Third International Symposium on Magnetic Suspension Technology

In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Third International Symposium on Magnetic Suspension Technology was held at the Holiday Inn Capital Plaza in Tallahassee, Florida on 13-15 Dec. 1995. The symposium included 19 sessions in which a total of 55 papers were presented. The technical sessions covered the areas of bearings, superconductivity, vibration isolation, maglev, controls, space applications, general applications, bearing/actuator design, modeling, precision applications, electromagnetic launch and hypersonic maglev, applications of superconductivity, and sensors

Fourth International Symposium on Magnetic Suspension Technology

In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Fourth International Symposium on Magnetic Suspension Technology was held at The Nagaragawa Convention Center in Gifu, Japan, on October 30 - November 1, 1997. The symposium included 13 sessions in which a total of 35 papers were presented. The technical sessions covered the areas of maglev, controls, high critical temperature (T(sub c)) superconductivity, bearings, magnetic suspension and balance systems (MSBS), levitation, modeling, and applications. A list of attendees is included in the document

Aerodynamic control of a vehicle with flexible longitudinal mode

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1993.Includes bibliographical references (leaves 146-148).by Edward Kenneth Walters II.M.S

Magnetic Suspension and Balance Systems: A Comprehensive, Annotated Bibliography

This bibliography contains 301 entries. Results are reported of recent studies aimed at increasing the research capabilities of magnetic suspension and balance systems; e.g., increasing force and torque capability, increasing angle of attack capability, and increasing overall system reliability. The problem is addressed of scaling from the relatively small size of existing systems to much larger sizes. The purpose of the bibliography is to provide an up-to-date list of publications that might be helpful to persons interested in magnetic suspension and balance systems for use in wind tunnels. The arrangement is generally chronological by date of presentation. However, papers presented at conferences or meetings are placed under dates of presentation. The numbers assigned to many of the citations have been changed from those used in the previous bibliography. This has been done in order to allow outdated citations to be removed and some recently discovered older works to be included in their proper chronological order. Author, source, and subject indexes are included in order to increase the usefulness of this compilation

Leviduction-- a study in electromagnetic levitation

Imperial Users onl

Quadrotor multibody modelling by vehiclesim: adaptive technique for oscillations in a PVA control system

The work presented here covers the detailed modelling and trajectory control for an elastic bladed quadrotor vehicle. The benefits of using VehicleSim modelling software are also discussed. The authors present a full elastic structural and dynamical model as well as two different aerodynamic models. These two aerodynamic models differ from each other on their level of complexity and therefore, accuracy. The control methodology employed to stabilize and guide the vehicle is PVA (ProportionalVelocity-Acceleration), derived and implemented by using Simulink. As it will be shown, it stabilises and provides satisfactory quadrotor trajectory tracking. Since the control methodology feeds back the acceleration of the vehicle, and this acceleration has an oscillating nature, an adaptive process has been designed and introduced into the vehicle’s model in order to avoid the oscillations’ transmission to the control system, showing how it reduces the amplitude of the control actions oscillations. Results of simulations and discussion on them are also provided at the end of this article

An Investigation into Dynamic Stability of Waterborne Aircraft on Take-off and Landing

This research contributes to the knowledge of dynamic stability of waterborne aircraft and ground effect phenomenon. Hereto an analytical and computational study has been performed during which the motion of waterborne aircraft in take-off and landing is predicted. An analytical tool that can be used to predict the nonlinear heaving and pitching motions of seaplanes is presented. First, the heaving and pitching equations of motion are presented in their general Lagrangian form. Then, the equations are simplified to a form of nonlinear equations known as the forced Duffing equations with cubic nonlinearity. The system of motion is assumed to be driven by a sinusoidal head sea wave. The equations are then solved using the Poincare-Lindstedt perturbation method. The analytical solution is verified with CFD simulations performed on Ansys Fluent and AQWA. The solution is used to extend Savitsky’s method to predict porpoising which is a form of dynamic instability found in high-speed boats and seaplanes. The results of the analytical tool are in very good agreement with the results obtained from Fluent and AQWA. However, as the motion is assumed to be 2D in Fluent, heaving amplitude is slightly over predicted. Moreover, the frequency of oscillations of the 2D simulations is found to be unsteady. The unsteadiness in frequency increases with the increase of the length of the hull. Nevertheless, the amplitude of the pitch motion is slightly less than the amplitude predicted analytically. The discrepancy in the results is due to the characteristics of the 2D simulations that assumes that sea water will only pass underneath the hull which will make the buoyancy force greater as less damping is experienced. This is also a consequence of the fact that parameters within the analytical model of heave and pitch are calculated using a strip theory which considers only hydrodynamic effects, while Fluent also incorporate aerodynamic contributions. Similarly, AQWA is a 3D platform that only takes in consideration hydrodynamic effects. Hence, the results of AQWA are slightly less in amplitude than that predicted analytically. In addition, it was found that the frequency of oscillations obtained using AQWA increases with time while in the analytical approach, the frequency of oscillations can only be assumed to be constant for the whole period of motion. The increment in the oscillations indicates that porpoising is taking place. Nevertheless, it was found that heaving terms control the amplitude of motion and pitching terms control frequency of oscillations. The pitching nonlinear term has an effect on the amplitude of motion but not significant. Finally, the analytical method of Savitsky that is used to predict the porpoising stability limit is extended to find the porpoising limit for a wider range of pitch angles. In addition, the porpoising limit is predicted for a planing hull that is moving under the effect of head sea waves. When the seaplane is moving through head sea waves at a fixed pitch angle, porpoising takes place at a lower speed than what Savitsky has predicted

Towards MAV Autonomous Flight: A Modeling and Control Approach

This thesis is about modeling and control of miniature rotary-wing flying vehicles, with a special emphasis on quadrotor and coaxial systems. Mathematical models for simulation and nonlinear control approaches are introduced and subsequently applied to commercial aircrafts: the DraganFlyer and the Hummingbird quadrotors, which have been hardware-modified in order to perform experimental autonomous flying. Furthermore, a first-ever approach for modeling commercial micro coaxial mechanism is presented using a flying-toy called the Micro-mosquito

Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)

The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones