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Re: Sensors in Motion Launches MEMS-Based Inertial Nav System

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  Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Lofty Goat <rlwatkins@gmail.com> - 2015-07-26 23:44 -0500
    Re: Sensors in Motion Launches MEMS-Based Inertial Nav System jimp@specsol.spam.sux.com - 2015-07-27 22:52 +0000
      Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Jackpol11@hotmail.com - 2015-07-28 16:41 -0400
        Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <poutnik4nntp@gmail.com> - 2015-08-01 12:32 +0200
          Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Jackpol11@hotmail.com - 2015-08-02 15:51 -0400
            Re: Sensors in Motion Launches MEMS-Based Inertial Nav System jimp@specsol.spam.sux.com - 2015-08-02 20:29 +0000
            Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <poutnik4nntp@gmail.com> - 2015-08-03 01:12 +0200
              Re: Sensors in Motion Launches MEMS-Based Inertial Nav System jimp@specsol.spam.sux.com - 2015-08-03 00:07 +0000
                Re: Sensors in Motion Launches MEMS-Based Inertial Nav System John Gogo <jfgogo22@yahoo.com> - 2015-08-02 19:32 -0700
                Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Jackpol11@hotmail.com - 2015-08-03 12:17 -0400
                  Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <Poutnik4NNTP@gmail.com> - 2015-08-03 19:00 +0200
                    Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Bohuš Matuška <bohu@paranetnet.net> - 2015-08-03 18:01 +0000
                      Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <Poutnik4NNTP@gmail.com> - 2015-08-03 20:31 +0200
                        Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Bohuš Matuška <bohu@paranetnet.net> - 2015-08-03 19:28 +0000
                    Re: Sensors in Motion Launches MEMS-Based Inertial Nav System jimp@specsol.spam.sux.com - 2015-08-03 18:01 +0000
                      Re: Sensors in Motion Launches MEMS-Based Inertial Nav System John Gogo <jfgogo22@yahoo.com> - 2015-08-03 19:47 -0700
                    Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Jackpol11@hotmail.com - 2015-08-03 14:52 -0400
                      Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <poutnik4nntp@gmail.com> - 2015-08-03 23:00 +0200
                        Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Ignorant Raving Crackpot <ignorantravingcrackpot@gmail.com> - 2015-08-03 14:32 -0700
                        Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Jackpol11@hotmail.com - 2015-08-06 10:36 -0400
                          Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <poutnik4nntp@gmail.com> - 2015-08-07 07:58 +0200
                          Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <poutnik4nntp@gmail.com> - 2015-08-07 08:35 +0200
                            Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Jackpol11@hotmail.com - 2015-08-07 10:13 -0400
                              Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <poutnik4nntp@gmail.com> - 2015-08-08 00:26 +0200
                                Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Jackpol11@hotmail.com - 2015-08-07 22:25 -0400
                                  Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Poutnik <poutnik4nntp@gmail.com> - 2015-08-08 07:14 +0200
                  Re: Sensors in Motion Launches MEMS-Based Inertial Nav System jimp@specsol.spam.sux.com - 2015-08-03 17:57 +0000
      Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2015-07-30 11:03 -0400
        Re: Sensors in Motion Launches MEMS-Based Inertial Nav System Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2015-08-04 03:10 -0400
          Re: Sensors in Motion Launches MEMS-Based Inertial Nav System jimp@specsol.spam.sux.com - 2015-08-04 17:24 +0000
    Re: Sensors in Motion Launches MEMS-Based Inertial Nav System wobbly <wobbly@dont-email.me> - 2015-07-28 22:01 +0000

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#359878

Dne 06/08/2015 v 16:36 Jackpol11@hotmail.com napsal(a):
> 
> For that I looked up
> https://en.wikipedia.org/wiki/Gimbal#Inertial_navigation
> which fills in more detail about the function of gimbals. The article
> has a number of errors, since it is apparently written by someone with
> no actual knowledge because he says that gimbal angles are measured to
> provide the 9 direction cosines needed for navigation. instead, the 3
> resolvers (transformers) automatically  parcel out all the gyro
> signals to the proper axes.
> Therefore I edited it, which was apparently effective immediately.
> (See inertial navigation section).
> 
> John Polasek
> 
Are you aware this may be against
WP editing and mainly source policy ?

