共查询到20条相似文献，搜索用时 78 毫秒
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矿用钻孔机器人加卸钻杆位置会随主机的调姿而变化,同时在加卸钻杆路径中还存在障碍物。因此,钻孔的加卸钻杆过程存在变目标的避障轨迹规划问题。根据防爆六自由度机械手的性能参数建立DH参数表,并提出三自由度主机调姿前后加卸钻杆位置变化的函数关系。利用凸包络体结合简单几何体的包络法建立了加卸钻杆系统的碰撞检测模型,可通过欧氏距离判断是否发生碰撞。提出了三段式的加卸钻杆避障轨迹规划策略,第一段和第三段在笛卡尔空间下采用直线规划,第二段在关节空间下采用多项式插值算法进行规划,并可通过增加过渡点解决避障问题。开展了基于七次多项式插值的最小冲击避障轨迹规划算法研究,由仿真分析可知,关节角度、角速度、角加速度和角加加速度都是连续的,但绝对值峰值很大且路径较长。进一步开展了基于改进双树RRT算法、B样条路径优化及七次多项式插值的冲击优化避障轨迹规划算法研究,由仿真分析可知,不仅可保证关节角度、角速度、角加速度和角加加速度的连续性,且路径较短,角加加速度的绝对值峰值降低了98.2%。通过示教试验验证了冲击优化避障轨迹规划方法在避障、加杆轨迹规划等的可行性,机械手各关节运行曲线及运动路径与仿真结果具有较高的相似... 相似文献
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目前钻机使用的液压卡盘，大致为常闭式油压松开及常开式油压夹紧两种基本结构。而采用较多的还是前者，即蝶形弹簧夹紧、油压松开的常闭式结构。人们大多认为，这种卡盘通过弹簧力的作用来夹紧钻杆，而油压力仅用来克服弹簧力松开卡瓦。所以，对钻具的夹持力不会受液压系统的影响，一旦液压系统发生故障，停止供油，不会发生“跑钻”等事故，工作比较安全可靠。但我认为上述看法也不尽然，液压卡盘其工作性能的好坏完全在于卡盘是否具有持久、稳定及足够大的夹紧力。这种结构的卡盘是通过弹簧力作用于斜面增力机构，使卡瓦夹紧钻杆。如果钻杆或卡瓦磨 相似文献
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本文针对HCW-90型全液压自动猫道的钻杆支架起升过程进行研究,采用多体动力学与液压控制系统联合仿真方法,分析了钻杆支架起升液压缸动作的同步性对钻杆从支架末端运动至平台档销限位处的动态过程的影响。重点讨论了起升液压缸同步性对管体空间位姿、动力学参数、管体运动至终了处与档销碰撞过程。进一步分析了管体受到限位后趋于稳定的动态过程和定位精度。此外,综合考虑管体运移的快速性、平稳性和定位准确性,对起升液压缸的液压控制系统的输入信号进行了合理调整,并在满足工作性能的前提下,提出了采用分流阀构建低成本液压控制系统的方案。 相似文献
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在大直径救援井施工起下钻作业中,钻杆运移装置用于大直径钻具输送及钻柱接续。针对钻杆运移装置定位过程中钻杆易产生振动,难以快速、准确地将钻杆举升至动力头翘起角度进行对扣的问题。首先分析了钻杆运移装置的结构特点和工作原理,利用结构关系推导了钻杆举升时的运动学模型,得出钻杆末端接头与举升油缸和运移小车运动规律的映射关系,并采用有限元方法建立了钻杆举升时的动载受力模型,得出了钻杆末端接头的振动加速度主要由举升油缸和运移小车的工作速度所决定,且各部件的工作速度主要由各自的输入流量所确定;其次引入了基于模糊粒子群优化算法的综合误差评价函数,将钻杆末端接头的转角误差和位姿误差作为输入信号,采用加权法进行计算出综合误差和加速度误差,利用梯形隶属度函数构造了模糊控制规则,得出综合误差、加速度误差与比例参数、积分参数、微分参数之间关系,完成PID的控制参数调节,实现了对钻杆末端接头的主动抑振控制;最后利用MATLAB软件搭建了数值仿真模型,以某次钻杆运移装置工作时测量数据信号为例进行仿真研究,系统综合误差只需0.9 s可将振幅衰减至峰值的10%以下,同时加速度误差仅为0.05 mm/s2 相似文献
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卡盘是煤矿坑道钻机重要部件，卡盘的性能直接影响钻进的效率和质量。针对胶筒液压卡盘存在的问题，研究一种新型径向活塞式液压卡盘，通过分析径向活塞卡盘夹紧和松开系统的结构与工作原理，运用变质量液压学原理和动力学理论建立其运动过程的数学模型，并在AMESim环境下，进行了卡盘液压控制与机械系统的动力学协同仿真。在所建立的多机耦合模型基础上，详细分析了夹紧系统的响应和夹紧力特性，并搭建测试试验台进行了试验验证。研究结果表明:径向卡盘关键部件碟簧对系统特性的影响较大，通过优化碟簧性能参数，径向卡盘夹紧时间为0.325 s，松开时间为0.275 s，与胶筒卡盘夹紧时间0.325 s相当，与松开时间0.300 s接近，可与在用的胶筒卡盘互换，满足钻机功能需求，仿真结果与试验结果一致表明径向卡盘模型准确可信，为新型径向活塞卡盘系列化设计及改进提供了理论依据。 相似文献
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沟槽式卡瓦与钻杆摩擦系数的试验研究 总被引：4，自引：0，他引：4
卡瓦与钻杆之间的摩擦系数是卡盘夹紧能力计算的一个重要参数。本文介绍了该摩擦系数的一种研究方法,并通过试验研究,得出了沟槽式卡瓦摩擦系数的变化范围和取值依据,明确了影响该系数的诸多因素。本试验研究成果可直接应用于卡盘的设计计算。 相似文献
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钻机提升系统在开启和关闭时存在着严重的液压冲击现象,因而会造成钻机运行的不平稳。产生液压冲击主要是由换向阀开启和关闭时液压油和负载的动能瞬时转化为压力能而造成的。本文结合DGZ-150B型多管全方位旋喷钻机,主要介绍了通过改进提升液压系统回路和选择合理的提升速度来降低液压冲击的影响。通过利用AMESim 软件对改进前后的提升液压系统建模仿真,可以看出改进后的液压系统对液压冲击有明显的控制,系统稳定性大大提高。按照改进后的提升液压系统对钻机的提升系统进行改造,钻机在步进提升时基本感觉不到液压冲击,钻机的震动大大减轻,稳定性增强。 相似文献
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Lijie Wang Jitian Zhu Haiteng Zhuo Zhipeng Sun Aixue Song 《International Geology Review》2020,62(7-8):1108-1130
