Yoichi Nagao

A Teaching-Free Robot System Utilizing Three-Dimensional CAD Product Data

The recent shortage of experienced workers and the trend toward better working environments have accelerated the introduction of robots into manufacturing sites. This in turn has highlighted the need for more efficient teaching methods of robots. Conventionally, industrial robots are taught online. With this method, the production line had to be halted at every teaching sequence, which adversely affects production efficiency. More recently, offline teaching has become common using computer-based robot models (Kobayashi et al., 2001). While off-line teaching does not stop the operation of the production line, teaching demand is intensive for the production lines where many different products are manufactured in small lots, leading to high operator workload and pushing up production costs (Nagao & Onoue, 2000). The authors have been engaged in research into an automatic NC data generator named Kawasaki Common Off-line NC data Generator (KCONG) (Nagao et al., 2000a). KCONG generates action data for a robot based on the design information from a three-dimensional CAD unit without the need for any human intervention or teaching. Recently, the authors have developed some teaching-free robot systems by combining KCONG with welding, cutting, painting and other industrial robots (Nagao et al., 2000b). This chapter introduces one such system, a teaching-free robot system for welding large box structures using KCONG, which was delivered to a client and is now operating successfully (Nagao et al., 2001).

Development of a teachingless robot system for welding a large-sized box-type construction

As a means of teaching operations to robots, the use of off-line teaching is increasing because it does not require the production line to be stopped. Off-line teaching, however, requires a certain amount of operator workload. To overcome this problem, Kawasaki Heavy Industries has developed an automated off-line teaching system known as KCONG (Kawasaki Common Off-line NC data Generator). In this system, which uses design data from a three-dimensional (3D) CAD system, a computer can automatically generate numerical control (NC) data that will describe the action of a robot, thus eliminating any involvement on the part of the operator. This system has been applied to an automatic welding robot system for a large-sized box-type construction.