基于hyperworks的前桥有限元分析

汽车前桥工字梁是汽车中的重要部件，应具有足够的强度和刚度。首先按照厂家所提供的AUTOCAD图纸在UG中建立桥壳几何模型，然后在Hyperworks软件中进行网络划分，并进行加载和约束，完成有限元计算分析。     

智能交通系统中的公交车辆动态调度研究

阐述公交车辆静态调度的局限性，据此提出公交车辆动态调度策略及其在线调整方法，并分析研究运营车辆出现意外事故，故障及延误等实际,财度管理人员应如何采取相尖的应急调度措施和方案。实验分析结果表明，实施公交车辆动态调度策略。可有效地解决公交车辆的静态调度不足，达到公交车辆指标调度自动化，以提高公交车辆的运营效率和服务质量，为公交车辆智能调度提供切实可行的调度方法。     

公交与右转混合型专用道仿真分析及效益评价

为解决设置公交专用道所带来的道路资源利用率低，相邻车道交通压力增大，专用道分时段开启致使社会车辆行驶混乱等问题，基于车种分离思想，提出一种公交车辆与右转车辆混合专用道的组织方式，允许公交车辆与右转社会车辆共用一条车道，以寻求保持公交优先与减少对社会车辆影响的平衡点。为论证该方案的可行性，首先，针对所研究的道路环境，提出了基于流量生成模型与配时优化模型的车道组仿真流程；随后，在考虑红灯时右转车辆行驶特性的前提下，建立了人均延误和车均延误的双指标评价矩阵模型；最后，分别在MATLAB和VISSIM仿真平台上，实现了对传统车道组、公交与右转混合型专用道车道组和公交专用道车道组3种方案的效益评价，并对其中的关键影响因素进行分析。仿真结果表明：所提出的公交与右转混合型专用道车道组的总体车均延误与人均延误在大多情况下处于较低水平，而公交专用道车道组和普通车道组也具有各自的优势区域；公交与右转混合型专用道的车道组织方式可以在保证社会车辆延误不明显增加的情况下，有效确保公交车辆的优先性，在一定条件下具有适用性，在工程实践中可作为公交专用道的过渡或替代方案。     

双前桥线控转向系统的应用研究

线控转向是一种先进的转向技术。文中介绍了线控转向系统的结构、工作原理及特点,以及线控转向技术在双前桥车辆领域的研究热点。展望了线控转向技术在双前桥车辆领域的应用前景。     

西安市公交车辆市场分析

针对几年西安市交车辆市场的状况，结合中国城市客车制造行业的生产情况，分析影响西安市公交车辆市场的主要因素和公交车辆类型向多样化发展的趋势，探讨西安市公交车辆市场的发展。     

公交车辆行程时间预测方法研究

章以智能交通运输系统为背景，分析公闪车辆的行驶特性，在大量实测数据的基础上，应用统计回归理论，进行了公交车辆行程时间预测模型的假设和建立，并给出了公交车辆行程时间的预测结果。     

双前桥载货汽车第二前桥内轮转角优化设计

理论分析双前桥载货汽车第一前桥总成、第二前桥总成转向关系,确定双前桥内轮转角的总传动比的定义,然后计算各转向角理论状态下的总传动比,与车辆转向系统设计的总传动比进行比对,明确在各转向状态下的最优传动比。达到在任一转向状态下,第一前桥、第二前桥可最大限度绕同一旋转中心协调转向,避免了前桥总成拖磨吃胎,降低了油耗。     

浅谈东风双前桥重型商用车侧滑及调整的方法

双前桥重型商用车侧滑调整不当所带来的侧滑不合格等问题会极大地降低车辆检测下线的通过率、增加下线车辆的调试难度并加剧轮胎磨损,影响车辆性能,从而产生巨大损失。为此,笔者介绍了双前桥重型商用车侧滑及调整的方法,以及在提高该类车型侧滑一次通过率方面的应用情况。     

