Krzysztof Sibilski

Dynamics of Micro-Air-Vehicle with Flapping Wings

Small (approximately 6 inch long, or hand-held) reconnaissance micro air vehicles (MAVs) will fly inside buildings, and require hover for observation, and agility at low speeds to move in confined spaces. For this flight envelope insect-like flapping wings seem to be an optimal mode of flying. Investigation of the aerodynamics of flapping wing MAVs is very challenging. The problem involves complex unsteady, viscous flow (mainly laminar), with the moving wing generating vortices and interacting with them. At this early stage of research only a preliminary insight into the nature of the little known aerodynamics of MAVs has been obtained. This paper describes computational models for simulation of the controlled motion of a microelectromechanical flying insect – entomopter. The design of software simulation for entomopter flight (SSEF) is presented. In particular, we will estimate the flight control algorithms and performance for a Micromechanical Flying Insect (MFI), a 80–100 mm (wingtip-to-wingtip) device capable of sustained autonomous flight. The SSEF is an end-to-end tool composed of several modular blocks which model the wing aerodynamics and dynamics, the body dynamics, and in the future, the environment perception, control algorithms, the actuators dynamics, and the visual and inertial sensors. We present the current state of the art of its implementation, and preliminary results.

MODELING AND SIMULAT ION OF THE NONLINEAR DYNAMIC BEHAVIOR OF A FLAPPING WINGS MICRO - AERIAL - VEHI CLE

This paper describes nonli near computational model for the simulation of co ntrolled motion of flapping wings Micro Air Vehicle. The following assumptions are made: the motion of wings are d ecomposed into flapping, lagging, and feathering rot ations; each wing is rigid and rotates ab out the co mmon axis; aerod ynamic forces coming from airfoils have periodical character; the wing vortices are ge nerated at the trai ling edge only; the shape of the wake is determined from calc ulations via a time -stepping procedure. Because of highly nonlin ear dynamics of flapping wings MAVs over the flight env elope, the state space formulation with the linearized equ ations of motion is not sufficient to describe the co upled dynamics of those vehicles. Therefore, a model with the complete nonlinear different ial equations of m otion and nonlinear aerodyna mics is derived.

The Comparative Evaluation of Power Requirements for Fixed, Rotary, and Flapping Wings Micro Air Vehicles

In this paper we describe power requirements for micro air vehicles. We have researched three flight modes: fixed wing, rotary wing and flapping wing. We have calculated energy and power requirements for the three flight modes. As we can excepted, when there is no hover requirement, fixed wing flight is always most energy efficient for the micro air vehicle. However, if there is a hover requirement, the suitability of flapping or rotary wing flight is dependent on the mission profile and ambient windspeed.

Aircraft Climbing Flight Dynamics With Simulated Ice Accretion

In the paper results of icing of aircraft in climbing flight were analyzed. It was assumed that in the initial phase icing causes only deterioration of aerodynamic characteristics of aircraft and does not cause a significant change in mass distribution of a plane. Exemplary calculations were made for a jet training aircraft. Different variants of degradation of an aeroplane lift were analyzed (depending on time of icing of a plane’s lifting surface and this time’s influence on lowering a lift’s coefficient).

Comparative Evaluation of Power Requirements for Fixed, Rotary, and Flapping Wings Micro Air Vehicles

In this paper we describe power requirements for micro air vehicles. We have researched three flight modes: fixed wing, rotary wing and flapping wing. We have calculated energy and power requirements for the three flight modes. As we can excepted, when there is no hover requirement, fixed wing flight is always most energy efficient for the micro air vehicle. However, if there is a hover requirement, the suitability of flapping or rotary wing flight is dependent on the mission profile and ambient windspeed.

