Automatic large-scale three dimensional modeling using cooperative multiple robots

Abstract3D modeling of real objects by a 3D laser scanner has become popular in many applications, such as reverse engineering of petrochemical plants, civil engineering and construction, and digital preservation of cultural properties. Despite the development of lightweight and high-speed laser scanners, the complicated measurement procedure and long measurement time are still heavy burdens for widespread use of laser scanning. To solve these problems, a robotic 3D scanning system using multiple robots has been proposed. This system, named CPS-SLAM, consists of a parent robot with a 3D laser scanner and child robots with target markers. A large-scale 3D model is acquired by an on-board 3D laser scanner on the parent robot from several positions determined precisely by a localization technique, named the Cooperative Positioning System (CPS), that uses multiple robots. Therefore, this system can build a 3D model without complicated post-processing procedures such as ICP. In addition, this system is an open-loop SLAM system and a very precise 3D model can be obtained without closed loops. This paper proposes an automatic planning technique for a laser measurement by using CPS-SLAM. Planning a proper scanning strategy depending on a target structure makes it possible to perform laser scanning efficiently and accurately even for a large-scale and complex environment. The proposed technique plans an efficient scanning strategy automatically by taking account of several criteria, such as visibility between robots, error accumulation, and efficient traveling. We conducted computer simulations and outdoor experiments to verify the performance of the proposed technique

Fostering Etruscan heritage with effective integration of UAV, TLS and SLAM-based methods

The paper has the main role of highlighting the advantages resulting from the combination of different 3D survey methods and how the approaches that involve data and methods fusion can be advantageous in cases where the environment in which one operates is particularly impervious and not very inclined to be faced with traditional solutions. UAV Photogrammetry, TLS and the innovative 3D scanning based on SLAM technology are combined for the investigation and the documentation of a suggestive landscape and archaeological park. The hand held SLAM based scanner, capable of generating the point cloud travelling among complex indoor and outdoor environments, detecting even small defined spaces, has proved its fundamental importance for the knowledge and reconstruction of the landscape of a particular category of ancient heritage: the necropolis of the caves of the Baratti e Populonia park, which lies in a suggestive scenario of rich and dense forest

Point clouds by SLAM-based mobile mapping systems: accuracy and geometric content validation in multisensor survey and stand-alone acquisition

The paper provides some operative replies to evaluate the effectiveness and the critical issues of the simultaneous localisation and mapping (SLAM)-based mobile mapping system (MMS) called ZEB by GeoSLAM™ https://geoslam.com/technology/. In these last years, this type of handheld 3D mapping technology has increasingly developed the framework of portable solutions for close-range mapping systems that have mainly been devoted to mapping the indoor building spaces of enclosed or underground environments, such as forestry applications and tunnels or mines. The research introduces a set of test datasets related to the documentation of landscape contexts or the 3D modelling of architectural complexes. These datasets are used to validate the accuracy and informative content richness about ZEB point clouds in stand-alone solutions and in cases of combined applications of this technology with multisensor survey approaches. In detail, the proposed validation method follows the fulfilment of the endorsed approach by use of root mean square error (RMSE) evaluation and deviation analysis assessment of point clouds between SLAM-based data and 3D point cloud surfaces computed by more precise measurement methods to evaluate the accuracy of the proposed approach. Furthermore, this study specifies the suitable scale for possible handlings about these peculiar point clouds and uses the profile extraction method in addition to feature analyses such as corner and plane deviation analysis of architectural elements. Finally, because of the experiences reported in the literature and performed in this work, a possible reversal is suggested. If in the 2000s, most studies focused on intelligently reducing the light detection and ranging (LiDAR) point clouds where they presented redundant and not useful information, contrariwise, in this sense, the use of MMS methods is proposed to be firstly considered and then to increase the information only wherever needed with more accurate high-scale methods

Optimization of Three-Dimensional (3D) Multi-Sensor Models For Damage Assessment in Emergency Context: Rapid Mapping Experiences in the 2016 Italian Earthquake

