Problem: people aren’t good at drawing accurate graphs on white boards, to solve this problem we aimed to build a robot which could calculate and draw graphs of mathematical functions more accurately than humans. Our original success criteria were as follows: robot is able to draw on the board horizontally and vertically, robot is able to calculate linear functions given by the user, stretch goals: able to graph more complicated functions, easy to use UI.
Development: our robot went through many iterations this is mostly due to the unexpected difficulty of making a machine travel across a single rail without stopping or falling off. We eventually succeeded in making the robot move horizontally, we did this by introducing unused motors at the back as a counterweight. After this we moved on to the vertical movement, the idea was to have a marker attached to string which could move up and down with the help of a motor. To make the pen actually draw on the board we used masking tape to attach Lego to it, this would make it have a more stable face to rest against the board with and allow it to apply more pressure. After doing this we found that the counterweights we added to stabilize the robot were detrimental to the final robot. After building all the mechanical parts of the robot we had very short time to program it so after a rushed coding job we had succeeded in drawing a diagonal line across the board.
Reflection: The final prototype does satisfy the basic criteria but can only do the same graph every time. The two stretch goals could not be achieved as they required more complicated programming than we had time for. Final thoughts: we learned to plan for much more failure than expected.
