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The purpose of this paper is to examine the cross‐coupled responses of a coupled rotor‐fuselage flight dynamic simulation model, including a finite‐state inflow aerodynamics and a coupled flap‐lag and torsion flexible blade structure.

The methodology is laid out based on model development for an articulated main rotor, using the theories of aeroelastisity, finite element and finite‐state inflow formulation. The finite‐state inflow formulation is based on a 3D unsteady Euler‐based concepts presented in the time domain. The most advantages of the model are the capability of modeling dynamic wake effects, tip losses and skewed wake aerodynamics. This is, in fact, a special type of the inflow model relating inflow states, to circulatory blade loadings through a set of first‐order differential equations. A non‐iterative solution of the differential equations has practically altered the model into a simple and direct formulation appending properly to the rest of the helicopter mathematical model. A non‐linear distribution of the induced velocity over the rotor disc is finally obtained by the use of both Legendre polynomials and higher‐harmonic functions. Ultimately, validations of the theoretical results show that the on‐axis response, direct reaction to the pilot input, has a good accuracy both quantitatively and qualitatively against flight test data, and the off‐axis response, cross‐coupled or indirect reaction to the pilot input are improved by this approach of modeling.

Improvements in dynamic prediction of both trim control settings and dynamic cross‐coupled responses of helicopter to pilot inputs are observed.

Further work is required for investigation of the augmented finite state inflow model, including the wake rotation correction factors to describe helicopter maneuvering flight characteristics.

The results of this work support the future researches on design and development of advanced flight control system, incorporating a high bandwidth with low‐phase delay to control inputs and also high levels of dynamic stability within minimal controls cross coupling.

This paper provides detailed characteristics on the mathematical integration problems associated with the advanced helicopter flight dynamics research.

This paper aims to focus on mathematical model development issues, necessary for a better prediction of dynamic responses of articulated rotor helicopters.

The methodology is laid out based on model development for an articulated main rotor, using the theories of aeroelastisity, finite element and state‐space represented indicial‐based unsteady aerodynamics. The model is represented by a set of nonlinear partial differential equations for the main rotor within a state‐space representation for all other parts of helicopter dynamics. The coupled rotor and fuselage formulation enforces the use of numerical solution techniques for trim and linearization calculations. The mathematical model validation is carried out by comparing model responses against flight test data for a known configuration.

Improvements in dynamic prediction of both on‐axis and cross‐coupled responses of helicopter to pilot inputs are observed.

Further work is required for investigation of the unsteady aerodynamics, a state‐space representation, within various compatible dynamic inflow models to describe the helicopter response characteristics.

The results of this work support ongoing research on the development of highly accurate helicopter flight dynamic mathematical models. These models are used as engineering tools both for designing new aerial products such as modernized agile helicopters and optimization of the old version products at minimum time and expense.

Provides further information on the mathematical model development problems associated with advanced helicopter flight dynamics research.

The purpose of this paper is to describe optical flow‐based navigation of a very light fixed‐wing aircraft in flight between obstacles.

The optical flow information of two cameras mounted on the aircraft is used to detect the obstacle. It is assumed that the image processing has been completed and the optical flow vectors have been obtained beforehand. The optical flow is used to detect the obstacles and make a rapid turn manoeuvre for the aircraft.

It is shown that using the optical flow feedback by itself is unable to give a rapid turn to the aircraft and its rate should be employed into the control law. Six degree‐of‐freedom flight simulation showed that the proposed navigation and control strategy give satisfactory results in different flight environments like corridors with parallel and non‐parallel walls and in the L junctions. Simulations also showed that the aircraft flight velocity has little effect on collision avoidance performance.

This paper provides a theoretical framework to study the different parameters affect the obstacle detection and avoidance of an aircraft.

An analytical equation has been developed to relate the obstacle detection distance to the aircraft manoeuvrability parameters. In addition, an optical flow‐based controller also has been designed to provide rapid turn manoeuvres using the aileron control surface.