One4Many-StablePacker: An Efficient Deep Reinforcement Learning Framework for the 3D Bin Packing Problem

Abstract

The three-dimensional bin packing problem (3D-BPP) is widely applied in logistics and warehousing. However, existing learning-based approaches often neglect stability constraints and struggle to generalize across diverse bin dimensions. To address this, we propose a novel deep reinforcement learning framework, One4Many-StablePacker (O4M-SP). The primary advantage of O4M-SP lies in its ability to handle variable bin dimensions in a single training process while explicitly enforcing two types of practical stability constraints: support constraints, which ensure an item's bottom center lies within the convex hull of the underlying contact area, and weight constraints, which restrict the total vertical load on an item to its bearing capacity. Our training method introduces two innovative mechanisms. First, a weighted reward function integrates the loading rate with a novel height difference metric for packing layouts, promoting improved bin utilization via flatter packing configurations. Second, clipped policy gradient optimization with tailored policy drifting mitigates entropy collapse, encouraging exploration at critical decision nodes during packing to prevent premature convergence. Extensive experiments demonstrate that O4M-SP generalizes effectively across diverse bin dimensions and significantly outperforms baseline methods. Furthermore, the framework exhibits strong practical applicability by solving complex scenarios under strict stability constraints.