Discussion

Despite the seemingly simplistic needs of the robot, the design and the parts require a lot more attention. First the tank had been placed in the front to offset the weight provided by the roller; however, this proved to be dangerous as water would be traveling above the circuitry. Therefore, all of the circuitry was placed in the front on two tiers: one for the breadboards and one for the microcontroller. The tank was also connected to a solid instead of a flexible pipe that rotates on the same center point as the roller. Unfortunately, the roller attachment had to be slightly off-center in order to line up the roller with the robot. This disrupted the symmetry between the two turns, requiring different adjustments.

        ?Another challenge was getting the robot to turn precisely 180 degrees and 90 degrees and go straight afterwards. Not only were the servo motors that were being used temperamental and refused to go straight in the first place, but also the roller attachment ultimately dragged and forced the robot to drift to the side of the roller. Hence an S-turn was applied to the program to straighten the roller by dragging it further into a turn [fig.3]. However, several design flaws prevented constant results from occurring; one was the rotating back wheel, which created unpredictable turns; another was the offset roller position, which created uneven drags on the two sides.

        ?In the future the several design flaws discussed previously will need to be fixed in order to refine the turning. Also, the servo motors must be replaced with dc motors because more power may be needed to pull the roller along with the liquid. A centered roller attachment along with the back corners cut to prevent the roller from getting caught on the corners is necessary.

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Fig.3 S-turn for 180 degrees