检索结果-南通市图书馆

A planar capacitive sensor for 2D long-range displacement measurement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第4期14卷 252-257页

作者： Jian-ping YU Wen WANG Ke-qing LU De-qing MEI Zi-chen CHEN Department of Mechanical Engineering Zhejiang University School of Mechanical Engineering Hangzhou Dianzi University

A planar capacitive sensor(PCS) capable of 2D large-scale measurement is presented in this *** interpretation depends on independently measuring the periodic variation in capacitance caused by the change in the overlapping area of sensing electrodes on a moving plate and a fixed *** accumulating the number of quarters in each direction and the specific position in the final quarter,the large-scale measurement is *** in Xand Y-direction can be measured independently and *** shows that a shorter gap distance and a longer electrode guarantee better *** based on a PCS test bench demonstrate that the PCS has a sensitivity of 0.198 mV/μm and a resolution of 0.308 μ*** electric fringe effect and other possible measurement errors on displacement interpretation accuracy are *** study confirms the high potential of PCSs as innovative 2D long-range displacement sensors.

关键词： Planar capacitive sensor (PCS) displacement measurement 2D large-scale measurement

IN-PLANE displacement measurement OF COMPOSITE MATERIAL BY OBJECTIVE SPECKLE

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 1987年第3期3卷 291-297页

作者： Mao Tienxiang Han Jinhu Li Chunxiu Zou Rongda (Institute of Mechanics,Academia Sinica) Institute of Mechanics Academia Sinica Taiwan

The objective speckle was used to measure the in-plane displacement around the hole in acoupon specimen of composite material under tensile *** transplantation method was adopted toensure the high reflectivity of specimen surface and to obtain high quality double exposure *** adjustable spatial frequency of the whole-field pattern of the displacement made it possible to measure abroad range of strain,from elastic to *** results obtained by objective speckle agree well with thoseby Moire method.

关键词： objective speckle composite material displacement measurement Moire method

Phase-Based Optical Flow Method with Optimized Parameter Settings for Enhancing displacement measurement Adaptability

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第5期14卷 1165-1184页

作者： Zhaoxin Peng Menglian Liu Zhiliang Wang Wei Liu Xian Wang School of Mechanical Engineering Hunan University of Science and Technology Xiangtan China

To enhance the applicability and measurement accuracy of phase-based optical flow method using complex steerable pyramids in structural displacement measurement engineering applications, an improved method of optimizing parameter settings is proposed. The optimized parameters include the best measurement points of the Region of Interest (ROI) and the levels of pyramid filters. Additionally, to address the issue of updating reference frames in practical applications due to the difficulty in estimating the maximum effective measurement value, a mechanism for dynamically updating reference frames is introduced. Experimental results demonstrate that compared to representative image gradient-based displacement measurement methods, the proposed method exhibits higher measurement accuracy in engineering applications. This provides reliable data support for structural damage identification research based on vibration signals and is expected to broaden the engineering application prospects for structural health monitoring.

关键词： displacement measurement Phase-Based Optical Flow Optimized Parameter Setting

A digital moiré fringe method for displacement sensors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2016年第9期17卷 946-953页

作者： Jian WU Ting-ting ZHOU Bo YUAN Li-qiang WANG State Key Laboratory of Modern Optical Instrumentation CNERC for Optical Instrument Zhejiang University

In this study, a displacement measurement method based on digital moiré fringe is described and experimentally demonstrated. The method is formed by only one grating with a constant pitch. First, the magnified grating image is received by an imaging array and is sent to a computer. Then, the digital moiré fringes are generated by overlaying the grating image with its mirrored one. Finally, a specifically designed algorithm is used to obtain the fringes' phase difference before and after movement and calculate the displacement. This method has the effects of amplifying displacement and averaging the grating lines error, the same as the traditional moiré technique using two pieces of gratings. At the same time, the proposed system is much easier to assemble and the measurement resolution can be set more flexibly. One displacement measuring system based on this method was built up. Experiment results show that its measurement errors are less than 0.3 μm and less than 0.12 μm at the resolutions of 0.1 μm and 0.03 μm, respectively.

关键词： Digital moiré fringe displacement measurement Grating

Research on the measurement of displacement based on Grating Reticle Image

在线全文

学校读者我要写书评

暂无评论

Research on the Measurement of Displacement based on Grating...

Improved calibration method for displacement transformation coefficient in optical and visual measurements

2012 National Conference on Information Technology and Computer Science

作者： LI Hai-hua Department of Mechanical and Electrical Engineering HuaZhong University of Science and Technology WenHua College Wuhan,China FAN Juan Department of Mechanical and Electrical Engineering HuaZhong University of Science and Technology WenHua College Wuhan,China

A new method is present to get movement displacement directly when applying grating reticle to AC servo driving control system to carry on high precise orientation for the *** the optical path until grating reticle image can be gathered clearly by *** analyzing and processing the grating reticle image collected by vidicon,the mapping coefficient can be accurately calculated between grid width and *** the fore-and-aft two grating reticle images after the worktable *** phase difference of two images can be figured out by phase difference ratio arithmetic based on Lissajous *** the actual displacement of the worktable can be calculated by the mapping *** experiments show that this method can implement sub-pixel measurement easily and rapidly in micro electronics manufacture.

