Parts with high-quality freeform surfaces have been widely used in industries,which require strict quality control during the manufacturing process.Among all the industrial inspection methods,contact measurement with ...Parts with high-quality freeform surfaces have been widely used in industries,which require strict quality control during the manufacturing process.Among all the industrial inspection methods,contact measurement with coordinate measuring machines or computer numerical control machine tool is a fundamental technique due to its high accuracy,robustness,and universality.In this paper,the existing research in the contact measurement field is systematically reviewed.First,different configurations of the measuring machines are introduced in detail,which may have influence on the corresponding sampling and inspection path generation criteria.Then,the entire inspection pipeline is divided into two stages,namely the pre-inspection and post-inspection stages.The typical methods of each sub-stage are systematically overviewed and classified,including sampling,accessibility analysis,inspection path generation,probe tip radius compensation,surface reconstruction,and uncertainty analysis.Apart from those classical research,the applications of the emerging deep learning technique in some specific tasks of measurement are introduced.Furthermore,some potential and promising trends are provided for future investigation.展开更多
An automatic surface quality inspection system installed on a finishing lineof cold rolled strips is introduced. The system is able to detect surface defects on cold rolledstrips, such as scratches, coil breaks, rusts...An automatic surface quality inspection system installed on a finishing lineof cold rolled strips is introduced. The system is able to detect surface defects on cold rolledstrips, such as scratches, coil breaks, rusts, roll imprints, and so on. Multiple CCD area scancameras were equipped to capture images of strip surface simultaneously. Defects were detectedthrough 'Dark-field illumination' which is generated by LED illuminators. Parallel computationtechnique and fast processing algorithms were developed for real-time data processing. Theapplication to the production line shows that the system is able to detect defects effectively.展开更多
A new surface inspection system for cold rolled strips based on image processing is introduced. The system is equipped withtwo different illumination structures and CCD matrix cameras. The structure and image processi...A new surface inspection system for cold rolled strips based on image processing is introduced. The system is equipped withtwo different illumination structures and CCD matrix cameras. The structure and image processing of the inspection system are described. Some efficient algorithms for image processing and classification are presented. The system is tested with strip samples fromcold rolling plants. The results show that the system can detect and recognize six common defects of cold rolled strips successfully.展开更多
The detection and classification of real-time surface defects play an important role in automotive sheet inspection and production. In this paper, an automatic surface inspection system (ASIS) based on signal proces...The detection and classification of real-time surface defects play an important role in automotive sheet inspection and production. In this paper, an automatic surface inspection system (ASIS) based on signal processing in Baosteel NO. 4 cold-rolled plant is briefly presented. We demonstrate that the strip surface defect properties such as image, type, pitch, and position can be accurately calculated and classified by the automatic surface inspection system. In the manufacturing of the high-quality cold-rolled strips, it is necessary that the real-time surface defects can be detected and transferred by the automatic surface inspection system combined with annealing lines and recoiling lines.展开更多
In manufacture of precise optical products, it is important to inspect and classify the potential defects existing on the products’ surfaces after precise machining in order to obtain high quality in both functionali...In manufacture of precise optical products, it is important to inspect and classify the potential defects existing on the products’ surfaces after precise machining in order to obtain high quality in both functionality and aesthetics. The existing methods for detecting and classifying defects all are low accuracy or efficiency or high cost in inspection process. In this paper, a new inspection system based on machine vision has been introduced, which uses automatic focusing and image mosaic technologies to rapidly acquire distinct surface image, and employs Case-Based Reasoning(CBR)method in defects classification. A modificatory fuzzy similarity algorithm in CBR has been adopted for more quick and robust need of pattern recognition in practice inspection. Experiments show that the system can inspect surface diameter of 500mm in half an hour with resolving power of 0.8μm diameter according to digs or 0.5μm transverse width according to scratches. The proposed inspection principles and methods not only have meet manufacturing requirements of precise optical products, but also have great potential applications in other fields of precise surface inspection.展开更多
