Image: 1st Run
AVC was great fun and even though I went for broke on the last run and lost my copter, it was well worth it. I learned a lot about copter navigation. The latest code includes all of the updates, which is being tested now by Jack Dunkle.
Run 1 went really well. In turn 1 you can see the copter overshot the waypoint. Crosstrack error pulled the copter back to the desired path and kept it from being blown into the building from the high winds. The sonar altitude hold was working really well. Later the wind would pick up and make the copter go higher than sonar, which made it susceptible to an altitude hold bug. More on that later...
Each waypoint was hit perfectly, even though the copter tended to go too fast (17mph) and overshoot. At Turn 4 the copter buzzed the crowd at about 6 feet. Thankfully everyone ducked. Then the copter went to position hold for 4 seconds to settle down before going to land. Unfortunately this area was really windy and the copter was blown towards a tree. I had to abort by popping the copter up by 50 feet.
At that point I thought I would try and finish the mission by landing in Auto. Unfortunately, I had set the mission to reset on entering Auto. It began to re-fly the mission at about 100ft now. It hit turn 1, then a gust of wind grabbed it on the way to turn 2. That wind was 50MPH.
Run 2 went bad quickly. The wind shifted and lifted the copter above sonar range almost immediately. The baro alt hold bug kept it from coming back down properly. The wind above the building was gusty and blew the copter to the front of the building. Then a loose battery fell out of the copter... Because the motors were now free spinning, it auto_rotated to an upright landing from > 100 ft. The landing gear - plastic heli skids were partially broken, but it was otherwise in perfect shape. I should've taken the hint and called it a day, but run three was my last chance to finish.
It looked identical to run 2, except the copter kept climbing and the high winds just swept it away.
Anyway, much learned and code updated. I am trying a rate limited version of waypoint navigation. The idea is that the copter will want to travel at a certain speed towards the waypoint. This enables it to fight high winds by flying steep angles. It will also make overruns more predictable.
Once these new updates are tested, I'll open up the code to a public beta.
Some photos posted by Mark Grennen:
Love this one:
I actually recovered the lost copter when I returned to Sparkfun this year to compete. It somehow found it's way back to me, thankfully.
The flight was doomed form the start. Once it cleared the buildings it was swept away by 50-60 mph winds. I clocked it with the GPS going up to 69mph at one point. Here's the recovered data log plotted in Google Earth.
This was very early software that was literally more bugs than good code. In fact, the morning of the race was the first time it ever flew autonomously. We've come a long way thanks to Tridge and Randy and others, not to mention the Flash SIM I built to develop the current flight management system. Looking back at this flight I'm amazed it actually worked at all.
If you've not flown the latest 2.7.3 you're in for a treat.