13,824 research outputs found
Computer aided inspection procedures to support smart manufacturing of injection moulded components
This work presents Reverse Engineering and Computer Aided technologies to improve the inspection of injection moulded electro-mechanical parts. Through a strong integration and automation of these methods, tolerance analysis, acquisition tool-path optimization and data management are performed. The core of the procedure concerns the automation of the data measure originally developed through voxel-based segmentation. This paper discusses the overall framework and its integration made according to Smart Manufacturing requirements. The experimental set-up, now in operative conditions at ABB SACE, is composed of a laser scanner installed on a CMM machine able to measure components with lengths in the range of 5÷250 mm, (b) a tool path optimization procedure and (c) a data management both developed as CAD-based applications
Towards Automatic SAR-Optical Stereogrammetry over Urban Areas using Very High Resolution Imagery
In this paper we discuss the potential and challenges regarding SAR-optical
stereogrammetry for urban areas, using very-high-resolution (VHR) remote
sensing imagery. Since we do this mainly from a geometrical point of view, we
first analyze the height reconstruction accuracy to be expected for different
stereogrammetric configurations. Then, we propose a strategy for simultaneous
tie point matching and 3D reconstruction, which exploits an epipolar-like
search window constraint. To drive the matching and ensure some robustness, we
combine different established handcrafted similarity measures. For the
experiments, we use real test data acquired by the Worldview-2, TerraSAR-X and
MEMPHIS sensors. Our results show that SAR-optical stereogrammetry using VHR
imagery is generally feasible with 3D positioning accuracies in the
meter-domain, although the matching of these strongly hetereogeneous
multi-sensor data remains very challenging. Keywords: Synthetic Aperture Radar
(SAR), optical images, remote sensing, data fusion, stereogrammetr
Integration of LIDAR and IFSAR for mapping
LiDAR and IfSAR data is now widely used for a number of applications, particularly those needing a digital elevation model. The data is often complementary to other data such as aerial imagery and high resolution satellite data. This paper will review the current data sources and the products and then look at the ways in which the data can be integrated for particular applications. The main
platforms for LiDAR are either helicopter or fixed wing aircraft, often operating at low altitudes, a digital camera is frequently included on the platform, there is an interest in using other sensors such as 3 line cameras of hyperspectral scanners. IfSAR is used from satellite platforms, or from aircraft, the latter are more compatible with LiDAR for integration. The paper will examine the advantages and disadvantages of LiDAR and IfSAR for DEM generation and discuss the issues which still need to be dealt with. Examples of applications will be given and particularly those involving the integration of different types of data. Examples will be given from various sources and future trends examined
Progress in industrial photogrammetry by means of markerless solutions
174 p.La siguiente tesis está enfocada al desarrollo y uso avanzado de metodologÃas fotogramétrica sin dianas en aplicaciones industriales. La fotogrametrÃa es una técnica de medición óptica 3D que engloba múltiples configuraciones y aproximaciones. En este estudio se han desarrollado procedimientos de medición, modelos y estrategias de procesamiento de imagen que van más allá que la fotogrametrÃa convencional y buscan el emplear soluciones de otros campos de la visión artificial en aplicaciones industriales. Mientras que la fotogrametrÃa industrial requiere emplear dianas artificiales para definir los puntos o elementos de interés, esta tesis contempla la reducción e incluso la eliminación de las dianas tanto pasivas como activas como alternativas prácticas. La mayorÃa de los sistemas de medida utilizan las dianas tanto para definir los puntos de control, relacionar las distintas perspectivas, obtener precisión, asà como para automatizar las medidas. Aunque en muchas situaciones el empleo de dianas no sea restrictivo existen aplicaciones industriales donde su empleo condiciona y restringe considerablemente los procedimientos de medida empleados en la inspección. Un claro ejemplo es la verificación y control de calidad de piezas seriadas, o la medición y seguimiento de elementos prismáticos relacionados con un sistema de referencia determinado. Es en este punto donde la fotogrametrÃa sin dianas puede combinarse o complementarse con soluciones tradicionales para tratar de mejorar las prestaciones actuales
Mapping of Aedes albopictus abundance at a local scale in Italy
Given the growing risk of arbovirus outbreaks in Europe, there is a clear need to better
describe the distribution of invasive mosquito species such as Aedes albopictus. Current challenges
consist in simulating Ae. albopictus abundance, rather than its presence, and mapping its simulated
abundance at a local scale to better assess the transmission risk of mosquito-borne pathogens
and optimize mosquito control strategy. During 2014–2015, we sampled adult mosquitoes using
72 BG-Sentinel traps per year in the provinces of Belluno and Trento, Italy. We found that the sum of
Ae. albopictus females collected during eight trap nights from June to September was positively related
to the mean temperature of the warmest quarter and the percentage of artificial areas in a 250 m
buffer around the sampling locations. Maps of Ae. albopictus abundance simulated from the most
parsimonious model in the study area showed the largest populations in highly artificial areas with
the highest summer temperatures, but with a high uncertainty due to the variability of the trapping
collections. Vector abundance maps at a local scale should be promoted to support stakeholders and
policy-makers in optimizing vector surveillance and control
Ground Profile Recovery from Aerial 3D LiDAR-based Maps
The paper presents the study and implementation of the ground detection
methodology with filtration and removal of forest points from LiDAR-based 3D
point cloud using the Cloth Simulation Filtering (CSF) algorithm. The
methodology allows to recover a terrestrial relief and create a landscape map
of a forestry region. As the proof-of-concept, we provided the outdoor flight
experiment, launching a hexacopter under a mixed forestry region with sharp
ground changes nearby Innopolis city (Russia), which demonstrated the
encouraging results for both ground detection and methodology robustness.Comment: 8 pages, FRUCT-2019 conferenc
2Fly with RPi - Evaluating Suitability of the Raspberry Pi3 B Single Board Computer for Experimental Glass Cockpit Embedded Applications
Computer based cockpits typically interact with the pilot through glass covered displays, and are called glass cockpits. Glass cockpits came first to military aircraft and then to commercial aircraft. Most recently, they have become available for general aviation aircraft. However, price remains a significant barrier for low cost aircraft. At the same time, the price of computers suitable for embedded applications has dropped precipitously. The Raspberry Pi 3B is an example of just such a computer, and can be purchased for 40. This paper seeks to evaluate the suitability of this single board computer for use in an experimental glass cockpit solution. The required functionality of such a solution is detailed – both in term of functionality and in terms of internal workings. The Raspberry Pi 3B computer is then evaluated for potential suitability to drive such a solution. This evaluation is based on mathematical analysis and on the experiences of the world’s hacking community – which has embraced the Raspberry Pi with open arms. Finally, the paper discuses programming techniques and software that the author has evaluated for creating such an experimental glass cockpit. It is the author’s hope that this solution can be implemented in the near future, and that 2Fly with RPi becomes a fully functional open source experimental aircraft situational awareness aid
2Fly with RPi - Evaluating the Raspberry Pi for Glass Cockpit Applications
Evaluating the capabilities of Raspberry Pi computers to be used in embedded glass cockpit applications for experimental aircraft. This includes details of what is required for these applications as well as how well the Raspberry Pi 3B can perform in this role
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