A Displacement Measurement Method by Laser-Beam Scanning for Mapping the Interior Geometry of Pipes

1994 ◽  
Vol 116 (2) ◽  
pp. 188-192
Author(s):  
M. Mizunuma ◽  
S. Ogawa ◽  
C. Nishimura ◽  
H. Kuwano
Keyword(s):  
Laser Beam ◽  
Radial Displacement ◽  
Measurement Method ◽  
Optical Measurement ◽  
Experimental System ◽  
High Accuracy ◽  
Noncontact Mapping ◽  
Mapping System ◽  
Laser Beam Scanning ◽  
Automated Data Acquisition

This paper proposes a displacement measuring technique for detailed noncontact mapping of the interior geometry of pipes. The technique, which is based on optical measurement using triangulation, employs a laser-beam scanner to measure radial displacement. To achieve high precision, three different algorithms for calculating the displacement from sensor output are compared in experiments. One of them, which calculates the displacement by using several direction-dependent characteristic curves, gives high accuracy. The accuracy of our experimental system is ±0.2 mm for radii between 33 and 42 mm. A mapping system using this technique with automated data-acquisition and 3D rendering of the interior is also described. Its effectiveness is illustrated by the experimental results.

Precision Force Measurement Using the Levitation Mass Method (LMM)

2011 ◽  
Vol 103 ◽  
pp. 1-8
Author(s):  
Yusaku Fujii ◽  
Akihiro Takita ◽  
Jakrapong Kaewkhao ◽  
Mitra Djamal ◽  
Takao Yamaguchi
Keyword(s):  
Laser Beam ◽  
Doppler Shift ◽  
Measurement Method ◽  
Force Measurement ◽  
Inertial Force ◽  
High Accuracy ◽  
Optical Interferometer ◽  
Future Prospects ◽  
Mechanical Measurement ◽  
Shift Frequency

This paper reviews the present status and future prospects of the levitation mass method (LMM), which is a precision mechanical measurement method. The LMM has been proposed and improved by the author for 10 years. The force generated by the actuator is measured as the inertial force of the mass levitated with sufficiently small friction using an aerostatic linear bearing and connected to the moving part of the actuator. During the measurement, the Doppler shift frequency of the laser beam reflected by the mass is measured with a high accuracy with the help of an optical interferometer. Subsequently, the velocity, position, acceleration, and inertial force of the mass are calculated using based on this frequency. Simultaneously, the current and voltage supplied to the actuator are measured.

Effects of Key Parameters on the Performance of a New In-Process Optical Measurement Method

2005 ◽  
Vol 295-296 ◽  
pp. 405-410 ◽  
Author(s):  
Z. Tao ◽  
Y. Gao
Keyword(s):  
Measurement Error ◽  
Theoretical Analysis ◽  
Laser Beam ◽  
Measurement Method ◽  
Optical Measurement ◽  
New Method ◽  
Acceptable Range ◽  
Measuring Surface ◽  
Surface Profiles ◽  
Optical Measurement Method

A new in-process optical measurement method has been developed for measuring surface profiles of workpieces under the coolant condition. In this method, a laser beam passes through two additional layers. This paper presents an error analysis for the new method. The effects of key parameters on performance of the new method are examined. The theoretical analysis and experimental results show that the measurement error in this new method can be controlled within an acceptable range.

scholarly journals Video Image Correlation-Based Method Used for the Study of the Torsional Vibrations of an Adder Gearbox

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6129
Author(s):  
Ioan Száva ◽  
Botond Pál-Gálfi ◽  
Carol Ambrus ◽  
Sorin Vlase
Keyword(s):  
Vibration Analysis ◽  
Measurement Method ◽  
Optical Measurement ◽  
High Accuracy ◽  
Image Correlation ◽  
Resonance Phenomenon ◽  
Angular Vibration ◽  
Heavy Truck ◽  
Complex Construction ◽  
Angular Amplitude

In this paper, a study of the vibrations that appear in the transmission shafts of an adder gearbox used for a heavy truck is made. The truck has two engines on only one chassis and the power offered by these engines is summated and transmitted to the truck or the working machine. This type of transmission is used for oil production installation for the army. During the transportation of the installation to the workplace, only one engine is running, after mounting installation, both engines are running. This paper studies the vibrations of the adder gearbox, a complex construction, subjected to multiple operating requirements. In this regard, the authors first performed accuracy (accuracy) tests of the VIC 3D system on an original experimental mini-stand. Measurements performed on a mini disc demonstrated the validity and accuracy of the method, even if the cameras used were not high resolution. The authors applied the same principle in the case of the adder box from the truck, obtaining useful results for those in the field. The experimental method uses the facilities of a contactless optical measurement method (VIC-3D), which provides a high-accuracy quantitative linear and angular vibration analysis. The VIC measurement method offers, based on a frontal viewing of the disk during the resonance phenomenon and by simple calculus on the monitored linear displacements, the corresponding angular amplitude.