关键词： displacement measurement grating image processing Lissajous figure AC servo motor

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Nanotechnology and Precision Engineering 2023年第1期6卷 12-25页

作者： Haopeng Li Zurong Qiu State Key Laboratory of Precision Measuring Technology and Instruments School of Precision Instruments and Opto-electronics EngineeringTianjin UniversityTianjin 300072China

Optical and visual measurement technology is used widely in fields that involve geometric measurements,and among such technology are laser and vision-based displacement measuring modules(LVDMMs).The displacement transformation coefficient(DTC)of an LVDMM changes with the coordinates in the camera image coordinate system during the displacement measuring process,and these changes affect the displacement measurement accuracy of LVDMMs in the full field of view(FFOV).To give LVDMMs higher accuracy in the FFOV and make them adaptable to widely varying measurement demands,a new calibration method is proposed to improve the displacement measurement accuracy of LVDMMs in the ***,an image coordinate system,a pixel measurement coordinate system,and a displacement measurement coordinate system are established on the laser receiving screen of the *** addition,marker spots in the FFOV are selected,and the DTCs at the marker spots are obtained from calibration ***,a fitting method based on locally weighted scatterplot smoothing(LOWESS)is selected,and with this fitting method the distribution functions of the DTCs in the FFOV are obtained based on the DTCs at the marker ***,the calibrated distribution functions of the DTCs are applied to the LVDMM,and experiments conducted to verify the displacement measurement accuracies are *** results show that the FFOV measurement accuracies for horizontal and vertical displacements are better than±15μm and±19μm,respectively,and that for oblique displacement is better than±24μ*** with the traditional calibration method,the displacement measurement error in the FFOV is now 90%*** research on an improved calibration method has certain significance for improving the measurement accuracy of LVDMMs in the FFOV,and it provides a new method and idea for other vision-based fields in which camera parameters must be calibrated.

关键词： displacement transformation coefficient(DTC) Laser and vision-based displacement measuring module(LVDMM) displacement measurement Locally weighted scatterplot smoothing(LOWESS) Calibration method

A videogrammetric technique for measuring the vibration displacement of stay cables

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2012年第2期15卷 135-141页

作者： ZHOU Xiaoqing XIA Yong WEI Zelong WU Qingxiong College of Civil Engineering Shenzhen University3688 Nanhai RoadShenzhen 518060China Department of Civil and Structural Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina College of Civil Engineering Fuzhou University2 Xue Yuan RoadUniversity TownFuzhou 350108China

Stay cables in cable-stayed bridges are prone to large amplitude oscillations under external *** vibration of the cables is predominantly measured by using accelerometers to measure the *** dynamic displacement is then usually obtained indirectly from the double integration of the acceleration *** paper reports an experimental method of measuring the displacement of stayed cables using a digital video *** the newly developed videogrammetric technique,the video clips are transferred into image frames,from which the shape and location of the target are *** displacement time history is then *** technique is applied to a cable-stayed bridge to measure the dynamic displacement of stay *** displacement is compared with the acceleration data in the frequency and time *** results show that the displacement measured by the digital video camera is comparable to the counterparts integrated from the acceleration *** vibration frequencies identified from the acceleration are finally used to estimate the tension forces of the *** results show that the tension forces have insignificant changes after one year’s operation.

关键词： stay cable vibration displacement measurement videogrammetric technique tension force

Anisotropic optical feedback of single frequency intra-cavity He-Ne laser

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2009年第3期18卷 1141-1146页

作者：周鲁飞张斌张书练谈宜东刘维新 The State Key Laboratory of Precision measurement Technology and Instruments Department of Precision InstrumentsTsinghua University Department of Optics Science and Technology National University of Defense Technology

This paper presents the anisotropic optical feedback of a single frequency intra-cavity He-Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.

关键词： optical feedback single frequency mode competition displacement measurement

3D Microdisplacement Monitoring of Large Aircraft Assembly with Automated In Situ Calibration

在线全文

学校读者我要写书评

暂无评论

Engineering 2022年第12期19卷 105-116页

作者： Zhenyuan Jia Bing Liang Wei Liu Kun Liu Jianwei Ma School of Mechanical Engineering Dalian University of TechnologyDalian 116024China

Three-dimensional(3D)microdisplacement monitoring plays a crucial role in the assembly of large *** paper presents a broadly applicable high-precision online 3D microdisplacement monitoring method and system based on proximity sensors as well as a corresponding in situ calibration method,which can be applied under various extreme working conditions encountered in the aircraft assembly process,such as compact and obstructed spaces.A 3D monitoring model is first established to achieve 3D microdisplacement monitoring based only on the one-dimensional distances measured by proximity sensors,which concerns the extrinsic sensor parameters,such as the probe base point(PBP)and the unit displacement vector(UDV).Then,a calibration method is employed to obtain these extrinsic parameters with high precision by combining spatial transformation principles and weighted ***,calibration and monitoring experiments performed for a tailplane assembly process are *** calibration precision for the PBP is better than±10 lm in the X and Y directions and±2 lm in the Z direction,and the calibration precision for the UDV is better than 0.07°.Moreover,the accuracy of the 3D microdisplacement monitoring system can reach±15 *** general,this paper provides new insights into the modeling and calibration of 3D microdisplacement monitoring based on proximity sensors and a precise,efficient,and low-cost technical means for performing related measurements in compact spaces during the aircraft assembly process.

关键词： Aircraft manufacture Assembly Calibration Condition monitoring displacement measurement