Original or personal opinion based information
is not allowed, unless referenced to external resources.

-- 
Poutnik ( the Czech word for a wanderer )

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#359882

Dne 06/08/2015 v 16:36 Jackpol11@hotmail.com napsal(a):

> ............because he says that gimbal angles are measured to
> provide the 9 direction cosines needed for navigation. instead, the 3
> resolvers (transformers) automatically  parcel out all the gyro
> signals to the proper axes.

"These resolvers perform an automatic matrix transformation according to
each gimbal angle.......... The gimbal angle is never measured. "

If "The gimbal angle is never measured. "
than what does mean
"according to each gimbal angle" ?

-- 
Poutnik ( the Czech word for a wanderer )

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#359919

On Fri, 7 Aug 2015 08:35:26 +0200, Poutnik <poutnik4nntp@gmail.com>
wrote:

>Dne 06/08/2015 v 16:36 Jackpol11@hotmail.com napsal(a):
>
>> ............because he says that gimbal angles are measured to
>> provide the 9 direction cosines needed for navigation. instead, the 3
>> resolvers (transformers) automatically  parcel out all the gyro
>> signals to the proper axes.
>
>"These resolvers perform an automatic matrix transformation according to
>each gimbal angle.......... The gimbal angle is never measured. "
>
>If "The gimbal angle is never measured. "
>than what does mean
>"according to each gimbal angle" ?
The stable platform coordinate system is separated from the airplane's
coordinate system by rotations through roll pitch and yaw angles.
Platform error signals must be transformed by these rotations to make
sense in the other coordinate system. Therefore the axles are each
fitted out with a resolver that automatically does the coordinate
transformation electromagnetically.
The stator and the rotor each have a pair of windings at right angles
to each other like an L or like the 2 base vectors X, Y. A gyro signal
is connected to one of the stator windings say X. It shows up in the
rotor as the components  X', Y' having been transformed by the
rotation matrix for that particular axis. Then the signals X', Y' are
applied to another subsequent resolver to take care of that rotation.
It is all very nifty and it is apparent that almost no one on earth
understands resolvers. 
This makes it quite apparent that nobody's writing down the gimbal
angles and finding the 9 direction cosines. 
John Polasek

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#359966

Dne 07/08/2015 v 16:13 Jackpol11@hotmail.com napsal(a):
> On Fri, 7 Aug 2015 08:35:26 +0200, Poutnik <poutnik4nntp@gmail.com>
> wrote:
> 
>> Dne 06/08/2015 v 16:36 Jackpol11@hotmail.com napsal(a):
>>
>>> ............because he says that gimbal angles are measured to
>>> provide the 9 direction cosines needed for navigation. instead, the 3
>>> resolvers (transformers) automatically  parcel out all the gyro
>>> signals to the proper axes.
>>
>> "These resolvers perform an automatic matrix transformation according to
>> each gimbal angle.......... The gimbal angle is never measured. "
>>
>> If "The gimbal angle is never measured. "
>> than what does mean
>> "according to each gimbal angle" ?
> The stable platform coordinate system is separated from the airplane's
> coordinate system by rotations through roll pitch and yaw angles.
> Platform error signals must be transformed by these rotations to make
> sense in the other coordinate system. Therefore the axles are each
> fitted out with a resolver that automatically does the coordinate
> transformation electromagnetically.
> The stator and the rotor each have a pair of windings at right angles
> to each other like an L or like the 2 base vectors X, Y. A gyro signal
> is connected to one of the stator windings say X. It shows up in the
> rotor as the components  X', Y' having been transformed by the
> rotation matrix for that particular axis. Then the signals X', Y' are
> applied to another subsequent resolver to take care of that rotation.
> It is all very nifty and it is apparent that almost no one on earth
> understands resolvers. 

