Process device with process variable measurement using image capture device

• US 10,823,592 B2
• Filed: 09/26/2013
• Issued: 11/03/2020
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hedtke, Robert C.
• Primary Examiner(s): Ortiz Rodriguez, Carlos R
• Application Number:
  US14/038,185
• Publication Number:
  US 20150085104A1
• Time in Patent Office: 2,595 Days
• CPC Class Codes: G01F 1/3282 for detecting variations in infrasonic, sonic or ultrasonic waves, due to modulation by passing through the swirling fluid
• CPC Class Codes: G05B 2219/25428 Field device
• CPC Class Codes: G06T 2207/20056 Discrete and fast Fourier transform, [DFT, FFT]
• CPC Class Codes: G06T 2207/30108 Industrial image inspection
• CPC Class Codes: G06T 2207/30241 Trajectory
• CPC Class Codes: G06T 7/262 using transform domain methods, e.g. Fourier domain methods
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A field device for monitoring a process variable of an industrial process includes an image capture device. A process component exhibits relative motion as a function of a process variable. The image captures device captures an image which changes due to the relative motion of the process component. An image processor coupled to the image capture device detects relative motion of the process component and measures the process variable based upon the detected relative motion. Output circuitry provides an output related to the measured process variable.

Claims

1. A field device for monitoring a process variable of an industrial process, comprising:

a mechanical process component which exhibits relative mechanical motion with respect to a reference as a function of the process variable, wherein the process variable comprises a process variable of a process fluid and the process variable causes the relative mechanical motion of the mechanical process component by applying a force to the mechanical process component, wherein the relative motion comprises deformation or repetitive motion;

an image capture device configured to capture an image which changes due to relative motion of the process component;

an image processor coupled to the image capture device configured to;

detect relative motion comprising deformation or repetitive motion of the process component based upon the captured image; and

 

indirectly measure the process variable based upon detected relative motion; and

output circuitry coupled to the image processor configured to provide an output related to the measured process variable;

wherein the process variable is selected from the group of process variables consisting of pressure, temperature, flow rate, level, speed, and mass wherein the detected motion comprises a frequency or an amplitude of the relative motion.

2. The field device of claim 1 wherein the relative motion comprises displacement of the process component.

3. The field device of claim 1 including a radiation source configured to illuminate the process component and wherein the image capture device receives an image of the process component illuminated by the radiation source.

4. The field device of claim 1 wherein the image capture device comprises a single pixel sensor.

5. The field device of claim 1 wherein the image capture device comprises a line scan sensor.

6. The field device of claim 1 wherein the image capture device comprises a two-dimensional array.

7. The field device of claim 1 wherein the image processor is further configured to perform diagnostics on the industrial process based upon the captured image.

8. The field device of claim 1 including a memory configured to store a baseline image for use by the image processor in detecting relative motion of the process component.

9. The field device of claim 1 wherein the image capture device captures an image of the process component.

10. The field device of claim 1 wherein the image capture device moves with the process component and captures an image of a reference element.

11. The field device of claim 1, including a control element used to control the industrial process based upon a control signal and wherein the control signal is a function of the output related to the measured process variable.

12. A method for monitoring a process variable of an industrial process using a field device, comprising:

placing a mechanical process component in the industrial process which exhibits relative mechanical motion with respect to a reference as a function of the process variable, wherein the process variable comprises a process variable related to a process fluid and the process variable causes the relative mechanical motion of the mechanical process component by applying a force to the mechanical process component, wherein the relative motion comprises deformation or repetitive motion;

capturing an image which changes due to relative motion of the process component, the relative motion related to the process variable;

detecting the relative motion of the process component in the captured image;

indirectly measuring the process variable based upon the detected relative motion; and

responsively providing an output related to the process variable;

wherein the process variable is selected from the group of process variables consisting of pressure, temperature, flow rate, level, speed, and mass wherein the detected motion comprises a frequency or an amplitude of the relative motion.

13. The method of claim 12 wherein the relative motion comprises displacement of the process component.

14. The method of claim 12 wherein the detected motion comprises an amplitude in the captured image.

15. The method of claim 12 including illuminating the process component with a radiation source.

16. The method of claim 12 including performing diagnostics on the industrial process based upon the captured image.

17. The method of claim 12 including storing a baseline image in a memory for use in detecting relative motion of the process component.