Unidrive Robot

This was a project that I worked on in Grade 12 with Jake Bian in Mr. C. Csanits’ (pronounced CHON-ich) grade 12 technology class. The class was project based, with the goal of building a robot that could navigate through a maze and extinguish a candle, the layout of the maze was known, the location of the candle was not. Due to the (rather regrettable) fact that I joined the class late (about a week or so in, I missed out on some of the fun…) Jake had already come up with the basic idea: build a robot that could accurately navigate the maze without involving guesswork, he figured (and I agreed entirely) that if the bot had a single wheel in the centre it would be able to make perfect 90° turns each and every time. (Unfortunately what we did not consider was that this would also make it extremely difficult for the robot to drive in a straight line, it had a tendency to follow a wide arc, but more on that later.) Together we finalized the idea and prepared the proposal (see attachments), Mr. Csanits approved it and we got started. We set about building the robot with relatively good success, until we started trying to test it, which was when we discovered that the single wheel drive mechanism does not lend itself to easily tracking straight… (it did however make perfect turns every single time). Despite our best efforts to correct this deficiency it continued to persist.

The basic design of the robot was a plastic platform with a servo motor mounted vertically which rotated the armature containing the motor and wheel assembly. On top of the platform was an arm which held a damp sponge which would be used to extinguish the candle. Mounted to the bottom and surrounding the motor/wheel armature was a stabilizing unit with four feet to keep the robot upright (the friction between these and the floor/table/maze was the root of the problem with tracking straight). The battery pack and control boards were mounted on the sides.