Tank's Page

Fellow BEAMers, meet...

...my latest walking / exploring machine!

Early pics of Tank --- Tank's Tactiles

Introduction:

This is Tank, a 5-motor walker (including its head), that seeks out a bright light and goes towards it. This robot was inspired by many things, like the Scoutwalker 2.2, Mark Tilden's Unibug 2.0, Strider and many other bugs combined. Some says, it looks like a grasshopper or a praying mantis. But I came up with this figure, that looks like a little bit of an army tank (with legs). So, that's why I named this creature, "Tank".

Tank has 5 tactile sensors for obstacle avoidance. It's eyes are 2 phototransistors and was angled at about 30 degrees. Tank also uses 5 micro servos for the legs and the head, that makes it much smaller than the Scoutwalker II. One of its tactile sensors are used as a "panic switch" (which I call it), which makes it back-up for a few seconds (it backs-up and turn sometimes) when it is stuck in a critical condition, like in a leg of a chair or a table.

The whole circuit was carefully designed and made, using a universal board with solder-ringed holes. All the wirings and jumpers are underneath the board, so the top is perfectly clean and neat looking. You'll notice that, it has 2 boards for the body. One is for mounting the servos (legs), batteries, charging socket, LED charging indicator, power switch, tactile sensor and head mounting. The other board is (obviously) the circuit board.

By the way, I would like to thank Mr. Ray Diaz for helping me out, when I needed some 2nd opinions for "Tank". Thanks dude! ;-)

Features & Behaviors:

Phototropic Bicore Head (with left and right limit switches).
Scoutwalker II's circuitry (with modifications).
Has a total of 7 sensors - 2 phototransistors (eyes), 2 tactiles (left & right) and 3 "panic switches" (front, left & right shoulders).
Moves forward, backward, turn left & right and sometimes backing-up & turn.
Seek/explore first for a few seconds (light-seeking) then walks.
Has a charging socket.
1 LED charging indicator.
1 power switch.
Uses only 3.6 volts Ni-Cad batteries (3 "AAA"s with 500mA each).
Uses centering-springs for the legs.
Has left and right bright-red-LED signal lights, to indicate a triggered tactile.
Infrared sensors (not included - for future development), that can see objects or persons and goes towards it. I detached this sensors because it eats too much power, using a 3.6 volts only. Maybe a separate battery will do.

Additional notes:

The "panic switch" sensor makes this bot back-up for a few seconds, just to escape in a tight and critical conditon (trapped), especially when it is stuck in a leg of a chair or table. Eventhough the head is still seeking (left or right), when one of the panic switches is triggered, the seeking behavior will stop at once and the bot starts to walk backwards (reverse). These panic switches are located on the front head and its left and right shoulders.