BUILDING AUTOMATION SYSTEMS AND METHODS FOR CONTROLLING INTERACTING CONTROL LOOPS

• US 20080294291A1
• Filed: 05/22/2008
• Published: 11/27/2008
• Est. Priority Date: 05/24/2007
• Status: Abandoned Application

• Current Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Salsbury, Timothy
• Application Number:
  US12/125,843
• Publication Number:
  US 20080294291A1
• Time in Patent Office: Days
• US Class Current: 700/277
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/54 using one central controller connected to several sub-controllers
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values

Abstract

A method for maintaining a first climate control setpoint for a first building zone having an environment that is effected by a second building zone'"'"'s environment includes the steps of providing the first climate control setpoint to a first control loop configured to control the environment of the first building zone. The method further includes providing a second climate control setpoint to a second control loop configured to control the environment of the second building zone. The method yet further includes receiving information about the actual climate of the first building zone and the actual climate of the second building zone; and modifying the first climate control setpoint and the second climate control setpoint to compensate for interaction between the first control loop and the second control loop.

Claims

1. A method for maintaining a first climate control setpoint for a first building zone having an environment that is affected by a second building zone'"'"'s environment, comprising:

providing the first climate control setpoint to a first control loop configured to control the environment of the first building zone;

providing a second climate control setpoint to a second control loop configured to control the environment of the second building zone;

receiving information about the actual climate of the first building zone and the actual climate of the second building zone; and

modifying the first climate control setpoint and the second climate control setpoint to compensate for interaction between the first control loop and the second control loop.

2. The method of claim 1, further comprising:

determining a first error between the actual climate of the first building zone and the first climate control setpoint and a second error between the actual climate of the second building zone and the second climate control setpoint; and

calculating the amount of the modification for the first climate control setpoint and the second climate control setpoint based on the first error, the second error, the contribution of the second control loop to the first error, and the contribution of the first control loop to the second error.

3. The method of claim 2, wherein the calculation of the amount of the modification for the first climate control setpoint and the second climate control setpoint is further based on the contribution of the first control loop to the first error and the contribution of the second control loop to the second error.

4. The method of claim 1, further comprising:

storing the first climate control setpoint in a memory device prior to modification;

storing the second climate control setpoint in the memory device prior to modification; and

wherein the modification is based on a calculation configured achieve the stored first climate control setpoint in a future period of time and to achieve the stored second climate control setpoint in the future period of time.

5. A system for maintaining a climate control setpoint for a first building zone having a climate that is affected by a second building zone'"'"'s climate, comprising:

a first control loop configured to control the first environment of the building zone;

a second control loop configured to control the second environment of the building zone; and

a supervisory controller configured to receive information about the actual climate of the first building zone and the second building zone and to associate a previous climate control setpoint for the first building zone and a previous climate control setpoint for the second building zone with the information about the actual climate of the first building zone;

wherein the supervisory controller is configured to calculate a new climate control setpoint for the first building zone and a new climate control setpoint for the second building zone based on the information about the actual climate of the first building zone and the second building zone and the previous setpoints of the control loops, and wherein the supervisory controller is configured to provide the new climate control setpoint to the first control loop and the second control loop.

6. The system of claim 5, wherein the first control loop is a single-input single-output (SISO) control loop.

7. The system of claim 6, wherein the second control loop is a SISO control loop.

8. A method for maintaining a first climate control setpoint for a first building zone having a climate that is affected by a second building zone'"'"'s climate, comprising:

providing the first climate control setpoint to a first control loop configured to control the climate of the first building zone;

providing a second climate control setpoint to a second control loop configured to control the climate of the second building zone;

observing the behavior of the climate of the first building zone relative to the first climate control setpoint and the second climate control setpoint; and

sending a new first climate control setpoint to the first control loop and a new second climate control setpoint to the second control loop;

wherein the new first climate control setpoint and the new second climate control setpoint are determined based on the observation.

9. The method of claim 8, wherein the new first climate control setpoint and the new second climate control setpoint are calculated to compensate for determined interaction between the first control loop and the second control loop.

10. The method of claim 8, wherein the first control loop is a single-input and single-output (SISO) control loop.

11. The method of claim 10, wherein the second control loop is a single-input and single-output (SISO) control loop.

12. A supervisory controller configured to simulate a multi-variable climate control loop for a building zone by adjusting a first control signal to a first single-input single-output (SISO) control loop associated with the building zone and a second control signal to a SISO control loop associated with an nearby building zone, the building zone having a first sensor for measuring the climate variable intended to be controlled by the first SISO control loop and the adjacent building zone having a second sensor for measuring the climate variable intended to be controlled by the second control loop, supervisory controller comprising:

a processing circuit configured to;

read a target setpoint for the climate variable intended to be controlled by the first SISO control loop;

send the first control signal to the first SISO control loop;

send the second control signal to the second SISO control loop;

receive signals from the first sensor and second sensor;

calculate an adjustment to the first control signal and an adjustment to the second control signal, the adjustments based on the signals from the first sensor and the second sensor and the first control signal and the second control signal;

provide an adjusted first control signal to the first SISO control loop; and

provide an adjusted second control signal to the second SISO control loop.

13. The supervisory controller of claim 12, wherein the processing circuit comprises a processor and memory communicably coupled to the processor, the memory comprising computer code for completing the calculation.

14. The supervisory controller of claim 12, wherein the first sensor and the second sensor are one of temperature sensors or humidity sensors.

15. The supervisory controller of claim 12, wherein the first SISO control loop comprises a variable air volume box and a local controller for the variable air volume box, the local controller configured to the adjust the variable air volume box to maintain the setpoint commanded by the first control signal.

16. The supervisory controller of claim 15, wherein the second SISO control loop comprises a variable air volume box and a local controller for the variable air volume box, the local controller configured to the adjust the variable air volume box to maintain the setpoint commanded by the second control signal.

17. The supervisory controller of claim 12, wherein the calculation includes a function configured to compensate for the effect of the second SISO control loop on the first SISO control loop.

18. The supervisory controller of claim 17, wherein the function is further configured to compensate for the effect of the first SISO control loop on the second SISO control loop.

19. The supervisory controller of claim 12, wherein the supervisory controller is part of the first SISO control loop, the second SISO control loop, or a part of the first SISO control loop and the second SISO control loop.

20. The supervisory controller of claim 12, wherein the supervisory controller is a computer system upstream of the first SISO control loop and the second SISO control loop.

21. The supervisory controller of claim 12, wherein the supervisory controller is a system of distributed computing components.

22. A method for maintaining a first condition at a first target for the first condition using a first single-input single-output (SISO) control loop and for maintaining a second condition at a second target for the second condition using a second SISO control loop, the method comprising:

using a supervisory controller to adjust the inputs to the first SISO control loop and the second SISO control loop to account for interactions between the first SISO control loop and the second SISO control loop, the adjustment based on the targets.

23. The method of claim 22, wherein the inputs to the first SISO control loop and the second SISO control loop are setpoints stored in memory of the supervisory controller.