Methods and systems for controlling a vehicle air conditioner using a pressure sensor located within a compressor

Patent metadata

Field	Value
Publication number	US-10041552-B2
Application number	US-201514801523-A
Country	US
Kind code	B2
Filing date	Jul 16, 2015
Priority date	Jul 16, 2015
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

Methods and systems are provided for adjusting operation of an automotive air conditioning system including a pressure sensor positioned within a compression chamber. In one example, a method may include adjusting operation of the air conditioning system based on one or more parameters of a compressor operation including a compressor inlet pressure, a compressor outlet pressure, and a compressor speed, that are determined based on output from the pressure sensor positioned within the compression chamber.

First claim

The invention claimed is:

1. A method for a vehicle air conditioning system, comprising:
disengaging a compressor clutch in response to a compressor inlet pressure below a first threshold pressure; and
increasing a condenser fan speed in response to a compressor outlet pressure above a second threshold pressure, wherein both the compressor inlet and outlet pressures are estimated from a pressure sensor located within a compression chamber of a compressor by isolating a low pressure component from a high pressure component of a pressure sensor output.

2. The method of claim 1 , wherein isolating the low-pressure component from the high-pressure component is performed on a pressure sensor output obtained over a duration, the duration based on a number of compressor cycles.

3. The method of claim 2 , wherein the low-pressure component is based on the pressure sensor output indicated during an intake stroke of a piston, and wherein the high-pressure component is based on the pressure sensor output indicated during a discharge stroke of the piston.

4. The method of claim 3 , wherein the low-pressure component is further based on the pressure sensor output indicated during a first window during the intake stroke of the piston, the first window occurring when a suction valve of a cylinder including the piston is open and a discharge valve of the cylinder is closed; and wherein the low-pressure component is further based on the pressure sensor output indicated during a second window during the discharge stroke of the piston, the second window occurring when the suction valve is closed and the discharge valve is open.

5. The method of claim 4 , wherein estimating the compressor inlet pressure further includes averaging the low-pressure component isolated over the number of compressor cycles; and wherein estimating the compressor outlet pressure further includes averaging the high-pressure component isolated over the number of compressor cycles.

6. The method of claim 1 , wherein estimating the compressor inlet pressure further includes detecting a minimum pressure from the isolated low-pressure component during each compressor cycle, and estimating the compressor outlet pressure further includes detecting a maximum pressure from the isolated high-pressure component during each compressor cycle.

7. The method of claim 1 , further comprising disengaging the compressor clutch in response to the compressor outlet pressure above a third threshold pressure; and wherein the first threshold pressure is less than the second threshold pressure, and the second threshold pressure is less than the third threshold pressure.

8. The method of claim 1 , further comprising estimating a speed of the compressor based on an output of the pressure sensor.

9. The method of claim 8 , further comprising determining clutch engagement based on the speed of the compressor above a threshold speed; and indicating a slippage condition of the compressor clutch responsive to a difference between an expected compressor speed and the estimated speed of the compressor greater than a threshold, the expected compressor speed based on a speed of an energy conversion device driving the compressor.

10. A method for a vehicle air conditioning system, comprising:
adjusting an air conditioning control parameter based on an inlet pressure of a refrigerant entering a compressor estimated based on one or more pressure indications of a pressure sensor indicated within a first window of a rotation period of a compressor cycle; and
adjusting a different air conditioning control parameter based on an outlet pressure of the refrigerant exiting the compressor estimated based on one or more pressure indications of the pressure sensor measured within a second window of the rotation period, wherein the pressure sensor is located within a compression chamber of the compressor, wherein estimating the inlet pressure includes determining a lowest pressure during the first window during each compressor cycle for a threshold number of compressor cycles and computing a first average of the lowest pressures, and wherein estimating the outlet pressure includes determining a highest pressure during the second window during each compressor cycle for the threshold number of compressor cycles and computing a second average of the highest pressures.

11. The method of claim 10 , wherein estimating the inlet pressure includes averaging one or more pressure indications within the first window.

12. The method of claim 11 , wherein estimating the outlet pressure includes averaging one or more pressure indications within the second window.

13. The method of claim 12 , wherein the first window occurs during an inlet stroke of a compressor piston between a first crank angle degree and a second crank angle degree, and wherein the second window occurs during a discharge stroke of the compressor piston between a third crank angle degree and a fourth crank angle degree.

14. The method of claim 10 , wherein adjusting the air conditioning control parameter includes reducing a current supplied to an electromagnetic compressor clutch to disengage the compressor clutch in response to the inlet pressure below a first threshold pressure; and wherein adjusting the different air conditioning control parameter includes increasing a condenser fan speed in response to the outlet pressure above a second threshold pressure, the second threshold pressure greater than the first threshold pressure.

15. An air conditioning system of a vehicle, comprising:
an energy conversion device;
an air conditioner compressor including a cylinder, the cylinder including a compression chamber, a piston, a suction valve, and a discharge valve;
a pressure sensor located within the compression chamber of the cylinder; and
a controller configured with instructions stored in non-transitory memory that, when executed, cause the controller to:
disengage a compressor clutch in response to a compressor inlet pressure below a first threshold pressure; and
increase a condenser fan speed in response to a compressor outlet pressure above a second threshold pressure, wherein both the compressor inlet and outlet pressures are estimated from the pressure sensor by isolating a low pressure component from a high pressure component of a pressure sensor output.

Assignees

• Ford Global Tech Llc

Inventors

• Ulrey Joseph Norman
• Pursifull Ross Dykstra

Classifications

• B60H1/3222

  characterised by the compressor driving arrangements, e.g. clutches, transmissions or multiple drives (B60H1/3208, B60H1/3226 take precedence) · CPC title

• B60H1/3205 Primary

  Control means therefor · CPC title

• B60H2001/3277

  to control the air flow · CPC title

• F16D48/00 Primary

  External control of clutches · CPC title

• B60H2001/325

  of the refrigerant at a compressing unit · CPC title