Session: 02-01-01: Product and Process Design 1

Paper Number: 172885

Dual-Level Approach for Efficient Design of Robotic Grippers Based on Surface Bending Maps and Structural Analysis 

The growing demand for composite materials in the automotive sector, driven by the need to reduce weight and increase vehicle efficiency, has highlighted the urgency of automating handling and moulding processes. In particular, the manipulation of uncured composite materials, such as Carbon Fiber Sheet Molding Compounds (CF-SMC), presents significant challenges due to their flexible, anisotropic, and highly deformable nature. These characteristics, while essential for producing lightweight and high-performance components, make the grasping and positioning tasks particularly complex, often requiring skilled operators, resulting in productivity limits, high costs, and ergonomic risks. The presented research proposes a systematic and integrated approach for the design of robotic grippers intended for the automatic handling of these materials, with a dual purpose: on one hand, to reduce the deformations experienced by composite laminates during the grasping phase and the transfer to the mould; on the other hand, to minimize the number of required gripping modules, thereby optimizing the weight and structural complexity of the robotic grippers. The scientific contribution lies in the introduction of an integrated methodology based on a two-level analysis: an initial, simplified, and low computational cost phase based on surface bending maps derived from FEA simulations of flat plates, and a subsequent detailed validation phase through finite element models applied to the actual geometry of the component. This double analysis allows for a significant reduction in design times while maintaining the high quality and reliability of the obtained solutions.

The proposed methodology is divided into five main phases: (i) simplification of the actual geometry of the component through an equivalent planar representation; (ii) generation of a reference grid for identifying possible positions of the gripping modules; (iii) preliminary definition of the gripping pattern by overlapping elementary areas of bending, extracted from deformation maps; (iv) validation of the chosen pattern through FEA simulations on the entire geometry; (v) design of the support structure (frame) for the grippers, optimized through further structural analyses to ensure lightness and stiffness.

A platform that combines CAD and CAE tools has been adopted to integrate all phases, from geometric modeling to structural analysis. The effectiveness of the methodology has been validated on a representative case study of a CF-SMC automotive rear hood. The results show that the first phase of analysis identifies a minimum number of 16 modules and the preliminary gripping pattern. The second phase defines the optimized pattern, keeping the maximum deformation at 8.47 mm, well below the critical limit of 18 mm required for proper positioning in the mould. Compared to the previously used heuristic approach, the new methodology has reduced deformations by 47% and the overall computation time by approximately 14%.

In conclusion, the work represents a tangible advancement in the design of gripping systems for preformed composite materials, proposing a balance between analytical accuracy and development speed. Bending maps prove to be effective tools for anticipating deformations without having to rely on complex simulations from the outset. The suggested approach can be extended to more complex geometries and, with future developments, integrated into automatic optimization tools for further reduction of design complexity. This helps to make the automation of composite handling processes economically sustainable and technically efficient, even in high-volume production contexts.

Presenting Author: Fabio Pini "Enzo Ferrari" Department of Engineering - University of Modena and Reggio Emilia

Presenting Author Biography: Associate Professor at the “Enzo Ferrari” Department of Engineering - Università degli Studi di Modena e Reggio Emilia (University of Modena and Reggio Emilia - UNIMORE), in the Academic Discipline IIND-03/B “Design Methods for Industrial Engineering”. Research scientist at the IDEALab on Computer Aided Design for Product Lifecycle Management -integrated development of industrial products and processes, design by simulation of mechanical systems, knowledge-based engineering - and on the Desing of Collaborative and Industrial robotics solutions and devices: design by simulation of robotic equipment for manufacturing and assembly operations. Teacher for the Inter-University International Degree Course in Advanced Automotive Engineering, for the Inter-University Bachelor Degree Course in Human Centered Medical System Engineering, as well as for the Bachelor Degree courses in Vehicle Engineering, and Computer Engineering of UNIMORE.

Authors:

Fabio Pini "Enzo Ferrari" Department of Engineering - University of Modena and Reggio Emilia
Alessandro Dimauro "Enzo Ferrari" Department of Engineering - University of Modena and Reggio Emilia
Francesco Leali "Enzo Ferrari" Department of Engineering - University of Modena and Reggio Emilia