Acceleration-measuring sensor assembly comprising an accelerometer subassembly with three measurement axes, and a seismic mass moving in a straight line along a principal axis A, which assembly is mounted in a housing and configured to determine an acceleration along a measurement axis Y

An acceleration-measuring sensor assembly comprising an accelerometer subassembly with three measurement axes, mounted in a housing equipped with securing elements, and configured to determine an acceleration along a measurement axis OY, the assembly comprising:

• a single-axis principal accelerometer with a seismic mass moving in a straight line along a sensitive principal axis A, insensitive to transverse accelerations, measuring acceleration along the sensitive principal axis A which is misaligned with respect to the measurement axis OY 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 measurement 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 principal single-axis accelerometer, and
• an electronic processing unit configured to perform calculations and at output deliver an acceleration S compensated for by means of the following relationship:
• S
• =
• S
• p
• ⁢
• r
• ⁢
• A
• -
• μ
• C
• ⁢
• a
• ⁢
• l
• ⁢
• Z
• ·
• S
• s
• ⁢
• e
• ⁢
• c
• ⁢
• X
• +
• μ
• C
• ⁢
• a
• ⁢
• l
• ⁢
• X
• ·
• S
• s
• ⁢
• e
• ⁢
• c
• ⁢
• Z
• SprAμCalX, μCalZ SsecX, SsecZ wherein:
• SprAμCalX, μCalZ SsecX, SSecZ represents the acceleration measurement along the sensitive principal axis A;
• SprAμCalX, μCalZ SsecX, SsecZ represent the parameters compensating respectively for the alignments of axes X, Z of the sensor as a whole, these being dimensionless quantities, measured after assembly of the sensor as a whole;
• and
• SprAμCalX, μCalZ SsecX, SsecZ represent the compensation acceleration along the transverse axis X and along the transverse axis Z, respectively.