High precision radio positioning system for metrology

Hello everybody,

I'm trying to create a high precision positioning system using a
triangulation method similar to GPS but on a local level. I think
that by calculaing the distance between a receiver and several
(atleast 4) transmiters I can precisely know where de receiver is in
the room.

I hope that a simple phase comarison whould be enough to calculate
the distance between rx and the tx's.

The problem is that I have know idea what sort of wave i should
use: advantages and disadvantages of low/high frequencies. I'm afraid
that I might have problems with multipth effects and electromagnetique
noise created by other electrical devices in the room. I'm also
worried about where exactly the transmission and emission points are
on the antennas since I want highly accurate results.

If anyone has an idea or suggestion I would highly appreciate any
help.

 

Got a major project on your hands there, Gov. Like trying to re-envent the
mouse-trap. You must start at the absolute basics and determine exactly what
your requirements are, and then determine what means will be most effecient
and accurate to produce usable data. You may find the GPS may be less
expensive unless you definately want to engineer something. Suggest
searching the local libraries for good engineering manuals and go fo it.

 

I'm wondering, does it have to be rf? And are you using fixed receivers
or fixed transmitters? A "beacon" that gives out pulses of ultrasonic
sound in sync with a pulse from an infrared led would allow simple time
measurement circuits to be used.

The Nintendo Powerglove ('80s vintage) used an ultrasonic transmitter on
the back of the glove, and a wired link for the sync pulse. The
receivers were 3 transducers mounted to a fixed framework that provided
known distances between the receivers.

Ultrasonic and laser tape measures have pretty good accuracy, and
repeatability. You might try and see if you can interface into some to
provide the range measurement system.

Good Luck!

R Allen

 

Dude, you're in over your head. "highly accurate results"?!? Gee,
how many kilometers/centimeters/micrometers resolution is that?
Sorry, I'm ranting. I have plenty of ideas for you but without specs
and/or application it's hard to make an intelligent suggestion.

MM