We invite fans of our Low Orbit Helium Assisted Navigator (LOHAN) project to raise a glass or two today to UAV specialist 3D Robotics, which has very kindly agreed to offer our Vulture 2 spaceplane a brain transplant in the form of the mighty Pixhawk autopilot.
As LOHAN regulars know, our aircraft is already temporarily fitted out with the company’s ArduPilot Mega (APM) 2.6:
This impressive piece of kit recently guided Texan Larry Grater’s North Texas Near Space 4 (NTNS 4) aircraft to the ground from a dizzying 30,780m, proving 3D Robotics’ autopilots have the Right Stuff for our audacious stratospheric mission.
The APM also triumphed in the 2011 UAV Challenge down in Oz. A member of the winning team was ArduPilot (the fixed-wing APM flavour) lead developer Andrew Tridgell, who’s a bit of a celeb in the coding world for his work on Samba.
Andrew got word of LOHAN, and dropped us a line offering his support. He also had a chat with 3D Robotics suggesting we might benefit from the hot-off-the-press Pixhawk, and the company marvellously agreed to send a couple over just as soon as it’s beta tested.
Good news indeed. The Pixhawk has a few new bells and whistles which Andrew says will benefit the mission, including a new digital airspeed sensor and enhanced data recording capability.
At the autopilot’s heart is a 32-bit ARM Cortex M4 processor running NuttX RTOS. Andrew suggests we connect the unit to the Vulture 2‘s Raspberry Pi – principally on board to control a nose-mounted Picam.
He asked: “Do you want to run MAVProxy* on the Pi as a connector to the autopilot telemetry? I run embedded Linux boxes on my planes and actually compile the autopilot firmare on the Linux boxes, and upload, etc, all within the aircraft.”
Well, if that isn’t enough to get LOHAN team member and Pi guru Dave Akerman licking his lips in anticipation, we don’t know what is.
As soon as the Pixhawk flies in (the traditional tip of the hat to 3D Robotics’ Craig Elder for sorting), we’ll bring you details on the beast, and just how we’re going to integrate all the onboard systems. In the meantime, we can continue working with the APM 2.6, which runs the same basic software.