CHAPTER 6 ■ ROBOT LINE-FOLLOWINGThe better the surface contrast and the slower the robot’s pace, the steeper the turns the robot can
perform. Feel free to experiment with increasingly difficult arrangements. After all, the worst thing that can
happen is that the robot wanders away.
Many designers fret over line crossings or line splits in the course (see Figure 6-6). It’s possible for some
robots to head between the lines as the brightness averages out. But, the robot circuit presented in this book
isn’t confused by such intersections, and quickly settles into one path choice or the other.
Figure 6-6. A crossing and a split
It’s fun to watch the robot choose between equally split forks in the road. It doesn’t always pick the same
route. In fact, on multiline crossings, I’ve seen the robot take a wide turn and head off in the most remote
direction. Perhaps it’s just bored, but usually a shadow or bad hop explains the decision.
Summarizing Course Conditions
In summary, the Sandwich robot follows a moderately thick, easy-to-see line around an obstacle-free flat floor.
The course should feature gradual turns on a high-contrast surface illuminated evenly by indoor lighting.
Picking the Robot’s Size
It would be cute to build a really tiny robot. Maybe one that fits into the palm of your hand (see Figure 6-7).
Unfortunately, very small robots are difficult to assemble and work on. Small details require steady hands,
patience, and experience. Like a miniature dollhouse, all of the parts on a small robot need to be equally
small. This limits part choices and options.