The dynamics of Charles Taylor’s remarkable one-wheeled vehicle

In the 1950s and 1960s, Charles F. Taylor designed and tested various prototype one-wheeled vehicles. These machines were stabilized and steered using gyroscopes. In this paper, a simple model of a one-wheeled vehicle is presented and analyzed. This analysis explains the ability of these machines to exhibit stable steady motions.      

Stochastic single vehicle routing with a predefined customer sequence and multiple depot returns

We study the routing of a single vehicle that delivers multiple products under stochastic demand. Specifically, we investigate two practical variations of this problem: (i) The case in which each product type is stored in its dedicated compartment in the vehicle, and (ii) the case in which all products are stored together in the vehicle’s single compartment. Suitable dynamic programming algorithms are proposed to determine the minimum expected (routing) cost for each case. Furthermore, the optimal routing policy is derived by developing appropriate theorems. The efficiency of the algorithms is studied by solving large problem sets.     

多车场有时间窗的多车型车辆调度及其禁忌算法研究

本文针对物流配送中的多车场车辆调度问题提出了两种多车场的处理方法，介绍了多车场车辆调度问题中容量、时间窗、多车型等多种约束的处理方法，并且根据具体约束情况设计了禁忌算法，对多车场有时间窗的多车型车辆调度问题加以实现，给出了一个具有代表性的算例试验结果和结果分析，通过试验表明了此方法对优化有时间窗的多车型车辆调度问题的有效性．     

车辆路径问题的改进遗传算法

提出一种基于遗传算法的求解车辆路径问题的新算法,避免传统遗传算法处理不可行约束条件中惩罚项系数选取不当所出现的问题.同时,通过现实例子分析该算法的优劣性,实验结果表明该算法是一种有效的算法.     

Stability and Oscillations in a Time-Delayed Vehicle System with Driver Control

In this paper, linear stability and chaotic motion of a time-delayednonlinear vehicle system are studied. The stability is determined bycomputing the spectrum associated with a system of linear retardedfunctional differential equations, which reveals that a loss ofstability occurs following a Hopf bifurcation. Beyond the critical valuefor linear stability, the system exhibits limit cycle motions.Subharmonic, quasi-periodic and chaotic motions are observed for asystem excited by a periodic disturbance.     

汽车碰撞砼护拦过程的数值模拟

将汽车与砼护拦简化为刚体，给出了描述碰撞过程中车辆三维空间运动的Ｅｕｌｅｒ－Ｌａｇｒａｎｇｅ方程－微分代数方程组，采用半显式外插方法求解上述方程组。数值计算得出的车辆各方向上的最大平均加速度、最大侧倾角、最大俯仰角、车轮沿护拦面的最大爬升值及车辆脱离护拦时的弹出角等结果是从乘员风险和车辆轨迹等多角全面评估砼护拦的安全性能的重要依据。针对美国ＮｅｗＪｅｒｃｙ型砼护拦的实际算例与文献结果吻合较好。     

无人机光电载荷图像处理器的设计

介绍了无人机载设备的技术特点及机载小型图像处理器的组成。采用TI公司的数字信号处理器芯片为核心处理器,配合现场可编程逻辑器件(FPGA)与外部管理微控制单元(MCU)来实现目标数据的采集与处理,设计了适用于无人机光电载荷的超小型图像处理器系统。针对机载设备的特点,设计时充分考虑了体积、重量、功耗等要求。该系统已应用于多台套机载光电载荷中,工作稳定可靠,满足无人侦察机对捕捉和定位目标的要求。     

新型大面阵彩色CCD航测相机光学系统设计

介绍了一种有别于传统彩色航测相机的新型大面阵彩色CCD航测相机设计方案,该相机光学系统由Dalsa公司最新生产的6K×8K大面阵彩色CCD作为接收器.通过理论计算和ZEMAX光学设计软件的优化,给出了工作波长适应范围为0.46～0.70μm、焦距为360mm、视场角为10°、相对孔径为1∶4.3的设计实例.设计结果表明...     

Supply chain analysis under a price-discount incentive scheme for electric vehicles

We investigate an automobile supply chain where a manufacturer and a retailer serve heterogeneous consumers with electric vehicles (EVs) under a government’s price-discount incentive scheme that involves a price discount rate and a subsidy ceiling. We show that the subsidy ceiling is more effective in influencing the optimal wholesale pricing decision of the manufacturer with a higher unit production cost. However, the discount rate is more effective for the manufacturer with a lower unit production cost. Moreover, the expected sales are increasing in the discount rate but may be decreasing in the subsidy ceiling. Analytic results indicate that an effective incentive scheme should include both a discount rate and a subsidy ceiling. We also derive the necessary condition for the most effective discount rate and subsidy ceiling that maximize the expected sales of EVs, and obtain a unique discount rate and subsidy ceiling that most effectively improve the manufacturer’s incentive for EV production.     

Numerical models for vehicle exhaust dispersion in complex urban areas

Two numerical models are presented for predicting vehicle exhaust dispersion in complex urban areas with or without the wind field. The models not only reflect the effect of building and street canyon configuration on the pollutant propagation, but also are able to predict the turbulent energy produced by moving vehicles on the road. In particular, in the discrete model, turbulent energy and pollutant concentration produced by each vehicle are dynamically described in the Lagrangian method. The pollutant propagation is calculated with the advection–diffusion equation. The Reynolds averaged Navier–Stokes equations are numerically solved for the wind flows. The movement and heat release rate of the vehicles are treated as sources of the turbulent energy equation for the computation of turbulent energy produced by the moving vehicles. This paper reports the detailed implementation of the models. Four typical numerical tests were carried out to represent the performance of the proposed numerical models. Copyright © 2010 John Wiley & Sons, Ltd.