Event-driven fault diagnosis framework for automotive systems

A method for diagnosing causes of faults and making a prognosis of system health in vehicle systems, said method comprising:

• defining a plurality of diagnostic trouble codes which are applicable to various fault conditions in a vehicle's systems, criteria for triggering each diagnostic trouble code, and a list of parameter identification data which should be captured for each diagnostic trouble code;
• providing a controller onboard a vehicle which is programmed with the diagnostic trouble codes and the criteria for triggering each diagnostic trouble code, and which is also programmed with the list of parameter identification data which should be captured for each diagnostic trouble code;
• providing sensors onboard the vehicle as needed to capture the parameter identification data;
• capturing the diagnostic trouble code and parameter identification data by the controller when a fault condition occurs in a vehicle system, where each fault condition occurrence is known as a fault event, and data captured for each fault event also includes a time stamp;
• downloading the diagnostic trouble code and parameter identification data and time stamps from the controller on the vehicle to a central computer;
• storing diagnostic trouble code and parameter identification data and time stamps for fault events from multiple vehicles on the central computer, where each fault event has an actual failure mode attributed to it;
• analyzing the diagnostic trouble code and parameter identification data from the fault events stored on the central computer using mathematical models which can learn to correlate features in the data with the actual failure mode for each fault event, including a training phase and a testing phase;
• using the mathematical models to diagnose a failure mode for additional fault events;
• and
• using the diagnostic trouble code and parameter identification data and the time stamp for each fault event to make a prognosis of system health and remaining useful life for any system involved in the fault event.

A system for diagnosing causes of faults in vehicle systems, said system comprising:

• a vehicle with a plurality of systems to be monitored;
• a plurality of sensors onboard the vehicle for measuring various conditions in the systems;
• a controller onboard the vehicle, where the controller is configured to receive parameter data from the sensors, monitor the parameter data to determine if any fault conditions exist, and capture and store a plurality of parameter data when a fault event occurs;
• a central computer for collecting parameter data for fault events from a plurality of vehicles, where the computer uses mathematical models to analyze the parameter data to diagnose failure modes for groups of fault events and for individual fault events, said mathematical models comprising a data pre-processing module including normalization and variance reduction techniques, a feature extraction module including key statistics, principal component analysis, and partial least squares techniques, and a trained classifier module including support vector machine, probabilistic neural networks, k-nearest neighbor, decision trees, linear discriminant analysis, and quadratic discriminant analysis techniques;
• and
• a communications system onboard the vehicle for transmitting the parameter data for fault events to the central computer.