Newsgroups: comp.robotics
Path: brunix!uunet!utcsri!helios.physics.utoronto.ca!alchemy.chem.utoronto.ca!pdavies
From: pdavies@alchemy.chem.utoronto.ca (Paul Davies)
Subject: Re: Seeking high-resolution ultrasound system
Message-ID: <1992Nov10.230411.11815@alchemy.chem.utoronto.ca>
Organization: University of Toronto Chemistry Department
References: <92315.0022523034871@QUCDN.QueensU.CA> <1992Nov10.192123.14608@meaddata.com>
Date: Tue, 10 Nov 1992 23:04:11 GMT
Lines: 29

>3034871@QUCDN.QueensU.CA (Ralph Siemsen) writes:
>: We're looking for some ultrasonic (or otherwise) detector to measure
>: distances of 5-15 cm to an accuracy of +- 0.5cm or better.
>: 
>: The intended application is to measure the angle (by triangulation)
>: of a monopod robot relative to the ground. We have considered
>: accelerometers, but the bouncing action of the robot makes them
>: innefective. Commercial angle sensors are expensive ($1500) and we
>: really only care about a small range of angles (20 degrees), rather
>: than the full 180 degrees that most commercial units offer.
>: 
>: So it would be quite easy to measure the distance to the ground from
>: a platform atop the robot. All we need is a nice sensor.

I remember in undergrad some guys built a broom handle balancing robot.
It only had 1 degree of freedom.  They used a pot and calculated the
angle from that.  Since it was analog it was very fast.  It worked
pretty good except the tires slipped on the floor (i think they later
tried to use a chain and gear wheels).


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