Laser-induced breakdown spectroscopy(LIBS) was examined to detect a trace substance adhered onto Al alloys for the surface inspection of materials to be adhesively bonded. As an example of Si contamination, silicone o...Laser-induced breakdown spectroscopy(LIBS) was examined to detect a trace substance adhered onto Al alloys for the surface inspection of materials to be adhesively bonded. As an example of Si contamination, silicone oil was employed and sprayed onto substrates with a controlled surface concentration. LIBS measurements employing nanosecond UV pulses(λ?=?266 nm) and an off-axis emission collection system with different detecting heights were performed. Because surface contaminants are involved in the plasma formed by laser ablation of the substrates, the relative contribution of the surface contaminants and the substrates to the plasma emission could be changed depending on the conditions for plasma formation. The limit of detection(LOD) was evaluated under several detecting conditions for investigating the factors that affected the LOD. A significant factor was the standard deviation values of signal intensities obtained for the clean substrates. This value varied depending on the measurement conditions.For the Al alloy(A6061), the smallest LOD obtained was 0.529 μg?·?cm^(-2). Furthermore, an improved LOD(0.299 μg?·?cm^(-2)) was obtained for the Al alloy with a lower Si content.展开更多
In this paper, an automatic inspection system for weld surface appearance using machine vision has been developed to recognize weld surface defects such as porosities, cracks, etc. It can replace conventional manual v...In this paper, an automatic inspection system for weld surface appearance using machine vision has been developed to recognize weld surface defects such as porosities, cracks, etc. It can replace conventional manual visual inspection method, which is tedious, time-consuming, subjective, experience-depended, and sometimes biased. The system consists of a CCD camera, a self-designed annular light source, a sensor controller, a frame grabbing card, a computer and so on. After acquiring weld surface appearance images using CCD, the images are preprocessed using median filtering and a series of image enhancement algorithms. Then a dynamic threshold and morphology algorithms are applied to segment defect object. Finally, defect features information is obtained by eight neighborhoods boundary chain code algorithm. Experimental results show that the developed system is capable of inspecting most surface defects such as porosities, cracks with high reliability and accuracy.展开更多
In strip surface quality inspection systems based on the machine vision detection technology ,image quality is a key factor affecting the final detection performance. Composite imaging methods, such as bright and dark...In strip surface quality inspection systems based on the machine vision detection technology ,image quality is a key factor affecting the final detection performance. Composite imaging methods, such as bright and dark field imaging or reflection and transmission imaging, can reveal more information by emphasizing different image aspects. Defect detection rates and defect recognition accuracy can be improved by integrating and matching information from different image acquisition settings. Practical application shows that transmission and reflection composite imaging can improve the imaging quality of penetrative defects, while bright and dark field composite imaging can enhance imaging of defects such as color deviation and stains.展开更多
A methodology for CAD-directed measurement of freeform surface using a coordinate measuring machine equipped with a touch-trigger probe is presented, mainly including adaptive sampling of measurement points and regist...A methodology for CAD-directed measurement of freeform surface using a coordinate measuring machine equipped with a touch-trigger probe is presented, mainly including adaptive sampling of measurement points and registration of freeform surface. The proposed sampling method follows four steps: Freeform surface is fitted by bi-cubic B-spline; Curvedness measure of the surface is computed; Given a number of sampling points, an iterative algorithm is constructed for selecting a set of measurement points by employing the curvedness information; The measurement points is regularized for tradeoff between maximizing the measurement accuracy and minimizing the sampling time and cost. The aforesaid algorithm is demonstrated in term of a marine propeller blade. An offset surface registration method is presented to improve alignment accuracy of freeform objects, and Monte Carlo simulation is conducted to verify the effectiveness of the method.展开更多
An intelligent camera for surface defect inspection is presented which can pre-process the surface image of a rolled strip and pick defective areas out at a spead of 1 600 meters per minute. The camera is made up of a...An intelligent camera for surface defect inspection is presented which can pre-process the surface image of a rolled strip and pick defective areas out at a spead of 1 600 meters per minute. The camera is made up of a high speed line CCD, a 60 Mb/s CCD digitizer with correlated double sampling function, and a field programmable gate array(FPGA), which can quickly distinguish defective areas using a perceptron embedded in FPGA thus the data to be further processed would dramatically be reduced. Some experiments show that the camera can meet high producing speed, and reduce cost and complexity of automation surface inspection systems.展开更多
