APPARATUS AND METHOD FOR CONTROLLING OR PROGRAMMING A MEASUREMENT ROUTINE

• US 20110192042A1
• Filed: 04/22/2008
• Published: 08/11/2011
• Est. Priority Date: 04/23/2007
• Status: Active Grant

• Current Assignee: Renishaw PLC
• Original Assignee: Renishaw PLC
• Inventors: McMurtry, David Roberts, Wallace, David Sven
• Granted Patent: US 8,601,701 B2
• Time in Patent Office: Days
• US Class Current: 33/503
• CPC Class Codes: G01B 21/042 Calibration or calibration artifacts G01B3/30, G01B9/02072 take precedence
• CPC Class Codes: G05B 19/401 characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/36452 Touch points with handheld probe, camera detects position and orientation probe
• CPC Class Codes: G05B 2219/36479 Record position on trigger of touch probe
• CPC Class Codes: G05B 2219/37193 Multicoordinate measuring system, machine, cmm
• CPC Class Codes: G05B 2219/37444 Program cmm by using a stylus to detect points on a real workpiece

Abstract

A method and apparatus for controlling or programming a measurement path for a probe mounted on a coordinate positioning apparatus (e.g. an articulating probe head mounted on a CMM) which enables both the position of the probe tip and the orientation of the probe to be varied. In a first mode, the position of the probe tip is adjusted. In a second mode the orientation of the probe is adjusted, whilst keeping the location of the probe tip unchanged. This may be achieved either online on the coordinate positioning apparatus or offline in software.

Claims

1. A method for controlling or programming a measurement path for a probe mounted on a coordinate positioning apparatus which enables the orientation of the probe to be varied and the position of the probe tip to be varied angularly about at least one axis, the method comprising the steps of:

(a) adjusting the position of the probe tip or a representation of the probe tip;

(b) adjusting the orientation of the probe or a representation of the probe whilst keeping the location of the probe tip substantially unchanged.

2. A method according to claim 1 wherein the method is carried out on a coordinate positioning apparatus, and the method comprises the additional step of:

placing an object to be inspected on the coordinate positioning apparatus;

and wherein step (a) comprises positioning the probe tip at a desired location with respect to the object.

3. A method according to claim 1 wherein the method is carried out in software, and the position of the probe tip and orientation of the probe in steps (a) and (b) are adjusted with respect to a 3D model (e.g. CAD) of an object.

4. A method according to claim 3 wherein the method includes the step of determining the required positions of the moveable parts of the coordinate positioning apparatus to achieve said positions of the probe tip and probe orientation and determining whether a collision would occur between either the coordinate positioning apparatus or probe and the object.

5. A method according to claim 4 wherein a signal is generated if a collision would occur.

6. A method according to claim 3 wherein the method is implemented by a computer program when run on a computer.

7. A method according to claim 1 wherein the method includes the step of selecting the position of the probe tip or representation of the probe tip and the orientation of the probe or representation of the probe chosen in steps (a) and (b) as an input used to create the measurement path.

8. A method according to claim 7 wherein the selected position of the probe tip and probe angle or representation of the probe tip and probe angle comprises a ‘

measurement point’

at which a measurement will be taken or a ‘

via point’

through which the measurement path will move.

16. A method according to claim 1 wherein the position of the probe tip can be varied angularly about at least two axes.

9. (canceled)

10. Apparatus for controlling or programming a measurement path for a probe mounted on a coordinate positioning apparatus which enables the orientation of the probe to be varied and the position of the probe tip to be varied angularly about at least one axis, the apparatus comprising:

a controller for sending demand signals to the coordinate positioning apparatus;

a user interface capable of sending an output to the controller, the user interface having two or more modes;

wherein the controller adjusts the position of the probe tip in response to a first mode;

and wherein the controller adjusts the orientation of the probe in response to a second mode, such that the location of the probe tip is substantially unchanged.

11. Apparatus according to claim 10 wherein an output from the user interface to the controller is used to select the position of the probe tip and the orientation of the probe as a point on a measurement path.

12. Apparatus according to claim 10 wherein the user interface comprises a joystick.

17. An apparatus according to claim 10 wherein the position of the probe tip can be varied angularly about at least two axes.

13. A computer programme for programming a measurement path for a probe mounted on a coordinate positioning apparatus which enables the orientation of the probe to be varied and the position of the probe tip to be varied angularly about at least one axis, the computer programme comprising code adapted to perform the following steps when executed on a computer:

(a) combining a 3D model of the part and a 3D model of the coordinate positioning apparatus in the same coordinate frame;

(b) adjusting the position of the model of the coordinate positioning apparatus in response to an input in a first control mode in order to adjust the position of the probe tip within the 3D model;

(c) adjusting the position of the model of the coordinate positioning apparatus in response to an input in a second control mode, to adjust the orientation of the probe such that the location of the probe tip remains unchanged within the 3D model;

(d) selecting the probe tip position and probe orientation selected in steps (b) and (c) in response to a selection input

18. A computer programme according to claim 13 wherein the position of the probe tip can be varied angularly about at least two axes.

14. (canceled)

15. (canceled)