Time constraints have limited the progress of AWT to so-called paper designs. The
following sections will detail the work accomplished by Active Wing Technologies over the
course of the Summer 2002 semester and will also provide suggestions for future work to
subsequent research groups.
following sections will detail the work accomplished by Active Wing Technologies over the
course of the Summer 2002 semester and will also provide suggestions for future work to
subsequent research groups.
7.1 Work Completed
The first half of the semester was dedicated towards background research and finding
information on supplies such actuators, controllers, and control surface materials.
Completed work is described below.
information on supplies such actuators, controllers, and control surface materials.
Completed work is described below.
Wing Stabilator Model
Active Wing Technologies, in conjunction with Dr. Stearman and Sean Hinze, had the
model reassembled and placed in room 319 of the W.R. Woolrich Laboratories building
(WRW). The model and subsystems include:
model reassembled and placed in room 319 of the W.R. Woolrich Laboratories building
(WRW). The model and subsystems include:
・Root wing-stabilator
・Hydraulic Servo Controller
・High-pressure hydraulic pump with hoses for hydraulic fluid and one pneumatic
pressure line
・F-111 model wing
・Nose and stabilator wedges
・F-111 model stabilator (never recovered from storage)
Components of the hydraulic system were recovered from Austin Hydraulics courtesy of
Sean Hinze. The system was placed on the primary mount and secured by bolts. Since
Active Wing Technologies has decided to change the power supply system on the advice of
Dr. Stearman, Austin Hydraulics was paid for their services and service was cancelled.
Sean Hinze. The system was placed on the primary mount and secured by bolts. Since
Active Wing Technologies has decided to change the power supply system on the advice of
Dr. Stearman, Austin Hydraulics was paid for their services and service was cancelled.
Research
Naoki Sato investigated limited cycle oscillation, system identification, increasing the
maximum lift coefficient, and actuator power supplies (hydraulic system, piezoelectric
system, and magnetic shape memory material.) Most of the information about LCO and
system identification was provided by the Active Wing Group's paper. Information about the
actuator power supply was found in various web sites. During the second half of the
semester, Naoki researched means of increasing the lift coefficients of fighter aircrafts. Dr.
Stearman noted that Israel had recently discovered ways of increasing lift drastically when
compared to the United States' capabilities. He centered his research on Israel's findings
on increasing lift of fighter aircrafts.
maximum lift coefficient, and actuator power supplies (hydraulic system, piezoelectric
system, and magnetic shape memory material.) Most of the information about LCO and
system identification was provided by the Active Wing Group's paper. Information about the
actuator power supply was found in various web sites. During the second half of the
semester, Naoki researched means of increasing the lift coefficients of fighter aircrafts. Dr.
Stearman noted that Israel had recently discovered ways of increasing lift drastically when
compared to the United States' capabilities. He centered his research on Israel's findings
on increasing lift of fighter aircrafts.
Basil Philip studied methods of implementing control surfaces on the F-111 wing
model. He sought information from such aeroelasticity experts as Dr. Ronald Stearman of
the UT Aerospace Department and Frank Wise, also of the UT Department. Both individuals
provided guidance, background information, and numerous additional sources of technical
information. He later developed designs in AutoCAD as possible schemes of constructing
and implementing control surfaces.
model. He sought information from such aeroelasticity experts as Dr. Ronald Stearman of
the UT Aerospace Department and Frank Wise, also of the UT Department. Both individuals
provided guidance, background information, and numerous additional sources of technical
information. He later developed designs in AutoCAD as possible schemes of constructing
and implementing control surfaces.
David Fuentes researched analog and digital control systems. David was able to
operate the Educational Servo, which he eventually determined was an analog controller.
He developed a mathematical model of the position control feature of the Educational
Servo. The process in formulating the analytical model will be value for future groups to
optimize controller designs.
operate the Educational Servo, which he eventually determined was an analog controller.
He developed a mathematical model of the position control feature of the Educational
Servo. The process in formulating the analytical model will be value for future groups to
optimize controller designs.
AutoCAD Schematic
As an aid to future groups, members of Active Wing Technologies and the Wavelet
Group transferred actual size drawings into AutoCAD. This schematic will prove useful in
the continued reconstruction and refitting of the model. Furthermore, digitizing the
schematics has distinct advantages over the deteriorating qualities of the paper form of
storing the schematics. Digital copies of the AutoCad drawings will be handed in with the
project notebook.
Group transferred actual size drawings into AutoCAD. This schematic will prove useful in
the continued reconstruction and refitting of the model. Furthermore, digitizing the
schematics has distinct advantages over the deteriorating qualities of the paper form of
storing the schematics. Digital copies of the AutoCad drawings will be handed in with the
project notebook.
7.2 Incomplete Endeavors
Some things are simply beyond our control or so unexpected that they can provide
significant barriers to progress. Due to setbacks and complications, Active Wing
Technologies has realized that some of the goals are impossible in such short time. This
section will provide an overview of Active Wing Technologies unsuccessful activities:
significant barriers to progress. Due to setbacks and complications, Active Wing
Technologies has realized that some of the goals are impossible in such short time. This
section will provide an overview of Active Wing Technologies unsuccessful activities:
・The stabilator for the model was never found. It is possible that it could still be in a
UT storage facility. If the stabilator is unable to be found, a new stabilator must be
designed and constructed.
・Active Wing Technologies never decided on a power supply to provide for wing sweep
and control surface pivoting. Several systems have been well researched and a is l
eft for future groups.
・Control surfaces were not implemented on the F-111 model wing. The research
provided in this report is a solid foundation for future groups to initialize control
surface implementation.
・Wind tunnel testing was beyond reach for Active Wing Technologies and is a future
goal for future groups continuing active aeroelastic wing and LCO studies.
・The Educational Servo was originally thought to be a digital system. However, the
Educational Servo was found to be an analog system and Active Wing Technologies
was successful understanding its modes of operation. However, ways of relating the
system to the model is still to be done.
7.3 Recommendations For Future Groups
AWT's provides the following recommendations for future groups.
Actuator Power Supply System
Research has shown the maximum frequency range of Bolding's analog system was
56Hz. AWT suspects that a higher frequency range will be necessary to utilize control
surfaces in the active wing. Before deciding on a power supply system, future groups must
do an analytical study to obtain a conservative estimate of the frequency range required of
control surfaces. The final choice of the actuator power supply must take into account its
ability to perform in the frequency range required by the control surfaces.
56Hz. AWT suspects that a higher frequency range will be necessary to utilize control
surfaces in the active wing. Before deciding on a power supply system, future groups must
do an analytical study to obtain a conservative estimate of the frequency range required of
control surfaces. The final choice of the actuator power supply must take into account its
ability to perform in the frequency range required by the control surfaces.
Control Electronics
AWT has demonstrated the angular position control and rotational speed control of
shaft on the motor of the Educational Servo. Future groups should consider using the
angular position control feature of the Educational Servo as a mechanism to control the
wing sweep angle of the wing-stabilator model. A crankshaft may be used to convert the
rotational motion of the shaft on the DC motor to oscillatory motion to drive the flaps in
future designs of the active wing. However, AWT recommends that a digital control system
should be utilized to implement the control laws for optimizing the use of the oscillating
motion of the flaps. The use of analog circuitry to implement complex control laws is
outdated.
shaft on the motor of the Educational Servo. Future groups should consider using the
angular position control feature of the Educational Servo as a mechanism to control the
wing sweep angle of the wing-stabilator model. A crankshaft may be used to convert the
rotational motion of the shaft on the DC motor to oscillatory motion to drive the flaps in
future designs of the active wing. However, AWT recommends that a digital control system
should be utilized to implement the control laws for optimizing the use of the oscillating
motion of the flaps. The use of analog circuitry to implement complex control laws is
outdated.
The formulation of analytical models of the processes involved with the active wing is
vital. Mathematical models of the control processes related to the active wing allow optimal
controllers to be designed using either the root locus method or bode plots.
vital. Mathematical models of the control processes related to the active wing allow optimal
controllers to be designed using either the root locus method or bode plots.
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