Accelerometer and spherical sensor type measuring instrument
First Claim
1. An accelerometer, having a spherical mass part, of either single-crystal or polycrystalline silicon, which is levitated by electrostatic supporting forces, and a plurality of electrodes, having spherical inner surfaces, which are positioned symmetrically and so as to surround said spherical mass part.
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Accused Products
Abstract
An object is to provide an accelerometer or a spherical sensor-type measurement device, able to control by means of an active restraining control system a spherical mass part or a spherical sensor part. The accelerometer or spherical sensor-type measurement device has a spherical mass part, which is levitated by electrostatic supporting forces, and electrodes positioned so as to surround the spherical mass part and which have spherical inner surfaces; the above electrodes include a plurality of electrostatic supporting electrodes, positioned symmetrically with respect to the spherical mass part, and a displacement detection electrode, positioned between the electrostatic supporting electrodes.
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Citations
18 Claims
- 1. An accelerometer, having a spherical mass part, of either single-crystal or polycrystalline silicon, which is levitated by electrostatic supporting forces, and a plurality of electrodes, having spherical inner surfaces, which are positioned symmetrically and so as to surround said spherical mass part.
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9. An accelerometer, comprising:
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a spherical mass part, which is levitated by means of electrostatic supporting forces;
electrostatic supporting electrodes, positioned so as to surround the spherical mass part, and a displacement detection electrode, positioned between the electrostatic supporting electrodes;
a control operation part, which applies to said electrostatic supporting electrodes a control DC voltage in order to generate said electrostatic supporting forces;
a displacement detection system, which applies an AC voltage for displacement detection, superposed on said control DC voltage, to said electrostatic supporting electrodes, and which detects displacement detection currents flowing in said displacement detection electrode and generates displacement detection voltage signals which instruct the displacement of said spherical mass part; and
,an acceleration output operation part, which inputs the output signals of said control operation part and operates the acceleration output;
being characterized in that said control operation part inputs said displacement detection voltage signals output by said displacement detection circuit and operates corrections to said control DC voltages such that the displacement of said spherical mass part becomes zero, for feedback to said control DC voltages.- View Dependent Claims (10, 11, 12, 13, 14, 15)
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12. The accelerometer according to claim 9, being characterized in that each of said electrostatic supporting electrodes comprises one pair of electrode parts, and said control DC voltages applied to a pair of electrode parts are of the same magnitude and of opposite polarity.
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13. The accelerometer according to claim 9, being characterized in that said control operation part comprises a displacement operation part, which operates the displacement of said spherical mass part;
- a PID operation part, which operates the force to be applied to said spherical mass part; and
a control voltage operation part, which operates corrections to said control DC voltages.
- a PID operation part, which operates the force to be applied to said spherical mass part; and
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14. The accelerometer according to claim 13, being characterized in that said acceleration output operation part is configured so as to input the output signal of said PID operation part and operate the acceleration output.
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15. The accelerometer according to claim 9, being characterized in that said spherical mass part consists of single-crystal or polycrystalline silicon.
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16. A spherical sensor-type measurement device, comprising a spherical mass part which functions as an inertial force sensor;
- a spherical shell-shape enclosure part which surrounds said spherical mass part;
a displacement detection device which detects displacements of said spherical mass part;
end an electrode positioned in said enclosure part, and having a spherical-shape inner surface. - View Dependent Claims (17, 18)
- a spherical shell-shape enclosure part which surrounds said spherical mass part;
Specification