Real-Time Co-optimization of Gear Shifting and Engine Torque for Predictive Cruise Control of Heavy-Duty Trucks

Fuel consumption is one of the main concerns for heavy-duty trucks.Predictive cruise control(PCC)provides an intriguing opportunity to reduce fuel consumption by using the upcoming road information.In this study,a real-time implementable PCC,which simultaneously optimizes engine torque and gear shifting,is proposed for heavy-duty trucks.To minimize fuel consumption,the problem of the PCC is formulated as a nonlinear model predictive control(MPC),in which the upcoming road elevation information is used.Finding the solution of the nonlinear MPC is time consuming;thus,a real-time implementable solver is developed based on Pontryagin’s maximum principle and indirect shooting method.Dynamic programming(DP)algorithm,as a global optimization algorithm,is used as a performance benchmark for the proposed solver.Simulation,hardware-in-the-loop and real-truck experiments are conducted to verify the performance of the proposed controller.The results demonstrate that the MPC-based solution performs nearly as well as the DP-based solution,with less than 1%deviation for testing roads.Moreover,the proposed co-optimization controller is implementable in a real-truck,and the proposed MPC-based PCC algorithm achieves a fuel-saving rate of 7.9%without compromising the truck’s travel time.

A human-sensitive frequency band vibration isolator for heavy-duty truck seats

In this study,a human-sensitive frequency band vibration isolator(HFBVI)with quasi-zero stiffness(QZS)characteristics for heavy-duty truck seats is designed to improve the comfort of heavy-duty truck drivers on uneven roads.First,the analytical expressions for the force and displacement of the HFBVI are derived with the Lagrange equation and d'Alembert's principle,and are validated through the prototype restoring force testing.Second,the harmonic balance method(HBM)is used to obtain the dynamic responses under harmonic excitation,and further the influence of pre-stretching on the dynamic characteristics and transmissibility is discussed.Finally,the experimental prototype of the HFBVI is fabricated,and vibration experiments are conducted under harmonic excitation to verify the vibration isolation performance(VIP)of the proposed vibration isolator.The experimental results indicate that the HFBVI can effectively suppress the frequency band(4-8 Hz)to which the human body is sensitive to vertical vibration.In addition,under real random road spectrum excitation,the HFBVI can achieve low-frequency vibration isolation close to 2 Hz,providing new prospects for ensuring the health of heavy-duty truck drivers.

Quantifying the Impact of In-Cab Alerts on Truck Speed Reductions in Ohio

In-cab alerts warn commercial vehicle drivers of upcoming roadway incidents, slowdowns and work zone construction activities. This paper reports on a study evaluating the driver response to in-cab alerts in Ohio. Driver response was evaluated by measuring the statistical trends of vehicle speeds after the in-cab alerts were received. Vehicle speeds pre and post in-cab alert were collected over a 47 day period in the fall of 2023 for trucks traveling on interstate roadways in Ohio. Results show that approximately 22% of drivers receiving Dangerous Slowdown alerts had reduced their speeds by at least 5 mph 30 seconds after receiving such an alert. Segmenting this analysis by speed found that of vehicles traveling at or above 70 mph at the time of alerting, 26% reduced speeds by at least 5 mph. These speed reductions suggest drivers taking actional measures after receiving alerts. Future studies will involve further analysis on the impact of the types of alerts shown, roadway characteristics and overall traffic conditions on truck speeds passing through work zones.

Active Noise Control of the Heavy Truck Interior Cab

In order to control the noise of the heavy truck interior cab effectively, the active noise control methods are employed. First, an interior noise field test for the heavy truck is performed, and frequencies of interior noise of this vehicle are analyzed. According to the spectrum analysis of acquired noise signal, it is found out that the main frequencies of interior noise are less than 800Hz. Then the least squares lattice （LSL） algorithm is used as signal processing algorithm of the controller and a closed-loop control DSP system, based on TMS 320VC5416, is developed. The residual signal at driver＇s ear is used as feedback signal. Lastly, the developed ANC system is loaded into the heavy truck cab, and controlling the noise at driver＇ s ear for that truck at different driving speeds is attempted. The noise control test results indicate that the cab interior noise is reduced averagely by 0.9 dBA at different driving speeds.

