Missouri S&T AESS UAV Team

We arrived in Brisbane on the morning of Friday September 19th after 18 hours of flying and traveling 8000+ miles.  We picked up our rental car, and with maps in hand (or on the laptop), we headed for a hobby shop to pick up some glow fuel and landing gear wheels.  At the hobby shop (Hobbyrama) they were even kind enough to let us borrow one of their 36MHz RC transmitter/receiver pairs since we could not use our 72MHz system for our failsafe.  We then headed off to Kingaroy where the competition would take place.

The view out the window of the Boeing 747-400 of the sunrise over the Pacific Ocean

After 2.5 hours of driving we arrived at our destination, Kingaroy, the peanut capital of Australia.  We checked into our hotel and drove over to the airport to get an idea for the competition site.  We then proceeded to rebuild the airplane in our hotel room, as we had to remove the engine and the empennage in order to fit it into crates.
Bright and early Monday morning we arrived at the competition site and unloaded our gear into one of the event tents.  We also had our oral presentation that morning where we discussed our design and gave an overview of our system as a whole.   The oral presentation went well and we also turned in our technical report and documentary to the judges.  The next order of business was to pass the safety inspection.  This included checking all control surface linkages, equipment mounting, structural integrity of the airframe, etc. That afternoon we were also able to perform an engine run to ensure that everything was reassembled correctly, during this test we found an air leak in the fuel system, which was quickly corrected.

Our competition paddock

The first day of competition was a success, everything going smoothly.  The organizers did a great job of keeping everybody informed of what was going on and ensuring that we had everything that we needed.  The following day (Tuesday) was the high school Airborne Delivery Challenge.  We arrived early in the morning and powered on our UAV, which we had left in the tent overnight.  We quickly noticed that something was wrong, the onboard computer was acting flaky and the 2.4GHz WiFi card in the onboard computer did not want to function properly.  Much of the morning was spent trying to remedy that problem, trying everything we could possibly think of.  Eventually early in the afternoon everything was sorted out, the condensation on the components in the morning may have been the culprit, the lesson learned from that was to not leave our electronics outside overnight.

Troubleshooting the onboard computer on the UAV

It was impressive to see all of the aircraft that the high school students had built, all of them equipped with wireless video and many of them were also equipped with “co-pilot” wing levelers.  The level of enthusiasm was also impressive.  It was definitely interesting to watch the teams’ mission attempts, unfortunately many of the attempts resulted in crashes, with the 2.4GHz RC radios being the prime suspects. There was also one really close call with a helicopter that took off, and shortly after takeoff the pilot lost control and it flew up over the sponsor tent and curved around and crashed right by the grandstands, barely missing some spectators, it then thrashed around on the ground for a bit before finally dying.

By late afternoon we had our system up and running and were ready to perform our demonstration flights.  The winds were quite high that afternoon, around 10-13 MPH, and the grass around the paved runway was not as smooth as we would have liked (we prefer grass takeoffs since it’s easier on the propellers than tarmac in the event of a prop strike).  After a couple unsuccessful attempts we were able to get the UAV in the air under manual control, we then switched over to autopilot control and flew a few circuits and dropped the water bottle to demonstrate our system.  The autopilot was not navigating very well and was oscillating in pitch, this was probably due to the fact that we had only had two days before leaving for Australia to tune our control loops to the new airframe and some of the gains were off.  But the purpose of this flight was to demonstrate to the judges that we could perform safe manual and autonomous flight, which we did.

The third and final day of competition included the actual mission attempt at finding Outback Joe.  Early in the morning we gave Procerus a call and sent them a telemetry file to try and figure out why we were oscillating in pitch and why navigation performance was not very good.  After a short discussion the cause of the problem was identified and the judges allowed us to perform a second tuning flight before our actual mission attempt.  We went out to the field to set up our gear for our second flight and we started up the engine and it turned out to have trouble idling.  After about an hour of messing around with the low-speed idle and the high-speed needle we got it working reasonably well and got the UAV in the air.  But not without several failed attempts at taking off in the windy conditions.  Once the UAV was in the air, we quickly adjusted the parameters that needed to be modified and it then handled admirably, especially considering the amount of wind that it had to fight against.

