Hybrid Optimization of Pin Type Fixture Configuration for Free Form Workpiece

This paper presents an automatic mechanism using pin type fixture for holding a workpiece during machining process. The hybrid optimization algorithm is introduced to obtain the optimum configuration of pin type fixture. Combination between Genetic Algorithms (GAs) and Particle Swarm Optimization (PSO) algorithms is enable to determine optimum clamping respect to minimum workpiece deformation. Spherical type pin fixture with array arrangement in two opposite side comforms geometry of workpiece through with two supporting action. Deformation as efect of clamping force and friction slip are predicted by simulation of pin-workpiece clamping model and analyzed by Finite Element methods. Maximum deformation and slip condition are evaluated by building the parametric script of the model. Parameters of the model is assigned by the algorithm through iteration process. Satisfies clamping arrangement to minimize the deformation and prevent the slip is evaluated using GAs to arrange the pin configuration. PSO is further applied based on the result of GAs for obtaining global optimum of objective function. Result of the evaluation shown that the optimization using two algorithms could achieve the beter position and clamping configuration for variety of workpiece geometry modeled using CAD software