Search results for "ComputerApplications_COMPUTERSINOTHERSYSTEMS"
showing 10 items of 254 documents
Automotive Radar in a UAV to Assess Earth Surface Processes and Land Responses
2020
The use of unmanned aerial vehicles (UAVs) in earth science research has drastically increased during the last decade. The reason being innumerable advantages to detecting and monitoring various environmental processes before and after certain events such as rain, wind, flood, etc. or to assess the current status of specific landforms such as gullies, rills, or ravines. The UAV equipped sensors are a key part to success. Besides commonly used sensors such as cameras, radar sensors are another possibility. They are less known for this application, but already well established in research. A vast number of research projects use professional radars, but they are expensive and difficult to hand…
A unified vegetation index for quantifying the terrestrial biosphere
2021
[EN] Empirical vegetation indices derived from spectral reflectance data are widely used in remote sensing of the biosphere, as they represent robust proxies for canopy structure, leaf pigment content, and, subsequently, plant photosynthetic potential. Here, we generalize the broad family of commonly used vegetation indices by exploiting all higher-order relations between the spectral channels involved. This results in a higher sensitivity to vegetation biophysical and physiological parameters. The presented nonlinear generalization of the celebrated normalized difference vegetation index (NDVI) consistently improves accuracy in monitoring key parameters, such as leaf area index, gross prim…
TOWARDS SMART MANUFACTURING WITH VIRTUAL FACTORY AND DATA ANALYTICS
2017
International audience; Virtual factory models can help improve manufacturing decision making when augmented with data analytics applications. Virtual factory models provide the capability of simulating real factories and generating realistic data streams at the desired level of resolution. Deeper insights can be gained and underlying relationships quantified by channeling the simulation output data to an external analytics tool. This paper describes integration of a virtual factory prototype with a neural network analytics application. The combined capability is used to create a neural network capable of predicting the expected cycle times for a small job shop. The capability can adapt by …
Minimal-model for robust control design of large-scale hydraulic machines
2018
Hydraulic machines are in use where the large forces, at relatively low velocities, are required by varying loads and often hazardous and hard-to-reach environments, like e.g. offshore, mining, forestry, cargo logistics, and others industries. Cranes and excavators equipped with multiple hydraulic cylinders are typical examples for that. For design of the robust feedback controls of hydraulic cylinders, already installed into large-scale machines, there is a general lack of reliable dynamic models. Also the suitable and feasible identification techniques, especially in frequency domain, yield limited. This paper proposes a minimal-modeling approach for determining the most relevant open-lo…
Vision based attitude and altitude estimation for UAVs in dark environments
2011
This paper presents a system dedicated to the real-time estimation of attitude and altitude for unmanned aerial vehicles (UAV) under low light and dark environment. This system consists in a fisheye camera, which allows to cover a large field of view (FOV), and a laser circle projector mounted on a fixed baseline. The approach, close to structured light systems, uses the geometrical information obtained by the projection of the laser circle onto the ground plane and perceived by the camera. We present a theoretical study of the system in which the camera is modelled as a sphere and show that the estimation of a conic on this sphere allows to obtain the attitude and the altitude of the robot…
Omnidirectional vision for UAV: applications to attitude, motion and altitude estimation for day and night conditions
2012
International audience; This paper presents the combined applications of omnidirectional vision featuring on its application to aerial robotics. Omnidirectional vision is first used to compute the attitude, altitude and motion not only in rural environment but also in the urban space. Secondly, a combination of omnidirectional and perspective cameras permits to estimate the altitude. Finally we present a stereo system consisting of an omnidirectional camera with a laser pattern projector enables to calculate the altitude and attitude during the improperly illuminated conditions to dark environments. We demonstrate that omnidirectional camera in conjunction with other sensors is suitable cho…
Anti-swing control of a hydraulic loader crane with a hanging load
2021
Abstract In this paper, anti-swing control for a hydraulic loader crane is presented. The difference between hydraulic and electric cranes are discussed to show the challenges associated with hydraulic actuation. The hanging load dynamics and relevant kinematics of the crane are derived to create the 2-DOF anti-swing controller. The anti-swing controller is added to the electro-hydraulic motion controller via feedforward. A dynamic simulation model of the crane is made, and the control system is evaluated in simulations with a path controller in actuator space. Simulation results show significant reduction in the load swing angle during motion. Experiments are carried out to verify the perf…
Modular Contact-Free Conveyors for Handling Planar Fragile Objects
2017
Recent studies show that the handling of thin wafers in the photovoltaic industry can lead to unacceptable yields due to cell scratching and breaking. This paper presents the concept and design of a novel modular conveyor that is intended for handling planar fragile objects at a high speed without contact. Each element of the conveyor is a square block that is able to generate tilted air jets that lift and push the object in a single direction. Various handling functions can thus be achieved by the assembly of several blocks. To manage the complexity of assembling systems composed of hundreds of blocks, an automatized design methodology is proposed. This process gives the best topology of t…
A Self-Contained Electro-Hydraulic Cylinder with Passive Load-Holding Capability
2019
Self-contained electro-hydraulic cylinders have the potential to replace both conventional hydraulic systems and the electro-mechanical counterparts enhancing energy efficiency, plug-and-play installation, and reduced maintenance. Current commercial solutions of this technology are limited and typically tailor-made, whereas the research emphasis is primarily on cost efficiency and power applications below five [kW]. Therefore, there is the need of developing more flexible systems adaptable to multiple applications. This research paper offers a contribution in this regard. It presents an electro-hydraulic self-contained single-rod cylinder with passive load-holding capability, sealed tank, c…
A Comparison Study of a Novel Self-Contained Electro-Hydraulic Cylinder versus a Conventional Valve-Controlled Actuator—Part 2: Energy Efficiency
2019
This research paper presents the second part of a comparative analysis of a novel self-contained electro-hydraulic cylinder with passive load-holding capability against a state of the art, valve-controlled hydraulic system that is typically used in load-carrying applications. After addressing the control design and motion performance in the first part of the study, the comparison is now focused on the systems&rsquo