scholarly journals New Instrumented Trolleys and A Procedure for Automatic 3D Optical Inspection of Railways

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2927
Author(s):  
Maria Cristina Valigi ◽  
Silvia Logozzo ◽  
Enrico Meli ◽  
Andrea Rindi
Keyword(s):  
Optical Sensors ◽  
Experimental Tests ◽  
Software Inspection ◽  
Damage Evaluation ◽  
Optical Scanners ◽  
Optical Scanning ◽  
Optical Inspection ◽  
Wear Evaluation ◽  
Automated Software ◽  
Contact Sensors

This paper focuses on new instrumented trolleys, allowing automated 3D inspection of railway infrastructures, using optical scanning principles and devices for defects and damage evaluation. Inspection of rolling components is crucial for wear evaluation and to schedule maintenance interventions to assure safety. Currently, inspection trolleys are mainly instrumented with 2D contact or optical sensors. The application of 3D non-contact digitizers proposed in this paper allows for a quick and more complete monitoring of the health conditions of railways, also in combination with a proper procedure for automatic 3D inspection. The results of the experimental tests using 3D portable optical scanners on railways are compared with results obtained by a trolley instrumented with 2D contact sensors. The results demonstrate the effectiveness of the trolleys mounting 3D handheld optical digitizers with proper automated software inspection procedures.

Optische Schmelzbadüberwachung*/Optical monitoring of the melting bath in an Al-melting furnace

2018 ◽  
Vol 108 (11-12) ◽  
pp. 760-766
Author(s):  
S. Mohammadifard ◽  
J. Langner ◽  
M. Stonis ◽  
S. Sauke ◽  
H. Larki Harchegani ◽  
...  
Keyword(s):  
Oxide Layer ◽  
Optical Sensors ◽  
Melting Furnace ◽  
Bath Surface ◽  
Optical Monitoring ◽  
Measuring Systems ◽  
Height Change ◽  
First Time ◽  
Contact Sensors ◽  
Holding Temperature

In einem Aluminium (Al)-Schmelzofen sind der Füllstand des Schmelzbades und die Oxidschichtmenge mit Kontaktsensoren nicht überwachbar, da das Schmelzbad aufgrund der hohen Haltebereich-Temperaturen von über 600 °C nicht zugänglich ist. Deshalb wird ein Online-Überwachungssystem des Aluminium-Schmelzbades mithilfe optischer Sensoren erforscht. Dafür wird das Schmelzbad mit geeigneten optischen Messsystemen identifiziert. Schließlich werden durch Bildanalyse-Algorithmen die Höhenänderung der Schmelze herausgearbeitet. Zudem werden Oxidschichten im Ofen auf der Badoberfläche mithilfe der Algorithmen detektiert.   The melt level and oxide layer quantity in an aluminum melting furnace cannot be monitored by contact sensors, since the melting bath is not accessible due to the high holding temperature (above 600 °C). Therefore, the method of monitoring the melting bath by means of optical sensors is investigated for the first time. For this purpose, suitable optical measuring systems can be applied which will be able to record the melting bath. The height change of the melt is to be elaborated by means of image analysis and any oxide layer on the bath surface is to be detected.

scholarly journals A Sterescopic System to Measure Water Waves in Laboratories

2020 ◽  
Vol 12 (14) ◽  
pp. 2288
Author(s):  
Matteo Gianluca Molfetta ◽  
Maria Francesca Bruno ◽  
Luigi Pratola ◽  
Antonio Rinaldi ◽  
Alberto Morea ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Water Waves ◽  
Water Surface ◽  
Ad Hoc ◽  
Experimental Tests ◽  
Automatic Recognition ◽  
Large Wave ◽  
Significant Wave ◽  
New System ◽  
Over Time

A new system for estimating the synthetic parameters of sea states during physical investigations has been implemented. The technique proposed herein is based on stereographic analysis of digital images acquired with optical sensors. A series of ad hoc floating markers has been made and properly moored to the bottom of a large wave tank to estimate the synthetic parameters of generated waves. The implemented acquisition system and the proposed algorithm provide automatic recognition of all markers by a pair of optical sensors that synchronously captures their instantaneous location and tracks their movements over time. After transformation from the image to the real-world coordinates, water surface elevation time series have been obtained. Several experimental tests have been carried out to assess the feasibility and reliability of the proposed approach. The estimated wave synthetic parameters have been then compared with those obtained by employing standard resistive probes. The deviation were found to be equal to ~6% for the significant wave height and 1% for peak, mean, and significant wave periods.

