Angular velocity sensor
First Claim
1. An angular velocity sensor for driving a vibrator in an X-axis direction and for detecting angular velocity based on vibrations caused by a Coriolis force generated in a Y-axis direction when said vibrator rotates about a Z-axis, said angular velocity sensor comprising:
- a vibrator outputting a left signal and a right signal;
a drive circuit connected to the vibrator;
a converter connected to the vibrator for digitizing said left signal and said right signal; and
an arithmetic operation unit for generating π
/2 phase shifted signals and computing and outputting a magnitude of the Coriolis force based on the left and right signals and on the π
/2 phase shifted signals.
1 Assignment
0 Petitions
Accused Products
Abstract
An angular velocity sensor includes a vibrator. A differential amplifier circuit outputs a differential signal including a Coriolis component from the vibrator. The differential signal is converted into a digital signal by an A/D converter. A Hilbert transformer shifts the differential signal by π/2. Two multipliers squares the original differential signal and the π/2-phase-shifted differential signal, respectively, and an adder computes the sum of the squares. A square root circuit computes the square root of the sum and outputs a magnitude signal proportional to Coriolis force.
14 Citations
17 Claims
-
1. An angular velocity sensor for driving a vibrator in an X-axis direction and for detecting angular velocity based on vibrations caused by a Coriolis force generated in a Y-axis direction when said vibrator rotates about a Z-axis, said angular velocity sensor comprising:
-
a vibrator outputting a left signal and a right signal;
a drive circuit connected to the vibrator;
a converter connected to the vibrator for digitizing said left signal and said right signal; and
an arithmetic operation unit for generating π
/2 phase shifted signals and computing and outputting a magnitude of the Coriolis force based on the left and right signals and on the π
/2 phase shifted signals.- View Dependent Claims (2, 3, 4, 5)
a differential amplifier circuit for determining a differential signal;
a phase circuit for shifting the phase of the differential signal by π
/2 to produce a π
/2 phase shifted differential signal;
a first multiplier circuit for squaring the differential signal;
a second multiplier circuit for squaring the π
/2 phase shifted differential signal generated by said phase circuit;
an adder circuit for adding the output of said first multiplier circuit and the output of said second multiplier circuit; and
a square root circuit for computing the square root of the output of said adder circuit.
-
-
3. An angular velocity circuit according to claim 2, wherein the phase circuit is a Hilbert transformer.
-
4. An angular velocity circuit according to claim 1, wherein said arithmetic operation unit comprises:
-
phase circuits for shifting the phase of the respective left and right signals by π
/2;
first multiplier circuits for squaring the respective original left and right signals;
second multiplier circuits for squaring the respective π
/2-phase-shifted left and right signals generated by said phase circuits;
a first adder circuit for adding the squared left signal obtained by the corresponding first multiplier circuit and the squared π
/2-phase-shifted left signal obtained by the corresponding second multiplier circuit;
a second adder circuit for adding the squared right signal obtained by the corresponding first multiplier circuit and the squared π
/2-phase-shifted right signal obtained by the corresponding second multiplier circuit;
a first square root circuit for computing the square root of the output of said first adder circuit;
a second square root circuit for computing the square root of the output of said second adder circuit; and
a subtracter circuit for computing the difference between the outputs of said first and said second square root circuits, dividing the difference in two, and outputting the halved difference.
-
-
5. An angular velocity circuit according to claim 4, wherein the phase circuits are Hilbert transformers.
-
6. An angular velocity sensor for driving a vibrator in an X-axis direction and for detecting angular velocity based on vibrations caused by a Coriolis force generated in a Y-axis direction when said vibrator rotates about a Z-axis, said angular velocity sensor comprising:
-
a vibrator outputting a left signal and a right signal;
a drive circuit connected to the vibrator; and
an arithmetic operation unit connected to the vibrator to obtain said left signal and said right signal, wherein the arithmetic operation unit computes and outputs the magnitude of the Coriolis force based on said left signal and said right signal. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
Specification