Surveying apparatus and method of analyzing measuring data

• US 20050228614A1
• Filed: 03/11/2005
• Published: 10/13/2005
• Est. Priority Date: 09/14/2002
• Status: Active Grant

• Current Assignee: Trimble Jena GmbH (Trimble Inc.)
• Original Assignee: Trimble Jena GmbH (Trimble Inc.)
• Inventors: Usbeck, Christian, Kuehn, Olaf, Brueckner, Peter, Linss, Gerhard
• Granted Patent: US 7,246,034 B2
• Time in Patent Office: Days
• US Class Current: 702/179
• CPC Class Codes: G01B 21/045 Correction of measurements G01B9/02055 takes precedence
• CPC Class Codes: G06V 10/48 by mapping characteristic values of the pattern into a parameter space, e.g. Hough transformation

Abstract

Embodiments of the invention relate to a method for minimizing the influence of disturbing signals during calculation of shape elements from coordinate points. An aim of the embodiments of the invention is to exclude the coordinates which are not to be locally assigned to the desired shaped element from the calculation of the shaped element. Said aim is achieved by combining compensation methods for calculating the desired type of shaped element with recognition methods for the same type of shaped element and using the recognition methods for filtering the coordinate points that are relevant for calculating the shaped element out of all input coordinate points.

Claims

1. A method of analyzing measuring data, the method comprising:

inputting measuring data from a measuring device, the measuring data comprising a set of data values representing features of an object;

performing a recognition method on at least a subset of the data values for determining first parameters of a geometric shape element representing at least a portion of a feature of the object;

eliminating outliers from the set of data values, the outliers having a distance from the shape element having the determined first parameters greater than a first threshold; and

performing a first regression analysis on a set of remaining data values not including the outliers, for determining second parameters of the geometric shape element such that the shape element having the second parameters is a better representation of the portion of the at least one feature of the object than the shape element having the first parameters.

2. The method according to claim 1, wherein the recognition method comprises determining the first parameters of the geometric shape element such that a number of data values coinciding with the geometric shape element having the first parameters has a maximum value.

3. The method according to claim 1, wherein the recognition method comprises performing a Hough transformation based on the subset of data values.

4. The method according to claim 1, wherein the distance of the data values from the shape element having the first parameters is an Euclidean distance of the data values from the shape element having the first parameters.

5. The method according to claim 1, wherein the first threshold is a predetermined threshold.

6. The method according to claim 1, wherein the first threshold is determined based on an analysis of a distribution of values of the distances of the data values from the shape element having the determined first parameters.

7. The method according to claim 1, wherein the shape element comprises a straight line, a circle, an ellipse and a cylinder.

8. The method according to claim 1, wherein the shape element comprises a straight line and wherein the first parameters comprise a slope and an offset of the straight line.

16. A surveying apparatus comprising:

a camera;

a controller for receiving image data from the camera, wherein the controller is configured to generate measuring data to be analyzed from the image data and to perform the method of analyzing the measuring data according to claim 1.

17. The surveying apparatus according to claim 16, further comprising an input device for receiving a user selection of a type of the geometric shape element.

18. The method according to claim 17, wherein the shape element comprises a straight line, a circle, an ellipse and a cylinder.

19. The surveying apparatus according to claim 16, further comprising a display for displaying an image represented by the image data.

20. The surveying apparatus according to claim 19, further comprising an input device for selecting a portion of the displayed image, wherein the controller is configured to generate the measuring data to be analyzed from the image data representing the selected portion of the displayed image.

21. The surveying apparatus according to claim 16, further comprising an output device for receiving the determined parameters of the shape element.

22. A computer-readable carrier containing information representing a computer program adapted to cause a processing unit to execute the method of claim 1.

23. A computer system, comprising:

a processor; and

a program storage device readable by the computer system, tangibly embodying a program of instructions executable by the processor to perform the method according to claim 1.

9. A method of analyzing measuring data, the method comprising:

inputting measuring data from a measuring device, the measuring data comprising a set of data values representing a feature of an object;

performing a second regression analysis on at least a subset of the data values, for determining third parameters of a geometric shape element representing at least a portion of a feature of the object;

determining a value representing a quality of the representation of the portion of the feature of the object by the geometric shape element having the third parameters;

performing a recognition method on the subset of the data values for determining first parameters of the geometric shape element representing the portion of the feature of the object, wherein the recognition method is performed only if the value representing the quality of the representation exceeds a second threshold;

eliminating outliers from the set of data values, the outliers having a distance from the shape element having the determined first parameters greater than a first threshold; and

performing a first regression analysis on a set of remaining data values not including the outliers, for determining second parameters of the geometric shape element such that the shape element having the second parameters is a better representation of the portion of the feature of the object than the shape element having the first parameters.

10. The method according to claim 9, wherein the recognition method comprises determining the first parameters of the geometric shape element such that a number of data values coinciding with the geometric shape element having the first parameters has a maximum value.

11. The method according to claim 9, wherein the recognition method comprises performing a Hough transformation based on the subset of data values.

12. The method according to claim 9, wherein the value representing the quality of the representation of the portion of the feature of the object by the geometric shape element having the third parameters is determined based on distances of the data values from the shape element having the third parameters.

13. The method according to claim 12, wherein distances of the data values from the shape element having the third parameters are Euclidean distances of the data values from the shape element having the third parameters.

14. The method according to claim 12, wherein the second threshold is a predetermined threshold.

15. The method according to claim 12, wherein the second threshold is determined based on an analysis of a distribution of values of the distances of the data values from the shape element having the third parameters.

24. A surveying apparatus comprising:

a camera;

a controller for receiving image data from the camera, wherein the controller is configured to generate measuring data to be analyzed from the image data and to perform the method of analyzing the measuring data according to claim 9.

25. A computer-readable carrier containing information representing a computer program adapted to cause a processing unit to execute the method of claim 9.

26. A computer system, comprising:

a processor; and

a program storage device readable by the computer system, tangibly embodying a program of instructions executable by the processor to perform the method according to claim 9.