Geomatics techniques offer the chance to manage very cost-effective solutions for three-dimensional (3D) modelling, from both the aerial and terrestrial point of view, with the help of range and image-based sensors. 3D spatial data that is based on integrated documentation techniques, featured by a very high-scale and an accurate metric and radiometric information nowadays are proposed here as metric databases that are applicable for assisting the operative fieldwork in the case of rapid mapping strategies. In sudden emergency contexts for damage and risk assessment, the structural consolidation and the security measures operations meet the problem of the danger and accessibility constraints of areas, for the operators, as well as to the tight deadlines needs in first aid. The use of Unmanned Aerial Vehicles (UAVs) equipped with cameras are more and more involved in aerial survey and reconnaissance missions; at the same time, the ZEB1 portable Light Detection and Ranging (LiDAR) mapping solution implemented in handle tools helped by Simultaneous Localization And Mapping (SLAM) algorithms can help for a quick preliminary survey. Both of these approaches that are presented here in the critical context of a post-seismic event, which is Pescara del Tronto (AP), deeply affected by the 2016-2017 earthquake in Central Italy. The Geomatics research group and the Disaster Recovery team (DIRECT—http://areeweb.polito.it/direct/) is working in collaboration with the Remotely Piloted Aircraft Systems (RPAS) group of the Italian Firefighter

Multi-environment Georeferencing of RGB-D Panoramic Images from Portable Mobile Mapping – a Perspective for Infrastructure Management

Hochaufgelöste, genau georeferenzierte RGB-D-Bilder sind die Grundlage für 3D-Bildräume bzw. 3D Street-View-Webdienste, welche bereits kommerziell für das Infrastrukturmanagement eingesetzt werden. MMS ermöglichen eine schnelle und effiziente Datenerfassung von Infrastrukturen. Die meisten im Aussenraum eingesetzten MMS beruhen auf direkter Georeferenzierung. Diese ermöglicht in offenen Bereichen absolute Genauigkeiten im Zentimeterbereich. Bei GNSS-Abschattung fällt die Genauigkeit der direkten Georeferenzierung jedoch schnell in den Dezimeter- oder sogar in den Meterbereich. In Innenräumen eingesetzte MMS basieren hingegen meist auf SLAM. Die meisten SLAM-Algorithmen wurden jedoch für niedrige Latenzzeiten und für Echtzeitleistung optimiert und nehmen daher Abstriche bei der Genauigkeit, der Kartenqualität und der maximalen Ausdehnung in Kauf. Das Ziel dieser Arbeit ist, hochaufgelöste RGB-D-Bilder in verschiedenen Umgebungen zu erfassen und diese genau und zuverlässig zu georeferenzieren. Für die Datenerfassung wurde ein leistungsstarkes, bildfokussiertes und rucksackgetragenes MMS entwickelt. Dieses besteht aus einer Mehrkopf-Panoramakamera, zwei Multi-Beam LiDAR-Scannern und einer GNSS- und IMU-kombinierten Navigationseinheit der taktischen Leistungsklasse. Alle Sensoren sind präzise synchronisiert und ermöglichen Zugriff auf die Rohdaten. Das Gesamtsystem wurde in Testfeldern mit bündelblockbasierten sowie merkmalsbasierten Methoden kalibriert, was eine Voraussetzung für die Integration kinematischer Sensordaten darstellt. Für eine genaue und zuverlässige Georeferenzierung in verschiedenen Umgebungen wurde ein mehrstufiger Georeferenzierungsansatz entwickelt, welcher verschiedene Sensordaten und Georeferenzierungsmethoden vereint. Direkte und LiDAR SLAM-basierte Georeferenzierung liefern Initialposen für die nachträgliche bildbasierte Georeferenzierung mittels erweiterter SfM-Pipeline. Die bildbasierte Georeferenzierung führt zu einer präzisen aber spärlichen Trajektorie, welche sich für die Georeferenzierung von Bildern eignet. Um eine dichte Trajektorie zu erhalten, die sich auch für die Georeferenzierung von LiDAR-Daten eignet, wurde die direkte Georeferenzierung mit Posen der bildbasierten Georeferenzierung gestützt. Umfassende Leistungsuntersuchungen in drei weiträumigen anspruchsvollen Testgebieten zeigen die Möglichkeiten und Grenzen unseres Georeferenzierungsansatzes. Die drei Testgebiete im Stadtzentrum, im Wald und im Gebäude repräsentieren reale Bedingungen mit eingeschränktem GNSS-Empfang, schlechter Beleuchtung, sich bewegenden Objekten und sich wiederholenden geometrischen Mustern. Die bildbasierte Georeferenzierung erzielte die besten Genauigkeiten, wobei die mittlere Präzision im Bereich von 5 mm bis 7 mm lag. Die absolute Genauigkeit betrug 85 mm bis 131 mm, was einer Verbesserung um Faktor 2 bis 7 gegenüber der direkten und LiDAR SLAM-basierten Georeferenzierung entspricht. Die direkte Georeferenzierung mit CUPT-Stützung von Bildposen der bildbasierten Georeferenzierung, führte zu einer leicht verschlechterten mittleren Präzision im Bereich von 13 mm bis 16 mm, wobei sich die mittlere absolute Genauigkeit nicht signifikant von der bildbasierten Georeferenzierung unterschied. Die in herausfordernden Umgebungen erzielten Genauigkeiten bestätigen frühere Untersuchungen unter optimalen Bedingungen und liegen in derselben Grössenordnung wie die Resultate anderer Forschungsgruppen. Sie können für die Erstellung von Street-View-Services in herausfordernden Umgebungen für das Infrastrukturmanagement verwendet werden. Genau und zuverlässig georeferenzierte RGB-D-Bilder haben ein grosses Potenzial für zukünftige visuelle Lokalisierungs- und AR-Anwendungen

