APPARATUS AND METHOD FOR CORRECTING GYRO SENSOR

• US 20160061628A1
• Filed: 04/06/2015
• Published: 03/03/2016
• Est. Priority Date: 09/01/2014
• Status: Abandoned Application

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: KIM, Kyung Rin, HWANG, Byoung Won, KIM, Chang Hyun
• Application Number:
  US14/679,245
• Publication Number:
  US 20160061628A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719

Abstract

There is provided an apparatus for correcting a gyro sensor, including: a driving circuit using a driving displacement signal from the gyro sensor and a reference voltage to output a demodulated signal; a correction circuit determining whether a duty ratio of the demodulated signal is distorted and performing a correction to converge the duty ratio of the demodulated signal to a preset target value if it is determined that the duty ratio of the demodulated signal is distorted; and a sensing circuit performing a demodulation process of a sensing signal from the gyro sensor using the demodulated signal to output a gyro signal, whereby it is possible to accurately detect the gyro signal so as to assure reliability of the gyro sensor.

Claims

1. An apparatus for correcting a gyro sensor, comprising:

a driving circuit using a driving displacement signal from the gyro sensor and a reference voltage to output a demodulated signal;

a correction circuit determining whether a duty ratio of the demodulated signal is distorted and performing a correction to converge the duty ratio of the demodulated signal to a preset target value if it is determined that the duty ratio of the demodulated signal is distorted; and

a sensing circuit performing a demodulation process of a sensing signal from the gyro sensor using the demodulated signal to output a gyro signal.

2. The apparatus of claim 1, wherein the driving circuit includes:

a first charge amplifier converting the driving displacement signal output from the gyro sensor into a voltage signal form;

a phase shifter shifting a phase of an output signal from the first charge amplifier;

a comparator comparing an output signal from the phase shifter with the reference voltage to generate the demodulated signal; and

a pulse generator generating a driving signal based on the demodulated signal.

3. The apparatus of claim 2, wherein the reference voltage varies by a control of the correction circuit when the distortion of the duty ratio of the demodulated signal occurs.

4. The apparatus of claim 1, wherein the correction circuit includes:

a processor integrating the demodulated signal received from the driving circuit to determine whether the duty ratio of the demodulated signal is distorted and generating a digital control signal depending on the integration result; and

a reference voltage controller receiving the digital control signal to adjust the reference voltage.

5. The apparatus of claim 4, wherein the processor includes:

a clock oscillator generating a clock signal;

an integrator performing an integration process using the clock signal to calculate an integral value of the demodulated signal;

a distortion determiner comparing the integral value with a preset reference value and determining that the duty ratio of the demodulated signal is distorted when the integral value is different from the reference value; and

a digital controller calculating a correction value adjusting the reference voltage to make the integral value equal to the reference value and generating a digital control signal corresponding to the correction value.

6. The apparatus of claim 4, wherein the reference voltage controller includes:

a signal converter converting the digital control signal into an analog control signal; and

an analog controller adjusting the reference voltage based on the analog control signal to converge the duty ratio of the demodulated signal to the target value.

7. The apparatus of claim 6, wherein the signal converter is a digital to analog converter.

8. The apparatus of claim 1, wherein the sensing circuit includes:

a second charge amplifier converting the sensing signal output from the gyro sensor into a voltage signal form;

a demodulator performing a demodulation process of mixing an output signal from the second charge amplifier with the demodulated signal;

a low pass filter removing a high frequency component of an output signal from the demodulator; and

an analog to digital converter converting an output signal from the low pass filter into a digital signal value.

9. A method for correcting a gyro sensor, comprising:

a driving step of generating a demodulated signal based on a driving displacement signal of the gyro sensor and a reference voltage;

a correction step of determining whether a duty ratio of the demodulated signal is distorted and converging the duty ratio of the demodulated signal to a preset target value if it is determined that the duty ratio of the demodulated signal is distorted; and

a sensing step of detecting a gyro signal using a demodulation process of the demodulated signal and a sensing signal from the gyro sensor.

10. The method of claim 9, wherein the driving step includes:

a step of converting the driving displacement signal output from the gyro sensor into a voltage signal form;

a step of shifting a phase of the driving displacement signal in the voltage signal form;

a step of comparing the shifted driving displacement signal with the reference voltage to generate the demodulated signal; and

a step of generating a driving signal based on the demodulated signal.

11. The method of claim 9, wherein the correcting includes:

a digital correction step of integrating the demodulated signal to determine whether the duty ratio of the demodulated signal is distorted and generating a digital control signal depending on the integration result of the demodulated signal if it is determined that the distortion occurs; and

a reference voltage control step of adjusting the reference voltage depending on the digital control signal.

12. The method of claim 11, wherein the digital correction step includes:

a step of generating a clock signal;

a step of integrating the demodulated signal using the clock signal to calculate an integral value;

a distortion determination step of comparing the integral value with a preset reference value and determining that the duty ratio of the demodulated signal is distorted when the integral value is different from the reference value; and

a step of calculating a correction value adjusting the reference voltage to make the integral value equal to the reference value and generating a digital control signal corresponding to the correction value.

13. The method of claim 11, wherein the reference voltage control step includes:

a step of converting the digital control signal into an analog control signal; and

a step of adjusting the reference voltage based on the analog control signal to converge the duty ratio of the demodulated signal to the target value.

14. The method of claim 9, wherein the sensing includes:

a step of, by a second charge amplifier, converting the driving displacement signal output from the gyro sensor into a voltage signal form;

a step of mixing, by a demodulator, an output signal from the second charge amplifier with the demodulated signal;

a step of removing, by a low pass filter, a high frequency component of an output signal from the demodulator; and

a step of converting an output signal from the filter into a digital value.