Laser level selection

• US 6,324,455 B1
• Filed: 11/05/1998
• Issued: 11/27/2001
• Est. Priority Date: 11/05/1998
• Status: Expired due to Fees

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Jackson, Philip Richard
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): To, Tuan C
• Application Number:
  US09/186,582
• Time in Patent Office: 1,118 Days
• Field of Search: 701/50, 701/3, 356/147, 700/207, 37/97
• US Class Current: 701/50
• 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 1/7032 Transmitters
• CPC Class Codes: G01S 19/44 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method
• CPC Class Codes: G05D 1/0248 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS

Abstract

The apparatus and the system for precise vertical navigation of a grading machine in profile of a curved job site terrain is disclosed. The system includes an integrated satellite navigational receiver and a laser detector system. A plurality of laser systems generates a plurality of laser beams covering the curved job site terrain. The laser detector system mounted in the grading machine latches on a single laser beam at each location of the grading machine to obtain the precise vertical coordinate of the grading machine.

Claims

1. A system for guiding a grading machine in a job site comprising:

a satellite positioning system (SATPS) receiver configured to obtain the rough position coordinates X<sub>rough—

machine</sub>, Y<sub>rough—

machine</sub>, Z<sub>rough—

machine</sub>) of said grading machine;

a laser tracker connected to said SATPS receiver, said laser tracker configured to latch on a single laser beam at each location of said grading machine, each said laser beam being generated by a laser system, each said laser system being part of a plurality of laser systems covering said job site, each said laser beam providing a reference plane having a high accuracy vertical coordinate (Z_laser) at each said location (X<sub>rough—

machine</sub>, Y<sub>rough—

machine</sub>, Z<sub>rough—

machine</sub>) of said grading machine;

a signal system connected to said laser tracker and connected to said SATPS receiver;

said signal system further including;

an electronic design file configured to store a plurality of road design surfaces; and

an on-board computer;

wherein said on-board computer is configured to select a road design surface; and

wherein said on-board computer is configured to determine the rough position coordinates (X<sub>rough—

machine</sub>, Y<sub>rough—

machine</sub>, Z<sub>rough—

machine</sub>) for each location of said grading machine using said SATPS receiver; and

a software package TRIMDESIGN used for said selected road design to calculate an optimum K number of laser systems to place on said job site, K being an integer, and to calculate the optimum positions (X^opt_k-laser, Y^opt_k-laser, Z^opt_k-laser) for each said “

j”

-th laser system, j being an integer less than or equal to K;

wherein said plurality of K laser systems provides a plurality of K reference planes optimally covering said selected road design;

and wherein said on-board computer for said selected road design surface is configured to identify actual position coordinates (X_i-laser, Y_i-laser, Z_i-laser) for each said “

i”

-th laser system, i being an integer less than or equal to N, N being an integer;

and wherein said on-board computer for each location of said grading machine is configured to select a single optimum laser system that is used by said laser tracker to obtain the precise vertical coordinate (Z_laser) of said grading machine;

and wherein said signal system is configured to precisely guide said grading machine according to a given road design by generating a signal proportional to the difference between a design vertical coordinate (Z_design) and a real time vertical coordinate (Z_laser) at each said location (X<sub>rough—

machine</sub>, Y<sub>rough—

machine</sub>, Z<sub>rough—

machine</sub>) of said grading machine;

and wherein said on-board computer at each said ground position (X<sub>grade—

machine</sub>, Y<sub>grade—

machine</sub>) of said grading machine is configured to determine the cut or fill (Z_design-Z_laser) by comparing the road design vertical coordinate (Z_design) with said vertical coordinate Z_laser).