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煤层气 2

自适应控制 2

跟踪 2

轨迹跟踪 2

DPP）；分布式功率转换器；开关电容转换器 1

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仿射编队；固定翼无人机；多智能体系统 1

传感器调度；区域检测；目标跟踪；道路约束；多普勒盲区 1

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An adaptive sliding mode control technology for weld seam tracking

Jie LIU,Youmin HU,Bo WU,Kaibo ZHOU,Mingfeng GE

《机械工程前沿（英文）》 2015年 第10卷 第1期   页码 95-101 doi: 10.1007/s11465-015-0332-3

摘要：

A novel adaptive sliding mode control algorithm is derived to deal with seam tracking control problem of welding robotic manipulator, during the process of large-scale structure component welding. The proposed algorithm does not require the precise dynamic model, and is more practical. Its robustness is verified by the Lyapunov stability theory. The analytical results show that the proposed algorithm enables better high-precision tracking performance with chattering-free than traditional sliding mode control algorithm under various disturbances.

关键词： weld seam tracking     welding robotic manipulator     adaptive control     sliding mode control    

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A review on transport of coal seam gas and its impact on coalbed methane recovery

Geoff G.X. WANG, Xiaodong ZHANG, Xiaorong WEI, Xuehai FU, Bo JIANG, Yong QIN

《化学科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 139-161 doi: 10.1007/s11705-010-0527-4

摘要： This paper presents a summary review on mass transport of coal seam gas (CSG) in coal associated with the coalbed methane (CBM) and CO geo-sequestration enhanced CBM (CO -ECBM) recovery and current research advances in order to provide general knowledge and fundamental understanding of the CBM/ECBM processes for improved CBM recovery. It will discuss the major aspects of theory and technology for evaluation and development of CBM resources, including the gas storage and flow mechanism in CBM reservoirs in terms of their differences with conventional natural gas reservoirs, and their impact on CBM production behavior. The paper summarizes the evaluation procedure and methodologies used for CBM exploration and exploitation with some recommendations.

关键词： mass transport     coal seam gas (CSG)     coalbed methane (CBM)     coal     CBM recovery     carbon dioxide storage    

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Study of mechanism of activating flux increasing weld penetration of AC A-TIG welding for aluminum alloy

HUANG Yong, FAN Ding, FAN Qinghua

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 442-447 doi: 10.1007/s11465-007-0076-9

摘要： When multi-component flux AF305 is used as surface activating flux for an aluminum alloy, the weld pene tration of activating flux-tungsten inert-gas (A-TIG) welding is over two times more than that of conventional TIG welding. Using A-TIG welding with the modes of alternating current (AC), direct current electrode negative (DCEN) and direct current electrode positive (DCEP), respectively, the flux differently affects weld penetration when the polarity is different. After studied the effect of compelled arc con striction on weld penetration of AC welding, it is believed that the constriction of the whole arc root is not the main mechanism that flux AF305 dramatically improves weld penetration. The penetration has a relationship with the separate distribution of slag on the weld surface. Then, an observation of scanning electron microscopy (SEM) and an electronic data systems (EDS) analysis of slag were performed respectively. The separate distribution of slag on the weld pool during welding and the great constriction of arc spots were confirmed by TIG welding with helium shielding gas. The relationship between slag distribution and weld penetration was studied by adding aluminum powder into flux AF305 to change the distribution of slag. During welding, the separate distribution of slag on the weld pool results in the great constriction of arc spots, an increase in arc spot force, and an increase in Lorentz force within the arc and weld pool. Finally, the weld penetration is increased.

