Subject:
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Re: Robot Positioning using Beacons
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Wed, 1 May 2002 14:24:31 GMT
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Viewed:
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7473 times
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The problem with IR is that it tends to get everywhere, reflecting
off of surfaces etc, so it's hard to triangulate.
May I suggest a related but different approach.
Make your beacons out of hybrid IR/sonar transmitters. The beacons
will periodically send a coded signal on the IR (e.g., "beacon 1")
as well as a simultaneous sonar ping.
The robot can then receive the IR pulse and the sonar ping, and
measure the time lag between them to determine distance from the
beacon. (The IR pulse will travel more or less instantaneously,
while the sonar is ~1 ft per millisec.)
Put a couple of these in your room and you can triangulate.
fred
On Wednesday, May 1, 2002, at 01:34 AM, Chris Steiger wrote:
> I am beginning to design a handyboard robot that, for starters,
> can navigate
> around a room. The idea is that it will travel to objects whose
> coordinates
> within the room are predetermined and interact with them.
>
> I plan to do this by triangulating the robots position within the
> room. I
> would like to build three simple IR beacons consisting of a simple IR
> emitting LED that can be adjusted to pulse at different rates.
> These would
> be mounted in opposite corners of the room and each will be assigned a
> different pulse rate. The robot will have three IR receivers to
> detect the
> beacons. Each IR receiver will have it's own Sonic Rangefinder to
> find the
> distance to the beacon. This would give the robot x, y, z
> coordinates in
> the room. Any room with dimensions that exceed the maximum range
> to the
> range finders or IR receivers will have multiple beacons, but the
> robot will
> always have three "sensor arrays." The unique pulse rates for
> each beacon
> will identify them, and there will be databases of coordinate
> systems for
> each possible combination of beacons being used (always the three
> closest).
> Each sensor array will rotate on a stationary point on the robot
> to locate
> the beacons.
>
> I have a few questions:
>
> 1. First, are there any flaws in my idea?
>
> 2. What is the cheapest and simplest way to build the IR
> beacons so
> that I can assign them different pulse rates?
>
> 3. Will the sensor arrays also need to angle up and down as
> the robot
> moves closer and further from the beacons, or can the beacons remain in
> their field of vision while they stay stationary?
>
> 4. What would be the best IR transmitters, IR receivers, and sonic
> rangefinders for the job?
>
> I appreciate any help anyone can give. I'm new to robotics and my
> education
> has not yet caught up with my ambitions.
>
> Thanks,
>
> Chris Steiger
>
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Message has 1 Reply:
 | | Re: Robot Positioning using Beacons
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| That sounds good, but what do I use to drive each beacon, (e.g. send out the coded IR signal and sonar ping). Using a full blown microcontroller like the handyboard for each one would be incredibly expensive and wasteful. I only need a controller (...) (23 years ago, 1-May-02, to lugnet.robotics.handyboard)
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Message is in Reply To:
| | Robot Positioning using Beacons
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| I am beginning to design a handyboard robot that, for starters, can navigate around a room. The idea is that it will travel to objects whose coordinates within the room are predetermined and interact with them. I plan to do this by triangulating the (...) (23 years ago, 1-May-02, to lugnet.robotics.handyboard)
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