Removing the wing from the UAV and preparing to refuel

The tuning flight lasted approximately 15 minutes and we brought the UAV down and prepared for the actual mission attempt.  This included filling up both of our fuel tanks and recharging the LiPo batteries for our electronics.  In the mean time Team Telemaster made their attempt at the mission.  They took off and began circling above, and appeared to be having trouble with their system, then all of a sudden the UAV started circling down, clearly the flight termination mode had engaged.  It was definitely disappointing to see their UAV circle down into the ground, fortunately for them; it was a relatively “soft” landing, with only minor damage to the airframe.

We were up next; we went out to the field and the clock started (we had an hour for our attempt at the mission).  We took our time to make sure everything was set up and configured correctly and started up the engine.  By this point in the afternoon the winds had picked up even more than earlier in the day, wind readings were about 12-15 knots steady, with gusts.  We taxied down the field and prepared for takeoff.  The engine revved up and the UAV started down the field parallel to the tarmac runway, the wind started to push the airplane on to the tarmac and then as the wind picked up a wing tip caught on the tarmac, and the airplane flipped over on it’s back.  We had had this happen on grass before so we ran over to flip it over and start it up again, but when we got there we knew something was wrong.  The fuselage was broken in two.  The judges deemed the damage too structural to attempt repairing it in the one hour allotted for the mission attempt.  It was over.  We were so close, had we gotten in the air, we would have almost certainly found Outback Joe.

The UAV after the crash

We ended up receiving second place overall, with Team Telemaster placing first, and QUT (Queensland University of Technology) placing third.  Overall the competition was definitely an excellent learning experience, and the camaraderie between the teams was excellent, we all helped each other out and offered up tools and help when needed.  The judges were also very helpful and understanding when we had issues, allowing us to resolve the issues and helping us in any way that they could.  The next competition should definitely be much more competitive, it was rather unfortunate that all three teams crashed this year, especially considering any one of the teams could have successfully completed the mission.

Accepting the prize

And now for some pictures after the competition:

Note: Sorry for the late update, I was really busy catching up with school after returning from the competition and then forgot to post an update…

I would like to thank all of our sponsors that have helped us get to this point, and will help us finish strong.  Our current list of sponsors includes IEEE, AESS, Boeing, Procerus, and Garmin.  We’re still a little short on funding for the year, but we’re almost there.  If you or your compnay may be interested in sponsoring our team in anyway (financially, with equipment, with publicity, etc.) please contact David Erdos at sponsors@aessuav.org for more information.  Also, check back next week for another update (we plan on doing some more testing early next week).

Starting January 1st, 2008, the University of Missouri-Rolla will be officially known as the Missouri University of Science and Technology (Missouri S&T), more about that here. As a result of this we will also be changing our name to MS&T AESS UAV Team.

Since our crash several months ago we have been developing a new wing specifically designed to meet our requirements for our mission. Since speed is high priority in our mission we have designed a wing that is smaller and more aerodynamic allowing us to fly faster in order to cover the search area in less time. Two of our excellent Aerospace Engineers have been working on the design of our wing, performing various calculations and CFD (Computational Fluid Dynamics) analysis. Unfortunately due to everybody’s busy schedules we have been slightly behind schedule in the construction of the new wing, but we plan to be back in the air by late January or early February. Below are a few images of our current design and a screenshot of our UAV flying in the X-Plane flight simulator.

We are also currently in the process of evaluating our strategy for acquiring and processing the images, we are working to decide what approach would be best suited and the most efficient for our mission. Our second revision of the power distribution board for the UAV is also nearing completion (see below).

Over the summer we have come to the conclusion that we will not be ready to compete in this years UAV Challenge due to a lack of progress, which is understandable considering we only had about 2 months together as a team before the summer break to build the UAV.  Instead we plan on competing in next year’s competition, by then we should have a mature platform that will be tested and ready to perform the mission.

Currently our next goal is to get the UAV put back together since all of the electronics were removed over the summer to do some testing.  The current goals are to have onboard video installed within the next few weeks, and get the control loops tuned better for autonomous landing.