Measurement method for a surface-measuring measuring machine

Patent metadata

Field	Value
Publication number	US-11454499-B2
Application number	US-201113636628-A
Country	US
Kind code	B2
Filing date	Mar 21, 2011
Priority date	Mar 26, 2010
Publication date	Sep 27, 2022
Grant date	Sep 27, 2022

Abstract

Measurement method where a code projection which is dependent on a three-dimensional position of a code carrier relative to a sensor arrangement is generated on a sensor arrangement, and at least part of the code projection is captured. An angular position of the code carrier with reference to the defined axis of rotation is ascertained and a current measurement position of the measurement component relative to a base is determined, wherein, a position value for at least one further degree of freedom of the code carrier relative to the sensor arrangement is ascertained on the basis of the code projection and is taken into account to determine the current measurement position, and a relative position of the connecting element with respect to the holder and/or the deformation thereof is determined from the position value in the form of a change in shape or size.

First claim

What is claimed is:

1. A method for determining a measurement position of a surface-measuring measuring machine measuring a surface, the surface-measuring measuring machine comprising:
a base;
a measurement component for producing and maintaining a contact-making or contactless measurement connection to the surface to be measured, wherein the measurement component is connected to the base by at least one connection element;
at least one rotary encoder, which detects a rotation of the at least one connection element with respect to a receptacle and in each case has a code carrier and a sensor arrangement, wherein code carrier and sensor arrangement are rotatable with respect to one another about a defined axis of rotation as a first degree of freedom, wherein on the basis of a code projection on the sensor arrangement, said code projection being dependent on the three-dimensional position of the code carrier relative to the sensor arrangement, a rotational position relative to the defined axis of rotation and a position value for at least one further degree of freedom of the code carrier relative to the sensor arrangement for the at least one rotary encoder are determinable, wherein the position value is usable to determine a relative position of the connection element with respect to the receptacle; and
an evaluation unit;
wherein the method comprises:
determining with the evaluation unit a measurement position of the measurement component relative to the base using the rotational position of the at least one rotary encoder and the relative position,
wherein the rotary encoder has at least two code carriers, which are rotatable about the same axis of rotation and are arranged at a distance from one another in a direction of the axis of rotation, and a position value is determined for each of the two code carriers on the basis of the respective code projection, wherein the combination of the position values of the two code carriers is used to determine a relative position of the connection element with respect to the receptacle, therein determine a change in length of the common axis or of a housing of the connection element and/or a flexure and/or a total movement of the connection element.

2. The method as claimed in claim 1 , wherein:
a deflection of the code carrier from a rest position in a radial direction relative to the axis of rotation; and/or
a deflection of the code carrier from a rest position in the direction of the axis of rotation; and/or
a tilting of the code carrier from a rest position relative to the sensor arrangement are/is determined as the position value.

3. The method as claimed in claim 1 , wherein rotational position, deflection and tilting and thus the position of the code carrier relative to the sensor arrangement in six degrees of freedom are determined for the at least one rotary encoder.

4. The method as claimed in claim 1 , wherein for the at least one rotary encoder a division into deformation- and relative-position-governed portions is effected on the basis of the orientation of a further connection element connected to the receptacle.

5. The method as claimed in claim 1 , wherein for at least one second rotary encoder the rotational position thereof and the position value thereof are determined and taken into account when determining a spatial position of the measurement component.

6. The method as claimed in claim 5 , wherein the measurement position is determined on the basis of the spatial position of the connection elements, said spatial position being derived exclusively by means of the rotational positions and position values of the at least two rotary encoders.

7. The method as claimed in claim 1 , wherein the determined relative position corresponds to the further degree of freedom of the code carrier.

8. The method as claimed in claim 1 , wherein the contactless measurement connection to the surface to be measured is an optical contactless measurement connection to the surface to be measured.

9. A coordinate measuring machine comprising an articulated arm for determining a measurement position, wherein the articulated arm has at least a first end as base and a second end having a measurement component for producing and maintaining a contact-connecting or contactless measurement connection to a surface to be measured, wherein the coordinate measuring machine is configured to determine the measurement position as in the method according to claim 1 .

10. A measurement method for a surface-measuring measuring machine, comprising:
a base;
a measurement component for producing and maintaining a contact-making or contactless measurement connection to a surface to be measured, wherein the measurement component is connected to the base by at least one connection element;
at least one rotary encoder, which detects a rotation of the at least one connection element with respect to a receptacle and in each case has a code carrier and a sensor arrangement, wherein code carrier and sensor arrangement are rotatable with respect to one another about a defined axis of rotation as a first degree of freedom; and
an evaluation unit;
wherein the method comprises:
generating a code projection on the sensor arrangement, said code projection being dependent on the three-dimensional position of the code carrier relative to the sensor arrangement, and detecting at least part of the code projection;
determining with the rotary encoder a rotational position relative to the defined axis of rotation of the code carrier on the basis of the code projection;
determining a position value for at least one further degree of freedom of the code carrier relative to the sensor arrangement for the at least one rotary encoder on the basis of the code projection, and using the position value to determine a relative position of the connection element with respect to the receptacle;
determining with the evaluation unit a current measurement position of the measurement component relative to the base using the rotational position of the at least one rotary encoder and the relative position,
wherein the rotary encoder has at least two code carriers, which are rotatable about the same axis of rotation and are arranged at a distance from one another in a direction of the axis of rotation, and a position value is determined for each of the code carriers on the basis of the respective code projection, wherein the combination of the position values of the two code carriers is used to determine a relative position of the connection element with respect to the receptacle, therein to determine a change in length of the common axis or of a housing of the connection element and/or a flexure and/or a total movement of the connection element.

11. The method as claimed in claim 10 , wherein:
a deflection of the code carrier from a rest position in a radial direction relative to the axis of rotation; and/or
a deflection of the code carrier from a rest position in the direction of the axis of rotation; and/or
a tilting of the code carrier from a rest position relative to the sensor arrangement are/is determined as the position value.

12. The method as claimed in claim 10 , wherein rotational position, deflection and tilting and thus the position of the code carrier relative to the sensor arrangement in six degrees of freedom are determined for the at least one rotary encoder.

13. The method as claimed in claim 10 , wherein for the at least one rotary encoder a division into deformation- and relative-position-governed portions is effected on the basis of the orientation of a further connection element connected to the receptacle.

14. The me

Assignees

• Lippuner Heinz
• Vokinger Urs
• Siercks Knut
• Leica Geosystems Ag

Inventors

• Lippuner Heinz
• Vokinger Urs
• Siercks Knut

Classifications

• G01D5/347 Primary

  using displacement encoding scales · CPC title

• G01B21/045 Primary

  Correction of measurements (G01B9/02055 takes precedence) · CPC title

• G01D5/3473

  Circular or rotary encoders · CPC title

• G01C1/00 Primary

  Measuring angles · CPC title

• G01B21/04

  by measuring coordinates of points · CPC title