Systems and methods for monitoring sensors

Patent metadata

Field	Value
Publication number	US-9389260-B2
Application number	US-201213630939-A
Country	US
Kind code	B2
Filing date	Sep 28, 2012
Priority date	Sep 28, 2012
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

An impedance analyzer is provided. The analyzer includes a signal excitation generator comprising a digital to analog converter, where a transfer function of the digital to analog converter from digital to analog is programmable. The impedance analyzer further includes a receiver comprising a low noise amplifier (LNA) and an analog to digital converter (ADC), where the LNA is a current to voltage converter; where the programmable digital to analog transfer function is implemented by a direct digital synthesizer (DDS) and a voltage mode digital to analog converter, or a digital phase locked loop (PLL), or both. Further, a multivariable sensor node having an impedance analyzer is provided. Furthermore, a multivariable sensor network having a plurality of multivariable sensor nodes is provided.

First claim

The invention claimed is:

1. A multivariable sensor node comprising: a resonant sensor; an impedance analyzer comprising an analog to digital converter (ADC) and a master clock for the ADC, wherein a number of bits in the ADC is reduced to reduce a total power consumption of the impedance analyzer, and wherein a speed of the master clock for the ADC is dynamically adjusted based on an excitation frequency, wherein the impedance analyzer is configured to monitor a plurality of responses from the resonant sensor, and wherein the resonant sensor and the impedance analyzer form a single-chip arrangement in the multivariable sensor node; a data transmitter configured to transmit sensor data from the resonant sensor; and an on-board electrical energy source configured to power the impedance analyzer and the data transmitter.

2. The multivariable sensor node of claim 1 , wherein the on-board electrical energy source comprises an energy harvesting element.

3. The multivariable sensor node of claim 2 , wherein the energy harvesting element is configured to harvest energy from an ambient environment comprising a thermal energy source, a radio frequency energy source, a light energy source, a vibration energy source, a motion energy source, or combinations thereof.

4. A multivariable sensor node, comprising:
a resonant sensor;
an impedance analyzer configured to monitor a resonance property of the resonant sensor, wherein the impedance analyzer comprises:
an analog to digital converter (ADC), wherein a number of bits in the ADC is reduced to reduce a total power consumption of the impedance analyzer;
a voltage excitation generator comprising a direct digital synthesizer (DDS), a digital phase locked loop (PLL), or both, and a voltage-mode digital to analog converter (DAC);
a receiver comprising a current-to-voltage converter (CVC) trans-impedance amplifier; and
a master clock for the DDS, DAC, and ADC, wherein a speed of the master clock for the DDS, DAC, and ADC is dynamically adjusted based on an excitation frequency,
wherein the resonant sensor and the impedance analyzer form a single-chip arrangement in the multivariable sensor node.

5. The multivariable sensor node of claim 4 , wherein the impedance analyzer is configured for multi-channel measurements.

6. The multivariable sensor node of claim 4 , wherein the digital phase locked loop of the voltage excitation generator is configured to generate two signals in quadrature, and wherein the receiver comprises the ADC and a mixer to down-convert a resonant sensor signal to a lower frequency.

7. The multivariable sensor node of claim 6 , wherein the resonant sensor is part of an impedance analyzer signal source, and wherein the impedance analyzer further comprises:
an amplitude control loop to regulate an excitation amplitude of the resonant sensor; and
a phase control loop configured to detect a phase of the resonant sensor signal.

8. A multivariable sensor node, comprising:
a sensor;
an impedance analyzer configured to monitor a frequency response of the sensor, wherein the impedance analyzer comprises:
a voltage excitation generator comprising a direct digital synthesizer (DDS) and a voltage-mode digital to analog converter (DAC);
a receiver comprising a current-to-voltage converter (CVC) trans-impedance amplifier and an analog to digital converter (ADC), wherein a number of bits in the ADC is reduced to reduce a total power consumption of the impedance analyzer, and
a master clock for the DDS, DAC, and ADC, wherein a speed of the master clock for the DDS, DAC, and ADC is dynamically adjusted based on an excitation frequency,

wherein the impedance analyzer and the sensor are integrated into a single-chip to form the multivariable sensor node.

9. The multivariable sensor node of claim 8 , where the sensor is a non-resonant sensor.

Assignees

• Gen Electric

Inventors

• Potyrailo Radislav Alexandrovich
• Ashe Jeffrey Michael
• Hasan Sm Shajed
• Rao Naresh Kesavan
• Sundaresan Krishnakumar

Classifications

• G01R31/2824

  testing of oscillators or resonators · CPC title

• G01R27/28 Primary

  Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks; Measuring transient response (in line transmission systems H04B3/46) · CPC title