Challenging multi-sensor data models and use of 360 images. The Twelve Months Fountain of Valentino park in Turin

The cultural heritage and the ways in which it is today studied and analysed as well as disseminated and enhanced for the purposes of conservation, requires high attention in the choice of 3D survey and modelling methods. This manuscript investigates the possible integrations and fusion of methods and data, among the vast availability of image and range based systems, especially in the sphere of low cost techniques, which in the context of heritage documentation makes the whole and complex process of conservation more sustainable. The investigation is carried out on a historical fountain that includes a quantity of cultural values and the need to document its context: its location in the historical Valentino of Turin park, its architectural values and the geometry of the complex typically related to the tastes of the late XIX century that consist in the extreme refinement of the statuary complexes and the underground portion with the technological equipment for the activation of the water games. Basically, it will be possible to appreciate solved issues and permanent criticalities derived from the integration of close range and UAV photogrammetry techniques in addition to the LiDAR survey, both classic from a fixed position, and in the portable scanner mode, based on SLAM technology

UAV or Drones for Remote Sensing Applications in GPS/GNSS Enabled and GPS/GNSS Denied Environments

The design of novel UAV systems and the use of UAV platforms integrated with robotic sensing and imaging techniques, as well as the development of processing workflows and the capacity of ultra-high temporal and spatial resolution data, have enabled a rapid uptake of UAVs and drones across several industries and application domains.This book provides a forum for high-quality peer-reviewed papers that broaden awareness and understanding of single- and multiple-UAV developments for remote sensing applications, and associated developments in sensor technology, data processing and communications, and UAV system design and sensing capabilities in GPS-enabled and, more broadly, Global Navigation Satellite System (GNSS)-enabled and GPS/GNSS-denied environments.Contributions include:UAV-based photogrammetry, laser scanning, multispectral imaging, hyperspectral imaging, and thermal imaging;UAV sensor applications; spatial ecology; pest detection; reef; forestry; volcanology; precision agriculture wildlife species tracking; search and rescue; target tracking; atmosphere monitoring; chemical, biological, and natural disaster phenomena; fire prevention, flood prevention; volcanic monitoring; pollution monitoring; microclimates; and land use;Wildlife and target detection and recognition from UAV imagery using deep learning and machine learning techniques;UAV-based change detection

