Computer assisted ergonomic assembly cell design

When designing or modifying an assembly cell, the question at hand is "What will it cost, and what will we gain"? This research features the evaluation of assembly cell variants, taking operator timing and ergonomics into account. For each assembly step requiring an operator e.g. using a screwdriver, the ergonomic score is evaluated by considering the (automatically generated) poses of the operator at the start and finish of each assembly action. Furthermore, throughput is estimated by applying Methods-Time Measurement (MTM) to an inverted kinematics model of a virtual operator. We present our findings on an industrial use case: the assembly of a 15 kg compressor. Starting from an existing cobot cell, alternative assembly cells, with an adjusted resource allocation and a modified cell layout, are evaluated. Besides the performance metrics, human design factors, that are hard to model mathematically, can be incorporated in the design by visualizing and experiencing the work cell in virtual reality. This allows to further fine-tune the cell design.