Influences of inspecting time-interval and location on varying behavior of metal magnetic memory (MMM) signals of defects were studied. Different areas in two precracked weldments were inspected at different time-inte...Influences of inspecting time-interval and location on varying behavior of metal magnetic memory (MMM) signals of defects were studied. Different areas in two precracked weldments were inspected at different time-intervals by type TSC-1M-4 stress-concentration magnetic inspector to obtain MMM signals. Mechanisms of MMM signals varying behavior with inspecting time and space were analyzed and discussed respectively. It is found that MMM signals don't change with inspecting time-interval, since stress field and magnetic leakage field maintain unchanged at any time after welding. On the other hand, MMM signals differ greatly for different inspecting locations, because stress field and magnetic leakage field are unevenly distributed in defective ferromagnetic materials.展开更多
In the aviation industry,cable bracket is one of the most common parts.The traditional assembly state inspection method of cable bracket is to manually compare by viewing 3 D models.The purpose of this paper is to add...In the aviation industry,cable bracket is one of the most common parts.The traditional assembly state inspection method of cable bracket is to manually compare by viewing 3 D models.The purpose of this paper is to address the problem of inefficiency of traditional inspection method.In order to solve the problem that machine learning algorithm requires large dataset and manually labeling of dataset is a laborious and time-consuming task,a simulation platform is developed to automatically generate synthetic realistic brackets images with pixel-level annotations based on 3 D digital mock-up.In order to obtain accurate shapes of brackets from 2 D image,a brackets recognizer based on Mask R-CNN is trained.In addition,a semi-automatic cable bracket inspection method is proposed.With this method,the inspector can easily obtain the inspection result only by taking a picture with a portable device,such as augmented reality(AR)glasses.The inspection task will be automatically executed via bracket recognition and matching.The experimental result shows that the proposed method for automatically labeling dataset is valid and the proposed cable bracket inspection method can effectively inspect cable bracket in the aircraft.Finally,a prototype system based on client-server framework has been developed for validation purpose.展开更多
With the development of wood industry, the processing of wood products becomemore significant. This paper discusses the developmen of machine vision system used to inspect andclassny the various types of defects of wo...With the development of wood industry, the processing of wood products becomemore significant. This paper discusses the developmen of machine vision system used to inspect andclassny the various types of defects of wood suxface. The surface defeds means the variations ofcolour and textUre. The machine vision system is to dated undesirable 'defecs' that can appear onthe surface of rough wood lwnber. A neural network was used within the Blackboard framework fora labeling verification step of the high-level recognition module of vision system. The system hasbere successfully tested on a number of boards from several different species.展开更多
A photoelectric equipment for inspecting artillery bore is composed of digital display grating sensor and data processing with computer.It can replace the traditional mechanical measurer and realize the automatic insp...A photoelectric equipment for inspecting artillery bore is composed of digital display grating sensor and data processing with computer.It can replace the traditional mechanical measurer and realize the automatic inspection of artillery bore.Introduced are briefly the working principles and analysis of this device.展开更多
The electric generator is a highly stressed plant component requiring periodic inspection and maintenance to reduce the risk of a costly forced outage. This paper briefly introduces two new robotic technologies for pe...The electric generator is a highly stressed plant component requiring periodic inspection and maintenance to reduce the risk of a costly forced outage. This paper briefly introduces two new robotic technologies for performing fast and reliable inspections of two pole electric generators with minimal mechanical disassembly requirements. The first robotic system is designed to inspect within the generator rotor and stator air gap, while the second robotic system is designed to inspect the generator retaining rings. An overview of the design and construction of each system is provided, along with an explanation of the capabilities and benefits they bring to the power station owner.展开更多
According to the operation characteristics of autoclave, the possible defects are analyzed by damage modes, the inspection methods are selected contrapuntally, and the causes of the defects affecting the safe operatio...According to the operation characteristics of autoclave, the possible defects are analyzed by damage modes, the inspection methods are selected contrapuntally, and the causes of the defects affecting the safe operation of the equipment are analyzed. This study effectively improves the quality of inspection work and plays an important role in strengthening the management of equipment use and reducing accidents.展开更多
Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined sp...Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined spaces,and millimeter-scale height restrictions,presenting significant challenges to conventional inspection methods.Here,we present an ultrasonic microrobot(weight,80 mg;dimensions,24 mm×7 mm;thickness,210μm)to realize agile and bidirectional navigation in narrow pipelines.The ultrathin structural design of the robot is achieved through a high-performance piezoelectric composite film microstructure based on MEMS technology.The robot exhibits various vibration modes when driven by ultrasonic frequency signals,its motion speed reaches81 cm s-1 at 54.8 k Hz,exceeding that of the fastest piezoelectric microrobots,and its forward and backward motion direction is controllable through frequency modulation,while the minimum driving voltage for initial movement can be as low as 3 VP-P.Additionally,the robot can effortlessly climb slopes up to 24.25°and carry loads more than 36 times its weight.The robot is capable of agile navigation through curved L-shaped pipes,pipes made of various materials(acrylic,stainless steel,and polyvinyl chloride),and even over water.To further demonstrate its inspection capabilities,a micro-endoscope camera is integrated into the robot,enabling real-time image capture inside glass pipes.展开更多
In this paper, it is presented that an approach based on Continuous Wavelet Thansform(CWT) and Fourier Transform(FT) for identifying ultrasonic echoes in inspecting oil well cementing quality. First, CWT is used to pr...In this paper, it is presented that an approach based on Continuous Wavelet Thansform(CWT) and Fourier Transform(FT) for identifying ultrasonic echoes in inspecting oil well cementing quality. First, CWT is used to process echo signals. Then spectra of the processing results in some specilic scale-time segments are calculated as pattern features. The research results show that theoretical calculations basically agree with experimental results. Compared with the aPproach based on the spectra or Discrete Wavlet Transform, our approach has advantages of fine analyzing scales, stable features and high recognizing rate. It is very suitable to identify echo signals whose spectra vary with time.展开更多
Many heat transfer tubes are distributed on the tube plates of a steam generator that requires periodic inspection by robots.Existing inspection robots are usually involved in issues:Robots with manipulators need comp...Many heat transfer tubes are distributed on the tube plates of a steam generator that requires periodic inspection by robots.Existing inspection robots are usually involved in issues:Robots with manipulators need complicated installation due to their fixed base;tube mobile robots suffer from low running efficiency because of their structural restricts.Since there are thousands of tubes to be checked,task planning is essential to guarantee the precise,orderly,and efficient inspection process.Most in-service robots check the task tubes using row-by-row and column-bycolumn planning.This leads to unnecessary inspections,resulting in a long shutdown and affecting the regular operation of a nuclear power plant.Therefore,this paper introduces the structure and control system of a dexterous robot and proposes a task planning method.This method proceeds into three steps:task allocation,base position search,and sequence planning.To allocate the task regions,this method calculates the tool work matrix and proposes a criterion to evaluate a sub-region.And then all tasks contained in the sub-region are considered globally to search the base positions.Lastly,we apply an improved ant colony algorithm for base sequence planning and determine the inspection orders according to the planned path.We validated the optimized algorithm by conducting task planning experiments using our robot on a tube sheet.The results show that the proposed method can accomplish full task coverage with few repetitive or redundant inspections and it increases the efficiency by 33.31% compared to the traditional planning algorithms.展开更多
Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,an...Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.展开更多
In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and...In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.展开更多
To improve the efficiency and accuracy of path planning for fan inspection tasks in thermal power plants,this paper proposes an intelligent inspection robot path planning scheme based on an improved A^(*)algorithm.The...To improve the efficiency and accuracy of path planning for fan inspection tasks in thermal power plants,this paper proposes an intelligent inspection robot path planning scheme based on an improved A^(*)algorithm.The inspection robot utilizes multiple sensors to monitor key parameters of the fans,such as vibration,noise,and bearing temperature,and upload the data to the monitoring center.The robot’s inspection path employs the improved A^(*)algorithm,incorporating obstacle penalty terms,path reconstruction,and smoothing optimization techniques,thereby achieving optimal path planning for the inspection robot in complex environments.Simulation results demonstrate that the improved A^(*)algorithm significantly outperforms the traditional A^(*)algorithm in terms of total path distance,smoothness,and detour rate,effectively improving the execution efficiency of inspection tasks.展开更多
1.C.Li,"Holding‘China Inc.’Together:The CCP and The Rise of China’s Yangqi",The China Quarterly,Vol.228,2016,pp.927-949.2.J.Gao,"‘Bypass the Lying Mouths’:How Does the CCP Tackle Information Distor...1.C.Li,"Holding‘China Inc.’Together:The CCP and The Rise of China’s Yangqi",The China Quarterly,Vol.228,2016,pp.927-949.2.J.Gao,"‘Bypass the Lying Mouths’:How Does the CCP Tackle Information Distortion at Local Levels?",The China Quarterly,Vol.228,2016,pp.950-969.3.C.Sorace,"Party Spirit Made Flesh:The Production of Legitimacy in the Aftermath of the 2008Sichuan Earthquake",The China Journal,Vol.76,2016,pp.41-62.4.Y.Yeo,"Complementing the Local Discipline Inspection Commissions of the CCP:Empowerment of the Central Inspection Groups",Journal of Contemporary China,Vol.25,No.97,2016,pp.59-74.展开更多
The China comprehensive inspection train(CIT)is designed for evaluating railway infrastructure to ensure safe railway operations.The CIT integrates an array of inspection devices,capable of simultaneously assessing ra...The China comprehensive inspection train(CIT)is designed for evaluating railway infrastructure to ensure safe railway operations.The CIT integrates an array of inspection devices,capable of simultaneously assessing railway health condition parameters.The CIT450,representing the second generation,can reach a top speed of 450 km/h with inspection on the infrastructure.This paper begins by outlining the global evolution of inspection trains.It then focuses on the critical technologies underlying the CIT450,which include:(1)real-time inspection data acquisition with spatial and temporal synchronization;(2)intelligent fusion and centralized management of multi-source inspection data,enabling remote supervision of the inspection process;(3)technologies in inspecting track,train–track interaction,catenary,signalling systems,and train operating environment;and(4)AI-driven analysis and correlation of inspection data.The future developmental directions for comprehensive inspection trains are discussed finally.The CIT450’s approach to real-time railway health monitoring can enrich traditional inspection means,operational,and maintenance methods by enhancing inspection efficiency and automating railway maintenance.展开更多
Aims and Scope Asian Journal of Social Pharmacy(AJSP)is peer-reviewed quarterly English journal jointly hosted by Herbal Font Pharmaceutical Limited and Shenyang Pharmaceutical University.AJSP is dedicated to providin...Aims and Scope Asian Journal of Social Pharmacy(AJSP)is peer-reviewed quarterly English journal jointly hosted by Herbal Font Pharmaceutical Limited and Shenyang Pharmaceutical University.AJSP is dedicated to providing researchers,pharmacists,administrators,and educators working within the field of pharmacy worldwide with a platform of communication in the advancement and development in social pharmacy.The journal welcomes original contributions in pharmacy-related research including policies,regulations and laws,administration,monitoring,inspection,surveillance,utilization,formulary analysis,drug manufacturing,drug marketing,drug R&D,pharmacy practice,clinical pharmacy,pharmacoeconomics,and modernization of traditional Chinese medicine.To expedite the dissemination of findings from latest research,the journal receives rapid research report.Rapid research reports can be published within 3 months on submission,which does not preclude publication of full length reports of the research work in other journals.展开更多
Precision steel balls are critical components in precision bearings.Surface defects on the steel balls will significantly reduce their useful life and cause linear or rotational transmission errors.Human visual inspec...Precision steel balls are critical components in precision bearings.Surface defects on the steel balls will significantly reduce their useful life and cause linear or rotational transmission errors.Human visual inspection of precision steel balls demands significant labor work.Besides,human inspection cannot maintain consistent quality assurance.To address these limitations and reduce inspection time,a convolutional neural network(CNN)based optical inspection system has been developed that automatically detects steel ball defects using a novel designated vertical mechanism.During image detection processing,two key challenges were addressed and resolved.They are the reflection caused by the coaxial light onto the ball center and the image deformation appearing at the edge of the steel balls.The special vertical rotating mechanism utilizing a spinning rod along with a spiral track was developed to enable successful and reliable full steel ball surface inspection during the rod rotation.The combination of the spinning rod and the spiral rotating component effectively rotates the steel ball to facilitate capturing complete surface images.Geometric calculations demonstrate that the steel balls can be completely inspected through specific rotation degrees,with the surface fully captured in 12 photo shots.These images are then analyzed by a CNN to determine surface quality defects.This study presents a new inspection method that enables the entire examination of steel ball surfaces.The successful development of this innovative automated optical inspection system with CNN represents a significant advancement in inspection quality control for precision steel balls.展开更多
This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-coo...This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-cooperative target with active maneuverability in front lighting.First,the impulsive orbital game problem is formulated as a turn-based sequential game problem.Second,several typical relative orbit transfers are encapsulated into modules to construct a parameterized action space containing discrete modules and continuous parameters,and multi-pass deep Q-networks(MPDQN)algorithm is used to implement autonomous decision-making.Then,a curriculum learning method is used to gradually increase the difficulty of the training scenario.The backtracking proportional self-play training framework is used to enhance the agent’s ability to defeat inconsistent strategies by building a pool of opponents.The behavior variations of the agents during training indicate that the intelligent game system gradually evolves towards an equilibrium situation.The restraint relations between the agents show that the agents steadily improve the strategy.The influence of various factors on game results is tested.展开更多
Reticular structures are the basis of major infrastructure projects,including bridges,electrical pylons and airports.However,inspecting and maintaining these structures is both expensive and hazardous,traditionally re...Reticular structures are the basis of major infrastructure projects,including bridges,electrical pylons and airports.However,inspecting and maintaining these structures is both expensive and hazardous,traditionally requiring human involvement.While some research has been conducted in this field of study,most efforts focus on faults identification through images or the design of robotic platforms,often neglecting the autonomous navigation of robots through the structure.This study addresses this limitation by proposing methods to detect navigable surfaces in truss structures,thereby enhancing the autonomous capabilities of climbing robots to navigate through these environments.The paper proposes multiple approaches for the binary segmentation between navigable surfaces and background from 3D point clouds captured from metallic trusses.Approaches can be classified into two paradigms:analytical algorithms and deep learning methods.Within the analytical approach,an ad hoc algorithm is developed for segmenting the structures,leveraging different techniques to evaluate the eigendecomposition of planar patches within the point cloud.In parallel,widely used and advanced deep learning models,including PointNet,PointNet++,MinkUNet34C,and PointTransformerV3,are trained and evaluated for the same task.A comparative analysis of these paradigms reveals some key insights.The analytical algorithm demonstrates easier parameter adjustment and comparable performance to that of the deep learning models,despite the latter’s higher computational demands.Nevertheless,the deep learning models stand out in segmentation accuracy,with PointTransformerV3 achieving impressive results,such as a Mean Intersection Over Union(mIoU)of approximately 97%.This study highlights the potential of analytical and deep learning approaches to improve the autonomous navigation of climbing robots in complex truss structures.The findings underscore the trade-offs between computational efficiency and segmentation performance,offering valuable insights for future research and practical applications in autonomous infrastructure maintenance and inspection.展开更多
基金Project(50475113) supported by the National Natural Science Foundation of ChinaProject(20030056002) supported by Specialized Research Fund for Doctoral Program of Higher Education, China
文摘Influences of inspecting time-interval and location on varying behavior of metal magnetic memory (MMM) signals of defects were studied. Different areas in two precracked weldments were inspected at different time-intervals by type TSC-1M-4 stress-concentration magnetic inspector to obtain MMM signals. Mechanisms of MMM signals varying behavior with inspecting time and space were analyzed and discussed respectively. It is found that MMM signals don't change with inspecting time-interval, since stress field and magnetic leakage field maintain unchanged at any time after welding. On the other hand, MMM signals differ greatly for different inspecting locations, because stress field and magnetic leakage field are unevenly distributed in defective ferromagnetic materials.
基金supported by the Civil Airplane Technology Development Program。
文摘In the aviation industry,cable bracket is one of the most common parts.The traditional assembly state inspection method of cable bracket is to manually compare by viewing 3 D models.The purpose of this paper is to address the problem of inefficiency of traditional inspection method.In order to solve the problem that machine learning algorithm requires large dataset and manually labeling of dataset is a laborious and time-consuming task,a simulation platform is developed to automatically generate synthetic realistic brackets images with pixel-level annotations based on 3 D digital mock-up.In order to obtain accurate shapes of brackets from 2 D image,a brackets recognizer based on Mask R-CNN is trained.In addition,a semi-automatic cable bracket inspection method is proposed.With this method,the inspector can easily obtain the inspection result only by taking a picture with a portable device,such as augmented reality(AR)glasses.The inspection task will be automatically executed via bracket recognition and matching.The experimental result shows that the proposed method for automatically labeling dataset is valid and the proposed cable bracket inspection method can effectively inspect cable bracket in the aircraft.Finally,a prototype system based on client-server framework has been developed for validation purpose.
