Plane Sensor for Inertial Measurement
That's the reason for calling this thing a Plane Sensor.
At least three such plane sensors covering three independent planes in space are required in order to construct a complete inertial measurement unit (IMU) for three-dimensional space.
Usually one tries to make such a complete IMU as small as possible
and mount it as close as possible to the center of mass of the
object under measurement. (Note: From a mathematical point of view
it could be placed anywhere, but the closer it is located at the
center of mass the better it is especially for measuring the
A few Hardware Features:
Another thing is drift under dynamic conditions that includes things like frequency response of the sensors etc. That's a little bit difficult to determine in practice, because one needs special mechanical test equipment in order to generate deterministic mechanical motions.
What has been observed so far from the digital sample streams is a precision of around 12 bits for both gyroscope and accelerometer under static conditions. The lower 4 bits appear to be just white noise.
Then a couple of twins (at least two, but very likely three more) will have to be made with almost no change in architecture and sensor types. They will be used in their targeted application test bed for higher-level evaluation and testing porposes.
It is planned to do a redesign of these plane sensors some day with state-of-the-art technology in order to make them smaller, lighter, and better. This counts especially for the gyroscope, which is a rather fat and heavy thing that eats a lot of current (around 50mA). Although there are already better gyroscopes available today (e.g. the ADXRS150 from Analog Devices), the decision was made to go with the current setup in order to get something working in hand.
Top Side View
Bottom Side View
Some historical Pictures of the Prototype for some basic Testing :-)