Systems and methods for reporting a cause of an event or equipment state using causal relationship models in a building management system

• US 8,655,830 B2
• Filed: 11/05/2010
• Issued: 02/18/2014
• Est. Priority Date: 10/06/2009
• Status: Active Grant

• Current Assignee: Tyco Fire & Security GmbH (Johnson Controls International plc)
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Mackay, Douglas P.
• Primary Examiner(s): Chaki, Kakali
• Assistant Examiner(s): RIOJAS RAMIREZ, MARIO
• Application Number:
  US12/940,853
• Publication Number:
  US 20110137853A1
• Time in Patent Office: 1,201 Days
• Field of Search: None
• US Class Current: 706/55
• CPC Class Codes: G01M 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: G05B 23/0248 Causal models, e.g. fault tree; digraphs; qualitative physics
• CPC Class Codes: G06F 2201/86 Event-based monitoring
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling

Abstract

A computerized method for evaluating and reporting a cause of a performance change in a building management system is shown and described. The method includes receiving an indication of a fault for building equipment of the building management system and determining a root cause for the fault by traversing a causal relationship model including the building equipment and other devices of the building management system.

Claims

1. A computerized method for evaluating and reporting a cause of a performance change in a building management system, comprising:

receiving, at a processing circuit, an indication of a fault for building equipment of the building management system, wherein the indication of the fault is directly associated with an indicator building object;

receiving, at the processing circuit, a causal relationship model including the indicator building object and other building objects of the building management system, wherein the causal relationship model is an ontological model describing causal relationships between pairs of building objects, wherein each of the causal relationships is a directional relationship between a first building object and a second building object, wherein the causal relationship model includes an indication of a relationship direction and an indication of a relationship type for each of the causal relationships, wherein the indication of the relationship type identifies an effect of multiple possible effects that the first building object has on the second building object; and

using the processing circuit to determine a root cause of the fault by traversing the causal relationship model, wherein the root cause of the fault is directly associated with a building object causally related to the indicator building object.

2. The computerized method of claim 1, wherein using the processing circuit to determine a root cause further comprises:

identifying a building object directly associated with the fault;

determining a causally-related building object using the identified building object and the causal relationship model traversal;

retrieving historical data for the causally-related building object; and

using the historical data to identify a cause of the fault.

3. The computerized method of claim 2, wherein the historical data comprises at least one of:

time series data, performance index information, and an event history.

4. The computerized method of claim 1, wherein using the processing circuit to determine a root cause further comprises:

identifying a building object directly associated with the fault;

retrieving a causal relationship model for the identified building object;

traversing the causal relationship model to identify a causally-related building object;

retrieving event data for the causally-related building object;

analyzing the event data to identify an abnormal event; and

identifying the root cause based on the results of the analysis.

5. The computerized method of claim 1, further comprising:

traversing multiple levels of a causal relationship model to find the root cause of the fault, wherein at least one of the multiple levels includes a device of the building management system which is indirectly causally-related to the building equipment for which the indication of a fault is received.

6. The computerized method of claim 1, wherein using the processing circuit comprises:

retrieving historical data for the other devices of the building management system using the causal relationship model;

identifying a plurality of possible abnormalities in the historical data;

using time data in the historical data to identify the earliest abnormality as the root cause of the fault.

7. The computerized method of claim 6, further comprising:

excluding an earliest abnormality in the historical data due to a determined inconsistency with the causal relationship model.

8. The computerized method of claim 1, wherein using the processing circuit to determine a root cause further comprises:

traversing the causal relationship model to identify the other devices of the building management system;

retrieving historical data for each identified device;

processing the historical data to identify possible abnormalities;

using time data for the possible abnormalities to determine the earliest identified abnormality; and

evaluating causal relationships to determine if the earliest abnormality could have been the root cause of the fault.

9. The computerized method of claim 8, wherein using the processing circuit further comprises:

traversing the causal relationship model to identify additional devices in response to a determination that the causal relationship indicates that the earliest abnormality could not have been the root cause of the fault.

10. The computerized method of claim 1, further comprising:

using performance indexes, the causal relationship model, and event data to determine which of a plurality of historical building management system events is associated with the root cause for the fault.

