The application of the simulated annealing method and heuristic algorithms in the selection of fixture elements

Abstract

This paper deals with the selection of suitable fixture element combinations and fixture allocation for a workpiece to allow for the different positions of the fixturing points, which are already given based on related theories. The advanced modelling extension (AME) of AutoCAD R12 was used as the 3D graphic interface. The function suitable for the AME environment was also controlled to obtain detailed data of the workpiece. First of all, the concept of group technology (GT) was used to categorise and encode the modular fixture elements with similar functions for cutting purposes. Next, the AME was combined with API (application programming interface) and Autolisp to establish the graphic illustration system for fixture elements. Then different heuristic algorithms for fixture element selection were developed to correspond to different requirements in fixture functions. The required fixture elements were then selected with the help of the simulated annealing calculation method to derive a suitable and economical number of fixture element combinations. The height of the fixture element combination derived may not match the height of the fixture point originally located. The workpiece shape also affects the allocated position of the fixture elements. Therefore, a number of heuristic algorithms were developed in this study to process all the factors involved and to obtain a desirable selection for fixture elements.