Helicopter SONAR Control: Cable Control for Helicopter Dipping SONAR Operations in Hover using Incremental Nonlinear Dynamic Inversion

Control of a helicopter with a deployed dipping sound navigation and ranging (SONAR) is no trivial task due to the complex dynamics of the suspension cable. The cable can change shape, which influences the effect of water, wind and the motion of the helicopter itself. To control such a system, a control method is needed that can cope with these...

Understanding the use of automation in helicopters

Helicopters possess the unique capability of hovering stationary in the air and landing with relative ease in a variety of terrain, which sets them apart from fixed-wing aircraft. However, due to operations close to terrain and obstacles, piloting a helicopter can be a challenging task that involves risk of incidents and accidents. One avenue to...

Hover and fast flight of minimum-mass mission-capable flying robots

Highly automated Unmanned Aerial Vehicles (UAVs) or "flying robots" are rapidly becoming an important asset to society. The last decade has seen the advent of an impressive number of new UAV types and applications. For many applications, the UAVs need to be safe, highly automated, and versatile. Safety is a prerequisite to allowing their use in...

Human-automation interaction for helicopter flight: Comparing two decision-support systems for navigation tasks

This paper investigates the effects of different automation design philosophies for a helicopter navigation task. A baseline navigation display is compared with two more advanced systems: an advisory display, which provides a discrete trajectory suggestion; and a constraint-based display, which provides information about the set of possible...

Modeling the Effects of Blade Dissimilarity on Rotor Vibrations for CH-47 Chinook Using a Viscous Vortex Particle Method

This work is a part of the Automated Rotor Blade Inspection (ARBI) project. ARBI aims to improve the rotorcraft RTB process with novel rotor blade measurement equipment such as 3D scanning, thermography and shearography. The research aims to quantify the effects of changes in blade properties on rotor vibration levels for CH-47 Chinook. This is...

Feasibility Study of a Load Alleviation Strategy on a Compound Helicopter Using Redundant Controls

The compound helicopter gains interest as operational needs push future rotorcraft capabilities beyond current standards. The compound helicopter is investigated as part of the Future Vertical Lift Program to replace the entire U.S. Army helicopter fleet. The compound helicopter resembles a mix between a fixed-wing aircraft...

Free Water in Helicopter Fuel Tanks: A Computational Prediction Study

Water accumulating in the fuel tanks of any aircraft presents an unacceptable safety hazard. This accumulation, which is due to a combination of physical phenomena, is difficult to assess and therefore not well known. The purpose of this project is the development of a lightweight computational prediction method for water accumulation in...

Locating potential landing zones with the help of digital surface models

The current procedure of the 11 Air Manoeuvre Brigade (11 AMB) is based on a manual non integrated and slow method that uses only outdated and only topographical data. In the procedure are all 5 aspects of a potential landing zone taken into account, the so called 5S: Slope, Shoots, Surface, Size and Security.<br/>This research led to an...

Fuel Cell and Battery Hybrid System Optimization: Towards Increased Range and Endurance

Aircraft manufacturers are increasingly exploring emission-free flight or emission reduction for larger passenger aircraft. The low energy density of state-of-the-art battery technology limits the application to small, electric, fixed wing aircraft up to a flight time of approximately one hour. To overcome these limits, a combination of fuel...

Helicopter Roll-Axis Instabilities induced by Pilot Cyclic Control: A Physical Explanation

The main objective of this paper is to give a basic understanding of the mechanisms through which pilot cyclic inputs in lateral cyclic interacts with high-order rotor dynamics destabilizing the helicopter roll motion. The paper will use a “Newtonian formulation” representing the main forces acting on the airframe body-rotor system as the pilot...

Reliability modelling for rotorcraft component fatigue life prediction with assumed usage

Fatigue life is a random variable. The reliability of a conservative fatigue life prediction for a component in the helicopter dynamic system thus needs to be substantiated. A standard analytical substantiation method uses averaged manoeuvre loads instead of seeing manoeuvre loads as a random variable whose distribution is estimated with limited...