kwatters's blog

So, I saw on hack-a-day that there was going to be a meetup at the Artist Asylum here in Boston.  I wasn't even aware of any maker spaces around here, so I just had to go check it out.  Awesome times, lots of cool projects, including.. yes..  a hover board... 

Ok, So I realize that I'm editing and updating this blog in reverse.. but so be it.  Anyway, here's another little update on the progress with these bevel gear / robot arm joint project.  It moves!  It knows where it moves!  

Well, as we open the gateways to blender from MRL, it seemed like a pretty obvious leap to start trying to render point cloud data from the kinect via OpenNI in blender.  I had the kinect write out to a text file all the x,y,z points.  In a small python script in blender, I loaded that text file and rendered small circles for each point.  

Just came across this robot...  It's a bit more agile than the InMoov .  

Wow. this is a big topic.. I really just want to start the conversation about a few things in MRL.  An open source DSP software library TarsosDSP was identified as a nice library to help implement these DSP like functions.  The library says that it is for audio processing, but lets consider that audio processing is just analog processing.  Arduino analog inputs are definitely analog and should be able to be pumped into any self respecting DSP library.

New OpenCV filter  "SimpleBlobDetector" has been added.  It will watch a video stream and count up the number of blobs that it sees.  

There is no blob tracking, right now, it just tracks all points of interest so long as the new point of interest is more than 10 pixels away from an existing one.  

In the image below, I drew some blobs on a sheet of paper and held it up in front of the camera..  look at that, there are 5 blobs! 

So,  I was able to get 2 cameras (OpenCV) working at the same time as having 1 Kinect (OpenNI) running.

Interestingly enough, comparing the camera images to the kinect image, it seems the kinect has the image reversed on the x axis...

I recently saw some posts in the InMoov forum talking about how the supply lines are very important to being able to power the servos properly.  My initial reaction was that the resistance of the wires going to the servo motors should be negligable.  I mean, after all , it's wire.. it's copper.. it's a conductor.  When we think about circuits we always consider that the wires don't have any resistance at all.  They're ideal conductors, if you will.

My new years resolution is to really get a good understanding of industrial robot arm control with the hopes to come up with some dynamic control to keep robots balanced and borg that into MRL.

I recently picked up a robot arm kit from OWI.  It's a 5 degree of freedom robotic arm.  It took about 2.5 hours to assemble.    

Based on http://www.petercorke.com/Robotics_Toolbox.html

I've been working through getting a kinematic model for the InMoov, recently, I stumbled across a python library based on the matlab robotics toolkit.  It uses NumPy for much of the heavy lifting math operations.  

So far I've been able to create a very small script to compute forward kinematcis of a set of links using this python robotics toolkit