Development and Flight Testing of a 
UAV with 16 Segmented Aileron Surfaces 

- Principle Investigator - 
Mujahid Abdulrahim - mujahid@ufl.edu
-Faculty advisors - 
Dr. Rick Lind - rick@mae.ufl.edu  
Dr. Peter Ijfu pgi@mae.ufl.edu  

Last updated: Sept. 10th, 2003

Publications (complete listing):

• Flight Dynamics and Control of an Aircraft With Segmented Control Surfaces [PDF]

  ABSTRACT Flight researchers are increasingly turning towards small, unmanned aircraft for achieving mission objectives. These aircraft are simple to operate and offer numerous advantages over larger manned vehicles. In addition to being light, inexpensive, and readily available, they are also more versatile in that they can be used for flight experiments that are either too risky or uncertain for a manned flight test program. One application of unmanned vehicles is in the area of increased control authority research. This paper presents the preliminary stages of one such application, where an existing UAV is modified with 16 independent wing control surfaces. These surfaces are used in place of conventional ailerons for roll control and as a supplement to rudder, elevator, and flap controls. Instrumentation and sensors on-board the aircraft allow complete characterization of the flight dynamics. A traditional control system is replaced with a microcontroller that commands each aileron segment independently. Various modes of actuation can be implemented to improve roll, pitch, and yaw response, minimize induced drag, and provide numerous levels of redundancy. The results indicate that the segmented control surfaces can be configured for a superior level of control.



• Investigating Segmented Control Surfaces for Full Authority Control of a UAV [PDF]

  ABSTRACT Aircraft control has progressed considerably since the early experiments of the Wright brothers in wing twisting. A diverse range of control schemes has since been developed to manage various aspects of the flight environment. A modern airliner, for instance, uses dozens of different control surfaces. Such highly specialized controls prohibit high performance throughout the wide flight envelope and offer little for redundancy. The concept of a morphing aircraft, however, would address these issues by allowing complete control of the aircraft structure for both primary control and multi-role situations. This research investigates a discretized approach to morphing the trailing edge of the wing. A UAV was modified to incorporate simple morphing capability and was flight tested extensively. The resulting system identification indicated that the lateral and longitudinal dynamics could be accurately modeled using simple linear-regression techniques. Both differential and collective deflection of the wing segments showed potential for full authority control over the aircraft. Using the models generated, controllers for the aircraft are being developed to fully exploit the potential of a highly configurable control system.

Conference Presentations (Powerpoint):

Flight Dynamics and Control of an Aircraft with Segmented Control Surfaces
AIAA SE Regional Student Conference
April 2003
Kill Devil Hills, NC

Investigating Segmented Trailing-Edge Surfaces for Full Authority Control of a UAV
AIAA Atmospheric Flight Mechanics Conference
National Student Paper Competition
August 11th, 2003
Austin, TX

Presentation Video:

Sunset Flight Test (27MB mpeg) This video shows the elements of a typical flight test, including startup procedure, takeoff, on-board footage, flight maneuvers, landing, and data recovery	Aileron control pulses (13MB mpeg) On-board video looking over the left wing panel shows the roll response from a uniform differential deflection of the servo array.
Individual-Differential pulses (27MB mpeg) On-board video overlooking the right wing panel.  This clip shows individual deflection of the wing segments to produce a roll response.  Each segment is actuated individually throughout this flight test.	Collective deflection pulses (5.1MB mpeg) An attempt at longitudinal control effecting.  The entire servo array moves uniformly to change the pitching moment of the wing.  This results in some degree of control over the pitch of the aircraft in flight.
Rudder pulses (5.6MB mpeg) This series of clips shows an rearward view from the camera looking over the tail feathers.  Once the aircraft is trimmed, the rudder is deflected or pulsed in both directions.  The response of the airplane is a coupled roll-yaw behavior.	Elevator pulses (5.8MB mpeg) Another look at the tail, this video shows the second longitudinal control pulse test.  As with all the maneuvers, control input is generally small to prevent the aircraft from diverging.

Flight data from a reverse Cuban-eight maneuver

Adventures in flight photography - a pictorial collage of Mig-27 shots

Installation detail of wing actuators