Welcome to Ola Härkegård's research web page. Here you find information regarding publications, presentations and Matlab software produced by myself and my co-authors.  If you are interested in my research, please don't hesitate to send me an e-mail.

QCAT — Control Allocation Toolbox

The Quadratic Programming Control Allocation Toolbox (QCAT) is a Matlab toolbox for exploring QP based control allocation methods. The toolbox can be downloaded from Matlab Central. The documentation of the toolbox (also included in the toolbox) can be found here.

Journal Papers

Dynamic control allocation using constrained quadratic programming
 Author: Ola Härkegård
 Journal: Journal of Guidance, Control, and Dynamics, 27(6):1028-1034, November-December 2004.
 
Resolving actuator redundancy - Optimal control vs. control allocation
 Authors: Ola Härkegård and Torkel Glad

 Journal: Automatica, 41(1):137-144, January 2005.

Conference Papers

A backstepping design for flight path angle control
 Authors: Ola Härkegård and Torkel Glad
 Conference: CDC 2000, Sydney, Australia (slides).

Flight control design using backstepping
 Authors: Ola Härkegård and Torkel Glad
 Conference: NOLCOS 2001, St. Petersburg, Russia (slides).

Control of systems with input nonlinearities and uncertainties: An adaptive approach
 Authors: Ola Härkegård and Torkel Glad
 Conference: ECC 2001, Porto, Portugal (slides).

 Dynamic control allocation using constrained quadratic programming
 Author: Ola Härkegård
 Conference: AIAA GNC 2002, Monterey, California (slides).

Efficient active set algorithms for solving constrained least squares problems in aircraft control allocation
 Author: Ola Härkegård
 Conference: CDC 2002, Las Vegas, Nevada (slides).

Backstepping control of a rigid body
 Authors: Torkel Glad and Ola Härkegård
 Conference: CDC 2002, Las Vegas, Nevada (slides).

Resolving actuator redundancy - Control allocation vs. linear quadratic control
 Author: Ola Härkegård
 Conference: ECC 2003, Cambridge, UK (slides).

 Vector backstepping design for flight control
 Authors: Ola Härkegård and Torkel Glad

 Conference: AIAA GNC 2007, Hilton Head, South Carolina (slides)

Seminars

Control allocation: What, why, and how?
 Time and place: 2002-01-24, Div. of Control and Communication, Linköping University.

Styrsignalsfördelning hos system med redundanta aktuatorer (in Swedish)
 Time and place: 2003-05-07, Dept. of Autonomous Systems, FOI.

Nonlinear multivariable flight control
 Time and place: 2003-11-13, Dept. of Automatic Control, Lund University.

Backstepping: From simple designs to take-off
 Time and place: 2005-01-27, Div. of Automatic Control, Linköping University.

Automatic control at Saab Aerosystems
 Time and place: 2007-10-24, Dept. of Automatic Control, Lund University.

The Skeldar V-150 flight control system

 Time and place: 2007-11-08, Div. of Automatic Control, Linköping University.



Thesis

Backstepping and Control Allocation with Applications to Flight Control
 Defended: May 23, 2003
 Opponent: Marc Bodson, Univ. of Utah

 

PhD thesis based on the conference papers above published during 2000 - 2002. Features an aircraft primer, introductory chapters on backstepping and control allocation, as well as an overall evaluation of the proposed flight control system using the Admire simulation model.


About the Author

Ola Härkegård recieved his M.Sc. in Applied Physics and Electrical Engineering in 1998 and his Ph.D. in Automatic Control in 2003, both from Linköping University, Sweden. Since 2005 he is employed by Saab AB, Linköping, Sweden, where he works in the Flight Control System group.