Truck Cab Design： Perceptions of Women Truck Drivers

The trucking industry is a major force behind the United States （US） economy with approximately 750,000 interstate motor carriers. Trucks deliver 70% of all freight tonnage while 80% of U.S. communities receive goods exclusively by truck. The motor carrier industry provides jobs, generating significant income and tax revenue, representing approximately 5% of U.S. GDP （gross domestic product）. Despite one of every 13 people employed in a trucking-related job, there is a significant driver shortage. The ATA （American Trucking Associations） currently projects a shortage of 20,000 to 25,000 drivers in the for-hire truckload market. Women are well positioned to address this shortage. In 2011, women represented 7% of total employment in the U.S. trucking industry. The purpose of this study was to identify truck design needs for women truck drivers. This research is significant due to limited data sources about truck design needs for women drivers. This study also contributes to the body of knowledge about women in the trucking industry. In response, a 33-question survey was developed using QualtricsTM survey software. In April, 2012, an electronic survey was distributed to 663 Women in Trucking Association members over a two-week period with a response rate of 18%. Results were separated into quantitative and qualitative data and analyzed accordingly. Adjustability was a central issue facing women truck drivers. Recommendations for seat design, side mirrors, steps, handrails, hydraulic hood lifters, and steering consoles will be presented. Limitations of the study and recommendations for future research will be discussed.

基于《汽车正面碰撞的乘员保护》的某轻卡碰撞CAE模型对标探索与实践

文章旨在探讨基于《汽车正面碰撞的乘员保护》的某轻卡碰撞CAE模型的建立与修正。通过对该标准的详细解读和分析,结合实际案例,本研究建立了一套适用于某轻卡碰撞仿真的整车CAE模型及分析方法。经整车实物碰撞验证和比对,B柱加速度曲线相似度高达96.5%,加速度曲线峰值时刻基本吻合、试验峰值优于CAE峰值20g,驾驶室门框变形量差异小于20mm,证明该CAE模型在预测碰撞情况和评估车辆安全性能方面具有较高的准确性和可靠性。本研究的成果为轻卡碰撞仿真提供了一种新的方法和视角,对于提升轻卡碰撞安全性能具有重要指导意义和实践价值。

基于柔性光伏组件的重型卡车驾驶室供能系统的实验研究

中国重型卡车保有量大,驾驶员工作强度极大,驾驶室内空间有限且封闭,提高驾驶员的热舒适性对于缓解其疲劳、提高行车安全性具有重要意义。为在提高驾驶员热舒适性的同时减少重型卡车的能源消耗,研发了一套基于柔性光伏组件的重型卡车驾驶室供能系统,以国产重型卡车中销量最高的车型为例搭建了重型卡车驾驶室实物模型,对使用柔性光伏组件供电和半导体制冷装置实现驾驶室局部温度控制和充放电技术集成的应用方法进行了探索,并通过实验从局部温度控制策略、光伏发电与变负载充电关系这两个方面对本供能系统设计的合理性进行了验证。研究结果表明:以长沙地区为例,经计算,重型卡车(平稳运行时)驾驶室内的夏季制冷总负荷为3995 W,使用6组(共18片)半导体制冷片组即可达到驾驶室局部的制冷效果。使用人工环境箱模拟长沙地区夏季、冬季环境温度进行局部温度控制效果实验,本供能系统的制冷和供暖效果均可满足人体的热舒适性需求,验证了所提出局部温度控制策略的可行性。根据光伏发电与变负载充电实验,1块XZL-A100型单晶硅柔性光伏组件的年发电量约为13.3 kWh,本供能系统的光伏发电模块采用6块单晶硅柔性光伏组件并联,发电量可以满足重型卡车驾驶室局部温度控制的用电需求。

基于仿真和试验的轻卡驾驶室前保险杠疲劳性能研究

文章使用有限元分析和试验相结合的方法对某款轻卡驾驶室前保险杠的疲劳性能展开研究。首先,建立前保险杠的有限元模型,将强度计算结果和台架应力测试结果进行对比,校准了有限元模型,为疲劳性能分析奠定了基础;其次,进行疲劳仿真分析和疲劳试验,两者结果基本吻合,都指向原结构中存在应力集中,疲劳性能不能满足设计和使用要求;最后,对原前保险杠结构进行优化设计,去除应力集中区域,并对优化的结构进行疲劳性能仿真,相比原方案,优化方案的疲劳性能有了大幅的提升,最终优化方案顺利通过了台架试验和可靠性道路试验,并投放使用。仿真和试验相结合的方法为开展轻卡前保险杠的疲劳性能研究提供了非常有效的手段。

