Unmanned Flight - IEEE Xplore

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Feb 1, 2014 - Leishman, John Macdonald, Randal W. Beard, and Timothy W. McLain consider state estimation for quadrotors, which are small and highly ...
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Unmanned Flight

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any engineers played with aerial vehicles as a child. In the early 1980s, I got a gasolinepowered toy airplane that had strings from the aircraft to the user’s hands to control the airplane’s height as it flew circles around the user. Small aircraft have become significantly more sophisticated since then, and many are no longer toys in terms of sophistication, functionality, and performance. In particular, remote control Digital Object Identifier 10.1109/MCS.2013.2287354 Date of publication: 17 January 2014

is now common in retail offerings. Many control engineering groups in the last ten years have been designing autonomous flight control algorithms, which need no user intervention to map geography, perform land- or seabased search-and-rescue operations, search facilities for chemical leaks, or patrol for suspicious activities. Systems and control algorithms are being developed for a wide variety of small aerial vehicles, including fixedwing aircraft, helicopters, quadrotors, ducted fans, and ultra-lightweight robotic birds. IEEE  Control  Systems

Magazine has closely followed developments in this field since the mid 1990s, with the most recent suite of articles published in the special issue on unmanned aerial vehicles in October 2012 [1]. This month’s issue considers both quadrotors and fixed-wing unmanned aerial vehicles. In the article “Quadrotors and Accelerometers: State Estimation with an Improved Dynamic Model,” Robert C. Leishman, John Macdonald, Randal W. Beard, and Timothy W. McLain consider state estimation for quadrotors, which are small and highly maneuverable

Contributors

Robert Leishman explaining a quadrotor control experiment at the MAGICC Laboratory at Brigham Young University.

Tim McLain vacationing near Monterey, California.

John Macdonald enjoying family time in southern Utah.

Randy Beard enjoying time outdoors.

P.B. Sujit at Plitvice Lakes in Croatia.

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aerial vehicles that, with the proper control algorithms, can autonomously avoid obstacles while flying in confined unknown environments. The article describes an approach for using accelerometer measurements in quadrotor flight to improve state estimation. Experimental flight tests confirm improved accuracy in realtime estimates of vehicle attitude and velocity. In “Unmanned Aerial Vehicle Path-Following: A Survey and Analysis of Algorithms for Fixed-Wing

Srikanth Saripalli.

João B. Sousa in a meeting.

Jeffrey Laut canoeing in the Gowanus Canal.

Unmanned Aerial Vehicles,” P.B. Sujit, Srikanth Saripalli, and João Borges Sousa provide an overview of algorithms for following predefined paths for fixedwing unmanned aerial vehicles. Several pathfollowing algorithms are analyzed and compared, i nc lud i ng a lgor it h m s widely used in commercial autopilots. The algorithms are compared in terms of the sensitivity of the closed-loop performance to variations in control tuning parameters and wind conditions.

Sarah Nelson Wright preparing a boat for the Newtown Creek Armada.

Oded Nov in his office.

Maurizio Porfiri enjoying the fresh air in Brooklyn, New York.

8  IEEE CONTROL SYSTEMS MAGAZINE  »  February 2014

In the “President’s Message,” Jay Farrell describes the benefits of engaging in IEEE Control Systems Society (CSS) professional activities and encourages members to volunteer and provide input. “CSS News” provides an update on IEEE Transactions on Control of Network Systems; encourages nominations for CSS awards, proposals to the CSS Outreach Fund, and volunteers to participate in CSS activities; and announces the recipient of the 2014 Hendrik W. Bode Lecture Prize, the recently elected members of the CSS Board of Governors, and the members of the 2014 CSS Nominating Committee.

Steven Kahne.

Eric Bullinger looking into the distance.

Monica Schliemann in front of a white board.

“Member Activities” provides information on the IEEE CSS Control System Society Outreach Fund, which provides financial resources for projects that benefit CSS and the control community. In “Technical Activities,” Qing-Shan “Samuel” Jia describes recent activities of the CSS Technical Committee on DiscreteEvent Systems. In “Publication Activities,” Francesco Bullo highlights some CSS publication activities over the past year. “People in Control” has interviews with IEEE Fellows João Hespanha, Jeff Shamma, and Aniruddha Datta. “Focus on Education” by Jeffrey Laut, Sarah Nelson Wright, Oded Nov, and Maurizio Porfiri describes the use of remote-control boats outfitted with sensory and telemetry capabilities for educating the public. This issue’s “Historical Perspectives” column is the fourth in a series that commemorates the life and work of Norbert Wiener. This installment is a lecture by John F. Coales, edited

This issue’s “Historical Perspectives” column is the fourth in a series that commemorates the life and work of Norbert Wiener.

by Steven Kahne, on a formerly secret report by Wiener on the application of generalized Fourier analysis to aircraft detection and gunnery. In “Book Reviews,” Monica Schliemann and Eric Bullinger review the book A New Look at Disease: Parkinson’s as Seen Through the Eyes of an Engineer by Peter Wellstead. In “Conference Reports,” Yanlong Zhao reports on the 32nd Chinese Control Conference that was held on July 26–28, 2013 in Xi’an, China, and M. Vidyasagar reports on the 2013 IEEE Multiconference on Systems and Control that was held on August 28–30 in Hyderabad, India. Among the regular columns, “25 Years Ago” revisits an article by

Russell L. Anderson on a robot that played ping pong. “Conference Calendar” lists upcoming conferences sponsored or cosponsored by the CSS over the next three years. “Book Announcements” provides summaries of recently published books in the control field. “On the Lighter Side” considers model predictive control at work, and “Random Inputs” considers random processes.

Reference [1] Special Issue on Unmanned Aerial Vehicles, IEEE Control Syst. Mag., vol. 32, no. 4, pp. 32–109, Oct. 2012.

Richard D. Braatz

The Healing Power of Feedback …

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his is extremely fortunate for it means that a feedback chosen to stabilize the infinitesimal approximation also stabilizes the original nonlinear system and greatly improves the accuracy of the approximation. This is the fundamental mathematical fact that allows one to use linear models obtained by infinitesimal approximation (after being stabilized by feedback) to model nonlinear processes in the small. —Arthur J. Krener, Alberto Isidori, and Witold Respondek, “Partial and robust linearization by feedback,” in Proceedings of the 22nd IEEE Conference on Decision and Control, San Antonio, Texas, December 14–16, 1983, pp. 126–130.

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