Target instrument and surveying system

Patent metadata

Field	Value
Publication number	US-11536568-B2
Application number	US-201916558574-A
Country	US
Kind code	B2
Filing date	Sep 3, 2019
Priority date	Sep 6, 2018
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

A surveying system comprises a laser scanner for scanning a distance measuring light and for acquiring point cloud data and a target instrument having a target for reflecting the distance measuring light, wherein the target is a sphere having a known diameter, the laser scanner comprises a distance measuring module for projecting the distance measuring light, for receiving a reflected distance measuring light and for performing a distance measurement, an optical axis deflector which enables to two-dimensionally deflect the distance measuring light, and an arithmetic control module for controlling the optical axis deflector, and wherein the arithmetic control module is configured to perform a circular scan on a surface of the target by the optical axis deflector, to obtain a center of the target based on the point cloud data acquired by the circular scan and the diameter, and to measure a distance of the center of the target.

First claim

The invention claimed is:

1. A surveying system comprising a laser scanner for scanning a distance measuring light and for acquiring point cloud data and a target instrument having a target for reflecting said distance measuring light, wherein said target is a sphere having a known diameter, said laser scanner comprises a distance measuring module for projecting said distance measuring light, for receiving a reflected distance measuring light and for performing a distance measurement, an optical axis deflector which enables to two-dimensionally deflect said distance measuring light, and an arithmetic control module for controlling said optical axis deflector, and wherein said arithmetic control module is configured to perform a circular scan on a surface of said target by said optical axis deflector, to obtain a center of said target based on the point cloud data acquired by said circular scan and said diameter, and to measure a distance of the center of said target.

2. The surveying system according to claim 1 , wherein, with respect to said moving target, said optical axis deflector is configured to direct a center of said circular scan to the center of said target in such a manner that distance measurement values of an entire circumference obtained by said circular scan become equal to each other.

3. The surveying system according to claim 1 , wherein said target instrument further comprises a pole of which end indicates a measuring point and an air bubble tube provided on said pole, wherein the center of said target is positioned on an axis of said pole and is provided at a known position from the end of said pole, and wherein said laser scanner is configured to measure the center of said target and to carry out a measurement of said measuring point in a state where said pole is vertically supported.

4. The surveying system according to claim 1 , wherein said optical axis deflector includes a biaxial galvanometer mirror.

5. The surveying system according to claim 1 , wherein said optical axis deflector has a reference optical axis, said optical axis deflector comprises a pair of optical prisms rotatable around said reference optical axis and motors which individually and independently rotate said optical prisms, and wherein said arithmetic control module is configured to control a deflection of a distance measuring light by said optical axis deflector by controlling a rotating direction, a rotation speed and a rotation ratio of said pair of optical prisms, to perform a two-dimensional scan with a scan center optical axis as a center, and to control a deflection of said scan center optical axis with respect to said reference optical axis.

6. The surveying system according to claim 1 , wherein said arithmetic control module is configured to scan said distance measuring light in a scan pattern with at least one intersection or to scan said distance measuring light in a circular pattern by said optical axis deflector.

7. The surveying system according to claim 6 , wherein said arithmetic control module is configured to scan said distance measuring light by said optical axis deflector in such a manner that said intersection is formed on said target and a part of said scan pattern crosses said pole, to obtain the center of said target based on the point cloud data acquired by scanning said target, to carry out a measurement of said target, and to measure a tilt of said pole based on the center of said target and a distance measurement value obtained by crossing said pole.

8. The surveying system according to claim 6 , wherein said arithmetic control module is configured to carry out a sighting and a tracking of said target by said circular scan and to carry out a measurement of said target in a scan pattern with at least one intersection.

Assignees

• Topcon Corp

Inventors

• Nishita Nobuyuki

Classifications

• G01C9/24

  in closed containers partially filled with liquid so as to leave a gas bubble · CPC title

• G01S7/4817

  relating to scanning · CPC title

• G01C15/06

  Surveyors' staffs; Movable markers · CPC title

• G01S17/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G01C3/08 Primary

  Use of electric radiation detectors · CPC title