Larry V3

Larry did a lot of schooling last night.  He's at version 3.0 now.  He can now play a note, counts to 3 and realizes that zero is a number.  Many problems solved.  Larry is getting smarter and hung up less.  In this pic, he's looking a little peaked.  He's been through lots of testing and two battery packs today.

Notice the low sensor.  Larry won't approach something he can't climb over now.  I haven't tried overhead environments; but, I'll test that sometime later.  Also notice that Larry has a third servo that drives his eyes.  He constantly scans back and forth looking for things he might run into.  At this point, Larry will only get hung up on objects that he approaches at a very shallow angle.

Larry had to learn how to count today.  Up until now, Larry could get trapped in a place where he needed to make a left turn to get out.  So now, every 4th right turn in a row, Larry will make a left turn instead.  When he makes a left turn, the count resets.  He can still get boxed in; but, he's also not making 90 degree turns, so he tends to find his way out after the first couple times around.

Next steps for Larry...

*  Larry simply needs help on his undercarriage.  He should be proud of himself and not have droopy drawers.

*  Larry is going to learn how to pick a direction of travel instead of counting turns.  This will be done by choosing the most open path and a speed appropriate for that path - tighter quarters, slower speed.

Introducing Larry

Larry is my first robot.  I made him with the Lego EV3 kit (review later).

I started working on one of the 5 robots that are suggested by Lego; but, bailed after I got the base done.  I couldn't see any reason to make a tractor robot with  a spinny looking propeller on the front.  By the time I had the tracks together, I was very familiar with the Lego framework and decided I wanted to start playing with the ultrasonic sensor and the programming.

For those firefighters in this blogsphere, Larry is programmed to do a left handed search.  I could put a camera on top of Larry and you would see my house from the perspective of a cat or small dog.  The whole point was to learn how to program the brick to do things.

Larry is in pretty good shape right now; but, there are some problems that need to be overcome in Larry V2, such as:

*  The ultrasonic sensor has a narrow field of vision.  Larry will hit an object not directly in front of Larry; but, in line with one of the tracks.  When that track stops and the other keeps moving, Larry moves toward the object and gets hung up.

*  The ultrasonic sensor will look over an obstacle that is only a couple inches high.  Larry will hit this object with gusto.

*  Larry is not programmed to stop.  He will search until he dies, or gets hung up.  Since Larry also doesn't know what he's looking for, he keeps searching.

*  Larry needs stiffer britches.  His tracks kinda cant inward.

*  Larry has no concept of gravity requiring a surface to move on or injury.  If started on a table, Larry will charge off the end of the table, fully expecting to survive the fall.

Other than that, Larry will do the left handed search pretty well.  V2 will fix the first 2 problems by moving the ultrasonic sensor down, midway between the top and the bottom and if possible, include a turret that allows Larry to look left and right.  I will also adjust the programming so that Larry looks left occasionally to make sure there isn't an open room that needs to be searched prior to continuing forward.