Adaptive circuits and methods for reducing vibration or shock induced errors in inertial sensors

Abstract

Adaptive circuits (104,114,118,128,140,160,168) and methods for reducing vibration-induced bias errors in inertial sensors are disclosed. An adaptive circuit for reducing vibration or shock induced errors in an inertial sensor having a proof mass (12,14) and sense electrode (74,76) may include a sense bias voltage source (90), a charge amplifier (80), a means for detecting and/or anticipating an external vibration or shock on the inertial sensor, and a means for selectively dampening the proof masses and/or adjusting the gain sensitivity of the charge amplifier in response to an external vibration or shock on the inertial sensor. A dampening resistive element (108,122) may be provided to dampen the proof mass motion in response to an external vibration or shock on the inertial sensor. Alternatively, or in addition, the gain sensitivity of the rate signal (82,146,150) outputted by the charge amplifier can be adjusted in response to an external vibration or shock on the inertial sensor. During operation, the dampening and/or gain sensitivity can be adjusted to prevent signal saturation or clipping from occurring in the sense electronics, allowing the inertial sensor to continue functioning during periods of vibration or shock.