用于大功率永磁直驱电力机车驱动系统的PHM系统研究

大功率永磁直驱电力机车在线路运用考核期间需利用PHM系统跟踪驱动系统的过程数据,通过PHM系统可持续监测永磁电动机轴承温升、振动及转向架关键部件振动、位移、应力情况,深入分析永磁直驱系统的特点,充分验证大功率永磁直驱系统的可靠性,为后续大功率永磁直驱技术的推广应用提供技术数据和依据。文章介绍了用于实时监测大功率永磁直驱电力机车驱动系统的PHM系统的基本方案、系统组成和试验验证等。     

基于滚动时域优化的共享自动驾驶汽车动态调度方法

共享自动驾驶汽车被视为未来城市交通系统的重要组成部分。本文考虑随机订单需求研究共享自动驾驶汽车的动态调度优化方法。通过建立车辆调度时空网络，分别针对订单分配与空车移位生成车辆运行时间弧，提出车辆调度问题的刻画方法。基于马尔科夫决策框架，以时空节点流量为状态，以时空弧流量为决策变量，建立最大化系统净收益的车辆动态调度优化模型。 采取滚动时域优化思想，建立含前视时间窗的随机规划模型，并利用CPLEX优化引擎，滚动求解车辆动态调度决策结果。Sioux Falls网络算例结果表明，滚动时域优化方法可保证车辆动态调度决策效果，提升系统运营效率。在计算时间限制下，滚动时域方法应优先采用长时间窗中等规模 样本。在最大化系统净收益的同时进一步最小化乘客等待时间，可有效提升车辆动态调度决策效果。     

Extending Time to Collision for probabilistic reasoning in general traffic scenarios

Vehicle-to-vehicle communication systems allow vehicles to share state information with one another to improve safety and efficiency of transportation networks. One of the key applications of such a system is in the prediction and avoidance of collisions between vehicles. If a method to do this is to succeed it must be robust to measurement uncertainty and to loss of communication links. The method should also be general enough that it does not rely on constraints on vehicle motion for the accuracy of its predictions. It should work for all interactions between vehicles and not just a select subset. This paper presents a method to calculate Time to Collision for unconstrained vehicle motion. This metric is gated using a novel technique based on relative vehicle motion that we call “looming”. Finally, these ideas are integrated into a probabilistic framework that accounts for uncertainty in vehicle state and loss of vehicle-to-vehicle communication. Together this work represents a new way of considering vehicle collision estimation. These algorithms are validated on data collected from real world vehicle trials.     

快速重载运输趋势下的城轨车辆技术发展特征

随着城市化的进程,城轨交通客流强度不断增大,发车间隔不断压缩,使得我国城轨交通呈现出快速、重载、智能的发展趋势。文章结合我国目前城轨车辆快速、重载的发展状况,提出城轨车辆最大轴重的概念和建议值,且应按最大轴重对承载结构件进行设计,详细分析了城轨车辆结构件的技术发展特征,并建议应及时检测和维护车轮和钢轨,降低车、轨的振动和噪声,以提高车、轨的综合使用寿命。     

Hybrid analytic-FEM approach for dynamic response analysis of air-cushion vehicle skirts

Focused on the assessment method for dynamic behavior of the skirts of an air cushion vehicle (ACV), this paper proposes a hybrid analytic-FEM approach, within which the self-developed subroutine considers the transient skirt-water contacting force through suggested semi-analytical formula based on the empirical results from CFD simulations of the equivalent flat-plate model. The dynamic explicit algorithm of FEM is adopted to solve the large deformation problem of flexible skirts. The validity of the approach has been confirmed by comparing with previous numerical results as well as published experimental results of steady seal deformation tests at University of Michigan. Afterward, more simulations for demonstration cases are carried out to study the complex dynamic response of the skirts under different skirt-water contacting conditions. The proposed method can obtain more reliable results than traditional analytical method and be more efficient than fluid-structure interaction simulations, thus providing a practical balanced approach aiming at the dynamic response analysis for whole skirts and contributing to the skirts dynamics performance assessment of an ACV.     

多媒体网络环境下学生自主学习能力研究

在建构主义的指导下,研究发现多媒体及网络技术在教学过程中的广泛应用,既提高了学生的学习效率,又培养了学生的自主学习能力.在学习过程中,学生自己支配的时间增加,学习场所变得更加灵活,学习更富有自主性.同时,学习资源得到有机整合与充分利用.     

爆炸性气体环境生产场所的电气设计

论述了爆炸性气体生产场所电气设计工作中的一些要点,通过实例介绍了爆炸性气体生产场所电气设计工作需遵照的规范要求和采取的安全措施。     

周家嘴路车流起动波速统计研究

通过实际观测和统计分析 ,论证了平面交叉口红灯转绿灯时车流起动波速可以满足正态分布假设 ,更可以满足泊松分布假设 ,后者拟合优度高于前者。揭示了在周家嘴路条件下 ,随着车辆排队长度增加 ,起动波速会相应变大 ,呈负指数规律上升的趋势 ,与低速混合路段有明显差异。据此建议 ,如将交通流动力学模型应用于高速公路或城市高架道路一类问题时 ,状态指数取值在 2 .5左右为好。     

新型的弧焊工艺专家系统——DriAwpes1.0

以ＶＢ ｆｏｒ Ｗｉｎｄｏｗｓ为环境开发了一个新型的弧焊工艺专家系统。本系统的核心是编制焊缝的工艺件（ＷＰＳ），而在编制了每条焊缝的ＷＰＳ后，可编制施工工艺指导书（ＷＩ），在此基础上，系统的ＣＯＳＴ模块可帮助对焊件的焊接施工的工时１、消耗和成本进行估算。     

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以车辆调度问题为实例引出一种新的组合优化算法，并与原有的方法进行比较，说明新方法可以有效地抑制组合爆炸，极大地提高算法寻优效率.然后，本文用数学方法来证明该新方法再寻优上的正确性，最后根据两种不同算法编写各自对应的程序，用实际运行的结果来验证新算法带来的效率的提高.