Great news from Randy and the ArduCopter team:
Over the past month or so a few of us have been experimenting with using the Pozyx1 system (based on the decawave DWM1000 chip) for non-GPS navigation.
We've made quite good progress and it's just been integrated into ArduPilot master and should go out with Copter-3.5 in a few months. You can see a video of a flight using Pozyx here1:
The system works by setting up 4 anchors (aka "beacons") in a rectangle (see image below). Then a "tag" is mounted to the vehicle (see IRIS above). This tag is a pozyx sensor plus an arduino uno which runs a fairly simple sketch which tells ArduPilot's the length of the sides of the rectangle and the vehicle's distance to each beacon. ArduPilot's EKF has been enhanced to consume this information and come up with a position estimate.
Some extra info:
- the range of the sensors seems to be a bit longer than 50m.
- there's some indication that the system suffers from multipathing so it really needs a clear line-of-sight from the vehicle to the beacons.
- so far we use 4 beacons. The minimum is 3, the EKF supports up to 10.
- the hardware is quite bulky but we hope smaller hardware will be manufactured by someone eventually. There seems to be interest from several groups to do this.
For developer who want to experiement with the system, we've created a fairly detailed setup wiki page here1.
Some credit for the work so far:
- idea to use the DWM1000 was brought to the team by long-time ArduPilot developer Jonathan Challinger
- strategy to use Pozyx and first GPS_INPUT implementation by the Drone Japan School1 members including Kitaoka-san, Matsuura-san and Murata-san.
As per usual, if you're interested in getting involved with ArduPilot development, you can find many of us on Gitter.
Comments
My sentiments exactly. We have been looking at this for over a year ourselves and I have just been absolutely amazed that no one has been developing this exact concept ever since the Pozyx and the DWM1000 units became available.
I would think this would be perfect for tracking the exact position of FPV Racing drones around the race course. Need I say any more...
This is such an amazing concept brought up for people to take note of. My skull feels stomped in how nobody seems to be extremely excited and interested in features like this. This positioning feature has been on my mind for years and I didn't even know there was a solid effort being worked on by such wonderful talent.
I feel like a humiliated cheerleader with the emptiness on so many articles posted on this site. The implications of so many things and how the lights don't seem to be turning on :(
Cheers Chris