Integrated sensor-based control system for a flexible assembly cell

A detailed discussion is presented of a number of important issues associated with an integrated sensor-based control system (ISBCS) for a flexible robotic assembly cell using a knowledge-based approach. The architecture of the system consists of several functional modules for perception, planning and control, and the actions of the cell's devices. These modules are: the user interface, product data model, task planner, knowledge-based system, cell organiser, sensory system, motion control, and an error detection and recovery module; all are linked together in a structure which is based on a three level, hierarchical, intelligent-machine architecture. The developed system in total is capable of performing various assembly tasks for different products on a single station, without the aid of jigs and fixtures to present the parts. The system can recognise and manipulate assembly parts which have any random position and orientation, and which are lying on any side or face. There are many important application areas where such systems would be of significant value and benefit. This research programme has explored a number of potential industrial applications? including assembly automation, inspection, and automatic sorting, and is awaiting full evaluation of the system through a series of industrial trials. (C) 1997 Elsevier Science Ltd.