Innovative student solutions to a robotics design exercise

The paper focusses on the development of a hands-on project-based evaluation procedure for a senior level university course in robotics. In essence, the evaluation procedure involved dividing the class into small teams. Then a universal task was given to all the teams, which required the design and construction of a robot to complete. The object of the task was to develop an autonomous machine that could find and retrieve a specific ball (1" dia.) from the bottom of a water filled container. Three balls (one aluminum, one steel and one plexiglas) were initially randomly placed into a 16" deep plastic container (trash can). Then a die was thrown to randomly select which ball was to be retrieved. Once the robot had been set for retrieval of the selected ball, it was placed on top of the container and switched on. No further human intervention was then permitted. A set of rules were issued to explicitly define the task and permit judgments of success or failure to be made. Having successfully applied this concept to the Fall 1995 Robotic Systems class at USF, a number of common solutions were observed amongst the eight robots created. Ball retrieval tended to be achieved using either a suction pump, a bottom searching scoop, or a paddle/elevator arrangement. Having retrieved all three balls, a sorting system was employed, usually involving a cantilever scheme that separated the balls by weight. A second more ingenious technique was to separate the balls based on how far they bounced when dropped