50 resultados para robotic swarm


Relevância:

10.00% 10.00%

Publicador:

Resumo:

本文为工业机器人提出了一种极点配置控制法.这种控制方法的优点有:一是它的积分作用消除了机器人的微小扰动和稳态误差;二是能任意设置系统的极点,因此能保证闭环系统的稳定性和规定状态变量的暂态响应;三是加入了加速度反馈,抑制了由电枢电感所引起的机械手的振动.最后,给出了PUMA562机器人的计算机仿真和实验结果验证了此控制法的有效性。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

视觉检测技术是随着计算机视觉技术和光电技术的飞速发展,而出现的一种新的检测技术。检测被测目标时,把图像当作检测和传递信息的手段或载体,从图像中提取有用的信号,它是以现代光学为基础,融光电子学、计算机图像学、信息处理、计算机视觉等科学技术为一体的现代检测技术。现代激光自动化焊接技术是由激光、计算机、机器人、数控和精密机床等相结合的综合高新技术,此项技术已成为工业生产自动化的关键技术,拥有普通加工技术所不能比拟的优势。为了克服机器人焊接过程中各种不确定因素对焊接质量的影响,提高机器人作业的智能化水平和工作可靠性,要求焊接机器人系统不仅能实现空间焊缝的实时跟踪,而且还能实现焊接参数的在线调整和焊缝质量的实时控制,即焊接机器人焊接过程的自主化和智能化。本文的研究依托于中国科学院知识创新工程方向性项目“全自动激光拼焊成套装备生产线”,旨在探索立体视觉检测系统的实现及其在激光拼焊工程中的应用的问题。从理论和实践两个方面,对其中的若干关键技术,如视觉检测系统创新设计、数学模型、量化误差、摄像机标定、结构光条纹中心线提取、焊前特征检测、溶池边缘提取、焊后缺陷图像匹配算法、三维重建和表面孔的视觉定位等进行了研究。主要研究成果如下: 1.提出了一种可以用于焊前跟踪,焊后检测,以及焊接过程中对激光溶池进行监测的多功能激光视觉检测装置。推导了检测系统在不考虑像平面安装倾斜角度时和考虑像平面安装倾斜角度时检测点坐标的计算公式以及量化误差公式,分别针对由于数模转换量化误差、安装角度倾斜误差、安装高度误差三个方面引起的量化误差,分析其关于行,列,以及不同倾斜角度的影响分布规律。并对于各种情况进行了仿真,对于各种误差分布特征进行了分析,提出了检测奇异点的情况和数学模型的局限性。以上工作为实现焊缝三维信息的高精度提取奠定了基础。 2.对于摄像机的标定技术进行了研究,结合工程实际,利用zhang的标定法和matlab标定工具包,对于摄像机进行了标定;针对检测相机视场较小,标定采集范围不易调整和相机的畸变主要发生在视场边缘等特征,在保证要求的精度范围之内,提出一种基于标定靶的标定方法,实验证明该方法的标定与测量精度能够满足工程需要。 3.研究了现有的条纹中心提取算法过程,提出了基于OTSU阈值的多次高斯拟合平均法和基于OTSU阈值的质心平均法计算激光条纹中心坐标。该法对条纹的噪声,散斑和被测工件表面漫反射有很强的抵制作用,因此具有很强的鲁棒性。实验表明,与传统方法相比,具有更高的提取精度。同时为了适应激光条纹被工件表面调制后发生的角度变化,以及硬件安装带来的激光线型条纹倾斜,提出了一种自适应方向模板法,可以解决特殊倾斜角度时的激光条纹中心线提取问题。三个仿真试验验证了方法的可行性。 4.提出了一套在线实时进行焊前检测的图形处理算法,可以实现焊缝宽度,焊前错配和焊缝中心位置检测。通过工程实验提取了各指标的检测结果,并验证了算法的正确性。 5.提出了一种基于数学形态学的激光拼焊溶池边缘检测算法,对于激光拼焊中的溶池图像进行边缘提取,基于真实图像进行了实验研究表明,提取边缘效果可以达到单像素。 6.对焊后表面形貌检测的图像实时处理算法进行了研究。提出了一套在线实时进行焊后焊缝表面缺陷检测的图形处理算法,可以进行焊缝宽度,错配,凹度,凸度,咬边,焊接倾角,过高七种表面焊接缺陷的匹配识别;对于整个焊缝的表面形貌进行三维重建。通过等厚板焊接和不等厚板焊接两种试验,验证了算法的合理性和鲁棒性。提出了一种基于randon变换的错配和兴趣区域快速检测算法。对于表面孔的检测算法进行了探讨,主要针对孔的检测中的噪声和表面反射,研究了腐蚀膨胀对于表面孔定位和大小的检测影响。 7.研究了以普通6R机器人进行焊缝视觉检测的工作视野,即焊缝视觉检测空间,提出了一种生成焊缝视觉检测空间的解算法;以此检测视野为依托,探索了在视觉检测视野中进行焊缝视觉检测的初始位置规划问题,提出了一种初始位置规划算法;仿真结果证明了算法的正确性。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Bayan Obo giant REE-Nb-Fe deposit in the northen margin of the North China Craton (NCC) is well known in the world for its abundant rare earth element resources. There is nearly one hundred year of studying history in substance component, chronology and geochemistry of the ore deposit, since the main ore body was found in 1927. However, there still exist remarkable divergences in genesis, mineralized age and material origin. Especially the REE enrichment mechanism leaves us a secret. Recent research shows that the Bayan Obo ore deposit likely resulted from the carbonatite magma activity, which is a favorable factor for REE accumulation. Based on the analysis of tectonic evolution history of north margin of NCC this thesis mainly discussed the formation background of cratonic margined rifts in Bayan Obo, and presented the analytical results of formation environment, intrusion age and deep origin of Proterozoic carbonatite magma. These research results can provide evidence for ore genesis. LA ICP-MS U-Pb dating on zircon shows that the Neoarchean basement was mainly composed of calc-alkaline TTG gneisses (2588±16Ma). The collision orogeny movement of the northen margin of the NCC between 2.0 Ga to 1.9 Ga brought the swarm of diorite-granodiotite magma (2023±16Ma) and intense regional metamorphism event (1906.3±7.7 Ma to 1892.7±6.7 Ma). In the sequent super continent break up background, intense metamorphic and deformed basement complex was uplifted to the surface suffered denudation, forming Mesoproterozoic Bayan Obo group in the contemporary continental margin rifts. The uplift of basement complex and formation of continental rifts were likely related with mantle plume activity. Evidence from petrological and geochemical data suggests that abundant alkaline-basic magma resulted from enhancement of continental breakup activity, that separated into carbonatite veins and mafic dykes by melt immiscibility mechanism, intruded in Bayan Obo margin rifts at the late stage of extension movement. Carbonatite veins can be divided into three main types by mineral composition: dolomite carbonatite, dolomite-calcite coexistent carbonatite and calcite carbonatite. Intrusion relationship between different types of carbonatite veins show that the calcite carbonatite veins were formed latter than the dolomite type as well as the coexistent type. Moreover, geochemical data also reveals successive and evolutive character between them. The content of REE increases together with the