基于整车经济性的商用车传动系统匹配设计

商用车传动系统的匹配对于商用车的动力性、经济性有重要的影响。针对商用车的传动系统,从整车经济性的角度,通过性能计算、建立仿真模型模拟不同工况下的油耗,进行数据处理和分析,并结合市场需求,确定最优的匹配方案。     

我国轻型商用车三阶段油耗法规浅析

全球汽车油耗法规不断加严的背景下,我国汽车特别是轻型商用车油耗的加严也势在必行。为了更好地应对轻型商用车最新的第III阶段油耗法规要求,对法规进行了分析,包含法规的评价方法、与乘用车第IV阶段限值的对比。针对轻型商用车提出了从整车和发动机角度的节油技术措施,可实现185%的油耗改善,基本上能满足从第II阶段油耗向第III阶段油耗升级的要求。     

我国轻型商用车第Ⅲ阶段油耗法规浅析

全球汽车油耗法规不断加严的背景下,我国汽车特别是轻型商用车油耗的加严也势在必行。为了更好地应对轻型商用车最新的第III阶段油耗法规要求,对法规进行了分析,包含法规的评价方法、与乘用车第IV阶段限值的对比。针对轻型商用车提出了从整车和发动机角度的节油技术措施,可实现18.5%的油耗改善,基本上能满足从第II阶段油耗向第III阶段油耗升级的要求。     

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。     

某款轻型商用车降油耗方法

通过整车风阻系数、汽车轻量化和整车传动系速比优化,以及置换低滚阻轮胎等方法进行某款轻型商用车的燃油经济性提升。应用CFD数值模拟方法对某商用MPV车身进行空气动力学仿真及优化,并结合油泥模型风洞试验对降风阻效果进行验证;应用整车轻量化方案,以及使用低滚阻轮胎对整车的滚动阻力进行优化;通过传动系总速比优化,使该款商用车在NEDC的运行工况下更加接近经济区域。     

轻型货车辅助电动系统参数的优化匹配

针对轻型货车在运输时难以达到城市排放标准的问题,提出了一种基于传统货车底盘结构的辅助电动系统设计方案。在对国产某轻型货车辅助电动系统进行常规设计的基础上,利用遗传算法以提高整车经济性为目标,对该系统的关键参数进行优化匹配;利用AVL Cruise建立电动系统整车模型并对匹配前后的结果进行了仿真对比。结果表明,续驶里程得到较大提升且百公里耗电量有所降低,尽管损失部分动力性,但优化后整车性能均满足设计需求,验证了优化匹配方法的正确性,为轻型货车辅助电动系统的设计提供了依据。     

48V-BSG轻混系统整车性能影响分析

随着油耗、排放法规的日益严苛,客户群体对于驾驶感受要求持续提升,为满足油耗目标及优化驾驶性,传统内燃机电动化日渐深入,而48V-BSG技术对于传统乘用车油耗指标、排放指标、驾驶性指标改善具备较好的性价比。本文应用Cruise对某汽油发动机应用48V-BSG技术方案在某整车上进行整车性能仿真分析,研究各工况及控制策略下48V-BSG对于发动机摩擦功、整车经济性、动力性影响,并通过性能试验结果与仿真数据比较分析验证性能仿真分析结果。     

并联混合动力汽车动力系统匹配与控制研究

针对轻型商用车,进行了发动机轴动力组合式并联轻度混合动力驱动系统的开发,对动力系统关键零部件进行参数匹配和设计.设计了整车控制策略并利用dSPACE/Micro Autobox将经过MATLAB/Simulink离线仿真验证的混合动力汽车控制系统模型生成快速控制原型,并在实车状况下对控制系统性能进行了试验.试验表明所设计的控制系统性能满足设计要求,整车动力性及经济性有大幅提高.     