POSSIBILITIES AND LIMITATIONS OF COMBINED SCANNERS

2018 ◽  
pp. 74-82
Author(s):  
V. G. Vyskub
Keyword(s):  
Structural Characteristics ◽  
Optical Beam ◽  
Optical Scanners ◽  
Limit Values ◽  
Optical Scanning ◽  
Effective Combination ◽  
Radiation Sources ◽  
Dynamic Precision ◽  
Application Analysis

The technique of optical scanning is continuously developing in the direction of creating new and improving existing types of scanners (deflectors), radiation sources, methods of reading, converting and reproducing information. However, the absence of universal scanner, able to satisfy different applications leads to necessity of application of combined scanning, finding the most effective combination of deflectors with complementary characteristics taking into account their limit values. The purpose of this work is an overview of a typical combined of the scanners used in the systems of wide application, analysis of existing experience in the use of combined deflectors. The article discusses the optical schemes of modern combined scanners, which include scanners of different operating principles and design. The analysis of combined devices for various applications is given, which included optical-mechanical, electronic, acoustic-optical, electro-optical scanners, as well as micro-electromechanical (MEMS) systems, expanding the sphere of scanning tools. The consideration was conducted with a wide set of parameters and characteristics, such as speed, resolution, accuracy of the control of the optical beam, the size of the scanned space, etc. Identified features and benefits of the combined scanning for dynamic, precision, spectral, and structural characteristics and functionality, and also are noted difficulty in implementing a combined scanning. Among them are optical harmonization, dynamic, algorithmic and precision matching of scanners integrated into the device.

Integrally Bladed Rotor Mistuning Identification and Model Updating Using Geometric Mistuning Models

2020 ◽  
Author(s):  
Joseph A. Beck ◽  
Jeffrey M. Brown ◽  
Daniel L. Gillaugh ◽  
Emily B. Carper ◽  
Alex A. Kaszynski
Keyword(s):  
Elastic Modulus ◽  
Model Updating ◽  
Element Model ◽  
Analytical Models ◽  
Optical Scanners ◽  
Reduced Order ◽  
Optical Scanning ◽  
Numerical Predictions ◽  
Simulated Test ◽  
Bladed Rotor

Abstract Non-uniform manufacturing variations and uneven usage wear and damage, referred to as mistuning, can drastically alter the dynamic response of Integrally Blade Rotors (IBR)s. Optical scanners, combined with Finite Element Model (FEM) mesh metamorphosis algorithms, have provided capabilities to create analytical models that reduce the effect of geometrical uncertainties in numerical predictions. However, deviations in material properties cannot be obtained via optical scanning, so additional approaches are needed. A geometric mistuning Reduced-Order Model (ROM) is developed and modified to solve for unknown IBR sector eigenvalues that are linearly proportional to Elastic modulus. The developed approach accounts for both proportional and non-proportional mistuning and allows updating of the Elastic modulus for each sector in the ROM. Different tuned and mistuned modal reduction procedures are employed to understand the implications of each for identifying mistuning. Simulated test data with known inputs indicate the efficiency and accuracy of the method and improvements over using a traditional, tuned mode approach. The developed methods are then extended to bench-level traveling wave excitation data to discern how sector frequencies vary due to geometry and modulus mistuning.

Optische Schmelzüberwachung*/Optical monitoring of the melting process in an Al-melting furnace

2016 ◽  
Vol 106 (10) ◽  
pp. 738-742
Author(s):  
B.-A. Prof. Behrens ◽  
H. Semrau ◽  
S.-O. Sauke ◽  
H. Larki Harchegani ◽  
S. Mohammadifard
Keyword(s):  
Optical Sensors ◽  
Melting Furnace ◽  
Melting Process ◽  
High Energy ◽  
Measuring System ◽  
Energy Losses ◽  
Optical Monitoring ◽  
Residual Aluminum ◽  
Material State ◽  
Contact Sensors

Durch die hohen Ofentemperaturen ist der Schmelzvorgang in einem Aluminiumschmelzofen nicht durch berührende Sensoren überwachbar. Daher erforscht das IFUM die Überwachung des Schmelzvorgangs mit einem optischen Messsystem, welches die Schmelzbrücke trotz rotglühender Ofenwände aufnehmen kann. Danach arbeitet eine softwaregestützte Bildanalyse der Aufnahmen die Zustände während des Schmelzvorgangs oder die Höhenänderungen des Aluminiums heraus und detektiert Schmelzreste im Ofen auf der Schmelzbrücke, um das mit großen Energieverlusten behaftete Öffnen der Ofentür zur Ermittlung des Restaluminiums im Ofen weitestgehend zu vermeiden.   The melting process in a furnace cannot be monitored by contact sensors due to the high temperatures. Thus, the IFUM investigates a method for monitoring the melting process by optical sensors. An optical measuring system will monitor the fuse bridge despite the red-hot furnace walls. Next, the material state during the melting process or the change in height of the aluminum block is elaborated by an image analysis of the recordings to detect any melt residues on the fuse bridge. Thus, the opening of the furnace door to determine the amount of residual aluminum, which always causes high energy losses, can largely be avoided.

