of changing load cycle, start-stop cycle, idling and heavy load. As a result, the predicted lifetimes rather conform to the actual running status in road test. And the research on the fuel cell performance decay rates under different load conditions was also done. Consequently, an unexpected finding was discovered that operating under micro-current has an effect on recovering fuel cell performance. The vehicle fuel cell rapid assessment method only requires four laboratory tests of driving cycle, load cycle, idle operating conditions and heavy load conditions, and the whole process merely lasts less than 250 h. These experimental results can be used to predict the vehicular fuel cell lifetimes on various utility models or driving cycles, therefore to optimize the application model to prolong the fuel cell lifetime. Actually in the experiment, it has already been proved successfully that the fuel cell lifetime could be extended from 1 100 h to 2 600 h by optimizing operating mode. The quick evaluation method is helpful to develop extended life fuel cell and to deplete fuel cell for a longer time.     

城市道路的燃油经济性分析

汽车燃油消耗量与发动机类型、制造工艺状况、道路条件、气候情况、海拔高度、驾驶技术等多种因素有关,对于城市道路中,停车怠速、汽车空调及制动能量损耗对于车辆的燃油经济性有重要的影响。对于城市这三个主要因素做出相应的分析。     

Work and speed based engine operation condition analysis for new European driving cycle (NEDC)

In order to evaluate fuel consumption and tailpipe emission of a vehicle, standard driving cycles are used to prescribe vehicle driving condition such as speed, gear shift, fluid temperature and so on. New european driving cycle (NEDC) has prevailed as the only driving cycle for emission and fuel consumption while Federal Test Procedure 75(FTP-75) mode is used in the United States. In South Korea, NEDC is applied for emission certification and FTP-75 mode is used for fuel consumption of a vehicle powered by diesel engine. Because these driving cycles are mixed of static phase (cruising and idle) and transient phase (acceleration and deceleration), they need to be transformed to static engine operation condition so that optimization is possible using engine dynamometer for each representative engine operation condition. This study set up two models to convert vehicle driving conditions to engine operation condition based on work which the engine should produce to follow the driving cycle and based on representative vehicle speed of NEDC. Accuracy of each model was compared with actual vehicle test result on a chassis dynamometer and the characteristics of each model were analyzed.     

混合动力汽车动力性和经济性道路试验

结合混合动力汽车的特点,根据传统汽车试验标准并参考SAE J1711混合动力轿车试验方法对EQ7200HEV第一轮样车进行了道路试验。试验包括0～100 km/h加速试验、最高车速试验、最大爬坡试验及ECE15工况燃油经济性试验等。试验结果表明,试验样车可以合理、准确的实现多工况切换与控制功能,燃油经济性与基础样车比较有所提高,但需在第二轮开发时重点提高动力性、经济性方面的研究。道路试验为样车参数标定、控制策略优化及系统匹配提供了理论依据,同时对混合动力汽车试验方法进行了有益的探讨。     

基于LVQ工况识别的混合动力汽车自适应能量管理控制策略

为提高混合动力汽车的燃油经济性,选取6种典型行驶工况代表“市区”、“郊区”和“高速公路”3类主要工况,采用基于规则的模糊能量管理控制策略,以整车燃油经济性为目标,在3类主要工况下用改进型粒子群优化算法优化发动机联合工作曲线与发动机关闭曲线系数,得到相应的优化后的隶属度函数的参数;运用学习向量量化(LVQ)算法识别车辆运行工况,动态选择相应的模糊控制策略,使混合动力汽车控制策略对选定的几种代表性工况具有自适应性,从而提高整车的燃油经济性。仿真对比结果表明,相比于传统混合动力汽车,燃油经济性提高了3.4%。     

汽车转向系统的故障诊断与维护

汽车转向系统一直是汽车研究者重点考虑的一个系统,该系统直接关乎到汽车驾驶的安全性与舒适性,随着时代的发展,人们越来越重视汽车的转向系统,汽车转向系统经过不断改进来满足人们的需求,传统的机械式转向系统是目前电动液压助力转向系统、电动助力转向系统研究、检测的基础,因此本文重点阐述了转向系统的发展、故障现象及原因,以及日常维护,对于今后从事汽车转向系统研究与维修人员提供理论指导。     

OPTIMIZATION APPROACH FOR HYBRID ELECTRIC VEHICLE POWERTRAIN DESIGN

According to bench test results of fuel economy and engine emission for the real power-train system of EQ7200HEV car, a 3-D performance map oriented quasi-linear model is developed for the configuration of the powertrain components such as internal combustion engine, traction electric motor, transmission, main retarder and energy storage unit. A genetic algorithm based on optimization procedure is proposed and applied for parametric optimization of the key components by consideration of requirements of some driving cycles. Through comparison of numerical results obtained by the genetic algorithm with those by traditional optimization methods, it is shown that the present approach is quite effective and efficient in emission reduction and fuel economy for the design of the hybrid electric car powertrain.