1、AN AMERICAN NATIONAL STANDARDPerformance Evaluation of Laser-BasedSpherical Coordinate Measurement SystemsASME B89.4.19-2006Intentionally left blank ASME B89.4.19-2006Performance Evaluationof Laser-BasedSpherical CoordinateMeasurement SystemsAN AMERICAN NATIONAL STANDARDThree Park Avenue New York, N
2、Y 10016Date of Issuance: November 30, 2006The next edition of this Standard is scheduled for publication in 2011. There will be no addendaissued to this edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisStandard. Interpretations are published on
3、the ASME website under the Committee Pages athttp:/cstools.asme.org as they are issued.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under procedures accredited as meeting the criteria for American NationalStandards. The Standard
4、s Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate. The proposed code or standard was madeavailable for public review and comment that provides an opportunity for additional public input
5、from industry, academia,regulatory agencies, and the public-at-large.ASME does not “approve,” “rate,” or “endorse” any item, construction, proprietary device, or activity.ASME does not take any position with respect to the validity of any patent rights asserted in connection with anyitems mentioned
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7、sk of infringement of such rights, isentirely their own responsibility.Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted asgovernment or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretat
8、ions of this document issued in accordance with the establishedASME procedures and policies, which precludes the issuance of interpretations by individuals.No part of this document may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of th
9、e publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2006 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster vCorrespondence With the B89 Committee . vi1 Scope . 12 Introduction
10、. 13 Specifications and Rated Conditions 24 Definitions 25 Test Environment 56 Performance Tests . 57 Analysis of Performance Evaluation Tests 138 References 16Figures1 Laser Tracker and Reference Interferometer Alignment . 122 Cosine Error Versus Offset C From Reference Line . 143 Least Squares Lin
11、e Fit to 12 Short Reference Lengths . 16Tables1 Laser Tracker Performance Evaluation Requirements . 62 Horizontal Length Measurement System Test 83 Vertical Length Measurement System Test . 84 Right Diagonal Length Measurement System Test 95 Left Diagonal Length Measurement System Test . 96 Two-Face
12、 System Test Measurement . 107 Ranging Test 11Mandatory AppendixI Reference Length Traceability 19Nonmandatory AppendicesA Traceability of Subsequent Measurements 21B Spherically Mounted Retroreflector (SMR) Tests 22C Refractive Index of Air 26D Reference Lengths for Laser Tracker System Tests 29E E
13、ffect of Air Temperature on Laser Tracker Measurements 36F Laser Tracker Interim Testing 41iiiFOREWORDASME Standards Committee B89 on Dimensional Metrology, under procedures approved bythe American National Standards Institute (ANSI), prepares standards that encompass the inspec-tion and the means o
14、f measuring characteristics of such various geometric parameters as diameter,length, flatness, parallelism, concentricity, and squareness.Division B89.4 produces Standards and Technical Reports in the area of coordinate measuringtechnology, with particular focus on coordinate measuring machines (CMM
15、s). This Standard,addressing the performance evaluation of laser trackers and similar large-scale measurementsystems, is the work of the B89.4.19 Project Team on Optical CMM Evaluation.Performance evaluation of a laser tracker presents challenges different from those associatedwith conventional Cart
16、esian CMMs. Because of the very large working volume, no full-scale,three-dimensional calibrated artifacts exist, and the design of the laser beam steering system issuch that individual parametric errors cannot, in general, be isolated and measured individually.For any coordinate measurement system,
17、 a fundamental requirement is a test of its ability to realizethe SI unit of length, the meter. In a laser tracker, the length scale is often a laser interferometer andusually one does not have a significantly more accurate reference interferometer with which toperform such a test.For these reasons,
18、 the performance evaluation tests in this Standard consist primarily of point-to-point length measurements using calibrated artifacts that can be realized in a number ofways. Measured lengths are compared with manufacturers Maximum Permissible Error (MPE)specifications in order to decide conformance
