Online Cortex Thoughts on Science and Technology

I have just uploaded three videos of a LEGO NXT rover that uses the rocker-bogie suspension system employed by the current Mars rovers.  This design is based heavily on the design presented by Brian Bagnall in his book Maximum Lego NXT: Building Robots with Java Brains

I described the rocker-bogie suspension system in a previous post.  The idea originated with the bogie, which is a set of six wheels on a train designed in such a way to keep all the wheels on a curved track.  The innovation here is to add rockers allowing the wheels to move up and down independently.  This enables the rover to handle extremely rough terrain, and as I demonstrate, climb barriers higher than the wheels themselves.  A more detailed description can be found on BrickVista Tech-Notes.

The first demo was filmed in my brother’s backyard in Wisconsin where he had just put in a fence.  The terrain is relatively rough with bumps and dips with sizes on the order of the diameter of the rover’s wheels.

The second demo was filmed in my office in the Physics Department at the University at Albany.  Here the rover climbs a pile of some of my favorite books.  Several of the book heights are on the order of the diameter of the wheels themselves.  Watch how the rockers allow the wheels to climb independently.

The third demo was filmed in the access road just outside the Physics Department.  A small parking barrier, approximately the height of a curb, is the obstacle to be overcome.  The rover is able to climb the barrier, and the rocker-bogie suspension allows its wheels to hug the barrier as it rolls over.  The rover then heads off towards a small tree… perhaps in search of life. 

We improved on the design by increasing the torque on the tires (decreasing the speed) and by replacing the front drive shafts with a gear system.  Long LEGO axles tend to take a good deal of torsion and store this energy like a spring.  This leads to oscillatory motions in the wheels.  In addition, the coupling was too weak to enable our rover to climb the desired obstacles, and our gear system overcomes this.  Another way we found to overcome the torsion of long drive shafts is to construct a shaft out of small axles joined by axle connectors.

There are more improvements to be made.  One design flaw is that the front wheels are too powerful and sometimes lift the entire front end of the rover without allowing the rockers to rotate.  This is because the back wheels are also progressing a given rate of speed and for the rockers to rotate, these wheels would have to slow down.  A properly-placed differential should solve this problem.

In the meantime, this basic rover design is sufficiently robust for outdoor exploration.

Below are several books of potential interest.

Kevin Knuth
Albany NY

Posted under Exploration, Intelligent Systems, Inventions, Lego, NXT, Research, Robotics

This morning I was surfing the web for LEGO Arm designs to try to come up with ideas for stabilizing the pretty mediocre arm I built last night for our upcoming demonstration at MAXENT 2007.  I came across a blog called the Open Prosthetics Project featuring a piece titled “Articulated Hand: Low Cost Prototyping with LEGO“.  where they described the work of John Bergmann who has prototyped a prosthetic hand using LEGO technic parts.  They even posted building instructions.

The subtitle of the blog is “Prosthetics Shoudn’t Cost an Arm and a Leg”.  I agree, and neither should robotics.  The fact is that LEGO’s prefabricated plastic parts are ideal building blocks.  Why spend $100s of thousands of dollars and several months to develop laboratory prototypes when you can do it for hundreds of dollars and several days.

Its amazing, but real people are doing real things with LEGOs.

Kevin Knuth
Albany NY

Posted under Entrepreneurship, Inventions, Lego, Neuroscience, Research, Robotics, Solutions

I am sometimes a bit behind when it comes to certain aspects of internet technology.  That is the price I pay for focusing on my own research on intelligent instruments and robotics.  I have been noticing that the blog search engine Technorati, keeps track of what I am posting on my blog.  Not only that, it is also integrated into Wordpress so that when I log-in to my blog, I can see who has been linking to me.

So today I made it official.  I went onto Technorati and provided them with some basic information about who I am and what my blog is all about.  As a little reward, I got this new button just here to the upper left, which enables others to mark my blog as one of their Technorati favorites.

Kevin Knuth
Albany NY

Posted under Internet

Later this month, June 26-27, 2007, we will be holding the Data Mining in Aeronautics, Science and Exploration Systems (DMASES) Conference at the Computer History Museum in Mountain View CA.  This meeting is being organized by Ashok Srivastava, Dawn McIntosh, and Bob Beil from NASA Ames Research Center.  I am the Chair of the Science Session, and am very happy with the four speakers that we have arranged: Amy Braverman (NASA JPL), Jeffrey Jewell (NASA JPL), Leslie Foster (SJSU), and Rama Nemani (NASA ARC).

Kevin Knuth
Albany NY

Posted under Research

I received an email from my friend Barney Pell the other day announcing the launch of Powerset in September 2007.  Powerset is developing the next generation search engine, which relies on natural speech processing!  Right now you can sign up to try the Powerset demo before its release!

A video introduction to Powerset can be found on YouTube.  Even more information can be found on Barney Pell’s blog (Powerset Founder and CEO).  Interesting finds include a link to a video of a colloquium talk he gave to the Department of Computer Science and Engineering at the University of Washington on May 1st.  In this interesting talk he discusses the basics of natural language search.

Kevin Knuth
Albany NY

Posted under Computation, Entrepreneurship, Internet, Inventions, Research, Software