Title of Invention	"A METHOD OF MEASURING AN OBJECT WITH A COORDINATE POSITIONING APPARATUS"
Abstract	• ABSTRACT ^^ A METHOD OF MEASURING AN OBJECT WITH A COORDINATE POSITIONING APPARATUS *' A method of measuring an object with a coordinate positioning apparatus, comprises the following steps: placing the object within the working volume of the coordinate positioning apparatus; measuring the object with a workpiece contacting probe to create measurement data of the object, the measurement data being collected at multiple probe forces; for at least one location on the surface of the object, determining a function or look up table relating the measurement error data to the probe force; for said at least one location on the surface of the object, using the function or look up table to determine the measurement data corresponding to zero probe force; and outputting the measurement data corresponding to zero probe force as the measurement of the object. Fig. 20 ' •

Title of Invention

"A METHOD OF MEASURING AN OBJECT WITH A COORDINATE POSITIONING APPARATUS"

Abstract

• ABSTRACT ^^ A METHOD OF MEASURING AN OBJECT WITH A COORDINATE POSITIONING APPARATUS *' A method of measuring an object with a coordinate positioning apparatus, comprises the following steps: placing the object within the working volume of the coordinate positioning apparatus; measuring the object with a workpiece contacting probe to create measurement data of the object, the measurement data being collected at multiple probe forces; for at least one location on the surface of the object, determining a function or look up table relating the measurement error data to the probe force; for said at least one location on the surface of the object, using the function or look up table to determine the measurement data corresponding to zero probe force; and outputting the measurement data corresponding to zero probe force as the measurement of the object. Fig. 20 ' •

Full Text	ORIGiNAL The present invention relates to a method of measuring an object with a coordinate positioning apparatus. The present invention relates to a method of calibrating a scanning system. A scanning system in 5 this specification should be understood to mean a combination of a machine and a probe which together are capable of use in scanning an object in order to obtain :' information about its size, shape or surface contours. 2 0 The machine may be, for example, a co-ordinate •\_ ^' ' 'measuring machine (CMM) , machine tool or robot etc, and the probe is a measuring probe with a workpiececontacting stylus. One type of machine has measuring devices for measuring the movement of the machine parts 15 in three nominally orthogonal directions (referred to • as X,Y and Z axes), and one type of probe includes measuring transducers for producing outputs indicative of the displacement of the tip of the stylus relative to the probe in three nominally orthogonal directions / 20 (referred to as the a,b, and c axes). Although the term 'analogue probe' is used, the outputs for the a,b -^\ and c axes may be either analogue or digital. In known systems, measurement errors are caused by 15 unwanted deflections of the probe, machine structure and workpiece. Errors due to bending of the probe stylus are the same throughout the machine volume and may be compensated for by probe calibration. Errors due to deflections in the machine structure may,be 30 caused, for example, by the machine quill bending and the machine bridge twisting and vary .throughout t:he machine volume. . These errors increase, for example, with increasing cantilevers. .Errors in the object to be-measured"may be caused by-object deflection during ORIGINAL We Claim; 1. A method of measuring an object (80) with a coordinate positioning apparatus, comprising the following steps, in any suitable order: placing the object within the working volume of the coordinate positioning apparatus; measuring (84, 86, 88, 90) the object (80) with a workpiece contacting I probe (82), which comprises scanning (84) the object with the workpiece i ; contacting probe, to create measurement data of the object, the measurement data being collected at multiple probe forces or probe deflections; for at least one location on the surface of the object, determining a function or look up table relating the measurement error data to the probe force or probe deflection; for said at least one location on the surface of the object, using the function or look up table to determine subsequent measurement data corresponding to zero probe force or probe deflection; and outputting subsequent measurement data corresponding to zero probe force or probe deflection as the measurement of the object. 2. A method as claimed in claim 1 wherein the measurement data corresponding to zero measurement force is determined by extrapolation. 3. A method as claimed in any of claims 1 or 2 wherein the measurement data is collected at known constant probe forces or probe deflections. 4. A method as claimed in any of claims 1 or 2 wherein the measurement data is collected at known varying probe force or probe deflection. -22- 5. A method as claimed in any preceding claim wherein the function is a linear function. 6. A method as claimed in any of claims 1-4 wherein the function is a parametric function. 7. A method as claimed in any preceding claim, wherein: the object (80) is measured along a scan path (84) and measurement data is collected at multiple probe forces or probe deflections for a section (86, 88, 90) of the scan path; the function or look up table relating the measurement data to the probe force or probe deflection is determined for locations on said section of the scan path; and wherein for locations on the scan path but not on said section of the I scan path, the function or look up table relating the measurement data to the probe force or probe deflection is determined from measurement data collected on said section of the scan path. 8. A method as claimed in claim 7 wherein the function or look up table relating the measurement data to the probe force or probe deflection for locations on the scan path (84) but not on said section (86, 88, 90) of the scan path is determined from component parts of the function or look up table relating the measurement data to the probe force or probe deflection on said section of the scan path. 9. A method as claimed in any of claims 7 or 8 wherein the object (80) may be measured along the scan path (84) by scanning a surface profile for one revolution at a constant or variable probe deflection or probe force. -23- 10. A method as claimed in any of claims 7-9 wherein measurement data is collected at multiple probe forces or probe deflections for a section (86, 88, 90) of the scan path by taking additional measurements on the scan path at a different probe force or probe deflection. 11. A method as claimed in claim 10 wherein the additional measurements are taken by scanning the surface profile for at least a quarter revolution. 12. A method as claimed in claim 10 wherein the measurements are taken by taking measurements of the surface profile as the probe is moved radially towards or away from the surface at at least two different locations (88, 90). Dated this 06* day of June, 2006. \ v^ PNA, \ [VINEET ROlfllXA] OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANTS -24-

