CHAPTER 9 ■ ROBOBOAT

• A GPS-controlled autopilot hardware/software system, based on an Arduino platform called ArduPilot

Some Words in Advance

When I was a student at the university (which was quite a long time ago), I was taking a course for control-loop design. One of the tasks was to optimize the control-loop parameters for an assembly that balanced a wooden stick. The stick was mounted on a roller skate, which was fixed on either side to a rope. The rope was connected to a motor that moved the roller skate with the stick on it back and forth. The motor was controlled by an analog PID controller. It worked quite well; the skate oscillated a little bit and held the stick in a perfect upright position. The whole assembly looked very crude, and the wooden stick was indeed a branch from a tree. I asked my professor why they did not make a more perfect assembly with a metal stick instead of a branch, and with a better push-pull assembly. His answer was short:

“If your assembly is mechanically perfect, nobody would believe that the system is balanced by electronics.”

With this in mind, I have designed the RoboBoat. The mechanics are very simple and sometimes crude. But, if you see your catamaran on a lake, following a straight line and returning to the launch point like a boomerang, you'll see how right my professor was.

Parts List for the RoboBoat

Let's first start with the parts list for all the materials that are needed to construct the boat (Table 9-1), the propulsion assembly, and the electronics. I have tried to use materials that are easily available in do-it-yourself stores and model shops.

Table 9-1. RoboBoat Parts List

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