文摘With the development of wood industry, the processing of wood products becomemore significant. This paper discusses the developmen of machine vision system used to inspect andclassny the various types of defects of wood suxface. The surface defeds means the variations ofcolour and textUre. The machine vision system is to dated undesirable 'defecs' that can appear onthe surface of rough wood lwnber. A neural network was used within the Blackboard framework fora labeling verification step of the high-level recognition module of vision system. The system hasbere successfully tested on a number of boards from several different species.
文摘A photoelectric equipment for inspecting artillery bore is composed of digital display grating sensor and data processing with computer.It can replace the traditional mechanical measurer and realize the automatic inspection of artillery bore.Introduced are briefly the working principles and analysis of this device.
文摘The electric generator is a highly stressed plant component requiring periodic inspection and maintenance to reduce the risk of a costly forced outage. This paper briefly introduces two new robotic technologies for performing fast and reliable inspections of two pole electric generators with minimal mechanical disassembly requirements. The first robotic system is designed to inspect within the generator rotor and stator air gap, while the second robotic system is designed to inspect the generator retaining rings. An overview of the design and construction of each system is provided, along with an explanation of the capabilities and benefits they bring to the power station owner.
文摘According to the operation characteristics of autoclave, the possible defects are analyzed by damage modes, the inspection methods are selected contrapuntally, and the causes of the defects affecting the safe operation of the equipment are analyzed. This study effectively improves the quality of inspection work and plays an important role in strengthening the management of equipment use and reducing accidents.
基金supported by the National Key Research and Development Program of China(No.2024YFB3212901)National Natural Science Foundation of China(12072189)the Medicine and Engineering Interdisciplinary Research Fund of Shanghai Jiao Tong University(No.YG2025ZD05)。
文摘Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined spaces,and millimeter-scale height restrictions,presenting significant challenges to conventional inspection methods.Here,we present an ultrasonic microrobot(weight,80 mg;dimensions,24 mm×7 mm;thickness,210μm)to realize agile and bidirectional navigation in narrow pipelines.The ultrathin structural design of the robot is achieved through a high-performance piezoelectric composite film microstructure based on MEMS technology.The robot exhibits various vibration modes when driven by ultrasonic frequency signals,its motion speed reaches81 cm s-1 at 54.8 k Hz,exceeding that of the fastest piezoelectric microrobots,and its forward and backward motion direction is controllable through frequency modulation,while the minimum driving voltage for initial movement can be as low as 3 VP-P.Additionally,the robot can effortlessly climb slopes up to 24.25°and carry loads more than 36 times its weight.The robot is capable of agile navigation through curved L-shaped pipes,pipes made of various materials(acrylic,stainless steel,and polyvinyl chloride),and even over water.To further demonstrate its inspection capabilities,a micro-endoscope camera is integrated into the robot,enabling real-time image capture inside glass pipes.
文摘In this paper, it is presented that an approach based on Continuous Wavelet Thansform(CWT) and Fourier Transform(FT) for identifying ultrasonic echoes in inspecting oil well cementing quality. First, CWT is used to process echo signals. Then spectra of the processing results in some specilic scale-time segments are calculated as pattern features. The research results show that theoretical calculations basically agree with experimental results. Compared with the aPproach based on the spectra or Discrete Wavlet Transform, our approach has advantages of fine analyzing scales, stable features and high recognizing rate. It is very suitable to identify echo signals whose spectra vary with time.
基金supported by the National Natural Science Foundation of China(Grant No.U2013214)the Self-Planned Task of the State Key Laboratory of Robotics and System(HIT),China(Grant No.SKLRS202001A03).
