Computing collision-free motions for a team of robots using formation and non-holonomic constraints

This paper focuses on the collision-free motion of a team of robots moving in a 2D environment with formation and non-holonomic constraints. With the proposed approach one can simultaneously control the formation of the team and generate a safe path for each individual robot. The computed paths satisfy the non-holonomic constraints, avoid collisions, and minimize the task-completion time. The proposed approach, which combines techniques from mathematical programming and CAD, consists of two main steps: first, a global team path is computed and, second, individual motions are determined for each unit. The effectiveness of the proposed approach is demonstrated using several simulation experiments.     

A distributed control scheme for multiple robotic vehicles to make group formations

This paper presents a novel distributed control scheme of multiple robotic vehicles. Each robotic vehicle in this scheme has its own coordinate system, and it senses its relative position and orientation to others, in order to make group formations. Although there exists no supervisor and each robotic vehicle has only relative position feedback from the others in the local area around itself, all the robotic vehicles are stabilized, which we have succeeded in proving mathematically only in the cases where the attractions between the robots are symmetrical. Each robotic vehicle especially has a two-dimensional control input referred to as a “formation vector” and the formation is controllable by the vectors. The validity of this scheme is supported by computer simulations.     

北部湾盆地流沙港组湖相烃源岩的差异

北部湾盆地是中国近海重要的富油盆地,油气发现主要集中于涠西南凹陷、乌石凹陷和福山凹陷,探明原油地质储量约为4.05×10⁸t,但各个主要凹陷的探明油气地质储量存在显著差异。北部湾盆地各凹陷的油气富集程度与其湖相烃源岩的差异密切相关,从涠西南凹陷到乌石凹陷,再到迈陈凹陷和福山凹陷,古近系流沙港组烃源岩的品质总体下降,烃源岩的有机质丰度降低,有机质类型从以腐泥型为主变成以混合型占优势,烃源岩的生烃潜力下降。分析表明,尽管北部湾盆地流沙港组烃源岩在形成期各凹陷普遍具有较高的古湖泊有机质生产力,但各凹陷的有机质来源仍然存在差异,有机质保存条件也存在差异,从涠西南凹陷到乌石凹陷,再到迈陈凹陷、福山凹陷和海中凹陷,湖相藻类来源的有机质减少,陆生高等植物来源的有机质增加,有机质保存条件具有变差的趋势。     

柴西南红柳泉地区古近系下干柴沟组下段浅水三角洲控砂特征

浅水三角洲发育的骨架砂体是岩性油气藏形成的有利储集体.运用古构造恢复技术,对柴达木盆地西南部红柳泉地区古近系下干柴沟组下段（E13）沉积时期内的古地形、古气候及古水体进行了分析,并探讨了砂体分布主控因素.结果表明：红柳泉地区在E13沉积时期具有盆浅湖阔的古构造背景,地形坡度相对较小,古水深一般小于10m,水体动荡,湖平面变化相当频繁,物源充足,具备形成浅水三角洲的古沉积环境;浅水三角洲的砂体受挠曲坡折带和湖岸线的联合控制;红柳泉断层活动引起的挠曲坡折带形成低幅度的隆起区,控制了古水流的分叉改道;湖岸线是水上和水下环境的分界线,在平面上控制了分流河道和水下分流河道的分布,在纵向上响应于相对湖平面的上升和下降,可形成多个储盖组合,配合湖岸线对砂体物性的影响可形成封堵性能良好的成岩砂岩体圈闭.     

地层测试资料在措施选层中的应用

试油评价在认识油藏物性变化、油藏形状等方面具有独特的优势,试油评价数据结合录井、测井、构造、沉积等地质资料能更准确地认识地层及油藏,可为措施选层提供正确的方向,为确定措施参数提供依据。将地层测试资料应用于措施选层,已见到了良好的效果,有着广阔的应用前景。     

利用“四性”关系识别建南构造东岳庙段页岩气储层

建南构造侏罗系下统自流井组东岳庙段泥页岩发育,邻井多口井在该段普遍见良好的油气显示。页岩气储层为自生自储型油气藏,属于泥岩性质储层,具有低孔隙、超低渗透率的特点。对建南构造自流井组东岳庙段页岩气储层岩性、物性、电性、含气性特征及储层"四性"关系的研究,结合岩心、气测录井、试气等资料统计分析出页岩气储层的物性和电性下限值,进一步建立有效厚度解释图版,可定量得出页岩气层的解释下限标准。     

对江陵凹陷荆沙组油气勘探前景的重新认识——基于沙26-8井的成果启示

长期以来,江陵凹陷油气勘探以深层新沟嘴组和白垩系为重点,对荆沙组地层未作系统分析与评价,其基本成藏条件研究不深入,勘探潜力不明确。近期沙26-8井在荆沙组的钻探取得重大突破,明确荆沙组具有一定的成藏条件,使得荆沙组成为研究重点和储量增长新的勘探目的层。     

保山盆地永铸街气田沉积物源分析

根据研究区的基本资料和相应成果,在分析保山盆地基本构造格局的基础上,发现因保山盆地主控断层的西边在盆地演化过程中一直处于隆升状态,从而造成不同地带砾岩的分布和含量存在差异,在钻测井、地震资料中的体现也不相同.通过多种方法对永铸街气田的主物源方向进行论证后,认为永铸街气田的物源来自西边.     

Rare Earths, Trace Element Characteristics of High-Mg Volcanic Rocks of Yixian Formation in Sihetun West Liaoning Province and Its Apocalypse

The high-Mg volcanic rocks of the Yixian Formation in the Sihetun area have the obvious characteristics of mantle-derived lava in rare earth, trace element characteristics with high Mg# (62～70) and high content of compatible elements. In the meantime, the volcanic rocks also have the obvious characteristics of Crust-source material in rare earth, trace element characteristics with high ∑REE (158.78×10-6～359.66×10-6), high (La/Yb)N (14.61～29.60), high La/Nb(2.37～7.52) and high Ba/Nb(67.58～205.96), obvious positive anomaly of Pb and negative anomaly of Nb, Ta in trace element spider-gram. In Sr-Nd-Pb isotope the (87Sr/86Sr)i ratio is higher than 0.706 and the εNd(t) ratio is from -3.4 to -13, both reflect enriched Mantle characteristics. The characteristics above of the volcanic rocks combined with the content of Sr, Ba, Y, Yb and the ratio of Sr/Y show that the volcanic rocks have the property of the Sanukite rocks in Setouchi Japan beside subduction zone, and illuminate that the Sanukite rocks can be formed not only in island-arc near subduction zone but also in intro-plate. The analysis indicates that the high-Mg volcanic rocks in the Sihetun area result from the collective function of mantle-derived lava and crust-source materials. The result illuminates that the West Liaoning region is very special in tectonic geochemical background in Cretaceous in East China, and is an ideal region for us to further study the characteristics of magmatic activity as well as the process of Crust-Mantle interaction in Eastern China.     

地震资料预测地层破裂压力的方法

介绍了利用地震资料预测地层破裂压力的方法。该法主要是先从地震资料中提取地层速度 ,然后预测地层孔隙压力 ,在此基础上按一定的模式进行地层破裂压力的预测。该方法在塔里木和吐哈油田两个构造上应用 ,预测精度达 90 %以上 ,能满足工程需要。