Method and system for determining the relationship between a laser plane and an external coordinate system

• US 5,935,183 A
• Filed: 05/20/1996
• Issued: 08/10/1999
• Est. Priority Date: 05/20/1996
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Sahm, William C., Harrod, Gregory R.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US08/650,748
• Time in Patent Office: 1,177 Days
• Field of Search: 701/49-50, 701/213, 701/214, 701/215, 701/216, 37/347-348, 342/357, 172/4.5, 172/1, 172/9
• US Class Current: 701/50
• CPC Class Codes: E01C 19/006 by laser or ultrasound
• CPC Class Codes: E02F 3/842 using electromagnetic, optical or photoelectric beams, e.g. laser beams
• CPC Class Codes: E02F 3/847 using electromagnetic, optical or acoustic beams to determine the blade position, e.g. laser beams
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/009 Transmission of differential positioning data to mobile
• CPC Class Codes: G01S 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49

Abstract

A method and system to determine the relationship between a laser plane and an external coordinate system using a mobile machine with a work implement is provided. The laser plane is intersected at three points by a laser receiver installed on a mast attached to the work implement. A position determining antenna located a known distance on the mast from the laser receiver is used to determine external coordinates at the position determining antenna point. An equation for the laser plane in external coordinate terms is determined based on the three external position coordinates and the known distance between the external coordinate system plane and the laser plane.

Claims

1. A method for determining the relationship between a laser plane and an external coordinate system using a mobile machine with a work implement, comprising;

moving the work implement such that the laser plane intersects a laser detecting means mounted on the work implement and responsively generating an intersection signal;

receiving an external reference position signal from an external coordinate system position sensing means connected to the work implement, respectively;

leveling said work implement while maintaining intersection with the laser plane; and

, defining an equation of the laser plane in terms of the external coordinate system as a function of the external reference position signal.

2. A method as set forth in claim 1, further comprising the step of leveling said work implement with respect to one of the external coordinate system and the laser plane.

3. A method as set forth in claim 1, wherein the step of leveling said work implement further comprises the step of leveling said work implement with respect to the laser plane.

4. A method as set forth in claim 3, wherein the step of leveling said work implement further comprises:

determining a perpendicular work implement orientation relative to the laser plane; and

determining a parallel work implement orientation relative to the laser plane.

5. A method as set forth in claim 1, wherein the step of leveling said work implement further comprises the step of leveling said work implement with respect to the external coordinate system.

6. A method as set forth in claim 5 wherein the step of leveling said work implement further comprises the steps of:

determining a vertical blade orientation relative to the external coordinate system; and

determining a horizontal blade orientation relative to the external coordinate system.

7. A method, as set forth in claim 1, further comprising the steps of:

receiving a plurality of said intersection signals and a plurality of said external reference position signals

comparing said plurality of said intersection signal and said plurality of said external reference position signals.

8. A method, as set forth in claim 7, wherein the step of comparing said plurality of said intersection signals and said external reference position signals includes determining a constant offset between an elevation component of said intersection signals and said external reference position signals.

9. A method, as set forth in claim 7, wherein the step of comparing said plurality of said intersection signals and said external reference position signals includes determining a variable offset between an elevation component of said intersection signals and said external reference position signals.

10. A system for determining the relationship between a laser plane and an external coordinate system using a mobile machine with a work implement, comprising:

external coordinate system position sensing means for determining the position of the work implement in external coordinate system coordinates and responsively producing an external reference position signal;

laser detecting means for detecting intersection with the laser plane and responsively producing an intersection signal; and

controlling means for receiving said intersection signal and said external reference position signal and responsively defining an equation of the laser plane in terms of the external coordinate system as a function of the external reference position signal.