Electro-mechanical resonance loop

• US 8,912,856 B2
• Filed: 01/08/2013
• Issued: 12/16/2014
• Est. Priority Date: 01/08/2013
• Status: Active Grant

• Current Assignee: Hanking Electronics Hongkong Company Limited
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Cazzaniga, Gabriele, Forte, Federico, Prandi, Luciano
• Primary Examiner(s): Gannon, Levi
• Application Number:
  US13/736,591
• Publication Number:
  US 20140300425A1
• Time in Patent Office: 707 Days
• Field of Search: 735/033, 7350402-50404, 735/041.2, 735/041.4, 735/041.5, 331/154, 333/186, 333/188
• US Class Current: 331/154
• CPC Class Codes: G01C 19/5649 Signal processing
• CPC Class Codes: G01C 19/567 using the phase shift of a vibration node or antinode
• 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
• CPC Class Codes: G01P 15/097 by vibratory elements
• CPC Class Codes: G01P 15/14 by making use of gyroscopes gyroscopes per se G01C19/00
• CPC Class Codes: H03B 5/30 with frequency-determining element being electromechanical resonator

Abstract

The invention relates to a controller, and more particularly, to systems, devices and methods of controlling a sensor having a resonating mass. The controller includes: an analog-to-digital converter (ADC) unit for extracting a digitized sensor signal from the sensor signal; a phase controller for generating, based on the digitized sensor signal, a phase-controlled signal that is locked in phase with the digitized sensor signal; an amplitude controller for applying a gain to the digitized sensor signal to thereby generate an amplitude-adjusted signal; a modulator for modulating the amplitude-adjusted signal to thereby generate a modulated signal; and a phase shifter for shifting the phase of the modulated signal by 90 degrees. The output signal from the phase shifter is amplified and input to the drive for exciting the resonating mass, to thereby form a closed resonance loop for controlling the oscillation amplitude of the resonating mass.

Claims

1. A controller for controlling a sensor having a resonating mass, comprising:

a signal conditioning chain responsive to a sensor signal from the sensor and operative to extract a digitized sensor signal from the sensor signal;

a frequency/phase controller responsive to the digitized sensor signal and operative to generate a frequency/phase-controlled signal that is locked in phase with the digitized sensor signal;

an amplitude controller responsive to the digitized sensor signal and operative to generate an amplitude-adjusted signal; and

a modulator/phase-shifter responsive to the amplitude-adjusted signal and operative to modulate and shift a phase of the amplitude-adjusted signal to thereby generate a modulated signal,

wherein the resonating mass is configured to be excited based on the modulated signal, to thereby form a closed resonance loop for controlling an oscillation amplitude of the resonating mass.

2. The controller according to claim 1, wherein the signal conditioning chain includes:

an analog-to-digital converter responsive to the sensor signal and operative to convert the sensor signal into a digital signal; and

a demodulator responsive to the digital signal and operative to extract the digitized sensor signal, the digitized sensor signal representing an envelope of the oscillation amplitude of the resonating mass and a phase error between the sensor signal and an internal clock reference.

3. The controller according to claim 1, wherein the signal conditioning chain further includes:

a low pass filter responsive to the digitized sensor signal and operative to filter a noise from the digitized sensor signal.

4. The controller according to claim 1, wherein the signal conditioning chain further includes:

a front end circuit responsive to an electrical signal from the sensor and operative to convert the electrical signal into a voltage signal.

5. The controller according to claim 4, wherein the signal conditioning chain further includes:

a sample and hold responsive to the voltage signal and operative to sample data from the voltage signal and hold the data during a set of time period.

6. The controller according to claim 1, further comprising:

a digital-to-analog converter (DAC) responsive to the frequency/phase-controlled signal and operative to convert the frequency/phase-controlled signal into an analog signal.

7. The controller according to claim 6, further comprising:

a sigma-delta digital modulator responsive to the frequency/phase-controlled signal and operative to modulate the frequency/phase-controlled signal before the frequency/phase-controlled signal is input to the DAC.

8. The controller according to claim 1, further comprising:

a digital-to-analog converter (DAC) responsive to the modulated/phase-shifted signal and operative to convert the modulated/phase-shifted signal to an analog signal for driving the resonating mass.

9. The controller according to claim 8, further comprising:

a sigma-delta digital modulator responsive to the modulated/phase-shifted signal and operative to modulate the modulated/phase-shifted signal before the modulated/phase-shifted signal is input to the DAC.

10. The controller according to claim 8, further comprising:

an amplifier responsive to the analog signal and operative to amplify the analog signal.

11. The controller according to claim 8, wherein the sensor signal indicates a displacement of the resonating mass and a phase difference between the analog signal and the sensor signal is 90 degrees.

12. The controller according to claim 8, wherein the sensor signal indicates a velocity of the resonating mass and the analog signal is in phase with the sensor signal.

13. The controller according to claim 1, wherein the sensor is a gyroscope for measuring a rate of rotation of the sensor.

14. A method of controlling a sensor having a resonating mass, comprising:

converting a sensor signal into a digital format to thereby generate a digitized sensor signal, the sensor signal indicating at least one of a displacement and a velocity of the resonating mass;

controlling a frequency and a phase of an internal clock reference to thereby lock a system clock signal in phase to the digitized sensor signal;

adjusting an amplitude of a signal derived from the digitized sensor signal to generate an adjusted amplitude signal;

shifting a phase of the adjusted amplitude signal by a predetermined angle;

modulating the phase-shifted signal; and

based on the modulated signal, generating a signal for driving the resonating mass.

15. The method according to claim 14, where the step of converting a sensor signal into a digitized sensor signal includes:

filtering a noise from the digitized sensor signal.

16. The method according to claim 14, wherein the step of generating a signal for driving the resonating mass includes:

converting the modulated signal into an analog signal; and

amplifying the analog signal to generate the signal for driving the resonating mass.

17. The method according to claim 14, wherein the sensor is a gyroscope for measuring a rate of rotation of the sensor.

18. The method according to claim 14, wherein the sensor signal indicates the displacement of the resonating mass and the predetermined angle is 90 degrees.

19. The method according to claim 14, wherein the sensor signal indicates the velocity of the resonating mass and the predetermined angle is 0 degree.