2
\$\begingroup\$

I'm currently working on a project where I am pulling readings from 3 Gyroscopes (STM L3G4200D) to a Microcontroller (TI MSP430) and sending orientation data to the user.

I've been reading up on gyroscope data collection and it sounds as though gyroscope readings tend to "drift" over long periods. Would there be a good way of tracking or correcting for this drift?

\$\endgroup\$
  • \$\begingroup\$ Is this the only sensor you have? Gyroscopes and accelerometers are often used in conjunction to help calibrate eachother. This page has a good write-up. \$\endgroup\$ – David Oct 11 '13 at 16:41
4
\$\begingroup\$

You need some other way to measure absolute attitude in order to correct for the long-term drift of your (rate) gyros so that you can use them for meaningful short-term measurements.

Some systems use accelerometers to measure the gravity vector to establish roll and pitch references (but this requires that there are no other accelerations involved) and magnetometers to establish a yaw reference.

Other systems use multiple (two or three) GPS receivers to do interferometry on the GPS signals in order to establish an absolute attitude reference. This is harder to do, but can be done even while on the move (accelerating).

The most sophisticated systems combine all four kinds of information (rate gyro, acceleration, magnetometer and GPS, typically using a Kalman filter) in order to provide the most robust solution.

\$\endgroup\$
  • \$\begingroup\$ +1 for pointing out that these are not gyros but rate gyros. They will by definition incur integral errors - i.e. drift. \$\endgroup\$ – placeholder Oct 11 '13 at 18:38
  • \$\begingroup\$ @rawbrawb: Regular gyros drift, too. It's just that with rate gyros, a simple offset error becomes drift after integration. \$\endgroup\$ – Dave Tweed Oct 11 '13 at 19:13
  • \$\begingroup\$ I'd just say you nailed the answer. Excellent response. \$\endgroup\$ – Bob Oct 11 '13 at 19:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.