Ping2 sonar gives incorrect data at close range

Blue Robotics Products Ping Sonar Devices
1

Hello dear friends. We purchased the “Ping2 Sonar Altimeter and Echosounder” device. When our vehicle is very close to the wall of the pool, the received data is extremely large, and the reliability is high. How can we prevent this?

2

Hi @berkant -
By “reliability” do you mean the confidence estimate? This may be due to multi-path reflections in your pool, and is somewhat unavoidable if so… In open-water environments, it should not occur!

3

Thanks for answer. We will try algorithmic solutions.

4

Hey @berkant we are trying to accomplish a similar project of mapping a swimming pool using the Ping2 for obstacle avoidance.
Were you able to come up with any algorithms to solve the issue, or have any suggestions of where we should start?

5

Hi @berkant and @ben1219925 -
Setting the maximum range the Ping2 is searching within to detect the bottom may help reduce the risk of multipath interference!

6

Hey all,

We’ve been having some issues with this in shallow reef environments across a range of ping2 units for bluerov and blueboats. The issue presents as a depth reading thats very high (eg 90 metres) when its in the order of 2 to 3m. It does this with very low confidence, and will periodically switch between these bogus values and the correct ones, with no clear pattern i can discern. Sometimes it does it at all the times, sometimes barely so when running missions back to back.

Is there any way we might be able to correct for this in post? I note looking at the pingview output that the surface is easy to see in the return but for some reason it calibrates to a really deep reflection.

7

Hi @Vincent -
The SimplePing Survey extension will record the confidence value, so you can simply filter out results with low confidence…

As for your issue, beyond setting maximum range manually, there may not be much you can do without modifying the Ping firmware - this will soon be publicly released / possible to do.

Decreasing your survey speed in the meantime may improve the situation?

8

Hey Tony,

I thought as much. Slowing down survey speed isnt really feasible.

Wil tet manually setting the limit amd see if it helps