Autonomous Robot
Builder: Jan Malasek
For my second robot, I built an autonomous robot that could move around and avoid obstacles and back up from ledges. I had much more information about where to get components, and I even got some sample Motorola H-bridges for bidirectional control of both motors. I also learned about wire-wrapping, so the electronics are assembled with a mixture of point-to-point soldering and wire-wrap.
The chassis is a 15" circle cut from delrin, and the motors were from my first surplus store: Ax Man in Minnesota. I think the wheels were baby stroller wheels, which I epoxied onto the gearbox output shaft. I used the same ball caster as on the robot line tracker for the third contact point.
The sensors consisted of bumper switches and IR reflectance sensors facing out and down. The downward-facing sensors were based on 40 kHz IR remote control sensors. The bumper on the front was from the lawn care section of the hardware store.
For this robot, I had also moved on to some programming. I initially made a card that interfaced to a PC parallel port and ran the chassis with a long tether. I later found out about the BASIC Stamp from Parallax and moved to that for untethered operation. I networked three Stamp circuits (there was no Stamp 2 back then) to get enough I/O lines. The control panel switches and the displays allowed a user to set parameters, such as how long to back up or turn in response to various sensor inputs, without requiring a PC to reprogram the Stamps.
Autonomous Robot
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