Path: utzoo!utgpu!news-server.csri.toronto.edu!dgp.toronto.edu!mccool
Newsgroups: comp.robotics
From: mccool@dgp.toronto.edu (Michael McCool)
Subject: Re: Small Hovering Hobby Robots
Message-ID: <1991Jun23.095642.872@jarvis.csri.toronto.edu>
References: <00949D78.A594B600@vms.csd.mu.edu> <25523@well.sf.ca.us> <1991Jun20.155520.12703@sagpd1>
Date: 23 Jun 91 13:56:42 GMT
Lines: 35

I've been following this line for a while, and thought I would put in my
two cent's worth of ridiculous suggestions.

Would it be possible to combine the gyroscope and the lifting blade?
My idea: make the lifter a *ring* that rotates around the *outside* of the 
robot; possibly make the whole robot T-shaped with the batteries at the 
bottom of the T for weight balancing.  The combination of gyroscopic effect
and low center of balance should keep the whole thing stable, and using
the blade doubling as a gyroscope will save weight.  To avoid counter-
rotation, you would actually need two blades rotating in opposite
directions.  If you could control the speeds of these independently
you would have a quick way to rotate the entire robot.
The rings would need to have different numbers of blades to avoid 
"beating" with one another and making a lot of noise.  For safety, you
would have to either cast the blades out of rubber or encase them in a
shield.  

For forward motion, just have some way of shifting the center of gravity 
off-center, which will tilt the robot forward (actually, you'd have to 
deal with the gyro effect, of course... have fun).  So, you don't need
a thruster.  If you had the weight-shifting under computer control you
could probably do dynamic balancing and not need an ungainly T shape.
You are going to need some pretty sophisticated navigation anyways for 
a powered hovering vehicle.  The robot would end up looking like a flying
saucer.   

I tend to like this because it leaves you a lot of protected space in the
middle of the beast to mount your electronics, and a way to suspend things
(like cameras and arms) from the center of the robot.

By the way, I thought of this when I was 15 and it just came back to me.
Don't flame me if it's mechanically impossible; I'm a computer engineer,
not a mechanical :-)

Michael McCool.