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Figure 3.2 The balance of the forces acting on a Segway and its rider when
stationary, accelerating, cruising, and decelerating. Reprinted with permission
from Brian Hughes.
3.1.4
Stray Pooch
Stray Pooch is a senior design project that was built by students from Wichita
State University in 2011. This project’s goal, to be an interactive dog toy, is
similar to Puppy Pal. Their robot was built using a large hamster ball. The
mechanical system consists of two motors connected to a gearbox. Shafts are
connected to the motors and the sides of the ball. As the motors rotate, the sides
of the ball rotate and drive the ball forward. A similar system was used in Puppy
Pal’s mechanical system. Unlike Stray Pooch, the shafts were instead attached
to wheels that were controlled by their own motors inside of the gearbox instead
of being attached to the ball itself. The framework inside of the ball was made out
of wood and aluminum. Combined with the electronics, the frame was too heavy
to work properly; the center of the frame dragged along the bottom of the ball,
slowing down the robot. This showed that weight had to be watched closely when
constructing the mechanical portion of Puppy Pal. In their follow-up experiments,
the Wichita group rebuilt the frame with aluminum. Aluminum is much lighter than
wood, so the mechanical system worked more efficiently when the change was
made.
This group used an Arduino to control Stray Pooch. Although there are many
tutorials available for Arduino applications, the group’s lack of experience made
the coding part of the project very difficult. The Puppy Pal group members
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