关键词： A-TIG welding     surface     DCEN     electrode negative     increase    

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Local fracture properties and dissimilar weld integrity in nuclear power plants

Guozhen WANG, Haitao WANG, Fuzhen XUAN, Shantung TU, Changjun LIU

《机械工程前沿（英文）》 2013年 第8卷 第3期   页码 283-290 doi: 10.1007/s11465-013-0250-1

摘要：

In this paper, the local fracture properties in a Alloy52M dissimilar metal welded joint (DMWJ) between A508 ferritic steel and 316 L stainless steel in nuclear power plants were investigated by using the single-edge notched bend (SENB) specimens, and their use in integrity assessment of DMWJ structures was analyzed. The results show that the local fracture resistance in the DMWJ is determined by local fracture mechanism, and which is mainly related to the microstructures and local strength mismatches of materials at the crack locations. The initial cracks always grow towards the materials with lower strength, and the crack path deviation is mainly controlled by the local strength mismatch. If the local fracture properties could not be used for cracks in the heat affected zones (HAZs), interface and near interface zones, the use of the fracture properties ( -resistance curves) of base metals or weld metals following present codes will unavoidably produce non-conservative (unsafe) or excessive conservative assessment results. In most cases, the assessment results will be potentially unsafe. Therefore, it is recommended to obtain and use local mechanical and fracture properties in the integrity assessment of DMWJs.

关键词： local fracture properties     dissimilar metal welded joint     integrity assessment     strength mismatch     crack growth path    

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急倾斜煤层开采对地表构筑物影响的预计

高明中,王列平

《中国工程科学》 2007年 第9卷 第11期   页码 142-146

摘要：

针对淮南某矿急倾斜煤层开采复杂的采矿地质条件，运用概率积分法对优化后的开采方案所引起 的地表沉陷进行研究，总结出急倾斜煤层开采重复采动所引起的厚冲积层地表沉陷的相关参数。所得结果 对现场开采及地表沉陷治理具有一定的指导作用，对于同类地质和开采条件的矿区具有重要参考价值。

关键词： 急倾斜煤层     地表移动与变形     概率积分法     预计    

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Output tracking control of mobile manipulators based on dynamical sliding-mode control

WUYuxiang, FENG Ying, HU Yueming

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 110-115 doi: 10.1007/s11465-007-0019-5

摘要： A dynamical sliding-mode controller is devised to track the output of mobile manipulators. During the investigation, firstly a reduced dynamic model considering the dynamics of the driving motor is developed for mobile manipulators. Then, the system is decomposed into four lower-dimensional subsystems by means of diffeomorphism and nonlinear input transformation. Moreover, a design method of the dynamical sliding-mode controller that is applied to the output tracking of mobile manipulators is proposed. The simulation results indicate that the dynamical sliding-mode controller can not only track the given trajectory correctly but also reduce the chattering of sliding-mode control system considerably.

关键词： lower-dimensional     nonlinear     trajectory     tracking     diffeomorphism    

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煤层注水参数的数量化理论正交设计优化法的研究

秦书玉,秦伟瀚

《中国工程科学》 2003年 第5卷 第10期   页码 52-55

摘要：

应用正交设计优化煤层注水工艺参数的组合，对地质条件稳定的煤层是实现最佳注水效果的一种较好的方法。但是，对于地质条件不断变化的煤层，采用该方法，其效果不一定能满足注水工程要求。为此，针对地质因素为不稳定状态下的煤层及影响煤层注水的地质因素既有定性变量又有定量变量的特征，提出利用数量化理论与正交设计2种方法确定注水工艺参数的最优组合，并进行了工程试验优化研究。试验结果表明，此法节省注水试验工程量，接近实际工程要求。