The pipe inspection robot system is developed for automatic inspection of gas pipeline with pipe diameter between 400 mm and 650 mm. It is composed of a pipe robot crawling mechanism controlled by remote network syste...The pipe inspection robot system is developed for automatic inspection of gas pipeline with pipe diameter between 400 mm and 650 mm. It is composed of a pipe robot crawling mechanism controlled by remote network system, nondestructive examination sensor system, ground working station and so on. This paper presents the pipe inspection robot system design, the Key technique and the performance experiment of the robot. The main performance index of the pipe robot system prototype has reached domestic advanced level. The prototype has also the technical potential to be developed as a product used in industry for periodic check of main gas/oil pipe.展开更多
The study on Traditional Chinese Medicine (TCM)by the technology and method of thermal science is a new cut in point in interdisciplinary science, and its purpose is to study the tongue inspection in TCM from the view...The study on Traditional Chinese Medicine (TCM)by the technology and method of thermal science is a new cut in point in interdisciplinary science, and its purpose is to study the tongue inspection in TCM from the view of the bio heat transfer theory. In this paper human tongues were studied with the infrared thermal imaging technology. And the characteristic relationship between temperature distribution and age, tongue color as well as infrared thermal tongue image concerning the characteristic of viscera was analyzed by the experimental data,which confirms that the change in temperature distribution in different positions of the tongue is related to the diseases of different internal organs of the body. From a series of invasive experiments in animals, the blood perfusion rate was measured with the equipment of CBI 8000 Doppler Blood Flow Meter and MP 100 Physiologic Research System for the first time and the characteristic relationship curve between the temperature on the surface of the tongue and the blood perfusion rate was obtained. From the experiments the temperature on the surface of the tongue reflects objectively the tongue color which is influenced by the blood perfusion rate. This will help to develop some new cognition in the theory of TCM.展开更多
To address the shortcomings of traditional filtering methods that utilize the scattering method for the online detection of strip surface roughness and to improve the accuracy of the identification of strip surface ro...To address the shortcomings of traditional filtering methods that utilize the scattering method for the online detection of strip surface roughness and to improve the accuracy of the identification of strip surface roughness,in this paper,a regression-smoothing adaptive-filtering method was investigated for use in the online detection of surface roughness in the cold-rolled strip. The results show that by the use of robust locally weighted regression to perform noise-reduction preprocessing of the initial parameters in the online detection of surface roughness,followed by the establishment of a kernel function,the regression-smoothing adaptive-filtering method can update the weight based on the relative positions of historical and current data. When the changes in neighboring data exceed the established threshold value of 0. 75 μm,the width of the smoothing window is automatically reduced,thereby realizing adaptive variable-step regression-smoothing filtering of online roughness detection data. By the use of this regression-smoothing adaptive-filtering method,the accuracy of detecting the surface roughness of a cold-rolled strip can be improved and the requirements of downstream users better satisfied.展开更多
基金partially supported by the Natural Science Foundation of Shanghai(Grant No.22ZR1435200)the National Natural Science Foundation of China(Grant No.52075337)the Open Research Fund of State Key Laboratory of Digital Manufacturing and Equipment Technology,HUST(Grant No.DMETKF2022010)。
文摘Parts with high-quality freeform surfaces have been widely used in industries,which require strict quality control during the manufacturing process.Among all the industrial inspection methods,contact measurement with coordinate measuring machines or computer numerical control machine tool is a fundamental technique due to its high accuracy,robustness,and universality.In this paper,the existing research in the contact measurement field is systematically reviewed.First,different configurations of the measuring machines are introduced in detail,which may have influence on the corresponding sampling and inspection path generation criteria.Then,the entire inspection pipeline is divided into two stages,namely the pre-inspection and post-inspection stages.The typical methods of each sub-stage are systematically overviewed and classified,including sampling,accessibility analysis,inspection path generation,probe tip radius compensation,surface reconstruction,and uncertainty analysis.Apart from those classical research,the applications of the emerging deep learning technique in some specific tasks of measurement are introduced.Furthermore,some potential and promising trends are provided for future investigation.
基金This work was financed by the National Natural Science Foundation of China (No.50074010) "863 Program" of China (No. 2001AA339030).]
