Re: [Paparazzi-devel] Sonar

[Achim Walther]

Nathan,

as far as my experience goes sonar does not reliably work on a fixed
wing that's faster than 10 m/s. I tested the SRF02 and SRF08 so far. The
SRF02 is of no use at all. The SRF08 is much better but nevertheless it
sometimes reads false values. You can adjust its sensitivity via I2C,
but if you set it higher, then it reads distances like 3 meters when
more than 30 meters above ground, and if sensitivity is set lower it
will read 0 at 2 meters.

I guess the cause of false readings is noise coming from the engines or
wings. So like Gautier said, maybe the maxbotix are better. In that case
I would like to hear some positive test results.

Otherwise, there are alternatives like Laser rangers or modified optical
mouse sensors (optical flow) which are either too expensive / heavy or
not yet technically mature.

Regards, Achim.


Nathan Aherne wrote:
> I have read the devel list about altitude sensors for landing and I have
> noticed there is a module for the maxbotix sonar for the booz. I would
> like to use the sonar if possible for landings in a fixed wing aircraft
> on the TWOG. Will the sonar work for landings and will the booz module
> work with a fixed wing aircraft?
> 
> The sonar I am looking at is -
> http://www.sparkfun.com/commerce/product_info.php?products_id=9496
> 
> 
> Kindest regards,
> 
> Nathan Aherne