نتایج جستجو برای: helicopter services

تعداد نتایج: 304275  

2003
Stefan Hrabar Gaurav S. Sukhatme

We present the design and implementation of an omnidirectional vision system used for sideways-looking sensing on an autonomous helicopter. To demonstrate the capabilities of the system, a visual servoing task was designed which required the helicopter to locate and move towards the centroid of a number of visual targets. Results are presented showing that the task was successfully completed by...

Journal: :IEEE Trans. Aerospace and Electronic Systems 2000
Moustafa Elshafei Sohail Akhtar Mohammed Shahgir Ahmed

An artificial neural network (ANN) based helicopter identification system is proposed. The feature vectors are based on both the tonal and the broadband spectrum of the helicopter signal. ANN pattern classifiers are trained using various parametric spectral representation techniques. Specifically, linear prediction, reflection coefficients, cepstrum, and line spectral frequencies (LSF) are comp...

2004
Lili Ma YangQuan Chen

Electrical companies routinely inspect their overhead lines by helicopter. Current detailed aerial inspection approach uses trained inspectors who fly aboard helicopters to inspect the lines with binoculars and cameras, while recording the data in a logbook. The procedure is performed while the helicopter hovers over and around power lines and structures, creating an element of danger for the p...

2002
Srikanth Saripalli James F. Montgomery Gaurav S. Sukhatme

We present the design and implementation of a realtime, vision-based landing algorithm for an autonomous helicopter. The helicopter is required to navigate from an initial position to a final position in a partially known environment based on GPS and vision, locate a landing target (a helipad of a known shape) and land on it. We use vision for precise target detection and recognition. The helic...

2008
Christian Bermes Kevin Sartori Dario Schafroth Samir Bouabdallah Roland Siegwart

This paper shows roll and pitch feedback control on a coaxial mini helicopter equipped with a center of gravity steering mechanism. The helicopter carries a minimal set of sensors to measure yaw rate, distance to ground and roll and pitch angle. While yaw rate and distance to ground control are already realized on the helicopter, roll and pitch control including the necessary signal filtering a...

1998
T. J. Koo

This paper proposes a hierarchical hybrid architecture of a reactive system that governs the operation of a helicopter based UAV. The mission of the helicopter is to search for, investigate and locate objects in an unknown environment. To perform visual navigation, the helicopter is equipped with a Flight Vehicle Management System(FVMS) and a vision system that scans the ground for objects and ...

2012
R. Bardera Mora

Launch and recovery helicopter wind envelope for a ship type was determined as the first step to the helicopter qualification program. Flight deck velocities data were obtained by means of a two components laser Doppler anemometer testing a 1/50 model in the wind tunnel stream. Full-scale flight deck measurements were obtained on board the ship using a sonic anemometer. Wind tunnel and full-sca...

Journal: :International maritime health 2014
Steve Williams Eilif Dahl

Physicians and nurses from shore based practice who move to work on cruise ships often have concerns about the management of critically ill patients and questions about the resources available to transfer by helicopter to a tertiary care facility. This article seeks to outline some of the clinical, operational and logistical issues associated with using a helicopter to transfer a patient from a...

Journal: :The Journal of trauma 2006
Bryan E Bledsoe A Keith Wesley Marc Eckstein Thomas M Dunn Michael F O'Keefe

BACKGROUND Helicopters have become a major part of the modern trauma care system and are frequently used to transport patients from the scene of their injury to a trauma center. While early studies reported decreased mortality for trauma patients transported by helicopters when compared with those transported by ground ambulances, more recent research has questioned the benefit of helicopter tr...

2012
SAMIR ZEGHLACHE DJAMEL SAIGAA

In this paper we present a new design method for the fight control of an autonomous quadrotor helicopter based on fuzzy sliding mode control using backstepping approach. Due to the underactuated property of the quadrotor helicopter, the controller can move three positions (x,y,z) of the helicopter and the yaw angle to their desired values and stabilize the pitch and roll angles. A first-order n...

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