ABSTRACT Understanding fluid flow structures in a rifted basin may enhance our knowledge of their origination and evolution. Through geochemical analysis and seismic interpretation, different fluid flow features are identified in the central depression of Qiongdongnan basin, northern South China Sea. These structures include mud diapir, gas chimney, hydrothermal pipes, faults, blowout pipes, and associated extrusions. Mud diapirs are primarily located on the slope belts, whereas gas chimneys are on the basement highs in the southwest of the study area. Their distribution appears closely controlled by tectonic stress field and overpressure, the later is caused by hydrocarbon generation and compaction disequilibrium. High sediment overloading, weak post-rift tectonic activity, and high average geothermal gradient may contribute to the compaction disequilibrium. The occurrence of gas chimneys on the basement high suggests that lateral transportation and relief of overpressure is a significant factor. Distribution of broad hydrothermal pipes is related with the thinning continental crust and pre-existing boundary faults in the central depression. They are probably attributed to intruded sills dissolution and were caused by hydrothermal fluids vertically. Geochemical data from gas reservoirs analysis indicates that mud diapirs and gas chimneys are critical pathways for thermogenic gases, whereas hydrothermal pipes and part of the faults may act as pathways of both thermogenic and inorganic gases. The blowout pipes mainly occur in the northwestern central depression near the continental slope, where fluid flows ascend gradually from a series of Pliocene-current prograding wedge-formed units with a hydraulic fracture in shallow. Hundreds of seafloor pockmarks and mounds associated with blowout pipes located above the NE-SW elongated Pliocene-Quaternary slope-break belts. These extrusive structures indicate that fluids ascend through blowout pipes and were expelled at the present seabed. Our results indicate that fluid flow structures are probably responsible for fluid activities and must be taken into account when assessing the hydrocarbon potential, geologic hazard, and benthic ecosystem. 相似文献
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Asru K. Chaudhuri Joydip Mukhopadhyay Sarbani Patranabis Deb S.K. Chanda 《Gondwana Research》1999,2(2):213
The Peninsular India hosts extensive record of Mesoproterozoic, and Neoproterozoic successions in several mobile belts, and cratonic basins. The successions provide excellent opportunities for chronostratigraphic classification, in tune with the chronometric classification adopted by IUGS for inter-regional correlation on a global scale. Major tectono-thermal events at 1000–950 Ma in the mobile belts, correlatable with the Grenville orogeny may be considered as the datum for Meso-Neoproterozoic classification in India. Principles of chronostratigraphic classification, however, can not be applied yet to the cratonic successions of India because of inadequate radiometric data, paucity of biostratigraphic studies, and lack of regionally correlatable stratigraphic or palaeoclimatic datum. The kimberlite magmatism which affected the Peninsular India on a continental scale at about 1100 Ma, holds the key to the identification of Neoproterozoic successions of the cratonic basins. Thus, the stratigraphically confined diamond-bearing conglomerates and/or the tuffs associated with kimberlites, may be considered as the datum to define the base of the Neoproterozoic, fixed at about 1000 Ma. Accordingly, the Rewa, and Bhander Groups in the Vindhyan basin, the Kurnool Group in the Cuddapah basin, the Jagdalpur Formation in the Indravati