重庆市公共汽车的腐蚀现状

重庆地处中国西南，气候闷热，空气湿度大，又是酸雨多发地区，对各类运行车辆的环境腐蚀严重。本文对重庆市公交和电车公司的使用车辆在这种典型环境下的腐蚀情况和由于腐蚀所造成的车辆的运行损失及腐蚀对公交车辆形貌的影响进行系统调查研究。结果表明，环境腐蚀不仅严重影响了重庆公交公司运行车辆的形象、运行的安全性，而且给公交公司造成了重大经济损失，影响了公交公司的利润。上述调研结果及进一步对腐蚀产物的分析将为公交车辆防腐抗力的改进提供依据。     

实施科技创新，提高车辆安全品质

为确保公交车辆安全运行，预防各类事故发生，杭州公交集团始终坚持“预防为主，安全第一”的方针，始终坚持“科学配置，品质第一”的宗旨，紧紧围绕车辆运营安全，积极探索公交车辆安全运行管理新路子和新办法，在车辆技术配置、应用手段和管理办法等方面做了大量的工作。     

多轴移动荷载下沥青路面的动态响应特性

为分析多轴移动荷载下沥青路面的动态响应特性,通过现场调查建立了不同轴型作用下沥青路面的三维有限元模型,分别研究了单后轴、双后轴及三后轴轴载均匀分布、三后轴车轴载不均匀分布及三后轴车前轴悬空条件下对路面的影响。结果表明:多轴车轴距大于3 m时,各轴对路面的作用相互独立,轴数的增加对路面竖向位移产生叠加作用,对路表最大剪应力及压应力影响不明显;三后轴车中轴对路面竖向位移作用最大,较前轴及后轴分别增大23.7%和18.2%,中轴及后轴对路表剪应力有一定影响,而各轴对路表最大压应力基本没有影响。研究结果显示多轴车轴载不均匀分布对路面破坏会产生较大影响。     

商用车双转向桥中间杆系优化设计

商用车双转向桥包含两个独立的转向梯形机构,它们之间的运动是通过中间杆系来传递的.在设计双转向桥转向系统时,为了避免转向桥轮胎异常磨损,需要两个转向桥的车轮转角协调变化.提出了一种对现有双转向桥中间杆系优化设计的方法,可协调车辆第一、第二转向桥的转角关系,避免了横向滑移导致的双前桥车轮转向时造成的轮胎异常磨损.     

Robust road friction estimation during vehicle steering

Automated vehicles require information on the current road condition, i.e. the tyre–road friction coefficient for trajectory planning, braking or steering interventions. In this work, we propose a framework to estimate the road friction coefficient with stability and robustness guarantee using total aligning torque in vehicle front axle during steering. We first adopt a novel strategy to estimate the front axle lateral force which performs better than the classical unknown input observer. Then, combined with an indirect measurement based on estimated total aligning torque and front axle lateral force, a non-linear adaptive observer is designed to estimate road friction coefficient with stability guarantee. To increase the robustness of the estimation result, criteria are proposed to decide when to update the estimated road conditions. Simulations and experiments under various road conditions validate the proposed framework and demonstrate its advantage in stability by comparing it with the method utilising the wide-spread Extended Kalman Filter.     

汽车前轴垂直载荷谱变化规律的研究

通过大量试验和统计,得出了在良好、较差柏油路面条件下,载货汽车前轴垂直动态载荷幅值、均值、最大值随行驶车速和前轴静态轴荷的变化规律。前轴垂直动态载荷最大值主要受前轴静态轴荷的影响,与前轴静态轴荷成线性关系,并且90%概率下与前轴静态轴荷的比例不超过1.4。     

Experimental investigations on continuous regenerative anti-lock braking system of full electric vehicle