文摘Many heat transfer tubes are distributed on the tube plates of a steam generator that requires periodic inspection by robots.Existing inspection robots are usually involved in issues:Robots with manipulators need complicated installation due to their fixed base;tube mobile robots suffer from low running efficiency because of their structural restricts.Since there are thousands of tubes to be checked,task planning is essential to guarantee the precise,orderly,and efficient inspection process.Most in-service robots check the task tubes using row-by-row and column-bycolumn planning.This leads to unnecessary inspections,resulting in a long shutdown and affecting the regular operation of a nuclear power plant.Therefore,this paper introduces the structure and control system of a dexterous robot and proposes a task planning method.This method proceeds into three steps:task allocation,base position search,and sequence planning.To allocate the task regions,this method calculates the tool work matrix and proposes a criterion to evaluate a sub-region.And then all tasks contained in the sub-region are considered globally to search the base positions.Lastly,we apply an improved ant colony algorithm for base sequence planning and determine the inspection orders according to the planned path.We validated the optimized algorithm by conducting task planning experiments using our robot on a tube sheet.The results show that the proposed method can accomplish full task coverage with few repetitive or redundant inspections and it increases the efficiency by 33.31% compared to the traditional planning algorithms.
文摘Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.
基金funded by National Natural Science Foundation of China(Grant Nos.52130504,52305577,and 52175509)the Key Research and Development Plan of Hubei Province(Grant No.2022BAA013)+4 种基金the Major Program(JD)of Hubei Province(Grant No.2023BAA008-2)the Interdisciplinary Research Program of Huazhong University of Science and Technology(2023JCYJ047)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2023PY003)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(Grant No.GZB20230244)the fellowship from the China Postdoctoral Science Foundation(2024M750995)。
文摘In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.
文摘To improve the efficiency and accuracy of path planning for fan inspection tasks in thermal power plants,this paper proposes an intelligent inspection robot path planning scheme based on an improved A^(*)algorithm.The inspection robot utilizes multiple sensors to monitor key parameters of the fans,such as vibration,noise,and bearing temperature,and upload the data to the monitoring center.The robot’s inspection path employs the improved A^(*)algorithm,incorporating obstacle penalty terms,path reconstruction,and smoothing optimization techniques,thereby achieving optimal path planning for the inspection robot in complex environments.Simulation results demonstrate that the improved A^(*)algorithm significantly outperforms the traditional A^(*)algorithm in terms of total path distance,smoothness,and detour rate,effectively improving the execution efficiency of inspection tasks.
文摘1.C.Li,"Holding‘China Inc.’Together:The CCP and The Rise of China’s Yangqi",The China Quarterly,Vol.228,2016,pp.927-949.2.J.Gao,"‘Bypass the Lying Mouths’:How Does the CCP Tackle Information Distortion at Local Levels?",The China Quarterly,Vol.228,2016,pp.950-969.3.C.Sorace,"Party Spirit Made Flesh:The Production of Legitimacy in the Aftermath of the 2008Sichuan Earthquake",The China Journal,Vol.76,2016,pp.41-62.4.Y.Yeo,"Complementing the Local Discipline Inspection Commissions of the CCP:Empowerment of the Central Inspection Groups",Journal of Contemporary China,Vol.25,No.97,2016,pp.59-74.
基金supported by the National Natural Science Foundation of China(Grant No.52272427)the Technology Research and Development Program of China National Railway Group(Grant No.K2021T015)Development Plan of China Academy of Railway Sciences Corporation Ltd.(Grant No.2022YJ256)。
文摘The China comprehensive inspection train(CIT)is designed for evaluating railway infrastructure to ensure safe railway operations.The CIT integrates an array of inspection devices,capable of simultaneously assessing railway health condition parameters.The CIT450,representing the second generation,can reach a top speed of 450 km/h with inspection on the infrastructure.This paper begins by outlining the global evolution of inspection trains.It then focuses on the critical technologies underlying the CIT450,which include:(1)real-time inspection data acquisition with spatial and temporal synchronization;(2)intelligent fusion and centralized management of multi-source inspection data,enabling remote supervision of the inspection process;(3)technologies in inspecting track,train–track interaction,catenary,signalling systems,and train operating environment;and(4)AI-driven analysis and correlation of inspection data.The future developmental directions for comprehensive inspection trains are discussed finally.The CIT450’s approach to real-time railway health monitoring can enrich traditional inspection means,operational,and maintenance methods by enhancing inspection efficiency and automating railway maintenance.
