Research and Development in Robotic Systems

Flexible Manufacturing Cell for Combined Laser Machining with Adaptive Gripper System (koLas)

Present robot systems are normally designed for a certain task. Their reconfiguration necessitates complex reprogramming or modification by operators.

In the future, robots will be reconfigured automatically during their operating life. This will require robot hardware and software capable of autonomously adapting to changes in boundary conditions.

Project Objective

The joint project koLas concentrated on developing a flexible robot cell that applies 3D-laser cutting and welding in any rapidly changing sequence to manufacture complex sheet metal components. In addition to rapidly switching processes, self-configuring clamping and gripping systems are needed.

Project Foci

Gripper systems for sheet metal machining are usually special designs for specific components. Their development is complex and each individual component requires a different one. They are assembled from numerous profile elements or made of a special welded frame on which a number of vacuum suckers or gripper jaws are attached. The minutest change in a component, e.g. by different types in auto body manufacturing, often entail redesigning the complete gripper system.

In the koLas project, the Fraunhofer IFF developed a flexible gripper arm for robots, which can replace many different gripper systems in flexible manufacturing and assembly processes. The gripper arm is constructed of modular elements, which may be combined as desired by lockable swivel, prismatic and ball joints. The robot and a specially developed path planning software are used to reconfigure the gripper arm for a different component. The robot loosens the clamped joint and moves the gripper arm on an automatically calculated path into a new configuration while the free end of the gripper arm is locked in a stationary point. Thus, the flexible gripper arm facilitates rapid conversion to changed component geometries without the work of manual conversion.

The gripper arm’s high adaptability can be used for more than sheet metal laser machining. It can also increase flexibility in numerous assembly jobs.

The joint project koLas was funded by the Federal Ministry of Economics and Technology’s InnoNet program (Ref. No. IN-5529) and supported by the project sponsor VDI/VDE-IT Berlin. The Fraunhofer IFF coordinated the project.