Functions of anti-lock braking for full electric vehicles (EV) with individually controlled wheel drive can be realized through conventional brake system actuating friction brakes and regenerative brake system actuating electric motors. To analyze advantages and limitations of both variants of anti-lock braking systems (ABS), the presented study introduces results of experimental investigations obtained from proving ground tests of all-wheel drive EV. The brake performance is assessed for three different configurations: hydraulic ABS; regenerative ABS only on the front axle; blended hydraulic and regenerative ABS on the front axle and hydraulic ABS on the rear axle. The hydraulic ABS is based on a rule-based controller, and the continuous regenerative ABS uses the gain-scheduled proportional-integral direct slip control with feedforward and feedback control parts. The results of tests on low-friction road surface demonstrated that all the ABS configurations guarantee considerable reduction of the brake distance compared to the vehicle without ABS. In addition, braking manoeuvres with the regenerative ABS are characterized by accurate tracking of the reference wheel slip that results in less oscillatory time profile of the vehicle deceleration and, as consequence, in better driving comfort. The results of the presented experimental investigations can be used in the process of selection of ABS architecture for upcoming generations of full electric vehicles with individual wheel drive.     

实现轿车底盘关键结构部件同步开发的核心标准研究

从满足整车高性能要求的角度出发,探讨核心标准与同步开发的关系,深入分析轿车前副车架及后桥等底盘关键结构部件核心标准的行业现状,提出标准制定的两大技术路线,为底盘关键结构部件实现同步开发奠定基础。     

Kinematic and dynamic analysis of a heavy truck with individual front suspension

The main focus of this work is on the characteristics of a commercial vehicle with individual front suspension (IFS). Both kinematic and dynamic properties of the vehicle are investigated through simulations and analytical expressions. Moreover, employing the model of the tractor semitrailer combination, the study presents the results of comparison between the trucks with IFS and rigid front axle with respect to comfort and handling. This is done by analysing the responses of the vehicles to different road and steering inputs. The obtained results show enhanced comfort and steering feeling for the truck with IFS.     

8×4重型自卸车制动性能分析

以某8×4重型自卸车为分析对象,建立了四轴汽车的制动力学模型,对该车在满载、超载情况下进行各轴载荷的计算,前、中、后桥制动力矩和制动力分配分析,在此基础上,提出了多轴汽车的行车制动性能分析方法,并与该车制动性能O型试验结果数据进行对比。实例分析结果表明,该方法简单、实用,能对四轴汽车行车制动性能进行有效分析。     

某前驱动桥断裂失效分析

对某驱动前桥断裂进行了多角度系统分析,探讨了半轴套管材质、热处理过程控制和桥壳塞焊工艺对前桥疲劳寿命的影响,试验及分析表明：热处理过程对套管的冲击功有较大影响,桥壳塞焊孔的加工定位误差易引起塞焊孔处应力变化甚至增加应力集中,通过重新制定套管热处理工艺,优化桥壳塞焊孔位置,缓解了最大拉应力区域的应力叠加效应,上述措施有效改善了某桥管韧性,目前该类型驱动前桥运行正常。     

Independent Suspension, Self Steered Axle, and 4WS for Busses

The dynamic behavior of commercial vehicles fitted with differentr types of suspension mechanisms and steering devices is investigated in this paper. Six vehicle models have been constructed: 2WS-SA is a standard two wheel steering bus with solid axles; 2WS-DW is a 2WSA vehicle with independent double wishbone suspension in front and rear axles; SSA-SA is a 2WS system with solid axles, the rear one being mounted on a self steered mechanism; SSA-DW is a vehicle with independent double wishbone suspension in the front axle, and a solid self steered rear axle; 4WS-SA has four wheel steering with solid axles; and 4WS-DW is a 4WS vehicle with independent double wishbone suspension in front and rear axles. The dynamic response of these models has been assessed in terms of lateral acceleration, yaw velocity, tire forces, tire force reserves, and slip angles. The expected advantages of a 4WS system (higher acceleration rates and lower slip angles) will be corroborated but, at the same time, it will be shown that they are obtained at the cost of lower force reserves. Self steered mechanisms produce smaller body slip angles, but it will be shown that they give rise to larger yaw velocity overshootings. The particular independent suspension analyzed does not show significant improvements with respect to the solid axle counterpart.