calcite minerals component. That is to say that REE gradually accumulated as the evolution of carbonatite magma. High precision Sm-Nd isochron data shows that the intrusion age of carbonatite veins was at 1319±48Ma. Moreover, the REE mineralization age in calcite carbonatite veins was around 1275±87Ma that is consistent with the intrusion age in error range. According to these data the abundant REE already existed in the carbonatite magma before intrusion and result in the earlier ore mineralization. The average age of mineralized dolomite was at 1353±100Ma, and the mineralization age of apatite in coarse grain dolomite was around 1329±150Ma. These data is consistent with carbonatite. Considering the coincident rare, trace element and isochron composition between them, it is presumed that mineralized dolomite was also the carbonatite intrusion and was the mainly factor for huge REE enrichment.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In recent years, chimney structure has been proved one of important indicators and a useful guide to major petroleum fields exploration through their exploration history both at home and abroad. Chimney structure, which has been called "gas chimney" or "seismic chimney", is the special fluid-filled fracture swarm, which results from the boiling of active thermal fluid caused by abruptly decreasing of high pressure and high temperature in sedimentary layers of upper lithosphere. Chimney structure is well developed in continental shelf basin of East China Sea, which indicates the great perspectives of petroleum resources there. However, the chimney structure also complicated the petroleum accumulation. So the study of chimney structure on its formation, its effect on occurrence and distribution of petroleum fields is very important not only on theoretical, but also on its applied research. It is for the first time to make a clear definition of chimney structure in this paper, and the existence and practical meaning of chimney structure are illustrated. Firstly, on the viewpoint of exploration, this will amplify exploration area or field, not only in marine, but also on continent. Secondly, this is very important to step-by-step exploration and development of petroleum fields with overpressure. Thirdly, this will provide reference for the study on complex petroleum system with multi-sources, commingled sources and accumulation, multi-stage accumulations, and multi-suits petroleum system in the overlay basin. Fourthly, when the thermal fluid enters the oceanic shallow layer, it can help form gas hydrate under favorable low-temperature and high-pressure conditions. Meanwhile, the thermal fluid with its particular component and thermal content will affect the physical, chemical and ecological environments, which will help solving the problem of global resources and environment. Beginning from the regional tectonic evolution characteristics, this paper discussed the tectonic evolution history of the Taibei depression, then made an dynamical analysis of the tectonic-sedimentary evolution during the Mesozoic and Cenozoic for the East China Sea basin. A numerical model of the tectonic-thermal evolution of the basin via the Basin-Mod technique was carried out and the subsidence-buried history and thermal history of the Taibei depression were inverse calculated: it had undergone a early rapid rift and sag, then three times of uplift and erosion, and finally depressed and been buried. The Taibei depression contains a huge thick clastic sedimentary rock of marine facies, transitional facies and continental facies on the complex basement of ante-Jurassic. It is a part of the back-arc rifting basins occurred during the Mesozoic and Cenozoic. The author analyzed the diagenesis and thermal fluid evolution of this area via the observation of cathodoluminescence, scanning electron microscope and thin section, taking advantage of the evidences of magma activities, paleo-geothermics and structural movement, the author concluded that there were at least three tectonic-thermal events and three epochs of thermal-fluid activities; and the three epochs of thermal-fluid activities were directly relative to the first two tectonic-thermal events and were controlled by the generation and expulsion of hydrocarbon in the source rock simultaneously. Based on these, this paper established the corresponding model between the tectonic-thermal events and the thermal-fluid evolution of the Taibei Depression, which becomes the base for the