Integrating point cloud scans, image data, and total station data from a surveying instrument into one adjustment

Patent metadata

Field	Value
Publication number	US-10048068-B2
Application number	US-201615194699-A
Country	US
Kind code	B2
Filing date	Jun 28, 2016
Priority date	Jun 28, 2016
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

A method to integrate all observations, e.g., surveying data in the form of total station data, images, and point clouds) from a surveying instrument that functions as a total station, a camera(s), and a scanner. The method provides an overall adjustment to maximize the accuracy of the adjustment by using all three types of available surveying data, and the method may be labeled an overall adjustment or integrated network adjustment to provide accurate station or instrument position data for a geodatabase for a surveyed site. The overall adjustment method allows all three types of surveying data to influence the results of the adjustment, and this achieved by generating a small number of virtual observations from the image and scan data that are of a form that allows them to be combined with or considered concurrently with the real observations from the total station as part of a single network adjustment.

First claim

We claim:

1. A method for performing an integrated adjustment of data collected by a surveying instrument operable to gather differing data types, comprising:
storing in memory a set of total station observations for a physical site, image data for the site, and scan data for the site; and
with a processor, executing computer-executable code defining an overall adjustment to:
retrieve the total station observations, the image data, and the scan data;
perform a bundle adjustment of the image data;
after the bundle adjustment, generate a set of virtual observations from the image data;
perform a registration adjustment of the scan data;
after the registration adjustment, generate a set of virtual observations from the scan data; and
perform a single network adjustment on the total station observations, the virtual observations from the image data, and the virtual observations from the scan data, and

wherein the overall adjustment program further assigns, prior to the performing of the single network adjustment, weighting to the virtual observations from the image data and to the virtual observations from the image data from the scan data, and
wherein the weighting is based on a total number of observations in the image data and the scan data, respectively.

2. The method of claim 1 , wherein the single network adjustment provides positions of the surveying instrument based on the set of total station observations, the image data, and scan data.

3. The method of claim 1 , wherein the bundle adjustment comprises computing a six-dimensional (6D) pose and a covariance matrix based on the image data and the registration adjustment comprises computing a six-dimensional (6D) pose and a covariance matrix based on the scan data.

4. The method of claim 1 , wherein the set of virtual observations from the scan data includes less than ten observations and wherein the set of virtual observations from the image data includes less than ten observations.

5. The method of claim 4 , wherein the set of virtual observations from the scan data includes at least four observations and wherein the set of virtual observations from the image data includes at least four observations.

6. The method of claim 1 , wherein the virtual observations in the set of virtual observations from the image data comprise angles-only observations and wherein the virtual observations in the set of virtual observations from the scan data comprise angles and distance observations.

7. The method of claim 1 , wherein the virtual observations are generated by computing a centroid of stations for the surveying instrument during collection of the scan data and the image data, positioning a sphere relative to the centroid, and choosing a set of points on the surface of the sphere.

8. The method of claim 7 , wherein the set of points are selected to maximize a minimum distance from each of the points to one of the stations.

9. A method for adjusting positional data gathered with a surveying instrument, comprising:
performing a photogrammetry bundle adjustment for image data for a site gathered by the surveying instrument positioned at a plurality of stations;
performing a scan-to-scan registration for point cloud data gathered by the surveying instrument positioned at the plurality of stations;
generating a first set of virtual observations using output of the photogrammetry bundle adjustment;
generating a second set of virtual observations using output of the scan-to-scan registration; and
performing a network adjustment on a combination of the first and second sets of virtual observations,
wherein the combination processed in the network adjustment further comprises total station observations obtained at the plurality of stations via operation of the surveying instrument, and
wherein the virtual observations are configured to have a data type compatible with the total station observations.

10. The method of claim 9 , wherein the network adjustment comprises a least squares adjustment.

11. The method of claim 9 , wherein the photogrammetry bundle adjustment comprises computing a six-dimensional (6D) pose and a covariance matrix based on the image data and the scan-to-scan registration comprises computing a six-dimensional (6D) pose and a covariance matrix based on the point cloud data.

12. The method of claim 9 , further comprising assigning, prior to the performing of the network adjustment, weighting to the virtual observations from the image data and to the virtual observations from the image data from the scan data and wherein the weighting is calculated based on a total number of observations in the image data and the point cloud data, respectively.

13. The method of claim 9 , wherein the first and second sets each include a number of observations in the range of 5 to 9.

14. The method of claim 9 , wherein the virtual observations are generated by computing a centroid of the stations, positioning a sphere relative to the centroid, and choosing a set of points on the surface of the sphere and wherein the set of points are selected to maximize a minimum distance from each of the points to one of the stations.

15. A system for processing surveying data to enhance positional accuracy, comprising:
a surveying instrument including a total station, at least one camera, and a scanner, wherein the surveying instrument is operable to collect, at a plurality of stations, a set of total station observations with the total station, images with the at least one camera, and scan data with the scanner; and
a server providing an overall adjustment module that functions to:
generate a first set of virtual observations from the image data;
generate a second set of virtual observations from the scan data;
weight the virtual observations in the first and second sets based on total numbers of observations in the image data and the scan data, respectfully; and
perform an adjustment on a combination of the set of total station observations, the weighted first set of virtual observations from the image data, and the weighted second set of the virtual observations from the scan data.

16. The system of claim 15 , wherein the overall adjustment module performs a bundle adjustment on the image data prior to the generating of the first set of virtual observations and wherein the overall adjustment module performs a scan-to-scan adjustment on the scan data prior to the generating of the second set of virtual observations.

17. The system of claim 15 , wherein the total station observations and the virtual observations each include a 6D pose and a [6×6] covariance matrix.

18. A method for performing an integrated adjustment of data collected by a surveying instrument operable to gather differing data types, comprising:
storing in memory a set of total station observations for a physical site, image data for the site, and scan data for the site; and
with a processor, executing computer-executable code defining an overall adjustment to:
retrieve the total station observations, the image data, and the scan data;
perform a bundle adjustment of the image data;
after the bundle adjustment, generate a set of virtual observations from the image data;
perform a registration adjustment of the scan data;
after the registration adjustment, generate a set of virtual observations from the scan data; and
perform a single network adjustment on the total station observations, the virtual observations from the image data, and the virtual observations from the scan data,

wherein the set of virtual observations from the s

Assignees

• Trimble Navigation Ltd
• Trimble Inc

Inventors

• Brown Troy
• Boucherat Arnaud
• Chaperon Thomas G

Classifications

• G06T7/50

  Depth or shape recovery · CPC title

• G01C1/04 Primary

  combined with cameras · CPC title

• G06T2207/10028

  Range image; Depth image; 3D point clouds · CPC title

• G06T7/593

  from stereo images · CPC title

• G06T2207/30244

  Camera pose · CPC title