Method of finding a feature using a machine tool

Patent metadata

Field	Value
Publication number	US-9952028-B2
Application number	US-201715605377-A
Country	US
Kind code	B2
Filing date	May 25, 2017
Priority date	Apr 18, 2012
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A method of finding a feature of an object using an analog probe mounted on a machine tool. The method includes the analog probe and/or object following a course of motion which causes the analog probe's surface sensing region to traverse across the feature to be found a plurality of times while approaching the feature over successive traverses so as to ultimately arrive in a position sensing relationship with the feature so as to collect scanned measurement data about the feature along at least part of a traverse.

First claim

The invention claimed is:

1. A method of finding an object using an analogue probe mounted on a machine tool, the method comprising causing the analogue probe and/or object to follow a course of motion which is configured such that the analogue probe is initially sufficiently far away from the object such that the analogue probe is not in a position sensing relationship with anything and the course of motion is configured to cause the analogue probe's surface sensing region to traverse across the object to be found a plurality of times and approaching the object over successive traverses so as to ultimately arrive in a position sensing relationship with the object so as to collect scanned measurement data about the object along at least part of a traverse.

2. A method as claimed in claim 1 , comprising halting movement along the course of motion in response to it being determined that scanned surface measurement data in accordance with at least one criterion has been collected.

3. A method as claimed in claim 2 , in which the at least one criterion is a predetermined threshold indicative of the analogue probe obtaining a minimum level of data regarding the object.

4. A method as claimed in claim 2 , comprising halting movement at some point after scanned surface measurement data in accordance with the at least one criterion has been collected.

5. A method as claimed in claim 4 , in which the surface sensing region continues along its traverse after the scanned surface measurement data in accordance with the predetermined criterion has been collected, until a subsequent predetermined condition has been met.

6. A method as claimed in claim 5 , in which the subsequent predetermined condition is that the course of motion has reached a predetermined point.

7. A method as claimed in claim 6 , in which the predetermined point is that point at which the surface sensing region reaches an end of the traverse in which the first predetermined criterion was met.

8. A method as claimed in claim 2 , in which it is determined at predetermined intervals whether the analogue probe obtained scanned surface measurement data along the surface of the object.

9. A method as claimed in claim 8 , in which at the predetermined intervals, the analogue probe's output collected prior to the predetermined interval is analysed to determine whether the analogue probe obtained scanned object measurement data, prior to resumption of relative movement along the path.

10. A method as claimed in claim 1 , in which movement is halted immediately in response to it being determined that scanned surface measurement data in accordance with at least one second criterion has been collected.

11. A method as claimed in claim 10 , in which the at least one second criterion comprises a magnitude of data output by the analogue probe which is indicative of an undesirable positional relationship of the object and analogue probe.

12. A method as claimed in claim 1 , in which the difference between previous and subsequent traverses is sufficiently small such that if along the previous traverse no surface measurement data was obtained, the subsequent traverse will not cause the analogue probe to exceed its measurement range.

13. A method as claimed in claim 1 , in which it is determined whether the analogue probe obtained scanned measurement data based solely on the data from the analogue probe.

14. A method as claimed in claim 1 , comprising determining the location and/or orientation of the object based on the scanned measurement data obtained.

15. A method as claimed in claim 1 in which the analogue probe is a contact scanning probe comprising a deflectable stylus for contacting the object.

16. A method of finding at least part of an object using an analogue probe mounted on a machine tool, the method comprising causing the analogue probe and/or object to follow a course of motion which is configured such that the analogue probe is initially sufficiently far away from the object and the course of motion is configured to cause the analogue probe's surface sensing region to traverse across at least said part of the object to be found a plurality of times without being in a position sensing relationship with anything and approaching the object over successive traverses so as to ultimately arrive in a position sensing relationship with said part of the object so as to collect scanned measurement data about the said part of the object along at least part of a traverse.

17. A method of finding at least part of an object using an analogue probe mounted on a machine tool, the method comprising causing the analogue probe and/or object to follow a course of motion which is configured such that the analogue probe is initially sufficiently far away from the object and the course of motion is configured to cause the analogue probe's surface sensing region to traverse with respect to at least said part of the object to be found a plurality of times without being in a position sensing relationship with anything and approaching the object over successive traverses so as to ultimately arrive in a position sensing relationship with said part of the object so as to collect scanned measurement data about said part of the object along at least part of a traverse.

18. A method of finding at least part of an object using an analogue probe mounted on a machine tool, the method comprising causing the analogue probe and/or object to follow a course of motion which is configured such that the analogue probe is initially sufficiently far away from the object and the course of motion is configured to cause the analogue probe's surface sensing region to move laterally back and forth with respect to at least said part of the object to be found a plurality of times without being in a position sensing relationship with anything and approaching said part of the object so as to ultimately arrive in a position sensing relationship with said part of the object so as to collect scanned measurement data about said part of the object.

19. A method of finding an object using a contact analogue probe having a workpiece contacting stylus mounted on a machine tool, the method comprising causing the contact analogue probe and/or object to follow a course of motion which is configured such that the contact analogue probe's workpiece contacting stylus is initially not in contact with the object and such that the contact analogue probe's workpiece contacting stylus traverses in free space with respect to the object to be found and approaching the object over subsequent traverses so as to ultimately arrive in a position sensing relationship with the object so as to collect scanned measurement data about the object along at least part of a traverse.

Assignees

• Renishaw Plc

Inventors

• Ould John
• Tett Kevin

Classifications

• G01B7/012 Primary

  Contact-making feeler heads therefor · CPC title

• G01B21/045 Primary

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