scholarly journals Mind the gap: detection and traversability analysis of terrain gaps using LIDAR for safe robot navigation

Robotica ◽  
2013 ◽  
Vol 31 (7) ◽  
pp. 1085-1101 ◽  
Author(s):  
Arnab Sinha ◽  
Panagiotis Papadakis
Keyword(s):  
Principal Component ◽  
Orientation Distribution ◽  
Obstacle Detection ◽  
Search And Rescue ◽  
Range Data ◽  
Morphological Operations ◽  
Urban Search And Rescue ◽  
3 Dimensional ◽  
The Individual ◽  
Car Accident

SUMMARYSafe navigation of robotic vehicles is considered as a key pre-requisite of successful mission operations within highly adverse and unconstrained environments. While there has been extensive research in the perception of positive obstacles, little progress can be accredited to the field of negative obstacles. This paper hypostatizes an elaborative attempt to address the problem of negative obstacle detection and traversability analysis in the form of gaps by processing 3-dimensional range data. The domain of application concerns Urban Search and Rescue scenarios that reflect environments of increased complexity in terms of diverse terrain irregularities. To allow real-time performance and, in turn, timely prevention of unrecoverable robotic states, the proposed approach is based on the application of efficient image morphological operations for noise reduction and border following the detection and grouping of gaps. Furthermore, we reason about gap traversability, a concept that is novel within the field. Traversability assessments are based on features extracted through Principal Component Analysis by exploring the spatial distribution of the interior of the individual gaps or the orientation distribution of the corresponding contour. The proposed approach is evaluated within a realistic scenario of a tunnel car accident site and a challenging outdoor scenario. Using a contemporary Search and Rescue robot, we have performed extensive experiments under various parameter settings that allowed the robot to always detect the real gaps, and either optimally cross over those that were traversable or otherwise avoid them.

scholarly journals Control of a Hierarchical Team of Robots for Urban Search and Rescue

2021 ◽  
Author(s):  
◽  
Thomas Mirko Roehr
Keyword(s):  
Control System ◽  
Low Cost ◽  
Search And Rescue ◽  
Simulation Environment ◽  
Urban Search And Rescue ◽  
Research Teams ◽  
Mapping Algorithm ◽  
Robot Architecture ◽  
The Individual ◽  
Global And Local

<p>Research teams worldwide are researching the application of robots for Urban Search and Rescue (USAR) operations and some are using teams of robots. The Mechatronics Research Group of Victoria University of Wellington is developing a low cost architecture of a team of USAR robots that is hierarchically structured and can operate autonomously. The objective of this thesis is to design the autonomous control system for the proposed architecture. The overall system design and combination of hardware and software solutions needs to be evaluated in a realistic environment. The project could not perform tests in a real environment and developed a realistic simulation environment instead to allow the evaluation of hardware and software constraints. This project successfully developed an incremental mapping algorithm which served as foundation for distributed path planning, and modified an existing navigation approach to cope with the main challenges of 3D operation environments. In order to deal with multiple robots, this thesis applied a centralised control mechanism and a combination of a global and local exploration strategy. This thesis contributes software solutions to operate the low cost robot architecture and identified weaknesses in the design of the middle tier of robots. The individual algorithms, and their combination in a major control system proved to be effective, but not without limitations. Consequently, this thesis suggests solutions to overcome some of these limitations.</p>

scholarly journals Control of a Hierarchical Team of Robots for Urban Search and Rescue

2021 ◽  
Author(s):  
◽  
Thomas Mirko Roehr
Keyword(s):  
Control System ◽  
Low Cost ◽  
Search And Rescue ◽  
Simulation Environment ◽  
Urban Search And Rescue ◽  
Research Teams ◽  
Mapping Algorithm ◽  
Robot Architecture ◽  
The Individual ◽  
Global And Local

