COMPUTER-AIDED INTEGRATED METHOD FOR EFFECTIVE DEVELOPMENT OF ROBOTIC WELDING PROCESSES OF CAR CHASSIS ASSEMBLY

Abstract

Car manufacturing companies continuously drive the innovation of automotive products and related manufacturing processes, mainly basing on dedicated methods for automotive chassis design and also on the related welding assembly processes. The former aim to improve the final quality of entire chassis through the optimization of rigidity/weight ratio and through the use of high performance materials. The latter aim to enhance chassis performance and reducing total production costs by reducing waste using reconfigurable welding robotic lines. Accordingly, new integrated design methodologies are required to take into account related constraints and specifications of both product/process design phases as well as it is suggested a concurrent usage of numerical methods and simulation tools to evaluate the robotic systems configuration and robot programming. This paper presents a novel design method which aims to overcome the drawbacks of the present methods by means to evaluate the assembly operations before the detail design of the chassis and the concept design of the fixture system exploiting computer-aided tools. In particular, this work focuses on the process phase of the design method which aims to integrate robot offline programming tools to predict the welding distortions due to a modification of the robotic input parameters accordingly to the requested tolerance values. The experimental results related to a reference chassis subassembly which is joined by following the welding process based on computer-aided tools prove the effectiveness of the method proposed. Keywords: CAD-based integrated method; Tolerance stack up analysis; Welding distortions prediction; Robotic welding assembly