Robotics coz I'm lazy

sensors

2008-09-11T17:54:00.002-05:00

I have chosen the front sensor to be an ultrasonic sensor for the time being. The initial thought is that ultrasonic will not have as many false positives as an IR outside during the day. See attached for the simple test and results of the sensor. This can detect a pencil at 2 feet during my testing.

back at it

2008-09-10T20:56:00.001-05:00

So I finally got around to taking a picture of the 2 H-bridges used to power the algorithmic test bed motors. They are just simple H-Bridges powered by two 9 Volt DC batteries until I get a better battery for the whole shebang. You can find a schematic for it here.
See below for some pictures....

Also, below is a movie I made of the tank chassis rolling down a hill (driveway) to test if the friction of the axles needs to be modified.

some what scale testers

2008-06-08T21:09:00.000-05:00

While the chassis is undergoing construction, I figured I can mock up some quick scale models to test the various components and algorithms for navigation.
I was given an RC car to play with and with some quick disassembly it looks like I can use it to test the navigation algorithms. See below for a quick disassembly of the car.

Fully assembled. With the top off.

With the motor and electronic cover removed.

The finished product disassembled to a usable chassis system. Now to work on the electronics to bypass the radio and battery control systems. See the next post.

chassis design

2008-05-29T20:58:00.000-05:00

my initial design was to use a tank chassis from an idea I got looking at RC tank combat websites. These guys build 1/6th scale RC tanks of military tanks which made it to production and then shoot paintballs through the turrents at each other's tank. Neat idea I think.

See the picture for the chassis with wheels, belts and the motors in place.

robotic platform

2008-05-27T22:23:00.000-05:00

Now for the platform I've chosen the BS2 chip from Parallax since it is a good starter chip and language and was recommended by a book which is right up my alley (123 Robotics Experiments Evil Genius)

If you get this book, I highly recommend buying the parts from Hobby Engineering as they have the majority of the experiments covered in bundle packs.

Having said all that, I am most of the way through the book and only have a few experiments left. I have begun to work on some of the more advanced stuff, like GPS integration and H-bridge motor controllers (also from Parallax).

starting up

2008-05-27T22:14:00.001-05:00

this is about my epic journey to build a robotic lawnmower. I am starting with a several phased plan as I have limited time and resources to devote to the project. Initially the project aims to do the following:

Run self contained (no starting and/or stopping it)
Mow my back yard
Include object avoidance
Have a safety trigger for a dead stop
Scale to run in the front yard.