19、. Realization of the SI meter can be evaluated in anumber of ways, including calibration of the laser interferometer, measurement of a series ofshort calibrated reference lengths, or measurement of a series of long calibrated reference lengths.Procedures are also included for testing the absolute di
20、stance measurement (ADM) capability oflaser trackers that include this option.All reference lengths used in the performance evaluation tests are required to be traceable perASME B89.7.5. Guidance is provided on how to demonstrate this traceability, as well as thetraceability of subsequent point-to-p
21、oint length measurements made with a laser tracker that haspassed the performance evaluation tests of this Standard.Suggestions for improvement of this Standard are welcome. They should be sent to The Ameri-can Society of Mechanical Engineers, Secretary, B89 Standards Committee, Three Park Avenue,Ne
22、w York, NY 10016-5990.This Edition was approved by the American National Standards Institute on January 30, 2006.ivASME B89 COMMITTEEDimensional Metrology(The following is the roster of the Committee at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSB. Parry, ChairD. Beutel, Vice
23、 ChairF. Constantino, SecretarySTANDARDS COMMITTEE PERSONNELD. Beutel, CaterpillarJ. B. Bryan, Bryan AssociatesT. Carpenter, U.S. Air Force Metrology LabsR. L. Thompson, Alternate, U.S. Air ForceT. Charlton, Jr., Charlton AssociatesD. Christy, Mahr Federal, Inc.F. Constantino, The American Society o
24、f Mechanical EngineersG. A. Hetland, International Institute of Geometric Dimensioningand TolerancingSUBCOMMITTEE 4: COORDINATE MEASURING TECHNOLOGYS. D. Phillips, Chair, National Institute of Standards andTechnologyB. Borchardt, National Institute of Standards and TechnologyT. E. Carpenter, U.S. Ai
25、r Force Metrology LabsT. Charlton, Jr., Charlton AssociatesK. G. Harding, General ElectricR. J. Hocken, University of North Carolina, CharlotteJ. J. Hooker, RDM, Inc.PROJECT TEAM 4.19: OPTICAL CMM EVALUATIONJ. D. Brehm, McDonnell Douglas Co.R. E. Bridges, FARO TechnologiesG. W. Caskey, University of
26、 North Carolina, CharlotteJ. D. Drescher, United Technologies Corp., Pratt however, theyshould not contain proprietary names or information.Requests that are not in this format will be rewritten in this format by the Committee priorto being answered, which may inadvertently change the intent of the
27、original request.ASME procedures provide for reconsideration of any interpretation when or if additionalinformation that might affect an interpretation is available. Further, persons aggrieved by aninterpretation may appeal to the cognizant ASME Committee or Subcommittee. ASME does not“approve,” “ce
28、rtify,” “rate,” or “endorse” any item, construction, proprietary device, or activity.Attending Committee Meetings. The B89 Standards Committee regularly holds meetings, whichare open to the public. Persons wishing to attend any meeting should contact the Secretary ofthe B89 Standards Committee.viASM
29、E B89.4.19-2006PERFORMANCE EVALUATION OF LASER-BASED SPHERICALCOORDINATE MEASUREMENT SYSTEMS1 SCOPEThis Standard prescribes methods for the performanceevaluation of laser-based spherical coordinate measure-ment systems and provides a basis for performance com-parisons among such systems. Definitions
30、,environmental requirements, and test methods areincluded with emphasis on point-to-point length mea-surements. The specified test methods are appropriatefor the performance evaluation of a majority of suchinstruments and are not intended to replace more com-plete tests that may be required for spec
31、ial applications.This Standard establishes requirements and methodsfor specifying and testing the performance of a class ofspherical coordinate measurement systems called lasertrackers.1A laser tracker is an instrument that directsthe light from a ranging device to a retroreflecting target(called a
32、retroreflector) by means of a two-axis rotarysteering mechanism while monitoring the angular posi-tion of these rotary axes, thereby forming a sphericalcoordinate metrology system. Such an instrument maymeasure a static target, track and measure a movingtarget, or measure (and perhaps track) some co
33、mbina-tion of static and moving targets.This Standard focuses specifically on the use of lasertrackers as industrial measurement tools rather thantheir use in surveying or geodesy. Specified tests aredesigned to evaluate the point-to-point length measure-ment capabilities of these instruments. Addit
34、ional testsare included that evaluate the range measurement capa-bility of laser trackers equipped with absolute distancemeters (ADMs). The tests do not evaluate workpiecethermal compensation capability and are not sensitive tospherically mounted retroreflector (SMR) imperfections.2 INTRODUCTIONIn a