重卡驾驶室液压翻转机构性能参数的优化分析

重卡驾驶室液压翻转机构的性能是衡量整车性能的重要组成部分。为提升翻转机构的性能,建立翻转机构的数学模型,以顶出力系数、油压波动系数、翻转容量3个参数作为翻转机构的性能评价指标,将翻转机构的性能优化问题转化成有约束的多目标优化问题。采用线性加权法的评价函数对有约束的多目标问题进行优化,利用层次分析法(AHP)确定各项性能评价指标的加权系数,设置约束条件后对优化结果进行求解。针对某型重卡驾驶室翻转机构进行实例的优化分析,在MATLAB中对系统模型进行优化和求解,最后搭建AMESim模型进行仿真验证。结果表明:对加权系数的确定而言,AHP是一个稳定和有效的方法,且优化分析结果显示翻转机构的性能相比优化前提升了11.72%,与仿真结果近似。

驾驶室翻转电机继电器故障分析及优化验证

针对某重卡车型驾驶室翻转系统中的翻转电机故障率较高,继电器易损坏的问题,通过电路工作原理分析、故障再现、试验验证,发现问题产生的根本原因为电机在启动或断开瞬间产生反向电压,造成继电器触点拉弧烧蚀。通过对电路原理进行分析改进,增加保护二极管,实现对电机反向电压的抑制,并进行试验及实车验证,解决了继电器烧蚀问题,降低翻转电机故障率,提升产品可靠性。

某重型卡车车身侧面泥水飞溅污染的研究与控制

针对某重型卡车车身侧面泥水飞溅污染的问题,建立其空气动力学仿真模型,采用外流场耦合液相的方法开展了仿真分析。根据原车的污染情况及流场特点提出了优化包角板扰流结构、增加轮眉及优化前保结构三个优化方案。仿真结果表明:三个优化方案均能有效的改善驾驶室侧面污染。并对优化方案进行了试验验证,增加轮眉方案可有效的改善驾驶室侧面及关键的门把手区域的污染。本研究为该车型防污性能的提升及新车型的开发提供了重要参考。

基于形态仿生学的厢式货车复合气动减阻方案

为降低某厢式货车的气动阻力,基于形态仿生,设计了仿生导流罩、仿生驾驶室和仿生货厢3种新型气动减阻方案和1种复合仿生减阻方案。先研究了3种单一仿生减阻方案对气动阻力因数的影响效果及其减阻机理。后将3种单一减阻方式结合在一起,探究了复合仿生减阻方案的减阻效果。结果表明:相对于货车原始模型,仿生导流罩模型、仿生驾驶室模型和仿生货厢模型的最优减阻率分别为3.57%、9.45%和11.86%。复合减阻方案的气动阻力因数减小率是24.5%,减阻效果明显。因而,基于形态仿生学设计的厢式货车减阻结构,改善了厢式货车周围的流场结构,降低了气动阻力。

特定车速下轻型卡车驾驶室异常抖动故障诊断方法

常规驾驶室异常抖动故障诊断方法多采用神经网络算法,忽略了故障数据之间的关联性,使得诊断准确率较低;提出特定车速下轻型卡车驾驶室异常抖动故障诊断方法;利用数据采集器采集驾驶室在线信息数据,并采用周期性的方式对数据分类,分析故障数据之间的内部关系,解析收集的信息数据,判断车辆驾驶室运行状态,并采用故障树方法计算底部事件的概率重要度,实现驾驶室抖动故障诊断;利用对比实验对所提方法的诊断性能进行测试,结果显示,所提方法对于驾驶室异常抖动故障具有较高的诊断准确率,最高值为97%。

