The dense and accurate measurement of 3D texture is helpful in evaluating the pavement function.To form dense mandatory constraints and improve matching accuracy,the traditional binocular reconstruction technology was...The dense and accurate measurement of 3D texture is helpful in evaluating the pavement function.To form dense mandatory constraints and improve matching accuracy,the traditional binocular reconstruction technology was improved threefold.First,a single moving laser line was introduced to carry out global scanning constraints on the target,which would well overcome the difficulty of installing and recognizing excessive laser lines.Second,four kinds of improved algorithms,namely,disparity replacement,superposition synthesis,subregion segmentation,and subregion segmentation centroid enhancement,were established based on different constraint mechanism.Last,the improved binocular reconstruction test device was developed to realize the dual functions of 3D texture measurement and precision self-evaluation.Results show that compared with traditional algorithms,the introduction of a single laser line scanning constraint is helpful in improving the measurement’s accuracy.Among various improved algorithms,the improvement effect of the subregion segmentation centroid enhancement method is the best.It has a good effect on both overall measurement and single pointmeasurement,which can be considered to be used in pavement function evaluation.展开更多
The temperature field in laser line scanning thermography is investigated comprehensively in this work,including analytical calculation and experiment.Firstly,the principle of laser line scanning thermography is analy...The temperature field in laser line scanning thermography is investigated comprehensively in this work,including analytical calculation and experiment.Firstly,the principle of laser line scanning thermography is analyzed.On this basis,a physical laser line scanning model is proposed.Afterwards,based on Fourier transform(FT)and segregation variablemethod(SVM),the heat conduction differential equation in laser line scanning thermography is derived in detail.The temperature field of the composite-based coatings model with defects is simulated numerically.The results show that the laser line scanning thermography can effectively detect the defects in the model.The correctness of the analytical calculation is verified by comparing the surface temperature distribution obtained by analytical calculation and numerical simulation.Additionally,an experiment is carried out and the changeable surface temperature obtained by analytical calculation is compared with the experimental results.It shows that the error of maximum temperature obtained by analytical calculation and by experiment is 8%with high accuracy,which proves the correctness of analytical calculation and enriches the theoretical foundation of laser line scanning thermography.展开更多
This paper analyzes the operation parameters of the time delay and integration (TDI) line scan CCD camera, such as resolution, line rate, clock frequency, etc. and their mathematical relationship is deduced. By analyz...This paper analyzes the operation parameters of the time delay and integration (TDI) line scan CCD camera, such as resolution, line rate, clock frequency, etc. and their mathematical relationship is deduced. By analyzing and calculating these parameters, the working clocks of the TDI CCD line scan camera are designed, which guarantees the synchronization of the line scan rate and the camera movement speed. The IL-E2 TDI CCD of DALSA Co. is used as the sensor of the camera in the paper. The working clock generator used for the TDI CCD sensor is realized by using the programmable logic device (PLD). The experimental results show that the working clock generator circuit satisfies the requirement of high speed TDI CCD line scan camera.展开更多
The cross section of the Ru Porcelain sherds is analyzed from glaze to body for main elemental contents with EDXRF probe line scanning method. It is found that a midst layer with great variety of elemental contents ex...The cross section of the Ru Porcelain sherds is analyzed from glaze to body for main elemental contents with EDXRF probe line scanning method. It is found that a midst layer with great variety of elemental contents exists from glaze to body. Furthermore, every elemental content changes continuously and each has different shapes with different jumping-off points and end- points. It is certain that the midst layer is formed during the process of porcelain firing, when vitreous glaze infiltrates into the surface of porcelain body. It also well fits the phenomenon observed through different microscopes (stereo-microscope, polarizing microscope and SEM).展开更多
A system with uniform light reflection in the inner surface within a horizontal 2/3 cylindrical structure for line-scan CCD of the print testing was designed. The design was based on diffuse reflection uniformity of t...A system with uniform light reflection in the inner surface within a horizontal 2/3 cylindrical structure for line-scan CCD of the print testing was designed. The design was based on diffuse reflection uniformity of the integrating sphere and requirement of the strip uniform illumination region. This system was called dome light. White light LED array light sources were used for uniform illumi- nation. The LEDs were filtrated to composite array light source based on coefficient of variation of a single LED. The standard white board and SG color checkers were used in the line-scan CCD imaging experiments under the dome light and ordinary illumination light source. The average color difference (AE) of SG color checkers in CIELAB space was 2. 091 under the dome light and 2. 286 under ordinary illumination light source respectively. Experimental results indicate that the dome light can satisfy illumination uniformity and color rendering consistency for line-scan CCD and provide a standard light source for uniform calibration of different cameras.展开更多
As the development of machine vision technology, the color line-scan system is widely applied in the on-line inspection. Due to the non-uniform gray scale and color distortion of the image acquired by the system, the ...As the development of machine vision technology, the color line-scan system is widely applied in the on-line inspection. Due to the non-uniform gray scale and color distortion of the image acquired by the system, the image correction is needed to reduce the problem of image processing and the stability system. Based on reasons mentioned above, a method that using polynomial fitting to correct the image is presented to solve the problem in this paper. The method has been used in the automatic optical inspection of PCB, and has been proved to be effective. So this method will have a potential application to the development of the color line-scan machine vision system.展开更多
基金supported by National Natural Science Foundation of China (52178422)Doctoral Research Foundation of Hubei University of Arts and Science (2059047)National College Students’Innovation and Entrepreneurship Training Program (202210519021).
