S^2 BHCA Multiple AUVs cooperation oriented control architecture

Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill ＆ simulation based hybrid control architecture （S^2BHCA） as the controller＇s design reference was proposed. It is a multi-robot cooperation oriented intelligent control architecture based on hybrid ideas. The S^2BHCA attempts to incorporate the virtues of the reactive controller and of the deliberative controller by introducing the concept of the ＂skill＂. The additional online task simulation ability for cooperation is supported, too. As an application, a multiple AUV control system was developed with three ＂skills＂ for the MCM mission including two different cooperative tasks. The simulation and the sea trials show that simple task expression, fast reaction and better cooperation support can be achieved by realizing the AUV controller based on the S^2BHCA.     

比例先行数字PID控制器的仿真

主要描述了通过比例先行的PID控制器,使用采样控制系统对惯性热工对象进行控制这一过程的仿真,并对仿真结果进行了简单的分析.     

特种筒形桅杆风压试验

锥形筒形桅杆是一种新型桅杆 ,由于其结构的特点 ,风载可能对它产生较大的威胁。通过四面锥状筒型桅杆的风洞试验 ,研究了桅杆模型在不同风向下 ,在雷诺数 1 .7× 1 0 5 Re 7.8× 1 0 5的范围中 ,其周向与轴向的表面压力分布 ,给出了桅杆模型表面压力系数沿周向与轴向的变化规律 ,并作了分析 ,阐明了其与风向、雷诺数之间的关系。通过桅杆模型表面压力的周向积分 ,得到了模型的升力与阻力 ,导出升力系数与阻力系数 ,并分析了二者随雷诺数及风向的变化规律。试验分析结果表明 :压力系数沿轴向的分布不均匀 ,靠近桅杆模型的中间部位 ,压力系数较大 ;在桅杆模型的两端 ,压力系数较小。压力系数沿周向的分布与风向有关 ,在迎风面上 ,压力系数最大 ,在背风面上 ,压力系数最小。升力系数与阻力系数也与风向密切相关 ,并且随着风向的变化 ,有较大的变化。在筒型桅杆设计中 ,应充分考虑到风向变化所引起的风载变化。     

潜射导弹无动力运载器的滚控暨分离技术研究

导弹水下发射无动力运载器需要滚动控制技术，但该技术在当前研制的静力分离运载器中难于实施。鉴于此，本文提出一种新的弹器分离方案－动力分离方案（即弹射分离方案），文中对动力分离运载器的结构和弹道性能作了较详细的介绍，并与静力分离方案作了较全面的比较。     

Mixed analysis of shell and solid elements using the overlaying mesh method

 This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate the effectiveness of the method. Received: August 6, 2002 / Accepted: November 25, 2002 Address correspondence to: S. Nakasumi (sumi@nasl.t.u-tokyo.ac.jp) Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:219–224; and 190:655–662)     

Dynamic Simulation of a Smart Crank and Slider Mechanism

In this paper, a smart crank and slider mechanism is analyzed mostly from a dynamic view. By means of dynamic explicit finite element method, 3D nonlinear structure is simulated. It is proved that the mechanism can effectively accomplish smart movement prescribed. And in order to ensure reciprocal movement with higher frequency, measures should be taken to avoid over heating of parts. Compared with internal energy, kinetic energy of total rigid body is dominating, and Y direction equivalent rigid velocity is much higher than X direction velocity. Equivalent rigid velocity of all parts is consistent with respective movement condition. For both energy and velocity, slider effect is dominating. Three direction equivalent inertia force oscillates. Force amplitude in Y -direction is comparitively the greatest.     

Maritime accident investigation and temporal determinants of maritime accidents: A case study

This paper presents the results of an investigation into temporal determinants of maritime accidents based on a data-set obtained from the proceedings of formal inquiries in the former German Democratic Republic (GDR). The results show that there is no statistically significant outcome between the probability for an accident and the time of watch. Thus the results do not confirm previous studies, which reported significant time of day effects.The outcome of this study indicates that marine inquiries can provide useful data for an analysis of underlying causes of maritime accidents. It is suggested that accident inquiries should be extended into the area of watch systems employed and should record the hours of work and of rest of the officers on the watch involved in a maritime accident.     

The role of professional associations in shipping

This article is in three parts. The first covers the historical development of qualifying associations. The second covers the particular role of maritime institutions that include The Royal Institution of Naval Architects, The Institute of Marine Engineering Science and Technology and The Nautical Institute. The third and final section considers the future for maritime professional associations in the context of international shipping.     

无缝设计与施工在某超长结构地下室中对砼裂缝控制应用

结合工程实践,通过对地下室砼开裂的原因进行了分析,对影响结构的耐久性和安全性的裂缝,提出处理措施。     

芦村站南端道岔群整体拨移施工

介绍芦村站南端大型道岔群整体拨移的施工方案、施工方法，阐述了施工网络图的编制，劳力的计算和分配，以及推移中可能的翻转和几何尺寸的变化等技术难点的解决要领。此项施工为铁路大提速曲线的改造和道岔群的整体拨移作了有益的偿试。