Patent ID: 6575029
Filing Date: 2003-06-10
Classification: G01P,G01V

Abstract:
An accelerometer comprisinga magnet means that produces a magnetic field; a proof mass that is suspended by a spring within said magnetic field and that tends to move in response to an applied acceleration force; position sensor means for said proof mass and for producing a position signal representative of the position of said proof mass; a reaction coil adjacent said proof mass and within said magnetic field; an internal feedback loop that receives said position signal, that provides a feedback signal related to movement tendency of said proof mass, that delivers said feedback signal to said reaction coil to maintain said proof mass stationary and that generates in said reaction coil a current signal which is representative of an acceleration force applied to said proof mass; an external feedback loop that receives said current signal, that may receive a second corresponding current signal from a second opposing accelerometer which is paired with said accelerometer, and that combines and processes said so received current signals, and that produces a corrective signal; a relatively small electromagnet means associated with said magnet means for receiving said corrective signal and for responsively adjusting said accelerometer to correct for mismatches between said accelerometer and said second accelerometer; thereby to adjust an acceleration scale factor and permit said internal feedback loop to provide second order compensation to said proof mass and the stiffness of said spring.