Saturday, September 18, 2010

This week's top five...

Here are five web sites / artcles / documents that I've come across in the last week or so and found very interesting...
  • Build IT: Underwater LEGO Robotics - I think this site might contain the most impressive and practical set of curriculum resources relating to a particular challenge that I've ever seen.
  • Robotics Design Studio - Another great site, including resources and a project museum that showcases some fabulous robotics creations.
  • Math and LEGO - This is document, by Tufts undergrad Sarah Tavares, is a collection of ideas for teaching mathematics concepts using LEGO materials. Seeing this collection has helped me to accept that I should do something similar, focusing on the concepts in my year 11/12 Mathematics course back home.
  • Can Math Help in LEGO Robotics Competitions? - As far as I can tell, this is a unique piece of research. This morning I had a good chat with the article's author, Eli Silk, about this and his related work. I'm looking forward to learning more about what he has been doing.
  • LEGO Boardroom Table - Nothing to do with my study here at Tufts, but I thought it was fun and somewhat inspirational.

Friday, September 17, 2010

The little sloth that could

After starting full time at the Tufts' CEEO on Sept 1, I spent the first few days summarising the 60 or so articles relating to robotics education that I read in preparation for my fellowship. I was making good progress, except that for every five articles I re-read and summarised, I found another article that I needed to add to my reading pile. )-:

I also spent far too much time setting up a Mac mini only to watch it die just two days later. I then learnt how to retrieve files from a non-booting Mac, before finally accepting that I'd be better off using my own PC laptop anyway.

Last week, classes started and I've hardly stopped to breath since then. I've been attending four classes, two with an engineering focus and two with an education focus. Here's a brief description of the two engineering courses...

Chris Rogers' ME-84: Introduction to Robotics
ME-84 is a 3rd year Engineering course that provides an introduction to robotics, drawing on computer science, electrical engineering, and mechanical engineering. I'm doing this course not only to develop my own understanding of engineering, but also to see what engineering concepts and skills I can use in the development of a pre-tertiary robotics/engineering course back home. Because all the students undertaking the course have a solid grounding in engineering, this course goes way beyond anything I've ever taught before. E.g. It's week 2, and we're using the NXT to investigate different types of control (on-off, proportional, integral, derivative).

In the first lesson, we had a quick challenge to make a robot that moves, but without using wheels as wheels. This is what happened...

Assignments in this course consist of a weekly design challenge. The first assisngment was to create a sumo robot using any kind of remote control. The results were presented in class on Tuesday of this week where our robots battled each other. In my team, we decided to make a robot that would have a low centre of mass, could spin on the spot (as a defensive strategy), use a flipper to lift other robots off the ground (reducing their traction) and be remote controlled by another NXT over bluetooth. I was also keen to limit our solution (for the vehicle at least) to the parts from a single NXT Edu kit, but this put our robot at a huge disadvantage. There were some heavy duty robots in the competition!!

Ethan Danahy's EN-10: Simple Robotics
The other engineering course I'm doing is EN-10. This is a 1st year Engineering course that provides a much easier introduction to robotics and LabVIEW than ME-84 and is much closer to courses that I've taught in the past. I'm taking this class to help with my understanding of basic engineering principles, and for extra practise at design challenges - I suspect that many of the challenges in this course are ones that I've given students, but never done myself.

As in ME-84, the assignments consist of weekly design challenges. For our first assignment, we were challenged to create a robotic animal that moves in some way. I wanted to create something that could climb along a rope, so decided to create a sloth. I started with just a motor and a couple of beams tethered to a NXT held below the motor and tried to come up with something that could move along a rope without falling off. On the way I learned a lot that I didn't know, or hadn't realised, about linkages and balance. Once I had it working for a single motor, I then added an NXT and an extra set of legs to help support the weight of the NXT.

From 2010_09 EN10 Robotic Animal

From there, I added a head and, with more than a little help from home, I added some fur and ended up with my version of the sloth...

There were lots of great designs from the rest of the class, including a hopping frog, a couple of alligators, and Jumbo (the elephant that is Tuft's official mascot). You can see photos of some of them here.

Next week's challenges are to create a piece of robotic playground equipment (EN-10) and a musical instrument on which a recognisable tune can be played (ME-84). It's back to the drawing board...

Thursday, September 9, 2010

And so it begins...

I started "full time" at the Center last week and figure it's about time that I started posting to this blog regularly, otherwise I never will. For those who don't know, a little over twelve months ago I won a Hardie Fellowship, enabling me to undertake research and study at the Tufts University's Centre for Engineering Education and Outreach (CEEO). A few months ago, I posted some early thoughts about my fellowship, and now it's time to continue that story...

Two weeks ago, I came into the Center for a Biomimetics workshop with members of the Harvard Microrobotics Lab. These guys have been working on some awesome robotics projects, including some amazing bio-inspired projects such as sub-200mg micro air vehicles. I was surprised to learn that they had never played with LEGO robotics. The workshop started with an introductory challenge, for the Harvard team’s benefit, to create a robot that moves. We were working in pairs. Pairs that had prior experience with the NXT were given an additional challenge. In my pair, we worked on making a weight shifting, walking robot. We based our approach on an idea that used an RCX motor that I recalled from the 2nd edition of Eric Wang’s Engineering with LEGO bricks. Because the NXT motors are bigger than RCX motors, we needed to scale up our robot, and eventually ran out of time to complete the challenge. This is, however, one that I would like to come back to at some stage.

Following the first challenge, we had a discussion and brainstorming session about different movement/propulsion systems in nature. We came up with a list that included walking, hopping, jumping, climbing. The Harvard team were very knowledgeable about biological systems.

The second challenge was to choose one of the movements and replicate with the NXT. In my pair, we worked on a swinging robot. We ended up trying to simulate the movement of a child on a swing, using the motors as the legs. This lead to some lively discussion about the important of legs v the position of the body, and whether or not swinging legs at the right time puts energy into the motion. We calculated the period of the swing based on its length, and used this as a guide for determining how frequently to move the legs, but ended up having to adjust this to keep it in sync. More research (and in particular, a trip to a set of swings!) is required.

The workshop concluded with my first game of ultimate frisbee (I was glad that I wasn’t the only newcomer to the game) and pizza. It was a great introduction to being at the Center, and I left looking forward to coming back...