SYSTEM AND METHOD FOR PROVIDING POWER TO A HYDRAULIC SYSTEM

• US 20110295433A1
• Filed: 06/01/2010
• Published: 12/01/2011
• Est. Priority Date: 06/01/2010
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Evans, Timothy A.
• Application Number:
  US12/791,504
• Publication Number:
  US 20110295433A1
• Time in Patent Office: Days
• US Class Current: 700/282
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2091 Control of energy storage means for electrical energy, e.g. battery or capacitors energy recovery arrangements in hydraulic or pneumatic drives E02F9/2217
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method for providing power to a hydraulic system is disclosed. The method includes determining a hydraulic system power demand, determining an energy storage device power demand, and determining a desired parameter of a primary power source based on the hydraulic system power demand. The method further includes providing power to the hydraulic system as a function of the energy storage device power demand and the desired parameter.

Claims

1. A method for providing power to a hydraulic system, the method comprising:

determining a hydraulic system power demand;

determining an energy storage device power demand;

determining a desired parameter of a primary power source based on the hydraulic system power demand; and

providing power to the hydraulic system as a function of the energy storage device power demand and the desired parameter.

2. The method of claim 1, wherein determining the hydraulic system power demand includes receiving at least one of either a pressure associated with the hydraulic system or an electrical signal associated with the hydraulic system.

3. The method of claim 2, wherein determining the hydraulic system power demand includes receiving a pilot pressure associated with an input device operatively connected to the hydraulic system;

and determining the desired parameter of the primary power source includes determining a desired engine speed of an engine.

4. The method of claim 3, wherein determining the energy storage device power demand includes determining a state of charge of the energy storage device.

5. The method of claim 4, wherein providing power to the hydraulic system includes providing power in part from the engine and in part from the energy storage device.

6. The method of claim 5, the method further comprising:

comparing the desired engine speed to an actual engine speed; and

providing power to the hydraulic system in part from the energy storage device if the desired engine speed is greater than the actual engine speed.

7. The method of claim 6, the method further comprising:

comparing the state of charge to a charge threshold; and

providing power to the hydraulic system in part from the energy storage device if the state of charge is greater than the charge threshold.

8. The method of claim 7, the method further comprising:

providing power to the energy storage device from the engine if the desired engine speed is lower than the actual engine speed.

9. The method of claim 4, wherein providing power to the hydraulic system from the engine is a function of providing power to the hydraulic system from the energy storage device.

10. The method of claim 9, wherein providing power to the hydraulic system from the energy storage device results in the actual engine speed decreasing.

11. The method of claim 9, wherein providing power to the hydraulic system includes controlling a pump speed of a hydraulic pump operatively connected to the hydraulic system.

12. A system for providing power to a hydraulic system operatively connected to a primary power source, comprising:

a controller operatively connected to an energy storage device, the primary power source, and the hydraulic system, the controller adapted to;

determine a hydraulic system power demand;

determine an energy storage device power demand;

determine a desired parameter of a primary power source based on the hydraulic system power demand; and

provide power to the hydraulic system as a function of the energy storage device power demand and the desired parameter.

13. The system of claim 12, wherein determining the hydraulic system power demand includes receiving at least one of either a pilot pressure associated with or an electrical signal associated with an input device operatively connected to the hydraulic system.

14. The system of claim 12, wherein determining the desired parameter of a primary power source includes determining a desired engine speed of an engine, and determining the energy storage device power demand includes determining a state of charge of the energy storage device.

15. The system of claim 14, wherein the controller is further adapted to:

compare the desired engine speed to an actual engine speed; and

provide power to the hydraulic system in part from the energy storage device if the desired engine speed is greater than the actual engine speed.

16. The system of claim 15, wherein the controller is further adapted to:

compare the state of charge to a charge threshold; and

provide power to the hydraulic system in part from the energy storage device if the state of charge is greater than the charge threshold.

17. The system of claim 16, wherein the controller is further adapted to:

provide power to the energy storage device from the engine if the desired engine speed is lower than the actual engine speed.

18. The system of claim 17, wherein providing power to the hydraulic system from the engine is a function of providing power to the hydraulic system from the energy storage device, and providing power to the hydraulic system from the energy storage device reduces the actual engine speed.

19. A processor readable storage medium containing processor readable code for programming a processor to perform a method comprising:

determining a hydraulic system power demand by receiving a pilot pressure associated with an input device operatively connected to the hydraulic system;

determining a state of charge of an energy storage device;

determining a desired engine speed of an engine based in part on the pilot pressure; and

providing power to the hydraulic system in part from the engine and in part from the energy storage device as a function of the desired engine speed and the state of charge of the energy storage device.

20. A machine, comprising:

an engine;

an energy storage device;

a hydraulic system powered in part by the engine and in part by the energy storage device;

an input device operatively connected to the hydraulic system;

a controller operatively connected to the energy storage device, the engine, and the hydraulic system, the controller adapted to;

determine a hydraulic system power demand by receiving a pilot pressure associated with the input device;

determine a state of charge of the energy storage device;

determine a desired engine speed of the engine based in part on the pilot pressure; and

provide power to the hydraulic system in part from the engine and in part from the energy storage device as a function of the desired engine speed and the state of charge of the energy storage device.