Servo Design for a 3-D Laser-Tracking Measurement System

1996 ◽  
Vol 118 (3) ◽  
pp. 476-481 ◽  
Author(s):  
Jia-Yush Yen ◽  
Chao-Si Jeng ◽  
Kuang-Chau Fan
Keyword(s):  
Measurement System ◽  
High Speed ◽  
Optimization Technique ◽  
Three Dimensional ◽  
Laser Beams ◽  
Measurement Point ◽  
Position Measurement ◽  
Laser Tracking ◽  
Accuracy Measurement ◽  
Highly Nonlinear

This paper addresses the servo design for a real-time, laser-tracking, three-dimensional (3-D), position measurement system. The 3-D measurement system uses two sets of tracking mirrors to shine laser beams toward the measurement point. By examining the angles of these mirrors, one can calculate the position of this point. The servo loop in the measurement system corrects the mirror orientations by continuously checking and compensating the offset between the out going laser beam and the beam reflected from a retro-reflector attached to the measurement point. To achieve high speed and high accuracy measurement, the tracking servo system has to compensate for the highly nonlinear nature of the system and maintain the laser beams close to the measurement point. This paper derives the relationship between the tracking angle rotations and the measured beam offsets. By including this relationship in the system model, the linear H∞ optimization technique can be applied for controller synthesis. All the design specifications are then directly implemented.

Automated High-Dynamic-Range Three-Dimensional Optical Metrology Technique

2014 ◽  
Author(s):  
Laura Ekstrand ◽  
Song Zhang
Keyword(s):  
Exposure Time ◽  
Measurement System ◽  
High Speed ◽  
Manufacturing Industry ◽  
Dynamic Range ◽  
Three Dimensional ◽  
Optical Metrology ◽  
High Contrast ◽  
Accuracy Measurement ◽  
3D Surfaces

Measuring three-dimensional (3D) surfaces with extremely high contrast (e.g., partially shiny surfaces) is extremely difficult with optical metrology methods. Conventional techniques, which involve measurement from multiple angles or camera aperture adjustments, pose issues for high accuracy measurement in the manufacturing industry because they are difficult to automate and often induce undesirable vibrations in the calibrated measurement system. This paper presents a framework for optically capturing high-contrast 3D surfaces via flexible exposure time variation. This technique leverages the binary defocusing technique that was recently developed at Iowa State University to allow digital fringe projection with a camera exposure time far shorter than the projector’s projection period. Since the camera exposure time can be rapidly adjusted in software, the proposed technique could be automated without mechanical adjustments to the measurement system. Moreover, the exposure times are sufficiently short as to be efficiently packed into a projection period, giving this technique the potential for high speed applications. Experimental results will be presented to demonstrate the success of the proposed method.

An Acoustic System for Pipeline Profile Measurement

1983 ◽  
Vol 105 (4) ◽  
pp. 475-479
Author(s):  
H. Van Calcar
Keyword(s):  
Measurement Technique ◽  
Measurement System ◽  
Performance Enhancement ◽  
Three Dimensional ◽  
Profile Measurement ◽  
Baseline Measurement ◽  
Acoustic System ◽  
Position Measurement ◽  
Long Baseline ◽  
Hardware Configuration

This paper presents an acoustic position measurement system used for precise three-dimensional flowline profile measurement. The system measures several points along the flowline using the long-baseline measurement technique and augments this measurement with depth telemetry repeaters to maintain elevation accuracy throughout the changing installation geometry. The paper discusses both the measurement system and the performance enhancement features. The paper concludes with a discussion of the hardware configuration and the accuracy that can be expected when the technique is extended into deeper operating areas.

