Physical quantity sensor device, and inclinometer, inertia measurement device, structure monitoring device, and moving object using physical quantity sensor device

Patent metadata

Field	Value
Publication number	US-10989729-B2
Application number	US-201916296326-A
Country	US
Kind code	B2
Filing date	Mar 8, 2019
Priority date	Mar 9, 2018
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

A physical quantity sensor device includes a physical quantity sensor and a storage. The storage stores a first constant used as a constant of each term in an approximate polynomial to obtain a first secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a first temperature region less than the first boundary temperature, and a second constant used as a constant of each term in the approximate polynomial to obtain a second secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a second temperature region equal to or greater than the first boundary temperature.

First claim

What is claimed is:

1. A physical quantity sensor device comprising:
a physical quantity sensor; and
a storage,
wherein the storage stores,
when a temperature at which an absolute value of an error between an actual frequency temperature characteristic measured by using the physical quantity sensor and a primary frequency temperature characteristic approximated to the actual frequency temperature characteristic over an entire operating temperature range by a single approximate polynomial using a predetermined constant becomes a maximum value is set as a first boundary temperature,
a first constant used as a constant of each term in the approximate polynomial to obtain a first secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a first temperature region less than the first boundary temperature, and
a second constant used as a constant of each term in the approximate polynomial to obtain a second secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a second temperature region equal to or greater than the first boundary temperature.

2. The physical quantity sensor device according to claim 1 ,
wherein the maximum value is actual data obtained for a plurality of temperatures in the entire operating temperature range of any one of the actual frequency temperature characteristics created based on the actual data.

3. The physical quantity sensor device according to claim 1 ,
wherein the maximum value is a value interpolated between two pieces of actual data among the actual frequency temperature characteristics created based on actual data obtained for a plurality of temperatures in the entire operation temperature range.

4. The physical quantity sensor device according to claim 1 ,
wherein the storage stores, instead of the first constant,
when a temperature at which the error between the actual frequency temperature characteristic and the primary frequency temperature characteristic becomes a maximum value or a minimum value is set as a second boundary temperature in the first temperature region,
a third constant used as a constant of each term in the approximate polynomial to obtain a third secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a third temperature region less than the second boundary temperature, and
a fourth constant used as a constant of each term in the approximate polynomial to obtain a fourth secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a fourth temperature region equal to or greater than the second boundary temperature and less than the first boundary temperature.

5. The physical quantity sensor device according to claim 1 ,
wherein the storage stores, instead of the second constant,
when a temperature at which the error between the actual frequency temperature characteristic and the primary frequency temperature characteristic becomes a maximum value or a minimum value is set as a third boundary temperature in the second temperature region,
a fifth constant used as a constant of each term in the approximate polynomial to obtain a fifth secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a fifth temperature region equal to or greater than the first boundary temperature and less than the third boundary temperature, and
a sixth constant used as a constant of each term in the approximate polynomial to obtain a sixth secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a sixth temperature region equal to or greater than the third boundary temperature.

6. The physical quantity sensor device according to claim 1 ,
wherein the actual frequency temperature characteristic includes a dip in which the frequency locally decreases at the first boundary temperature.

7. The physical quantity sensor device according to claim 5 ,
wherein the actual frequency temperature characteristic includes a first dip locally decreasing at the first boundary temperature, and
a second dip locally decreasing at the second boundary temperature or the third boundary temperature.

8. The physical quantity sensor device according to claim 1 ,
wherein the storage stores, instead of the first constant,
when a temperature at which the error between the actual frequency temperature characteristic and the first secondary frequency temperature characteristic becomes a maximum value or a minimum value is set as a second boundary temperature in the first temperature region,
a third constant used as a constant of each term in the approximate polynomial to obtain a first tertiary frequency temperature characteristic that minimizes an absolute value of the error between the actual frequency temperature characteristic and the first secondary frequency temperature characteristic in a third temperature region less than the second boundary temperature, and
a fourth constant used as a constant of each term in the approximate polynomial to obtain a second tertiary frequency temperature characteristic that minimizes an absolute value of the error between the actual frequency temperature characteristic and the second secondary frequency temperature characteristic in a fourth temperature region equal to or greater than the second boundary temperature and less than the first boundary temperature.

9. The physical quantity sensor device according to claim 1 ,
wherein the storage stores, instead of the second constant,
when a temperature at which the error between the actual frequency temperature characteristic and the second secondary frequency temperature characteristic becomes a maximum value or a minimum value is set as a third boundary temperature in the second temperature region,
a fifth constant used as a constant of each term in the approximate polynomial to obtain a third tertiary frequency temperature characteristic that minimizes an absolute value of the error between the actual frequency temperature characteristic and the second secondary frequency temperature characteristic in a fifth temperature region equal to or greater than the first boundary temperature and less than the third boundary temperature, and
a sixth constant used as a constant of each term in the approximate polynomial to obtain a fourth tertiary frequency temperature characteristic that minimizes an absolute value of the error between the actual frequency temperature characteristic and the second secondary frequency temperature characteristic in a sixth temperature region equal to or greater than the third boundary temperature.

10. The physical quantity sensor device according to claim 1 ,
wherein the first constant and the second constant differ from each other in at least one of (N+1) constants when the single approximate polynomial is an N-th order polynomial (N is an integer of 2 or more).

11. The physical quantity sensor device according to claim 1 ,
further comprising a circuit board is provided,
wherein three physical quantity sensors are provided, and
the three physical quantity sensors may be mounted on the circuit board so that each of detection axes of the three physical quantity sensors is aligned with each of three axes orthogonal to each other.

12. The physical quantity sensor device according to claim 1 ,
wherein the physical quantity sensor includes
a base,
a movable portion,
a constricted portion that is disposed between the base and the movable portion and connects the base and the movable portion, a

Assignees

• Seiko Epson Corp

Inventors

• Sato Kenta

Classifications

• G01C19/5607

  using vibrating tuning forks (double-ended tuning forks using planar vibrating masses suspended at opposite ends G01C19/5719) · CPC title

• G01C9/02 Primary

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• G01P15/18

  in two or more dimensions · CPC title

• G01P21/00

  Testing or calibrating of apparatus or devices covered by the preceding groups · CPC title

• G01C21/165

  combined with non-inertial navigation instruments · CPC title