Industrial Robot Programming

Abstract: Industrial robots play a key role in manufacturing systems. Robots are distinguished from other types of machinery mainly on the basis of their programmability and ability to be adaptable to different tasks. The use of computer control to achieve desired flexibility implies that software issues for embedded control systems are central for the applicability and utilization of the equipment. The structure of control systems today, however, limits the applicability of robots, thus leaving many human unfriendly operations to be performed manually. This thesis takes a problem oriented approach, without enforcing use of formal methods. Considering industrial demands, such as computing efficiency and simple factory-floor operation, a layered system architecture and technical solutions to accomplish it are proposed. A notion of user views is introduced as the basis for definition of the layers; the layers support programming on levels ranging from implementation of motor control and up to end-user programming. An experimental platform, built around industrially available robots, has been developed. Specially developed hardware interfaces and reconfigurations of the original (ABB) system permits control and programming even of the low level motion control. Run-time efficiency within the proposed open and layered system was achieved by a new concept called actions. Actions are pieces of compiled code that, by use of certain compiling and linking techniques, can be passed as parameters between the layers. The required interplay between application specific programs and built-in motion control could therefore be accomplished. A number of case studies and results from ongoing experimental evaluation indicate that the proposed control system principles are very useful also in an industrial context.