Abstract:
Product quality greatly depends upon the fixture quality. Proper fixture design plays a critical role in attaining the required quality of the product. Among other factors, locator’s placement is one of the significant factor in fixture design. It plays a vital role in part defect or part loss. In this research, locator’s placement of 3-2-1 DOF fixture system is optimized by using genetic algorithm to reduce positional errors. Analytical method is used to calculate the displacement of work-piece placed on the locators.
A model is proposed for the system account for external forces and torques. This model is used to calculate the overall stiffness and displacement of the workpiece. Potential energy of the elastic elements, kinetic energy of inertial elements and work done by external forces are calculated. Langrangian formulation is used to calculate the rigid body displacement of the part placed on the fixture. The positional error can be reduced by placing the locators at optimized locations. The aim of this research is to optimize the placement of six locators using GA. The aim of this algorithm is to find the minimum displacement of workpiece. Initial placement of locators is randomly generated in the algorithm and displacement of workpiece is calculated for every corresponding locator placement. Locator’s placement with minimum workpiece displacement is taken as best result.
Case study is also done to check the efficiency and effectiveness of the proposed methodology. Application of proposed model is also discussed as real time problem.
