A flexible calibration method based on a front-coated flat mirror is proposed for a laser light-sectioning three-dimensional(3D)measurement system. Since the calibration target and its mirror image are spatially separ...A flexible calibration method based on a front-coated flat mirror is proposed for a laser light-sectioning three-dimensional(3D)measurement system. Since the calibration target and its mirror image are spatially separated and can be recorded in an image by a camera,the proposed method requires only a single composite image that contains a non-planar checkerboard pattern,a laser strip projected on the target and their mirror images to complete the calibration of the camera and the laser plane in one step. Levenberg-Marquardt(LM)algorithm is used to optimize the system parameters,and the measurement accuracy and speed are improved to enable online 3D inspection. Static and dynamic online 3D measurements are carried out on a cup and a triple stepped shaft,respectively,to validate the proposed method. The shaft has two steps with the depth of(0.5±0.01)mm and(2±0.01)mm to be measured online when the shaft is rotated and translated at the same time. The measurement results can be output at a frequency of 7 to 11 readings per second with standard deviations of 0.040 mm and 0.051 mm. The experimental results verify the effectiveness and flexibility of the proposed method.展开更多
A new displacement measurement system is described in this paper according to the basic principles of traditional lasertriangulation method. The range of the traditional measuring method is enlarged by measuring in se...A new displacement measurement system is described in this paper according to the basic principles of traditional lasertriangulation method. The range of the traditional measuring method is enlarged by measuring in sections. Three independent CCDs, which are distributed uniformly along the optical axis, are used to achieve subsection measurement. The planemirror is regarded as a virtual detector. When imaging beam is reflected by the plane mirror, the beam is imaged on theCC D. The designed system is equivalent to add a CCD. The feasibility of the displacement measurement system is verifiedby the experiment.展开更多
Adjusting the spacers between the electron-acceptor and the elector-donor is important to design organic ternary memory material but rarely reported. In this paper, two small molecules, ZIPGA and ZIPCAD with benzene r...Adjusting the spacers between the electron-acceptor and the elector-donor is important to design organic ternary memory material but rarely reported. In this paper, two small molecules, ZIPGA and ZIPCAD with benzene ring or triphenylamine as the spacers, were designed and synthesized to fabricate memory devices. The A1/ZIPGA/indium-tin oxide （ITO） device showed ternary characteristics, whereas A1/ZIPCAD/ITO had no obvious memory characteristics. Density functional theory calculation, X-ray diffraction （XRD） and atomic force microscopy （AFM） were employed to interpret the different memory properties. ZIPGA thin film has the closer intermolecular packing and flatter surface morphology than ZIPCAD film, which was favorable to the electron migration. This work demonstrates the importance of spacers and reveals that triphenylamine may be not a good spacer in design of new memory material.展开更多
基金supported in part by the National Natural Science Foundation of China (No. 11802132)the Natural Science Foundation of Jiangsu Province(No.BK20180446)。
文摘A flexible calibration method based on a front-coated flat mirror is proposed for a laser light-sectioning three-dimensional(3D)measurement system. Since the calibration target and its mirror image are spatially separated and can be recorded in an image by a camera,the proposed method requires only a single composite image that contains a non-planar checkerboard pattern,a laser strip projected on the target and their mirror images to complete the calibration of the camera and the laser plane in one step. Levenberg-Marquardt(LM)algorithm is used to optimize the system parameters,and the measurement accuracy and speed are improved to enable online 3D inspection. Static and dynamic online 3D measurements are carried out on a cup and a triple stepped shaft,respectively,to validate the proposed method. The shaft has two steps with the depth of(0.5±0.01)mm and(2±0.01)mm to be measured online when the shaft is rotated and translated at the same time. The measurement results can be output at a frequency of 7 to 11 readings per second with standard deviations of 0.040 mm and 0.051 mm. The experimental results verify the effectiveness and flexibility of the proposed method.
基金supported by the Science and Technology Plan of Hebei Province, China (No. 10212149)
文摘A new displacement measurement system is described in this paper according to the basic principles of traditional lasertriangulation method. The range of the traditional measuring method is enlarged by measuring in sections. Three independent CCDs, which are distributed uniformly along the optical axis, are used to achieve subsection measurement. The planemirror is regarded as a virtual detector. When imaging beam is reflected by the plane mirror, the beam is imaged on theCC D. The designed system is equivalent to add a CCD. The feasibility of the displacement measurement system is verifiedby the experiment.
基金supported by the National Natural Science Foundation of China (21176164, 21336005)the Chinese-Singapore Joint Project (2012DFG41900)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘Adjusting the spacers between the electron-acceptor and the elector-donor is important to design organic ternary memory material but rarely reported. In this paper, two small molecules, ZIPGA and ZIPCAD with benzene ring or triphenylamine as the spacers, were designed and synthesized to fabricate memory devices. The A1/ZIPGA/indium-tin oxide （ITO） device showed ternary characteristics, whereas A1/ZIPCAD/ITO had no obvious memory characteristics. Density functional theory calculation, X-ray diffraction （XRD） and atomic force microscopy （AFM） were employed to interpret the different memory properties. ZIPGA thin film has the closer intermolecular packing and flatter surface morphology than ZIPCAD film, which was favorable to the electron migration. This work demonstrates the importance of spacers and reveals that triphenylamine may be not a good spacer in design of new memory material.