关键词： 数量化理论     工艺参数     正交设计     煤层注水     试验研究    

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开采煤层顶板环形裂隙圈内走向长钻孔法抽放瓦斯研究

刘泽功,袁亮,戴广龙,石必明,卢平,涂敏

《中国工程科学》 2004年 第6卷 第5期   页码 32-38

摘要：

开采煤层工作面的瓦斯主要来源于该煤层、采空区和邻近层的卸压解吸瓦斯。由于煤层松软，顺层钻孔施工难，不便钻孔抽放瓦斯。若对采空区实施大面积抽放，工程难度大，而且抽不出高浓度瓦斯。因此，寻找瓦斯运移的裂隙通道和瓦斯富集区，实施有效的瓦斯抽放工程是实现高效瓦斯抽放的技术关键。采用实验室相似材料试验、数值模拟计算和工业性试验研究方法，研究寻找采场上覆岩层中环形裂隙圈形成机理和位置，把抽放钻孔布置在环形裂隙圈内，进行“环形裂隙圈内走向长钻孔法”瓦斯抽放。这种瓦斯抽放技术使低透气性高瓦斯煤层的开采和瓦斯抽放分层区进行，在开采层工作面采煤，在顶板层裂隙区抽放卸压瓦斯，对流向工作面上隅角的瓦斯起到了截流作用，解决了松软低透气性高瓦斯煤层群开采瓦斯抽放困难的关键技术难题。该瓦斯抽放技术在淮南矿区高瓦斯工作面的应用结果表明，采煤工作面瓦斯抽放率达到60%以上，实现煤层群首采煤层安全、高效、集约化开采。

关键词： 煤层顶板     相似材料试验     数值计算     环形裂隙圈     瓦斯抽放    

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Dynamic Target Tracking of Unmanned Aerial Vehicles Under Unpredictable Disturbances

Yanjie Chen,Yangning Wu,Limin Lan,Hang Zhong,Zhiqiang Miao,Hui Zhang,Yaonan Wang,

《工程（英文）》 doi: 10.1016/j.eng.2023.05.017

摘要： This study proposes an image-based visual servoing (IBVS) method based on a velocity observer for an unmanned aerial vehicle (UAV) for tracking a dynamic target in Global Positioning System (GPS)-denied environments. The proposed method derives the simplified and decoupled image dynamics of underactuated UAVs using a constructed virtual camera and then considers the uncertainties caused by the unpredictable rotations and velocities of the dynamic target. A novel image depth model that extends the IBVS method to track a rotating target with arbitrary orientations is proposed. The depth model ensures image feature accuracy and image trajectory smoothness in rotating target tracking. The relative velocities of the UAV and the dynamic target are estimated using the proposed velocity observer. Thanks to the velocity observer, translational velocity measurements are not required, and the control chatter caused by noise-containing measurements is mitigated. An integral-based filter is proposed to compensate for unpredictable environmental disturbances in order to improve the anti-disturbance ability. The stability of the velocity observer and IBVS controller is analyzed using the Lyapunov method. Comparative simulations and multistage experiments are conducted to illustrate the tracking stability, anti-disturbance ability, and tracking robustness of the proposed method with a dynamic rotating target.

关键词： Unmanned aerial vehicle     Visual servoing     Velocity observer     Target tracking    

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Wheel tracking methods to evaluate moisture sensitivity of hot-mix asphalt mixtures

Jie HAN,Harihar Shiwakoti

《结构与土木工程前沿（英文）》 2016年 第10卷 第1期   页码 30-43 doi: 10.1007/s11709-016-0318-1

摘要： Existing test methods to determine moisture sensitivity in hot-mix asphalt (HMA) mixtures are time consuming and inconsistent. This research focused on wheel tracking devices to evaluate moisture sensitivity. The Asphalt Pavement Analyzer (APA) and the Hamburg Wheel Tracking Device (HWTD) were used for this research. Compacted cylindrical samples were fabricated using a Superpave Gyratory compactor. This study selected two most commonly used mixtures, SM-12.5A with PG 64-22 binder in overlay projects and SM-19A mixtures with PG 64-22 binder for major modification projects at Kansas Department of Transportation. Test results show that APA tests could induce stripping in most samples without any anti-stripping agent, which could be identified visually. However, APA results did not indicate any stripping inflection point while the HWTD results showed stripping inflection points, which are important to identify stripping potential of mixtures. The APA results show that wet tests are severe at lower temperatures. The HWTD results show improvement in the performance using anti-stripping agents at later stage. The HWTD test is more effective as a rapid test method in case of determining moisture sensitivity. Laboratory results from this study should be verified and correlated with field performance.

