Lego is now selling a product called Mindstorms. This is a great way to get started in robotics - for ~$200 you get a microprocessor, 2 touch sensors, a light sensor, 2 motors, and a whole bunch of Lego bricks and various other pieces. Everything is very modular and you do not have to worry about the electronics. So - it is very easy to prototype ideas and it is ideal as a learning/teaching tool (especially up through 12th grade).
One downside of Mindstorms is that the microprocessor can be connected with only 3 motors and 3 sensors. This significantly limits the size of the project that one can build, unless one can figure out a way to hack the unit to bring out more IO, or somehow integrate 2 microprocessors together. The other downside is the clunky visual-based programming language that runs on a windows box (there is apparently a mac version in the works as well). As an experienced programmer, I found it very limiting. However, it is a good way to get started if one has little or no experience with programming. The upside to this point is that other mechanisms are becoming available for doing programming in a more conventional setting. Their web page talks about some of these options. One of the promising approaches is legOS, which provides a real-time kernel that can run on the RCX and allows one to do development under linux! Another option is the BRICXCC development environment.
A good book for getting started at a bit lower level is Mobile Robots: Inspiration to Implementation by Joseph L. Jones and Anita M. Flynn (A K Peters Ltd). This is in a textbook format that covers sensors, actuators, interfaces, microcontrollers (the MC68HC11) and programming. I have found this to be a very useful book for teaching. The robot bodies described in the book are actually based on Legos, so this represents a possible way to grow beyond the Mindstorms kit (although at that point, it may be easiest to replace the Mindstorms RCX microcontroller with something like a Handyboard - so that additional IO is available).
There is a lot of good information in the Robotics FAQ.
Finally, another quick way to get into doing actuation is to use standard RC servomotors, driven by your home computer. The Robot Store sells a product called "Mini Serial Servo Controller 2", which allows you to drive up to 8 standard RC servomotors using a serial port. These servos contain a small control loop, so your computer just has to tell them which position to move to. The Robot Store also sells many other useful items like small microprocessors and H-bridges. Also - the Jones & Flynn book talks about how to modify RC servomotors for purposes such as driving the wheels of a mobile robot.
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Last modified: Tue Aug 27 16:21:34 2002