An integrated simulation framework enabling flexible robotic palletizing

Robotic palletizing requires the rapid generation of optimal packing plans and the corresponding robot programs within the tight time constraints imposed by mass customization and factory intralogistics. In this context, while the bin packing problem has been extensively studied in the literature, practical engineering tools that support flexible batch palletizing, from optimal packing definition to validated robot execution, remain limited. In this regard, the present paper proposes an integrated simulation framework that guides engineers in defining an optimal robotic palletizing process through a structured sequence of steps. Starting from the 3D model of an existing palletizing station and its input product mix, the framework, implemented as a set of interconnected Python modules within the RoboDK simulation platform, supports automated generation and assessment of actionable packing layouts, simulation-based verification of the robotic process, and generation of executable robot code that can be automatically transferred to the robotic palletizing cell within a Digital Twin oriented approach. An efficient heuristic method is introduced to solve 3D packing instances for box-type items on standard Europallets. The problem is initially formulated as a sequence of 2D packing problems solved through a Guillotine plus Best Fit strategy, iterating across layers to maximize pallet filling while improving load balancing. The framework is validated across multiple scenarios on an industrially representative case study involving a KUKA palletizing robot, a conveyor feeding system, and two auxiliary buffer pallets. Finally, an instruction streaming module enabling online execution of the validated code on the KUKA controller is presented. Overall, the results confirm the effectiveness of the proposed framework in accelerating process planning, virtual validation and programming activities while maintaining packing quality in realistic industrial scenarios.