LOW POWER VIBRATION SENSOR AND WIRELESS TRANSMITTER SYSTEM

• US 20080082296A1
• Filed: 01/26/2007
• Published: 04/03/2008
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Computational Systems Incorporated (Emerson Electric Company)
• Original Assignee: CSI Technology Incorporated (Emerson Electric Company)
• Inventors: Walker, James W., Childress, William E., Robinson, James C., Baldwin, Joseph C.
• Granted Patent: US 7,424,403 B2
• Time in Patent Office: Days
• US Class Current: 702/182
• CPC Class Codes: G01H 1/00 Measuring characteristics of vibrations in solids by using direct conduction to the detector G01H9/00, G01H11/00 take precedence

Abstract

A low power vibration sensor and wireless transmitter system has one or more sensors that sense parameters of a machine including vibration and produces dynamic signals representing the sensed parameters. The system converts the signals to a digital format, digitally filters the signals, and processes the signals. A processor determines a plurality of levels, which represent the characteristics of the signal such as the peak value of a predetermined set of data points of the digital signal. Together, the levels comprise a PeakVue waveform. The processor determines the peak level value for the PeakVue waveform. Also, a true root-mean-square is calculated as the signal is received at the processor. The peak level and the RMS value are communicated wirelessly by a communication module to a control protocol network such as a daisy chain HART or Fieldbus protocol network. The system power supply and the communication module power supply are separate and allow for low power operation.

Claims

1. A measurement instrument comprising:

a. a sensor circuit for sensing a parameter of a machine and producing a dynamic signal based on the sensed parameter;

b. an analog to digital converter for receiving the dynamic signal and for converting the dynamic signal to a digital format producing a digital signal having a plurality of data points;

C. a processor connected to receive the digital signal and for determining a level corresponding to a peak of the digital signal over a predetermined range of data points of the digital signal and for producing level data in a control protocol, the level data corresponding to the determined level;

d. a power supply connected to power the processor and controlled by the processor to manage efficiently power consumption; and

e. a communication module for communicating the level data in a control protocol network.

2. The measurement instrument of claim 1 wherein the processor produces a PeakVue waveform comprising a plurality of g-levels corresponding to a plurality of peaks of the digital signal over a plurality of predetermined, non-overlapping ranges of data points of the digital signal.

3. The measurement instrument of claim 2 wherein the processor determines a peak g-level from the PeakVue waveform.

4. The measurement instrument of claim 3 wherein the communication module comprises:

a. a communication processor for controlling the communication module;

b. a communication power supply connected to power the communication processor; and

c. an antenna connected to the communication processor and for wirelessly communicating the peak g-level to the control protocol network.

5. The measurement instrument of claim 1 wherein the control protocol network is selected from the group consisting of a HART protocol network and a Fieldbus protocol network.

6. The measurement instrument of claim 1 wherein the power supply comprises a battery.

7. The measurement instrument of claim 1 wherein the power supply comprises a solar panel connected to a battery.

8. The measurement instrument of claim 1 further comprising:

a. a second sensor circuit for sensing a second parameter of the machine and producing a second signal based on the sensed second parameter and

b. a second analog to digital converter connected to receive the second signal and for converting the second signal to a digital format producing a second digital signal having a plurality of data points.

9. The measurement instrument of claim 8 wherein the second sensor circuit comprises a temperature sensor for sensing a temperature of the machine and the second signal corresponds to the sensed temperature.

10. The measurement instrument of claim 8 wherein the second sensor circuit comprises a pressure sensor for sensing a pressure of the machine and the dynamic second signal corresponds to the sensed pressure.

11. The measurement instrument of claim 1 further comprising a vibration sensor connected to the analog to digital converter and for sensing a vibration of the machine and producing a vibration signal based on the sensed vibration.

12. The measurement instrument of claim 1 wherein the sensor circuit comprises a vibration sensor circuit for sensing a vibration of the machine and producing a vibration signal based on the sensed vibration.

13. The measurement instrument of claim 1 wherein the processor is also for determining a true root-mean-square value representing a second condition of the machine.

14. The measurement instrument of claim 1 wherein the processor comprises a data processor and a control processor.

15. The measurement instrument of claim 1 wherein the sensor circuit comprises a buffer.

16. A measurement instrument comprising:

a. a sensor circuit for sensing a parameter of a machine and producing a dynamic signal based on the sensed parameter;

b. an analog to digital converter connected to receive the dynamic signal and for converting the dynamic signal to a digital format producing a digital signal; and

c. a processor connected to the analog to digital converter and for receiving the digital signal and determining a true root-mean-square value representing a condition of the machine;

d. a power supply connected to the processor and controlled by the processor to minimize power consumption, the power supply for powering the processor, the sensor, and the analog to digital converter; and

e. a communication module connected to the processor, the communication module comprising;

i. a communication processor for controlling the communication module and communicating the true root-mean-square value to the control protocol network and

ii. a communication power supply connected to the communication processor and for powering the communication processor.

17. The measurement instrument of claim 16 wherein the true root-mean-square value is determined substantially as the processor receives the digital signal.

18. A vibration measurement instrument comprising:

a. a vibration sensor circuit for sensing vibration of a machine and producing a dynamic signal based on the vibration of the machine;

b. an analog to digital converter connected to receive the dynamic signal and for converting the dynamic signal to a digital format producing a digital signal;

c. a processor connected to receive the digital signal and for analyzing the digital signal producing vibration data;

d. a power supply connected to power the processor; and

e. a communication module connected to wirelessly communicate the vibration data to a control protocol network, the communication module comprising;

i. a communication processor for controlling the communication module;

ii. a communication power supply connected to power the communication processor; and

iii. an antenna connected to the communication processor and for wirelessly communicating the vibration data to the control protocol network.

19. The vibration measurement instrument of claim 18 wherein the vibration data comprises a true root-mean-square value representing a condition of the machine.

20. The vibration measurement instrument of claim 18 wherein the vibration data comprises a peak g-level determined from a PeakVue waveform representing a condition of the machine.

21. The vibration measurement instrument of claim 18 wherein the control protocol network is selected from the group consisting of a HART protocol network and a Fieldbus protocol network.