Mass flow controller with onboard diagnostics, prognostics, and data logging

Patent metadata

Field	Value
Publication number	US-9766635-B2
Application number	US-201615006380-A
Country	US
Kind code	B2
Filing date	Jan 26, 2016
Priority date	Jan 20, 2011
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A mass flow controller and method for operating the same is disclosed. The mass flow controller includes a mass flow control system to control the mass flow rate of a fluid, and a data logging component that obtains snapshots of condition-specific-data for each of a plurality of reoccurring condition types, and reduces each snapshot of condition-specific-data to functional parameter values that characterize each snapshot of condition-specific-data, and the data logging component generates statistical values that are stored in a short term data store that characterize multiple functional parameter values that are obtained during each separate occurrence of a specific condition type. A diagnostics component diagnoses failures using current functional parameter values and the statistical values stored in the short-term memory, and a prognostics component predicts failures based upon a collection of data sets that are stored in the long-term memory.

First claim

What is claimed is:

1. A mass flow controller comprising:
a mass flow control system that includes a mass flow sensor to provide an indication of a mass flow rate of a fluid through the mass flow controller, a control valve to regulate a flow of the fluid, and a control component to control a position of the control valve responsive to a set point and the indication of the mass flow rate of the fluid;
a short-term data store;
a data logging component that obtains snapshots of condition-specific-data for each of a plurality of reoccurring types of condition changes that occur in the mass flow control system, and reduces each snapshot of condition-specific-data to functional parameter values that characterize each snapshot of condition-specific-data, and the data logging component generates statistical values that are stored in the short-term data store that characterize multiple functional parameter values that are obtained during each separate occurrence of a specific condition type; and
a diagnostics component that diagnoses failures using current functional parameter values and the statistical values stored in the short-term data store.

2. The mass flow controller of claim 1 , including a long-term second data store, wherein the data logging component stores each of a collection of data sets that include the statistical values in the long term second data store responsive to a predefined event that affects the functional parameter values; and
a prognostics component configured to predict failures based upon the collection of data sets in the long-term memory second data store.

3. The mass flow controller of claim 2 , wherein the prognostics component is configured to perform a trend analysis of one or more of the statistical values to predict the failures.

4. The mass flow controller of claim 3 , wherein the prognostics component is configured to report a predicted failure in response to a valve position increasing over time to achieve a given flow for a given pressure.

5. The mass flow controller of claim 4 , wherein the prognostics component is configured to report a trend of increasing flow sensitivity relative to the valve position that changes responsive to a pressure change event.

6. The mass flow controller of claim 2 , wherein the predefined event is selected from the group consisting of a time period, temperature change, gas type change, flow range change, and orientation change.

7. The mass flow controller of claim 1 , wherein the condition-specific-data is selected from the group consisting of measured flow, pressure, valve position, flow set point, parasitic flow, corrected flow sensor signal, control loop gain, control loop time constant, flow indicator, and flow indicator time constant.

8. The mass flow controller of claim 1 , wherein the functional parameters are selected from the group consisting of pressure change, ratio of valve position change to pressure change, maximum flow error, flow error at the moment of switching to closed-loop control mode, duration of an open-loop control mode, valve start position, transient delay, transient rise time, transient fall time, overshoot, control time, zero offset, and valve shift at steady flow.

9. The mass flow controller of claim 1 , wherein the statistical values are statistical values selected from the group consisting of a mean value, standard deviation, minimum value, and maximum value.

Assignees

• Hitachi Metals Ltd

Inventors

• Smirnov Alexei V
• Albright Patrick
• Jordan Cy
• Nagarajan Arun
• Zolock Michael J
• Johnson Ryan
• Fernandez Alexander

Classifications

• Y10T137/7759

  Responsive to change in rate of fluid flow · CPC title

• Y10T137/0318

  Processes · CPC title

• F16K37/0091

  by measuring fluid parameters · CPC title

• G05D7/0635 Primary

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

• G06F11/34

  Recording or statistical evaluation of computer activity, e.g. of down time, of input/output operation {; Recording or statistical evaluation of user activity, e.g. usability assessment} · CPC title