What is the definition of Coriolis effect?
The Coriolis effect is the apparent deflection caused to a moving object caused by the Earth’s rotation. In a Coriolis effect gyroscope, an oscillating proof mass is used that creates a secondary vibration when the gyro is rotated due to the Coriolis effect on the proof mass. The secondary vibration is measured to determine the rate of rotation and resulting angular change.
Image depicts the operation of a simple MEMS Coriolis effect gyroscope.
- The springs (A) hold the proof mass (B) in position within the inner frame (C), creating the drive axis.
- The inner frame is isolated from the outer frame (D) using springs (E) set at 90 ° to the drive axis, creating the sense axis.
- The inner frame has several protruding fingers (i).
- The fixed electrodes (ii) make up differential capacitors, with a protruding finger from the inner frame between the capacitor electrodes.
During rotation, the Coriolis effect causes movement of the proof mass / inner frame against the direction of rotation that results in a change in capacitance that is proportional to the rate of rotation.
