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Unmanned Aerial System applications in construction
Published in Anil Sawhney, Mike Riley, Javier Irizarry, Construction 4.0, 2020
Masoud Gheisari, Dayana Bastos Costa, Javier Irizarry
In the construction sector, rotary-wing UASs are more frequently employed than fixed-wing models (Zhou and Gheisari, 2018). The unique advantage of a rotary-wing aircraft is that it can take off and land vertically and also hover over any chosen area, something that fixed-wing vehicles cannot do, requiring extensive runways for takeoff and landings, which can be difficult to find on many construction sites. However, when circumstances allow the aircraft to fly at greater altitude and over larger areas (e.g. extensive construction sites, highways), fixed-wing UASs could be a preferable solution.
Assessing Helicopter Pilots
Published in Robert Bor, Carina Eriksen, Todd P. Hubbard, Ray King, Pilot Selection, 2019
Paul Dickens, Christine Farrell
The above quote from a news correspondent during the Vietnam War reflects the layman’s concept of the key differences between fixed- and rotary-wing aircraft – the differences in pilot personality we will investigate later! The two aircraft are radically different. The same aerodynamic theories are valid, but they are applied differently. A fixed-wing aircraft is dynamically stable and theoretically much easier to fly. If it is trimmed correctly and the conditions are relatively calm, a pilot can take his/her hands off the controls for a bit. A helicopter is inherently unstable, and taking your hands off the controls during flight will generally result in disaster. A rotary-wing aircraft has wings that spin to create lift and a tail rotor to compensate for engine torque. A fixed-wing aircraft is an aircraft where the wings are fixed to the airplane and the thrust from the engines provides the forward motion, and airflow over the wings creates lift and over the rudder compensates for torque. This marked difference leads to a very different set of skills required by the helicopter pilot.
UAS Sensing: Theory and Practice
Published in Douglas M. Marshall, R. Kurt Barnhart, Eric Shappee, Michael Most, Introduction to Unmanned Aircraft Systems, 2016
Rotorcraft, or rotor wing aircraft, use spinning wings as their primary source of lift. These take the form of propellers, similar to the ones used to generate motion in the fixed-wing and buoyant aircraft, the chief difference being these are designed to lift the aircraft’s entire weight and control it in flight. Because the spinning blades are used to generate lift, the aircraft is capable of vertical takeoff and landing (VTOL). There are two general types of rotorcraft, single rotor and multi-rotor. The single rotor, what we grew up calling helicopters, use a single main lift rotor to both lift and control the vehicle. The single rotor lift system is marked by complicated mechanical linkages that allow for the adjustment of blade pitch in both the cyclic and collective senses, which allows the vehicle to pitch and roll while varying the overall amount of lift generated. To counteract the single lift rotor’s torque, they also utilize a much smaller tail rotor, the speed of which is coupled with the lift rotor speed and enables the aircraft to yaw on command.
CLEA-256-based text and image encryption algorithm for security in IOD networks
Published in Cogent Engineering, 2023
Snehal Samanth, Prema K V, Mamatha Balachandra
UAVs or Drones have been used in various aspects of technology in the last several decades. Initially, UAVs were used only for military applications, research, and education. But later on, drones have been used for various other applications like telecommunication, agriculture, medicines, food delivery, etc. Many applications and software have been designed to make the drones user-friendly and interface the drones with other devices, to enhance their performance. Many researchers have also worked towards the automation of drones, i.e. drones are programmed to get data, analyze data, take decisions, etc. (Al Habsi et al., 2015). According to the flight type, drones can be classified as Fixed wing drones, Rotor Wing drones, Co-axial drones, Tilt-Rotor drones, and Multi-rotor drones (Kim et al., 2015). A typical drone system consists of the following components: a flight controller, multiple rotors, a remote controller, and a wireless receiver. The flight controller (FC) receives input signals from the remote controller through the wireless receiver, and the FC controls the orientation, speed, altitude, and other parametrs of the drone based on the pilot’s convenience (Son et al., 2015). A network of drone(s) and a GCS is called an Internet of Drones (IoD) network.
Differentiator application in altitude control for an indoor blimp robot
Published in International Journal of Control, 2018
Yue Wang, Gang Zheng, Denis Efimov, Wilfrid Perruquetti
Robotics is a quickly developing area of science and technology nowadays. Frequently, robots are developed for replacing humans in dangerous operating conditions or for optimisation of manufacturing expenses. According to their operating environment, robots can be classified into two types: indoor or outdoor, since depending on that they have different restrictions on dimensions, noise level, actuators and sensors used. Among the flying robots it is worth to mention airships or blimps which are lighter-than-air (LTA) aircrafts, for their long endurance in air, high payload-to-weight ratio, and low noise level features, compare with fixed-wing aircrafts and rotor-wing aircrafts (Li, Nahon, & Sharf, 2011).
Coupled CFD/MBD Method for a Tilt Tri-rotor UAV in Conversion of Flight Modes
Published in International Journal of Computational Fluid Dynamics, 2020
Guilin Wen, Dong Wu, Hanfeng Yin, Daibing Zhang
More and more researches about tilt-rotor aircrafts are carried on by solving Navier–Stokes equations. However, for aerodynamic analyses of this type of aircrafts, people must rise to the challenges of computational problems, such as the aerodynamic interactions during the conversion of flight modes, and large-scale computation in large-space and wide-speed range simulations. The aerodynamic requirements of both helicopter rotor and aeroplane propeller should be met by the tilt rotor of the tilt-rotor aircraft, which make the blade compared to the helicopter blade with bigger torsion angle, bigger disk loading, and larger solidity (Maisel, Giulianetti, and Dugan 2000). With these features, the downwash flow of the blade is different from that of the helicopter blade and the aeroplane propeller. And there is strong aerodynamic interference between the rotor/fuselage/wing (Ye et al. 2016). Researchers have carried out some effective numerical methods to calculate the dynamic characteristics of the tilt-rotor aircraft. The uniform momentum source method for the rotor and embedded grids for the simplified fuselage/wing were adopted by Gupta (2005) to simulate the interference flow field between the rotor/fuselage/wing of a tilt quad-rotor UAV. The uniform momentum source method, also called uniform actuator disk method, was first proposed by Rajagopalan and Lim (1991). With this method, the periodic effect of a rotor on the air is replaced by the momentum source term for generating a time-averaged downwash flow and reducing the calculation amount. But the uniform momentum source method does not take into account the unsteady-flow characteristics of the rotor consisting of several blades. For considering the unsteady features of flow, the non-uniform momentum source method was presented (Tadghighi and Anand 2005; Kim and Park 2012). Although the momentum source methods are efficient, these methods can not accurately capture the flow details near the rotor/wing because of the severe wake distortion and conspicuous flow separation created by tilt-rotor aircrafts’ rotors. Further, the real blade model method was adopted (Norton 2004; Kaul and Ahmad 2011). With this method, Navier–Stokes equations were used to calculate the physical variables of the body-fitted grids, and the interference flow between rotor/fuselage/wing was simulated accurately.