Improving iPhone AR (Tool)Kit by using the Gyroscope

I'm using iPhone AR Kit and its fork, iPhone AR Toolkit, but I'm trying to improve the user experience by using the gyroscope when it's available.

For those of you who used the kits, do you have 开发者_如何转开发any idea on how to do this ? My first thought was to get the gyroscope yaw to get a more precise azimuth value.

So I have to questions :

• Does anyone used the AR Kit linked above, and have thoughts on including gyroscope in it ?
• Is it a good idea to mix gyroscope and compass data to get a more precise value of the azimuth ?

Gyroscopes measure rotational velocity, so the gyro output will be in change in yaw per second (e.g rad/s) rather than an absolute yaw. There are various methods for trying to use gyros for "dead reckoning" of orientation, but in practice while they're very accurate over the short term, integrating gyro read-outs to determine orientation "drifts" significantly, so you have to keep recalibrating against some absolute measure.

It would be very trivial to use the gyro to interpolate between compass readings, or calculate the bearing based on the gyro only for short fast motions while the compass catches up, but properly fusing the compass and gyro isn't trivial. There's a talk here on integrating sensor for Android that might be a good start. The standard method of fusing sensors is to use a Kalman Filter, there's an introduction here. They're fairly involved tools, you need a good model of your sensor errors for example.