Using many cheap accelerometers to reduce error - Page 3

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Re: Using many cheap accelerometers to reduce error
snipped-for-privacy@gmail.com wrote in

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My units used a GE IRU (Inertial Reference Unit)  They are about a 7  
inch cube and run about 50k each in quantity.  Singles usually cost  
you about $100k each.  We used them to keep a satellite dish aimed  
while the base it was mounted on was in motion (mobile sat comms).

<http://pdf.aeroexpo.online/pdf/ge-aviation/9181-series-inertial-
reference-unit/169836-10741.html>
3 to 5 mil accuracy.

Re: Using many cheap accelerometers to reduce error
On Sun, 10 Feb 2019 08:28:39 -0800 (PST),
snipped-for-privacy@gmail.com wrote:

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Would it?  If they're on the same platform, the coupling is the same
no matter what additional force is on them (superposition).

Re: Using many cheap accelerometers to reduce error
On Monday, February 11, 2019 at 11:51:42 AM UTC+11, snipped-for-privacy@notreal.com wrote:
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Krw happens to be wrong here. The force imposed by rotational acceleration does vary in proportion to the distance from the centre of rotation, as Rick pointed out, and krw seems to have failed to comprehend.

--  
Bill Sloman, Sydney

Re: Using many cheap accelerometers to reduce error
On Sunday, February 10, 2019 at 7:51:42 PM UTC-5, snipped-for-privacy@notreal.com wrote:
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Eh?  If there is rotation each sensor will have a separate acceleration with different distances from the center of rotation.  The different forces stimulate the different sensors to different frequencies.  Don't the frequencies vary with force?  

Rick C.  

Re: Using many cheap accelerometers to reduce error
On Sun, 10 Feb 2019 22:23:10 -0800 (PST),
snipped-for-privacy@gmail.com wrote:

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Is it or is it not a linear system?  Ever hear of superposition?
Didn't think so.
  

Re: Using many cheap accelerometers to reduce error
On Tuesday, February 12, 2019 at 2:22:56 PM UTC+11, snipped-for-privacy@notreal.com wrote:
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Krw's capacity not to think is remarkable, and frequently demonstrated, as here.

With anybody else you'd have to wonder what they were thinking, but krw doesn't think - he just consults his preprogrammed attitudes. Rick isn't a right-wing lunatic so he has to be wrong ...

--  
Bill Sloman, Sydney

Re: Using many cheap accelerometers to reduce error
On 2/10/19 12:58 AM, JS wrote:
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If you do it all on one wafer, you'll certainly have systematic error.

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Using many cheap accelerometers to reduce error
On 2/9/19 6:13 PM, John Larkin wrote:
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Of course gyros don't measure acceleration. ;)

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
We've slightly trimmed the long signature. Click to see the full one.

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