[ros-users] how to use sonar to navigation?

Bence Magyar mw.mzperx at gmail.com
Wed Nov 10 11:54:36 UTC 2010


Hi there,

my answer is not strictly about ROS but about sonar sensors.

If you're working with a sonar sensor instead of a laser you have to do
something about the wrong data you get from the sensor.
I can find what type of sonar sensor your Pioneer 3 is using but what sensor
we are trying to use at the university is quite messy.

This is quite a good description of sonar sensors in global:
http://www.omron.com.au/technical_guide/ultrasonic_sensor/index.asp

With no intention of advertising:
http://www.robotshop.com/eu/ultrasonic-range-finders.html
just scroll through this page and look at the diagrams near the pictures.
They show how wide the sensors can actually "see".
If you want to emulate a laser scanner with a sonar sensor you'll might have
some problems.

I attached a picture describing the so-called pheriferical vision (or side
vision). We did this experiment with a simple box and got the result I
drawed in paint. The grey box is unseen but when I turned it a bit (black
box) the sonar sensor thought  it is right in front of him.
We're experimenting with different statistical filters to somehow get rid of
this side vision effect. Side vision effect depends on the objects relative
angle in the pheriferical zone ("seen surface" of objects and sound waves
reflected from them) .

You need a sonar sensor close to "tunnel vision" to avoid getting silly
data.

I hope my answer wasn't too messy :)

Regars,
Bence


2010/11/10 Jolin Jia <pplin86 at gmail.com>

> Hi,
>
> My robot is Pioneer 3, but I have not the laser sensor, for that Hokuyo and
> SICK sensors are way out of reach for us. So I want to use sonar to make
> SLAM and then make navigation. And I want to find an existed package to
> achieve our goal, but it seems that it almost pretty much requires the usage
> of a laser for SLAM and navigation. So how can I begin my work to use sonar
> to achieve SLAM and navigation. Is there any examples to help me?
>
> By the way, I have studyed the amcl package several times, But I still
> don't know where Publisher the topic "scan" or "base_scan", that's to say,
> where the laser data comes from?
> Any help will be appreciated! Thanks in advanced!
> jolin
>
> _______________________________________________
> ros-users mailing list
> ros-users at code.ros.org
> https://code.ros.org/mailman/listinfo/ros-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ros.org/pipermail/ros-users/attachments/20101110/27916789/attachment-0003.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: sonar.png
Type: image/png
Size: 4592 bytes
Desc: not available
URL: <http://lists.ros.org/pipermail/ros-users/attachments/20101110/27916789/attachment-0005.png>


More information about the ros-users mailing list