Elsevier

Measurement

Volume 92, October 2016, Pages 326-339
Measurement

Towards an intelligent approach for CMM inspection planning of prismatic parts

https://doi.org/10.1016/j.measurement.2016.06.037Get rights and content

Highlights

  • An intelligent approach for CMM inspection planning of prismatic parts.

  • Inspection feature construction.

  • Probe accessibility analysis.

  • Automated collision-free generation.

  • Probe path planning.

Abstract

This paper presents a model of prismatic parts (PPs) inspection planning on CMMs, in terms of an intelligent concept of inspection planning. The developed model is composed of Inspection Feature Construction, Sampling Strategy, Probe Accessibility Analysis, Automated Collision-Free Generation, and Probe Path Planning. In this model, the simulation of a measuring probe path is based on three algorithms: Algorithm for Measurement Points Distribution, Algorithm for Collision Avoidance, and Algorithm for Probe Path Planning. The simulation output is a measuring protocol for CMM UMM500. An experiment was performed on two PPs that have been produced for the purpose of this research. The inspection results show that all tolerances for both PPs are within the specified limits. The proposed model presents a novel approach for the automatic inspection and a basis for the development of an integrated, intelligent concept of inspection planning. The advantages of this approach imply the reduction of preparation time due to an automatic generation of a measuring protocol, a possibility for the optimisation of measuring probe path, i.e. the reduction of a time needed for the actual measurement and analysis of a workpiece, and an automatic configuration of measuring probes.

Introduction

Research and development of intelligent systems for inspection planning on coordinate measuring machines (CMMs) present a precondition for the development of a new generation of metrological systems and their application in a digital quality concept, which is based on a global product interoperability model [1], [2], [3], [4], [5] where CAD-CAM-CAI information are integrated within a digital platform [6], [7]. This approach presents a basis for virtualization, simulation and planning of inspection based on knowledge, particularly for the inspection of prismatic parts (PPs) on CMM. From the other side, digital manufacturing presents a framework for the development of a new generation of technological systems based on virtualization, digital model of a product and application of cloud computing concept [3], [5].

Prismatic parts (PPs) are an important group of mechanical parts frequently used in industry. PPs are consisted from the basic geometric features such as plane, cylinder and cone. From the metrological aspect, this group also implies free from surfaces whose inspection is not strictly required, and they are present mainly due to esthetical or some related reasons. PPs are present in almost all types of manufacturing. In this paper, our focus is on parts with medium and high quality of tolerances precision used to build machine tools.

Literature review shows that the development of inspection planning on CMMs in the last three decades has passed through the following phases: manual planning, planning generated by CAI software (which is still the most commonly used approach), planning obtained by an expert system [8], and an intelligent concept of inspection planning [9], [10], [11], [12], [13], [14]. The common element of all these approaches is a workpiece, i.e. the touching object used for measurements. According to the manner of an analysis and synthesis of workpiece geometric information (tolerances), three approaches could be distinguished: (i) analysis of geometry [15], [16], [17], (ii) analysis of tolerances [18], [19], [20], [21], [22], [23], and (iii) combined approach [24], [25], [26].

It is well known that the inspection process is composed of few key elements such as path planning, collision avoidance, accessibility analysis and a workpiece setup, as well as configuration of measuring probes. A complete system for inspection planning contains all mentioned key elements. Hwang’s approach for the inspection planning [27] involves some of these elements, such as a workpiece setup and configuration of measuring probes. A purpose of Weckenmann’s analyses the practicability of extensive analytical comparison tests of different 1D, 2D and 3D artefacts [28] is the determination of meaningful positioning of the artefact in the measuring volume of the machine. Several related researches show the approaches for path planning [29], [30], [31], [32], [33], collision avoidance [34], [35], accessibility analysis [36], [37], [38], [39], [40], [41], [42], [43], and configuration of measuring probes [44], [45], [46], [47], [48], [49]. The inspection planning could be also analysed through the local and global inspection planning [50]. Systems for inspection planning could be feature-based [51], [52], [53], [54], [55], [56] and knowledge based [57]. Wong’s approach [58] presents the off-line measurement planning system composed of three modules: module for input data, module for measurement planning, and module for statistical analysis. An example of the extraction of geometric information from CAD model and formation of input data is presented in [59]. An automatic inspection planning on CMMs based on B-representation of solid model in SAT format is given in [60], and at the end CMM program is generated in DMIS format.

One of the first steps in the development of an intelligent inspection concept is the integration of geometry and tolerances of prismatic parts (PPs) that participate in planning of PPs inspection. In order to accomplish this, the knowledge base was developed [69] to shows geometric feature that participates in the tolerance creation. Novelty in this paper refers to the development of collision-free measuring path based on the geometry and tolerances defined in knowledge base. The geometry of a part is presented by a set of points or point-to-point measuring path, where the path corresponds to inspection of the given PP tolerances.

The main difference between the model proposed in this paper and the approaches from the literature is in the definition of the workpiece, i.e. an object of a measurement. In coordinate metrology, the definition of the workpiece from the geometric aspect and the aspect of tolerances should be considered together. In the analysis of PPs, from the geometrical aspect the workpiece is characterised by geometric features (e.g. plane, cylinder), but from the aspect of tolerances the workpiece is characterised by metrological features (e.g. distance between two planes or two cylinders). The link between these two types of features (geometric and metrological) implies the type of tolerance. Based on this, the measuring probe path could be considered as a set of points composed of three sub-sets: (i) the first sub-set contains measuring points that can be obtained based on geometric information; (ii) the second sub-set contains the remaining points that measuring probe uses for the inspection of one geometric feature, that could be also obtained from geometric information; (iii) the third sub-set enables to avoid a collision, and this set must be defined based on tolerance information (i.e. link between two geometric features).

