Q: In a nutshell, what's the AttoPilot project about?
The AttoPilot is about bringing a full-function powerful autopilot to a larger crowd, for many of whom "DIY" is not their interest, just something they can buy and use. I myself wanted to buy a hobby autopilot in late 2005 knowing nothing except "I'll look on the Web, surely I'll find something".
I was SHOCKED that the cheapest unit that met my basic requirements costs $900 (the UNAV NAT
). Everything I found was either really heavy/expensive, or home-made looking. I knew there was much room to improve, even for somebody like me with no idea (at the time) how to make something like an autopilot that I would let fly my airplane.
So, I started out only with ideas of how it "should" work with no ideas of what roadblocks the hardware/coding might have in store for me. I think this naiveness was an asset. Features of initial release hardware rev (other versions coming, some smaller):
Low weight: 36 grams (1.25 ounces) is the TOTAL added to your airplane including GPS and antenna and sensors. 50% of that is just the CoPilot head and cable (18 grams). The IMU version is lighter, mass = 22 grams total system. [note: the picture here are of prototype hardware]
Small size: Atto is a single package of about 25x20x10mm with right-angle header connections to the servos, like a small 6 channel Rx. The only external pieces are the GPS module and CoPilot sensor head.
Rx interface: Atto reads the channels from your Rx through the servo jacks, no soldering to the Rx board. Atto is designed to read 3V/5V logic signals automatically, and ANY pulse order from the Rx, be it overlapping or serial, Atto doesn't care. It reads with precision to < 1us.
Integrated data logging to micro SD card, and USB jack for interface to your PC. Currently in testing, I have about 20 parameters logged at user-configured sampling rate, up to 5 Hz. You can view the flight history in Google Earth as a 3D path, plus analyze many details of the flight, including how the autopilot performed, and what it was "thinking" at the time. You can use this data to know precise location of aerial photos.
100,000 waypoints that are 3D. Make your flight plan graphically in Google Earth, then use simple formatting application in Windows to hand-edit the path, and add XOR checksum to each line. The finished file goes on the SD card via USB jack.
No limit to distance between waypoints, or to how far the unit can fly from starting point. Proven to work in all hemispheres (NS, and EW of the prime meridian)
Intergrated static and dynamic barometers with special data filtering routines, for baromteric altitude control (that is corss-referenced against GPS altitude) and pitot tube airspeed.
Currently 8 triggerable events at each waypoint. User-configurability what the 8 events are, be it position of auxillary servos, etc... Useful for Aerial Photography.
Drives up to 6 servos, with user-configured mixing of servo outputs (for V-tail, elevons, or even just 2 seperate aileron servos)
Telemetry jack to the XTend modem by Maxstream. This is currently being developed but is on track. Working now is the downlink to moving map software, but goal is 2-way com to take R/C control at long range, upload new waypoints, and issue commands such as RTL.
Stability/attitude control: FMA's CoPilot thermopile head is used in a special way: By fusion of the thermopile data with barometer and GPS data, a very robust and self optimizing system is created. Auto trimming during flight, auto gain adjustment.
Pricing - I can't comment on this yet, as I don't know what it will cost to have these made by a professional assembly house (I will not sell a hand-made AttoPilot, people deserve at least the same quality as is in their TV remote). I can tell you that my desire is to sell something 20x more functional than anything else currently available, and for about HALF the price of other hobby autopilots. Many people are not interested in DIY, but rather plug-and-play. Of course, there is much more to a drone than the autopilot, so I think these people still fall in the spirit of "DIY Drones".
Schedule of availability: Summer 2008. Beta testing is still going strong with rapid roll-outs of firmware upgrades, and hardware add-on PCBs that will be integrated into final production version.
Q: What's the origin of the name "AttoPilot"?
Well, you have micro and pico pilots, and they refer to the SI notation for millionth and trillionth (1x10e-6 and 1x10e-12), respectively.
I have talked to Curt Olson off and on, so I know that guys like him don't need the tiniest autopilot, but for people that do, I'll offer something smaller than the "pico" pilot. "Atto" is SI notation for 1x10e-18, or a millionth of a trillionth. Also, Atto is like Auto, so instead of an auto-pilot, you get the name Atto-Pilot!
BTW, the Beta Attopilot uses pretty big DIP processor and breakout boards from sparkfun.com, but even
then with GPS the unit comes in at 1.6 ounces, which is already HALF of the Pico Pilot's assembly of PCBs to make their complete system. By going to a NEWER GPS besides the ETek unit and having Atto be a 100% SMD [surface mount device], the mass drops down to the figures I quoted, in the < 1 ounce range.
In addition, I have a 6 gram "shrink" version with integrated Kalman IMU on the same PCB with integrated GPS and antenna and
[You can read more about this project and its inception in these two RCGroups threads. Latest beta details. The origin of the project emerged in this thread]
other sensors. This version is suitable to fit INSIDE the wing of a tiny MAV (like a 6" span plane). This is a work in progress, but I suppose my point is that my autopilots will TRULY be Atto in sized over this coming year.
[Part 1 of the interview is here. Part 3 is here.]