Previous 1 2 Next 16 Replies Latest reply: Mar 7, 2011 10:08 AM by jacks1982
nitpicker330 Level 1 Level 1 (0 points)
Hi,
a question for the tech experts out there!!

I have an App installed called "gyroscope" that is supposed to utilize the phones new 3 Axis Gyro sensor system.
I tried it out whilst flying myself in an Aircraft yesterday ( yes I'm a Pilot and I'm aware of how a Gyro works ) and when the Aircraft banks left or right the i-phone Gyro shows no bank at all. If the phone had a real gyro installed then it should have shown the aircraft bank.So it seems the Gyro is rubbish or just a gimmick.

You need to actually move the phone itself to show any change on the phones gyro.

Whats the deal?

Thanks

i-phone 4, iOS 4
  • tonefox Level 6 Level 6 (8,830 points)
    If the phone remained in a constant position relative to the aircraft, I would not expect the gyro to react, as the banking causes "down" within the aircraft not to vary, i.e. "down" will still be through the seat. The gyro senses no more sideways force than you do.
  • Dave Hutch Level 4 Level 4 (1,465 points)
    I don't understand why it should have to be "in relation to the aircraft".
    I thought gyros reacted to any movement themselves, without reference to external objects?
    The phone would change its orientation in space so the gyros should react? Have I got that all wrong?
  • tonefox Level 6 Level 6 (8,830 points)
    It was just a shot in the dark.

    I'm not (demonstrably) any form of expert. You might find the description here helpful. I would hesitate to describe it as rubbish or gimmick.

    http://www.ifixit.com/Teardown/iPhone-4-Gyroscope-Teardown/3156/1
  • nitpicker330 Level 1 Level 1 (0 points)
    And a bad shot in the Dark!!

    All Aircraft, Missiles, Submarines etc have Gyro systems fitted. The new types are Laser Gyros and have been for 20 years now. A Gyro has "Rigity in Space" meaning once aligned it remains stable irrespective of what the host platform does and therefore can be used to sense changes in Attitude and Position.

    Now, in a real Aircraft whenever you Roll Pitch or Yaw the Gyro senses this and displays to the Pilot this on his Attitude display ( amongst others system displays)

    The i-phone Gyro doesn't due to it's current software programming is therefore not a "real" Gyro.


    I know one App programmer that is currently testing the Gyro after modifying the software code to more correctly utilise the Gyro. Hopefully he will be successful.
  • tonefox Level 6 Level 6 (8,830 points)
    Is that the new app called, simply, "Gyroscope"? It gives you a representation of a real gyroscope, with readings for roll, pitch and yaw. Have a look - it's free. It should certainly tell you whether or not the iPhone gyroscope is rubbish.
  • Malcolm Rayfield Level 7 Level 7 (28,070 points)
    Try iPhone 4 Gyroscope Aircraft Attitude Indicator
    <http://itunes.apple.com/ca/app/airplane-gyroscope-attitude/id385491648?mt=8>
  • nitpicker330 Level 1 Level 1 (0 points)
    I've tried them all and none work correctly in an Aircraft.

    The developer of Aircraft Attitude indicator is also a Pilot and will be modifying his to remove the accelerometer input. Seems it interfears with the gyro and causes it to reset all the time.

    I await his update to see if it works

    Message was edited by: nitpicker330
  • EBSkater Level 2 Level 2 (490 points)
    I don't know physics (will be taking it later this year), but is it at all possible for the smaller motions made by a person to be picked up by the gyro, yet the enlarged scale of the airplane, yet keeping the same tiny gyro, possibly interfering with it working the way you'd think?

    Like I'm guessing that if you walked the radius of a 20 foot circle, it would register on the gyro, yet it wouldn't register if you walked a mile radius of a circle...

    Does that make any sense at all?
  • nitpicker330 Level 1 Level 1 (0 points)
    Ahhh No.
  • KC7GNM Level 4 Level 4 (2,735 points)
    tonefox wrote:
    If the phone remained in a constant position relative to the aircraft, I would not expect the gyro to react, as the banking causes "down" within the aircraft not to vary, i.e. "down" will still be through the seat. The gyro senses no more sideways force than you do.

    Wrong. The iphone should have registered movement because the phone banked with the plane. Do you think that planes gyro doesn't move when you bank? It is fixed in the plane so would be the same as holding the iphone steady in the plane.
  • KC7GNM Level 4 Level 4 (2,735 points)
    EBSkater wrote:
    I don't know physics (will be taking it later this year), but is it at all possible for the smaller motions made by a person to be picked up by the gyro, yet the enlarged scale of the airplane, yet keeping the same tiny gyro, possibly interfering with it working the way you'd think?

    Like I'm guessing that if you walked the radius of a 20 foot circle, it would register on the gyro, yet it wouldn't register if you walked a mile radius of a circle...

    Does that make any sense at all?

    No not at all. Physics would have taught you that.
  • mooneypilot94 Level 1 Level 1 (0 points)
    Hi! I am the developer of the Attitude Indicator app, I just did a second test flight with the new code and it still has problems. Its weird because the new code uses the "raw" gyroscope output of the iPhone 4, no accelerometer at all, just the Gyro, on the ground it works perfect, but not in the air. I am talking back and forth with Apple tech support to see why this would be... I Also want this to work since I fly as well and would like it as a backup. Apple says my code should work, I sent them more samples of my code today, so we will see. I wont give up on this and will keep you updated.

    Thanks!
  • nitpicker330 Level 1 Level 1 (0 points)
    Gidday MoooneyPilot...........any updates?

    Thanks.
  • mooneypilot94 Level 1 Level 1 (0 points)
    Hi! Sorry for the delay in reply. Yes, I have done 3 more test flights and have submitted an app update last week (for the Airplane Gyroscope Attitude Indicator app). Hopefully the update will be approved and released soon! It turns out the stock Gyro output code is not meant to work in airplanes, it is optimized for games (makes sense), I talked a lot to Apple about this issue, they were very helpful. I think I found a solution by using the "raw" Gyro output, and filtering it myself, I test flew today in my trusty Mooney and it seemed much better, I am still fine tuning it, and will keep working on it until I get it perfect!

    Leroy
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