The ‘jewel in the crown’ of an engineering degree at Wollongong is the final year project. Each student works individually with an academic staff member on a ‘real world’ project which involves research, the development of theory to describe a system, and the building and operation of experimental equipment to see if the theory accurately describes the actual results. For example, one mechatronic’s project this year involved the design of a computer controlled mechanism to illustrate the successful automatic control of the classic ‘broom balancing’ problem. Imagine balancing a broom vertically on the palm of your hand using your hand-eye coordination to move your hand in the right directions. With some practice, this is not too hard. But consider how hard it would be with a second broom balanced on top of the first one, as shown in the figure. Is this even theoretically possible? Now do it with your eyes shut! (This is similar to trying to stand up straight balancing on one foot with your eyes shut, as your body is mechanically roughly equivalent to two straight links rotating about the hips.)
This technically challenging problem was solved by one of our thesis students this year, Phil Commins. He used an electrically driven ‘cart’ as the hand, and a high speed computer as the brain, and sensors (developed by physicists) to provide the computer with very accurate and rapid information about the positions of the brooms. The computer uses this information, combined with a detailed knowledge (this knowledge consists of mathematical equations derived by Phil) of how the system will react to the cart’s movement to decide the directions and speeds to move the cart to achieve stable balancing of the two ‘brooms’. It makes these decisions about one thousand times per second. By the end of the project Phil was able to demonstrate, after of course several mishaps, that an entirely autonomous computer controlled system was able to do this.
Intriguingly it turns out that theoretically at least, it is possible to balance an infinite number of brooms on top of each other with a single computer controlled cart. Perhaps next year another lucky student will be given this job for his or her 2007 thesis!
