Sunday, April 26, 2009

W.I.E.R. by Christopher M. Pempsell

WIER is a full function automated robotic dog. The robot features several sensors for navigation and
collision advoidance. These sensors include ultrasonic infared and contact presure sensors in case
the robot was to walk into a wall it would automatically shut off so it would not damage it self
even though it is constructed from 16 gauge steel so the wall would probably be damaged far before
the robot. For movement the robot uses 4 geared down 12 volt electric servo motors in a cylindrical
housing. These motors are 1/8 horse power peak each and are surplus industrial motors. This supplies
enough power to move the 38 pound robot. Other motors include a motor to operate the tail which is a
simple hand held cd player motor and there is also a hobby motor in the neck and jaw to supply a
swivel and in the jaw compression (.253 lbs.) The robot operates on a set of two oopaq
microcomputers which gives the robot an adjustable program. No robotic dog would be complete without
a bark so I hacked a tape recorder recorded my real dog barking (his name is teddy)and then put that
in the tape recorder and programmed in a random number generator to allow the dog to bark randemly.
For a power source I used two 9.6 volt cellphone batteries to give a total voltage of 19.2 volts of
power. Considering all of WIER's motors are amplified/resisted to 12 volts I put a resister board
with a pair of fuses just in case connecting the robots sensors motors and computers. The robot only
has 12 minutes of battery life when on full walk mode but I am trying to extend that. During the
construction of WIER which by the way stands for Walking Intelligent Electric Robot I encountered
several problems. Some of these include how to make the legs all move in the proper direction at the
right time thiss took me almost a month to iron out. The method that I used to solve this incase any
of you are interested in building a similar robot all I did is recorded a movie of my real dog
walking and then broke that down and measure the intervals and l!
engths. The other major problem that I encountered was keeping the robotic dog walking straight and
not falling down. so instead of equaly balancing the power on both the left and right sides which
are two motors each I increased power to the left side to balance out the walk and to prevent falls
I put strings that I just got at the hardware store (the people know me by name there I run back and
forth so much)and put them between the mounting screws and the chasis holding on the motors. Finally
if anyone out there knows of any materials to create solid state spring loaded rear legs email me
because I can not get just the right bounce on the back legs do to the straight stock metal I used
to construct them. Overall this robot took me three months to construct and I am still tinkering on
and off with the program. I don't have a website yet devoted to my robotics and theres a few so I am
currently building a website. A picture of my robot I have emailed to you entitled WIER should soon
follow my submit form.

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