Method and apparatus for determining machine location

• US 6,711,838 B2
• Filed: 07/29/2002
• Issued: 03/30/2004
• Est. Priority Date: 07/29/2002
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Staub, Michael David, Keefer, Claude Wesley
• Primary Examiner(s): BATSON, VICTOR D
• Application Number:
  US10/206,199
• Publication Number:
  US 20040020083A1
• Time in Patent Office: 610 Days
• Field of Search: 373/48, 373/82, 371/95, 172/1, 172/2, 172/5, 172/6, 172/12, 701/50, 414/699, 414/694
• US Class Current: 37/348
• CPC Class Codes: E02F 9/26 Indicating devices E02F5/145 takes precedence

Abstract

A method is provided for determining the location of a work machine at a work site, where the work machine includes a house, a boom connected to the house, a stick connected to the boom, and a work implement connected to the house. Reference signals are received from an external reference source. The position of a point on the house is determined in response to the received signals. Information about the work machine is determined based on the position of the point on the house. The status of center-of-rotation (COR) information is updated. The system determines if an event has occurred. If an event is determined to have occurred, event reactions occur.

Claims

1. A method for determining the location of a work machine at a work site, the work machine including a house, a boom connected to the house, a stick connected to the boom, and a work implement connected to the stick, comprising:

receiving reference signals from an external reference source;

determining the position of a point on the house in response to the received signals;

determining information about the work machine based on a position of the point on the house;

updating a status of a center-of-rotation (COR) information;

determining if an event has occurred; and

if an event is determined, reacting to the event,

wherein the step of reacting to the event includes;

determining whether an updated COR is available; and

if an updated COR is available, processing the event.

2. The method of claim 1, wherein the step of processing the event includes:

storing the position of the point on the house;

storing loading information associated with one or more rotations of the house;

calculating COR information; and

determining position information about the work machine based on the stored position of the point on the house and the calculated COR information.

3. The method of claim 2, wherein the step of processing the event further includes:

determining the event is a loading event;

locating the region where the loading event occurred;

determining the material type associated with the load region; and

storing information about the load.

4. The method of claim 3, further including communicating the material type to an operator.

5. The method of claim 3, wherein the load information stored includes at least one of a load time, a load angle, and the material type.

6. The method of claim 2, wherein the step of processing the event further includes:

determining the event is a dumping event;

locating the center of a load region;

calculating a swing angle from the load region to a dumping site;

clearing the material type associated with the load; and

storing load information.

7. The method of claim 6, further including the step of changing a display on a display screen to reflect a dumping activity.

8. The method of claim 1, wherein the step of determining if an event has occurred includes:

monitoring a hydraulic pressure within the work machine; and

determining an event has occurred if the hydraulic pressure exceeds a predetermined value.

9. The method of claim 1, wherein the step of determining if an event has occurred includes:

monitoring a pressure switch within the work machine; and

determining an event has occurred if the pressure switch indicates an event.

10. The method of claim 1, further including:

determining if an updated COR is available;

if an updated COR is available, processing events in an events queue; and

if an updated COR is unavailable, queuing events in an events queue.

11. The method of claim 10, wherein the step of processing events in the events queue includes:

obtaining event information from the events queue;

obtaining a stored position of the point on the house associated with the event;

storing a current state of the work machine;

comparing the stored position of the point on the house associated with the event and the updated COR; and

if the comparison is within a threshold value, performing the steps of;

setting a state of the work machine to a state associated with the event based on the event information;

processing the event based on the event information; and

returning the work machine to the stored current state.

12. The method of claim 10, wherein the step of queuing events in the events queue includes:

storing event information associated with the event in the events queue; and

storing a position of the point on the house associated with the event in the events queue.

13. The method of claim 12, wherein the event information includes at least one of the type of event, position location information, and the time of the event.

14. An apparatus for determining the location of a work machine at a work site, comprising:

a house;

a boom connected to the house;

a stick connected to the boom;

a work implement connected to the stick;

a positioning system including a receiver connected to the house, the positioning system being configured to determine the location of the receiver in three dimensional space at a plurality of points as the house is rotated and to further determine the location and orientation of the work implement in response to the location of the plurality of points;

a sensor configured to identify an event; and

a processor, including a storage device in which a queue of events is stored, configured to determine the location of the receiver in three dimensional space at the time of an event and to process the event in relation to the location of the receiver and the location of the plurality of points.

15. The apparatus of claim 14, further including:

a storage device in which a site survey of the work site is stored; and

a display element for indicating the location of the work machine in the work site.

16. The apparatus of claim 14, wherein the sensor determines when the work machine is being loaded.

17. The apparatus of claim 14, wherein the sensor determines when the work machine is being dumped.

18. A method for determining the location of a work machine, having a calculated center of rotation (COR) information, when the work machine trams and rotates simultaneously, the method comprising:

determining when an event has occurred;

storing the calculated COR information upon determining that an event has occurred;

obtaining position information based on received reference signals from an external reference source; and

determining a current location of the work machine based on the stored COR information and the obtained position information.