The handling of objects in automated processes is generally not considered to add value. Nevertheless, it remains a necessary component of automation, meaning that a great deal of effort is often invested in its project planning. The AsenBa research project, funded by the Baden-Württemberg Foundation, has developed approaches to automate the engineering process and thus minimize the effort required to plan the handling system.

Sensitive objects as a challenge for handling
The project focuses in particular on objects that pose a special challenge for the planning of handling devices due to their properties. These are sensitive two-dimensional objects such as textiles, which are easily deformed during handling. Depending on the manufacturing process, deformations are acceptable up to a certain level. This issue is therefore relevant, for example, in automated lightweight construction processes that process carbon fibers in the form of textiles, as well as in the clothing industry.

The design of a handling system for such cases is only possible for a person with a great deal of experience, is often done intuitively and even then is subject to a high degree of uncertainty. An engineer's response to such uncertainties is understandably oversizing. The result of oversizing is a handling system that uses more grippers than necessary and therefore weighs more. Particularly in the case of large two-dimensional objects, this oversizing leads to a disproportion between the weight of the component and the weight of the handling system.

The handling of objects in automated processes is a necessary component of automation, so that a great deal of effort is often invested in their project planning. © wbk

Automation of the handling design
The individual design of handling systems is realized in the AsenBa project using a design logic that draws on simulation results. This is made possible by the integration of finite element simulations (FE simulation), which can be used to calculate the sagging of textiles based on a gripper configuration. At the same time, however, the FE simulation is an expert tool, as the model requires a deeper understanding of the assumed boundary conditions and the resulting outcomes, both in terms of structure and interpretation. However, the aim of AsenBa is to deliberately reduce the complexity for the user.

This reduction is made possible by interaction with simple graphical interfaces. A guided web-based interface allows the user to enter all the necessary information for the automatic design. This information includes the assumed speeds and accelerations of the handling process, as well as the geometric shape of the object and the material properties. Describing the material properties poses a challenge. Exact models would require a large number of input parameters, the determination of which would involve a great deal of effort. The AsenBa project therefore attempts to make do with very rudimentary and simple data that can be determined quickly and easily by anyone.

Based on the input data, gripper arrangements are then calculated for two-dimensional components, which are then simulated. This is made possible by using approaches from the field of self-organizing maps. The algorithm attempts to place a defined number of grippers on the component. It then attempts to find an arrangement that satisfies the boundary conditions by adjusting the gripper positions. If this is not successful, additional grippers are integrated.

In order to not only calculate such gripper arrangements, but also to be able to test them in practical trials, a modular handling system was implemented in the project. The real special feature here is the gripper modules. These can be freely attached to the frame structure and contain the peripherals required to control the grippers themselves. Commands are received wirelessly from a central control system via integrated communication modules and implemented with the help of integrated compressed air valves.

We would like to take this opportunity to thank the Baden-Württemberg Foundation for funding the research project.

J. Fleischer, S. Coutandin, F. Ballier/as

wbk Institute for Production Engineering of the Karlsruhe Institute of Technology (KIT) © wbk

Briefly explained: The wbk
The wbk Institute of Production Engineering at the Karlsruhe Institute of Technology (KIT) is part of the Faculty of Mechanical Engineering. The three areas of manufacturing and materials technology, machines, plants and process automation and production systems, which are headed by Prof. Dr.-Ing. habil. Volker Schulze, Prof. Dr.-Ing. Jürgen Fleischer and Prof. Dr.-Ing. Gisela Lanza, are dedicated to application-oriented research, teaching and innovation in the field of production technology at KIT . www.wbk.kit.edu

Scientific Society for Assembly, Handling and Industrial Robotics (MHI e.V.) © MHI

Briefly explained: The MHI e.V.
The Wissenschaftliche Gesellschaft für Montage, Handhabung und Industrierobotik e.V. (MHI e.V.) is a network of renowned university professors - institute directors and chair holders - from German-speaking countries. The members conduct both fundamental and application-oriented research on a wide range of current topics in the fields of assembly, handling and industrial robotics. Further information on the society, its members and activities: www.wgmhi.de.