整车后桥异常噪声分析与优化

随着科技发展和社会的进步,厂家及乘客对商用车乘坐舒适性要求越来越高。汽车NVH性能和顾客对汽车总体评价密切相关。本文对后桥异常噪声产生机理和特性进行了分析,针对某商用车在中高速行驶工况噪声大故障为例,提出了解决该故障的诊断思路。通过NVH试验及频谱分析及滤波回放的Sound analysis方法,确定后桥噪声为整车噪声主要噪声源,其表现为多个倍频频率下的窄频噪声,后桥齿轮噪声主要是由于轮齿在啮合过程中产生"节线冲力"和"啮合冲力"所激起。通过优化后桥齿轮精度和重合度,试验结果表明,优化后驾驶员噪声主要频率125 Hz和250 Hz下声压明显减弱,驾驶员噪声降低2~3 d B(A),不仅降低了噪声值,而且整车异响消失,声品质也明显提升。     

功率分流式混合动力汽车整车参数匹配与优化研究

针对功率分流式混合动力汽车,首先根据整车设计参数及动力性能目标要求,分别对电机、动力电池组、发动机、主减速器和行星排等传动系统部件进行参数匹配,并运用AVL-Cruise软件建立目标车辆整车模型;其次在满足动力性能目标的前提下,运用AVL-Cruise和Isight软件搭建联合仿真模型,分别采用粒子群优化算法和多岛遗传算法,将行星排特征参数和主减速器传动比作为优化参数,百公里油耗和电耗加权之和作为优化目标进行优化研究,并对比分析2种优化算法的计算结果来获得兼顾动力性能和经济性的最优结构参数,为研究功率分流式混合动力汽车传动系统提供理论依据。     

基于随机动态规划的混合动力履带车辆能量管理策略

混合动力履带车辆采用发动机—发电机组和电池组混合供电,必须设计满足车辆动力性和燃油经济性约束的能量管理策略。针对串联式混合动力履带车辆,提出一种基于随机动态规划的能量管理策略设计方法。以实车行驶试验数据为目标工况,将驾驶员功率需求抽象为随车速变化的马尔科夫过程。建立发动机—发电机组、电池组以及直流母线功率平衡动态模型。以目标工况中燃油消耗及电池最终荷电状态的偏差作为车辆的优化控制成本函数,建立车辆能量管理最优控制问题。采用策略迭代法求解以发动机转速、电池组荷电状态、车速和驾驶员功率需求为输入、发动机电子节气门为输出的最优控制策略。所得控制策略通过基于前向车辆模型的仿真以及行驶试验验证。结果表明,相对于原发动机多点控制策略,所得最优控制在满足目标工况同时,燃油经济性明显提高。     

汽车动态油耗在线检测系统研究

随着我国汽车保有量的不断增加,燃油价格的不断攀升,汽车的油耗受到广大用户越来越多的关注。研发了一套汽车动态油耗存线检测系统,能方便获取车辆的瞬时油耗信息,累计试验过程中车辆的总油耗,建立温度补偿系统,根据小同的温度对试验数据进行修正,使获得的试验结果史精确可靠。     

基于CAN总线和SD卡的车载嵌入式系统

提出了一种基于CAN总线和SD卡的车载嵌入式系统的设计，其主要功能是记录车辆的油量信息，为车辆加油及燃油管理提供了一种很好的解决方案。系统通过多个CAN节点采集耗油、加油、回油和行车速度等数据参数，与主机采用CAN总线进行通信。主机具有流量计算、界面管理、参数设定、记录查询和故障检测功能，使用EEPROM作为内部存储器，用SD卡作为扩展存储器存储处理过的数据信息，以方便管理人员查询。     

Operation algorithm for a parallel hybrid electric vehicle with a relatively small electric motor

In this paper, operation algorithms for a parallel HEV equipped with a relatively small motor are investigated. For the HEV, the power assist and the equivalent fuel algorithms are proposed. In the power assist algorithm, an electric motor is used to assist the engine which provides the primary power source. In the equivalent fuel algorithm, the electric energy stored in the battery is considered to be an equivalent fuel, and an equivalent brake specific fuel consumption for the electric energy is proposed. From the equivalent fuel algorithm, distribution of the engine power and the motor power is determined to minimize the fuel consumption for a given battery state of charge (SOC) and a required vehicle power. It is found from the simulation results that the fuel economy and the final battery SOC depend on the motor discharge energy and it is the best way to charge the battery only by the regenerative braking, not by the engine to improve the overall fuel efficiency of the HEV with the relatively small motor.     

