Fixed-wing Ultrasonic Altimeter

[UAVeez]

Does anyone know of a good Fixed-wing Ultrasonic Altimeter that can be used on a UAV? I know there are several heli Ultrasonic Altimeters out there but I'm interested in one specifically for a fixed-wing UAV.

Thanks

:)

[treehog]

and what princible does it use

There is some sort of gizzmo for the wings to detect one wing is lowwer altitude than another for stabilty use
some link in here forget where it is will look around for it

Ralf
this thread explains a bit half way down

http://www.rcgroups.com/forums/showthread.php?t=579335

[DiveBombDave]

I've been looking at this laser (http://www.opticsplanet.net/opti-logic-range-finder-rs800.html) one.

Dave

[clolson]

I've been looking at this laser (http://www.opticsplanet.net/opti-logic-range-finder-rs800.html) one.


This is the first time I've looked at any thing like this, but the specs list a 4 yard minimum range. Does that mean it would not be very helpful for timing your flare in an autolanding?

Curt.

[Magician]

Does anyone know of a good Fixed-wing Ultrasonic Altimeter that can be used on a UAV? I know there are several heli Ultrasonic Altimeters out there but I'm interested in one specifically for a fixed-wing UAV.
:)

The problem you run into with the ultrasonic range finders is that they are very range limited. We fly the SonaSwitch (http://edpcompany.com/sonaindex.html) on a helicopter and it works well but only to 20-25'. Suits the needs for launch and landing for a helicopter. When it was flown on a fixed wing the range was even less (5-10') because the forward speed caused it to essentially fly away from the echo.

What is the speed of the intended vehicle? If it is slow enough than maybe the acoustic sensor would work. And what range and resolution are you looking for?

The laser system that was linked to is made very cheaply and did not perform well in testing. It does have a very high minimum range as Curt pointed out and this is due to the rudimetry circuitry they use for a timing circuit. Sorry, can't provide too many details since I'm an Aero guy, not EE.

Still looking for a small radar altimeter, any one got one?

Later

[UAVeez]

I've been looking at this laser (http://www.opticsplanet.net/opti-logic-range-finder-rs800.html) one.

Dave
Looks like a great fit. I just wish it wasn't so expensive.

[UAVeez]

The problem you run into with the ultrasonic range finders is that they are very range limited. We fly the SonaSwitch (http://edpcompany.com/sonaindex.html) on a helicopter and it works well but only to 20-25'. Suits the needs for launch and landing for a helicopter. When it was flown on a fixed wing the range was even less (5-10') because the forward speed caused it to essentially fly away from the echo.

What is the speed of the intended vehicle? If it is slow enough than maybe the acoustic sensor would work. And what range and resolution are you looking for?

The laser system that was linked to is made very cheaply and did not perform well in testing. It does have a very high minimum range as Curt pointed out and this is due to the rudimetry circuitry they use for a timing circuit. Sorry, can't provide too many details since I'm an Aero guy, not EE.

Still looking for a small radar altimeter, any one got one?

Later

Found this one. Not sure how expensive it is though.

http://www.roke.co.uk/mra/

This is interesting...
http://www.mwrf.com/Articles/ArticleID/10583/10583.html

[treehog]

http://www.rcgroups.com/forums/showthread.php?t=591019

Ralf

[Magician]

Found this one. Not sure how expensive it is though.
http://www.roke.co.uk/mra/


We have tried the Roke systems and have had poor reliability issues. Both units we had failed after a very short time. One was being tested on a manned aircraft and after only an hour of flight it just stopped working. I have since found other folks with the same problems.

The most promising radar technology that I would like to test is the SPIDER 650 from Multispectral Solutions (http://www.multispectral.com/).

[cobaltdan]

Found this one. Not sure how expensive it is though.

http://www.roke.co.uk/mra/

This is interesting...
http://www.mwrf.com/Articles/ArticleID/10583/10583.html




we have used the roke mk4 with good results. it has good differentiation between the actual ground and ground foliage. although, i did think the unit was overpriced.

-daniel preston
atair aerospace