Welcome to
the T-Wing vehicle home page. The T-Wing is a tail-sitter technology
demonstrator UAV that is being jointly developed by the University of Sydney and an Australian
company, Sonacom
Pty Ltd. The T-Wing vehicle concept grew out of vehicle optimization
studies conducted at the University during 1995-1999 by Dr Hugh Stone,
for his PhD dissertation. Although in some respects similar to the Boeing Heliwing vehicle of the early 1990's it is fundamentally
different in a number of respects. Some of the differences are:
Ø
The
use of control surfaces submerged in the slipstream of the vehicle's twin
propellers to provide control during vertical flight (similar to the
tail-sitter vehicles of the 1950's) as opposed to the use of standard
helicopter cyclic control;
Ø
The
use of a canard to balance the aft wing and allow greater freedom in CG
positioning; and
Ø
A
different fin and landing gear arrangement.
The T-Wing
has a wing-span of ~2.1m and a MTOW of ~30 Kg. It is powered by twin 78cc 3W
2-stroke engines that turn 23 inch diameter propellers. The vehicle is
controlled by an onboard PC-104 computer stack that drives all the servos and
accepts inputs from the GPS and IMU sensors. The vehicle communicates with the
ground via Radio Modem Serial Data link. So far the T-Wing has been flown in
hover mode both manually (very briefly!) and under automatic control using
Command Augmentation System (CAS) controllers. For hover mode, these map pilot stick inputs to velocity commands:
Ø
elevator
and rudder stick inputs become translational velocity commands;
Ø
aileron
stick input is treated as a (vertical attitude) roll-rate command; and
Ø
throttle stick input maps to a vertical velocity
command.
Tethered
hover testing has commenced on the second airframe and on
Tethered
Hover testing resumed on 1st March 2005, with a total of 4 tethered
flights exploring different vertical flight control modes and testing the integration
of a new more accurate GPS receiver, pressure sensor and upgraded flight and
ground-station software. Besides the standard vertical velocity mode tested
previously, the vehicle was also tested with vertical angle-based controllers
as well as rate-based controllers.
As of November 2005 we have installed a
new avionics system which gives ~ 20 times increase in accuracy for the vehicle
position, velocity and angle states. This has allowed us to conduct fully
autonomous vertical flight testing with the tether test-rig. We have also been
able to successfully fly the vehicle in 10-15 knot winds in both autonomous and
vertical velocity guidance modes.
From May 2006 we replaced the 3W-78CC engines
with Desert Aircraft 100CC engines to counter weight growth with heavier
avionics and deterioration (with age) in the 78CC engine performance.
Between 1st and 30th August/2006
we have performed three transition flights, each involving at least one set of
transitions between vertical and horizontal flight.
Videos of
these flight tests are given on the Video page here.
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Last
revised: Thursday, October 4th 2006
This page
has been visited times since 19th Sept 2002.