Sensing in the visible spectrum and beyond for terrain estimation in precision agriculture

2017 ◽  
Vol 8 (2) ◽  
pp. 423-429 ◽  
Author(s):  
A. Milella ◽  
M. Nielsen ◽  
G. Reina
Keyword(s):  
Optical Sensors ◽  
Precision Agriculture ◽  
Near Infrared ◽  
Visible Spectrum ◽  
Experimental Tests ◽  
Point Clouds ◽  
Sensor Data ◽  
Spectral Signatures ◽  
3D Point Clouds ◽  
3D Terrain

A multi-sensor approach for terrain estimation is proposed using a combination of complementary optical sensors that cover the visible (VIS), near infrared (NIR) and infrared (IR) spectrum. The sensor suite includes a stereovision sensor, a VIS-NIR camera and a thermal camera, and it is intended to be mounted on board an agricultural vehicle, pointing downward to scan the portion of the terrain ahead. A method to integrate the different sensor data and create a multi-modal dense 3D terrain map is presented. The stereovision input is used to generate 3D point clouds that incorporate RGB-D information, whereas the VIS-NIR camera and the thermal sensor are employed to extract respectively spectral signatures and temperature information, to characterize the nature of the observed surfaces. Experimental tests carried out by an off-road vehicle are presented, showing the feasibility of the proposed approach.

scholarly journals Three-Dimensional Mapping in Underwater Environment

2019 ◽  
Vol 5 (2) ◽  
pp. 10-18
Author(s):  
Alexandra Pereira Nunes ◽  
Aníbal Matos
Keyword(s):  
Optical Sensors ◽  
Autonomous Underwater Vehicles ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Human Beings ◽  
Map Construction ◽  
Optical Inspection ◽  
Three Dimensional Mapping ◽  
Visual Approach ◽  
Real Scenario

Autonomous underwater vehicles are applied in diverse fields, namely in tasks that are risky for human beings to perform, as optical inspection for the purpose of structures quality control. Optical sensors are more appealing cost and they supply a larger quantity of data. Lasers can be used to reconstruct structures in three dimensions, along with cameras, which create a faithful representation of the environment. However, in this context a visual approach was used and the paper presents a method that can put together the three-dimensional information that has been harvested over time, combining also RGB information for surface reconstruction. The map construction follows the motion estimated by a odometry method previously selected from the literature. Experiments conducted using real scenario show that the proposed solution is able to provide a reliable map for objects and even the seafloor.

Integrally Bladed Rotor Mistuning Identification and Model Updating Using Geometric Mistuning Models

2021 ◽  
Author(s):  
Joseph Beck ◽  
Jeffrey Brown ◽  
Daniel Gillaugh ◽  
Emily Carper ◽  
Alex Kaszynski
Keyword(s):  
Elastic Modulus ◽  
Model Updating ◽  
Element Model ◽  
Analytical Models ◽  
Optical Scanners ◽  
Reduced Order ◽  
Optical Scanning ◽  
Numerical Predictions ◽  
Simulated Test ◽  
Bladed Rotor

Abstract Non-uniform manufacturing variations and uneven usage wear and damage, referred to as mistuning, can drastically alter the dynamic response of Integrally Bladed Rotors (IBRs). Optical scanners, combined with Finite Element Model mesh metamorphosis algorithms, have provided capabilities to create analytical models that reduce the effect of geometrical uncertainties in numerical predictions. However, deviations in material properties cannot be obtained via optical scanning, so additional approaches are needed. A geometric mistuning Reduced-Order Model (ROM) is developed and modified to solve for unknown IBR sector eigenvalues that are linearly proportional to Elastic modulus. The developed approach accounts for both proportional and non-proportional mistuning and allows updating of the Elastic modulus for each sector in the ROM. Different tuned and mistuned modal reduction procedures are employed to understand the implications of each for identifying mistuning. Simulated test data with known inputs indicate the efficiency and accuracy of the method and improvements over using a traditional, tuned mode approach. The developed methods are then extended to bench-level traveling wave excitation data to discern how sector frequencies vary due to geometry and modulus mistuning.

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