Collinear Constraint Based Mobile Vision Coordinate Measurement System

2008 ◽  
Vol 381-382 ◽  
pp. 87-90
Author(s):  
Zhi Jing Yu ◽  
X. Li ◽  
X. Si ◽  
J. Zhu ◽  
D. He ◽  
...  
Keyword(s):  
High Resolution ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Ccd Camera ◽  
Bundle Adjustment ◽  
Online Measurement ◽  
Feature Points ◽  
Coordinate Measurement ◽  
Fully Automatic ◽  
Mobile Vision

A fully automatic and rather flexible mobile vision 3D coordinate online measurement system is presented and analyzed. The system is composed of a high resolution CCD camera, retro-reflective feature points, and an external orientation device. The feature points, which fixed on the measured object and external orientation device, are imaged by camera in several locations and orientations. The initial external locations and orientations of the camera relative to the fixed external orientation device are determined by pose estimate algorithm, and the feature points coordinates, i.e. measured points coordinates on the object, are calculated by bundle adjustment algorithm based on collinear constraint. To improve the measurement accuracy, the locations of the imaging feature points are determined by bilinear centroid sub-pixel algorithm. The effectiveness of the proposed system has been tested by experiments.

Online Stereo Vision Coordinate Measurement System Using on Aircraft Assembly

2008 ◽  
Vol 381-382 ◽  
pp. 207-210
Author(s):  
Zhi Jing Yu ◽  
X.X. Li ◽  
D.R. He ◽  
Ji Gui Zhu ◽  
X.Y. Si ◽  
...  
Keyword(s):  
Stereo Vision ◽  
Measurement Accuracy ◽  
Vision System ◽  
Online Measurement ◽  
Feature Points ◽  
Epipolar Constraint ◽  
Coordinate Measurement ◽  
Aircraft Assembly ◽  
Measurement Results ◽  
Fully Automatic

An optical imaging based fully automatic stereo vision system for aircraft assembly online measurement is presented and analyzed. In this system, the relative position of the two cameras can easily calibrated by imaging an optical reference bar in different locations and orientations throughout the measurement space according to epipolar constraint and the certified distance of the features on the reference bar. For measurement, the system takes infrared LEDs which attached at measured object as imaging targets, and makes use of the measurement results of these feature points space coordinates to calculate the related positions of the assembly aircraft parts. Furthermore, using automatic infrared LED light intensity and CCD cameras exposure time improve the calibration and measurement accuracy. The effectiveness of the proposed system has been test by experiments.

Research on the influence of background light on the accuracy of a three-dimensional coordinate measurement system based on dual-PSD

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaohong Lu ◽  
Yu Zhou ◽  
Jinhui Qiao ◽  
Yihan Luan ◽  
Yongquan Wang
Keyword(s):  
Neural Network ◽  
Measurement System ◽  
Bp Neural Network ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Electrical Method ◽  
Content Type ◽  
Coordinate Measurement ◽  
Background Light ◽  
Three Dimensional Coordinate

Purpose The purpose of this paper is to analyze the measurement error of a three-dimensional coordinate measurement system based on dual-position-sensitive detector (PSD) under different background light. Design/methodology/approach The mind evolutionary algorithm (MEA)-back propagation (BP) neural network is used to predict the three-dimensional coordinates of the points, and the influence of the background light on the measurement accuracy of the three-dimensional coordinates based on PSD is obtained. Findings The influence of the background light on the measurement accuracy of the system is quantitatively calculated. The background light has a significant influence on the prediction accuracy of the three-dimensional coordinate measurement system. The optical method, electrical method and photoelectric compensation method are proposed to improve the measurement accuracy. Originality/value BP neural network based on MEA is applied to the coordinate prediction of the three-dimensional coordinate measurement system based on dual-PSD, and the influence of background light on the measurement accuracy is quantitatively analyzed.

Design and Calibration of Real-Time 3D Coordinate Measurement System Based on Multi-Angle Intersection and Cylindrical Imaging

2017 ◽  
Vol 870 ◽  
pp. 147-152
Author(s):  
Ling Hui Yang ◽  
Li Jun Wang ◽  
Hai Qing Liu ◽  
Yong Jie Ren ◽  
Jia Rui Lin ◽  
...  
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Measurement System ◽  
Calibration Method ◽  
Light Spot ◽  
Frame Rate ◽  
Coordinate Measurement ◽  
Linear Ccd ◽  
Angle Measuring ◽  
Plane Passing

This paper presents a high-resolution real-time 3D coordinate measurement system based on multi-angle intersection and cylindrical imaging. The measuring angle is detected by the linear camera equipped with cylindrical lenses, whose field of view is a 3D space rather than 2D plane. This camera has prominent advantages in precise coordinate measurement and dynamic position tracking due to the high resolution and outstanding frame rate of linear CCD. Each camera is a 1D angle measuring unit which confirms an angle thereby a plane passing through the light spot. With three cameras arrangement in front of the measurement field, the 3D coordinate of the light spot can be reconstructed by multi-angle intersection. An accurate and generic calibration method is introduced to calibrate this camera. The proposed calibration method is based on nonparametric ideas to find the mapping from incoming scene rays to photo-sensitive elements, and this method (black box calibration) is still effective even if the lens distortion is high and asymmetric. It is applicable to a central (single viewpoint) camera equipped with any lenses. The proposed calibration method is applied to the 3D coordinate measurement system. The coordinate measurement accuracy of the designed system is better than 0.49mm.

