Robotic Eye-Hand Coordination using RoboRealm
from United States  [214 posts]
7 years

I just finished up some work on using RoboRealm to guide my robot as it reaches toward a target object.  The ultimate goal is for the robot to be able to pick up the object from a random location or take it from someone's hands.  For now, I simply wanted to work out the coordinate transformations from visual space to arm space to get the two hands to point in the right direction as the target is moved about.  The following video shows the results so far:


I don't have a full write-up yet on how I did this but it basically just uses 3-d coordinate transformations from the head angles and distance to the target (as measured by sonar and IR sensors mounted near the camera lens) to a frame of reference attached to each shoulder joint.  The Dynamixel AX-12 servos are nice for this application since they can be queried for their current position info.  The distance to the balloon as measured by the sonar and IR sensors is a little hit and miss and I think I'd get better performance using stereo vision instead.


mbahr from United States  [23 posts] 7 years
Good grief that is impressive!

I see your rovio videos also.  Have you shared that code anyplace (I'm just learning...)

from United States  [214 posts] 7 years
Hi Mike,

Thanks for the nice comment.  As for code, I am in the middle of porting all my old C# stuff into Python so I can use the ROS framework (Robot Operating System by Willow Garage).  So I don't have anything clean enough to share at the moment.  (Although I did recently release two open source Python libraries, one for controlling Dynamixel servos and the other for controlling the Serializer microcontroller.  See http://www.pirobot.org/code)

If you're relatively new to all this, I would highly recommend going through the RoboRealm tutorials (see the link above) if you haven't already.  Also, you might glance at some of my blog posts at http://www.pirobot.org where I have written some tutorials on object tracking and coordinate transformations.  (BTW, one  of the reasons I am migrating to ROS is that all the frame transformations are done for you, even for arms with many degrees of freedom.)

Good luck,
mbahr from United States  [23 posts] 7 years

Prior to trying roborealm I was playing with the MS Robotics stuff, and was put off by the use of C#.  It's been something like 20 years since I've done any C, and than it was just poking around.  Not sure I want to go down that path again.  But perhaps I will end up doing that.  

I stumbled on ROS last year.  That is a bit more than I want to chew on right now.  But wow is it impressive.  I heard they are selling their robot now, also, but that it is well out of my price range.  

I previously stumbled onto your blogs and have gobbled up the tutorials, as well as the roborealm tutorials.  Now that I have roborealm working (solved an interference with AVG) I can jump in and test the waters.  Roborealm seems extremely powerful.  It's nice to be playing in this age where there are so many low cost choices!!!

I'll follow your progress with ROS...


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