Evaluation Of Deviations Due To Robot Configuration For Robot-based Incremental Sheet Metal Forming

Abstract

Industrial robot-based Incremental Sheet metal Forming (ISF) is known as Roboforming. Industrial robots are being adopted for forming operations because they allow higher tool flexibility in terms of positioning and orientating the tool and a larger workspace at a minimum cost compared to CNC-based ISF. However, the lower stiffness of the robots leads to undesirable geometrical anomalies and deviations in the formed part. Along with the externally applied forces, robot configuration changes also impact the tool’s positional accuracy. An attempt has been made to study the influence of robot configurations on overall part deviations in Roboforming due to robot compliance. Understanding changes in compliance or stiffness changes owing to different robot poses is a necessary step for optimizing the transition from a traditional CNC-based ISF to a robot-assisted ISF. Robot stiffness-based deviations are evaluated using an analytical approach, and configuration-based deflections are studied using FEM-based approaches for their contribution to the overall part deviations. Results are compared to the sheet metal forming experiments conducted over conventional 3-axis CNC for forming a cone-shaped profile using a spiral toolpath. It is highlighted that the overall deviations in the formed components are influenced by robot compliance and pose.