So you are one of the few manufacturers of the gimbal gyroscopes....

> This makes it quite apparent that nobody's writing down the gimbal
> angles and finding the 9 direction cosines. 

Why do you ever think anybody would want to do that ?
( unless employing army of small inteligent dwarf )

Resolvers do that implicitly.


-- 
Poutnik ( the Czech word for a wanderer )

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#359980

On Sat, 8 Aug 2015 00:26:52 +0200, Poutnik <poutnik4nntp@gmail.com>
wrote:

>Dne 07/08/2015 v 16:13 Jackpol11@hotmail.com napsal(a):
>> On Fri, 7 Aug 2015 08:35:26 +0200, Poutnik <poutnik4nntp@gmail.com>
>> wrote:
>> 
>>> Dne 06/08/2015 v 16:36 Jackpol11@hotmail.com napsal(a):
>>>
>>>> ............because he says that gimbal angles are measured to
>>>> provide the 9 direction cosines needed for navigation. instead, the 3
>>>> resolvers (transformers) automatically  parcel out all the gyro
>>>> signals to the proper axes.
>>>
>>> "These resolvers perform an automatic matrix transformation according to
>>> each gimbal angle.......... The gimbal angle is never measured. "
>>>
>>> If "The gimbal angle is never measured. "
>>> than what does mean
>>> "according to each gimbal angle" ?
>> The stable platform coordinate system is separated from the airplane's
>> coordinate system by rotations through roll pitch and yaw angles.
>> Platform error signals must be transformed by these rotations to make
>> sense in the other coordinate system. Therefore the axles are each
>> fitted out with a resolver that automatically does the coordinate
>> transformation electromagnetically.
>> The stator and the rotor each have a pair of windings at right angles
>> to each other like an L or like the 2 base vectors X, Y. A gyro signal
>> is connected to one of the stator windings say X. It shows up in the
>> rotor as the components  X', Y' having been transformed by the
>> rotation matrix for that particular axis. Then the signals X', Y' are
>> applied to another subsequent resolver to take care of that rotation.
>> It is all very nifty and it is apparent that almost no one on earth
>> understands resolvers. 
>
>So you are one of the few manufacturers of the gimbal gyroscopes....
I'm not acquainted with that term. 
I spent 20 years in the 50s and 60s analyzing inertial guidance
systems. Apparently the 1st time you ever heard of them was last week.
>> This makes it quite apparent that nobody's writing down the gimbal
>> angles and finding the 9 direction cosines. 
>
>Why do you ever think anybody would want to do that ?
>( unless employing army of small inteligent dwarf )
Because 9 direction cosines was the previous description in Wiki
before I modified the article. 
You seemed perfectly willing to measure the angle--and then what? Then
you need 3 cascaded matrices to take care of each of the 3 angles, the
product giving you your 9 direction cosines the hard way!
>Resolvers do that implicitly.
You never knew how resolvers worked until I told you and even the Wiki
discussion of resolvers is a jumble. They describe 1 winding on the
rotor and 2 windings on the stator, without realizing that such cannot
be cascaded in a chain to handle more than one angle.
Why do you continue to struggle? You're out of your depth.
John Polasek

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#359988

Dne 08/08/2015 v 04:25 Jackpol11@hotmail.com napsal(a):
> On Sat, 8 Aug 2015 00:26:52 +0200, Poutnik <poutnik4nntp@gmail.com>
> wrote:
> 

>>> It is all very nifty and it is apparent that almost no one on earth
>>> understands resolvers. 
>>
>> So you are one of the few manufacturers of the gimbal gyroscopes....

> I'm not acquainted with that term. 

Yo did  not get the joke.
If almost no one on Earth but you understands resolvers
than almost no one on Earth but you can manufacture them.

> I spent 20 years in the 50s and 60s analyzing inertial guidance
> systems. Apparently the 1st time you ever heard of them was last week.