study on the chimney structures. According to the analyses of the gas-isotope, LAM spectrum component of fluid inclusion, geneses of CO_2 components and geneses of hydrocarbon gases, the author preliminarily verified four sources of the thermal fluid in the Taibei Depression: ① dehydration of mud shale compaction, ② expulsion of hydrocarbon in the source rock; ③ CO_2 gas hydro-thermal decomposition of carbonatite; ④magma-derived thermal fluid including the mantle magma water and volatile components (such as H_2O, CO_2, H_2S, SO_2, N_2 and He etc.). On the basis of the vitrinite reflectance (Ro), homogenization temperature of fluid inclusion, interval transit time of major well-logging, mud density of the wells, measured pressure data and the results of previous studies, this paper analyzed the characteristics of the geothermal fields and geo-pressure fields for the various parts in this area, and discussed the transversal distribution of fluid pressure. The Taibei depression on the whole underwent a temperature-loss process from hot basin to cold basin; and locally high thermal anomalies occurred on the regional background of moderate thermal structure. The seal was primarily formed during the middle and late Paleocene. The overpressured system was formed during the middle and late Eocene. The formation of overpressured system in Lishui Sag underwent such an evolutionary process as "form-weaken-strengthen-weaken". Namely, it was formed during the middle and late Eocene, then was weakened in the Oligocene, even partly broken, then strengthened after the Miocene, and finally weakened. The existence of the thermal fluid rich in volatile gas is a physical foundation for the boiling of the fluid, and sharply pressure depletion was the major cause for the boiling of the fluid, which suggests that there exists the condition for thermal fluid to boil. According to the results of the photoelastic simulation and similarity physical experiments, the geological condition and the formation mechanism of chimnestructures are summarized: well compartment is the prerequisite for chimney formation; the boiling of active thermal fluid is the original physical condition for chimney formation; The local place with low stress by tension fault is easy for chimney formation; The way that thermal fluid migrates is one of the important factors which control the types of chimney structures. Based on where the thermal fluid come from and geometrical characteristics of the chimney structures, this paper classified the genetic types of chimney structures, and concluded that there existed three types and six subtypes chimney structures: organic chimney structures generated by the hydrocarbon-bearing thermal fluid in middle-shallow layers, inorganic and commingling-genetic chimney structures generated by thermal fluid in middle-deep layers. According to the seismic profiles interpretations, well logging response analysis and mineralogical and petrological characteristics in the study area, the author summarized the comprehensive identification marks for chimney structures. Especially the horizon velocity analysis method that is established in this paper and takes advantage of interval velocity anomaly is a semi-quantitative and reliable method of chimney structure s identification. It was pointed out in this paper that the occurrence of the chimney structures in the Taibei depression made the mechanism of accumulation complicated. The author provided proof of episodic accumulation of hydrocarbon in this area: The organic component in the boiling inclusion is the trail of petroleum migration, showing the causality between the boiling of thermal fluid and the chimney structures, meanwhile showing the paroxysmal accumulation is an important petroleum accumulation model. Based on the evolutionary characteristics of various types of chimney structures, this paper discussed their relationships with the migration-accumulation of petroleum respectively. At the same time, the author summarized the accumulating-dynamical models associated with chimney structures. The author analyzed such accumulation mechanisms as the facies state, direction, power of petroleum migration, the conditions of trap, the accumulation, leakage and reservation of petroleum, and the distribution rule of petroleum. The author also provides explanation for such practical problems the existence of a lot of mantle-derived CO_2, and its heterogeneous distribution on plane. By study on and recognition for chimney