Full Text

ORIGiNAL
The present invention relates to a method of measuring an object with a coordinate
positioning apparatus.
The present invention relates to a method of
calibrating a scanning system. A scanning system in
5 this specification should be understood to mean a
combination of a machine and a probe which together are
capable of use in scanning an object in order to obtain
:' information about its size, shape or surface contours.
2 0 The machine may be, for example, a co-ordinate
•\_ ^' ' 'measuring machine (CMM) , machine tool or robot etc, and
the probe is a measuring probe with a workpiececontacting
stylus. One type of machine has measuring
devices for measuring the movement of the machine parts
15 in three nominally orthogonal directions (referred to
• as X,Y and Z axes), and one type of probe includes
measuring transducers for producing outputs indicative
of the displacement of the tip of the stylus relative
to the probe in three nominally orthogonal directions
/ 20 (referred to as the a,b, and c axes). Although the
term 'analogue probe' is used, the outputs for the a,b
-^\ and c axes may be either analogue or digital.
In known systems, measurement errors are caused by
15 unwanted deflections of the probe, machine structure
and workpiece. Errors due to bending of the probe
stylus are the same throughout the machine volume and
may be compensated for by probe calibration. Errors
due to deflections in the machine structure may,be
30 caused, for example, by the machine quill bending and
the machine bridge twisting and vary .throughout t:he
machine volume. . These errors increase, for example,
with increasing cantilevers. .Errors in the object to
be-measured"may be caused by-object deflection during

