Systems and methods for distributed algorithm for optimization-based diagnosis

A diagnostic system usable to diagnose a component of a physical system, comprising:

• an initialization circuit, routine or application that initializes the diagnosis system to an initial diagnosis;
• a local diagnosis circuit, routine or application that generates one or more candidate local diagnoses based on a physical value received from a sensor monitoring the component, the physical value describing a state of the component;
• a diagnosis management circuit, routine or application that selects a local diagnosis from among the one or more candidate local diagnoses;
• and
• a remote diagnosis management circuit, routine or application that communicates with a second diagnostic system, wherein zero, one or more of the candidate local diagnoses are based in part on a second local diagnosis generated by the second diagnostic system.

A method for diagnosing a physical system, the system comprising a plurality of physical components being diagnosed by a plurality of local diagnostic subsystems, the method comprising:

• initializing a first local diagnostic subsystem to an initial diagnosis;
• assigning an observation value to an observation variable of the first local diagnostic subsystem, wherein the observation value corresponds to a physical value received from a sensor monitoring a first component and describing a state of the first component;
• performing a first local diagnosis in the first local diagnostic subsystem to determine a minimal cost diagnosis explaining the observation value;
• determining whether the lowest cost diagnosis requires a change in the value of a pseudo-assumption variable of the first local diagnostic subsystem to a desired value;
• performing a second local diagnosis in the first local diagnostic subsystem in which the value of the pseudo-assumption variable is held constant to determine a maximum cost;
• supplying a desired value and the determined maximum cost to a second local diagnostic subsystem where the second local diagnostic subsystem contains a pseudo-observation variable corresponding to the pseudo-assumption variable of the first local diagnostic subsystem;
• performing a third local diagnosis in the second local diagnostic subsystem to determine whether a diagnosis in which the pseudo-observation variable is set to the desired value can be performed for a cost less than the maximum cost;
• adopting the first local diagnosis in the first local diagnostic subsystem when the third local diagnosis can not be performed for a cost less than the maximum cost;
• and
• adopting the second local diagnosis in the first local diagnostic subsystem when the third local diagnosis can be performed for a cost less than the maximum cost.