A quadrature compensation method for mems gyroscopes and a gyroscope sensor

A method for quadrature compensation for a gyroscope sensor,

• said gyroscope sensor comprising:
• a total inertial mass comprising a first inertial mass and a second inertial mass physically attached to each other a first inertial mass and a second inertial mass physically attached to each other, each of said first and second inertial mass being arranged spaced apart from and facing a respective first and a respective second electrode, wherein a rotation of said first inertial mass about a detection axis of said gyroscope sensor, said detection axis being perpendicular to said sensitivity axis and said rotation being caused by the coriolis force when said gyroscope sensor is subjected to a rotation about said sensitivity axis, results in a positive change of the capacitance between said total inertial mass and one of said first and said second electrode and a negative change of the capacitance between said total inertial mass and the other one of said first and said second electrode;
• a first drive structure comprising:
• a first and a second correction electrode arranged side by side and separated by a gap, and arranged on the same side of said first inertial mass as the first electrode and facing in the same direction;
• and
• a first displaceable drive frame being displaceable relative to both said first and second correction electrodes and the first inertial mass and physically attached to the first inertial mass via a first coupling member, said drive frame comprising:
• a first elongated correction member, said first elongated correction member arranged spatially and electrically separated from the first and the second correction electrode, arranged such that an overlap between the first elongated correction member with the gap and each of the first and the second correction electrode is variable,
• wherein said method comprises the steps of:
• causing said drive frame to move in a lateral direction, thereby causing said first inertial mass to oscillate in a rotational motion about an excitation axis perpendicular to said detection axis and to said sensitivity axis;
• detecting a quadrature offset by detecting a variation of the capacitance between said total inertial mass and one of said first and said second electrode corresponding to a motion of said first inertial mass about said detection axis, said variation in capacitance being in phase with said rotational motion of first inertial mass about said excitation axis;
• and
• applying a voltage across said first and said second correction electrode based on said detected quadrature offset, thereby subjecting said first elongated correction member to an electrostatic force, thereby rotating said drive frame about said detection axis and thereby also rotating said first inertial mass about said detection axis.