Offset detection and compensation for micromachined inertial sensors

An inertial sensor comprising:

• a resonator;
• an accelerometer for measuring a Coriolis acceleration signal in a Coriolis acceleration signal band of a Coriolis channel, wherein the at least one error source induces corresponding error signals in the Coriolis channel that are in-phase with the drive signal and include error signals that affect the Coriolis acceleration signal;
• a resonator driver configured to provide a modulated drive signal to the resonator, the modulated drive signal modulating the magnitude of the drive force applied to the resonator so as to modulate the magnitude of the at least one error source so as to induce corresponding modulated error signals in the Coriolis channel, wherein the error signals are modulated at a frequency outside of the Coriolis acceleration signal band;
• an offset detector configured to sense the modulated error signals in the Coriolis channel;
• and
• a servo configured to provide at least one compensating signal responsive to the sensed modulated error signals to substantially cancel errors introduced by the at least one error source that affect the Coriolis acceleration signal.

A controller for detecting at least one error source relating to the magnitude of a drive signal applied to a resonator of an inertial sensor including the resonator and an accelerometer for measuring a Coriolis acceleration signal in a Coriolis acceleration signal band of a Coriolis channel, wherein the at least one error source induces corresponding error signals in the Coriolis channel that are in-phase with the drive signal and include error signals that affect the Coriolis acceleration signal, the controller comprising:

• a resonator driver configured to provide a modulated drive signal to the resonator, the modulated drive signal modulating the magnitude of the drive force applied to the resonator so as to modulate the magnitude of the at least one error source so as to induce corresponding modulated error signals in the Coriolis channel, wherein the error signals are modulated at a frequency outside of the Coriolis acceleration signal band;
• an offset detector configured to sense the modulated error signals in the Coriolis channel;
• and
• a servo configured to provide at least one compensating signal responsive to the sensed accelerometer signals to the inertial sensor to substantially cancel errors introduced by the at least one error source that affect the Coriolis acceleration signal.