文摘The dense and accurate measurement of 3D texture is helpful in evaluating the pavement function.To form dense mandatory constraints and improve matching accuracy,the traditional binocular reconstruction technology was improved threefold.First,a single moving laser line was introduced to carry out global scanning constraints on the target,which would well overcome the difficulty of installing and recognizing excessive laser lines.Second,four kinds of improved algorithms,namely,disparity replacement,superposition synthesis,subregion segmentation,and subregion segmentation centroid enhancement,were established based on different constraint mechanism.Last,the improved binocular reconstruction test device was developed to realize the dual functions of 3D texture measurement and precision self-evaluation.Results show that compared with traditional algorithms,the introduction of a single laser line scanning constraint is helpful in improving the measurement’s accuracy.Among various improved algorithms,the improvement effect of the subregion segmentation centroid enhancement method is the best.It has a good effect on both overall measurement and single pointmeasurement,which can be considered to be used in pavement function evaluation.
基金supported by the National Natural Science Foundation of China(Grant No.52005495).
文摘The temperature field in laser line scanning thermography is investigated comprehensively in this work,including analytical calculation and experiment.Firstly,the principle of laser line scanning thermography is analyzed.On this basis,a physical laser line scanning model is proposed.Afterwards,based on Fourier transform(FT)and segregation variablemethod(SVM),the heat conduction differential equation in laser line scanning thermography is derived in detail.The temperature field of the composite-based coatings model with defects is simulated numerically.The results show that the laser line scanning thermography can effectively detect the defects in the model.The correctness of the analytical calculation is verified by comparing the surface temperature distribution obtained by analytical calculation and numerical simulation.Additionally,an experiment is carried out and the changeable surface temperature obtained by analytical calculation is compared with the experimental results.It shows that the error of maximum temperature obtained by analytical calculation and by experiment is 8%with high accuracy,which proves the correctness of analytical calculation and enriches the theoretical foundation of laser line scanning thermography.
基金Sponsored by the Research Fund of Harbin Institute of Technology (Grant No.HITMD 2001.18).
文摘This paper analyzes the operation parameters of the time delay and integration (TDI) line scan CCD camera, such as resolution, line rate, clock frequency, etc. and their mathematical relationship is deduced. By analyzing and calculating these parameters, the working clocks of the TDI CCD line scan camera are designed, which guarantees the synchronization of the line scan rate and the camera movement speed. The IL-E2 TDI CCD of DALSA Co. is used as the sensor of the camera in the paper. The working clock generator used for the TDI CCD sensor is realized by using the programmable logic device (PLD). The experimental results show that the working clock generator circuit satisfies the requirement of high speed TDI CCD line scan camera.
基金This work was supported by the National Natural Science Foundation of China(Grant No.50272064)Chinese Academy of Sciences(Grant No.KJCX-No4) Research Foundation of City University of Hong Kong(Grant No.9010007).
文摘The cross section of the Ru Porcelain sherds is analyzed from glaze to body for main elemental contents with EDXRF probe line scanning method. It is found that a midst layer with great variety of elemental contents exists from glaze to body. Furthermore, every elemental content changes continuously and each has different shapes with different jumping-off points and end- points. It is certain that the midst layer is formed during the process of porcelain firing, when vitreous glaze infiltrates into the surface of porcelain body. It also well fits the phenomenon observed through different microscopes (stereo-microscope, polarizing microscope and SEM).
基金Supported by the National Natural Science Foundation of China(61078048)
文摘A system with uniform light reflection in the inner surface within a horizontal 2/3 cylindrical structure for line-scan CCD of the print testing was designed. The design was based on diffuse reflection uniformity of the integrating sphere and requirement of the strip uniform illumination region. This system was called dome light. White light LED array light sources were used for uniform illumi- nation. The LEDs were filtrated to composite array light source based on coefficient of variation of a single LED. The standard white board and SG color checkers were used in the line-scan CCD imaging experiments under the dome light and ordinary illumination light source. The average color difference (AE) of SG color checkers in CIELAB space was 2. 091 under the dome light and 2. 286 under ordinary illumination light source respectively. Experimental results indicate that the dome light can satisfy illumination uniformity and color rendering consistency for line-scan CCD and provide a standard light source for uniform calibration of different cameras.
文摘As the development of machine vision technology, the color line-scan system is widely applied in the on-line inspection. Due to the non-uniform gray scale and color distortion of the image acquired by the system, the image correction is needed to reduce the problem of image processing and the stability system. Based on reasons mentioned above, a method that using polynomial fitting to correct the image is presented to solve the problem in this paper. The method has been used in the automatic optical inspection of PCB, and has been proved to be effective. So this method will have a potential application to the development of the color line-scan machine vision system.