ASME B89.4.10 pdf download MethodsforPerformance Evaluation of Coordinate Measuring System Software
A critical issue in industria. coordinate metrology is the measurement of a work iece to assure compliance with itedimensional reguirements When using a computerized coordinate measuring system (CMS), the usual practice is tocorrelate computer-calculated outputs with the dimensional requirements of the workpiece. This correlation isperformed by various computer routines that process dimensional coordinate data sets consisting of measurementsamples of the object being evaluated.
The purpose ofthis Standard is to provide guidelines for evaluating the quality of solutions generated by CMS softwareand to define minimal documentation requirements for software providers. Additionally, this Standard gives defaultdefinitions for collections of data sets that span a variety of real-world measuring scenarios. These data sets are dependent on the fiting algorithm being tested. This Standard is concerned with testing the behavior of algorithm implementation, not the testing of algorithms themselves.Thus, the sotware is treated as a black box: only the input and outputare observed and evaluated. it is not the intent of this Standard to endorse or rate any computational method or system.Software performance evaluation is useful because it
(a) allows objective validation of software(b) reduces the possibility of error in software application(c) defines a method of comparing CMS softwareThis Standard covers the following areas: input data, feature construction, software documentation, performancecharacterization, and test methodologies.
The assumptions inherent in this Standard are as follows:
(a) Measurement uncertainty in coordinate samples is not addressed.(b) Methods to input predetermined samples to the computational system are available.(C)Personnel have adequate experience and training to implement the evaluation and understand the implications ofthe results.
This Standard is one component required for the evaluation of CMSs. Other relevant documents can be found inNonmandatory Appendix E.
The following is a list of standards referenced in this Standard. Unless otherwise noted, the most recent edition shallapply.
ASME Y14.5，Dimensioning and TolerancingASME Y14.5.1, Mathematical Definition of Dimensioning and Tolerancing PrinciplesPublisher: The American Society of Mechanical Engineers (ASME), Two Park Avenue, New York,NY 10016-5990[www.asmeorg)
See Nonmandatory Appendix E for additional, informative references.
algorithm: a well-defined procedure for solving a particular problem, e.g, sorting algorithms.
coordinate measuring system (CMS): any piece of equipment that collects coordinates (points), calculates, and displaysadditional information using the measured points.
datum: a theoretically exact point, line, or plane derived from a feature on a part See ASME Y14.5M-2018east-squares fit feature: a feature of perfect form, corresponding to a set of data points, that minimizes the sum of thsquared deviations between the feature and the individual data points.(Reference Nonmandatory Appendix C for additional information.) This term is elsewhere sometimes referred to as the Gaussian associated feature.NOTE: in this Standard,unless otherwise indicated, the east-squares fit is understood to be not weighted, e. each point is given equaweight in the least-squares objective function,AA1the points in thetest data are not exactly evenly spaced.
obiective function: a function which is to be optimized by searching or a minimum or maximum) as its parameters arevaried.A different objective function is used for each type offit, e.g, aleast-squares versus minimum-circumscribed circle.reference evaluation: the evaluation of the substitute feature using a known implementation of an algorithm.reference feature: a substitute feature used as the basis for evaluating a test feature.substitute feature: a feature ofperfect geometric form that corresponds to a set of data points and is intended to minimize
an obiective function.test: a basic unit of evaluation, based on one or more related data sets, which are applied to one or more softwareimplementations of an algorithm.
test feature: a substitute feature computed by the software under test.