Transducer element for measuring angular and linear acceleration
First Claim
1. Transducer element for measuring angular and linear acceleration comprising:
- a pair of electromechanical beams extending along a first axis in a common plane and cantileverly mounted to at least one fixing element substantially at a second axis perpendicular to said plane of said beams and symmetrical with respect to a third axis orthogonal to said first and second axis;
means for fixedly mounting said fixing element to an object whose angular acceleration about said third axis and linear acceleration along said second axis are to be measured;
each of said beams comprising piezoelectric material having a specific electrical polarization direction;
first means for connecting electrical output signals generated by the flexure of the beams to a signal processing facility as a sum of the output signals if the material of the beams have different electrical polarization directions and as a difference of the output signals if the electrical polarization directions are the same, to produce a measuring signal representing the angular acceleration of the object about the third axis; and
second means for connecting said output signals to a signal processing facility as a sum of the output signals from the beams if the material of the beams have the same electrical polarization directions and as a difference of the output signal if the electrical polarization directions are dissimilar, to produce a measuring signal for the linear acceleration along said second axis at right angles to the plane of the beams.
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Accused Products
Abstract
A transducer element for measuring angular and linear accelerations including a pair of electromechanically reacting oscillating beams held symmetrical to a main axis y on a base plate by fixing elements. The electrical output signals proportional to the flexure of the beams under rotation about the y axis are provided to a signal processing circuit, which is designed so that with similar or dissimilar polarity of the oscillating beams a summing amplifier determines the linear acceleration along the z axis and a differential amplifier the angular acceleration about the y axis. The oscillating beams may be piezoelectric bending elements, or bending elements coated with piezoresistive semiconductors, or else provided with strain gauges.
28 Citations
5 Claims
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1. Transducer element for measuring angular and linear acceleration comprising:
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a pair of electromechanical beams extending along a first axis in a common plane and cantileverly mounted to at least one fixing element substantially at a second axis perpendicular to said plane of said beams and symmetrical with respect to a third axis orthogonal to said first and second axis; means for fixedly mounting said fixing element to an object whose angular acceleration about said third axis and linear acceleration along said second axis are to be measured; each of said beams comprising piezoelectric material having a specific electrical polarization direction; first means for connecting electrical output signals generated by the flexure of the beams to a signal processing facility as a sum of the output signals if the material of the beams have different electrical polarization directions and as a difference of the output signals if the electrical polarization directions are the same, to produce a measuring signal representing the angular acceleration of the object about the third axis; and second means for connecting said output signals to a signal processing facility as a sum of the output signals from the beams if the material of the beams have the same electrical polarization directions and as a difference of the output signal if the electrical polarization directions are dissimilar, to produce a measuring signal for the linear acceleration along said second axis at right angles to the plane of the beams. - View Dependent Claims (2, 3, 4)
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5. An accelerometer for measuring angular and linear acceleration comprising:
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a housing having first, second and third orthogonal axes; at least one transducer element having a pair of electromechanical beams extending along said first axis in a common plane and cantileverly mounted to at least one fixing element substantially at said second axis perpendicular to said plane of said beams and symmetrical with respect to said third axis orthogonal to said first and second axis, each of said beams comprising piezoelectric material having a specific electrical polarization direction; means for fixedly mounting said fixing element to said housing along said second axis; means for fixedly mounting said housing to an object whose angular acceleration about said third axis and linear acceleration about said second axis are to be measured; and signal processing means in said housing for receiving electrical output signal generated by the flexure of the beams, for adding said output signals if the material of the beams have different electrical polarization directions and subtracting the output signals if the electrical polarization directions are the same to produce an angular acceleration measuring signal about said third axis, and for adding said output signals if the material of said beams have the same electrical polarization directions and subtracting said output signals if the electrical polarization directions are different to produce a linear acceleration measuring signal along said second axis.
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Specification