基于摄动理论的汽车二维碰撞模型抗干扰性分析

目前国内外的汽车事故再现模型主要基于动量定理来分析的.通过对典型的汽车二维非对心点碰撞模型分析求解计算,并且基于摄动理论,应用数学方法分析模型的抗干扰能力.通过理论分析,提高模型计算的准确性和可靠性.     

短连线交叉口群通行能力计算方法研究

针对短连线交叉口群的通行能力计算提出了相应的理论和方法。文章首先从不同角度对短连线交叉口群进行了界定，然后利用波动理论和车流运行的时空图，建立了短连线通行能力和损失的通行能力计算模型，并采用数学方法建立了通行能力及其损失量随着各个影响因素变化的图表。从中得出了一些重要的结论，且在信号协调控制方面提出了一些建议。     

高速公路软基处理技术的模糊综合评价

软土地基处理技术评价是一个既含有定量因素,又包括定性因素的问题,运用传统的数学方法来建立评价模型是比较困难的。该文利用模糊理论对非定量问题进行分析,从而将复杂的技术评价问题简单化、直观化,建立了多层次综合模糊评价模型,对津滨高速公路的软基处理技术分别进行了模糊综合评价。     

软土路基的过程化设计和沉降变化趋势面的最小二乘拟合

提出了软土路基设计为过程化设计的概念，在此基础，采用最小二乘拟合数学方法，建立软土路基沉降变化趋势面实用模型的过程和方法，并给出实例，为进一步运用时间序列分析方法定量研究沉降趋势，实现工后沉降量的精确预测和控制模型的建立，以及在计算机上实现三维量化分析奠定基础。     

发动机图像数据提取

对获得的发动机万有特性图像编写程序实现数据提取,同时对已获得的图像数据,采用数学方法建立发动机模型．通过误差分析与图像对比．表明建模方法的正确。     

应用于车辆实时动力学仿真的悬架模型

针对车辆动力学实时仿真的要求提出一种新的悬架建模方法。将悬架系统视为车身与车轮之间的无质量复合约束，利用悬架杆系的多体运动学模型和准动力学模型来分析悬架系统的运动和力学传动特性，从而悬架动力学问题简化为代数方程组的求解。与基于侧倾／力矩中心理论建立的等交悬架模型相比，该方法可分析悬架杆系内部作用力，并能更准确地描述悬架在水平方向的约束作用；与应用传统多体动力学理论建立的模型相比，该方法解决了仿真实时性的问题。基于这种方法建立了国产某轿车麦弗逊式悬架模型，并将仿真结果和道路试验及ADAMS仿真结果进行了对比，有较好的一致性。     

混凝土拱桥既有墩台再利用方案判定模型建立研究

为解决混凝土拱桥既有墩台的再利用问题，采用基于粗糙集理论构建判定模型的方法对既有墩台再利用方案决策进行研究。结果表明：1)粗糙集理论能够简化指标体系，筛选出切合实际工程的判定指标；2)利用粗糙集理论中的属性依赖度计算，可对指标进行赋权，无需再借助其它理论方法就能计算指标权重；3)运用方案判定模型，能得到科学合理的决策结果。将基于粗糙集理论建立的混凝土拱桥既有墩台再利用判定模型应用于贵州花鱼洞大桥既有桥台再利用的方案决策中，成功验证了方案判定模型的可行性。     

铅酸蓄电池放电特性研究

电动汽车具有低污染、低排放、低能耗、低噪声、高效率等优点,在环境保护和新能源利用等方面具有无可比拟的优势,是解决能源危机和环境污染问题较为有效的途径。蓄电池作为电动汽车的动力源,直接影响着电动汽车的动力性和经济性,因此本文针对应用最普遍、技术最成熟的铅酸蓄电池放电特性进行研究。本文首先对铅酸蓄电池的放电原理进行研究,建立了铅酸蓄电池放电模型,基于蓄电池综合测试系统进行了不同放电倍率下的放电试验,最后应用归一化数学方法建立了蓄电池放电试验模型,获得了蓄电池端电压与SOC的关系曲线,为蓄电池的进一步研究奠定了试验基础和理论模型。     

山区一级公路升级改造工程施工招标评标方法探索与研究

介绍评标方法国内外研究现状。运用效用理论,分析得出山区一级公路升级改造工程施工招标较好的评标方法是综合评标法及基于综合评标法的双信封评标法,并建立了综合评标模型。最后,对评标模型进行了实证分析。     

BT模式下的桥梁工程项目风险模糊综合评价

以某BT市政桥梁工程项目风险管理的目标为出发点,结合BT项目及市政工程项目风险管理的特点,通过数学方法建立了项目风险模糊综合评价的指标体系;构建了BT市政工程项目风险管理评价指标及模型,并根据模糊评价理论的基本原理对工程风险进行定量分析。     

On Lateral Dynamics of Vehicles Based on Nonlinear Characteristics of Tires

The problems of vehicle lateral dynamics based on nonlinear characteristics of tires are discussed in this paper. A new nonlinear perturbation model on the cornering behavior of the tire is constructed. The nonlinear influences of tires on the steady-state steering behavior, dynamic response and handling stability of vehicle are discussed, applying the approximate analytical methods for nonlinear vibration. An analytical criterion of stability is obtained. Some numerical examples are given.     

On Lateral Dynamics of Vehicles Based on Nonlinear Characteristics of Tires

The problems of vehicle lateral dynamics based on nonlinear characteristics of tires are discussed in this paper. A new nonlinear perturbation model on the cornering behavior of the tire is constructed. The nonlinear influences of tires on the steady-state steering behavior, dynamic response and handling stability of vehicle are discussed, applying the approximate analytical methods for nonlinear vibration. An analytical criterion of stability is obtained. Some numerical examples are given.     

