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|Target Environment||Locomotion Method|
|Sensors / Input Devices||Actuators / Output Devices|
tactile sensor switches
|modified Futaba S3003 servos|
|Control Method||Power Source|
|CPU Type||Operating System|
|Time to build||Cost to build|
|URL for more information|
|TIKE is a small 2-wheeled robot utilizing differential
steering for navigation. Using 2 Radio Shack project
box covers, I glued 2 modified futaba S3003 servos for
continuous rotation onto a metal cover and screwed a 5
inch screw through both plates and bolted them off. I
fashioned a circuit board deck by cutting a 5 1/2" by
4 1/2" rectangle of plexiglass and mounting it on the
remaining 5 inch screw clearance. Adding a grid of
velcro strips on the deck to ease the robots construction
aided its modularity.
TIKE's brain is a Parallax Basic STAMP I with a single 8 I/O pin port. 4 lines are required for driving TIKE's high power H-bridge motor control circuit(MOSFET). 2 of the remaining 4 pins are utilized by tactile sensor switches. This leaves only 2 pins for other sensors/ actuators. I'm working on implementing photo-electric (cadmium sulfide) sensors and a condensor microphone so that TIKE will exihibit a roach-like behavior: wandering around aimlessly until a loud noise scares him into finding a dark place to hide, and only returns to wandering after a considerable time of silence.
TIKE cost me 30$ for both servos, 40$ for the high power H-bridge, $65 for the BASIC STAMP I and the carrier board and about 10$ in plastic and plexi-glass plates and screws and bolts. A total $145. Though I'm sure if were to manufacture all the circuitry myself and substitute an MC68HC11A controller the cost would be around 60$. This is my first wheeled robot, I thought it turned out great considering I took only 2 nights to build it.
The only problems I encountered with TIKE were power management and tire traction. I initially let him roll on the plastic Futaba servo horns which caused him to slip severely on my tiled floor. I tried putting a thin layer of glue around the edge, which worked, until it started getting worn away and stringy. I got the idea to glue on a KINEX plastic wheel that has a rubber edge after seeing my brother play with it. The traction is excellent.