Students and researchers at the Institute for Computational Design (ICD) and the Institute of Building Structures and Structural Design (ITKE) at the University of Stuttgart have again come up with an astonishing and unique research pavilion – nature once again provided the blueprints for the design and a KUKA robot once again played a key role in the implementation of this interdisciplinary research project.
INNOVATIVE PLANNING AND MANUFACTURING FOR NEW CREATIVE LEEWAY
The origins of the pavilion are to be found in parties, balls and exhibitions. Designed to be a temporary structure, the pavilion has always been an ideal subject for research. Architects, framework planners and structural engineers can test drafts and designs, materials and manufacturing methods on the test object on a large scale and under realistic conditions. Freedom of planning, liberated from building restraints and conditions of permanent use, brings out the best in engineers. It is therefore no surprise that Mies van der Rohe achieved global fame with his pavilion at the World Exhibition in Barcelona way back in 1929. To this day, it is regarded as a seminal work in the field of modern architecture.
Impressive designs have also been produced at the University of Stuttgart as part of the ICD/ITKE research project run by Prof. Achim Menges and Prof. Jan Knippers. These include a pavilion made of curved particle boards with a thickness of just 6.5 millimeters in 2010, a pavilion comprising 850 unique individual parts based on the structural principles of the exoskeletons of sea urchins in 2011, and a pavilion imitating the bionic principle of the lobster.
The design of the latest research pavilion – that is futuristic and avant-garde in equal measure – is based on the characteristics of the elytra of flying beetles.
Bionics – creative technical implementation of biological archetypes
The integration of computer-based draft processes and the transfer of construction principles from nature to automated manufacturing processes with the aid of robots are of particular significance. In cooperation with biologists and paleontologists from the University of Heilbronn and colleagues from the Institute for Synchrotron Radiation (ISS) in Karlsruhe and the Institute of Textile Technology and Process Engineering in Denkendorf, the scientific research team from the University of Stuttgart – unrivaled in terms of innovation and interdisciplinary networking – is investigating the transfer of material and morphological principles from the realm of biology as a starting point for a new construction paradigm in the field of architecture. The results are intended to open up new creative leeway and provide an indication of the permanence of new facade designs.
Lightweight construction – inspired by nature
Robotic manufacture of fiber reinforced composite materials and the construction principles of biological fiber structures were the two dominant factors of this year’s ICD/ITKE pavilion. During the investigation of natural fiber reinforced composite structures, the elytra of flight-capable beetles provided a suitable example of material-efficient construction – particularly strong and stable, and yet economical in terms of material and weight. A double-shell structure with a curved geometry, with the upper and lower shells connected by pillar-like supporting elements. The arrangement and geometrical form within the shell of the beetle vary so greatly (depending on the specific loads involved), that comparative observations of various different species of beetle were required in order to identify (under a scanning electron microscope) fundamental structural principles and derive an underlying design.
3D models created using computer tomography formed the basis for 36 modules – with every one of them being unique. The task now, taking into consideration the capabilities of robotic production, was to develop a process for modular, double-shell, fiber reinforced composite structures with outstanding static characteristics, reducing the required mold construction to a minimum while at the same time allowing for geometric variety.
KUKA robots – perfectly wound
The solution: a coreless winding process in which glass and carbon fibers soaked in resin are wound onto frames guided by two cooperating KUKA robots of type KR QUANTEC ULTRA. The thin frames merely constitute the edges of the workpieces – the workpiece geometry is created by the interaction of the fibers that are freely located in space. The fibers initially form segments with a linear structure. New fibers are laid on top of fibers that have already been wound, resulting in an alternating form and linking the segments together to create complex curved surfaces.
Based on a simulation of the frictional connection of the overall structure, the number of fibers in each individual component and their alignment are calculated and transferred as a sequence of winding instructions for the robots. The winding syntax, the motion planning of the robots, the mathematical coupling of external axes and robots, and the control of the robots themselves have been implemented in a specially developed, integrated, digital planning and production process. It was possible to adapt the frames located on the two KUKA industrial robots to the different component geometries, thereby enabling the production of all 36 modules with a single robot tool.
Result: A structure manufactured fully automatically that enables an innovative, resource-saving, high-performance load-bearing design and component composition for architecture.
Up close and personal with robot technology
As patron and project sponsor, KUKA Roboter GmbH provides the university with the required robots and technical expertise. Project discussions with experts and user training courses are also on the program. The participants in the university research project appreciate the high precision and flexibility of the KUKA robots and their ease of programming. The Stuttgart engineers program the interface from the draft phase through to production. The data from the draft model and measurement results are transferred to machine code using KRL (KUKA Robot Language), thus ensuring a smooth digital information chain from the draft and static planning to material availability and machine control.
The University of Stuttgart already set up a RoboLab with its first KUKA robot back in 2010. In the prototype workshop, the students learn how to work with the robot while gathering experience in the field of research into new production methods in architecture. A new master’s degree course has even been set up, focusing on robotic production processes.