关键词： hot-mix asphalt     moisture sensitivity     rutting     wheel tracking test    

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Fractional order extremum seeking approach for maximum power point tracking of photovoltaic panels

Ammar NEÇAIBIA,Samir LADACI,Abdelfatah CHAREF,Jean Jacques LOISEAU

《能源前沿（英文）》 2015年 第9卷 第1期   页码 43-53 doi: 10.1007/s11708-014-0343-5

摘要： Due to the high interest in renewable energy and diversity of research regarding photovoltaic (PV) array, a great research effort is focusing nowadays on solar power generation and its performance improvement under various weather conditions. In this paper, an integrated framework was proposed, which achieved both maximum power point tracking (MPPT) and minimum ripple signals. The proposed control scheme was based on extremum-seeking (ES) combined with fractional order systems (FOS). This auto-tuning strategy was developed to maximize the PV panel output power through the regulation of the voltage input to the DC/DC converter in order to lead the PV system steady-state to a stable oscillation behavior around the maximum power point (MPP). It is shown that fractional order operators can improve the plant dynamics with respect to time response and disturbance rejection. The effectiveness of the proposed controller scheme is illustrated with simulations using measured solar radiation data.

关键词： extremum seeking (ES)     fractional order control (FOC)     fractional calculus     photovoltaic (PV) panel     maximum power point tracking (MPPT)    

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Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 595-608 doi: 10.1007/s11709-021-0720-1

摘要： The effective notch stress approach for evaluating the fatigue strength of rib–deck welds requires notch stress concentration factors obtained from complex finite element analysis. To improve the efficiency of the approach, the notch stress concentration factors for three typical fatigue-cracking modes (i.e., root–toe, root–deck, and toe–deck cracking modes) were thoroughly investigated in this study. First, we developed a model for investigating the effective notch stress in rib–deck welds. Then, we performed a parametric analysis to investigate the effects of multiple geometric parameters of a rib–deck weld on the notch stress concentration factors. On this basis, the multiple linear stepwise regression analysis was performed to obtain the optimal regression functions for predicting the notch stress concentration factors. Finally, we employed the proposed formulas in a case study. The notch stress concentration factors estimated from the developed formulas show agree well with the finite element analysis results. The results of the case study demonstrate the feasibility and reliability of the proposed formulas. It also shows that the fatigue design curve of FAT225 seems to be conservative for evaluating the fatigue strength of rib–deck welds.

关键词： notch stress concentration factor     rib–deck weld     parametric analysis     regression analysis     parametric equation    

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Time-varying formation tracking for uncertain second-order nonlinearmulti-agent systems

Mao-peng RAN, Li-hua XIE, Jun-cheng LI

《信息与电子工程前沿（英文）》 2019年 第20卷 第1期   页码 76-87 doi: 10.1631/FITEE.1800557

摘要：

Our study is concerned with the time-varying formation tracking problem for second-order multi-agent systems that are subject to unknown nonlinear dynamics and external disturbance, and the states of the followers form a predefined time-varying formation while tracking the state of the leader. The total uncertainty lumps the unknown nonlinear dynamics and the external disturbance, and is regarded as an extended state of the agent. To estimate the total uncertainty, we design an extended state observer (ESO). Then we propose a novel ESO based time-varying formation tracking protocol. It is proved that, under the proposed protocol, the ESO estimation error and the time-varying formation tracking error can be made arbitrarily small. An application to the target enclosing problem for multiple unmanned aerial vehicles (UAVs) verifies the effectiveness and superiority of the proposed approach.

