Creeper needs attack mode

[perigalacticon]

Hey fellow Trossenites,

I built a Minecraft Creeper prop (see my profile) for Halloween a couple of years ago with the intention of fully robotizing it, am I'm planning for this year now.

I'm looking for recommendations on a mobile platform that can move Curt (the Creeper) around and scare small children when they get too close on Halloween night. Or any other night. Or day. I managed to get Curt moving with 2 cheap-o plastic tracked chassis controlled with a sketch running on an Arduino mega; I got him to turn his head back and forth and travel in a square on my hardwood floor. it also has a dozen or so high powered LEDs inside for exploding and such and a pretty loud speaker also for exploding and what ever Curt might try to say.

I see there are a lot of awesome robots, and I found ROS, and I think I want to learn it, I got pretty deep into Arduino and think I can make the leap (I'm not a professional programmer).

I don't have a huge budget, but I'm looking for the most high level system I can get because what I want to do is make use of it for fun, not do serious research with it.

At a minimum, I want Curt to wander around my flat concrete driveway at idle, and maybe out onto the sidewalk and back. This sounds to me like it needs SLAM. When encountering fellow Minecraftians I'd like Curt to interact with them in various ways. Such as exploding. or Not, maybe if they hit him with a sword or arrow. I think I will be comfortable with programming some interactivity but ROS and the navigation will be all new. I'd also like to be able to control Curt by remote at any time.

At a 2nd level, I'd like Curt to chase people wherever they go, across the yard and onto the road and wherever they may go, hide behind objects, just like in the game.

I estimate Curt weighs around 25lb with 12V Lipo battery. A lot of the chassis I've seen handle a lot more than that, and are also beyond my current budget. I'd like to keep it around $1000 for now. The base of Curt is 24"x18" and he's about 4ft tall.

Is there any hope for me to obtain these goals this year? What would you suggest oh robotic gurus and geniuses?


Sincerely,
the Perigalacticon

[jwatte]

You don't need SLAM, because you can already build a map ahead of time.

You might want to use something like a couple of ultrasonic sensors to measure distances to edges, and perhaps a magnetometer / IMU to figure out orientation, which will let you triangulate against the known walls to know where you're at.

Even simpler would be to have something like an IR beacon blinking at a known frequency (say, 100 Hz so it's not confused with 60 Hz) and detect it and its strength to have a "home bearing" and don't get too far from that.

If you have a little more cash, you can look at something like the POSZYX boards/transmitters to get a real location.

[Tommy_T]

At a minimum, I want Curt to wander around my flat concrete driveway at idle, and maybe out onto the sidewalk and back. This sounds to me like it needs SLAM.

perigalacticon, as this is a temporary application I could see laying down masking tape over the path, then
setup the Minecraft Creeper prop as a two wheel drive line follower(other two wheels as casters), I could
see using different colored masking tape to trigger a Minecraft Creeper prop action.

example: if tape color is blue and ultrasonic sensor is less then(some value) the Minecraft Creeper prop turns on red
light and stops.