M.A., I remember this link for a stereo webcam:
http://code.google.com/p/sentience/wiki/MinoruWebcam
Reasonable baselines for indoors are 6 - 10 cm; wide-angle lenses also help.
Cheers --Kurt
On 10/28/2010 11:21 AM, Anh Nguyen wrote:
> Hi Kurt,
>
> Thanks for the helpful answers. Look like cheap stereo vision is not an
> easy option, especially with my limited hardware skill.
>
> Can you extrapolate a bit more on augmenting VSLAM with odometry or
> IMUs. I have the odometry reading for my robot. How do I configure VSLAM
> to work with one camera and combine odometry / IMU with VSLAM (what
> would be a simple algorithm for that)?
>
> From what I read, I also assume that IMU would work indoor, is that
> correct?
>
> Also, if I go with stereo camera,is there any requirement regarding the
> baseline, resolution, frame rate... for making it work with existing
> VSLAM stack?
>
> Best,
>
> -M.A
>
>
> On Thu, Oct 28, 2010 at 1:08 AM, Kurt Konolige
> <konolige@willowgarage.com <mailto:konolige@willowgarage.com>> wrote:
>
> M.A. -
>
> VSLAM currently works only with stereo cameras. VSLAM with monocular
> cameras is much less robust, unless it is augmented with other sensors
> such as odometry or IMUs.
>
> Using two webcams to make a stereo pair is difficult. You have to:
>
> 1. Make sure they're rigidly mounted
> 2. Synchronize them
>
> Synchronization is difficult for standard webcams. At the moment I
> don't think there are any cheap off-the-shelf stereo cams. Here's one
> reference for a do-it-yourself:
>
> http://sszymczy.rootnode.net/index.php?menu=projects
>
> It would be nice to do some kind of VSLAM on the Create using odometry
> to help, but that would take some work.
>
> Cheers --Kurt
>
> On 10/27/2010 9:46 PM, Anh Nguyen wrote:
> > Hi everyone,
> >
> > I have a few questions about VSLAM. I am new to robotics and most
> of its
> > terminologies so I would appreciate any references that may
> explain the
> > background needed to understand your answer :)
> >
> > - Can I use ROS VLSAM stack using only one camera (a webcam on my
> > netbook to be more specific).
> > - If so how do I configure VSLAM to get this to work?
> > - If not, can I add another external webcam and use them as a stereo
> > video system or do I have to purchase some commercial stereo
> camera? If
> > I have to purchase a commercial system, is there any good one for <
> > $400 range?
> >
> > Has anyone tried to get VSLAM to work with iRobot Create? I spent the
> > last few weeks creating a reduced version of the PrairieDog stack
> that
> > work without the laser range finder and the stargazer, and mapped my
> > office using the robot's bumper sensor, only to realize that I cannot
> > rely solely on the robot's encoders for accurate localization.
> >
> > Thanks a lot,
> >
> > -M.A
> >
> >
> >
> > _______________________________________________
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> > https://code.ros.org/mailman/listinfo/ros-users
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