A Hierarchically Structured Knowledge-Based System for Welding Automation and Control

The paper presents the concept and prototype development of a hierarchically structured knowledge-based system (KBS) for coordinated control of a welding robot and a positioning table. The KBS is designed for continuous seam welding in an autonomous manufacturing environment. The structure of the KBS allows updating and installation of individual function and database modules such as those used for determining welding parameters and identifying constraints and parameters for robot and table controllers. The KBS is designed to plan the feasible table configurations and robot trajectories as well as to coordinate the movements of the robot and positioning table. The KBS has a modular structure which can accommodate multiple configurations of different types of robots and positioning tables within a flexible manufacturing cell. Initial testing has demonstrated the feasibility of integrated heuristic and algorithmic procedures for real-time applications. A fully implemented version of this KBS will enable a user to perform high quality welds in a relatively short period of time with (possibly) incomplete knowledge of the welding cell equipment. The KBS software is written in the C language and has been tested for real-time operations within a simulated welding cell environment.