A technique for integrated modelling of manual and automatic assembly

The purpose of this paper is to describe a comprehensive modelling technique that supports the assembly of very complex products that require intensive use of both computerized worker guidance and automation. The modelling enables the planning of this complex process.

The proposed approach utilizes and extends typical product documentation (such as route cards and bill of materials (BOM)) to form hierarchical Petri net in a stepwise process. The suggested framework models the dynamic progress of the assembly process, and can generate route card instructions for manual operations, or ladder diagrams (LDs) for automation.

The model can help the generation of computerized control over route cards for manual assembly operations. For automated processes, the translation algorithm of the model to LD enables its application on currently available equipment (programmable logic controllers (PLCs)).

The proposed framework heavily depends on the BOM data quality. So it is crucial to verify that the BOM data is not ill-defined before applying the proposed framework. Future research could report on the implementation of this model in assembly processes, or suggest another modelling technique.

The model enables the integration of computer control over both manual and automated assembly processes. This enables seamless transition between these two very different operations. This ability carries the promise of reducing the cost of code generation and maintenance, and contributes to the progress towards more flexible automation.

This paper presents a new comprehensive modelling technique that may support planning, simulating, tracing, and controlling the assembly process. The technique for the first time integrates modelling of both manual and automated assembly operation.