Detection device, sensor, electronic apparatus and moving object

• US 10,113,874 B2
• Filed: 12/04/2014
• Issued: 10/30/2018
• Est. Priority Date: 12/05/2013
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Nakajima, Katsuhito, Maki, Katsuhiko
• Primary Examiner(s): Pham, Ly D
• Application Number:
  US14/560,376
• Publication Number:
  US 20150160011A1
• Time in Patent Office: 1,426 Days
• Field of Search: 702 56
• CPC Class Codes: G01C 19/00 Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 19/5726 Signal processing
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719

Abstract

A detection device includes: a drive circuit that receives a feedback signal from a vibrator and drives the vibrator; a detection circuit that performs detection based on a signal from the vibrator and outputs detection data; and a digital signal processing unit that performs digital filtering for the detection data from the detection circuit. The digital signal processing unit performs band elimination filtering for attenuating a component of a detuning frequency Δf=|fd−fs| corresponding to a difference between a drive side resonance frequency fd and a detection side resonance frequency fs of the vibrator for the detection data.

Claims

1. A detection device comprising:

a drive circuit that receives a feedback signal from a vibrator and drives the vibrator;

a detection circuit that performs detection based on a signal from the vibrator and outputs detection data; and

a digital signal processing unit that performs digital filtering for the detection data from the detection circuit, the digital signal processing unit including a band elimination filtering circuit,

the band elimination filtering circuit comprising;

a multiplier;

a multiplication result register connected to the multiplier and configured to store multiplication result data of the multiplier;

an adder;

a first addition result register and a second addition result register connected to the adder and configured to store selectively addition result data of the adder;

a fifth selector connected to the multiplier and the adder and configured to select any one of the multiplication result data of the multiplier and the addition result data of the adder, and output;

an output register connected to the fifth selector and configured to store the output data of the fifth selector;

a first selector connected to an input and to the output register and configured to select any one of input data and the data of the output register, and output to the multiplier;

a second selector connected to a storage unit and configured to select any one of a plurality of filter coefficients stored in the storage unit, and output to the multiplier;

a third selector connected to the input and the multiplication result register and configured to select any one of the input data and data stored in the multiplication result register, and output to the adder; and

a fourth selector connected to the input, the first addition result register, and the second addition result register and configured to select any one of the input data and data stored in the first addition result register and the second addition result register, and output to the adder;

wherein the digital signal processing unit performs band elimination filtering, by way of the band elimination filtering unit, for attenuating a component of a detuning frequency Δ

f=|fd−

fs| corresponding to a difference between a drive side resonance frequency fd and a detection side resonance frequency fs of the vibrator for the detection data.

2. The detection device according to claim 1,

wherein the storage unit stores information on a plurality of filter coefficients so that each filter coefficient corresponds to a respective vibrator.

3. The detection device according to claim 1, the digital signal processing unit further comprising a band limit low pass filter unit, an input of the band elimination filtering unit directly connected to an output of the band limit low pass filter unit,

wherein the digital signal processing unit performs band limit low pass filtering, by way of the band limit low pass filter unit, in which a cutoff frequency is variable, and

when a variable range of the cutoff frequency of the low pass filter is represented as fca to fcb and a center frequency of the band elimination filter is represented as fm, a relationship of fca<

fm<

fcb is satisfied.

4. The detection device according to claim 1, further comprising:

an interface unit that outputs output data to the outside being asynchronous to an output timing of the detection data of the digital signal processing unit.

5. A sensor comprising:

the detection device according to claim 1; and

the vibrator.

6. A sensor comprising:

the detection device according to claim 1; and

the vibrator.

7. An electronic apparatus comprising the detection device according to claim 1.

8. A moving object comprising the detection device according to claim 1.