Apparently wrong again.
And, it is long time since than, so technology went long way..
No wonder why you are lost, frozen in 50s and 60s ( no offence )

It is typical for aging people, dwelling on things of their bets years.
No offence intended, I will be probably the same.

>>> This makes it quite apparent that nobody's writing down the gimbal
>>> angles and finding the 9 direction cosines. 
>>
>> Why do you ever think anybody would want to do that ?
>> ( unless employing army of small inteligent dwarf )

> Because 9 direction cosines was the previous description in Wiki
> before I modified the article. 

You did not get why they were mentined.

> You seemed perfectly willing to measure the angle--and then what? Then

Again, your misunderstanding.
No reason for measuring angle.
Resolvers measure the codines directly and implicitly.

> you need 3 cascaded matrices to take care of each of the 3 angles, the
> product giving you your 9 direction cosines the hard way!

Finally you got it.

>> Resolvers do that implicitly.
> You never knew how resolvers worked until I told you and even the Wiki
> discussion of resolvers is a jumble. 

You semm do not know how they work until now yet,
as they measure the cosines.


-- 
Poutnik ( the Czech word for a wanderer )

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#359537

In sci.physics Jackpol11@hotmail.com wrote:
> On Mon, 3 Aug 2015 00:07:56 -0000, jimp@specsol.spam.sux.com wrote:
> 
>>In sci.physics Poutnik <poutnik4nntp@gmail.com> wrote:
>>> Dne 02/08/2015 v 21:51 Jackpol11@hotmail.com napsal(a):
>>>> On Sat, 1 Aug 2015 12:32:41 +0200, Poutnik <poutnik4nntp@gmail.com>
>>>> wrote:
>>>> 
>>>>> Dne 31/07/2015 v 22:58 Jackpol11@hotmail.com napsal(a):
>>>>>
>>>>>> I didn't hear you say anything helpful, sure they are a different kind
>>>>>> of gyroscope that hopefully can compete in accuracy with the
>>>>>> conventional ones.  If their function is not to keep a local vertical,
>>>>>> and keep gravity out of the accelerometers,then what is it?
>>>>>
>>>>> Classical meaning of gyroscope
>>>>> as measure against to be rotated
>>>>> misses the etymology of the word.
>>>>>
>>>>> Freely translated it is "noticing the rotation",
>>>>> and this is followed by MEMS gyroscopes .
>>>>>
>>>>> https://www.google.cz/search?q=MEMS+gyroscope
>>>>>
>>>>> http://www.quora.com/How-does-a-MEMS-gyroscope-work
>>>>>
>>>>> https://en.wikipedia.org/wiki/Vibrating_structure_gyroscope
>>>>>
>>>>> https://www.youtube.com/watch?v=A03AENwOVNY
>>>>> ( MEMS gyroscopes - A revolutionary way to interface with the real world
>>>>> (ePresentation) )
>>>>>
>>>>> http://electroiq.com/blog/2010/11/introduction-to-mems-gyroscopes/
>>>> I've read one of the articles  by the manufacturer, and I see these
>>>> gyroscopes are nothing more than rate gyroscopes which are not really
>>>> gyroscopes, but sensors of angular rate. They are of great use in
>>> 
>>> Greek gyros "a circle" (see gyre (n.)) + skopos "watcher" (see scope
>>> (n.1)), because the device demonstrates that the earth rotates.
>>> 
>>> Gyroscope IS a sensor of angular rate.
>>
>>A gyroscope CAN BE a sensor of angular rate, and several other things
>>including just a toy.
> A rate gyroscope is elastically restrained with a spring.
> A true gyroscope as used in an inertial guidance system is insulated
> against the angular rates by virtue of being mounted in gimbals, from
> which the angles can be read for navigation computation. It tries to
> maintain a rigid orientation in an inertial space. Deviation sensed by
> gyroscopes produce correction torques at the gimbals.
> John Polasek

The word "gyroscope" is generic and implies nothing more than a spinning
wheel with freedom of rotation in all three axes.

