Cut-Off Transition for Control Valve Positioners
AssigneeFisher Controls International LLC
InventorsKenneth W. Junk, Michel K. Lovell, Jimmie L. Snowbarger, Jeffrey D. Seyller
Life of this patent
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Abstract
The present invention includes a method, apparatus, and computer readable medium for controlling a valve. Example embodiments of the present invention described herein utilize a soft cutoff threshold and soft cutoff procedure at which point the controller monotonically ramps a servo set-point to slowly overdrive the servo beyond a calibrated set-point range, wherein the servo transitions into a hard cutoff when the servo set-point reaches a predefined overdrive threshold.
Claims24
A method for controlling a valve, the method comprising:
- providing, by one or more processors, a first cutoff threshold and a second cutoff threshold;
- monitoring, by one or more processors, a servo set-point;
- initiating, by one or more processors, a first cutoff procedure in response to the servo set-point crossing the first cutoff threshold;
- and
- initiating, by one or more processors, a second cutoff threshold in response to the servo set-point crossing the second cutoff threshold.
A system for controlling a valve including one or more processors coupled to a memory and one or more modules stored on the memory, wherein execution of the one or more modules by the one or more processors cause the system to:
- provide a first cutoff threshold and a second cutoff threshold;
- monitor a servo set-point;
- initiate a first cutoff procedure in response to the servo set-point crossing the first cutoff threshold;
- and
- initiate a second cutoff threshold in response to the servo set-point crossing the second cutoff threshold.
A tangible non-transitory computer-readable medium having instructions stored thereon for controlling a valve, the instructions, when executed by one or more processors of a computer system, cause the one or more processors to:
- provide a first cutoff threshold and a second cutoff threshold;
- monitor a servo set-point;
- initiate a first cutoff procedure in response to the servo set-point crossing the first cutoff threshold;
- and
- initiate a second cutoff threshold in response to the servo set-point crossing the second cutoff threshold.
Dependencies are inferred from the claim text.