Preliminary Study on Automated Concrete Bridge Inspection

2014 ◽  
Author(s):  
Hermes Giberti ◽  
Andrea Zanoni ◽  
Marco Mauri ◽  
Massimo Gammino
Keyword(s):  
Tracking System ◽  
Laser Scanner ◽  
Field Tests ◽  
Electronic System ◽  
Concrete Bridge ◽  
University Campus ◽  
Bridge Inspection ◽  
3D Geometry ◽  
General Goal ◽  
And Control

This work focuses on the development of a methodology for the complete reconstruction of the 3D geometry of a concrete bridge. 3D scanning technology was selected as the most apt to the task as it provides very detailed geometrical informations. A dedicated carriage system for a compact and lightweight laser scanner has been designed and built as a first prototype to be used on laboratory as well as future on-field tests. A first assessment of the design constraints has been carried out, based on the general goal of implementing a system able to be used with existing inspection vehicles with minimal modifications. The specific electronic system for management and control of the carriage system and the management of the associated tracking system has been also designed and realized. Some preliminary tests have been performed at Politecnico di Milano University campus to assess the viability and analyze the performance of the early design choices.

scholarly journals Optimization of the Bi-Axial Tracking System for a Photovoltaic Platform

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 535
Author(s):  
Cătălin Alexandru
Keyword(s):  
Computer Aided Design ◽  
Tracking System ◽  
Control Device ◽  
Computer Applications ◽  
Optimization Study ◽  
Solar Tracker ◽  
Diurnal Movement ◽  
Multi Body ◽  
Aided Design ◽  
And Control

The article deals with the optimization of the azimuthal tracking mechanism for a photovoltaic (PV) platform, which uses linear actuators as actuation elements for both movements (diurnal and elevation). In the case of diurnal movement, where the platform’s angular field of orientation is large, a mechanism with a relatively simple structure is used for amplifying the actuator’s stroke and avoiding the risk of the system locking itself (by limiting the values of the transmission angle). The optimization study targets the mechanical device, the control device, and the bi-axial tracking program (embodied by the laws of motion in time for the platform’s diurnal and elevation angles) with the purpose of obtaining a high input of solar radiation, with a minimal energy consumption to achieve tracking. The study is carried out by using a virtual prototyping platform, which includes Computer Aided Design (CAD), Multi-Body Systems (MBS), and Design for Control (DFC) computer applications. The mechanical and control devices of the solar tracker are integrated and tested in mechatronic concept. The simulations’ results, which were performed for a set of representative days throughout the year, prove the effectiveness of the proposed design.

scholarly journals Sensor-Based Safety Performance Assessment of Individual Construction Workers

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3897 ◽  
Author(s):  
JeeWoong Park ◽  
Yong K. Cho ◽  
Ali Khodabandelu
Keyword(s):  
Risk Model ◽  
Tracking System ◽  
Field Tests ◽  
Safety Performance ◽  
Worker Safety ◽  
Well Test ◽  
Construction Sites ◽  
Monitoring Method ◽  
Safety Issues ◽  
Automated Method

Over the last decade, researchers have explored various technologies and methodologies to enhance worker safety at construction sites. The use of advanced sensing technologies mainly has focused on detecting and warning about safety issues by directly relying on the detection capabilities of these technologies. Until now, very little research has explored methods to quantitatively assess individual workers’ safety performance. For this, this study uses a tracking system to collect and use individuals’ location data in the proposed safety framework. A computational and analytical procedure/model was developed to quantify the safety performance of individual workers beyond detection and warning. The framework defines parameters for zone-based safety risks and establishes a zone-based safety risk model to quantify potential risks to workers. To demonstrate the model of safety analysis, the study conducted field tests at different construction sites, using various interaction scenarios. Probabilistic evaluation showed a slight underestimation and overestimation in certain cases; however, the model represented the overall safety performance of a subject quite well. Test results showed clear evidence of the model’s ability to capture safety conditions of workers in pre-identified hazard zones. The developed approach presents a way to provide visualized and quantified information as a form of safety index, which has not been available in the industry. In addition, such an automated method may present a suitable safety monitoring method that can eliminate human deployment that is expensive, error-prone, and time-consuming.