ORIGINAL
We Claim;
1. A method of measuring an object (80) with a coordinate positioning apparatus,
comprising the following steps, in any suitable order:
placing the object within the working volume of the coordinate
positioning apparatus;
measuring (84, 86, 88, 90) the object (80) with a workpiece contacting
I probe (82), which comprises scanning (84) the object with the workpiece
i ;
contacting probe, to create measurement data of the object, the measurement
data being collected at multiple probe forces or probe deflections;
for at least one location on the surface of the object, determining a function or
look up table relating the measurement error data to the probe force or probe
deflection;
for said at least one location on the surface of the object, using the
function or look up table to determine subsequent measurement data
corresponding to zero probe force or probe deflection;
and outputting subsequent measurement data corresponding to zero
probe force or probe deflection as the measurement of the object.
2. A method as claimed in claim 1 wherein the measurement data corresponding
to zero measurement force is determined by extrapolation.
3. A method as claimed in any of claims 1 or 2 wherein the measurement data is
collected at known constant probe forces or probe deflections.
4. A method as claimed in any of claims 1 or 2 wherein the measurement data is
collected at known varying probe force or probe deflection.
-22-
5. A method as claimed in any preceding claim wherein the function is a linear
function.
6. A method as claimed in any of claims 1-4 wherein the function is a parametric
function.
7. A method as claimed in any preceding claim, wherein:
the object (80) is measured along a scan path (84) and measurement
data is collected at multiple probe forces or probe deflections for a section
(86, 88, 90) of the scan path;
the function or look up table relating the measurement data to the probe
force or probe deflection is determined for locations on said section of the scan
path;
and wherein for locations on the scan path but not on said section of the
I scan path, the function or look up table relating the measurement data to the
probe force or probe deflection is determined from measurement data collected
on said section of the scan path.
8. A method as claimed in claim 7 wherein the function or look up table relating
the measurement data to the probe force or probe deflection for locations on the
scan path (84) but not on said section (86, 88, 90) of the scan path is determined
from component parts of the function or look up table relating the measurement
data to the probe force or probe deflection on said section of the scan path.
9. A method as claimed in any of claims 7 or 8 wherein the object (80) may be
measured along the scan path (84) by scanning a surface profile for one revolution
at a constant or variable probe deflection or probe force.
-23-
10. A method as claimed in any of claims 7-9 wherein measurement data is
collected at multiple probe forces or probe deflections for a section (86, 88, 90) of
the scan path by taking additional measurements on the scan path at a different
probe force or probe deflection.
11. A method as claimed in claim 10 wherein the additional measurements are
taken by scanning the surface profile for at least a quarter revolution.
12. A method as claimed in claim 10 wherein the measurements are taken by
taking measurements of the surface profile as the probe is moved radially towards
or away from the surface at at least two different locations (88, 90).
Dated this 06* day of June, 2006. \ v^ PNA, \ [VINEET ROlfllXA]
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANTS
-24-

Documents:

3234-delnp-2006-Abstract-(13-08-2013).pdf

3234-delnp-2006-abstract.pdf

3234-delnp-2006-claims.pdf

3234-delnp-2006-Correspondence Others-(07-08-2013).pdf

3234-delnp-2006-correspondence-others 1.pdf

3234-delnp-2006-Correspondence-Others-(13-08-2013).pdf

3234-DELNP-2006-Correspondence-Others-(25-10-2010).pdf

3234-delnp-2006-correspondence-others.pdf

3234-delnp-2006-description (complete).pdf

3234-delnp-2006-Drawings-(13-08-2013).pdf

3234-delnp-2006-drawings.pdf

3234-delnp-2006-form-1.pdf

3234-delnp-2006-form-18.pdf

3234-delnp-2006-Form-2-(13-08-2013).pdf

3234-delnp-2006-form-2.pdf

3234-DELNP-2006-Form-3-(25-10-2010).pdf

3234-delnp-2006-form-3.pdf

3234-delnp-2006-form-5.pdf

3234-delnp-2006-GPA-(13-08-2013).pdf

3234-delnp-2006-gpa.pdf

3234-delnp-2006-pct-101.pdf

3234-delnp-2006-pct-210.pdf

3234-delnp-2006-pct-220.pdf

3234-delnp-2006-pct-237.pdf

3234-delnp-2006-pct-304.pdf

3234-delnp-2006-pct-308.pdf

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Patent Number

259796

Indian Patent Application Number

3234/DELNP/2006

PG Journal Number

13/2014

Publication Date

28-Mar-2014

Grant Date

27-Mar-2014

Date of Filing

06-Jun-2006

Name of Patentee

RENISHAW PLC.,

Applicant Address

NEW MILLS, WOTTON-UNDER -EDGE, GLOUCESTERSHIRE GL12 8JR, ENGLAND

Inventors:

#	Inventor's Name	Inventor's Address
1	GEOFFREY MCFARLAND	THE MANSE, 22 CHURCH ROAD, UPPER CAM, DURSLEY GLOUCESTERSHIRE GL11 5PG , GREAT BRITAIN
2	DAVID ROBERTS MCMURTRY	PARK FARM, STANCOMBE, DURSLEY, GLOUCESTERSHIRE GL11 6AT, GREAT BRITAIN
3	KEVYN BARRY JONAS	15C BEAUFORT ROAD, CLIFTON, BRISTOL BRISTOL BS8 2JU, GREAT BRITAIN

PCT International Classification Number

G01B 21/04

PCT International Application Number

PCT/GB2004/005276

PCT International Filing date

2004-12-16

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0329098.8	2003-12-16	U.K.