Systems and methods for correcting detected temperature for a climate control system

Patent metadata

Field	Value
Publication number	US-11067306-B1
Application number	US-201916540925-A
Country	US
Kind code	B1
Filing date	Aug 14, 2019
Priority date	Aug 14, 2019
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

Methods and related systems for measuring a temperature with an onboard sensor of a device of a heating, ventilation, and air conditioning (HVAC) system are disclosed. In an embodiment, the method includes (a) changing a power state of the device from off to on, and (b) detecting a raw temperature with the sensor after (a). In addition, the method includes (c) determining a time offset along a predetermined time and temperature relationship for the device, and (d) calculating a temperature offset with the predetermined time and temperature relationship at the time offset. Further, the method includes (e) subtracting the temperature offset from the raw temperature.

First claim

What is claimed is:

1. A method of measuring a temperature with an onboard sensor of a device of a heating, ventilation, and air conditioning (HVAC) system, the method comprising:
(a) changing a power state of the device from off to on;
(b) detecting a raw temperature with the sensor after (a);
(c1) deriving a predetermined time and temperature relationship during a previous operation of the device before (a), wherein the predetermined time and temperature relationship comprises T F (1−e −t/τ ), wherein T F and τ are constant values, and t is time since powering on the device at (a);
(c2) determining a time offset along the predetermined time and temperature relationship for the device;
(d) calculating a temperature offset with the predetermined time and temperature relationship at the time offset; and
(e) subtracting the temperature offset from the raw temperature.

2. The method of claim 1 , wherein deriving the predetermined time and temperature relationship comprises deriving values for T F and τ during the previous operation of the device before (a).

3. The method of claim 2 , wherein (c2) comprises calculating the time offset with the relationship:

τ
⁢

ln
⁡

(

T
F

-
Δ

⁢
T

)

,

wherein ΔT is a difference between the raw temperature and a previous temperature detected by the sensor during the previous operation of the device before (a).

4. The method of claim 1 , comprising:
(f) determining that a time difference between (a) and the previous operation of the device before (a) is below a first predetermined value; or
(g) determining that a temperature difference between the raw temperature from (b) and a raw temperature detected by the sensor during the previous operation of the device before (a) is below a second predetermined value; and then
(h) subtracting a predetermined static temperature offset from the raw temperature as a result of the determination in (f) or the determination in (g).

5. The method of claim 1 , comprising:
(i) changing the power state of the device from off to on before (a);
(j) fitting one or more constant values of the predetermined time and temperature relationship with raw temperatures detected by the sensor per unit time; and
(k) utilizing the one or more fitted constant values within the time and temperature relationship to calculate a temperature offset.

6. The method of claim 5 , wherein (c2) comprises determining the time offset along the predetermined time and temperature relationship utilizing the one or more fitted constant values from (j); and
wherein (d) comprises calculating the temperature offset with the predetermined time and temperature relationship utilizing the one or more fitted constant values from (j) at the time offset.

7. The method of claim 5 , comprising:
(l) determining whether the one or more fitted constant values are within predetermined bounds before (k).

8. A non-transitory machine-readable medium including instructions that, when executed by a processor, cause the processor to:
(a) detect a raw temperature of the environment surrounding a device of a climate control system with an onboard sensor upon a change in a power state of the device from off to on;
(b1) derive a predetermined time and temperature relationship during a previous operation of the device before (a), wherein the predetermined time and temperature relationship comprises T F (1−e −t/τ ), wherein T F and τ are constant values, and t is time since the power state change of the device at (a);
(b2) determine a time offset along the predetermined time and temperature relationship for the device;
(c) calculate a temperature offset with the predetermined time and temperature relationship at the time offset; and
(d) subtract the temperature offset from the raw temperature.

9. The non-transitory machine-readable medium of claim 8 , wherein the instructions, when executed by the processor, further cause the processor to determine the time offset with the relationship:

τ
⁢

ln
⁡

(

T
F

-
Δ

⁢
T

)

,

wherein ΔT is a difference between the raw temperature and a raw temperature detected by the sensor during the previous operation of the device before (a).

10. The non-transitory machine-readable medium of claim 8 , wherein the instructions, when executed by the processor, further cause the processor to:
(e) determine that a time difference between (a) and the previous operation before (a) of the device is below a first predetermined value; or
(f) determine that a temperature difference between the raw temperature from (a) and a raw temperature detected by the sensor during the previous operation of the device before (a) is below a second predetermined value; and then
(g) subtract a predetermined static temperature offset from the raw temperature as a result of the determination in (e) or the determination in (f).

11. A thermostat for a heating, ventilation, and air conditioning (HVAC) system, the thermostat comprising:
a temperature sensor; and
a processor coupled to the temperature sensor, wherein the processor is configured to:
(a) detect a raw temperature of the environment surrounding the thermostat via the temperature sensor upon a change in a power state of the thermostat from off to on;
(b1) derive a predetermined time and temperature relationship during a previous operation of the thermostat before (a), wherein the predetermined time and temperature relationship comprises T F (1−e −t/τ ), wherein T F and τ are constant values, and t is time since the power state change of the thermostat at (a);

(b2) determine a time offset along the predetermined time and temperature relationship;
(c) calculate a temperature offset with the predetermined time and temperature relationship at the time offset; and
(d) subtract the temperature offset from the raw temperature.

12. The thermostat of claim 11 , wherein the processor is configured to determine the time offset with the relationship:

τ
⁢

ln
⁡

(

T
F

Assignees

• Trane Int Inc

Inventors

• Jaber Youssef A
• Smith Christopher Blake
• Rite Raymond Walter

Classifications

• G05D23/19

  characterised by the use of electric means {(G05D23/1393 takes precedence)} · CPC title

• F24F11/49 Primary

  ensuring correct operation, e.g. by trial operation or configuration checks · CPC title

• F24F11/61

  using timers · CPC title

• F24F2110/10

  Temperature · CPC title

• G05D23/32

  with provision for adjustment of the effect of the auxiliary heating device, e.g. a function of time · CPC title