Real-time pressure-volume curve generation for a hydraulic system
A system and method for generating a pressure-volume curve for a hydraulic system in a vehicle. The system includes a plunger coupled to the hydraulic system, a pressure sensor configured to detect a pressure of the hydraulic system, and an electronic controller configured to access a prior pressure-volume curve from a memory, generate a signal to move the plunger, receive a pressure from the pressure sensor, generate a new pressure-volume curve based upon the received pressure and a position of the plunger, compare the new pressure-volume curve to the prior pressure-volume curve, in response to the new pressure-volume curve and the prior pressure-volume curve differing by at least a threshold value, replace the prior pressure-volume curve with the new pressure-volume curve in the memory, and actuating the hydraulic system based upon the stored pressure-volume curve.
1. A system ( 100 ) for generating a pressure-volume curve for a hydraulic system ( 110 ) in a vehicle ( 105 ), the system ( 100 ) comprising:
a plunger ( 115 ) coupled to the hydraulic system ( 110 ),
a pressure sensor ( 120 ) configured to detect a pressure of the hydraulic system ( 110 ), and
an electronic controller ( 130 ) configured to
access a prior pressure-volume curve from a memory ( 215 ),
generate a signal to move the plunger ( 115 ),
receive a pressure from the pressure sensor ( 120 ),
generate a new pressure-volume curve based upon the received pressure and a position of the plunger ( 115 ),
compare the new pressure-volume curve to the prior pressure-volume curve,
in response to the new pressure-volume curve and the prior pressure-volume curve differing by at least a threshold value, replace the prior pressure-volume curve with the new pressure-volume curve in the memory ( 215 ), and
actuate the hydraulic system ( 110 ) based upon the stored pressure-volume curve.
2. The system ( 100 ) of claim 1 , wherein the plunger ( 115 ) is moved at a constant rate.
3. The system ( 100 ) of claim 1 , wherein the volume is calculated based upon the plunger position and a plunger surface area.
4. The system ( 100 ) of claim 1 , wherein the new pressure-volume curve is compared to the prior pressure-volume curve when the pressure of the hydraulic system ( 110 ) is above a pressure threshold.
5. The system ( 100 ) of claim 1 , wherein the new pressure-volume curve is compared to the prior pressure-volume curve at a plurality of pressure points.
6. The system ( 100 ) of claim 1 , wherein a volume at a pressure value of the prior pressure-volume curve is subtracted from a volume of the new pressure-volume curve at the same pressure value and compared to the threshold value.
7. The system ( 100 ) of claim 1 , wherein the memory ( 215 ) is an electrically erasable programmable read-only memory (EEPROM).
8. The system ( 100 ) of claim 1 , further comprising a temperature sensor ( 125 ) to detect a temperature of the hydraulic system ( 110 ).
9. The system of claim 8 , wherein the electronic controller ( 130 ) is further configured to utilize the temperature to generate the pressure-volume curve.
10. A system ( 100 ) for generating a pressure-volume curve for a hydraulic system ( 110 ) in a vehicle ( 105 ), the system ( 100 ) comprising:
a plunger ( 115 ) coupled to the hydraulic system ( 110 ),
a pressure sensor ( 120 ) configured to detect a pressure of the hydraulic system ( 110 ), and
an electronic controller ( 130 ) configured to
access a prior pressure-volume curve from a memory ( 215 ),
generate a signal to move the plunger ( 115 ),
receive a pressure from the pressure sensor ( 120 ),
generate a new pressure-volume curve based upon the received pressure and a position of the plunger ( 115 ),
compare the new pressure-volume curve to the prior pressure-volume curve,
in response to the new pressure-volume curve and the prior pressure-volume curve differing by at least a threshold value, replace the prior pressure-volume curve with the new pressure-volume curve in the memory ( 215 ), and
actuate the hydraulic system ( 110 ) based upon the stored pressure-volume curve, wherein the vehicle ( 105 ) is at a standstill.
11. A method ( 400 ) for generating a pressure-volume curve for a hydraulic system ( 110 ) in a vehicle ( 105 ), the method ( 400 ) comprising:
accessing, using an electronic controller ( 130 ), a prior pressure-volume curve from a memory ( 215 ),
generating, using the electronic controller ( 130 ), a signal to move a plunger ( 115 ) coupled to the hydraulic system ( 110 ),
receiving, at the electronic controller ( 130 ), a pressure of the hydraulic system ( 110 ) from a pressure sensor ( 120 ),
generating, with the electronic controller ( 130 ), a new pressure-volume curve based upon the received pressure and a position of the plunger ( 115 ),
comparing, with the electronic controller ( 130 ), the new pressure-volume curve to the prior pressure-volume curve,
in response to the new pressure-volume curve and the prior pressure-volume curve differing by at least a threshold value, replacing, with the electronic controller ( 130 ), the prior pressure-volume curve with the new pressure-volume curve in the memory ( 215 ), and
actuating, with the electronic controller ( 130 ), the hydraulic system ( 110 ) based on the stored pressure-volume curve.
12. The method ( 400 ) of claim 11 , wherein the method ( 400 ) is performed while the vehicle ( 105 ) is at a standstill.
13. The method of claim 11 , wherein the new pressure-volume curve is compared to the prior pressure-volume curve at a plurality of pressure points.
14. The method of claim 13 , wherein a volume of the prior pressure-volume curve at each of the plurality of pressure points is subtracted from a volume of the new pressure-volume curve and compared to the threshold value.
15. The method of claim 11 , further comprising receiving, with the electronic controller ( 130 ), a temperature from a temperature sensor ( 125 ), wherein generating the new pressure-volume curve further includes utilizing the temperature to generate the new pressure-volume curve.
16. The method of claim 11 , wherein the plunger is moved at a constant rate.
17. The method of claim 11 , wherein the volume is calculated based upon the plunger position and a plunger surface area.
18. The method of claim 11 , wherein the new pressure-volume curve is compared to the prior pressure-volume curve when the pressure of the hydraulic system is above a pressure threshold.
19. The method of claim 11 , wherein the memory is an electrically erasable programmable read-only memory (EEPROM).