Mass flow valve controller and control method with set point filter and linearization system based on valve model

Patent metadata

Field	Value
Publication number	US-10969797-B2
Application number	US-201816116786-A
Country	US
Kind code	B2
Filing date	Aug 29, 2018
Priority date	Aug 29, 2018
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A valve control system that includes a gain controller for controlling the linear response of a valve. The system includes a linearization control system coupled to the gain controller to determine a gain value to control the linear response time of the valve and a set point filter coupled to the linearization control system to filter a set point value. The linearization control system determines the gain value from the filtered set point value, at least one real-time fluid parameter value, valve model data, an actuator gain, and a valve model gain.

First claim

What is claimed is:

1. A valve control system for controlling operation of a valve, the valve control system comprising:
a gain controller for sending a drive value to a valve actuator to control linear response time of a valve;
a linearization control system coupled with the gain controller to determine a gain value to control the linear response time of the valve; and
a set point filter coupled to the linearization control system to filter a set point value;
wherein the linearization control system determines at least one controller gain parameter using: a model of the valve to estimate valve position from the filtered set point value, operating conditions, and fluid properties; a model of the valve actuator to calculate the derivative of valve drive with respect to valve position as a function of the estimated valve position; and a flow control model to calculate the derivative of valve position with respect to flow corresponding to the estimated valve position and a real-time flow rate, operating conditions, and fluid properties.

2. The valve control system of claim 1 wherein the set point filter includes a slew-rate limiting filter.

3. The valve control system of claim 2 wherein the set point filter includes a low pass filter.

4. The valve control system of claim 1 wherein the the fluid properties comprises at least two selected from a group comprising fluid pressure, fluid type, flow rate, and fluid temperature.

5. The valve control system of claim 1 wherein the gain value is defined by dY/dx−f′(g(x))g′(x), where Y is controller drive, f′(g(x)) is actuator gain, and g′(x) is the valve model gain, wherein x is the flow rate.

6. The valve control system of claim 1 wherein the linear response time is less than 300 ms and an output response is within 98% of the set point value.

7. A method for controlling operation of a valve, the method comprising:
sending, at a gain controller, a drive value to a valve actuator to control linear response time of the valve;
determining, at a linearization control system coupled with the gain controller, a gain value to control the linear response time of the valve; and
filtering, at a set point filter coupled to the linearization control system, a set point value;
wherein the linearization control system determines at least one controller gain parameter using: a model of the valve to estimate valve position from the filtered set point value, operating conditions, and fluid properties; a model of the valve actuator to calculate the derivative of valve drive with respect to valve position as a function of the estimated valve position; and a flow control model to calculate the derivative of value position with respect to flow corresponding to the estimated valve position and a real-time flow rate, operating conditions, and fluid properties.

8. The method of claim 7 wherein the set point filter includes a slew-rate limiting filter.

9. The method of claim 8 wherein the set point filter includes a low pass filter.

10. The method of claim 7 wherein the gain value is defined by dY/dx=f′(g(x))g′(x), where Y is controller drive, f′(g(x)) is actuator gain, and g′(x) is the valve model gain, wherein x is the flow rate.

11. The method of claim 7 wherein the gain is determined from the filtered set point value, the fluid properties, and a valve specification.

12. The method of claim 7 wherein the linear response time is less than 300 ms and an output response is within 98% of the set point value.

13. The method of claim 7 wherein the gain value is equal to the reciprocal of a feedback signal indicating fluid flow and an output of the gain controller.

14. A control system for controlling valve response time of a valve based system, the control system comprising:
a feedback control system coupled to an actuator of the valve based system to determine a gain value to control the linear response time of a valve; and
a set point filter coupled to the feedback control system to filter a set point value;
wherein the feedback control system determines at least one controller gain parameter using: a model of the valve to estimate valve position from the filtered set point value, operating conditions, and fluid properties; a model of the valve actuator to calculate the derivative of valve drive with respect to valve position as a function of the estimated valve position; and a flow control model to calculate the derivative of valve position with respect to flow corresponding to the estimated valve position and a real-time flow rate, operating conditions, and fluid properties.

15. The control system of claim 14 wherein the set point filter includes a slew-rate limiting filter.

16. The control system of claim 15 wherein the set point filter includes a low pass filter.

17. The control system of claim 14 wherein the the fluid properties comprises at least two selected from a group comprising fluid pressure, fluid type, and fluid temperature.

18. The control system of claim 14 wherein the gain value is defined by DY/dx=f′(g(x))g′(x), where Y is controller drive, f′(g(x)) is actuator gain, and g′(x) is the valve model gain, wherein x is the flow rate.

19. The control system of claim 14 wherein the gain is equal to the reciprocal of a feedback signal indicating fluid flow and an output of the gain controller.

Assignees

• Illinois Tool Works

Inventors

• Lull John
• Banares Berwin
• Whiteley Jeffrey

Classifications

• G05D7/0635 Primary

  by action on throttling means (G05D7/0688, G05D7/0694 take precedence) · CPC title

• G05D7/0623 Primary

  characterised by the set value given to the control element · CPC title

• G05B17/02

  electric · CPC title