文摘An automatic surface quality inspection system installed on a finishing lineof cold rolled strips is introduced. The system is able to detect surface defects on cold rolledstrips, such as scratches, coil breaks, rusts, roll imprints, and so on. Multiple CCD area scancameras were equipped to capture images of strip surface simultaneously. Defects were detectedthrough 'Dark-field illumination' which is generated by LED illuminators. Parallel computationtechnique and fast processing algorithms were developed for real-time data processing. Theapplication to the production line shows that the system is able to detect defects effectively.
文摘A new surface inspection system for cold rolled strips based on image processing is introduced. The system is equipped withtwo different illumination structures and CCD matrix cameras. The structure and image processing of the inspection system are described. Some efficient algorithms for image processing and classification are presented. The system is tested with strip samples fromcold rolling plants. The results show that the system can detect and recognize six common defects of cold rolled strips successfully.
文摘The detection and classification of real-time surface defects play an important role in automotive sheet inspection and production. In this paper, an automatic surface inspection system (ASIS) based on signal processing in Baosteel NO. 4 cold-rolled plant is briefly presented. We demonstrate that the strip surface defect properties such as image, type, pitch, and position can be accurately calculated and classified by the automatic surface inspection system. In the manufacturing of the high-quality cold-rolled strips, it is necessary that the real-time surface defects can be detected and transferred by the automatic surface inspection system combined with annealing lines and recoiling lines.
文摘In manufacture of precise optical products, it is important to inspect and classify the potential defects existing on the products’ surfaces after precise machining in order to obtain high quality in both functionality and aesthetics. The existing methods for detecting and classifying defects all are low accuracy or efficiency or high cost in inspection process. In this paper, a new inspection system based on machine vision has been introduced, which uses automatic focusing and image mosaic technologies to rapidly acquire distinct surface image, and employs Case-Based Reasoning(CBR)method in defects classification. A modificatory fuzzy similarity algorithm in CBR has been adopted for more quick and robust need of pattern recognition in practice inspection. Experiments show that the system can inspect surface diameter of 500mm in half an hour with resolving power of 0.8μm diameter according to digs or 0.5μm transverse width according to scratches. The proposed inspection principles and methods not only have meet manufacturing requirements of precise optical products, but also have great potential applications in other fields of precise surface inspection.
基金supported by a future pioneering project commissioned by the New Energy and Industrial Technology Development Organization (NEDO)
文摘Laser-induced breakdown spectroscopy(LIBS) was examined to detect a trace substance adhered onto Al alloys for the surface inspection of materials to be adhesively bonded. As an example of Si contamination, silicone oil was employed and sprayed onto substrates with a controlled surface concentration. LIBS measurements employing nanosecond UV pulses(λ?=?266 nm) and an off-axis emission collection system with different detecting heights were performed. Because surface contaminants are involved in the plasma formed by laser ablation of the substrates, the relative contribution of the surface contaminants and the substrates to the plasma emission could be changed depending on the conditions for plasma formation. The limit of detection(LOD) was evaluated under several detecting conditions for investigating the factors that affected the LOD. A significant factor was the standard deviation values of signal intensities obtained for the clean substrates. This value varied depending on the measurement conditions.For the Al alloy(A6061), the smallest LOD obtained was 0.529 μg?·?cm^(-2). Furthermore, an improved LOD(0.299 μg?·?cm^(-2)) was obtained for the Al alloy with a lower Si content.
文摘In this paper, an automatic inspection system for weld surface appearance using machine vision has been developed to recognize weld surface defects such as porosities, cracks, etc. It can replace conventional manual visual inspection method, which is tedious, time-consuming, subjective, experience-depended, and sometimes biased. The system consists of a CCD camera, a self-designed annular light source, a sensor controller, a frame grabbing card, a computer and so on. After acquiring weld surface appearance images using CCD, the images are preprocessed using median filtering and a series of image enhancement algorithms. Then a dynamic threshold and morphology algorithms are applied to segment defect object. Finally, defect features information is obtained by eight neighborhoods boundary chain code algorithm. Experimental results show that the developed system is capable of inspecting most surface defects such as porosities, cracks with high reliability and accuracy.
文摘In strip surface quality inspection systems based on the machine vision detection technology ,image quality is a key factor affecting the final detection performance. Composite imaging methods, such as bright and dark field imaging or reflection and transmission imaging, can reveal more information by emphasizing different image aspects. Defect detection rates and defect recognition accuracy can be improved by integrating and matching information from different image acquisition settings. Practical application shows that transmission and reflection composite imaging can improve the imaging quality of penetrative defects, while bright and dark field composite imaging can enhance imaging of defects such as color deviation and stains.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2002AA424012).
