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Here is a video clip from Paul Mather and my last minute entry into the SparkFun Autonomous Vehicle Competition.



The day before the competition I realized that the DIYDrones community had an unused entry into the competition and I had a second UAV ready to go, so I recruited Paul Mather as a teammate and we became team "Plan B", flying a SkyWalker with ArduPilotMega. It was quite windy and gusty as you can see. This is the conclusion of the first round flight, conducted 100% autonomously, which would have scored well. The plane was getting blown around badly on final approach, but would have made it around the pine tree and right into the landing zone had it not been for impact with the light pole visible around 0:15 :(

Some other details from the event: I believe that Paul and I, and Chris Anderson, were the only competitors flying APM powered planes - Paul and I had two teams, one with the SkyWalker and another with a SkyFun. Wind was a problem for the Skywalker. It certainly could have flown much better, but we were flying it pretty slow (ranging from 15 to 9 m/s) due to the small course and small landing area. The first run we clipped the light pole as shown in the video which was heartbreaking because it could have been a 100% autonomous landing into the very small landing zone on a windy day. On the second run the SkyWalker went into the pine tree that shows so prominently in the video and lodged very high. Fortunately a brave Sparkfun employee climbed up and dislodged it. It was no longer pretty after two crashes, but tape and lots of CA glue got it airworthy. On its third run we skipped the auto landing and got it on the ground quick enough after crossing the finish line to secure 2nd place.

The SkyFun performed great, but with all the pressure and chaos of the event I accidentally messed up the mission planning for two of the three runs and had it trying to climb over 1500 meters. Confusing absolute and relative altitudes in Colorado makes a big difference. That was embarrassing. The one successful run was really fun. We used a catapult launcher that was actually controlled by APM - having APM control the catapult was necessary to qualify for the autonomous takeoff bonus. A quick release connector on the back of the SkyFun was connected to a cable on the catapult controlling the release mechanism. After the release was triggered APM sensed the high acceleration of the catapult and as soon as the acceleration stopped APM fired up the motor. It worked flawlessly all three rounds. Unfortunately, on the one fully successful flight (100% auto from catapult launch through landing) the wind shifted around and we had a tailwind for the landing. A SkyFun with a tailwind will only come down so fast, and we glided past the landing zone and didn't get the big bonus.

Many thanks to Paul, and to my brother David, for all they did!  They both just made things happen.