1. A method for detecting and characterizing an occurrence of at least one event during operation of a valve actuator as one of a deviation, malfunction or failure, the method comprising the steps of: detecting a series of signals received from a plurality of sensors, where each signal represents a condition of a different operational variable associated with the actuator; determining from the signals one or more of the operational variables that caused the occurrence of the at least one event; determining at least one relationship between the one or more variables and the event, wherein the at least one relationship includes a time-related succession of intermediate states of operation associated with the valve actuator that are interconnected by transition paths, which are quantified by cause-and-effect relationships and temporal and likelihood factors; characterizing the event as being one of a normal mode of operation, a deviation, malfunction or failure; and communicating the at least one relationship through an output device.
1. A method for detecting and characterizing an occurrence of at least one event during operation of a valve actuator as one of a deviation, malfunction or failure, the method comprising the steps of: detecting a series of signals received from a plurality of sensors, where each signal represents a condition of a different operational variable associated with the actuator; determining from the signals one or more of the operational variables that caused the occurrence of the at least one event; determining at least one relationship between the one or more variables and the event, wherein the at least one relationship includes a time-related succession of intermediate states of operation associated with the valve actuator that are interconnected by transition paths, which are quantified by cause-and-effect relationships and temporal and likelihood factors; characterizing the event as being one of a normal mode of operation, a deviation, malfunction or failure; and communicating the at least one relationship through an output device. 6. The method of claim 1 , wherein the step of determining the at least one relationship between the one or more variables and the event comprises the steps of: identifying recurring events and identifying the trajectory of the events; and determining a state of operation of the actuator.