Originally Posted by Papabravo

Which brings us full circle back to the original question about the measurement of an angular velocity in degrees/second and what it actually refers to. We think we understand the measurement for a mechanical gyro, but I am less clear for the other types exactly what angular velocity is being measured. Assuming we can get our arms around that one, then we need to understand how, as a figure of merit, we could apply different non-mechanical gyros to a given application. Like erecting our robots from a supine position. CMOL(Chuckling mildly out loud)

Originally Posted by dusko

Check this one:

https://www.unitedhobbies.com/UNITED...idProduct=4320

I know, it's not the analog interface, but the price seems to be right for testing/learning.

Originally Posted by Papabravo

I'm not sure that Coriolis force and the spinning gyro are related. I'll have to get back to you on that one. The links you provided, including the movie, were not much help in understanding the undelying physics of the MEMS and Piezo devices. That's hardly surprising since I've not previously considered similar systems.

It was my impression that the Coriolis force is responsible for the direction of flow in a flush toilet and is a nearly negligible effect when compared to the spinning rotor of a standard gyro when the direction of its angular momentum vector changes. In the case of the toilet the velocity of the water is down and the omega of the Earth is horizontal (East West), so v cross omega is perpendicular and points North-South in the northern hemisphere.

Originally Posted by Another site

Selecting gyroscopes requires an understanding of angular rate measurement techniques.

Optical gyros permit the reflection of a laser ray many times within an enclosure. If the enclosure rotates, the duration between the moment of laser emittance and eventual reception differs. With ring laser gyros (RLF), the laser reflection is achieved with mirrors inside the enclosure. With fiber optic gyros (FOG), the laser reflection is achieved with a coil of optical fiber.

Spinning mass gyros use a steadily-moving mass with a free-moving axis (gimbal). These gyroscopes are very fragile and require regular maintenance. When a spinning mass gyro is tilted, the gyroscopic effect causes precession – motion orthogonal to the direction tilt sense – along the axis of the rotating mass, indicating that the angle has moved. Because mechanical constraints cause numerous error factors, the axis of a spinning mass gyro is usually fixed with springs. Spring tension is proportional to the precession speed.

Vibrating gyros use micro-electro-mechanical system (MEMS) technology and a vibrating, quartz tuning-fork to measure Coriolis force. When rotated, a vibrating element (vibrating resonator) is subjected to the Coriolis Effect, causing secondary vibration orthogonal to the original vibrating direction. By sensing the secondary vibration, the gyro can detect the rate of turn.