Thanks Abe, I am currently looking at a monocular visual odometry algorithm: http://www.hessmer.org/blog/2010/08/17/monocular-visual-odometry/ I will probably port it to C and integrate with ROS. Best, -M.A On Wed, Nov 3, 2010 at 12:16 AM, Abe Bachrach wrote: > Since they are not synchronized, it will probably be equivalent to just > connecting 2 standard webcams. (probably won't work) > > For ~$400 you can get 2 pt-grey firefly MV cameras, and synchronizing them > shouldn't be that hard... > > you can either: > 1) Use a PIC or other digital signal source to trigger both cameras using > their external trigger capability > or > 2) connect the GPIO pin on one of the cameras to the external-trigger pin > on BOTH. (this only requires a jumper "cable between" the two cameras) > > -=Abe > > On Mon, Nov 1, 2010 at 12:46 AM, Kurt Konolige wrote: > >> Anh, I'm not sure if it will work, since I haven't tried it. >> >> Cheers --Kurt >> >> On Thu, Oct 28, 2010 at 1:03 PM, Anh Nguyen >> wrote: >> > Thanks again Kurt, >> > Do you know if this Minoru setup will work with vslam? I remember >> reading >> > somewhere on ROS wiki that the timestamp from the two camera should be >> > exactly the same, and it is said on the Minoru project website that >> those >> > two webcams are not synchronized. >> > Best, >> > -M.A >> > >> > >> > On Thu, Oct 28, 2010 at 2:07 PM, Kurt Konolige < >> konolige@willowgarage.com> >> > wrote: >> >> >> >> 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 >> >>> > 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 >> >>> > >> >>> > >> >>> > >> >>> > _______________________________________________ >> >>> > ros-users mailing list >> >>> > ros-users@code.ros.org >> >>> > https://code.ros.org/mailman/listinfo/ros-users >> >>> _______________________________________________ >> >>> ros-users mailing list >> >>> ros-users@code.ros.org >> >>> https://code.ros.org/mailman/listinfo/ros-users >> >>> >> >>> >> >>> >> >>> >> >>> _______________________________________________ >> >>> ros-users mailing list >> >>> ros-users@code.ros.org >> >>> https://code.ros.org/mailman/listinfo/ros-users >> > >> > >> >> >> ------------------------------------------------------------------------------ >> Nokia and AT&T present the 2010 Calling All Innovators-North America >> contest >> Create new apps & games for the Nokia N8 for consumers in U.S. and Canada >> $10 million total in prizes - $4M cash, 500 devices, nearly $6M in >> marketing >> Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store >> http://p.sf.net/sfu/nokia-dev2dev >> _______________________________________________ >> ros-users mailing list >> ros-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/ros-users >> >> _______________________________________________ >> ros-users mailing list >> ros-users@code.ros.org >> https://code.ros.org/mailman/listinfo/ros-users >> > >