关键词： Multi-agent system     Time-varying formation     Formation tracking     Nonlinear dynamics     Extended state observer (ESO)    

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Characteristics of metal magnetic memory signals of different steels under static tension

Yiliang ZHANG, Ruibin GOU, Jimin LI, Gongtian SHEN,

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 226-232 doi: 10.1007/s11465-010-0012-2

摘要： To study the characteristics of metal magnetic memory (MMM) signals of different steels during tensile test, static tension tests were applied to 30 pieces of Q235 and 16MnR base metal and welded specimens. During the various deformation periods, MMM signals are tested, and micrometallographic is observed. Furthermore, the derivative of magnetic intensity (d/d) is analyzed by mathematical and statistical methods to study the macro and micro corresponding relationships and difference among magnetic signals. Results show that despite the different magnetic intensity () curves of different materials, their d/d patterns in the yielding and necking stages are the same; welded specimens have the similar magnetic signal curves with their base metal, and the welded structure does not interfere with its distribution; different materials have their unique zero point (＝0) before being fractured, which is independent of the fracture location; there is a direct relationship between the intragranular slip and the changes of magnetic signals, which indicates the uneven plastic deformation.

关键词： metal magnetic memory (MMM)     magnetic intensity (Hp)     static tension     weld    

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浅埋深两硬条件下特厚煤层综放开采技术

张忠温,吴吉南

《中国工程科学》 2011年 第13卷 第11期   页码 107-112

摘要：

针对平朔矿区4号煤层条件，采用理论分析方法研究了浅埋深两硬条件下4号煤层顶煤的冒放性及合理采煤方法。以提高顶煤冒放性为目标，采用数值模拟的方法进行了综放工作面参数及设备选型配套研究。实践表明，浅埋深两硬煤层条件下通过加大综放工作面长度与割煤高度，可以实现安全、高效、高回收率开采。

关键词： 浅埋深     两硬煤层     顶煤冒放性     大采高综放    

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标题 作者 时间 类型 操作

An adaptive sliding mode control technology for weld seam tracking

Jie LIU,Youmin HU,Bo WU,Kaibo ZHOU,Mingfeng GE

期刊论文

A review on transport of coal seam gas and its impact on coalbed methane recovery

Geoff G.X. WANG, Xiaodong ZHANG, Xiaorong WEI, Xuehai FU, Bo JIANG, Yong QIN

期刊论文

Study of mechanism of activating flux increasing weld penetration of AC A-TIG welding for aluminum alloy

HUANG Yong, FAN Ding, FAN Qinghua

期刊论文

Local fracture properties and dissimilar weld integrity in nuclear power plants

Guozhen WANG, Haitao WANG, Fuzhen XUAN, Shantung TU, Changjun LIU

期刊论文

急倾斜煤层开采对地表构筑物影响的预计

高明中,王列平

期刊论文

Output tracking control of mobile manipulators based on dynamical sliding-mode control

WUYuxiang, FENG Ying, HU Yueming

期刊论文

煤层注水参数的数量化理论正交设计优化法的研究

秦书玉,秦伟瀚

期刊论文

开采煤层顶板环形裂隙圈内走向长钻孔法抽放瓦斯研究

刘泽功,袁亮,戴广龙,石必明,卢平,涂敏

期刊论文

Dynamic Target Tracking of Unmanned Aerial Vehicles Under Unpredictable Disturbances

Yanjie Chen,Yangning Wu,Limin Lan,Hang Zhong,Zhiqiang Miao,Hui Zhang,Yaonan Wang,

期刊论文

Wheel tracking methods to evaluate moisture sensitivity of hot-mix asphalt mixtures

Jie HAN,Harihar Shiwakoti

期刊论文

Fractional order extremum seeking approach for maximum power point tracking of photovoltaic panels

Ammar NEÇAIBIA,Samir LADACI,Abdelfatah CHAREF,Jean Jacques LOISEAU

期刊论文

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

期刊论文

Time-varying formation tracking for uncertain second-order nonlinearmulti-agent systems

Mao-peng RAN, Li-hua XIE, Jun-cheng LI

期刊论文

Characteristics of metal magnetic memory signals of different steels under static tension

Yiliang ZHANG, Ruibin GOU, Jimin LI, Gongtian SHEN,

期刊论文

浅埋深两硬条件下特厚煤层综放开采技术

张忠温,吴吉南

期刊论文