The main problem encountered in the development of a truly flexible assembly cell is the requirement for complex and expensive fixturing and orientating devices that enable correct assembly from bulk storage. Each part has to be correctly fed and aligned prior to assembly. Whereas a similar problem encountered in Flexible Machining Cells (expensive set-up downtime) was overcome by off-line set-up, no solution to the Flexible Assembly Cell problem exists as yet.
This paper outlines the implementation of a truly flexible assembly cell to overcome the problem of expensive tooling that is required as products change or as new products are introduced. The proposed system is based around a tactile array assembly sensor, which will be capable of determining the shape (outline) and weight of the particular part present. The parts are fed in bulk to the assembly sensor and identified. The type and orientation (position) of the part is then identified by a database containing all components. The part is subsequently picked up by the control system of the assembly cell (robot arm) and assembled in the correct way. The system will also be part of a sophisticated MRPII system to integrate it into an overall CIM structure. It is hoped to develop a low cost method of parts identification that removes the need for expensive tooling within an assembly cell.