Search results for "ADC"
showing 10 items of 179 documents
ROS/Gazebo-Based Simulation of Quadcopter Aircrafts
2018
The main purpose of this work is to present a tutorial description on how to design and develop an observer, which is capable of estimating the position and the orientation of a drone commanded by a controller, whose shape and structure are unknown. Starting from Newton's and Euler's laws, a mathematical model describing the dynamics of a quadcopter has first been obtained. By linearizing this model it is possible to implement a Luenberger observer and validate it with simulations in a Linux environment, thanks to the use of the Ardupilot controller and the Gazebo simulator. Finally, starting from the results obtained from the simulation, it is possible to evaluate the error made in the est…
Erle-copter Simulation using ROS and Gazebo
2020
The recent decrease in the price as well as size of semi-conductor logic and due to significant advancements in technologies such as microcontrollers, motors and sensors, the application of quadcopters in several fields has been achieved. However, testing of quadcopter prototypes still has a risk of damage due to faults and unexpected behavior. Hence, a method of testing of quadcopters in simulation mimicking the actual conditions of the real environment in an actual hardware test has been proposed. For this purpose, Gazebo simulator integrated with ROS has been chosen for the simulation of the path of the quadcopter. Moreover, the software Matlab/Simulink has been interfaced with Gazebo in…
Wind gust estimation for precise quasi-hovering control of quadrotor aircraft
2021
Abstract This paper focuses on the control of quadrotor vehicles without wind sensors that are required to accurately track low-speed trajectories in the presence of moderate yet unknown wind gusts. By modeling the wind disturbance as exogenous inputs, and assuming that compensation of its effects can be achieved through quasi-static vehicle motions, this paper proposes an innovative estimation and control scheme comprising a linear dynamic filter for the estimation of such unknown inputs and requiring only position and attitude information. The filter is built upon results from Unknown Input Observer theory and allows estimation of wind and vehicle state without measurement of the wind its…
Demo: Co-simulation of UAVs with INTO-CPS and PVSio-web
2018
This demo shows our ongoing work on the co-simulation of co-operative Unmanned Aerial Vehicles (UAVs). The work is based on the INTO-CPS co-simulation engine, which adopts the widely accepted Functional Mockup Interface (FMI) standard for co-simulation, and the PVSioweb prototyping tool, that extends a system simulator based on the PVS logic language with a web-based graphical interface. Simple scenarios of Quadcopters with assigned different tasks, such as rendez-vous and space coverage, are shown. We assumed a linearized dynamic model for Quadcopters formalized in OpenModelica, and a linearized set of equations for the flight control module written in C language. The co-ordination algorit…
Objective features in quantum states
2023
One of the key features of quantum mechanics is that any superposition of quantum states is in itself a legitimate quantum state. This has far reaching consequences, and is behind the stark difference in behaviour between quantum and classical systems. In particular, quantum systems are not -unlike classical ones- intrinsically objective, that is, different observers are not always able to agree on the properties of the system. Understanding the conditions for objectivity in quantum states is therefore key to address the wider issue of the quantum-to-classical transition. Here, we discuss several aspects of quantum objectivity, and in particular subtleties that arise to the definitions of o…
Before and after Science. Radcliffe-Brown e la questione dei rapporti tra metodi di ricerca sul campo, etnografia e teoria
2020
Nella prima parte del capitolo, mi occupo del periodo iniziale della carriera di Radcliffe-Brown che precede la pubblicazione, nel 1922, del suo celebre scritto, di carattere programmatico, su I metodi dell’etnologia e dell’antropologia sociale. Questo periodo di formazione è segnato dal rapporto con Haddon e Rivers, dalle due esperienze di ricerca sul campo nelle isole Andamane e tra gli aborigeni australiani, e dalla riflessione critica sul modello di scienza sociale proposto da Durkheim, riguardante in particolare le teorie formulate da quest’ultimo a proposito dei tipi di morfologia sociale e del ruolo di integrazione sociale svolto dalle credenze e dai rituali religiosi nelle “società …
Low energy electrons and swift ion track structure in PADC
2015
The current work aims at providing an accurate description of the ion track-structure in poly-allyl dyglycol carbonate (PADC) by using an up-to-date Monte-Carlo code-called TILDA-V (a French acronym for Transport d'Ions Lourds Dans l'Aqua & Vivo). In this simulation the ion track-structure in PADC is mainly described in terms of ejected electrons with a particular attention done to the Low Energy Electrons (LEEs). After a brief reminder of the most important channels through which LEEs are prone to break a chemical bond, we will report on the simulated energetic distributions of LEEs along an ion track in PADC for particular incident energies located on both sides of the Bragg-peak position…
A Fast Anchor Person Searching Scheme in News Sequences
2001
In this paper we address the problem of seeking anchor person shots in news sequences. This can be useful since usually this kind of scenes contain important and reusable information such as interviews. The proposed technique is based on our a priori knowledge of the editing techniques used in news sequences.
LINKAGE DISEQUILIBRIUM AND GENETIC DIVERSITY IN TWO SICILIAN CATTLE BREEDS ASSESSED BY BOVINE SNP CHIP
2013
The Modicana (MOD) and Cinisara (CIN) are two Sicilian cattle breeds farmed in extensive systems and their economic importance lies on the traditional making of two typical ‘pasta filata’ cheeses. The aim of this study was to explore the genetic structure and the extent of Linkage Disequilibrium (LD) of MOD and CIN cattle breeds. A total of 144 animals were genotyped, using the Bovine SNP50K v2 BeadChip. The squared correlation coefficient between two loci (r2) was used as a measure of LD. Principal components analysis (PCA), molecular inbreeding (F) and Bayesian clustering algorithm (Pritchard et al., 2000) were used to explore the relationship between individuals and populations. The r2 r…
Linkage disequilibrium and genetic diversity estimation in three Sicilian autochthonous dairy sheep breeds
2014
Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. In the present study, we used the OvineSNP50K BeadChip to characterize LD, identify haplotype blocks and to analyze genetic diversity in the Valle del Belice (VDB), Comisana (COM) and Pinzirita (PIN) dairy sheep breeds. LD between adjacent SNPs and for all pairwise combinations of SNPs on each chromosome was measured using r2. Haplotype blocks were estimated using D’ based method. Genetic diversity and Principal Component Analysis (PCA) were calculated using PLINK. Small differences in average LD value for adjace…