Patent ID: 8271141

Claim:
A fluid control valve system comprising: a valve body having an elongated bore in communication with an inlet port and an outlet port; a valve element movable within the bore between first and second positions, wherein the outlet port is selectably coupled to the inlet port according to the position of the valve element; at least one valve sensor mounted in relation to the valve body for generating a sensor signal indicative of at least one instantaneous parameter of the valve that changes between the first and second positions; a pilot mounted to the valve body adapted to receive a pilot command signal and to move the valve element in response to the pilot command signal; and a logic unit receiving the sensor signal and the pilot command signal, wherein a predetermined change in the pilot command signal causes the logic unit to determine a cycle parameter responsive to a time period between two predetermined events, wherein at least the beginning or end of the time period corresponds to a predetermined value of the sensor signal, and wherein the logic unit operates in a baseline mode, a monitoring mode, and an adaptive mode; wherein the baseline mode comprises an initial predetermined number of cycles of the pilot command signal, and wherein individual determinations of the cycle parameter are accumulated to obtain an expected cycle parameter; wherein the monitoring mode is utilized after completion of the baseline mode, and wherein the logic unit generates an indication signal when the cycle parameter during the monitoring mode exhibits a predetermined variance from the expected cycle parameter, wherein in the adaptive mode the expected cycle parameter is determined by statistically calculating an upper control limit and a lower control limit in response to individual determinations of the cycle parameter within a predetermined window, and wherein the predetermined variance is comprised of the cycle parameter being above the upper control limit or below the lower control limit.