文摘A methodology for CAD-directed measurement of freeform surface using a coordinate measuring machine equipped with a touch-trigger probe is presented, mainly including adaptive sampling of measurement points and registration of freeform surface. The proposed sampling method follows four steps: Freeform surface is fitted by bi-cubic B-spline; Curvedness measure of the surface is computed; Given a number of sampling points, an iterative algorithm is constructed for selecting a set of measurement points by employing the curvedness information; The measurement points is regularized for tradeoff between maximizing the measurement accuracy and minimizing the sampling time and cost. The aforesaid algorithm is demonstrated in term of a marine propeller blade. An offset surface registration method is presented to improve alignment accuracy of freeform objects, and Monte Carlo simulation is conducted to verify the effectiveness of the method.
基金Supported by the National Natural Science Foundation of China (No. 60872096) and the Fundamental Research Funds for the Central Universities (No. 2009B31914).
文摘An intelligent camera for surface defect inspection is presented which can pre-process the surface image of a rolled strip and pick defective areas out at a spead of 1 600 meters per minute. The camera is made up of a high speed line CCD, a 60 Mb/s CCD digitizer with correlated double sampling function, and a field programmable gate array(FPGA), which can quickly distinguish defective areas using a perceptron embedded in FPGA thus the data to be further processed would dramatically be reduced. Some experiments show that the camera can meet high producing speed, and reduce cost and complexity of automation surface inspection systems.
基金This Research is Supported by the High Technology Research and Development (863) Programme of China(No.:2002AA442110)
文摘The pipe inspection robot system is developed for automatic inspection of gas pipeline with pipe diameter between 400 mm and 650 mm. It is composed of a pipe robot crawling mechanism controlled by remote network system, nondestructive examination sensor system, ground working station and so on. This paper presents the pipe inspection robot system design, the Key technique and the performance experiment of the robot. The main performance index of the pipe robot system prototype has reached domestic advanced level. The prototype has also the technical potential to be developed as a product used in industry for periodic check of main gas/oil pipe.
基金SupportedbyNationalNaturalScienceFoundationofChina(No.59976026ndTianjinNaturalScienceFoundation (No .0 0 36 0 771 1 )
文摘The study on Traditional Chinese Medicine (TCM)by the technology and method of thermal science is a new cut in point in interdisciplinary science, and its purpose is to study the tongue inspection in TCM from the view of the bio heat transfer theory. In this paper human tongues were studied with the infrared thermal imaging technology. And the characteristic relationship between temperature distribution and age, tongue color as well as infrared thermal tongue image concerning the characteristic of viscera was analyzed by the experimental data,which confirms that the change in temperature distribution in different positions of the tongue is related to the diseases of different internal organs of the body. From a series of invasive experiments in animals, the blood perfusion rate was measured with the equipment of CBI 8000 Doppler Blood Flow Meter and MP 100 Physiologic Research System for the first time and the characteristic relationship curve between the temperature on the surface of the tongue and the blood perfusion rate was obtained. From the experiments the temperature on the surface of the tongue reflects objectively the tongue color which is influenced by the blood perfusion rate. This will help to develop some new cognition in the theory of TCM.
文摘To address the shortcomings of traditional filtering methods that utilize the scattering method for the online detection of strip surface roughness and to improve the accuracy of the identification of strip surface roughness,in this paper,a regression-smoothing adaptive-filtering method was investigated for use in the online detection of surface roughness in the cold-rolled strip. The results show that by the use of robust locally weighted regression to perform noise-reduction preprocessing of the initial parameters in the online detection of surface roughness,followed by the establishment of a kernel function,the regression-smoothing adaptive-filtering method can update the weight based on the relative positions of historical and current data. When the changes in neighboring data exceed the established threshold value of 0. 75 μm,the width of the smoothing window is automatically reduced,thereby realizing adaptive variable-step regression-smoothing filtering of online roughness detection data. By the use of this regression-smoothing adaptive-filtering method,the accuracy of detecting the surface roughness of a cold-rolled strip can be improved and the requirements of downstream users better satisfied.