Automatic Defects Measurement on Silicon Wafer Surface by Laser Scattered Defect Pattern

2000 ◽  
Author(s):  
Satoru Takahashi ◽  
Takashi Miyoshi ◽  
Yasuhiro Takaya
Keyword(s):  
Silicon Wafer ◽  
Measurement Method ◽  
Optical Measurement ◽  
Experimental System ◽  
Wafer Surface ◽  
Objective Lens ◽  
Two Stage ◽  
Process Measurement ◽  
Defect Pattern ◽  
Wafer Surfaces

Abstract A new optical measurement method for evaluating the defects on silicon wafer surfaces quantitatively, applicable to in-process measurement, is presented. The experimental system for measuring the defects consists of a Fourier transform optical system using a high-power objective lens. In order to verify the feasibility of the applications of this method to automatic in-process measurement, a two-stage measurement for detecting and evaluating small particles, which are typical defects on silicon wafer surfaces, was carried out. The results showed that the proposed two-stage measurement method is effective for measuring small defects in the sub-micro meter scale size.

scholarly journals High-Q MEMS Resonators for Laser Beam Scanning Displays

Micromachines ◽  
2012 ◽  
Vol 3 (2) ◽  
pp. 509-528 ◽  
Author(s):  
Ulrich Hofmann ◽  
Joachim Janes ◽  
Hans-Joachim Quenzer
Keyword(s):  
Laser Beam ◽  
Beam Scanning ◽  
High Q ◽  
Mems Resonators ◽  
Laser Beam Scanning

scholarly journals Deep Learning Based Pavement Inspection Using Self-Reconfigurable Robot

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2595
Author(s):  
Balakrishnan Ramalingam ◽  
Abdullah Aamir Hayat ◽  
Mohan Rajesh Elara ◽  
Braulio Félix Gómez ◽  
Lim Yi ◽  
...  
Keyword(s):  
Deep Learning ◽  
Semantic Segmentation ◽  
High Accuracy ◽  
Experimental Results ◽  
Mobile Mapping ◽  
Mapping System ◽  
Mobile Mapping System ◽  
Reconfigurable Robot ◽  
Nvidia Gpu ◽  
Inspection Task

The pavement inspection task, which mainly includes crack and garbage detection, is essential and carried out frequently. The human-based or dedicated system approach for inspection can be easily carried out by integrating with the pavement sweeping machines. This work proposes a deep learning-based pavement inspection framework for self-reconfigurable robot named Panthera. Semantic segmentation framework SegNet was adopted to segment the pavement region from other objects. Deep Convolutional Neural Network (DCNN) based object detection is used to detect and localize pavement defects and garbage. Furthermore, Mobile Mapping System (MMS) was adopted for the geotagging of the defects. The proposed system was implemented and tested with the Panthera robot having NVIDIA GPU cards. The experimental results showed that the proposed technique identifies the pavement defects and litters or garbage detection with high accuracy. The experimental results on the crack and garbage detection are presented. It is found that the proposed technique is suitable for deployment in real-time for garbage detection and, eventually, sweeping or cleaning tasks.

Rapid annealing of Au thin films by micron chevron-shaped laser beam scanning toward growth of single-grain crystal

2021 ◽  
Vol 60 (SB) ◽  
pp. SBBK06
Author(s):  
Anh Hoang Pham ◽  
Naruki Fukunaga ◽  
Wenchang Yeh ◽  
Shigekazu Morito ◽  
Takuya Ohba
Keyword(s):  
Thin Films ◽  
Laser Beam ◽  
Beam Scanning ◽  
Rapid Annealing ◽  
Single Grain ◽  
Au Thin Films ◽  
Laser Beam Scanning
Sign in / Sign up

Export Citation Format

Share Document