After gaining confidence in 3.0 (RC5) during the AVC in Boulder, I decided to try some longer flights. Golden gate park is one of my favorite places to fly and one of the few areas of San Francisco where the city isn't overrun by housing. So I decide to run a 3 mile cross-country flight from one end of the park to the other to perhaps be the first to do so completely autonomously (that I know of.)
I picked out two fields at either end and used Google Earth to generate my waypoints by exporting a KML and editing the path in BBEdit (OSX text editor.) I choose this route because I wanted to ensure my altitudes were following the 54m incline from the coast to the landing zone and all of the hills (up to 70m) in between. I also went to the fields and measured the altitude error in Google which turned out to be about 20m in highest point and the trees which were 30m in some places.
Next I realized I needed a chase car so I enlisted the help of Wolfgang Kandek, his son & Jeff Vyduna (flight 1) and Tad Whitaker & John Bertrand (flight 2). For safety we choose to fly around 8:00am Sunday morning when the roads were closed and very few people were in the park. We followed the copter along MLK and watched it via FPV and telemetry which easily stayed connected the entire flight.
The first flight unfortunately had a motor wire failure and fell from the sky. The vibrations from probably 50 flights had work hardened one of the solder joint between the ESC and a motor wire. A better flight check would have caught the issue. Luckily It fell harmlessly in a bush and not in a tree or street.
The second flight after minor repairs went off perfectly. The copter took off and stayed to about 50m above the ground the whole time. The mission was set to fly 13m/s or about 30mph. A 3s 3300mah NanoTech battery easily made the trip in under 8min including the takeoff and landing. I could have traveled at least a mile farther with the excess flight time.
The accuracy of the flight path is stunning and a testament to the new inertial system developed by Randy and the Arducopter team. Looking at the path in Google earth, I can see cm accuracy in XY. Amazing! Also the transition between waypoints has a nice flow. The Yaw transition however was not very good. It's quite sudden and jerky between waypoints. I am considering a patch to use acceleration and deceleration of Yaw to give a smoother feel for the GoPro camera.
Here is the full path:
The landing zone:
Smooth WP transitions:
The KML file:
And the video of the second run (sorry about the Fog!)