SYSTEMS AND METHODS FOR USING RULE-BASED FAULT DETECTION IN A BUILDING MANAGEMENT SYSTEM

• US 20110047418A1
• Filed: 10/29/2010
• Published: 02/24/2011
• Est. Priority Date: 06/22/2009
• Status: Active Grant

• Current Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Kummer, James P., Drees, Kirk H., Boettcher, Andrew J.
• Granted Patent: US 8,788,097 B2
• Time in Patent Office: Days
• US Class Current: 714/57
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: G05B 23/00 Testing or monitoring of control systems or parts thereof monitoring of programme-control systems G05B19/048, G05B19/406
• CPC Class Codes: H02J 13/00001 characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 10/40 Display of information, e.g. of data or controls
• CPC Class Codes: Y04S 20/00 Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
• CPC Class Codes: Y04S 20/20 End-user application control systems
• CPC Class Codes: Y04S 20/221 General power management systems
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/124 using wired telecommunication networks or data transmission busses

Abstract

A controller for a building management system includes a system of rules for detecting faults in the building management system. The rules include content conditions and trigger conditions. The content conditions are not checked until one or more of the trigger conditions are met. A rule-based fault detection engine may be implemented by a low level building equipment controller. One or more thresholds for a rule may be automatically or manually adjusted.

Claims

1. A method of detecting faults in a building management system, the method comprising:

at a computer of the building management system, using a stored rule condition to detect a first fault in the building management system;

using the computer to determine a need for a threshold adjustment based on at least one of fault detection data or building management system performance data;

determining a new threshold value for the rule condition;

adjusting the stored rule condition to utilize the new threshold value; and

at the computer, using the adjusted rule condition to detect a second fault in the building management system.

2. The method of claim 1, further comprising causing a graphical user interface to be displayed on an electronic display device, the graphical user interface configured to receive a new threshold value as user input, wherein the rule condition is adjusted in response to the user input.

3. The method of claim 1, wherein a processing circuit completes the determining and adjusting steps automatically and without user input.

4. The method of claim 1, wherein the new threshold value is determined by comparing the threshold to an estimated error for a measurement value obtained from a sensor.

5. The method of claim 1, wherein the new threshold value is determined by comparing an estimated power consumption of a controlled device to an actual power consumption of the controlled device.

6. The method of claim 1, wherein the rule condition comprises a trigger condition and a content condition, and wherein using the adjusted rule condition to detect a fault in the building management system further comprises checking the trigger condition to determine whether to process the content condition.

7. The method of claim 1, wherein the fault detection data comprises a history of detected faults and the computer determines a need for the threshold adjustment by determining when a fault has frequently occurred.

8. A method of detecting faults in a building management system, the method comprising:

using a master controller to control a second controller;

at the second controller, collecting building equipment data from building equipment and using the collected building equipment data to control the building equipment;

at the second controller, processing the collected building equipment data relative to a rule condition;

detecting a fault in the building equipment based on the processing of the collected building equipment data relative to the rule condition; and

reporting the detected fault to the master controller from the second controller.

9. The method of claim 8, wherein the second controller is an equipment controller that directly controls the building equipment.

10. The method of claim 8, wherein the rule condition is selectively used based on an operational state of at least one of the building equipment and the second controller.

11. The method of claim 8, wherein the second controller conducts the collecting, processing, and detecting steps without querying or receiving data from the master controller, another upstream controller, or a downstream controller.

12. The method of claim 8, wherein the equipment controller is an air handling unit controller and the collected building equipment data comprises sensor and actuator data for an air handling unit.

13. The method of claim 8, wherein the controller is the lowest level of controller in the building management system.

14. The method of claim 8, wherein the rule condition comprises a trigger condition and a content condition;

and wherein using the adjusted rule condition to detect a fault in the building management system further comprises checking the trigger condition to determine whether to process the content condition.

15. The method of claim 8, further comprising:

determining a need for a threshold adjustment of the rule condition;

determining a new threshold value for the rule condition; and

adjusting the rule condition to utilize the new threshold value.

16. A method of detecting faults in a building management system, the method comprising:

recalling a stored rule;

identifying a trigger condition and a content condition for the rule;

checking the trigger condition to determine whether to process the content condition; and

detecting a fault by processing the content condition.

17. The method of claim 16, wherein the trigger condition is a time delay based on the amount of time needed for a controller to reach a steady state, and wherein the checking step comprises delaying processing of the content condition for the time delay specified by the trigger condition.

18. The method of claim 16, wherein the trigger condition is based on an operational state of a controller, and wherein the checking step comprises:

recalling the current operational state of the controller from a finite state machine within the controller; and

comparing the trigger condition to the current operational state of the controller.

19. The method of claim 16, wherein the trigger condition is stored within a library of predefined trigger conditions in a memory;

wherein the content condition is stored within a library of predefined content conditions in a memory;

wherein the method comprises building a rule by selecting (a) at least one trigger condition from the library of predefined trigger conditions and (b) at least one content condition from the library of predefined content conditions.

20. The method of claim 16, further comprising:

recalling a trigger condition from a library of predefined trigger conditions;

recalling a content condition from a library of predefined content conditions;

causing a graphical user interface to be displayed on an electronic display device, the graphical user interface configured to receive user input;

associating the trigger condition and the content condition to form a rule in response to the user input; and

storing the rule in a memory.