新型混合动力汽车工作模式分析与参数匹配设计

为降低制造成本,并实现混合动力汽车节省燃油和降低排放,提出了一种采用行星齿轮机构的新型混合动力汽车动力传动系统方案,进行了该系统方案的工作模式分析和参数匹配设计。在MATLAB/Simulink环境下利用整车动力学理论建模与关键零部件(如发动机、ISG电机、电池、变速器以及行星齿轮)数值建模相结合的方法,建立了基于该系统方案和设计参数的混合动力汽车整车性能分析模型,进行了整车动力性能和ECE_EUDC循环工况下的燃油经济性仿真计算分析。结果表明所设计的新型混合动力汽车参数设计合理,具有良好的动力性,燃油消耗较传统车下降36.8%,这为该系统方案的实施提供了理论依据。     

Evaluation of fuel economy for a parallel hybrid electric vehicle

In this work, the fuel economy of a parallel hybrid electric vehicle is investigated. A vehicle control algorithm which yields operating points where operational cost of HEV is minimal is suggested. The operational cost of HEV is decided considering both the cost of fossil fuel consumed by an engine and the cost of electricity consumed by an electric motor. A procedure for obtaining the operating points of minimal fuel consumption is introduced. Simulations are carried out for 3 variations of HEV and the results are compared to the fuel economy of a conventional vehicle in order to investigate the effect of hybridization. Simulation results show that HEV with the vehicle control algorithm suggested in this work has a fuel economy 45% better than the conventional vehicle if braking energy is recuperated fully by regeneration and idling of the engine is eliminated. The vehicle modification is also investigated to obtain the target fuel economy set in PNGV program.     

Optimal operation strategy development for fuel cell hybrid vehicle

An overall simulation model for fuel cell hybrid vehicle (FCHV) power train in parallel configuration using MATLAB/Simulink programming is constructed in this study. The model runs on power control strategy by using logic-threshold approach, achieved by the hybrid control unit (HCU) and fuel cell stack number. Using accelerator and decelerator pedal positions deduced from the driving schedule as the primary input, the simulation implements power flow and distribution under different vehicle operating modes. The HCU control strategy also incorporates regenerative braking and recharge for battery capacity recovery. Using the D-optimality method for experiment points selection and sequential quadratic programming (SQP) algorithm for obtaining the optimal operational parameters, three control threshold variables of HCU and optimal stack cell number are selected for hydrogen fuel economy under certain driving cycles. The proposed method provides optimized configurations of the FCHV model and the fuel cell stack, which has the capability in satisfying drive power request while satisfying vehicle driving schedule and battery state of charge (SOC) recovery with lower fuel consumption.     

商用车辆传动系统的概念——变速器对燃油消耗、噪声和舒适性的影响

车辆传动系统中的变速器对燃油消耗、噪声和舒适性都有明显的影响。这里以一些ZF公司的产品为例给出各种变速器在典型车辆中的应用。目前变速器的功率／重量比和以前产品相比在各方面都有明显的改善。而改善噪声水平和对舒适性方面的要求已变得非常重要，因此全自动变速器将赢得很大一块市场。在将来，适用于城市公共汽车的轮边电力驱动等新型传动系统将扩大传动系统的范围。     

后驱串联混动HEV乘用车整车性能仿真研究

《节能与新能源汽车路线图2.0》发布,国家鼓励节能车大力发展。串联混动HEV具有油耗低、结构简单等优点。本文以公司开发的某后驱串联混动HEV样车为基础,对动力系统进行了参数选型,对WLTC工况下汽车的整车性能进行了仿真分析,并与燃油版进行了对比。结果表明:该串联混动HEV动力系统参数选型合理,满足设定的整车性能目标,与燃油版车型的对比中油耗优势明显。     

Study on operating characteristics of fuel cell powered electric vehicle with different air feeding systems

In this paper the modeling of a fuel cell powered electric vehicle is presented. The fuel cell system consisting of a proton exchange membrane (PEM) fuel cell stack and balance of plant (BOP) was co-simulated with a commercial vehicle simulation program. The simulation program calculates the load of the fuel cell depending on the driving mode of the vehicle and also calculates the overall efficiency and each parasitic loss by applying the load in the fuel cell model that is used to estimate the performance of the entire vehicle system by calculating the acceleration performances and fuel economy of the vehicle. Two types of air feeding systems (blower type and compressor type) were modeled by using MATLAB/Simulink environment and the effect of fuel cell stack size (number of cells, cell area) on the fuel economy and performance of the fuel cell powered vehicle was investigated. Using a driving cycle of FTP-75, the required power, BOP component power loss, and system efficiency for two types of fuel cell systems were analyzed. Through this study, we could get a basic insight into the fuel cell powered electric vehicle and its characteristics.