Systems and methods for retraining outlier detection limits in a building management system
First Claim
1. A building management system comprising:
- one or more sensors that measure a variable state or condition representing an output of a controlled process in the building management system;
building equipment that operate to affect the variable state or condition of a building environment measured by the one or more sensors; and
a controller in communication the building equipment and the one or more sensors, wherein the controller;
provides a control signal to the building equipment, the control signal causing the building equipment to operate to affect the variable state or condition of the building environment measured by the one or more sensors;
monitors performance values for the controlled process during a first time period relative to initial outlier detection limits;
generates new outlier detection limits for the controlled process in response to a detected change in the controlled process during the first time period;
outputs a user alert message comprising a fault event notification in response to the detected change in the controlled process;
monitors the performance values relative to the new outlier detection limits during a second time period to detect outliers during the second time period;
calculates a confidence difference for an estimated confidence parameter based on a number of outliers detected using the new outlier detection limits during the second time period, wherein the estimated confidence parameter is a ratio of a number of outliers detected during the second time period to a number of the performance values observed during the second time period; and
adjusts the new outlier detection limits in response to the confidence difference dropping below a threshold value.
3 Assignments
0 Petitions
Accused Products
Abstract
A building management system (BMS) includes a controller that monitors performance values for a controlled process during a first time period relative to initial outlier detection limits and generates new outlier detection limits for the controlled process in response to a detected change in the controlled process during the first time period. The controller monitors the performance values relative to the new outlier detection limits during a second time period to detect outliers during the second time period. The controller calculates a confidence difference for an estimated confidence parameter based on a number of outliers detected using the new outlier detection limits during the second time period. The controller adjusts the new outlier detection limits in response to the confidence difference dropping below a threshold value.
-
Citations
19 Claims
-
1. A building management system comprising:
-
one or more sensors that measure a variable state or condition representing an output of a controlled process in the building management system; building equipment that operate to affect the variable state or condition of a building environment measured by the one or more sensors; and a controller in communication the building equipment and the one or more sensors, wherein the controller; provides a control signal to the building equipment, the control signal causing the building equipment to operate to affect the variable state or condition of the building environment measured by the one or more sensors; monitors performance values for the controlled process during a first time period relative to initial outlier detection limits; generates new outlier detection limits for the controlled process in response to a detected change in the controlled process during the first time period; outputs a user alert message comprising a fault event notification in response to the detected change in the controlled process; monitors the performance values relative to the new outlier detection limits during a second time period to detect outliers during the second time period; calculates a confidence difference for an estimated confidence parameter based on a number of outliers detected using the new outlier detection limits during the second time period, wherein the estimated confidence parameter is a ratio of a number of outliers detected during the second time period to a number of the performance values observed during the second time period; and adjusts the new outlier detection limits in response to the confidence difference dropping below a threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A controller in a building management system, the controller comprising:
-
a communications interface that receives performance values indicating the performance of a controlled process in the building management system, and provides control signals to building equipment, the control signals causing the building equipment to operate to affect the controlled process; an outlier detector that monitors performance values for the controlled process during a first time period relative to initial outlier detection limits and outputs a user alert message comprising a fault event notification in response to a detected change in the controlled process; a control limit trainer that generates new outlier detection limits in response to the detected change in the controlled process during the first time period, wherein the outlier detector monitors the performance values relative to the new outlier detection limits during a second time period to detect outliers during the second time period; a confidence difference calculator that calculates a confidence difference for an estimated confidence parameter based a number of outliers detected using the new outlier detection limits during the second time period; and a stationary process detector that detects when the confidence difference drops below a threshold value during the second time period, wherein the control limit trainer adjusts the new outlier detection limits in response to the confidence difference dropping below the threshold value; wherein the confidence difference calculator generates an estimated confidence parameter for each of the performance values observed during the second time period, and the confidence parameter is a ratio of a number of outliers detected during the second time period to a number of the performance values observed during the second time period. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
-
Specification