Sample Robot #2

Robotic Maniacs (See Home Page)

Modified from Sample Robot #1-B design.
Large drive wheels near center axis, between RCX and motor.
Motors behind RCX body drive each wheel via two medium gears (1:1 ratio)
Rear idler wheel (without tire) on center line.
Side facing ball arm, with basket for carrying ball and hooks for grabbing dowel, directly connected to a motor axle.
Light sensor under body, near front, facing down.
Touch sensor at front, facing forward, with a wide push bar attached. (not used yet).
Feelers with bar extending from front for pushing balls off top of ramp.
Beam framework surrounding RCX and each motor.
Rotation sensor not included, but could be added under RCX body, behind axles.

Good traction on smooth or carpet surfaces.
Fast motion on flat surfaces.
Works forward and backwards.
Excellent turning ability (can turn in place).
Likely to have ok climbing ability (not yet tested -- use fresh batteries)
Wheel drive is simple and reliable (single pair of gears).
Ball arm is simple and reliable (direct drive, no gears or belts).
Same arm useable for pulling a bar (mission 1) and dropping/throwing balls (mission 2).
Sideways facing arm does not require a turn to pull bar (mission 1) or drop balls in container (mission 2).
Light sensor can detect black floor line, to determine when to stop, turn, etc. Positioned at front so the robot sees line sooner in its travel.
Touch sensor available if needed.
Spare sensor port available.
Small compact design.
Beam framework provides rigidity and strength.
Touch sensor bar partially reinforced.
Light sensor mount partially reinforced.
Ball arm attachment to motor held in place by adjacent brick.
Ball arm prevented from turning off robot (green button) with connector as restraining pin.
Ball arm prevented from swinging too far by limit bar.

Positioning the robot to close enough to the structures for mission 1 and mission 2 might be difficult.
If the arm misses pulling the dowel, its location and orientation are different that if it pulls the dowel, making it difficult to program a reliable return to base in both cases.
Using timing rather than rotation sensor makes the distance travelled dependent on surface, motor load, battery condition, etc.
The touch sensor is not currently used, so it is just taking up space and weight.
The touch sensor bar is not solidly attached, and could fall off if bumped hard.

November 23, 1999