Search results for " meccanica"

Engineering requirements for avionics of unmanned aerial system

Within the framework of the European Project WInSiC4AP, the Unmanned Aerial Vehicle (UAV) use case plays an important role in defining some of the specific constraints that on-board electronics systems must obey. Then it’s relevant to have clear view of the UAVs classification and their main characteristics especially with the focus of an Electrical UAV. Main component of the power supply are batteries, whose requirements must fulfil the tight design constraint such as lightweight, safety, pressure and temperature tolerance, cost effectiveness and cycle life. A quick look to available chemistry technology as well as market overview has been described. Regarding the power sub-system, the key…

Flight Control Research Laboratory Unmanned Aerial System flying in turbulent air: an algorithm for parameter identification from flight data

2013

This work addresses the identification of the dynamics of the research aircraft FCRL (Flight Control Research Laboratory) used for the Italian National Research Project PRIN2008 accounting for atmospheric turbulence. The subject vehicle is an unpressurized 2 seats, 427 kg maximum take of weight aircraft. It features a non retractable, tailwheel, landing gear and a powerplant made up of reciprocating engine capable of developing 60 HP, with a 60 inches diameter, two bladed, fixed pitch., tractor propeller. The aircraft stall speed is 41.6 kts, therefore it is capable of speeds up to about 115 kts (Sea level) and it will be cleared for altitudes up to 10.000 ft. The studied aircraft is equipp…

AN EKF BASED PROCEDURE FOR AUTOMATIC PATH FOLLOWING IN TURBULENT AIR

2017

Aim of the present paper is to propose a procedure to afford an accurate automatic path following in turbulent air. The technique is based on the simultaneous employment of two different EKF. The first estimates disturbances, the second one estimates deflection that are necessary to reject the estimated disturbances. The first EKF uses measurements gathered in turbulent air. The second EKF obtains command laws able to follow the desired flight path rejecting disturbances. To purchase the objective, aerodynamic coefficients have been modified by adding entirely new derivatives or synthetic increments to basic ones. The modified aircraft parameters are determined by augmenting the aircraft’s …

A Non Conventional UAV In Ground Effect: Synthesis of a Robust Flight Control System,

2008

ABSTRACT This paper discusses the synthesis of an Extended Kalman Filter (EKF) to perform both wind velocities and state estimation for a non conventional UAV flying in ground effect. Since, in IGE flight, motions into the symmetry plane are of primary concern, the study focuses on the longitudinal aircraft dynamics. The proposed estimator requires measurement of few flight variables, easily obtainable by means of conventional sensors; besides, it does not use Inertial Measurement Unit (IMU). To simulate a low cost sensing equipment, the model outputs are corrupted by white noise of relatively high standard deviation. Furthermore, to cope with the low rate of the GPS with respect to the oth…

Trajectory tracking for a Non-Conventional UAV

2008

The aim of the present paper is the design of a flight control system for a Tandem – Canard UAV, useful in the whole flight envelope, both Out of Ground Effect (OGE) and In Ground Effect (IGE) conditions. Because of the particular arrangement of the studied aircraft, a general mathematical model has been built in order to obtain non-linear analytical equations for longitudinal aerodynamic coefficients both in OGE and in IGE flight. So the dynamic behaviour of the UAV may be studied during every flight phases i.e. in the whole range of altitude. To consider the strong variation of aerodynamic parameters due to the ground effect presence, a robust control technique (LQG/LTR) has been used to …

Il mercato degli UAS: campi di applicazione

2012

L'utilizzo di Unmanned Aerial Systems (UAS) ha avuto un incremento significativo negli ultimi anni. Il loro impiego, prima riservato ai soli fini militari, si è sempre più rivolto a campi prettamente civili quali, per esempio la sorveglianza, il controllo ambientale ed il rilievo aereo. Nel presente lavoro verrà esaminata dapprima l'evoluzione del campo degli UAS nel mondo, verranno esaminati e descritti i primi sviluppi ed utilizzi fino ai più recenti in modo da dare un panorama completo delle tecnologie in essere, focalizzando, in una seconda parte, l'attenzione su costruttori e sviluppatori sia europei che extraeuropei. Saranno inoltre approfonditi gli usi civili degli UAS che, negli ult…

A NON CONVENTIONAL UAV IN GROUND EFFECT: ESTIMATION OF STATE AND TURBULENCE VIA EXTENDED KALMAN FILTER

2009

ABSTRACT This paper discusses the synthesis of an Extended Kalman Filter (EKF) to perform both wind velocities and state estimation for a non conventional UAV flying in ground effect. Since, in IGE flight, motions into the symmetry plane are of primary concern, the study focuses on the longitudinal aircraft dynamics. The proposed estimator requires measurement of few flight variables, easily obtainable by means of conventional sensors; besides, it does not use Inertial Measurement Unit (IMU). To simulate a low cost sensing equipment, the model outputs are corrupted by white noise of relatively high standard deviation. Furthermore, to cope with the low rate of the GPS with respect to the oth…

EXTENDED VALIDATION OF DYNAMIC IRREVERSIBLE THERMOPORATION: A NOVEL THERMAL PROCESS FOR MICROBIAL INACTIVATION

2017

A novel thermal treatment for microorganism inactivation, characterized by a very rapid temperature increase (up to 30C/s) and a low final temperature (up to 65C) maintained for a relatively short holding time, has been recently presented and tested by the authors, showing microbial load reduction greater than 5 log units against several common bacteria and yeasts. With the aim of extending the possible use of the new thermal treatment to a wider microorganisms class, in this work the dynamic irreversible thermoporation (DIT) treatment was further tested on a well-known thermoresistant strain, the Enterococcus hirae: The results of these new experimental tests confirmed the reliability of t…

PROGETTAZIONE E VERIFICA SPERIMENTALE DI UNA MICROTURBINA IDRAULICA PER L’INDUSTRIA ALIMENTARE

2014

In questo articolo sono descritte le attività di ricerca e sviluppo di una micro-turbina idraulica inserita all’interno di un macchinario che opera un nuovo processo di abbattimento della carica batterica applicabile nell’industria dell’imbottigliamento delle bevande. Peculiarità della turbina progettata è la geometria della palettatura della girante, dritta ed a sviluppo puramente assiale, che ne rende estremamente economica la realizzazione. Lo scambio di energia avviene grazie al moto vorticoso impresso al fluido (swirl) mediante opportuno posizionamento dei condotti di adduzione. Lo studio della turbina è stato condotto mediante classico approccio unidimensionale, mentre il dimensioname…

Modello dinamico di iniettore di gas per motore ad accensione comandata

2010

Nel presente lavoro si studia la complessa dinamica dell’otturatore di un iniettore di gas a solenoide per motori ad accensione comandata; come è noto, esso è sottoposto a spinte di diversa natura ed il suo moto ha un influenza determinante nei confronti della massa di combustibile erogata, la quale viene di norma modulata intervenendo sulla durata dell’intervallo di eccitazione del solenoide, chiamato “tempo di iniezione”. Ad otturatore completamente aperto, la massa di gas che attraversa la sezione di uscita dell’iniettore dipende esclusivamente dalle condizioni del fluido a monte dell’iniettore e dalla durata del tempo di iniezione: ciò rende lineare la caratteristica di funzionamento de…