Let's Make Robots!

Robot-gatherer design ideas

I have signed up for Robot Challenge in the Puck Collector contest (here are the rules) . The problem is I have not built anything yet... and the competition is this Saturday (26th of March).

Here is a quick overview of the rules. There are two robots on a white playing field. The robots start out from a colored "base" (either red or blue) and must collect pucks(also red or blue) of the same color which are randomly placed on the field and bring them to their starting base (red pucks to the red base if the robot starts on red). The pucks are 4cm in diameter and 1.7cm thick.

I have a general idea of how the robot will work, but I have not decided how to actually manipulate the pucks themselves so I am asking you for ideas.

Most of the robots I have seen simply push the pucks around but the playing field is usually made from several plates and may have cracks and gaps on which the pucks or the robot might snag, so I don't really like this idea.

In another approach, the robot would somehow load the pucks and separate them into two bins, based on color, and dump the correct bin into it's home base.

So what I'm actually looking for is a robust way of lifting the pucks and placing them in one of two bins.

Another restriction is that I have only a limited amount of actuators for this and absolutely no time to order anything. Basically, I have some low gear ratio motors (pololu micrometal 10:1 and 30:1, 12 mini servos with ~3kg*cm of torque, one 8kg*cm servo, a continuous rotation servo and a junk pile).

I am planning to use an Android phone with a 5 megapixel camera as the main brain of the robot, with an arduino or two carying out the comands and reading auxiliary sensors, but I am willing to go with a simpler setup (such as led based color detection).

 

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This looks like the Maxwell's Deamons challenge I did a few years ago. That challenge was to gather the proper color cubes and drop them in your base, the winner being the robot that had the most cubes by the end of the game. We used Lego bots at the time, but you can build using whatever you like. The most successful robot had a funnel in the front, with rotating belts on the funel sides to guide the cubes inside the robot. There, a light sensor would decide what color they are and swing them to the left or right bin. The cubes were never lifted, they were dragged inside the robot where ever it would go. By the end of the game time, the robot would head to the base and lift the side walls so the wrong color cubes would be left outside of the base and the good cubes would be left inside the base. We got angry at the time because the robot was hoarding the other guy's cubes, preventing it from scorring.

Good luck!

Hi Antonio,

I'm thinking that the robot could have a scoop in front of it (perhaps having a servo raise and lower it) and then you could have an arm with a rotating wheel that will be lowered on to a puck in front of the scoop with the wheel rotating so that when the wheel touches the puck, the puck will be moved on to the scoop - maybe it should be more than one wheel and perhaps they should sit close to each other to work like a conveyor belt. When you need to unload the puck the wheels could rotate in the other direction and push the puck out of the scoop. The scoop could have some color recognition in it - perhaps a simple LED + LDR combination.

I hope that made some sense :-).

Good luck with the robot!

My first thought is that maybe you can use a servo to actuate the center of a suction cup. This would allow you to pick up or release a puck fairly easily assuming they are light with a smooth surface. Other wise you might need to resort to blue tack or chewing gum to pick up the pucks.

A vacuum pump and a balloon full of coffee grounds would be perfect but you say you do not have time to order anything.

I never thought about using bubble gum, I need to try it out. Thanks!