VIBRATION RECTIFICATION ERROR CORRECTION CIRCUIT, PHYSICAL QUANTITY SENSOR MODULE, STRUCTURE MONITORING DEVICE, AND CORRECTION VALUE ADJUSTMENT METHOD OF VIBRATION RECTIFICATION ERROR CORRECTION CIRCUIT

• US 20190331491A1
• Filed: 04/26/2019
• Published: 10/31/2019
• Est. Priority Date: 04/27/2018
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: TODOROKIHARA, Masayoshi, SATO, Kenta
• Granted Patent: US 11,808,572 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 19/5614 Signal processing
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01H 17/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups see provisionally also G01H1/00
• CPC Class Codes: G01H 3/005 Testing or calibrating of detectors covered by the subgroups of G01H3/00 calibrating geophysical instruments, e.g. seismic receivers G01V13/00
• CPC Class Codes: G01P 15/10 by vibratory strings
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/132 with electromagnetic counterbalancing means
• CPC Class Codes: G01P 2015/0822 for defining out-of-plane movement of the mass
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A vibration rectification error correction circuit includes a first correction circuit that obtains a digital value based on a signal to be measured output from a sensor element configured to measure a physical quantity and corrects a vibration rectification error of the digital value by a correction function based on a product of values obtained by biasing the digital value.

Claims

1. A vibration rectification error correction circuit comprising:

a first correction circuit that obtains a digital value based on a signal to be measured output from a sensor element configured to measure a physical quantity and corrects a vibration rectification error of the digital value by a correction function based on a product of values obtained by biasing the digital value.

2. The vibration rectification error correction circuit according to claim 1, wherein

the correction function is a quadratic function, and

a quadratic coefficient of the quadratic function is 1.

3. The vibration rectification error correction circuit according to claim 1, further comprising:

a frequency delta sigma modulation circuit; and

a second correction circuit that includes a first filter circuit and a second filter circuit and corrects the vibration rectification error based on a filter characteristic of the first filter circuit and a filter characteristic of the second filter circuit, wherein

the frequency delta sigma modulation circuit generates a frequency delta sigma modulation signal obtained by performing frequency delta sigma modulation on a reference signal using an operation signal based on the signal to be measured,

the first filter circuit is provided on an output side of the frequency delta sigma modulation circuit and operates in synchronization with the operation signal,

the second filter circuit is provided on an output side of the first filter circuit and operates in synchronization with the reference signal, and

a signal output from the second filter circuit is input to the first correction circuit.

4. A physical quantity sensor module comprising:

the vibration rectification error correction circuit according to claim 1; and

the sensor element.

5. A physical quantity sensor module comprising:

the vibration rectification error correction circuit according to claim 3; and

the sensor element.

6. The physical quantity sensor module according to claim 4, wherein

the sensor element measures at least one of mass, acceleration, angular velocity, angular acceleration, electrostatic capacitance, and temperature as a physical quantity.

7. The physical quantity sensor module according to claim 5, wherein

the sensor element measures at least one of mass, acceleration, angular velocity, angular acceleration, electrostatic capacitance, and temperature as a physical quantity.

8. A structure monitoring device comprising:

the physical quantity sensor module according to claim 5;

a receiver receiving a measurement signal from the physical quantity sensor module attached to a structure; and

a calculator calculating an inclination angle of the structure based on a signal output from the receiver.

9. A correction value adjustment method of a vibration rectification error correction circuit, the circuit including:

a first correction circuit that obtains a digital value based on a signal to be measured output from a sensor element configured to measure a physical quantity and corrects a vibration rectification error of the digital value by a correction function based on a product of values obtained by biasing the digital value,

a frequency delta sigma modulation circuit for generating a frequency delta sigma modulation signal obtained by performing frequency delta sigma modulation on a reference signal using an operation signal based on the signal to be measured, and

a second correction circuit that includes a first filter circuit provided on an output side of the frequency delta sigma modulation circuit and operating in synchronization with the operation signal and a second filter circuit provided on an output side of the first filter circuit and operating in synchronization with the reference signal to output a signal to the first correction circuit, and corrects the vibration rectification error based on a filter characteristic of the first filter circuit and a filter characteristic of the second filter circuit, the method comprising;

adjusting a correction value of the correction function of the first correction circuit; and

adjusting the filter characteristic of the first filter circuit and the filter characteristic of the second filter circuit of the second correction circuit, wherein

the adjusting of the correction value is performed before the adjusting of the filter characteristic.