T-Wing Video Clips

Free Flight with Transitions: 30/August/2006

The video below shows a free flight performed with both transitions on 30/August 2006. The vehicle performed the first transition fully autonomously and navigated to the first horizontal waypoint and turned on to the second fully autonomously but was then put in a semi-autonomous mode due to excessive altitude loss in the turn (due to a small problem in the flight controller – since fixed). With the pilot supplying high-level guidance commands for the vehicle’s low-level controllers, the vehicle was transitioned back to vertical flight and recovered safely. In the video the following aspects are seen:

v Vehicle climbs up to a waypoint at 100 ft;

v It then continues climbing to a further waypoint at 300 ft;

v It then transitions fully autonomously away from the wind in the correct attitude. During the transition it loses approximately 3 metres in altitude;

v It then navigates to the first horizontal waypoint and turns towards the second autonomously;

v During the turn the vehicle loses significant altitude due to a small control system error (excessively tight saturation limits on some integral states in the pitch-rate controller);

v The pilot takes over high-level guidance and brings the vehicle back towards the runway (supplying pitch angle, and bank-angle commands);

v The ground-pilot commands the vehicle to perform a horizontal to vertical transition which it does in about 50m of altitude.

v The video is also cut to shorten the time of the descent portion of the flight (about 2 minutes in the actual flight)

v The vehicle lands in a vertical attitude.

Transition Flight 30Aug2006_ (~12MB)

Free Flight with Transitions: 1/August/2006

The video below shows a free flight performed with both transitions on 1/August/2006. The vehicle was accidentally put into a fully manual mode [due to bad ground-station ergonomics] during the flight and lost control, but was recovered in a semi-manual mode and landed without a scratch. The video has been edited to delete the unintended control departure region. In the video the following things are seen:

v Vehicle climbs up to a waypoint at 100 ft;

v It then continues climbing to a further waypoint at 300 ft;

v It then transitions into the wind on its back and rolls right way up while in autonomous mode;

v At this stage the manual switch was inadvertently hit and the vehicle departed controlled flight;

v The video resumes with the vehicle recovered in a semi-manual mode;

v The ground-pilot commands the vehicle to perform a horizontal to vertical transition which it does in about 50m of altitude.

v The video is also cut to shorten the time of the descent portion of the video (about 2 minutes in the actual flight)

v The vehicle then lands in a vertical attitude.

Transition Flight 1 August 2006 (15.08 MB)

Model Predictive Control Flights 28/July/2006

On 28^th July 2006 the vehicle completed its first 100% successful Model Predictive Control (MPC) Flights on the tether test-rig. During these flights the vehicle performed the standard “+” pattern while in hover-mode vertical flight. The vehicle used an MPC algorithm looking ~2.5 seconds into the future to determine the optimal control to apply at any given point in time. The particular manifestation of the MPC algorithm used here has been developed by Peter Anderson as part of his PhD studies and runs on the 400MHz Celeron flight computer. For some of the predictive flights the vehicle was flown with an ultrasonic wind-sensor to capture the relative wind-information.

Model Predictive Control Flight 28/July/2006: ultra-sonic wind-sensor on nose in picture (not video)

Fully Autonomous Tethered Testing with New Avionics: November 2005

The videos below show the vehicle performing a fully autonomous flight from takeoff through to landing. During this flight the vehicle passes through a total of 26 way-points before landing autonomously. The waypoints consist of the following maneuvers:

v Climb 10 ft and hover.

v Move in a Cross-Pattern (“+”) with 8 ft legs in North, then South, then East and then West directions with belly facing North. This demonstrates vertical translations in directions aligned with major vehicle axes.

v Reorient belly 45 degrees to point North-East.

v Repeat Cross-Pattern with 8 ft legs in North, South, East and West directions to demonstrate vertical translations at oblique angles to the normal vehicle axis system.

v Reorient Belly pointing North.

v Perform clock-wise hesitation vertical role, stopping at each major compass point (NESW).

v Perform similar anti-clockwise hesitation vertical role.

v Climb to 12 ft altitude;

v Descend to 4 ft;

v Land.