It is only after you add qualifiers that it has any particular characteristic
such sensing angular rate, e.g. a rate gyroscope.

What does this gyroscope sense?

http://www.arborsci.com/original-gyroscope?gclid=CjwKEAjwovytBRCdxtyKqfL5nUISJACaugG13eQG-9_7h_Rj2s-uS6FCF-qptjrCEI6hSCrZn6aZ0hoCFNrw_wcB


-- 
Jim Pennino

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#359104

On 29/07/2015 7:58 PM, jimp@specsol.spam.sux.com wrote:
> If you need GPS to drive through a tunnel, then I pity everyone else
> on the road with you.
>
> You sound like one of those people who follow their GPS and drive off
> the end of a pier when the ferry boat isn't there.


You've never driven in Montreal have you?

	Yousuf Khan

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#359599

On 30/07/2015 2:10 PM, jimp@specsol.spam.sux.com wrote:
> It is irrelevant whether or not I have driven in any particular place.
>
> Do they not have paved roads and road signs in Montreal?

As I said, you've never driven in Montreal. The roads are paved in 
potholes, and the signs are all in French. And lights in tunnels are hit 
and miss. Not hard to miss your off-ramp in a dark tunnel while your 
eyes are being jostled out of their sockets, meanwhile you're trying to 
translate the French into English in your mind.

> Saying someone needs GPS to drive through a tunnel or a parking garage
> is just plain silly.

It is in place where you've been, but not in places where you've never 
been before. Your own little perspective on life is of very little 
relevance to the real world.

	Yousuf Khan

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#359631

In sci.physics Yousuf Khan <bbbl67@spammenot.yahoo.com> wrote:
> On 30/07/2015 2:10 PM, jimp@specsol.spam.sux.com wrote:
>> It is irrelevant whether or not I have driven in any particular place.
>>
>> Do they not have paved roads and road signs in Montreal?
> 
> As I said, you've never driven in Montreal. The roads are paved in 
> potholes, and the signs are all in French. And lights in tunnels are hit 
> and miss. Not hard to miss your off-ramp in a dark tunnel while your 
> eyes are being jostled out of their sockets, meanwhile you're trying to 
> translate the French into English in your mind.

Oh boo hoo.

Try driving somewhere where the roads are mostly unpaved and the few
signs there are are in Korean.
 
>> Saying someone needs GPS to drive through a tunnel or a parking garage
>> is just plain silly.
> 
> It is in place where you've been, but not in places where you've never 
> been before. Your own little perspective on life is of very little 
> relevance to the real world.

Any five year old can find the end of a tunnel.

Once you exit the tunnel, it only takes a few seconds for GPS to relock
unless you spent several hours inside the tunnel.


-- 
Jim Pennino

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#358941

Lofty Goat wrote:

> On Sun, 26 Jul 2015 13:33:20 +0000, Fritz Köhler wrote:
> 
>> jimp wrote:
>> 
>>> Sam Wormley <swormley1@gmail.com> wrote:
>>>> Sensors in Motion Launches MEMS-Based Inertial Nav System
>>> 
>>> It still needs calibration by something like GPS shit head.
>> 
>> MEMS does not need GPS calibration, asshat. That's the whole idea with
>> inertial MEMS, they calibrate by completely other means. What an idiot,
>> lol, to calibrate MEMS by GPS.
> 
> Given your great willingness to speak up, I wish you knew what you were
> talking about.  Pennino may blather some, but at least he knows things:
> "MEMS" doesn't necessarily "require calibration" or "not require
> calibration".  It's an acronym for micro-electro-mechanical-system.
> MEMS-based *inertial guidance systems* do require calibration.  They
> drift.  Some of them drift less than others, but they all drift.

You must be at least as stupid jimp is. The magnetic sensor and the 
accelerometer are not drifting. Those needs calibration before use in 
whatever orientation/navigation application.

The main source of (signal) drift comes from the gyros used. Those are 
prone to drift indeed. 

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