scholarly journals Progress Report for the KAO 1.0 meter Robotic Telescope

2001 ◽  
Vol 183 ◽  
pp. 103-110 ◽  
Author(s):  
Peter Mack ◽  
Wonyong Han ◽  
Matthew Bradstreet ◽  
Anthony Borstad ◽  
Jang-Hyun Park ◽  
...  
Keyword(s):  
High Resolution ◽  
Ccd Camera ◽  
Progress Report ◽  
The Internet ◽  
Astronomy Observatory ◽  
Control Software ◽  
Design Concepts ◽  
Fully Automatic ◽  
Robotic Telescope ◽  
A Company

AbstractKorea Astronomy Observatory (KAO) is working to rebuild a 1.0-m robotic telescope in collaboration with a company (Astronomical Consultants & Equipment, Inc. or ACE). The telescope is being totally refurbished to make a fully automatic telescope which can operate in both interactive an fully autonomous robotic modes. This paper describes the design concepts and the work completed. The telescope is an f/7.5 Ritchey-Chretien system mounted on an equatorial fork with friction drives capable of high slewing (5°/s2) and high resolution tracking. The control software manages the entire telescope, instruments and observatory. In interactive local and remote modes the observer can manually enter coordinates or retrieve them from a database. In robotic mode the telescope controller downloads requests from users and creates a schedule. The telescope will be equipped with a CCD camera and will be available over the internet.

On-line alignment and astigmatism correction using a TV and personal computer

1993 ◽  
Vol 51 ◽  
pp. 202-203
Author(s):  
F. Hosokawa ◽  
Y. Kondo ◽  
T. Honda ◽  
Y. Ishida ◽  
M. Kersker
Keyword(s):  
High Resolution ◽  
Personal Computer ◽  
Block Diagram ◽  
Incident Beam ◽  
Ccd Camera ◽  
Alignment Procedure ◽  
Astigmatism Correction ◽  
Transmission Electron ◽  
Alignment System ◽  
On Line

High-resolution transmission electron microscopy must attain utmost accuracy in the alignment of incident beam direction and in astigmatism correction, and that, in the shortest possible time. As a method to eliminate this troublesome work, an automatic alignment system using the Slow-Scan CCD camera has been introduced recently. In this method, diffractograms of amorphous images are calculated and analyzed to detect misalignment and astigmatism automatically. In the present study, we also examined diffractogram analysis using a personal computer and digitized TV images, and found that TV images provided enough quality for the on-line alignment procedure of high-resolution work in TEM. Fig. 1 shows a block diagram of our system. The averaged image is digitized by a TV board and is transported to a computer memory, then a diffractogram is calculated using an FFT board, and the feedback parameters which are determined by diffractogram analysis are sent to the microscope(JEM- 2010) through the RS232C interface. The on-line correction system has the following three modes.

scholarly journals High-Resolution Atmospheric Sensing of Multiple Atmospheric Variables Using the DataHawk Small Airborne Measurement System

2013 ◽  
Vol 30 (10) ◽  
pp. 2352-2366 ◽  
Author(s):  
Dale A. Lawrence ◽  
Ben B. Balsley
Keyword(s):  
High Resolution ◽  
Measurement System ◽  
Current System ◽  
Low Cost ◽  
Structure Constant ◽  
Turbulence Structure ◽  
Quality Of Data ◽  
Airborne Measurement ◽  
Atmospheric Measurement ◽  
Atmospheric Variables

Abstract The DataHawk small airborne measurement system provides in situ atmospheric measurement capabilities for documenting scales as small as 1 m and can access reasonably large volumes in and above the atmospheric boundary layer at low cost. The design of the DataHawk system is described, beginning with the atmospheric measurement requirements, and articulating five key challenges that any practical measurement system must overcome. The resulting characteristics of the airborne and ground support components of the DataHawk system are outlined, along with its deployment, operating, and recovery modes. Typical results are presented to illustrate the types and quality of data provided by the current system, as well as the need for more of these finescale measurements. Particular focus is given to the DataHawk's ability to make very-high-resolution measurements of a variety of atmospheric variables simultaneously, with emphasis given to the measurement of two important finescale turbulence parameters, (the temperature turbulence structure constant) and ɛ (the turbulent energy dissipation rate). Future sensing possibilities and limitations using this approach are also discussed.

Research on Online Measurement Method of Hole Diameter and Position

2013 ◽  
Vol 347-350 ◽  
pp. 197-200
Author(s):  
Yu Gong ◽  
Jing Cai Zhang ◽  
Hong Qi Liu
Keyword(s):  
Comparative Analysis ◽  
Measurement System ◽  
Measurement Method ◽  
Measurement Methods ◽  
Hole Diameter ◽  
Laser Sensor ◽  
Online Measurement ◽  
Online Detection ◽  
Ccd Imaging ◽  
Inductive Sensor

In this paper, research on measurement methods of hole during the parts online detection has been made. Both diameter and position of the hole are going to be detected in the same measurement system. In order to obtain higher accuracy and efficiency, a comparative analysis test of using the contact probes, the inductive sensor, the laser sensor, the forward and back lighting CCD imaging have been achieved. Results show that the contact measurement using inductive sensor is more suitable for the system, for the reason that it has higher reliability and efficiency.

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