Technology and Source Code

Each bug is a small autonomous robot 2.5"W x 2.5"L x 2.8"H. The robots were designed to be flexible, serving as a general framework for collective robotic experimentation.

The essential components are:
1- PIC16F876A microcontroller for processing logic
1- L293D H-bridge for motor control
2- GM10 geared pager motors for mobility
1- TGS2620 smell sensor for trail following experiments
1-2 CDS photocells for sensing others
3- lever switches for collision detection
3- LEDs for attracting others and debugging
1- LM2937 5V regulator

There are several different programs I have written for testing the bots exploring various types of group behavior. So far I have experimented with trail following, light and smell tracking, and flocking. Of these programs the most interesting behavior has arisen from a simple light-track and follow program. In this situation each robot has a super bright white LED mounted on its head which is left constantly on. They are programmed with simple rules:
1. seek light
2. if a light source is found (another bot) attempt to move with the light source
3. if the light source is lost, briefly retrace your steps and try to find it again
4. if it cannot be found go back to step 1

Starting with the robots distributed in a 10' rink these rules lead to coupling, clustering and eventual flocking behavior. The robots appear variously playful, flirtatious, desperate, or rejected, and go into periods where they seem to be dancing with one another. Of all the programs so far I am most pleased with this one and the C source code is available here.

Future...

I now have ten small robots for experimenting with collective behavior and emergent situations. Future plans include working more with smell and trail following, experimenting with artificial evolution, neural networks, and developing more complex rule sets. I see the robots as a great tool for teaching and learning about emergence and group dynamics. As I flesh out the project I would like to bring the robots into increasing contact with the public. I can imagine bringing them into classrooms as well as installing them in public spaces. Ideally they will be portable and robust enough to be packed into a small suitcase and released just about anywhere to encounter the world at will.
Next hardware revision will port all components to surface mount packages cutting the size of the total robot approximately in half. It may utilize the 6mm GM15 planetary geared pager motors. It will also include an in-circuit serial programming connector so different software experiments can be tested quickly and easily.

If you have any questions or would like more information please email me.