35、ddition to providing for the performance evalua-tion of laser trackers, this Standard facilitates perform-ance comparisons among different instruments byunifying terminology and the treatment of environmen-tal factors. It defines test methods appropriate for evalu-ating the performance of a majority
36、 of such instruments1For purposes of this Standard, the terms spherical coordinatemeasurement system and laser tracker will be used interchangeably,notwithstanding the ability or inability to track a target.1and is not intended to replace more complete tests thatmay be required for special applicati
37、ons.Instruments that have passed the performance testsof this Standard are considered capable of producingtraceable point-to-point length measurements for thestated conditions required in this Standard. Applicationof point-to-point length measurements to a specificworkpiece or measurement task may r
38、equire additionaltesting and analysis in order to establish metrologicaltraceability. This Standard provides technical guidancethat may be useful in the calibration of laser based spher-ical coordinate systems for point-to-point length mea-surements.Several appendices describe various factors thatsh
39、ould be considered when using this Standard. Appen-dix I is mandatory, and the remaining Appendices arenonmandatory.(a) Mandatory Appendix I discusses metrologicaltraceability, with particular focus on demonstratingtraceability of reference lengths used in laser trackerperformance evaluation. Requir
40、ements for demonstra-ting metrological traceability are presented per ASMEB89.7.5 Technical Report.(b) Nonmandatory Appendix A discusses the trace-ability of laser tracker point-to-point length measure-ments performed subsequent to an instruments passingthe performance tests described in this Standa
41、rd.(c) Nonmandatory Appendix B describes tests andprocedures for determining geometric errors in the con-struction of SMRs so that the suitability of a particularSMR for laser tracker testing can be evaluated.(d) Nonmandatory Appendix C describes environ-mental factors that influence the refractive
42、index of lightin air. These factors affect the wavelength of light andshould be carefully understood before proceeding withthe tests described in this Standard.(e) Nonmandatory Appendix D describes three meth-ods that can be used to establish a calibrated referencelength for point-to-point length me
43、asurement systemtests. Uncertainties in realization of such lengths arediscussed. This Appendix also describes the measure-ment capability index and a simple 4:1 acceptance deci-sion rule used to accept or reject laser trackerperformance evaluation test results.(f) Nonmandatory Appendix E describes
44、the effectsof spatial temperature gradients on laser beam propaga-tion. Equations are derived forASME B89.4.19-2006(1) radial errors due to speed of light variations(2) angular (or transverse) errors due to beamrefractionA numerical example illustrates the use of the for-mulae.(g) Nonmandatory Appen
45、dix F describes a numberof interim tests that can be used to quickly assess lasertracker measurement performance in the intervalbetween more complete performance evaluations.This Standard prescribes performance tests that maybe used by laser tracker manufacturers to generate per-formance specificati
46、ons. These specifications are statedas the Maximum Permissible Error (MPE) allowed foreach test under specified environmental conditions.Laser trackers may be tested against the manufactur-ers specifications by using the performance testsdescribed in section 6. A typical test involves measuringa kno
47、wn reference length and comparing the observederror (laser tracker measured length minus referencelength) with the specified MPE, using a 4:1 simpleacceptance decision rule per ASME B89.7.3.1-2001. Thereference length orientations and instrument positionsin the evaluation have been chosen for their
48、sensitivityto characteristic systematic errors known to occur inlaser trackers.Additional tests are included that characterize theconsistency of the coordinates of a point when measuredin both frontsight and backsight modes. Both sets oftests have been designed to be easy to implement, fastand simpl
49、e to perform. The reference lengths used inthe testing must satisfy the traceability requirements ofMandatory Appendix I. The summary test results shallbe evaluated using the performance evaluation test pro-cedures of section 7 and reported on Form 2.While this Standard specifies the technical proceduresfor laser tracker specification and evaluation, it is theresponsibility of the manufacturer and the customer tonegotiate if a particular instrument will be evaluated,including the cost and location of the evaluation. Lasertrackers that have successfully passed the performanceevaluation,
