Modeling and Optimization of Fixture for Handling Compliant Sheet Metal Parts

Material handling of compliant parts is one of the most critical and underresearched problems in the sheet metal stamping industry. The fundamental shortcoming of currently studied material handling systems for sheet metal stamping is the lack of analysis of its impact on part dimensional quality and production throughput. This paper addresses this problem by development of a generic methodology for modeling and optimization of part holding end-effector fixture layout in order to minimize part dimensional deformation during handling operations. The methodology extends the design of “N-2-1” fixturing layout by adding part movability conditions. It considers part CAD model, handling direction and motion kinematic parameters to determine the best end effector layout. This methodology is realized by integrating FEM part and loading modeling with the optimization algorithm. It can be implemented into the design stage of a stamping line so that the trial and error process, which is current industrial practice, can be greatly shortened and the production throughput increased. Experimental results verify the proposed part holding end-effector layout methodology.