MULTI-SOURCE APPROACHES FOR COMPLEX ARCHITECTURE DOCUMENTATION: THE “PALAZZO DUCALE” IN GUBBIO (PERUGIA, ITALY)

Nowadays, the employment of rapid mapping solutions for architectural survey is more and more considered, not only for the strong reduction of the primary data acquisition times, but also thanks to their adaptability to various contexts, especially in the framework of Cultural Heritage documentation where tailored solutions are required. The combined use of Mobile Mapping Systems (MMS), Unmanned Aerial Vehicles (UAV) for close range aerial image acquisition, and Terrestrial Laser Scanning (TLS) seems to be an effective solution for the architectonic scale compliant to the level of detail and accuracy of 1 : 200, and 1 : 100 scales. The present research tries to evaluate the use of a handheld MMS, the ZEB-Revo RT by Geoslam, an UAV, the DJI Mavic Pro, and a LiDAR system, the Faro Focus3D S 120 by CAM2. The complex case of the documentation metric survey of Palazzo Ducale in Gubbio, the Montefeltro’s Palace, now hosting the museum of itself, allows the comparison of the effectiveness of the used technologies

Robotic autonomous systems for earthmoving equipment operating in volatile conditions and teaming capacity: a survey

Abstract There has been an increasing interest in the application of robotic autonomous systems (RASs) for construction and mining, particularly the use of RAS technologies to respond to the emergent issues for earthmoving equipment operating in volatile environments and for the need of multiplatform cooperation. Researchers and practitioners are in need of techniques and developments to deal with these challenges. To address this topic for earthmoving automation, this paper presents a comprehensive survey of significant contributions and recent advances, as reported in the literature, databases of professional societies, and technical documentation from the Original Equipment Manufacturers (OEM). In dealing with volatile environments, advances in sensing, communication and software, data analytics, as well as self-driving technologies can be made to work reliably and have drastically increased safety. It is envisaged that an automated earthmoving site within this decade will manifest the collaboration of bulldozers, graders, and excavators to undertake ground-based tasks without operators behind the cabin controls; in some cases, the machines will be without cabins. It is worth for relevant small- and medium-sized enterprises developing their products to meet the market demands in this area. The study also discusses on future directions for research and development to provide green solutions to earthmoving.</jats:p

Integrated HBIM-GIS Models for Multi-Scale Seismic Vulnerability Assessment of Historical Buildings

The complexity of historical urban centres progressively needs a strategic improvement in methods and the scale of knowledge concerning the vulnerability aspect of seismic risk. A geographical multi-scale point of view is increasingly preferred in the scientific literature and in Italian regulation policies, that considers systemic behaviors of damage and vulnerability assessment from an urban perspective according to the scale of the data, rather than single building damage analysis. In this sense, a geospatial data sciences approach can contribute towards generating, integrating, and making virtuous relations between urban databases and emergency-related data, in order to constitute a multi-scale 3D database supporting strategies for conservation and risk assessment scenarios. The proposed approach developed a vulnerability-oriented GIS/HBIM integration in an urban 3D geodatabase, based on multi-scale data derived from urban cartography and emergency mapping 3D data. Integrated geometric and semantic information related to historical masonry buildings (specifically the churches) and structural data about architectural elements and damage were integrated in the approach. This contribution aimed to answer the research question supporting levels of knowledge required by directives and vulnerability assessment studies, both about the generative workflow phase, the role of HBIM models in GIS environments and toward user-oriented webGIS solutions for sharing and public use fruition, exploiting the database for expert operators involved in heritage preservation