FlexLean - Flexible Automation for Automotive Body Assembly

The automotive industry has pioneered the large scale use of robots. Long production runs of identical car bodies were the ideal field of application for early industrial robots, and spot welding lines with hundreds of robots have become a familiar sight. However, a lot of the production equipment is still based on hard automation. Today’s market is increasingly putting automobile manufacturers under pressure to offer customers more choice of products and variants with decreasing life cycle, while at the same time demanding lower production costs. To fulfill these apparently contradictory requirements, a single line must be able to produce a mix of different models, and must “learn” to make new models without calling for a total re-design of its equipment – and preferably without even stopping production (“rolling launches”). To responded to these demands it is necessary to make the automotive body assembly more adaptable, easier to install and more economic on space. This can be achieved with the presented concept (FlexLean) that introduces modular and highly flexible solutions based on modular, standardized components consequently in all levels of the automation (Negre & Legeleux, 2006). First of all the line is based on standardized and freely configurable cell modules. The complete line is made up of these highly flexible modules which are connected by a material handling track motion and standard communication interfaces only. The cells again achieve their high flexibility through a rigorous utilization of robot technology, not only for handling and welding with robots but also for clamping and fixturing systems. Key elements are here programmable flexible positioners, called FlexPLPs. These positioners can have depending on requirements different types of kinematics with one up to four axes and replace the tooling equipment used today for locating, handling and fixing car bodies or other parts. A special Deltapod kinematic is described in more detail that combines high accuracy and stiffness with an excellent compactness and light weight. To fulfill the wide range of requirements on the flexible positioners for the totally different tasks in the car body assembly they are built based on standardized components. A concept will be