Quantification of Facial Motion for Objective Evaluation Using a High-Speed Three-Dimensional Face Measurement System-A Pilot Study

2006 ◽  
Vol 27 (7) ◽  
pp. 1023-1029 ◽  
Author(s):  
Seiichi Nakata ◽  
Yukio Sato ◽  
Pujitha Gunaratne ◽  
Yoshiro Suzuki ◽  
Saiko Sugiura ◽  
...  
Keyword(s):  
Pilot Study ◽  
Measurement System ◽  
High Speed ◽  
Three Dimensional ◽  
Objective Evaluation ◽  
Facial Motion ◽  
System A ◽  
Dimensional Face

A Precise Position Measurement System of Roll-to-Roll Printing Using Burst Alignment Patterns

2018 ◽  
Author(s):  
Taehyeong Kim ◽  
Dongho Oh ◽  
Youngjin Kim ◽  
Jihyeon Kim ◽  
Byeongcheol Lee
Keyword(s):  
Measurement System ◽  
High Speed ◽  
Printed Electronics ◽  
High Volume ◽  
Measurement Range ◽  
Generation Process ◽  
Position Measurement ◽  
Process Technology ◽  
Precise Position ◽  
Roll To Roll

Printed electronics is a next-generation process technology that is suitable for high speed and high volume production and can make electronic devices and circuits on flexible materials. To commercialize printed electronics, it is necessary to improve the alignment precision of printing. In order to improve the alignment precision of the roll-to-roll process, accurate measurement of the web position is required. Therefore, in the previous research of this paper, we proposed a measurement system of the moving direction and the lateral movement using an encoder. However, in the previous study, the direction of error control had to be set according to the measurement position of the encoder, and the measurement range was so narrow. In this paper, we propose a measurement system that can detect the direction of error and increase the effective measurement range using the burst alignment pattern that generates the burst signal. Applying it to roll-to-roll printing position measurement systems, measurements can be performed with greatly improved efficiency and measurement range.

Applications of High-Precise Three-Dimensional Measurement System

2011 ◽  
Vol 222 ◽  
pp. 62-65 ◽  
Author(s):  
Takeshi Hashimoto ◽  
Mitsuo Kaneko ◽  
András Rövid ◽  
Hiroaki Ohta ◽  
Akira Fukuda ◽  
...  
Keyword(s):  
Global Warming ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Long Distance ◽  
Accuracy Measurement ◽  
Close Relationship ◽  
Three Dimensional Measurement ◽  
High Accuracy Measurement ◽  
Moving Speed

To reveal the influence of global warming on glaciers, highly accurate observations of glacier movement must continue every year. It is thought that there is a close relationship between glacier moving speed and global warming. Thus, there have been precise, detailed observations of the movement of the Perito Moreno glacier in Patagonia of the Argentine Republic over the past five years. The measurement method of using GPS and an optical measuring instrument is generally used to monitor glacier movement, but the measurement accuracy attained is not optimal because of the huge size of the glacier. The measurement system used for the Perito Moreno observations, however, could realize high accuracy measurement over long distance. The measurement system is based on the principle of stereo measurement using cameras. This paper describes the results of the Perito Moreno glacier observations of this year and considers the effectiveness of glacier observation using cameras.

A Dynamic Position Measurement Method for Destructive Process of Structures Using Image Processing

2004 ◽  
Author(s):  
Hiroshi Nishizawa ◽  
Satoshi Fujita ◽  
Osamu Furuya
Keyword(s):  
Image Processing ◽  
High Precision ◽  
High Speed ◽  
Spherical Surface ◽  
Three Dimensional ◽  
Measuring System ◽  
Position Measurement ◽  
Surface Emission ◽  
Optical Motion ◽  
Optical Motion Capture

In order to clarify the destruction mechanism of large structures in large seismic movements, a non-contacting displacement measurement system with a three-dimensional dynamic position with high precision is required. We have developed a three-dimensional measuring system with image processing using optical motion capture technology. This system consists of light emitting markers installed on the object structure and plural high speed cameras which obtain images of markers’ movement simultaneously, to measure the dynamic position of the three dimensional spatial coordinates of the markers. In order to measure the dynamic position with high precision, we have ever developed sub-pixel processing method which is able to measure very small displacements of the markers by analyzing the luminance distribution. Moreover, we have developed a new marker of spherical surface emission type which formed the luminance profile to improve furthermore the accuracy in rotational movement. Shaking tests were carried out with this measuring system and the results indicated that this system using new markers had sufficient accuracy within errors of a few millimeters in the structure of a 4 meter cube. Consequently, we have acquired the potential to apply to the measurement to the 3-D Full Scale Earthquake Testing Facility (E-Defense).

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