Digital closed loop proportional hydraulic pressure controller
AssigneeWoodward, Inc.
InventorKevin E. Greeb
Life of this patent
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Abstract
A digitally controlled current to pressure converter (CPC) and method of controlling same is provided. The method of controlling includes the step of periodically imparting symmetrically-opposed movement of a control valve of the CPC to loosen and flush accumulated silt therefrom. More particularly, the method may include the step of periodically introducing a small-amplitude symmetrically-opposed impulse to a controller that actuates a hydraulic control shaft of a three-way rotary valve. Also provided is a method of preventing malfunction due to faulty input or feedback signals received by the CPC, and a method of detecting the health status of multiple CPCs when used in a redundant configuration.
Claims25
A method of preventing malfunction of a current-to-pressure converter (CPC), comprising the step of periodically imparting symmetrically-opposed movement of a control valve of the CPC to loosen and flush accumulated silt therefrom.
A method of preventing malfunction of the current to pressure converter (CPC) due to an incorrect input signal, comprising the steps of:
- providing redundant input signals to a digital controller;
- monitoring each of the redundant input signals with input diagnostics configured to determine whether the respective redundant input signals are faulty;
- and
- controlling an output pressure of the CPC, wherein the output pressure is determined by using only a non-faulty input signal.
A method comprising the steps of:
- providing at least two current-to-pressure converters (CPCs) in a positioning control system for valves and actuators;
- configuring one of the at least two CPCs as a master CPC, and configuring another of the at least two CPCs as a slave CPC, wherein the master CPC controls a hydraulic pressure within the positioning control system;
- linking the master CPC and slave CPC such that the master CPC knows an operational status of the slave CPC, and the slave CPC knows an operational status of the master CPC;
- and
- the slave CPC taking control of the hydraulic pressure within the positioning control system when operational status of the master CPC indicates failure of the master CPC.
Dependencies are inferred from the claim text.