Calibration of measurement probes

Patent metadata

Field	Value
Publication number	US-10401162-B2
Application number	US-201515305441-A
Country	US
Kind code	B2
Filing date	Apr 23, 2015
Priority date	Apr 23, 2014
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A machine tool is provided with a toolsetting probe mounted on a bed or table, and a workpiece-sensing probe which can be mounted in a movable spindle. Both probes are calibrated by using them to make measurements against each other. The arbitrary length of the workpiece-sensing probe is used to calibrate the toolsetting probe, rather than using a pre-calibrated artefact of known length mounted in the spindle. A stylus disc of the toolsetting probe has a pre-calibrated size or dimension, and the workpiece-sensing probe is calibrated with respect to that. This obviates the need for skilful manual calibration procedures using pre-calibrated artefacts and manual measurement tools.

First claim

The invention claimed is:

1. A method of calibrating or datuming probes on a machine tool, the machine tool comprising:
a first part on which a workpiece is mountable;
a second part on which a tool is mountable, the first and second parts being movable relative to each other;
a control which controls the relative movement of the first and second parts of the machine tool;
a toolsetting probe mountable on the first part; and
a workpiece-sensing probe mountable on the second part;
the method comprising:
moving the first and second parts of the machine tool relative to each other to bring the toolsetting and workpiece-sensing probes into a sensing relationship with each other in a probing direction, a dimension or position of a first one of the probes being used to set one or more parameters of a second one of the probes in the probing direction; and
storing the one or more parameters of the second probe in the control,

wherein:
a dimension of the toolsetting probe is used to set one or more parameters of the workpiece-sensing probe,
the probing direction is an X-axis and/or Y-axis direction of the workpiece-sensing probe, and
the one or more parameters of the workpiece-sensing probe include an effective radius or diameter of a stylus tip of the workpiece-sensing probe.

2. A non-transitory computer-readable medium storing a software program for a control of a machine tool, the software program being configured to cause the control of the machine tool to perform the method according to claim 1 .

3. A control for a machine tool, comprising a memory storing a software program configured to cause the control to perform the method according to claim 1 .

4. A machine tool having the control according to claim 3 .

5. The method according to claim 1 , wherein a size of the dimension of the toolsetting probe is pre-calibrated.

6. The method according to claim 1 , wherein the dimension of the toolsetting probe is on a deflectable stylus of the toolsetting probe.

7. A method of calibrating or datuming probes on a machine tool, the machine tool comprising:
a first part on which a workpiece is mountable;
a second part on which a tool is mountable, the first and second parts being movable relative to each other;
a control which controls the relative movement of the first and second parts of the machine tool;
a toolsetting probe mountable on the first part; and
a workpiece-sensing probe mountable on the second part;
the method comprising:
moving the first and second parts of the machine tool relative to each other to bring the toolsetting and workpiece-sensing probes into a sensing relationship with each other in a probing direction, a dimension or position of a first one of the probes being used to set one or more parameters of a second one of the probes in the probing direction; and
storing the one or more parameters of the second probe in the control,

wherein:
a dimension of the toolsetting probe is used to set one or more parameters of the workpiece-sensing probe, and
a trigger signal from the workpiece-sensing probe is used to set the one or more parameters of the workpiece-sensing probe from the dimension of the toolsetting probe.

8. The method according to claim 7 , wherein a size of the dimension of the toolsetting probe is pre-calibrated.

9. The method according to claim 7 , wherein the dimension of the toolsetting probe is on a deflectable stylus of the toolsetting probe.

10. A method of calibrating or datuming probes on a machine tool, the machine tool comprising:
a first part on which a workpiece is mountable;
a second part on which a tool is mountable, the first and second parts being movable relative to each other;
a control which controls the relative movement of the first and second parts of the machine tool;
a toolsetting probe mountable on the first part; and
a workpiece-sensing probe mountable on the second part;
the method comprising:
moving the first and second parts of the machine tool relative to each other to bring the toolsetting and workpiece-sensing probes into a sensing relationship with each other in a probing direction, a dimension or position of a first one of the probes being used to set one or more parameters of a second one of the probes in the probing direction; and
storing the one or more parameters of the second probe in the control,

wherein:
a dimension of the toolsetting probe is used to set one or more parameters of the workpiece-sensing probe, and
a trigger signal from the toolsetting probe is used to set the one or more parameters of the workpiece-sensing probe from the dimension of the toolsetting probe.

11. The method according to claim 10 , wherein a size of the dimension of the toolsetting probe is pre-calibrated.

12. The method according to claim 10 , wherein the dimension of the toolsetting probe is on a deflectable stylus of the toolsetting probe.

13. A method of calibrating or datuming probes on a machine tool, the machine tool comprising:
a first part on which a workpiece is mountable;
a second part on which a tool is mountable, the first and second parts being movable relative to each other;
a control which controls the relative movement of the first and second parts of the machine tool;
a toolsetting probe mountable on the first part; and
a workpiece-sensing probe mountable on the second part;
the method comprising:
moving the first and second parts of the machine tool relative to each other to bring the toolsetting and workpiece-sensing probes into a sensing relationship with each other in a probing direction, a dimension or position of a first one of the probes being used to set one or more parameters of a second one of the probes in the probing direction; and
storing the one or more parameters of the second probe in the control,

wherein:
a dimension of the workpiece-sensing probe is used to set a datum position or offset parameter of the toolsetting probe, and
a trigger signal from the toolsetting probe is used to set the datum position or offset parameter of the toolsetting probe from the dimension of the workpiece-sensing probe.

14. The method according to claim 13 , wherein a length dimension of the workpiece-sensing probe is measured and used to pre-position the toolsetting and workpiece-sensing probes relative to each other before they are moved into the sensing relationship.

15. The method according to claim 13 , wherein the probing direction is a Z-axis direction of the workpiece-sensing probe.

16. A method of calibrating or datuming probes on a machine tool, the machine tool comprising:
a first part on which a workpiece is mountable;
a second part on which a tool is mountable, the first and second parts being movable relative to each other;
a control which controls the relative movement of the first and second parts of the machine tool;
a toolsetting probe mountable on the first part; and
a workpiece-sensing probe mountable on the second part;
the method comprising:
moving the first and second parts of the machine tool relative to each other to bring the toolsetting and workpiece-sensing probes into a sensing relationship with each other in a probing direction, a dimension or position of a first one of the probes being used to set one or more parameters of a second one of the probes in the probing direction; and
storing the one or more parameters of the second probe in the control,

wherein:
a dimension of the workpiece-sensing probe is used to set a datum position or offset parameter of the toolsetting probe, and
a trigger signal from th

Assignees

• Renishaw Plc

Inventors

• Lummes Stephen Edward
• Cole Mark

Classifications

• G01B21/042 Primary

  Calibration or calibration artifacts (G01B3/30, G01B9/02072 take precedence) · CPC title

• G01B5/012

  Contact-making feeler heads therefor · CPC title

• G05B2219/37008

  Calibration of measuring system, probe, sensor · CPC title

• G05B19/401

  characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes (G05B19/19 takes precedence) · CPC title