structure, the existence and distribution of much mantle-derived CO_2 found in this area are explained. Caused by tectonic thermal activities, the deep magma with much CO_2-bearing thermal fluid migrate upward along deep fault and chimney structures, which makes two wells within relatively short distance different gas composition, such as in well LF-1 and well LS36-1-1. Meanwhile, the author predicted the distribution of petroleum accumulation belt in middle-shallow layer for this area, pointed out the three favorable exploration areas in future, and provided the scientific and deciding references for future study on the commingling-genetic accumulation of petroleum in middle-deep layer and the new energy-gas hydrate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Anduo area is located in the Central Tibet, the middle segment of the Bangonghu-Nujiang suture. Anduo Block is the northern part of Lhasa terrane. The relationships among the different geological bodies were determined during the 1: 250000 regional geological surveying. Petrography, petrologic geochemistry, isotopic geochemistry and geochronology of igneous rocks from the suture and granitoids from Anduo Block were analyzed systematically as a whole for the first time. Then, their tectonic setting and history are discussed.Anduo ophiolitic melange consists of metamorphic peridotites, cumulates, plagiogranites, sheeted dykes swarm, pillow lava and radiolarian cherts. The concentration of Cr and Ni in the metamorphic peridotites is very high, with Mg# about 0.94 ~ 0.97, higher 87Sr/86Sr and Pb isotopic ratios, and lower 143Nd/i44Nd ratio. LREE is enriched relative to HREE and positive Eu anomaly is very clear. The REE distribution curve is U shape. Nb and Ta anomalies from cumulate gabbro and sheeted dyke swarm are not clear, while that are slightly negative from pillow lava. Plagiogranite belongs to strong calc-alkaline series with high Si, middle Al, low Fe, Mg and low K contents. Eu anomaly (~ 1.23) from plagiogranites is slightly positive. The character of all components of ophiolite is similar to that of the MORB, while to some extent the ophiolite was influenced by crustal material. Anduo ophiolite formed in a mature back-arc basin. Additionally, intermediate acidity volcanic rocks within Anduo phiolite melange are island arc calc-alkline rocks related to ocean subduction.The early-middle Jurassic plutonic rocks are tonalite, granodiorite bearing-phenocryst, magaporphyritic hornblende monzogranite, magaporphyritic monzogranite, monzogranite bearing-phenocryst and syenogranite in turn. They belong to calc-alkaline series which developed from middle K to high K series temporally. REE distribution curves of all plutonic rocks are similar and parallel to each other. SREE and negative Eu anomaly values decrease. In the multi-element spider diagram, the curves of different plutons are similar to each other, but troughs of Nb, Sr, P and Ti from young plutons become more evident. This suggests that thereare some closely petrogenetic affinities among plutonic rocks which make up amagma plutonism cycle of the early-middle Jurassic. Magma source is mainly crustal,but abundant mafic microgranular enclaves within granitoids indicate that crastalmagma should be mixed with mantle-derived magma and the mantle-derived magmadecreased subsequently. Tonalite has features of I-type granite, magaporphyriticmonzogranite is transition type, and monzogranite bearing-phenocryst is S-typegranite. The characteristic of granitoids from Anduo Block suggest that the formingtectonic setting is active continental margin.Reliable zircon U-Pb SHRIMP ages are obtained in the study area firstly. Plagiogranite from the Anduo ophiolite of the Bangonghu-Nujiang suture is 175.1 Ma, and granitoids from Anduo Block is 172.6-185.4 Ma. Additionally, plagioclase from the plagiogranite dates a 40Ar/39Ar age of 144 Ma, while biotite and hornblend from granitoids of Anduo Block give a 163-165 Ma.Similar cooling ages of plagiogranite from the Anduo ophiolitic melange and granitoids from Anduo Block and the spatial distribution of the ophiolitic rocks between Anduo, Naqu, and Shainzha area suggest that bilateral subduction of the Bangonghu-Nujiang oceanic basin took place in the early-middle Jurassic. During this subduction, Anduo ophiolitic rocks were related to north subduction of the Bangonghu-Nujiang oceanic basin and Anduo back-arc basin spreading, while granitoids from Anduo Block were related to south subduction.