MEMS Annular Rotating Sensor (MARS)

"A MEMS rotating Annular Sensor (MARS) is proposed, which senses rotation velocities and accelerations in one discrete time sensor. The sensor system is sensitive to accelerations in all three local directions x, y, and z and rotational velocities in twoaxes. Differential capacitance measured at various points about the annulus permit a single MARS to measure accelerations in 3 degrees of freedom and rotational velocities in two, missing only the angular velocity about the local z axis. Two MARS systemscan be used for full three axis inertial measurements and provide redundancy in all three accelerations and two rotational velocity measures. With built-in processing capability, the MARS system results in an extremely small, low-cost yet robust inertialmeasurement system. Output of the MARS system will be in various digital serial formats.The MARS system has been designed to have four modes of operation: Storage, Start-up, Nominal operation and Shut-down. To enable reliable use, each mode is operated in a controlled operation enabling the device to handle very large g loads withoutfailure. Sensing rotational rates up to 500 degrees per second and accelerations up to 100 g are anticipated with the device. Existing inertial sensors require three rotational sensors and three acceleration sensors to obtain the information required for inertial sensing and control. By using the MARS system, these requirements are reduced to two MARS, the