EXTENDED-RANGE CLOSED-LOOP ACCELEROMETER

摘要

A microelectromechanical systems (MEMS) accelerometer with extended operational capabilities beyond a closed-loop saturation. The present invention combines the closed-loop feedback signal and the measured proof-mass position into a hybrid acceleration measurement, which effectively provides an operating range equal to the traditional closed-loop operating range plus the sensor's mechanical open-loop range.

主权项

1. An accelerometer device comprising:
a seesaw-mounted proof-mass; a plurality of capacitive sensors configured to sense position of the proof-mass; a plurality of driver devices configured to apply a force to the proof-mass based on a received feedback signal; a controller configured to
receive proof-mass position information from one or more of the sensors;generate the feedback signal based on the received proof-mass position information in order to keep the proof-mass at a null position;send the feedback signal to at least one of the driver devices; anddetermine whether closed-loop saturation has occurred based on the feedback signal;if closed-loop saturation has been determined to occur, determine an open-loop acceleration value based on the sensed proof-mass position information and determine an acceleration value based on the determined open-loop acceleration value and a maximum closed-loop acceleration value;if the closed-loop saturation has not been determined to occur, determine a closed-loop acceleration value based on the feedback signal; andoutput the determined acceleration value.