This is my second robot. It's going to run off of an Arduino Diecimila. It will have 3 servos, used for movement. I currently have 2 of them up and running. My plan is to take a 3rd, and suspend weight (about a pound of polymorph or lead) from it. I will use it to keep the base paralell with the ground.
It will drive in a wierd way: the 2 servos I already have will rotate, trying to turn the platform. As the platform is weighed down by the 3rd servo and its load, the platform will stay steady, as the ball turns forward or backward around it. To turn, the 3rd servo tilts the weight towards either drive servo, while the ball is spinning forward or backward. If you don't get this, think about the Earth. The north and south poles are where the F/B servos are. The equator is the line where the bottom of the ball touches the floor. As the ball tilts to one 'pole', it will rotate the platform inside. Then when the weight evens out again, the ball goes back on the equator, but with the orientation different, it will be facing a new direction.
Its only sensor so far will be a long distance Sharp IR, as I have heard they can see through plastic.
Update: August 13, 2009
My Arduino Diecimila came! I'm working full tilt to ge this 'bot done now. I can order new parts, such as my 3rd servo, and the handful of sensors...
I now have all I need to finish it. its only a matter of time...
possibly… those are valid points. i’ll just need to sense them early then. (my servos are weak, so it’ll go slow) which has better range, a sharp IR or a FritsLDR? does anyone know of any instructions on a homemade Sharp IR?
Arduino Issue You may need to press the reset button after clicking "Upload". I think a certain batch of Arduinos has a wrong resistor or something like that. Hope it helps.
Popular Science has a “Future of…” series. Last night was “Future of Security” and it included an autonomous rolling ball robot. Very cool application of the type of bot you are trying to build.
I can’t find any decent links to it yet.I found this article from much earlier on the bot. Here is another one that includes a video.The company making the bot is calling it “Rotundus”.
The bot was originally developed for exploration on other planets, so it is completely sealed and able to go through/over sand, water, ice, snow, etc.
It has two gyro-stabilized cameras on domed pods on either side of it. The rolling surface was black and looked like rubber with nubs for traction. It can be remote controlled or use GPS waypoints to navigate autonomously.
Physical science. After the laws of physics change. Apparently, the ball acts as a ‘fresnel lens’, making readings from IR sensors seem closer then they really are. Once I get some better hardware, and another handful of servos, it will have an extending PING))) from the sides, to take readings there.
Have you thought of trying a Have you thought of trying a different type of sensor, maybe ultrasonic, to see if they get through the "lens" of the ball better than IR?
