Robotic Arm

This past fall I took a robotics class as part of my masters in Mechanical Engineering, and for the final project I developed a control algorithm for this robotic arm.  This was a very interesting project, and it was the first time I’ve used Matlab to control the NXT.  I used some software that had been developed by Linus Atorf, Alexander Behrens, Achim Knepper, Til Aach at RWTH Aachen University to interface between Matlab and the NXT.  This toolkit was very impressive and made the whole project alot easier.  The robot itself was not the focus of the class.

The build was just a simple linear joint, topped with two rotational joints.  However by using the control logic I was able to impliment code that would draw on the paper.  This might sound like a simple feat, however keeping all three motors in sync so that the pen would always be on the paper as it moved in a linear fashion was acutlay quite involved.  I was able to use the feedback sensors in the NXT motors to impliment a PID control law, that was undoubtly way overkill for this small project.

Alpha Rex a Dancing

{youtube}ikbaDv6aNc4{/youtube}Here's a movie of Alpha Rex dancing to the music. This is the final stage from the included instructions. Once you start the program, Alpha waits for you to push the button on his hand. Once you do he starts swaying back and forth, and then when he hears you singing (or the radio playing as in this case) he starts to move his arms and turn his head! It's actually pretty neat, although not useful in the slightest.