A feature-based inspection process planning system for co-ordinate measuring machine (CMM) S.G. Zhanga,*, A. Ajmalb, J. Woottona, A. Chisholma
Software Department, LK Limited, East Midlands Airport, Castle Donington, Derby DE74 2SA, UK b School of Engineering, System and Design, South Bank University, London SE1 0AA, UK
Abstract This paper outlined a feature-based inspection process planning system for co-ordinate measuring machines (CMMs). The inspection process planning system is designed to produce an inspection process planning directly from CAD model. The prototype inspection process planning system includes ®ve functional modules: the tolerance feature analysis, accessibility analysis, clustering algorithm, path generation and inspection process simulation. The tolerance feature analysis module is used to input tolerance information and establish the relationship between the tolerance information and surface feature. The accessibility analysis module evaluate all the accessible probe orientations for every surface feature. The clustering algorithm module groups the inspection probe and surface features into inspection group so that time for inspection probe exchange and calibration can be reduced to minimum. The path generation module determines the number of measurement points, their distribution and their inspection sequences. The inspection process simulation module animated display the inspection probe path and check whether a collision occurs between the part and the inspection probe. The methodology and theory for corresponding ®ve functional modules are outlined. An example demonstrate the general process for the application of the inspection process planning system. The prototype inspection process planing system shown that the proposed theory and methods can be used in industry to generate an inspection process planning for a CMM. # 2000 Elsevier Science B.V. All rights reserved. Keywords: Inspection process planning; Co-ordinate measuring machines; Accessibility analysis; Clustering algorithm; Path generation
1. Introduction Recently, researches in inspection process planning have been increased . Some prototypes inspection process planning systems have been developed. These systems include the task-decomposition inspection process planning system [2±5,11], the knowledge-based inspection process planning system [6,10] and some hybrid inspection process planning systems [7±9]. However, these systems are not satis®ed by the industry. This paper outlined a prototype inspection process planning system. The inspection process planning system can be used to generate an inspection process planning for a CMM. It can be used as an integrated system starting from solid model and ®nishing at production of inspection process planning ®le. However, it can also be used as ®ve stand alone function modules for the tolerance feature decomposition, accessibility analysis, clustering algorithm, path generation and the inspection process simulation, respectively.
The inspection process planning system can be linked to a CAD system so that an inspection process planning can be produced directly once a part design has been ®nished. It is expected that the laborious and error-prone manual programming currently used for a CMM can be replaced with the developed inspection process planning system. The lead-time for the CMM programming can be reduced signi®cantly. 2. System framework The prototype inspection process planning system includes the tolerance feature analysis, accessibility analysis, clustering algorithm, path generation and inspection process simulation as shown in Fig. 1. The tolerance feature analysis module is used to input the tolerance information and then to decompose the tolerance features into individual surface inspection features. The accessibility analysis module evaluates all the possible probe orientations for a surface feature...