[ros-users] Single Laser dependency

[Eric Perko]

Prasad,

On Wed, Oct 6, 2010 at 12:57 PM, Prasad Dixit <abhimohpra at gmail.com> wrote:

>
> Thank you all for those quick responses.
>
> 1. I can receive encoder information through odometry messages. My worry is
> now related to the range i have with URG-04. Is there any work around by
> which i can overcome the issues of large area?
>

Buy a longer range laser scanner? What sort of environment will the robot be
operating in? You mentioned a museum earlier - if that is the case, you may
not be able to sense very far anyways if the museum becomes crowded even if
you had 30 meters of range. You could try doing some sort of localization
with, for example, ceiling lights or other fiducials; basing localization on
info on the ceiling can be a good idea in a crowded environment as generally
the view of the ceiling from the robot will be unobstructed.


> 2. I will surely look into the package of laser tools though... but it is
> intended to be used without any odometry and in our system we can have
> encoder information.
> 3. Ivan: which model of angular rate sensor (Gyro) you are preferring?
> So like, as suggested by you Gyro + Laser Range + odometry will quite
> improve our Robot localization even i dont have IMU sensor.
>

To add another datapoint to whatever Ivan is using, we currently use Analog
Devices ADXRS150 gyros, but it looks like those have been obsoleted by
Analog Devices. Really, what you want to look for is a maximum sensing rate
greater than your expected maximum turning rate so you don't saturate the
gyro, an interface your microcontroller or computer can talk to, and either
automatic biasing or enough outputs to allow you to do the biasing on the
fly. The two biggest things to watch for with the gyros are their saturation
values and the bias (bias being what the gyro actually reports when you
aren't turning; this value can drift relative to temperature).

- Eric


>
> - Prasad
>
> --
> View this message in context:
> http://ros-users.122217.n3.nabble.com/Single-Laser-dependency-tp1640828p1643841.html
> Sent from the ROS-Users mailing list archive at Nabble.com.
> _______________________________________________
> 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/20101006/7712a1e7/attachment-0003.html>