Methods and apparatus to arbitrate valve position sensor redundancy
AssigneeEmerson Process Management Power & Water Solutions, Inc.
InventorsThomas Sweeney, Scott Shaw, Peter Nicholas Francino
Life of this patent
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Abstract
Example methods and apparatus to arbitrate valve position sensor redundancy are disclosed. A disclosed example method comprises measuring a first value representative of a position of a valve, measuring a second value representative of the position of the valve, computing a first estimated position of the valve, selecting one of the first and second values based on the first estimated position, and generating a first valve control signal for the valve based on the selected one of the first and second values.
Claims24
A method comprising:
- computing a first difference between first and second values representative of a position of a valve according to a first sensor;
- computing a second difference between third and fourth values representative of the position of the valve according to a second sensor different from the first sensor;
- computing a third difference between first and second estimated positions of the valve;
- comparing the first difference to the third difference;
- comparing the second difference to the third difference;
- and
- selecting one of the first and second sensors for use in generating a first valve control signal for the valve based on the comparison of the first difference to the third difference and the comparison of the second difference to the third difference.
An apparatus comprising:
- a first sensor to measure first and second values representative of first and second positions of a valve actuator;
- a second sensor to measure third and fourth values representative of third and fourth positions of the valve actuator;
- a modeler to compute first and second estimated positions of the valve actuator;
- a comparator to compute a first difference between the first and second values, to compute a second difference between the third and fourth values, and to compute a third difference between the first and second estimated positions of the valve actuator;
- an arbiter to select one of the first and second sensors based on a comparison between the first difference and the third difference and on a comparison between the second difference and the third difference;
- and
- a controller to generate a first valve control signal for the valve actuator based on the selected one of the first and second sensors.
A tangible computer readable storage medium comprising machine readable instructions that, when executed, cause a machine to at least:
- compute a first difference between first and second values representative of a position of a valve actuator according to a first position sensor;
- compute a second difference between third and fourth values representative of the position of the valve actuator according to a second position sensor;
- compute a third difference between first and second estimated positions of the valve actuator;
- compare the first difference to the third difference;
- compare the second difference to the third difference;
- select one of the first and second position sensors for use in generating a first valve control signal for the valve actuator based on the comparison of the first difference to the third difference and the comparison of the second difference to the third difference.
Dependencies are inferred from the claim text.