矿用自卸车无A柱驾驶室翻车保护结构的设计

根据矿用自卸车的市场需求和现有技术水平,设计了矿用自卸车无A柱驾驶室翻车保护结构。翻车保护结构主体采用封闭圈梁结构,六根立柱分别与顶部和底部框架构成封闭的四边形和三角形圈梁,保证驾驶室整体强度。顶部左右纵梁外侧分别设置吸能结构,有效避免车辆侧翻时主体骨架变形过大侵入驾驶员体内。驾驶室下部支撑结构采用变截面悬臂梁结构,保证驾驶室的垂向承载能力。通过有限元仿真分析,初步验证翻车保护结构的可行性。通过对驾驶室进行翻车保护结构试验,确认满足标准规定的性能要求。

基于虚拟迭代技术的某纯电轻卡驾驶室疲劳寿命分析

针对车辆耐久试验中钣金及焊点开裂问题,通过采集道路试验随机载荷谱,基于虚拟迭代方法提取了某纯电轻卡车型驾驶室疲劳载荷。基于迭代载荷完成了驾驶室钣金及焊点疲劳寿命分析,有限元分析结果与实车路试一致,说明了该方法的有效性,并形成一套可操作的技术文件,为后续车型开发提供技术积累。针对存在的风险进行钣金及焊点优化,有效提升产品耐久性能。

基于AMESim的重卡驾驶室振荡优化分析

重卡驾驶室在回落过程的振荡严重影响了整个液压系统的使用寿命,造成了较大的安全隐患。为提高翻转机构的使用寿命、降低安全隐患,对振荡原因进行分析,从振荡的产生时间和幅度两个方面对其进行优化分析。通过改变翻转机构上下铰接点的位置减少振荡产生的时间。根据薄壁小孔数学模型近似替代液控单向阀,改变最大开度时的特征流量或者相应的压降,来间接改变液控单向阀控制阀口的大小,从而降低阀芯的开启速度,减小驾驶室振荡的幅度。在AMESim中搭建翻转系统模型,应用控制变量法对振荡的产生时间与幅度的优化结果进行仿真验证。结果表明,通过改变驾驶室翻转机构的部分参数,对振荡的产生时间与幅度有着不同程度的影响,为企业人员对振荡情况的优化工作提供了参考。

某轻型商用车驾驶室抖动问题优化

针对某轻型厢式卡车空载状态下,在40~60km/h车速区间内,驾驶室存在较明显的前后抖动现象。文章采用工作模态分析(OMA)试验方法,对模态频率、阻尼、振型等进行了分析,确定了驾驶室抖动峰值频率。在传递路径上确定了驾驶室悬置和悬架隔振存在较明显问题,结合问题点,制作对应的优化样件进行整改。从测试结果上看,效果明显,对实际工程问题的解决具有借鉴意义。

重卡驾驶室总布置设计方法与实践

文章主要介绍重卡驾驶室在总布置设计过程中的基本流程和方法,可以为工程师在重卡驾驶室总布置设计过程中涉及的主要内容提供一定的经验参考。其中包括了人机工程、白车身、仪表、座椅、外饰等关键硬点尺寸设计方法及参考指标,以及在总布置设计过程中要注意的关键内容。该文章对重卡驾驶室总布置设计都提供了基础的帮助。

重型商用车驾驶室轻量化设计

以某重型商用车驾驶室为研究对象,运用拓扑优化设计方法对该驾驶室进行轻量化分析与改进设计,并与原驾驶室的性能进行了对比。结果表明,轻量化驾驶室的结构强度、刚度和低频固有振动特性不低于原驾驶室,并使驾驶室抗前部摆锤冲击和高顶驾驶室耐顶压性能得到了改善。在不改变驾驶室结构材料特性的条件下,使驾驶室质量减小46 kg,取得了良好的轻量化效果。

驾驶室结构减振降噪的拓扑优化设计

针对驾驶室减振降噪,提出一种基于驾驶室声振耦合系统声学贡献度分析的结构优化方法。运用模态叠加法求解耦合系统在外界激励下的动力学响应,利用声学贡献度分析、评价并确定对驾驶员右耳声压贡献突出的板件,以贡献度最大面板区域为设计域、一阶固有频率最大化为目标函数对结构进行拓扑优化。结构优化改进后,耦合系统主要激振频率下驾驶员右耳位置峰值声压级降低29dB,表明在保持驾驶室结构重量相对不变的情况下运用该方法有效降低车内噪声。