11. A computer system for evaluating and reporting a cause of a performance change in a building management system, comprising:

a processing circuit configured to receive an indication of a fault associated with building equipment of the building management system, wherein the indication of the fault is directly associated with an indicator building object;

wherein the processing circuit is configured to determine a root cause of the fault by traversing a causal relationship model including the indicator building object and other building objects of the building management system, wherein the causal relationship model is an ontological model describing casual relationships between pairs of building objects, wherein each of the causal relationships is a directional relationship between a first building object and a second building object, wherein the causal relationship model includes an indication of a relationship direction and an indication of a relationship type for each of the causal relationships, wherein the indication of the relationship type identifies an effect of multiple possible effects that the first building object has on the second building object, and wherein the root cause of the fault is directly associated with a building object causally related to the indicator building object.

12. The computer system of claim 11, wherein the processing circuit is further configured to:

identify a building object associated with the fault;

determine a causally-related building object using the identified building object and the causal relationship model;

retrieve historical data for the causally-related building object from a memory; and

use the historical data to identify a cause of the fault.

13. The computer system of claim 11, wherein the processing circuit comprises a memory and the memory comprises a fault cause analyzer that traverses multiple levels of a causal relationship model until the root cause for the fault is determined, wherein at least one of the multiple levels includes a device of the building management system which is indirectly causally-related to the building equipment for which the indication of a fault is received.

14. The computer system of claim 11, wherein the processing circuit is further configured to:

identify a building object associated with the fault;

retrieve a causal relationship model for the identified building object;

traverse the causal relationship model to identify a causally-related building object;

retrieve event data for the causally-related building object;

analyze the event data to identify an abnormal event; and

identify the root cause based on the results of the analysis.

15. The computerized method of claim 11, wherein the causal relationship model comprises a plurality of software defined building objects and wherein at least two of the software defined building objects belong to different building subsystems.

16. The computer system of claim 11, wherein the processing circuit is further configured to:

retrieve historical data for devices related to the building equipment using the causal relationship model;

identify possible abnormalities in the historical data; and

use time data in the historical data to identify the earliest abnormality as the root cause of the fault.

17. The computer system of claim 11, wherein the processing circuit further comprises a system analysis module and the system analysis module comprises an event analyzer, a causal relationship analyzer, a performance index analyzer, and a fault cause analyzer, wherein the fault cause analyzer coordinates the causal relationship traversal, and wherein the fault cause analyzer uses information from the event analyzer and the performance index analyzer to select from a plurality of possible root causes for the fault.

18. The computer system of claim 11, wherein the processing circuit is further configured to:

traverse the causal relationship model to identify other devices;

retrieve historical data for each identified device;

process the historical data to identify possible abnormalities;

use time data for the possible abnormalities to determine the earliest identified abnormality; and

evaluate causal relationships to determine if the earliest abnormality could have been the root cause of the fault;

wherein the processing circuit is configured to traverse the causal relationship model to identify additional devices if the earliest abnormality is determined to not be the root cause of the fault.

19. The computer system of claim 11, wherein traversing the causal relationship model comprises following causal relationship paths that are not coextensive with hardware, logical, or hardware and logical communications connections of the building management system.

20. A non-transitory computer-readable storage medium having stored thereon machine-readable instructions for causing, when executed, one or more machines to perform the following:

receiving an indication of a fault for building equipment of the building management system, wherein the indication of the fault is directly associated with an indicator building object;

determining a root cause of the fault by traversing a causal relationship model including the indicator building object and other building objects of the building management system, wherein the causal relationship model is an ontological model describing causal relationships between pairs of building objects, wherein each of the causal relationships is a directional relationship between a first building object and a second building object, wherein the causal relationship model includes an indication of a relationship direction and an indication of a relationship type for each of the causal relationships, wherein the indication of the relationship type identifies an effect of multiple possible effects that the first building object has on the second building object, and wherein the root cause of the fault is directly associated with a building object causally related to the indicator building object; and

reporting a cause of a performance change in a building management system based on the determined root cause of the fault.