Methods and apparatus to limit a change of a drive value in an electro-pneumatic controller
AssigneeFisher Controls International LLC
InventorStephen George Seberger
Life of this patent
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Abstract
Example methods and apparatus to limit a change of a drive value in an electro-pneumatic controller are disclosed. A disclosed example method includes receiving a control signal and a feedback signal, calculating from the control signal and the feedback signal a drive value, determining if a difference between the drive value and a previous drive value is greater than a slew limit of the electro-pneumatic controller, and changing the calculated drive value based on the slew limit.
Claims25
A method to limit a change of a drive value in an electro-pneumatic controller, the method comprising:
- receiving a control signal and a feedback signal;
- calculating from the control signal and the feedback signal a drive value;
- determining if a difference between the drive value and a previous drive value is greater than a slew limit of the electro-pneumatic controller;
- and
- changing the calculated drive value based on the slew limit.
An apparatus to limit a change of a drive value in an electro-pneumatic controller, the apparatus comprising a drive current slew limiter to:
- receive a drive value and a previous drive value;
- determine if a difference between the drive value and the previous drive value is greater than a slew limit of the electro-pneumatic controller;
- and
- change the calculated drive value based on the slew limit.
A machine-accessible medium having instructions stored thereon that, when executed, cause a machine to:
- receive a control signal and a feedback signal;
- calculate from the control signal and the feedback signal a drive value;
- determine if a difference between the drive value and a previous drive value is greater than a slew limit of an electro-pneumatic controller;
- and
- change the calculated drive value based on the slew limit.
Dependencies are inferred from the claim text.