Re: [Paparazzi-devel] [Lisa/L + MTi-G] vs [Lisa/L + MTi + GPS]

[Volodymyr Khudyakov]

Dear Rui
Problem not in IMU itself...
When you flew BIG and HEAVY plane, you main problem - reliability.
I personally have last time problem with CHIMU ( Christopher know... ) and
only manual control is my only salvation. Fortunately, I seen my plane.
Think twice about cost, especially with hidden cost of plane crash...

Sincerely
Vladimir

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Message: 3
Date: Sun, 15 Jul 2012 20:42:15 +0000
From: Rui Costa <address@hidden>
To: address@hidden
Subject: Re: [Paparazzi-devel] [Lisa/L + MTi-G] vs [Lisa/L + MTi +
        GPS]
Message-ID:
        <address@hidden>
Content-Type: text/plain; charset="iso-8859-1"

Thank you Christophe,

Will be to incorporate on a 20Kg gas engine aircraft and someone said to
use the MTi-g. So, maybe I will try cheaper solutions first. Have to do
some tests with the motor running because of vibration.

The old Booz IMU will be better that Aspirin IMU or Aspirin is the best
solution out there for the paparazzy autopilots at a good price?


Cheers
Rui Costa
On Sun, Jul 15, 2012 at 7:31 PM, Christophe De Wagter
<address@hidden>wrote:

> If the GPS is not taken into account in the full extended kalman filter
> running on the Blackfin DSP of the XSens (MtiG) you probably do not want
to
> go through the expenses of the XSens at all.
>
> a) either full AHRS (with GPS) in the XSens -> MTiG, and make sure your
> Magnetometer is well calibrated and positioned such that it has no
> interference.
> b) or the attitude is determined in paparazzi: Then you can also replace
> the XSens MTi with an Aspirin 2.0 IMU or something like that. The only
> advantage of the Mti would be it is more vibration resistant and
calibrated.
>
> So I personally do not see many reason to ever use an Mti. It is too slow
> for quadrotors, and not sufficiently compensated for airplanes, and if you
> do the compensation in paparazzi anyway there are cheaper options. The
> Mti-G on the other hand, with its aerospace (kalman) filter has proven to
> be a reliable AHRS when the magnetometer is well calibrated.
>
> -Christophe
>
>
>
> On Sun, Jul 15, 2012 at 3:16 PM, Rui Costa <address@hidden>wrote:
>
>> Hello all,
>>
>> I would like to know your opinion about this two configurations:
>>
>>
>> 1. Lisa/L + MTi-G
>> 2. Lisa/L + MTi + u-blox LEA GPS
>>
>> The second option will be cheaper. But I don't know if it will work and
>> in terms of performance what should be better?
>>
>>
>> It's for an fixed wing UAV of about 20Kg.
>>
>>
>>
>> Cheers
>> Rui Costa
>>
>> _______________________________________________