A comparative study on fault detection methods of rail vehicle suspension systems based on acceleration measurements

Reliability of the railway vehicle suspension system is of critical importance to the safety of the vehicle. On-line health condition monitoring for the suspension system of rail vehicles offers a number of benefits such as preventing further deterioration of vehicle performance, enhancing vehicle safety, increasing operational reliability and availability, and reducing maintenance costs. It is desirable to timely detect the fault and monitor the performance degradation of vehicle suspension systems. In this paper, a comparative study on fault detection methods of urban rail vehicle suspension systems is considered. A novel sensor configuration is proposed where the underlying vehicle system is equipped with only acceleration sensors in the four corners of the carbody, the leading and trailing bogie, respectively. A mathematical model is developed for the considered vehicle suspension system. Both model-based and data-driven approaches are studied for the suspension fault detection problem. The robust observer, the Kalman filter combined with the generalised likelihood ratio test method, the dynamical principle components analysis and the canonical variate analysis approaches are applied to the fault detection problem. The simulation is carried out by means of the professional multi-body simulation tool, SIMPACK. In addition, the advantages and disadvantages of these methods are compared. The simulation results show that the data-driven methods outperform the model-based methods.     

Relationship between occupant injury and the perturbation mark on the velocity indicator on a cluster panel

A perturbation mark is occasionally produced on the velocity indicator of the cluster panel of a vehicle during a vehicle collision. This mark can be used to estimate the velocity of the vehicle at the moment of the vehicle’s impact. In this study, the effect of the impact velocity and the deceleration of the vehicle on the perturbation mark were investigated, and an analysis of the driver’s injury was also conducted through a numerical pulse representation and computer simulations. Sled and pendulum tests were used to replicate the conditions that produce a perturbation mark on the velocity indicator of a cluster panel. It was verified that a higher peak acceleration is more likely than the impact velocity to cause a perturbation mark. According to the computer simulation results, a driver’s injury could be more severe at higher peak accelerations with a constant impact velocity. If a perturbation mark, which can be used to estimate the impact velocity, is found while investigating a vehicle accident, this mark reveals that the acceleration was higher than that listed in the related crash report. Therefore, the injuries of the occupants could be more serious than those expected at the reported impact velocity.     

Driver models in automobile dynamics application

Understanding the driver of an automobile has been attractive to researchers from many different disciplines for more than half a century. On the basis of their acquirements, models of the (human) driver have been developed to better understand, analyse and improve the combined couple of driver and automobile. Due to distinctive demands on the models in accordance with different kinds of applications, a variety of driver models is available. An overview of driver models is given with respect to their application and different methodical modelling approaches. The emphasis is put on the interest of engineers, who generally focus on the automobile (like design and optimization of vehicle components and the overall vehicle dynamics behaviour) by applying their approved (mathematical) methods. Nonetheless, a brief look beyond is added to better complete the view on the involved task of driving and driver modelling for automobile dynamics application.     

Dynamical Analysis of a Simple Vehicle on a Periodic Guideway

The dominant vertical motions of a simple vehicle traveling on a flexible periodic guideway is investigated. The mathematical model leads to a state equation with periodic coefficients and periodically jumping states. The aim of the paper is the dynamic analysis of the vehicle-guideway system with respect to stability, guideway deflections and vehicle accelerations. As alternative to the common simulation technique, the analytical solution based on Floquet theory is applied. Both methods are implemented in a computer program and used to perform a detailed parameter study which shows the dependence of the dynamical system behavior on the nondimensional system parameters.     

On fault isolation for rail vehicle suspension systems

Reliability of the railway vehicle suspension system is of critical importance to the safety of the vehicle. It is very desirable to monitor the health condition and the performance degradation of the suspension system online, which offers the important information of the suspension system and is critically important for the condition-based maintenance rather than scheduled maintenance in the future. Advanced fault diagnosis method is one of the most effective means for the health monitoring of the suspension system. In this paper, taking the lateral suspension system as an examcple, the fault isolation issue for different component faults occurring in the suspension system is concerned. The sensor configuration for obtaining the vehicle state information and the mathematical model for the lateral suspension system are presented. Four fault features in the time domain and three fault features in the frequency domain are used for each sensor signal. Three different methods, Dempster–Shafer (D–S) evidence theory, Fisher discrimination analysis (FDA) and support vector machine (SVM) techniques are applied to the fault isolation problem. Simulation study is carried out by means of the professional multi-body simulation tool, SIMPACK. The simulation results show that these methods can isolate the considered component faults effectively with a high accuracy. The D–S evidence-based fault isolation approach outperforms the other two methods.     

预瞄驾驶员模型中车辆操控稳定性的分析

通过将驾驶员模型、汽车运动学模型与闭环控制系统相结合,给出了一种基于最大预瞄距离驾驶员模型的空间方程.采用Lyapunov-Krasovskii泛函方法,分析基于该模型的“人—车—路”闭环控制系统的指数稳定性条件.利用所建立的4轮车辆驾驶员模型,分别采用不同的最大预瞄距离值和驾驶员反应时滞值,对车辆路径跟随进行了仿真试...     

经济目标下车辆最佳维护周期的研究

车辆最佳维护周期可提高车辆的技术状况,保证行车安全,减少维修费用。利用更新理论和更新函数,基于费用最低这一优化目标,建立车辆最佳维护周期数学模型,选取大众速腾1.6 L样本车相关数据,对模型进行求解,确定出车辆的最佳维护周期。结果显示选取的样本车,在维护周期为8 582 km时,其单位行驶里程维护费用最低;并利用样本车对模型的有效性进行了验证,运行试验表明该数学模型,有效、可靠,可完全用于指导实际车辆的维护保养工作。