<p>Research teams worldwide are researching the application of robots for Urban Search and Rescue (USAR) operations and some are using teams of robots. The Mechatronics Research Group of Victoria University of Wellington is developing a low cost architecture of a team of USAR robots that is hierarchically structured and can operate autonomously. The objective of this thesis is to design the autonomous control system for the proposed architecture. The overall system design and combination of hardware and software solutions needs to be evaluated in a realistic environment. The project could not perform tests in a real environment and developed a realistic simulation environment instead to allow the evaluation of hardware and software constraints. This project successfully developed an incremental mapping algorithm which served as foundation for distributed path planning, and modified an existing navigation approach to cope with the main challenges of 3D operation environments. In order to deal with multiple robots, this thesis applied a centralised control mechanism and a combination of a global and local exploration strategy. This thesis contributes software solutions to operate the low cost robot architecture and identified weaknesses in the design of the middle tier of robots. The individual algorithms, and their combination in a major control system proved to be effective, but not without limitations. Consequently, this thesis suggests solutions to overcome some of these limitations.</p>

scholarly journals Content-Based Estimation of Brain MRI Tilt in Three Orthogonal Directions

2021 ◽  
Author(s):  
Pooja Prabhu ◽  
A. K. Karunakar ◽  
Sanjib Sinha ◽  
N. Mariyappa ◽  
G. K. Bhargava ◽  
...  
Keyword(s):  
Large Scale ◽  
Brain Mri ◽  
Similarity Measures ◽  
Principal Component ◽  
Brain Anatomy ◽  
Morphological Operations ◽  
Mr Images ◽  
Tilt Correction ◽  
Brain Mr Images ◽  
The Brain

AbstractIn a general scenario, the brain images acquired from magnetic resonance imaging (MRI) may experience tilt, distorting brain MR images. The tilt experienced by the brain MR images may result in misalignment during image registration for medical applications. Manually correcting (or estimating) the tilt on a large scale is time-consuming, expensive, and needs brain anatomy expertise. Thus, there is a need for an automatic way of performing tilt correction in three orthogonal directions (X, Y, Z). The proposed work aims to correct the tilt automatically by measuring the pitch angle, yaw angle, and roll angle in X-axis, Z-axis, and Y-axis, respectively. For correction of the tilt around the Z-axis (pointing to the superior direction), image processing techniques, principal component analysis, and similarity measures are used. Also, for correction of the tilt around the X-axis (pointing to the right direction), morphological operations, and tilt correction around the Y-axis (pointing to the anterior direction), orthogonal regression is used. The proposed approach was applied to adjust the tilt observed in the T1- and T2-weighted MR images. The simulation study with the proposed algorithm yielded an error of 0.40 ± 0.09°, and it outperformed the other existing studies. The tilt angle (in degrees) obtained is ranged from 6.2 ± 3.94, 2.35 ± 2.61, and 5 ± 4.36 in X-, Z-, and Y-directions, respectively, by using the proposed algorithm. The proposed work corrects the tilt more accurately and robustly when compared with existing studies.

Urban Search and Rescue with Anti-pheromone Robot Swarm architecture

2021 ◽  
Author(s):  
Ruben Martin Garcia ◽  
Daniel Hernandez de la Iglesia ◽  
Juan F. de Paz ◽  
Valderi R. Q. Leithardt ◽  
Gabriel Villarrubia
Keyword(s):  
Search And Rescue ◽  
Urban Search And Rescue ◽  
Robot Swarm

scholarly journals Toward a Fully Autonomous UAV: Research Platform for Indoor and Outdoor Urban Search and Rescue

2012 ◽  
Vol 19 (3) ◽  
pp. 46-56 ◽  
Author(s):  
Teodor Tomic ◽  
Korbinian Schmid ◽  
Philipp Lutz ◽  
Andreas Domel ◽  
Michael Kassecker ◽  
...  
Keyword(s):  
Search And Rescue ◽  
Urban Search And Rescue ◽  
Research Platform ◽  
Indoor And Outdoor

scholarly journals Bioactive Phenolic Metabolites from Adriatic Brown Algae Dictyota dichotoma and Padina pavonica (Dictyotaceae)