Influence of Cruise Flight Speed of Entomompter on Aerodynamics Loads

Przedstawiony artykul ściśle nawiązuje do prac nad stworzeniem obiektu latającego, ktory generuje sile nośną tak jak latające owady, czyli entomoptera. Przedstawiona praca dotyczy badan doświadczalnych prowadzonych na mechanizmie trzepoczącym pracującym w tunelu wodnym. Obiekt wyposazony jest w dwa skrzydla. Kazde z nich moze wykonywac dowolny ruch kulisty (obrot wokol punktu). Celem pracy bylo wyznaczenie maksymalnych predkości lotu i uzyskiwanych wartości sil nośnych obiektu dla roznych sposobow ruchu skrzydel. Eksperyment polegal na pomiarze sil hydrodynamicznych generowanych przez obiekt za pomocą wagi tensometrycznej. Ruch skrzydel odbywal sie w jednej plaszczyźnie. Parametrami doświadczenia byly predkośc postepowa oraz kąt pochylenia plaszczyzny trzepotania. Uzyskane wyniki pozwalają na przewidzenie maksymalnej predkości lotu rzeczywistego obiektu dla zadanego udźwigu, wskazują ewentualne sposoby poprawy osiągow. Dają rowniez istotne informacje z punktu widzenia mechaniki lotu, a konkretnie stateczności podluznej ukladu trzepoczącego. Artykul oprocz analizy wynikow eksperymentu zawiera takze opis metodologii pomiarow

Modeling and Simulation of Entomopter Flight Dynamics

This paper is f ocused on develop ing o f the software me ant for simulation of entomopter , obtaining several modules is necessary, which are meant to describe: wing aerodynamics, fuselage motion and control algorithms. Analysis of problems concerning entomopte r’s flight dynamics will be commenced with taking a c loser look at the structure of the oldest and most primitive and simple flying creatures , the insects.

The Continuation Design Framework for Nonlinear Aircraft Control

*† This paper describes the implementation of continuation methods and bifurcation analysis in the “global” identification of control law parameters. In the examples presented, it integrates features of closed loop eigenstructure methods within the nonlinear stateparameter environment. The basis of the continuation design framework (CDF) is outlined and then demonstrated using a highly nonlinear aircraft model. The optimization-based method is used to exercise “bifurcation tailoring” by showing how a mild oscillation can be introduced by the controller as a pilot cue to departure onset. The eigenstructure example also contains bifurcation tailoring,

Biomimic Sensors Guided Flight Stability and Control for Flapping Wings Autonomous Micro Air Vehicles (Entomopter)

MAV flight stability and control presents some difficult challenges. The low moments of inertia of MAVs make them vulnerable to rapid angular accelerations, a problem further complicated by the fact that aerodynamic damping of angular rates decreases with a reduction in wingspan. Another potential source of instability for MAVs is the relative magnitudes of wind gusts, which are much higher at the MAV scale than for larger aircraft. In fact, wind gusts can typically be equal to or greater than the forward airspeed of the MAV itself. Thus, an average wind gust can immediately affect a dramatic change in the vehicle’s flight path. Other problem occurs with influence of flapping wings on MAV’s body motion. The birds and flying insects, the biological counterpart of mechanical MAVs, can offer some important insights into how one may best be able to overcome these problems. Biological systems, while forceful evidence of the importance of vision in flight, do not, however, in and of themselves warrant a computer-vision based approach to MAV autonomy. Fundamentally, flight stability and control requires measurement of the MAV’s angular orientation. While for larger aircraft this is typically estimated through the integration of the aircraft’s angular rates or accelerations, a vision-based system can directly measure the MAV’s orientation. Most of the fly’s neural processing is devoted to vision, and its compound eyes are the key to flight control. Also notable are three light sensitive sensors arranged in a triangle on the top of the head, called ocelli. Research on insect flight revealed that in order to maintain stable flight, insects use structures, called halteres, to detect body rotations via gyroscopic forces. Therefore, we have developed a control system based on mathematical models of ocelli and halteres. We have developed algorithms based on vision and gyroscopic forces detection, and developed simulation tool provides a basis for an advanced description of an entomopter stabilization and dynamic behaviour.

An Inverse Simulation Study on Wing Adapter Kit Dynamics and Control in Prescribed Trajectory Flight

*† This paper presents a uniform approach to the modeling and simulation of smart Winged Adapter Kit (WAK) trajectory flight. WAK is a device that includes a pair of controllable wings which, after bolting onto the standard, general purpose bomb, transforms the weapon from a ballistic chunk of iron into a targetable stand-off glide bomb, thus creating a sophisticated Precision Guided Munitions (PGM) gliding bomb. The WAK motion is specified by a trajectory in space, a condition on a winged bomb attitude with respect to the trajectory, and a desired flight velocity variation. For a WAK controlled by aileron, elevator and rudder deflections changes, a tangent realization of trajectory constraints arises, which yields two additional constraints on the airframe attitude with respect to the trajectory. By combining the program constraint conditions and bomb dynamic equations, the governing equations of programmed motion are developed in the form of differential-algebraic equations. A method for solving the equations is proposed. The solution consists of time variations of the aircraft state variables and the demanded control that ensures the programmed motion realization.