一种具有鲁棒性的海浪干扰滤波器

  目的  潜艇在复杂海况下进行水面航行时,为实现低噪操舵控制,  方法  采用潜艇水平面线性运动模型,并利用基于双幂次趋近律的滑模控制对参数变化和外部干扰不敏感、响应速度快、容易实现等优点,设计航向控制器。针对海浪干扰问题,利用非线性扩张状态观测器（NESO）设计海浪滤波器,用以补偿系统外部干扰。  结果  理论推导结果证明了航向滑模控制器的稳定性,并通过Matlab仿真结果验证了其良好的滤波效果。  结论  研究结果表明,该航向滑模控制器在不同航速、不同海况、不同浪向下均可实现低噪、快速、高精度的航向控制性能。     

Development of control models for the planning of sustainable transportation systems

Planning of sustainable transportation systems requires integration of multiple systems while considering a holistic approach. A limited amount of research has been conducted that simultaneously considers all the transportation, economic activity, environmental and social effects. The proposed research envisages incorporating considerations related to sustainability and providing solutions to stakeholders in policy making. In this paper, a dynamic model for planning and development of sustainable transportation systems is presented. This is given by a system of three nonlinear differential equations representing the dynamics of the three independent states, namely, transportation, activity, and environmental systems. A policy scenario considering investment in energy efficient technologies and its effects on the states is discussed to assist making investment decisions. Optimal control techniques are used to design the controls. The results show that it is possible to formulate an optimal control to achieve the desired target. Numerical results, based on actual parameters, are presented to illustrate the long-term trends of the states. The methodology discussed in this paper will be helpful to decision makers in making optimal decisions. The contribution of this research work is the introduction of a systems and controls methodology to develop optimal policies for the design of sustainable systems.     

Coloured Petri net-based traffic collision avoidance system encounter model for the analysis of potential induced collisions

The Traffic Alert and Collision Avoidance System (TCAS) is a world-wide accepted last-resort means of reducing the probability and frequency of mid-air collisions between aircraft. Unfortunately, it is widely known that in congested airspace, the use of the TCAS may actually lead to induced collisions. Therefore, further research regarding TCAS logic is required. In this paper, an encounter model is formalised to identify all of the potential collision scenarios that can be induced by a resolution advisory that was generated previously by the TCAS without considering the downstream consequences in the surrounding traffic. The existing encounter models focus on checking and validating the potential collisions between trajectories of a specific scenario. In contrast, the innovative approach described in this paper concentrates on quantitative analysis of the different induced collision scenarios that could be reached for a given initial trajectory and a rough specification of the surrounding traffic. This approach provides valuable information at the operational level. Furthermore, the proposed encounter model can be used as a test-bed to evaluate future TCAS logic changes to mitigate potential induced collisions in hot spot volumes. In addition, the encounter model is described by means of the coloured Petri net (CPN) formalism. The resulting state space provides a deep understanding of the cause-and-effect relationship that each TCAS action proposed to avoid an actual collision with a potential new collision in the surrounding traffic. Quantitative simulation results are conducted to validate the proposed encounter model, and the resulting collision scenarios are summarised as valuable information for future Air Traffic Management (ATM) systems.     

我国铁道列车紧急制动距离限值标准的探讨

基于推荐的铁道列车紧急制动距离限值的核定原则和参数选择,通过对高速列车、快速列车、普通旅客列车、快速货物列车和普通货物列车的紧急制动距离限值的计算与比较,证实"铁路技术管理规程"中有关现行列车紧急制动距离限值的规定相对合理,但120km·h-1的普通旅客列车和快运货物列车的紧急制动距离限值较推荐标准为低,建议予以调整。推荐的高速列车紧急制动距离限值标准可供高速列车制动系统设计参考。     

国内外铁路轮对组装标准的对比分析

主要介绍国际、国外和我国铁道行业标准中轮对标准的架构，对比分析国际、国外和我国铁道行业标准轮对组装标准的内容，提出对采用国际、国外标准的建议。     

沥青混凝土搅拌设备标准理论试验工况的研究

沥青混凝土搅拌设备的工作条件、工作对象等工况参数是一个经常变化的量，直接影响设备的性能指标，因此需用标准定义下的工况参数予以修正。文章主要介绍了标准级配配比、沥青标号、冷集料含水量及初始温度、出料温度、大气状况等标准理论试验工况的确定。     

联合破碎设备设计和使用中的若干问题

在道路铺筑中,所用石料的规格对公路质量有着很大的影响.在分析高等级公路施工中石料的一些具体规格要求的基础上,讨论了联合破碎机生产能力的确定和选择.     

城市公交场站设施规划

公交场站设施是重要的城市基础设施.本文重点探讨城市公交场站设施规划建设方面的一些问题,包括公交场站发展的规模、场站规划设置标准、场站建设模式等,并提出了相关的意见和建议.     

PSPC在船舶建造中的应用研究

通过对涂层性能新标准(PSPC)的分析和研究,在船舶建造的前期策划过程中,从船舶设计、工法设计、生产管理等各方面,分解涂层性能新标准(PSPC)各项要求到各个工序,再通过现场施工检验,进一步优化整个实施体系。     

车辆阻力对站线坡度设计的影响研究

根据车辆所受基本阻力、曲线阻力、坡道阻力、风阻力、道岔阻力,建立车辆单位基本阻力模型及数学表达式,运用车辆参数及风阻力参数,对车辆相关状态进行分析计算,研究表明:线路纵坡即使为平坡,亦存在溜逸安全隐患,必须采取措施才能保证安全;对《站规》站线纵坡标准,进行安全评估,提出利用停车顶改善车辆停放状态的措施意见及计算办法;利用减速顶做功耗能可以提高装车线线路纵坡,从而满足定量快速装车或轨道衡计量系统的技术要求,为线路纵坡设计提供依据,拓宽站场调速设备应用领域,创新工程设计方法,为工程综合优化设计提供理论基础,供设计分析及计算参考。