Applications of the unsteady vortex-lattice method in aircraft aeroelasticity and flight dynamics

This paper presents a tracking controller applicable to tethered flying objects, such as kites for power generation or towing purposes. A kinematic framework is introduced, employing definitions and terminology known from aerospace engineering, and is used for both modeling and control design. Derived from measurement data, an empirical steering-law correlation is presented, establishing a highly reliable connection between the steering inputs and the kite’s yaw rate, and thus providing an essential part of the cascaded controller. The target trajectory is projected onto a unit sphere centered at the tether anchor point, and based on geometrical considerations on curved surfaces, a tracking-control law is derived, with the objective to reduce the kite’s spacial displacement smoothly to zero. The cascaded controller is implemented and integrated into the software and hardware framework of a 20 kW technology demonstrator. Because of the lack of a suitable simulation environment, its performance is assessed ...

Applied Tracking Control for Kite Power Systems

This paper describes field experiments with an X8 Unmanned Aerial Vehicle (UAV) operating as a wireless communication relay while loitering over a REMUS 100 Autonomous Underwater Vehicle (AUV) being at the ocean surface. The paper describes the design of the communication relay payload, network configuration, optimal flight conditions and UAV antenna mounting, and experimental results. Experiments were conducted under less than ideal conditions with rain and turbulent winds leading to unfavorable roll and pitch motions of the UAV, and small waves surrounding the AUV. The results with data download from the AUV through the UAV communication relay to a ground station shows that at the tested (typical) flight conditions the distance and attitude between the AUV and UAV are not the bottlenecks in the communication network. The main bottleneck was identified as the capacity of the proprietary wireless system on the REMUS 100 AUV which was not specified as a high capacity data link, and seems to be set up by the AUV system manufacturer to provide a relatively low capacity, but very robust, wireless data link regardless of signal strength and quality.

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Unmanned aerial vehicle as communication relay for autonomous underwater vehicle — Field tests

This paper deals with the design of a robust nonlinear controller for a highly maneuverable missile. Stabilization and tracking are achieved, exploiting a detailed nonlinear model of the six-degree-of-freedom, nonminimum phase, uncertain, and time-varying dynamics of a non-axial-symmetric air-to-air tail-controlled missile. A robust backstepping approach is applied to the multi-input/multi-output model to achieve both bank-to-turn and skid-to-turn maneuvers. Control objectives consist of following the reference signals in angle of attack, sideslip, and bank angle produced by the external guidance system, in order to pursue highly agile maneuvers. Uncertain terms, mostly due to aerodynamic coefficients and dynamic pressure, are suitably limited by bounding functions constructed using experience, a priori knowledge on system behavior, and a bit of conservatism. Robust sigmoidlike control functions are then used to dominate in size the uncertain terms. The whole control system is shown to be practically-robu...

Nonlinear Autopilot Design for an Asymmetric Missile Using Robust Backstepping Control

Maneuverability modeling and trajectory tracking for fish robot

The study of flight dynamics requires a thorough understanding of the theory of the stability and control of aircraft, an appreciation of flight control systems and a grounding in the theory of automatic control. Flight Dynamics Principles is a student focused text and provides easy access to all three topics in an integrated modern systems context. Written for those coming to the subject for the first time, the book provides a secure foundation from which to move on to more advanced topics such as, non-linear flight dynamics, flight simulation, handling qualities and advanced flight control. About the author: After graduating Michael Cook joined Elliott Flight Automation as a Systems Engineer and contributed flight control systems design to several major projects. Later he joined the College of Aeronautics to research and teach flight dynamics, experimental flight mechanics and flight control. Previously leader of the Dynamics, Simulation and Control Research Group he is now retired and continues to provide part time support. In 2003 the Group was recognised as the Preferred Academic Capability Partner for Flight Dynamics by BAE SYSTEMS and in 2007 he received a Chairman's Bronze award for his contribution to a joint UAV research programme. New to this edition: * Additional examples to illustrate the application of computational procedures using tools such as MATLAB , MathCad and Program CC . * Improved compatibility with, and more expansive coverage of the North American notational style. * Expanded coverage of lateral-directional static stability, manoeuvrability, command augmentation and flight in turbulence. * An additional coursework study on flight control design for an unmanned air vehicle (UAV).

Michael V. Cook

Papers

Flight Dynamics Principles: A Linear Systems Approach to Aircraft Stability and Control