ARM11嵌入式系统实时网络通信和 PWM 波输出控制的实现

通过对ARM11嵌入式系统Linux下的实时网络通信和PWM波输出控制进行研究,分析了网络通信协议和PWM波的驱动方式。在ARM11嵌入式系统下设计了PWM波控制程序,并实现网络终端服务器和客户端双进程的工作模式,解决了网络通信实时性和可靠性的问题,以及双线程工作模式数据交互冲突的问题。实际应用表明：该方式网络通信实时性强可靠性好,ARM11和计算机的资源利用率高,可远程灵活控制PWM波的输出。     

艾亚法与兰泼凯勒法权重修正的船舶阻力预报

针对船舶阻力估算方法精度低和船型适用范围小的问题,提出一种适用于目前运输的三大主力船型的阻力预报方法,对艾亚法和兰泼凯勒法所估算的阻力值加以权重修正因子,然后将两者修正后的值相加即为最终估算的船舶阻力值,经权重修正法修正后的阻力值和试验值对比结果表明,其阻力预报精度明显提高,适用范围可扩大到目前三大主力船型。     

Application of A* algorithm for real-time path re-planning of an unmanned surface vehicle avoiding underwater obstacles

This paper describes path re-planning techniques andunderwater obstacle avoidance for unmanned surface vehicle （USV）based on multi-beam forward looking sonar （FLS）. Near-optimalpaths in static and dynamic environments with underwaterobstacles are computed using a numerical solution procedure basedon an A algorithm. The USV is modeled with a circular shape in 2degrees of freedom （surge and yaw）. In this paper, two-dimensional（2-D） underwater obstacle avoidance and the robust real-time pathre-planning technique for actual USV using multi-beam FLS aredeveloped. Our real-time path re-planning algorithm has beentested to regenerate the optimal path for several updated frames inthe field of view of the sonar with a proper update frequency of theFLS. The performance of the proposed method was verifiedthrough simulations, and sea experiments. For simulations, theUSV model can avoid both a single stationary obstacle, multiplestationary obstacles and moving obstacles with the near-optimaltrajectory that are performed both in the vehicle and the worldreference frame. For sea experiments, the proposed method for anunderwater obstacle avoidance system is implemented with a USVtest platform. The actual USV is automatically controlled andsucceeded in its real-time avoidance against the stationary underseaobstacle in the field of view of the FLS together with the GlobalPositioning System （GPS） of the USV.     

特定海域实施船舶定线制的研究路径分析

文中主要针对船舶定线制的规划和实施进行理论研究,提出实施船舶定线制研究的总体理论框架模型,引入相关评价机制和效果预测模型等理论．     

标定瞬时单位线法既有桥梁水害预报

以瞬时单位线法为基础,提出一种解决既有桥梁水害预报的水痕标定瞬时单位线法,利用历史水痕高程和对应的降雨量系列,完成瞬时单位线标定;将预报洪水雨量系列通过标定瞬时单位线对洪峰水位和洪峰滞时进行预报.在整个过程中,通过建立水位流量函数完成洪峰流量与洪峰水位之间的转换;对单位线法得到的洪水过程线的高峰流量段进行四次多项式拟合,提高预报洪峰数据精度.实例应用表明:水痕标定瞬时单位线法理论合理,应用方便,精度高,可以实现对实时水害提前预报,在保证行车安全和抗洪抢险等方面具有尤其重要的意义,预计在既有桥梁水害预报方面具有很好的应用前景.     

动车组年度高级检修量预测方法

为准确、高效地预测任意时间段内的所有动车组高级检修量,提出了一种动车组年度高级检修量预测方法.以上线动车组的既有运行规律的相关数据为初始值,计算后续高级检修具体日期和统计时间段内的高级检修量,得到上线动车组的高级检修总量.针对尚未投入使用的动车组,从宏观角度建立各个修程年度高级检修量概率计算方法,使用积分统计方法得到统计时间段内未上线动车组的高级检修总量.将2013年实际检修计划和2015年预测计划的总高级检修量进行归一化处理,进行了相关比较与误差计算.计算结果表明:当基准动车组为670组,上线日均走行公里在1000～3000 km,计算周期为180 d时,2015年归一化数据与2013年归一化数据的相对误差为-2.86％,三、四级检修的相对误差分别为-0.23％、9.24％,误差在有效范围之内,方法有效.     

TSP探测系统在隧道超前地质预报中的应用

简要介绍了TSP超前地质预报的原理和方法,结合工程实例分析了TSP探测系统的现场检测和数据处理解译技术。     

交通运输业能源消耗结构预测模型

针对交通运输业能源消耗特点,建立基于马尔科夫链的交通运输业能源消耗结构预测模型;提出依据情景假设设置转移矩阵的相关参数的计算方法;对2010～2015年交通运输业能源消耗结构进行了预测.研究结果表明到“十二五”末期,我国交通运输业能源消耗结构优化速度将进一步加快,煤炭和油品的比例逐渐下降,电力、天然气及新能源结构比例上升幅度较大.     

轨道车辆走行部机械故障预警方案研究

介绍了轨道车辆走行部机械故障监测及预警方面的发展情况,分析了列车振动特殊性,提出适用于轨道车辆的基于振动信息的SLFD(self-learning-fault-detection)故障诊断方案,并考虑影响故障预警的两大因子即运行速度和线路条件。通过仿真分析,验证了此方法的可行性。通过设计与轨道车辆走行部等效的机械试验装置,进一步验证该方法的有效性。     

Introducing Willingness‐to‐pay for Noise Changes into Transport Appraisal: An Application of Benefit Transfer

Abstract

Numerous research studies have elicited willingness‐to‐pay values for transport‐related noise. However, in many industrialized countries including the UK, noise costs and benefits are still not incorporated into appraisals for most transport projects and policy changes. This paper describes the actions recently taken in the UK to address this issue, comprising: primary research based on the city of Birmingham; an international review of willingness‐to‐pay evidence; the development of values using benefit transfers over time and locations; and integration with appraisal methods. Amongst the main findings are: that the willingness‐to‐pay estimates derived for the UK are broadly comparable with those used in appraisal elsewhere in Europe; that there is a case for a lower threshold at 45 dB(A)Leq,18h rather than the more conventional 55 dB(A); and that values per dB(A) increase with the noise level above this threshold. There are significant issues over the valuation of rail versus road noise, the neglect of non‐residential noise and the valuation of high noise levels in different countries. Conclusions are drawn regarding the feasibility of noise valuation based on benefit transfers in the UK and elsewhere, and future research needs in this field are discussed.