Newsgroups: comp.robotics
Path: brunix!uunet!spool.mu.edu!umn.edu!msc.edu!apctrc!hawkings!natos114!zjoc01
From: zjoc01@hou.amoco.com (Jack Coats)
Subject: Re: Bugdozer questions
Message-ID: <1993Jul26.074035.24369@amoco.com>
Sender: news@amoco.com
Reply-To: zjoc01@hou.amoco.com
Organization: Amoco
References: <22tngj$ctq@scratchy.reed.edu>
Date: Mon, 26 Jul 1993 07:40:35 CDT
Lines: 57

Check out some of the previous postings from the AAAI competition.  What you
want to do sounds similar to their 'coffee pot retrieval' event.

In article ctq@scratchy.reed.edu, reeder@reed.edu (P. Douglas Reeder) writes:
>>Bugdozer Questions
>>
>>I am building a small (20 cm), robot whose goal is to find
>>and return small objects to a beacon.  It is differentially
>>steered with two large wheels and a smaller caster, and
>>controlled by an HC11 EVB.  It will discriminate between
>>objects, returning some and ignoring others; also, it will
>>only return those small enough to move.  The test objects
>>will be ping-pong balls and tennis balls, though any
>>moveable object is fair game.  I will monitor motor current
>>to detect stalls, and thus immovable objects (like walls),
>>along with bump sensors and near-IR proximity detectors.
>>
>>1) I am contemplating having the robot push the objects with
>>a flexible bulldozer-blade/bump-sensor.  When pushing an
>>object, the blade would be concave, to help keep the object
>>in front of the robot.  When not pushing, a servo would push
>>the center of the blade out, so it would be convex and less
>>likely to hang up on objects and walls.  Does this sound
>>feasible?  Would you suggest some alternate setup for
>>pushing?  Should I just have a rigid concave blade and make
>>sure the IR proximity sensors give complete coverage?
>>
>>2) The difference between "good" objects and "bad" objects
>>must be obvious to a human, and cannot be something active
>>like a beacon.  I am looking at using a phototransistor and
>>visible LED to discriminate between objects, returning only
>>dark ones (walls are usually light colored).  Would checking
>>for some other quality be easier and more reliable?  Should
>>I look for red objects, with a red filter over the sensor?
>>
>>3) What combination and geometry of "good" object sensor,
>>bump sensors, and proximity sensors should I mount on the
>>blade?
>>
>>4) Can I use the IR proximity recievers to also detect an IR
>>beacon at the same 40kHz carrier without screwing up
>>proximity detection?
>>
>>5) Has anybody done this before?
>>
>>--
>>Doug Reeder                              Internet: reeder@reed.edu
>>Div, Grad & Curl                         USENET:   ...!tektronix!reed!reeder
>>programming & derivative work 
>>I am actively seeking scientific programming contracts.



---
-- 
                         Ideas: mine              LawyerSpeak: theirs

