DEVELOPMENT OF A KNOWLEDGE BASED CAD/CAM COMPONENT FOR OFF LINE PROGRAMMING OF RECURRING SENSOR CONTROLLED WELDING PATTERNS

Project Information

Grant agreement ID: RI1B0280

Start date 1 January 1989

End date 31 December 1992

Funded under

• Multiannual research and development programme (EEC) in the fields of basic technological research and the applications of new technologies (BRITE), 1985-1988

Total cost € 0,00

EU contribution No data

Coordinated by

FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Germany

Exploitable results

Computer aided arc welding

To avoid the disadvantages of the teach in method, a new knowledge based off line programming system for industrial robots has been developed. This system realizes the following advantages in comparison to the existing programming systems for arc welding: consideration of special requirements of arc welding problems and technology; adaptability of the programming system to the welding tasks, being specific for the welding application and the production site; easy and reliable integration of design data from computer aided design (CAD) systems; fast, semiautomatic and reliable generation of robot programs for similar work pieces and design variants, which often occur in welding production sites. The system incorporates welding specific and robot specific know how in the form of rules and thus gives the programmer of the industrial robot very useful support during programming. In detail, the following steps of robot programming are covered by this system: analysis and classification of the welding geometry based on CAD data; determination of welding parameters; planning of the welding sequence under process specific and manufacturing aspects; planning of the robot;s motion during the welding and between weldings; positioning of external robot axes and resolving of kinematic ambiguities; storage of the robot program in high level format in the relational database. The welding specific and robot specific know how arc stored in different knowledge bases designed to facilitate later modifications and extensions. The tasks of the first knowledge base are to determine the current robot cell configuration, to evaluate the CAD data and to classify the different welding tasks. After the selection of the proper welding parameters, an optimized welding sequence is determined by the next knowledge base. In the next module, the position of the robot on the external axes and the resolving of kinematic ambiguities are determined. After determining the collision free reachability of each welding, the following knowledge base generates the movement of the industrial robot from end of a welding seam to the beginning of the next one.