An accelerometer comprising: a frame; one or more proof masses suspended from the frame by one or more flexures and movable relative to the frame along a sensing axis; a first resonant element fixed between an anchor on the frame and the one or more proof masses, and extending from the anchor to the one or more proof masses along the sensing axis; a second resonant element fixed between the anchor and the one or more proof masses and extending from the anchor to the one or more proof masses along the sensing axis in a opposite direction to the first resonant element.

An acceleration-measuring sensor assembly includes an accelerometer subassembly with three measurement axes, mounted in a housing equipped with securing elements, and configured to determine an acceleration along a principal axis A, the assembly comprising: a single-axis principal accelerometer with a seismic mass moving in a straight line along a principal axis A, measuring acceleration along the principal axis A which is misaligned with respect to a reference axis Y by at most 50 mrad, a secondary accelerometer having at least two measurement axes and measuring respectively along two axes X and Z which with the reference axis Y form a direct orthonormal trihedron (O, X, Y, Z), the measurement precision of the two-axis accelerometer along each of its axes being at least ten times inferior to the measurement precision of the single-axis accelerometer, and an electronic processing unit configured to calculate a compensated acceleration S.

The structure enables two-directional sensing of accelerations with compact component dimensions and with minimal cross-axis sensitivity. The rotation mass includes a first frame and a second frame. In one sense direction, the structure employs a combined proof mass of the first frame and the second frame, which improves the signal to noise level achievable with said device dimensions. In the other sense direction, a detection structure with at least two sensing elements is used to detect displacements of the proof mass of the second frame. Due to the specific internal configuration of the detection structure, signal contributions of the sensing elements in the one direction cancel each other.

A MEMS sensor may include multiple sense electrodes located relative to respective portions of one or more proof masses of a MEMS layer of the sensor. Individual sense electrodes are capable of individual calibration within the drive and/or sense path for the sense electrode. A distance between each individual sense electrode relative to a proof mass is determined for the at-rest state of the sensor. Calibration values are determined based on these distances, and individual drive and/or sense signals associated with each sense electrode are modified to adjust for changes in distance, such as are caused by shifting, tilting, or bending of the MEMS layer or substrate.

The structure enables two-directional sensing of accelerations with compact component dimensions and with minimal cross-axis sensitivity. The rotation mass includes a first frame and a second frame. In one sense direction, the structure employs a combined proof mass of the first frame and the second frame, which improves the signal to noise level achievable with said device dimensions. In the other sense direction, a detection structure with at least two sensing elements is used to detect displacements of the proof mass of the second frame. Due to the specific internal configuration of the detection structure, signal contributions of the sensing elements in the one direction cancel each other.

This document discusses among other things apparatus and methods for a proof mass including split z-axis portions. An example proof mass can include a center portion configured to anchor the proof-mass to an adjacent layer, a first z-axis portion configure to rotate about a first axis using a first hinge, the first axis parallel to an x-y plane orthogonal to a z-axis, a second z-axis portion configure to rotate about a second axis using a second hinge, the second axis parallel to the x-y plane, wherein the first z-axis portion is configured to rotate independent of the second z-axis portion.

A MEMS sensor may include multiple sense electrodes located relative to respective portions of one or more proof masses of a MEMS layer of the sensor. Individual sense electrodes are capable of individual calibration within the drive and/or sense path for the sense electrode. A distance between each individual sense electrode relative to a proof mass is determined for the at-rest state of the sensor. Calibration values are determined based on these distances, and individual drive and/or sense signals associated with each sense electrode are modified to adjust for changes in distance, such as are caused by shifting, tilting, or bending of the MEMS layer or substrate.

An acceleration-measuring sensor assembly includes an accelerometer subassembly with three measurement axes, mounted in a housing equipped with securing elements, and configured to determine an acceleration along a principal axis A, the assembly comprising: a single-axis principal accelerometer with a seismic mass moving in a straight line along a principal axis A, measuring acceleration along the principal axis A which is misaligned with respect to a reference axis Y by at most 50 mrad, a secondary accelerometer having at least two measurement axes and measuring respectively along two axes X and Z which with the reference axis Y form a direct orthonormal trihedron (O, X, Y, Z), the measurement precision of the two-axis accelerometer along each of its axes being at least ten times inferior to the measurement precision of the single-axis accelerometer, and an electronic processing unit configured to calculate a compensated acceleration S.