Scorpion - ECE 4413 (Intro to Controls)

The objective of the class contest was to stop the instructor's remote control vehicle. His vehicle was a 22 inch diameter aluminum mixing bowl, with a six inch diameter, five inch tall PVC pipe and cap on top. On the PVC pipe was 16 yellow LED beacons, and 16 IR LED beacons blinking at 40 kHz. On top of the pipe cap was a one inch diameter red button, which stuck up from the top by one-half inch. The object of the contest was to design an autonomous vehicle that could track the instructor's vehicle and push the red button on top. The red button, when pressed, turned off a bunch of red LEDs on top of the cap. When these LEDs were turned off, that signalled a capture.

My robot was built using an aluminum frame, and an aluminum arm that was solenoid driven. Two "wings" made of un-fluxed brazing rod were bent and attached to the sides of the robot. This was to keep the target vehicle from "skitting" away when we were close enough to swat at it.

A couple points:

  1. Our robot was faster than expected. (The direct-coupled gearhead motors were so fast, we ran at 25% duty cycle for top speed.)
  2. Our IR reciever was quite sensitive. (When a road sign reflected the IR signal from the target, we went straight for the road sign!)
  3. Out steering algorithm worked. (We hit the road sign dead on.)
  4. Aluminum channel stock doesn't take straight on hits well. (One hit to the road sign, and we spent 15 minutes repairing the "paddle".)
  5. Sometimes a simple, passive design works better. (Most of the designs were passive button pushers, including the first place team. Adding active components such as the solenoids driving the paddle hurt our chances. The "proximity detector" was our weakest link.)
  6. We had a lot of kinetic energy with our weight at around 38 pounds. In the "chasing" picture below, that large dent in the target vehicle was from our robot the first time we colided with it. At the end of the contest, there were 4 large dents, all from Scorpion, as well as gouges and large scratches in the paint. Someone forgot to tell us that this wasn't a combat contest!
All in all, it was a very exciting and interesting concept. We placed 2nd, with a much simpler design taking 1st place. If you're a professor into robotics, e-mail me and I'll get you in touch with the professor that ran this.