Application of ANN in the Machining Fixture Layout Optimization for Minimum Deformation of Workpiece using FEM

摘要

Machining fixtures are used to locate and constrain a workpiece during a machining operation. Fixture layout is the positioning of fixturing elements such as locators and clamps. To ensure that the workpiece is manufactured according to specified dimensions and tolerances, it must be appropriately located and clamped. Minimizing workpiece deformation due to clamping and cutting forces is essential to maintain the machining accuracy. An ideal fixture design exhibits minimal deformation while machining. The purpose of this research work is to design an optimum fixture layout in order to reduce the maximum elastic deformation of the workpiece caused by the clamping and machining forces acting on the workpiece while machining. This can be achieved by selecting the optimal location of fixturing elements such as locators and clamps. Finite element method (FEM) is used to find out the maximum deformation of the workpiece for various possible fixture layouts. Artificial neural network (ANN) is used as an optimization tool to find the optimal location of the locators and clamps. To train the ANN, sufficient sets of input and output are fed to the ANN system. The input includes the position of the locators and clamps. The output includes the maximum deformation of the workpiece for the corresponding fixture layout under machining condition. In the querying phase, the ANN results are compared with the FEM results. After the querying process, the trained ANN is used to predict the maximum deformation of the possible fixture layouts within the solution region. The layout which shows minimum deformation is selected as optimal fixture layout.