basin, and the Sullavai Group in the Pranhita-Godavari basin are taken to represent the Neoproterozoic successions in the Peninsular India. The Chattisgarh Group in the central India, the lower part of the Marwar Supergroup in western Rajasthan, the Badami Group in the Kaladgi basin, and the Bhima Group are the other “possible Neoproterozoics” in the Peninsula.The closing phase of the Mesoproterozoic in all these basins are characterised by stable shelf lithologic associations attesting to high crustal stability. The Neoproterozoic basins, by contrast, mark a new phase of rifting, and extension, and the basin fills exhibit signatures of initial instability which evolved with time into a more stable platformal condition. A major episode of sea level rise has been recorded in most of the basins. The riftogenic origin, and evolution of the basins are comparable with the history of Neoproterozoic basins of Australia though there is no unequivocal record of glaciation in the Indian formations. 相似文献
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江苏省太仓市污水改造工程污水管铺设的精度要求很高，而且采用的双壁空心PE管抗拉强度低，对于现有的非开挖铺管技术是一种挑战。介绍了该工程的施工难点以及设计要点，同时对施工中遇到的问题进行了分析总结。 相似文献
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用分段定向钻进方法铺设弧形轨迹集束管 总被引：1，自引：0，他引：1
横穿开洛高速公路６５．４ｍ,贯通９个收费亭人井,１１段路基,按路面形状成中间高,两端低的菜钻孔;多级扩孔至孔径５００ｍｍ,在其中铺设Х１１４ｍｍ钢管４根,Х６０ｍｍ钢管３根。两组这样的管束平行间距始终保持４５０ｍｍ,按轨迹设计要求,准确无误的到达出口。 相似文献
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Change of groundwater chemistry from 1896 to present in the Mid-Levels area, Hong Kong 总被引：1，自引：0，他引：1
In this study, groundwater quality information collected in 1896 (well waters), 1980/1981 (piezometric and seepage samples)
and 2002/2003 (seepage samples) in the regions centered by the Mid-Levels area, Hong Kong Island, was compared to illustrate
how groundwater quality has changed over a century and the processes controlling it. As shown by saline ammonia and nitrate
levels in the late nineteenth century, groundwater was severely polluted by widespread and obvious leakage from poorly designed
wastewater collection systems, although groundwater was still a drinking water source for local residents. The extremely high
residual chlorines in groundwater demonstrated that large doses of disinfection agents were added to wells at that time. In
view of the decline in saline ammonia and nitrate levels, groundwater became less organically polluted in the 1980s probably
due to significant improvement of the design of underground sewers. However, more leakage from sources such as salty flushing
water and fresh water pipes emerged in the past few decades which added complexity to groundwater chemical systems. Some chemicals
were used to identify possible locations of leakages. The temporal variations of the distribution of these chemicals over
the area may shed light on the rate of leakage. Leakage from service pipes seems to have improved from the early 1980s to
2002/2003. However, the area is still suffering from widespread and small-scale leakage from service pipes. More efforts should
be paid to control small leakages in the future. The findings will be instructive to various government organizations such
as the Water Supplies Department and Drainage Services Department to identify possible locations of unobvious leakages in
the area. 相似文献