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1187
Author(s):  
Ivana Generalić Mekinić ◽  
Vida Šimat ◽  
Viktorija Botić ◽  
Anita Crnjac ◽  
Marina Smoljo ◽  
...  
Keyword(s):  
Total Phenolics ◽  
Antioxidant Activities ◽  
Principal Component ◽  
Ultrasound Assisted Extraction ◽  
Antioxidant Power ◽  
Dictyota Dichotoma ◽  
Assisted Extraction ◽  
Sample Data ◽  
Ferric Reducing Antioxidant Power ◽  
The Individual

In this study, the influences of temperature (20, 40 and 60 °C) and extraction solvents (water, ethanol) on the ultrasound-assisted extraction of phenolics from the Adriatic macroalgae Dictyota dichotoma and Padina pavonica were studied. The extracts were analysed for major phenolic sub-groups (total phenolics, flavonoids and tannins) using spectrometric methods, while the individual phenolics were detected by HPLC. The antioxidant activities were evaluated using three methods: Ferric Reducing/Antioxidant Power (FRAP), scavenging of the stabile 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and Oxygen Radical Antioxidant Capacity (ORAC). The aim of the study was also to find the connection between the chemical composition of the extracts and their biological activity. Therefore, principal component analysis (PCA), which permits simple representation of different sample data and better visualisation of their correlations, was used. Higher extraction yields of the total phenolics, flavonoids and tannins were obtained using an alcoholic solvent, while a general conclusion about the applied temperature was not established. These extracts also showed good antioxidant activity, especially D. dichotoma extracts, with high reducing capacity (690–792 mM TE) and ORAC values (38.7–40.8 mM TE in 400-fold diluted extracts). The PCA pointed out the significant influence of flavonoids and tannins on the investigated properties. The results of this investigation could be interesting for future studies dealing with the application of these two algae in foods, cosmetics and pharmaceuticals.

Mobile Robotic Issues for Urban Search and Rescue

2008 ◽  
Vol 41 (2) ◽  
pp. 3098-3103 ◽  
Author(s):  
Gurvinder S. Virk ◽  
Yiannis Gatsoulis ◽  
Mudassir Parack ◽  
Afsha Kherada
Keyword(s):  
Search And Rescue ◽  
Urban Search And Rescue

Unmanned aerial systems (UAS) in urban search and rescue-methodology, capacity development, and integration

2021 ◽  
Vol 19 (1) ◽  
pp. 33-38
Author(s):  
Ariel Braverman, BSc, RN, EMT-P
Keyword(s):  
Situational Awareness ◽  
Search And Rescue ◽  
Unmanned Aerial Systems ◽  
Urban Search And Rescue ◽  
Emergency Operations ◽  
Ventilation Ducts ◽  
Speed Up ◽  
Modernization Process ◽  
Roadless Areas ◽  
Aerial Systems

This paper’s purpose is to establish a methodological basis for using unmanned aerial vehicles (UAV) in urban search and rescue (USAR). Modern USAR operations involve the location, rescue (extrication), and initial medical stabilization of individuals trapped in confined spaces or places with complicated access, eg, high structures. As a part of the ongoing modernization process, this paper explores possible options for UAV utilization in USAR operations. Today, UAV are already taking part in support emergency operations all over the world, and possible forms of operation for UAV in USAR environment can be in two primary modes: on-site and logistic chain. The on-site mode includes various capabilities of multilayer UAV array, mostly based on enhanced visual capabilities to create situational awareness and to speed-up search and rescue (SAR) process including using nanodrones for entering into confined places, ventilation ducts, and underground sewer channels can give to rescue teams’ opportunities to have eyes within ruins even before initial clearing process. Cargo drones will be able to bring equipment directly to high floors or roadless areas in comparison to wheeled transportation. The advantages of cargo drones operation are the ability of autonomous flight based on GPS or homing beacon and ability to provide logistics supports without involving additional personnel and vehicles and with no dependence on road conditions.

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