Automatic oil spill detection system

Patent metadata

Field	Value
Publication number	US-9506465-B2
Application number	US-201314045316-A
Country	US
Kind code	B2
Filing date	Oct 3, 2013
Priority date	Oct 5, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A method for detecting and isolation a leak in a hydraulic system having a supply pump serving at least one control valve is disclosed. In one embodiment, the control valve has multiple work sections. In step of the method, the hydraulic system is activated. In another step, an actuation command for at least one of the work sections is received, for example from a human-to-machine interface. Subsequently, the method may include generating a flow demand for the work sections for which an actuation command has been received. The method also includes the step of implementing at least one of a first, second, third, and fourth leak detection and isolation protocol to detect and isolate a leak between the pump and the control valve assembly, a leak between the reservoir and the control valve assembly and a leak between the at least one work circuit and the control valve assembly.

First claim

What is claimed is:

1. A method for detecting and isolating a leak in a hydraulic system having a supply pump serving at least one control valve having plurality of work sections, the method comprising the steps of:
(a) activating the hydraulic system;
(b) receiving an actuation command for at least one of the work sections;
(c) generating a flow demand for the work sections for which an actuation command has been received;
(d) implementing at least two of a first, second, and third leak detection and isolation protocols;
(e) the first leak detection and isolation protocol comprising the steps of:
i. monitoring a measured pump supply pressure;
ii. comparing the measured pump supply pressure to a pump supply pressure lower limit;
iii. generating a hydraulic system leak signal to isolate the control valve from the supply pump and to set the pump to a zero flow state when the measured pump supply pressure falls below the pump supply pressure lower limit;

(f) the second leak detection and isolation protocol comprising the steps of:
i. monitoring a measured flow consumption at an input and an output port for each of the hydraulic work sections;
ii. correlating the input flow consumption to the output flow consumption to create a monitored flow consumption correlation;
iii. comparing the monitored flow consumption correlation to a flow consumption correlation limit;
iv. generating a hydraulic system leak signal to set a zero flow demand signal to any work section having a monitored flow consumption correlation exceeding the flow consumption correlation limit for the work section;

(g) the third leak detection and isolation protocol comprising the steps of:
i. setting one or more work sections to a zero flow state and recording a differential pressure between a measured inlet and a measured outlet pressure;
ii. monitoring the inlet and outlet pressure for each of the work sections and calculating a monitored differential pressure;
iii. comparing the difference between the recorded differential pressure and the monitored differential pressure to a differential pressure change limit value;
iv. generating a hydraulic system leak signal to set a zero flow demand signal to each work section having a monitored differential pressure that exceeds the recorded differential pressure by more than the change limit value.

2. The method of claim 1 , wherein the step of implementing at least one of a first, second, and third leak detection and isolation protocol includes implementing the first and second leak detection and isolation protocols.

3. The method of claim 1 , wherein the step of implementing at least one of a first, second, and third leak detection and isolation protocol includes implementing the first and third leak detection and isolation protocols.

4. The method of claim 1 , wherein the step of implementing at least one of a first, second, and third leak detection and isolation protocol includes implementing the second and third leak detection and isolation protocols.

5. The method of claim 1 , wherein the step of implementing at least one of a first, second, and third leak detection protocol includes implementing the first, second, and third leak detection and isolation protocols.

6. The method of claim 5 , wherein the step of isolating the control valve from the supply pump includes closing a main pump shut off valve.

7. The method of claim 5 , wherein the step of isolating the control valve from the supply pump includes opening a pump bypass valve.

8. The method of claim 5 , wherein a hydraulic leak signal is generated when the monitored flow consumption correlation for the work section exceeds the flow consumption correlation limit for a predetermined period of time.

9. The method of claim 5 , wherein a hydraulic leak signal is generated when the monitored differential pressure exceeds the recorded differential pressure by more than the change limit value for a predetermined period of time.

10. The method of claim 1 , wherein the at least one control valve has at least three work sections.

11. The method of claim 1 , wherein the pump is a variable displacement pump.

12. The method of claim 11 , wherein the at least one control valve is configured to control the pump.

13. The method of claim 1 , wherein the hydraulic system further includes at least one controller having a non-transitory computer-readable storage medium comprising instructions that, when executed by a control unit of an electronic computing system, causes the control unit to execute the method of claim 1 .

14. A non-transitory computer-readable storage medium comprising instructions that, when executed by a control unit of an electronic computing system, causes the control unit to execute a method for detecting and isolating a leak in a hydraulic system having a supply pump serving at least one control valve having plurality of work sections, the method comprising the steps of:
(a) activating the hydraulic system;
(b) receiving an actuation command for at least one of the work sections;
(c) generating a flow demand for the work sections for which an actuation command has been received;
(d) implementing at least two of a first, second, and third leak detection and isolation protocols;
(e) the first leak detection and isolation protocol comprising the steps of:
i. monitoring a measured pump supply pressure;
ii. comparing the measured pump supply pressure to a pump supply pressure lower limit;
iii. generating a hydraulic system leak signal to isolate the supply pump from the control valve and to set the pump to a zero flow state when the measured pump supply pressure falls below the pump supply pressure lower limit;

(f) the second leak detection and isolation protocol comprising the steps of:
i. monitoring a measured flow consumption at an input and an output port for each of the hydraulic work sections;
ii. correlating the input flow consumption to the output flow consumption to create a monitored flow consumption correlation;
iii. comparing the monitored flow consumption correlation to a flow consumption correlation limit;
iv. generating a hydraulic system leak signal to set a zero flow demand signal to any work section having a monitored flow consumption correlation exceeding the flow consumption correlation limit for the work section;

(g) the third leak detection and isolation protocol comprising the steps of:
i. setting one or more work sections to a zero flow state and recording a differential pressure between a measured inlet and a measured outlet pressure;
ii. monitoring the inlet and outlet pressure for each of the work sections and calculating a monitored differential pressure;
iii. comparing the difference between the recorded differential pressure and the monitored differential pressure to a differential pressure change limit value;
iv. generating a hydraulic system leak signal to set a zero flow demand signal to each work section having a monitored differential pressure that exceeds the recorded differential pressure by more than the change limit value.

15. The non-transitory computer-readable storage medium claim 14 , wherein the step of implementing at least one of a first, second, and third leak detection and isolation protocol includes implementing the first and second leak detection and isolation protocols.

16. The non-transitory computer-readable storage medium of claim 14 , wherein the step of implementing at least one of a first, second, and third leak detection and isolation protocol includes implementing the first and third leak detection and isolation protocols.

Assignees

• Eaton Corp

Inventors

• Dybing Philip James
• Derung Andrew Justin

Classifications

• B60T11/323

  in hydraulic systems · CPC title

• F04B49/002 Primary

  Hydraulic systems to change the pump delivery · CPC title

• F15B2211/864

  Failure of an output member, e.g. actuator or motor failure · CPC title

• F15B2211/41563

  being connected to a pressure source and a return line · CPC title

• F15B20/005 Primary

  Leakage; Spillage; Hose burst · CPC title