USV发展现状及展望

  目的  无人艇（USV）在复杂环境情况下会出现偏离目标航线的情况,为提高水面无人艇的抗干扰能力及实际航行的稳定性,实现对航迹的准确控制,提出一种改进的无人艇航迹控制方法。  方法  根据导航信号受环境影响的情况,对GPS信号有效和无效2种情况下的航迹控制分别进行分析,在自主可控平台上设计并实现了基于模糊控制可变船长比的视线导引算法（LOS）和自抗扰航向控制器(ADRC)相结合的航迹控制方法,并开展了双桨双舵无人艇湖上试验。  结果  仿真结果表明：该方法可满足航迹控制的要求,转弯后航向能够快速保持稳定,无频繁摆舵现象,且该方法能够完成真实环境下的航迹控制,航迹贴线误差均值约为0.1 m,方差约为0.03。  结论  湖上试验结果验证了该算法在实际工程应用中的可行性和有效性。     

重力式方块卸荷板大型构件出运码头升级改造

以工程实例介绍了重力式方块卸荷板码头的改造设计方案。由于原有码头卸荷板悬臂较大,在码头前沿均布荷载增大的情况下,使得基床顶面产生较大的后倾应力,基床承载力不满足规范要求。改造方案通过在后方设灌注桩及现浇钢筋混凝土板,减少码头卸荷板悬臂部分上部荷载,防止基床顶面产生较大的后倾应力,为类似的码头改造设计提供了借鉴。     

无人帆船循迹航行的控制研究

提出一种适用于无人帆船循迹航行的控制器,并应用于一条1.5m长风帆艇的湖上航行测试。该控制器包含三个独立模块,局部路径策略模块决定帆艇的转向过程;帆自动控制模块根据帆位角和相对风向角的对应关系获取最佳推进力;舵自动控制模块基于从航海经验中提炼的245条模糊控制规则实现航迹调整。1.5m帆艇的湖上测试结果表明,该控制器在多种风场条件下都可有效完成帆艇的循迹航行,具有在无人帆船上实现长程航行的应用前景。     

球扁钢肋骨三角形加热仿真研究

针对球扁钢肋骨三角形加热矫正纵向弯曲变形,利用ANSYS软件和APDL语言编写仿真程序,实现了热-结构耦合场的数值模拟,得到了加热过程中温度场和结构场的求解结果。对于不同的加热速度与气流输入量,计算了肋骨表面最高温度和高度方向的变形量,利用MATLAB曲面拟合,得到了最高温度和变形量关于加热速度和气流流量的函数。并对这两个参数进行了优化,得到了满足温度约束下变形量最大的参数组合。研究内容和结果对球扁钢肋骨三角形加热的更深入研究和现场施工提供了一定的参考和指导。     

优化GM（1,1）模型在连续刚构桥施工监控中的应用

文章结合优化GM（1,1）模型用于罗天乐大桥施工监控的工程实例,介绍了优化GM（1,1）模型的原理、计算方法及计算过程,并根据实际监控经验提出了建议。罗天乐大桥的具体施工监控实践表明,优化GM（1,1）模有着较高的预测精度,能较好地应用于大跨度连续刚构桥的施工监控。     

双薄壁墩连续刚构顶推力研究

文章结合深圳轨道交通某双薄壁墩连续刚构工程实例,阐述了确定连续刚构中跨合拢时顶推力大小的方法,并且对顶推前后连续刚构的受力特性进行了研究,其基本思路、方法和成果可供类似桥梁结构的设计施工参考。     

贝雷架钢桥的静动力荷载试验研究

文章结合工程实例,通过对贝雷梁桥梁静动力荷载试验,指出贝雷架钢桥连接部分存在联系不够紧密、桥梁横向分配性较差、桥面的振动感觉明显及钢梁易锈蚀等问题。提出了改善贝雷架钢桥结构的力学性能和使用状况,加强结构的定期检查及监测等相关建议。     

物联网平台下智能交通系统体系框架研究

文章以现有智能交通系统体系框架为基础,提出以结构化方法制定物联网平台下智能交通系统体系框架,并以结构化方法的基本步骤为主线,结合物联网工作原理和自主体系结构,从用户服务、逻辑框架、物理框架三方面探讨新体系框架与现有体系框架的差别。     

A proposal for cost-related and market-oriented train running charges

This paper examines some key aspects of a charging system for promoting railway transport, including charges reflecting a clear relationship with costs (transparency) and charges reflecting the quality of the infrastructure manager's service. Train running charges recover track-related costs and can help to develop a charging system that meets these requirements. To orient train running charges to the market, a method for processing track maintenance and renewal costs is proposed whereby the quality of the service provided by an infrastructure is measured according to its utility to the railway undertaking. To achieve transparency, a single indicator is used for cost planning and the subsequent levying of costs on railway undertakings. The paper includes an example of how proposed train running charges would be calculated according to data from 14 European countries. The example shows that short-distance trains generate the lowest maintenance and renewal costs, followed by long-distance trains and freight trains.     

A practical capacity model of a single track line

The paper presents a model for determining the practical capacity of a single track line, i.e. the maximum number of trains which can be run along it in a time unit under the condition that each train enters its bottleneck segment with a definite delay.

The input data used in the model are: geometrical characteristics of the bottleneck segment of the line under study, the intensity and structure of demand expressed by a number of trains which are run over the line in a given time unit, the scenario of traffic running over the line under study and the operational tactics of individual train categories processing on the bottleneck segment.

(Two tactics can be applied in the train processing on the line under study; first, the trains of individual categories are given different priorities in the processing, and second, all the trains have the same priority).

The output results of the model are average delays of trains of each category occurring within the train processing performed on the bottleneck segment of the line under study in a given time unit.