Search results for "Methodologie"
showing 10 items of 2141 documents
Foundations of offshore wind turbines: A review
2019
Abstract Offshore wind is a source of clean, renewable energy of great potential value to the power industry in the context of a low carbon society. Rapid development of offshore wind energy depends on a good understanding of technical issues related to offshore wind turbines, which is spurring ongoing research and development programmes. Foundations of offshore wind turbines present one of the main challenges in offshore wind turbine design. This paper reviews the present state of knowledge concerning geotechnical and structural issues affecting foundation types under consideration for the support structures of offshore wind turbines, and provides recommendations for future research and de…
Off-line path correction of robotic face milling using static tool force and robot stiffness
2015
In this paper the developed method for off-line compensation of tool deflections when milling aluminum with an industrial robot is presented. The efficiency of this approach is verified with high precision measurements of deflections using a laser tracker. The compensation method includes both the static milling process model which can predict the mean value components of the tool forces and a new combined local/global approach for estimating the combined stiffnesses of joints. With a process model such as the one presented in this paper and estimates of the robot's joint stiffness values, the tool path can be adjusted to counteract deflections of the tool during milling operations. The mod…
Design of a configurable multispectral imaging system based on an AOTF.
2011
In this paper, we present a configurable multispectral imaging system based on an acousto-optic tunable filter (AOTF). Typically, AOTFs are used to filter a single wavelength at a time, but thanks to the use of a versatile sweeping frequency generator implemented with a direct digital synthesizer, the imager may capture a configurable spectral range. Experimental results show a good spectral and imaging response of the system for spectral bandwidth up to a 50 nm.
The metrological characterization of the static meters for reactive energy in the presence of harmonic distortion
2007
For the electricity metering for billing purposes in distribution systems, the static meters are substituting the traditional inductive meters. Thus, the evaluation of the performances of such equipments is required, also in the presence of disturbances affecting the power systems. With respect to this, this paper analyzes the main aspects related to the metrological characterization of the static meters for reactive energy in the presence of harmonic distortion. Particular attention is given to the reference standard meters, that are not considered by the actual in-force Standards. The analysis is supported by several experimental tests.
Static meters for the reactive energy in the presence of harmonics: an experimental metrological characterization
2009
Electricity metering plays a crucial role for all the commercial transactions on the energy market. Thus, an accurate evaluation of the performance of the electricity metering equipment is required not only in the reference operating conditions but also in the presence of disturbances affecting the power systems. As regards this matter, this paper analyzes the main aspects related to the metrological characterization of the static meters for the reactive energy in the presence of harmonic distortion. Attention is focused not only to the meters covered by the current standards but also to the meters of better accuracy and to the reference standard meters. The analysis is supported by several…
The Use of Accelerometers and Gyroscopes to Estimate Hip and Knee Angles on Gait Analysis
2014
In this paper the performance of a sensor system, which has been developed to estimate hip and knee angles and the beginning of the gait phase, have been investigated. The sensor system consists of accelerometers and gyroscopes. A new algorithm was developed in order to avoid the error accumulation due to the gyroscopes drift and vibrations due to the ground contact at the beginning of the stance phase. The proposed algorithm have been tested and compared to some existing algorithms on over-ground walking trials with a commercial device for assisted gait. The results have shown the good accuracy of the angles estimation, also in high angle rate movement.
Multicolour LEDs in educational demonstrations of physics and optometry
2014
LED light sources are used to design experimental setup for university courses teaching human color vision. The setup allows to demonstrate various vision characteristics and to apply for student practical exercises to study eye spectral sensitivity in different spectral range using heterochromatic flicker photometry. Technique can be used in laboratory works for students to acquire knowledge in visual perception, basics of electronics and measuring, or it can be applied as fully computer control experiment. Besides studies of the eye spectral sensitivity students can practice in trichromatic color matching and other visual perception tasks
A Correlation Retina in Standard 0.6um : Application in Positioning System
2003
International audience; We have designed and fabricated a programmable retina that is capable of recognizing patterns stored in memory in real-time. Each of the pixels of the retina is composed of a photodiode and an electronic device used during the programming phase to digitize the image of the pattern to recognize into a binary image stored in latches. The array of pixels is thus partitioned into two complementary disjoint sub-sets with all the photodiodes of the same sub-set connected together in order to obtain the sum total of the currents. During the analysis phase, an optical correlation between the projected image and the reference binary image memorized in the circuit is done. The…
A New Method to Measure 3D Textile Defects by Using Dual-lens Camera
2013
International audience; Industrial textile fabric with functionalization always has a high standard requirement. Take polytetrafluoroethylene (PTFE) conveyor belt as an example, the base fabrics must be of first-rate quality, with no weaving faults or broken fibers on coated surface [1]. In a previous work, we have proposed an original method to measure the height of the fiber based on variable homography. This measurement is based on a single camera acquiring two successive frames. This scheme is working well, but measurement depends on conveyor speed used for scrolling fabric. In this paper, we propose an improvement by using a new acquisition device based on two mini-lenses assembled as …
3D image acquisition system based on shape from focus technique
2013
agent Agrosup Dijon de l'UMREcolDurGEAPSI; This paper describes the design of a 3D image acquisition system dedicated to natural complex scenes composed of randomly distributed objects with spatial discontinuities. In agronomic sciences, the 3D acquisition of natural scene is difficult due to the complex nature of the scenes. Our system is based on the Shape from Focus technique initially used in the microscopic domain. We propose to adapt this technique to the macroscopic domain and we detail the system as well as the image processing used to perform such technique. The Shape from Focus technique is a monocular and passive 3D acquisition method that resolves the occlusion problem affecting…