Patent ID: 7496465

Claim:
A method, comprising: initiating a test of an actuator in a process control system, wherein the test includes providing a varying control signal to the actuator, the varying control signal including a varying pressure signal; analyzing a response of the actuator to the varying control signal to determine if the actuator is suffering from one or more faults; and providing at least one notification identifying any identified faults; wherein analyzing the response of the actuator comprises: generating a pressurization curve for the actuator, the pressurization curve identifying how a pressure in the actuator varies over time in response to the varying pressure signal; selecting two polynomial curves that best fit the pressurization curve; identifying a maximum positive deviation and a maximum negative deviation of the pressurization curve from each of the polynomial curves; summing the maximum positive and negative deviations for the polynomial curves; and determining if the sum exceeds a threshold; and wherein the actuator comprises an actuator in a paper sheet production machine operable to manufacture a paper sheet.