Simulation and optimal control tasks in production planning and virtual commissioning

Duration

from april 2001 until end of 2012

Project leader

Ingo Bremer

Cooperation

Rücker EKS GmbH , Weingarten

Introduction

In automotive industry with every model generation the pressure to shorter ,,time to market`` becomes higher. This does not only have large effects on the development of construction units, also the time for planning and realization of production systems is permanently shortened. The growing variance and the shorter life cycles of the models as well as the demand for more flexibility form here enormous conflicting aims.

In this context the concept of virtual commisioning of production plants represents the consistent advancement of the digital idea: Instead of focusing on computer aided construction of products and equipments (CAD) now complete production plants and their interactions are simulated and visualized dynamically. Expensive hardware tests at the real production plants (e.g. commissioning, configuration and test of cooperating robots) as well as possible crashs can be ommitted in such a way by shifting to the virtual level.

Basics

The software INVISION developed by the Rücker EKS GmbH in co-operation with WIAS permits the holistic and close-to-reality simulation of the systems and ensures already in an early production planning stage process security and production quality. Production interruptions are reduced, the quality will be increased and the costs decreased. The modularly developed system allows for the simulation of production plants in real time as well as for virtual commissioning. Not only robots are represented and animated, but all substantial mobile mechatronical components and materials. Apart from the verification of the work flow control the Virtual Reality environment offers also the possibility for collision analysis.

The software related basis for the VR-Rendering-engine forms the OpenGL Performer LIBRARY of SGI.

Challenges

• The entire inventory of a production plant including hall and materials must be set in (VR-),,Scene``.
• Many dynamic objects must be simulated in parallel and in real time. While in reality one arithmetic and logic unit (CPU) for the movement control is responsible for one robot, in VR-simulation one unit takes this task for many elements.
• The original 3D CAD-models are not performance-optimized and can be very expensive (triangle number usually within the range with six digits). Such triangulated surfaces in industrial models are unsuitable for the efficient implementation of complex mathematical methods. Hence, a pre-processing with correction and reduction of the user models is necessary.
• Development of a generalized robot programming model with import and/or conversion possibilities for the respective controlling languages of different manufacturers.