Losing hedgehog tracking after 0.6m

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sdr
Posts: 4
Joined: Mon Jul 10, 2017 10:23 pm

Losing hedgehog tracking after 0.6m

Postby sdr » Mon Jul 10, 2017 10:42 pm

We have 4 stationary beacons mounted horizontally to a plate in a rectangular pattern about 0.3m off the ground. This arrangement is able to track the hedgehog when it is close to the stationary beacons but the tracking drops out at distances greater than 0.6m y or 1.0m x. Here are some dashboard screenshots:

dashboard_tracking.png
dashboard_tracking.png (151.54 KiB) Viewed 2214 times

dashboard_notTracking.png
dashboard_notTracking.png (151.82 KiB) Viewed 2214 times


All beacons are using v5.63 and everything is using default settings. Any suggestions for improving the tracking distance?

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Re: Losing hedgehog tracking after 0.6m

Postby admin » Tue Jul 11, 2017 4:34 am

sdr wrote:We have 4 stationary beacons mounted horizontally to a plate in a rectangular pattern about 0.3m off the ground. This arrangement is able to track the hedgehog when it is close to the stationary beacons but the tracking drops out at distances greater than 0.6m y or 1.0m x. Here are some dashboard screenshots:

dashboard_tracking.png
dashboard_notTracking.png

All beacons are using v5.63 and everything is using default settings. Any suggestions for improving the tracking distance?



Hello,

I see, at least, 2 potential points to check:

1) In your modem settings you have limitation of distance set to Auto. It means, that the system will choose how long to wait for the the ultrasonic signal to come automatically based on the maximum distances between stationary beacons. Since you have pretty unusual setup - very short distance between stationary beacons and tracking outside of the stationary beacons - most probably, you simply hit the Limitation of distance area. And the system doesn't wait for the ultrasonic signal anymore at all.

What you have to do - to switch to manual mode and choose the distance to track in meters.

2) I see that RSSI is pretty high - -27dBm. Maybe, you simply go too close to the modem, and mobile beacon is overloaded with the radio signal from the modem. Keep modem 1-2m from any beacon

Please, notice, that triangles in trilateration will be very narrow in your setup, and you shall expect quite drastic decrease in precision, when going farther from the stationary beacons.

BR,
Maxim

sdr
Posts: 4
Joined: Mon Jul 10, 2017 10:23 pm

Re: Losing hedgehog tracking after 0.6m

Postby sdr » Tue Jul 11, 2017 6:04 pm

Hi Maxim,

1) I tried setting the max distance to 10m and 100m but neither had any effect on the tracking distance.
2) The RSSI is in the mid-30s when tracking drops out, which is actually worse than when the tracking is working.

I can still see the hedgehog distances in the distance table updating if I continue moving it after the tracking drops out. They increase as I move further away and stay somewhat constant when the hedgehog stops. We had a similar setup (triangular with three beacons) working pretty well with the previous firmware (v5.51) before I upgraded -- has anything changed that might affect this? Should I try downgrading?

smoker77
Posts: 107
Joined: Sat Feb 06, 2016 4:03 pm

Re: Losing hedgehog tracking after 0.6m

Postby smoker77 » Tue Jul 11, 2017 6:52 pm

Hello,
By default the service area for mobile beacons is limited and mobile beacon not positioning far from stationary beacons. The limit is 1.5x of maximum distance between stationary beacons. To expand the service area please follow instructions on the attached screenshot. Also notice that positioning of mobile beacon far from stationary beacons and close to their plane may give increased positioning error because of bad geometry of measurement.
Attachments
service_area_setup.PNG
service_area_setup.PNG (79.25 KiB) Viewed 2190 times

sdr
Posts: 4
Joined: Mon Jul 10, 2017 10:23 pm

Re: Losing hedgehog tracking after 0.6m

Postby sdr » Tue Jul 11, 2017 9:13 pm

Thanks, this fixed my problem!

I set the submap area to a 5m x 5m square and it's working now. We don't plan on tracking any further than 4-5m away and we don't need to be very precise so I think we're good to go. Thanks again.

MarkusLav
Posts: 1
Joined: Wed Jul 26, 2017 1:45 pm

Re: Losing hedgehog tracking after 0.6m

Postby MarkusLav » Thu Aug 03, 2017 10:32 am

Thanks Smoker, that was very helpful. I was having the same problem as sdr and your solution fixed it!


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