Copter 3.7.0-dev Geofence Inconsistencies

My team and I are running Copter 3.7.0-dev on Pixhawk 2.1 Cube Black and an OCTO-X frame. We have observed several issues when implementing a Geofence in MissionPlanner. Two different warnings show up upon booting: “fence requires position” and occasionally “Geofence breach” and continue to show even after all sensors and EKFs appear to be settled (i.e. both warnings will show while the OCTO is on the ground in an open field).

For background, the OCTO is using the Here+ GPS/Compass & RTK system (running ublox FW version 1.40) and has very good HDOP (~0.6-0.7) and visible sats numbers (19-24). In addition, the EKF is given time to completely settle as well. These warnings prevent arming and seem to occur particularly when “old” geofence and polygons files were used to draw/upload geofence boundary. Switching the geofence type from “polygon and altitude” to “circle and altitude” does not stop the flags leading us to believe the input file isn’t the problem by itself. Defining a new geofence before every flight wouldn’t be the worst thing, but it doesn’t work everytime. The following process seems to give the best results (it’s worked twice).

Wipe geofence and mission–>reboot pixhawk–>reboot mission planner–>reconnect and reboot pixhawk–>redefine geofence.

It is unclear if this actually works or we just got lucky and managed to change something on accident along the way. Any help or insight anyone could give would be much appreciated. I can attach logs if that would help. And, of course, if I’m in the wrong place please let me know. Thank you in advance.


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It’s most likely that the GPS fix is not stabilised - I see those errors all the time with 3.6 and earlier.
If you don’t like them wait till GPS has a 3D fix or HDOP of Less than 1.0, then reboot without powering off.

A few monthss ago GPS was going crazy, and with the craft just powered up and sitting on the ground the HUD was giving a great display of its full capabilities with the GPS reporting the craft moving all over the district in just seconds.


it sounds like a bug of some sort although I’ve been playing around with polygon fences (for object avoidance) and haven’t seen this particular issue but that doesn’t mean it’s not a real problem.

This is all Copter-3.7 though which is under active development and the code changes each day and it hasn’t gone through beta testing though so bugs are possible and even likely.

We hope to start beta testing of Copter-3.7 within 6 weeks and I’ll be actively answering support questions and getting to the bottom of issues from then on.

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Thank you for the help! My team and I will continue to test the daily builds and would certainly enjoy the opportunity to help where we can with the beta testing for 3.7.