scholarly journals Helicopter Flight Physics

2018 ◽  
Author(s):  
Constantin Rotaru ◽  
Michael Todorov
Keyword(s):  
Helicopter Flight

scholarly journals Improving a real-time helicopter simulator model with linear input filters

2021 ◽  
Author(s):  
Pavle Šćepanović ◽  
Frederik A. Döring
Keyword(s):  
Feedback Control ◽  
Time Domain ◽  
Flight Test ◽  
Flight Mechanics ◽  
Mean Square ◽  
Qualification Test ◽  
Model Inversion ◽  
Helicopter Flight ◽  
The Time Domain ◽  
Mean Square Errors

AbstractFor a broad range of applications, flight mechanics simulator models have to accurately predict the aircraft dynamics. However, the development and improvement of such models is a difficult and time consuming process. This is especially true for helicopters. In this paper, two rapidly applicable and implementable methods to derive linear input filters that improve the simulator model are presented. The first method is based on model inversion, the second on feedback control. Both methods are evaluated in the time domain, compared to recorded helicopter flight test data, and assessed based on root mean square errors and the Qualification Test Guide bounds. The best results were achieved when using the first method.

Machine vision-based sensing for helicopter flight control

Robotica ◽  
2000 ◽  
Vol 18 (3) ◽  
pp. 299-303 ◽  
Author(s):  
Carl-Henrik Oertel
Keyword(s):  
Machine Vision ◽  
Measurement System ◽  
Flight Control ◽  
A Priori ◽  
Image Data ◽  
Two Dimensional ◽  
Position Measurement ◽  
Additional Information ◽  
Helicopter Flight ◽  
Template Tracking

Machine vision-based sensing enables automatic hover stabilization of helicopters. The evaluation of image data, which is produced by a camera looking straight to the ground, results in a drift free autonomous on-board position measurement system. No additional information about the appearance of the scenery seen by the camera (e.g. landmarks) is needed. The technique being applied is a combination of the 4D-approach with two dimensional template tracking of a priori unknown features.

Helicopter flight control compensator design

2017 ◽  
Author(s):  
Malika Yaici ◽  
Kamel Hariche ◽  
Tim Clarke
Keyword(s):  
Flight Control ◽  
Helicopter Flight ◽  
Compensator Design

Helicopter Rotor Blade Flexibility Simulation for Aeroelasticity and Flight Dynamics Applications

2014 ◽  
Vol 59 (4) ◽  
pp. 1-18 ◽  
Author(s):  
Ioannis Goulos ◽  
Vassilios Pachidis ◽  
Pericles Pilidis
Keyword(s):  
Real Time ◽  
Rotor Blade ◽  
Flight Dynamics ◽  
Integrated Approach ◽  
Flight Simulation ◽  
Response Characteristics ◽  
Helicopter Flight ◽  
Finite State ◽  
The Time Domain ◽  
Blade Loads

This paper presents a mathematical model for the simulation of rotor blade flexibility in real-time helicopter flight dynamics applications that also employs sufficient modeling fidelity for prediction of structural blade loads. A matrix/vector-based formulation is developed for the treatment of elastic blade kinematics in the time domain. A novel, second-order-accurate, finite-difference scheme is employed for the approximation of the blade motion derivatives. The proposed method is coupled with a finite-state induced-flow model, a dynamic wake distortion model, and an unsteady blade element aerodynamics model. The integrated approach is deployed to investigate trim controls, stability and control derivatives, nonlinear control response characteristics, and structural blade loads for a hingeless rotor helicopter. It is shown that the developed methodology exhibits modeling accuracy comparable to that of non-real-time comprehensive rotorcraft codes. The proposed method is suitable for real-time flight simulation, with sufficient fidelity for simultaneous prediction of oscillatory blade loads.

TASKILLAN: A Simulation to Predict the Validity of Multiple Resource Models of Aviation Workload

1988 ◽  
Vol 32 (2) ◽  
pp. 168-172 ◽  
Author(s):  
Christopher D. Wickens ◽  
Kelly Harwood ◽  
Leon Segal ◽  
Inge Tkalcevic ◽  
Bill Sherman
Keyword(s):  
Task Performance ◽  
Model Validation ◽  
Predictive Models ◽  
Spatial Awareness ◽  
Level Flight ◽  
Helicopter Flight ◽  
Processing Resources ◽  
Multiple Resource ◽  
Multiple Task ◽  
Over Time

The objective of this research was to establish the validity of predictive models of workload in the context of a controlled simulation of a helicopter flight mission. The models that were evaluated contain increasing levels of sophistication regarding their assumptions about the competition for processing resources underlying multiple task performance. Ten subjects performed the simulation which involved various combinations of a low level flight task with three cognitive side tasks, pertaining to navigation, spatial awareness and computation. Side task information was delivered auditorily or visually. Results indicated that subjective workload is best predicted by relatively simple models that simply integrate the total demands of tasks over time (r = 0.65). In contrast, performance is not well predicted by these models (r < .10), but is best predicted by models that assume differential competition between processing resources (r = 0.47). The relevance of these data to predictive models and to the use of subjective measures for model validation is discussed.

Helicopter flight characteristics in icing conditions

2012 ◽  
Vol 116 (1183) ◽  
pp. 963-979 ◽  
Author(s):  
Yihua Cao ◽  
Guozhi Li ◽  
R. A. Hess
Keyword(s):  
State Space Model ◽  
Liquid Water Content ◽  
Atmospheric Temperature ◽  
Ice Accretion ◽  
Handling Qualities ◽  
Helicopter Flight ◽  
Different Types ◽  
Ice Shedding ◽  
Temperature Liquid ◽  
Further Development

Abstract A method to predict the effects of rotor icing on the flight characteristics of a UH-60A helicopter is presented. By considering both natural ice shedding and different types of ice accretion due to local temperature variations on the blade surface, an improved rotor icing model was developed. Next, the effects of icing on rotor force, torque and flapping were incorporated in a nonlinear helicopter dynamic model. Based upon icing design envelopes in cumuliform clouds, trim and stability characteristics were studied. Further development of the helicopter state-space model allowed control and handling qualities characteristics to be investigated with variation of the three icing-related cloud variables (atmospheric temperature, liquid water content, and median volumetric diameter). Results indicated that this method of evaluating rotorcraft icing is both feasible and useful.

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