文摘Aims and Scope Asian Journal of Social Pharmacy(AJSP)is peer-reviewed quarterly English journal jointly hosted by Herbal Font Pharmaceutical Limited and Shenyang Pharmaceutical University.AJSP is dedicated to providing researchers,pharmacists,administrators,and educators working within the field of pharmacy worldwide with a platform of communication in the advancement and development in social pharmacy.The journal welcomes original contributions in pharmacy-related research including policies,regulations and laws,administration,monitoring,inspection,surveillance,utilization,formulary analysis,drug manufacturing,drug marketing,drug R&D,pharmacy practice,clinical pharmacy,pharmacoeconomics,and modernization of traditional Chinese medicine.To expedite the dissemination of findings from latest research,the journal receives rapid research report.Rapid research reports can be published within 3 months on submission,which does not preclude publication of full length reports of the research work in other journals.
文摘Precision steel balls are critical components in precision bearings.Surface defects on the steel balls will significantly reduce their useful life and cause linear or rotational transmission errors.Human visual inspection of precision steel balls demands significant labor work.Besides,human inspection cannot maintain consistent quality assurance.To address these limitations and reduce inspection time,a convolutional neural network(CNN)based optical inspection system has been developed that automatically detects steel ball defects using a novel designated vertical mechanism.During image detection processing,two key challenges were addressed and resolved.They are the reflection caused by the coaxial light onto the ball center and the image deformation appearing at the edge of the steel balls.The special vertical rotating mechanism utilizing a spinning rod along with a spiral track was developed to enable successful and reliable full steel ball surface inspection during the rod rotation.The combination of the spinning rod and the spiral rotating component effectively rotates the steel ball to facilitate capturing complete surface images.Geometric calculations demonstrate that the steel balls can be completely inspected through specific rotation degrees,with the surface fully captured in 12 photo shots.These images are then analyzed by a CNN to determine surface quality defects.This study presents a new inspection method that enables the entire examination of steel ball surfaces.The successful development of this innovative automated optical inspection system with CNN represents a significant advancement in inspection quality control for precision steel balls.
文摘This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-cooperative target with active maneuverability in front lighting.First,the impulsive orbital game problem is formulated as a turn-based sequential game problem.Second,several typical relative orbit transfers are encapsulated into modules to construct a parameterized action space containing discrete modules and continuous parameters,and multi-pass deep Q-networks(MPDQN)algorithm is used to implement autonomous decision-making.Then,a curriculum learning method is used to gradually increase the difficulty of the training scenario.The backtracking proportional self-play training framework is used to enhance the agent’s ability to defeat inconsistent strategies by building a pool of opponents.The behavior variations of the agents during training indicate that the intelligent game system gradually evolves towards an equilibrium situation.The restraint relations between the agents show that the agents steadily improve the strategy.The influence of various factors on game results is tested.
基金funded by the spanish Ministry of Science,Innovation and Universities as part of the project PID2020-116418RB-I00 funded by MCIN/AEI/10.13039/501100011033.
文摘Reticular structures are the basis of major infrastructure projects,including bridges,electrical pylons and airports.However,inspecting and maintaining these structures is both expensive and hazardous,traditionally requiring human involvement.While some research has been conducted in this field of study,most efforts focus on faults identification through images or the design of robotic platforms,often neglecting the autonomous navigation of robots through the structure.This study addresses this limitation by proposing methods to detect navigable surfaces in truss structures,thereby enhancing the autonomous capabilities of climbing robots to navigate through these environments.The paper proposes multiple approaches for the binary segmentation between navigable surfaces and background from 3D point clouds captured from metallic trusses.Approaches can be classified into two paradigms:analytical algorithms and deep learning methods.Within the analytical approach,an ad hoc algorithm is developed for segmenting the structures,leveraging different techniques to evaluate the eigendecomposition of planar patches within the point cloud.In parallel,widely used and advanced deep learning models,including PointNet,PointNet++,MinkUNet34C,and PointTransformerV3,are trained and evaluated for the same task.A comparative analysis of these paradigms reveals some key insights.The analytical algorithm demonstrates easier parameter adjustment and comparable performance to that of the deep learning models,despite the latter’s higher computational demands.Nevertheless,the deep learning models stand out in segmentation accuracy,with PointTransformerV3 achieving impressive results,such as a Mean Intersection Over Union(mIoU)of approximately 97%.This study highlights the potential of analytical and deep learning approaches to improve the autonomous navigation of climbing robots in complex truss structures.The findings underscore the trade-offs between computational efficiency and segmentation performance,offering valuable insights for future research and practical applications in autonomous infrastructure maintenance and inspection.
