design and construction of mobile surveillance robot

ALTERNATIVE DESIGNSSession 4CThere were three different designs considered for use: ahanging weight design [1], a “hamster ball” drivendesign[2], and a dual-tread design[3]. The capabilities andrequirements were considered along with several othercriteria when generating these design possibilities.The hanging weight design consisted of a central shaftwith a carriage hanging from the shaft as displayed in Figure2. The carriage would have the ability to rotate around theshaft which would allow for movement forward andbackwards. The carriage would also have a small weightinside which would shift side to side to allow the sphere totilt from side to side while moving forward or backward, andin so doing provide a turning capability.FIGURE 3HAMSTER BALL DRIVEN DESIGNThe dual-tread design would contain two wheels thathave the ability to turn in opposite directions to allow for azero turn radius. The design would not be perfectlyspherical, but would still retain the benefits of a sphericaldesign. A model of the dual-tread design is displayed inFigure 4.FIGURE 2HANGING WEIGHT DESIGNThe “hamster ball” design would operate similar to howa hamster is able to move around in a plastic ball. A robotwould be contained within a clear plastic sphere withcontrollable wheel(s) at the bottom that roll along the insideof the sphere. The wheel(s) would be able to rotate so thatthe sphere could travel in any direction. It would alsocontain stabilization arms that would keep the robotcentered, the wheel(s) in contact with the sphere, and wouldalso protect the components inside the robot if the spherewere to suffer a sudden impact. A sketch for the “hamsterball” design is displayed in Figure 3.FIGURE 4DUAL-TREAD DESIGNAll three of these designs were evaluated using adecision matrix that included several design criteriaimportant to the project. The results can be seen in Table 1.Pittsburgh, PA March 26 - 27, 2010ASEE North Central Sectional Conference4C-2