scholarly journals Assessment of the Accuracy of a Multi-Beam LED Scanner Sensor for Measuring Olive Canopies

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4406 ◽  
Author(s):  
Rafael Sola-Guirado ◽  
Sergio Bayano-Tejero ◽  
Antonio Rodríguez-Lizana ◽  
Jesús Gil-Ribes ◽  
Antonio Miranda-Fuentes
Keyword(s):  
Laboratory Test ◽  
Real Time ◽  
Relative Error ◽  
Laser Scanner ◽  
Field Tests ◽  
High Accuracy ◽  
Field Conditions ◽  
Canopy Trees ◽  
Canopy Volume

Canopy characterization has become important when trying to optimize any kind of agricultural operation in high-growing crops, such as olive. Many sensors and techniques have reported satisfactory results in these approaches and in this work a 2D laser scanner was explored for measuring canopy trees in real-time conditions. The sensor was tested in both laboratory and field conditions to check its accuracy, its cone width, and its ability to characterize olive canopies in situ. The sensor was mounted on a mast and tested in laboratory conditions to check: (i) its accuracy at different measurement distances; (ii) its measurement cone width with different reflectivity targets; and (iii) the influence of the target’s density on its accuracy. The field tests involved both isolated and hedgerow orchards, in which the measurements were taken manually and with the sensor. The canopy volume was estimated with a methodology consisting of revolving or extruding the canopy contour. The sensor showed high accuracy in the laboratory test, except for the measurements performed at 1.0 m distance, with 60 mm error (6%). Otherwise, error remained below 20 mm (1% relative error). The cone width depended on the target reflectivity. The accuracy decreased with the target density.

IMPROVED PERFORMANCE PHASE DETECTOR FOR MULTIPLICATIVE SECOND-ORDER PLL SYSTEMS USING DEFORMED ALGEBRA

2014 ◽  
Vol 23 (01) ◽  
pp. 1450008
Author(s):  
MARCONI O. DE ALMEIDA ◽  
EDUARDO T. F. SANTOS ◽  
JOSÉ M. ARAÚJO
Keyword(s):  
Control Systems ◽  
Tracking System ◽  
Phase Detector ◽  
Phase Locked Loops ◽  
Frequency Tracking ◽  
Maximum Likelihood Approach ◽  
Multiplicative Type ◽  
Likelihood Approach ◽  
Improved Performance ◽  
And Control

Phase-locked loops (PLL) is a phase and/or frequency tracking system, widely used in communication and control systems. The sinusoidal multiplicative type PLL still remains a recurrent model, due the fact that its derivation is originated from the maximum likelihood approach. In this note, it is showed as a generalized product, called q-product, which can be used to implement the phase detector and improve some important parameters of the PLL system, as the block linearity and pull-in characteristics. Numerical examples are presented in order to illustrate the proposal.

STATIC AND DYNAMIC PERFORMANCE EVALUATION OF A PRE-STRESSED CONCRETE BRIDGE THROUGH FIELD TESTING AND MONITORING

2009 ◽  
Vol 09 (04) ◽  
pp. 711-728 ◽  
Author(s):  
C. S. CAI ◽  
M. ARAUJO ◽  
A. NAIR ◽  
X. SHI
Keyword(s):  
Quantitative Methods ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Field Tests ◽  
Field Measurements ◽  
Field Testing ◽  
Concrete Bridge ◽  
Bridge Structures ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper presents field tests performed on a slab-on-girder pre-stressed concrete bridge. The bridge was tested under static loading, crawling loading, and dynamic loading. A full three-dimensional finite element prediction under both static and dynamic loadings was carried out and the results were compared with the field measurements. While acoustic emission (AE) monitoring of bridge structures is not a new vista, the method has not been fully exploited in bridge monitoring. Though numerous quantitative methods have been proposed, they have not yet developed to be useful for actual field tests of bridges. Therefore, in this study, an attempt was made to use the intensity analysis technique for damage quantification using the AE method.

