This project began when one of my students approached me at the beginning of summer 2016 with the desire to create a robot that could roam around our department, talk to students, take pictures to post to a Twitter account, and
ultimately provide a scalable robotic platform for students
to build upon. Because this robot could be subjected to
some wear-and-tear as a result of its frequent interaction
with students and faculty, I immediately thought of using a
power wheelchair as its base.
Relatively inexpensive power chairs are easy to find on
eBay (if you are willing to go pick them up), and my
student and I found one for $130 that was within driving
distance: a Pride Jet 3, with a Penny+Giles Pride control
module (see Figure 1). Once we purchased new batteries
(for another $120), we thought we were in business, but
the conversion from chair to robot was a bit more
challenging than we first anticipated.
Opening the Module and
Fomulating a Game Plan
We started by taking a look under the hood of the
control module, which — again — amazingly houses all of
the electronics for power, motor driving, and electric brake
control. The photo in Figure 2 shows an inside view of the
control module. It may be difficult to tell, but the module is
tightly packed; there is hardly any unused space inside.
The top of the box holds the bargraph power indicator,
the power button, and the joystick, along with several PCBs
(printed circuit boards) which serve to interface these
components to the rest of the module via a ribbon cable
and a bundle of two small wires.
The dense packing of the electronics in the module was
overwhelming at first. However, since the joystick is the
most direct way of controlling the motion of the chair, that
seemed like the most logical place to begin our
By Darby Hewitt
Figure 1. The Pride Jet 3 power chair I found on eBay. Figure 2. Inside view of the Penny+Giles Pride control module
that came with my used power chair.
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