The proposed research is consisted of a Model for off-line Inspection Planning (MIP) of PPs on CMM and simulation of measuring probe paths based on this model. The main idea is to generate the measuring probe path based on CAD model of PP and its tolerances.

Section snippets

The proposed model for inspection planning of PPs on CMM

The elements of an off-line inspection planning of PPs are coordinate measuring systems (of measuring machine, measuring probe and workpiece), configuration of measuring probes, principle of collision avoidance, module for metrological recognition of PPs, local inspection plan and global inspection plan. The configuration of measuring probes is a result of Probe Accessibility Analysis (PAA). The module for metrological recognition is based on CAD model of PPs in an external record (IGES file)

Simulation of a measuring probe path

An example of the simulation of PP inspection on CMM is presented in this section. It is based on the pre-defined model, and it gives a measuring protocol and list of related data as the output. The simulation is based on three algorithms.

Experiment and results

Experiment involves measurement of two PPs according [65], [66], [67]. Both of the workpieces are produced for this research. Testing of the presented model is initially performed using the simpler workpiece, i.e. prismatic part 1 (PP1). This workpiece is composed of all geometric features embraced by the MIP model. After the successfully performed experiment on PP1, testing of the model is performed on the second, more complex workpiece – prismatic part 2 (PP2).

In comparison to PP1, PP2

Conclusion

An intelligent approach for inspection planning on CMM integrates PPs metrological and tolerance complexity with the knowledge of an inspection planner, and as the output it gives a measuring protocol or the list of data for CMM control.

The research depicts in this paper presents a basis for its future development. This is reflected in the following benefits: reduction of a preparation time based on the automatic generation of a measuring protocol, the possibility for the optimisation of a

Acknowledgments

The presented research was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia and Vienna University of Technology, Department for Interchangeable Manufacturing and Industrial Metrology, Institute for Production Engineering and Laser Technology, High Precision Measurement Room – Nanometrology Laboratory.

References (79)

  • A. Wozniak et al.

    Metrological feasibilities of CMM touch trigger probes. Part I: 3D theoretical model of probe pretravel

    Measurement

    (2003)
  • J. Jackman et al.

    Probe orientation for coordinate measuring machine systems using design models

    Robotics Comput.-Integr. Manuf.

    (1998)
  • G. Moroni et al.

    Knowledge based method for touch probe configuration in an automated inspection system

    J. Mater. Process. Technol.

    (1998)
  • F. Zhao et al.

    Computer – aided inspection planning – the state of the art

    Comput. Ind.

    (2009)
  • T.R. Kramer et al.

    A feature – based inspection and machining system

    Comput. Aided Des.

    (2001)
  • K. Takamasu et al.

    Basic concept of feature-based metrology

    Measurement

    (1999)
  • S. Kim et al.

    The development of the off-line measurement planning system for inspection automation

    Comput. Ind. Eng.

    (1996)
  • G. Lee et al.

    Sampling strategy design for dimensional measurement of geometric features using coordinate measuring machine

    Int. J. Mach. Tools Manuf.

    (1997)
  • V. Majstorovic et al.

    CAI model for prismatic parts in digital manufacturing

    Proc. CIRP

    (2014)
  • A. Weckenmann et al.

    The influence of measurement strategy on the uncertainty of CMM-measurements

    Ann. ClRP

    (1998)
  • Weckenmann et al.

    Functionality-oriented evaluation and sampling strategy in coordinate metrology

    Precis. Eng.

    (1995)
  • G.T. Anthony et al.

    Reference software for finding Chebyshev best-fit geometric elements

    Precis. Eng.

    (1996)
  • A. Weckenmann et al.

    Design of gauges and multipoint measuring systems using coordinate-measuring-machine data and computer simulation

    Precis. Eng.

    (1991)
  • P. Bourdet et al.

    Effects of data point distribution and mathematical model on finding the best-fit sphere to data

    Precis. Eng.

    (1993)
  • T. Killmaier et al.

    Genetic approach for automatic detection of form deviations of geometrical features for effective measurement strategy

    Precis. Eng.

    (2003)
  • J. Sładek et al.

    Evaluation of coordinate measurement uncertainty with use of virtual machine model based on Monte Carlo method

    Measurement

    (2012)
  • Y.F. Zhao et al.

    Information Modeling for Interoperable Dimensional Metrology

    (2011)
  • E. Westkamper

    Digital manufacturing in the global era

  • E. Westkamper

    Factories of the future beyond 2013 – a view from research: the role of ICT

  • <http://www.steptools.com/library/stepnc/> (accessed December...
  • R. Laguionie et al.

    An extended manufacturing integrated system for feature – based manufacturing with STEP-NC

    Int. J. Comput. Integr. Manuf.

    (2011)
  • ...
  • A.H. ElMaraghy et al.

    Expert system for inspection planning

    Ann. CIRP

    (1987)
  • G.C. Lu et al.

    Genetic algorithm modelling and solution of inspection path planning on a coordinate measuring machine (CMM)

    Int. J. Adv. Manuf. Technol.

    (1999)
  • S. Stojadinovic et al.

    Towards the development of feature – based ontology for inspection planning system on CMM

    J. Mach. Eng.

    (2012)
  • Q. Liangsheng et al.

    Optimization of the measuring path on a coordinate measuring machine using genetic algorithms

    Measurement

    (1998)
  • X.G. Zhang et al.

    Towards the intelligent CMM

    Ann. CIRP

    (2002)
  • H.P. Osanna

    Intelligent production metrology – a powerful tool for intelligent manufacturing

    e&i Elektrotechnik und Informationstechnik

    (1997)
  • P.D. Stefano et al.

    An approach for feature semantics recognition in geometric models

    Comput. Aided Des.

    (2004)
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