Hvac system with equipment failure prediction

Patent metadata

Field	Value
Publication number	US-2017293293-A1
Application number	US-201715483667-A
Country	US
Kind code	A1
Filing date	Apr 10, 2017
Priority date	Apr 12, 2016
Publication date	Oct 12, 2017
Grant date	—

Abstract

A system for predicting HVAC equipment failure includes an actuator and a controller. The actuator is coupled to the HVAC equipment and configured to drive the HVAC equipment between multiple positions. The actuator includes a processing circuit configured to collect internal actuator data characterizing an operation of the actuator and a communications circuit coupled to the processing circuit. The communications circuit is configured to transmit the internal actuator data outside the actuator. The controller is configured to provide control signals to the actuator and receive the internal actuator data from the actuator. The controller includes a failure predictor configured to use the internal actuator data to predict a time at which the HVAC equipment failure will occur.

First claim

What is claimed is:

1 . A system for predicting HVAC equipment failure, the system comprising:
an actuator coupled to the HVAC equipment and configured to drive the HVAC equipment between multiple positions, the actuator comprising:
a processing circuit configured to collect internal actuator data characterizing an operation of the actuator; and
a communications circuit coupled to the processing circuit and configured to transmit the internal actuator data outside the actuator; and
a controller configured to provide control signals to the actuator and receive the internal actuator data from the actuator, the controller comprising a failure predictor configured to use the internal actuator data to predict a time at which the HVAC equipment failure will occur.

2 . The system of claim 1 , wherein the actuator comprises a motor and a drive device driven by the motor, the drive device coupled to the HVAC equipment and configured to drive the HVAC equipment between the multiple positions;
wherein the internal actuator data characterizes an operation of the motor.

3 . The system of claim 2 , wherein the internal actuator data comprises a measured or calculated value of an operational variable comprising at least one of:
an electric current provided to the motor; or a torque applied by the motor.

4 . The system of claim 3 , wherein the processing circuit is configured to increase at least one of the electric current provided to the motor or the torque applied by the motor to compensate for increased resistance to movement of the HVAC equipment resulting from degradation of the HVAC equipment over time;
wherein the predicted time at which the HVAC equipment failure will occur is a time at which the electric current provided to the motor or the torque applied by the motor is predicted to reach a failure threshold.

5 . The system of claim 1 , wherein the internal actuator data comprises a measured or calculated value of an operational variable;
wherein the failure predictor is configured to:
monitor the value of the operational variable over time;
predict a time at which the value of the operational variable will reach a failure threshold; and
identify the predicted time at which the value of the operational variable will reach the failure threshold as the predicted time at which the HVAC equipment failure will occur.

6 . The system of claim 5 , wherein the failure predictor is configured to:
identify a plurality of values of the operational variable, each value of the operational variable characterizing the operation of the actuator at a different time since the actuator was installed; generate a plurality of data points representing the values of the operational variable over time, each of the data points comprising a time value and a corresponding value of the operational variable; perform a regression to fit a line to the plurality of data points and identify a slope of the line as a rate-of-change of the operational variable; and predict the time at which the value of the operational variable will reach the failure threshold based on the rate-of-change of the operational variable.

7 . The system of claim 1 , wherein the internal actuator data comprises a measured or calculated value of an operational variable comprising at least one of:
a speed at which the actuator moves the HVAC equipment; a cumulative number of stop/start commands provided to the actuator by the controller; a total distance traveled by the HVAC equipment; or an amount of time required to move the HVAC equipment between the multiple positions.

8 . An actuator in a HVAC system, the actuator comprising:
a motor; a drive device driven by the motor and coupled to HVAC equipment, the drive device configured to drive the HVAC equipment between the multiple positions; a processing circuit configured to collect internal actuator data characterizing an operation of the actuator, the processing circuit comprising a failure predictor configured to use the internal actuator data to predict a time at which a failure of the HVAC equipment will occur; and a communications circuit coupled to the processing circuit and configured to transmit the predicted time at which the HVAC equipment failure will occur outside the actuator.

9 . The actuator of claim 8 , wherein the internal actuator data comprises a measured or calculated value of an operational variable characterizing an operation of the motor, the operational variable comprising at least one of:
an electric current provided to the motor; or a torque applied by the motor.

10 . The actuator of claim 8 , wherein the processing circuit is configured to increase at least one of the electric current provided to the motor or the torque applied by the motor to compensate for increased resistance to movement of the HVAC equipment resulting from degradation of the HVAC equipment over time;
wherein the predicted time at which the HVAC equipment failure will occur is a time at which the electric current provided to the motor or the torque applied by the motor is predicted to reach a failure threshold.

11 . The actuator of claim 8 , wherein the internal actuator data comprises a measured or calculated value of an operational variable;
wherein the failure predictor is configured to:
monitor the value of the operational variable over time;
predict a time at which the value of the operational variable will reach a failure threshold; and
identify the predicted time at which the value of the operational variable will reach the failure threshold as the predicted time at which the HVAC equipment failure will occur.

12 . The actuator of claim 11 , wherein the failure predictor is configured to:
identify a plurality of values of the operational variable, each value of the operational variable characterizing the operation of the actuator at a different time since the actuator was installed; generate a plurality of data points representing the values of the operational variable over time, each of the data points comprising a time value and a corresponding value of the operational variable; perform a regression to fit a line to the plurality of data points and identify a slope of the line as a rate-of-change of the operational variable; and predict the time at which the value of the operational variable will reach the failure threshold based on the rate-of-change of the operational variable.

13 . The actuator of claim 8 , wherein the internal actuator data comprises a measured or calculated value of an operational variable comprising at least one of:
a speed at which the actuator moves the HVAC equipment; a cumulative number of stop/start commands provided to the actuator; a total distance traveled by the HVAC equipment; or an amount of time required to move the HVAC equipment between the multiple positions.

14 . A method for predicting HVAC equipment failure, the method comprising:
operating an actuator coupled to the HVAC equipment to drive the HVAC equipment between multiple positions; collecting internal actuator data characterizing an operation of the actuator, the internal actuator data comprising a measured or calculated value of an operational variable; predicting a time at which the value of the operational variable will reach a failure threshold; and identifying the predicted time at which the value of the operational variable will reach the failure threshold as a predicted time at which the HVAC equipment failure will occur.

15 . The method of claim 14 , further comprising:
providing control signals to the actuator from a contro

Assignees

• Johnson Controls Tech Co

Inventors

• Brownie Michael R
• Romanowich Gary A
• Alexander Robert K
• Vandermause Nathan J

Classifications

• F24F11/32

  Responding to malfunctions or emergencies · CPC title

• G05B23/0243

  model based detection method, e.g. first-principles knowledge model · CPC title

• G05B23/0275 Primary

  Fault isolation and identification, e.g. classify fault; estimate cause or root of failure · CPC title

• G05B23/0283

  Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] (preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06) · CPC title

• G01M99/008

  by doing functionality tests · CPC title