Effect of a Supervised Stretching Program on Neck, Shoulder, and Trunk Range of Motion in Older Women

2021 ◽  
pp. 1-7
Author(s):  
Sandra C. Webber ◽  
Michelle M. Porter
Keyword(s):  
Range Of Motion ◽  
Older Women ◽  
Intervention Group ◽  
Field Tests ◽  
Community Dwelling ◽  
Upper Body ◽  
Lower Body ◽  
Power Training ◽  
And Control ◽  
Lower Body Power

Abstract Upper body and neck range of motion (ROM) are important for safe walking and driving. The purpose of this study was to determine whether stretching would improve neck, trunk, and shoulder ROM. Forty-eight community-dwelling women (75 ± 3 years of age) were randomly allocated to intervention (upper body stretching, n = 15) and control conditions (lower body power training, n = 33). All participants exercised in supervised 45-minute sessions twice weekly for 12 weeks. Testing of upper body ROM included a cervical ROM, device-based measurement and field tests of the neck, trunk, and shoulder ranges. Shoulder ROM was the only movement that improved in the intervention group beyond levels seen in control participants (33% increase, p < 0.01). Neck and trunk ROM did not change in response to a specific stretching program. Older adults with ROM limitations may need to explore other exercise options or focus on compensatory strategies for safe community mobility.

Effects of an External Nasal Dilator on Athletic Performance of Male Adolescents

2004 ◽  
Vol 29 (5) ◽  
pp. 579-589 ◽  
Author(s):  
Duncan J. Macfarlane ◽  
Stanley K. K. Fong
Keyword(s):  
Effect Size ◽  
Performance Enhancement ◽  
Anaerobic Power ◽  
Field Tests ◽  
Aerobic Performance ◽  
Placebo Condition ◽  
Male Adolescents ◽  
And Control ◽  
Breathing Effort

This study examined the effect of an external nasal dilator strip (ENDS) on three field tests of maximal performance and monitored the rating of perceived breathing effort (RPBE). Thirty male Chinese students (age 15.2 ± 1.6 yrs) performed three maximal field tests: (a) short-term anaerobic power (SAnP: 40-m sprint); (b) long-term anaerobic power (LAnP: shuttle sprint); and (c) peak aerobic performance (AeP: multistage 20-m shuttle run) under three conditions: ENDS, placebo, and control. Students were randomly placed into 6 groups using a fully counterbalanced single-blind design. No significant differences were seen between conditions in the anaerobic performances measured by SAnP and LAnP. However, the ENDS produced a significant improvement in peak aerobic performance (p = 0.037) compared to the control condition of 3.2% (95 %CI = 6.2-0.2; Cohen effect size = 0.2), and also compared to the placebo condition (p = 0.018) of 2.9% (95% CI = 5.1-0.2; Cohen effect size = 0.2). The ENDS condition also significantly reduced RPBE during the AeP and LAnP tests by an average of 5.5% and 3.8%, respectively. Wearing an external nasal dilator can significantly reduce breathing effort and improve peak aerobic performance during field tests involving maximal running. Key words: performance enhancement, nasal strip, oronasal ventilation, perceived breathing effort

An imaging data model for concrete bridge inspection

2004 ◽  
Vol 35 (8-9) ◽  
pp. 473-480 ◽  
Author(s):  
Osama Abudayyeh ◽  
Mohammed Al Bataineh ◽  
Ikhlas Abdel-Qader
Keyword(s):  
Data Model ◽  
Concrete Bridge ◽  
Imaging Data ◽  
Bridge Inspection
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