Designing and Testing Modular Karakuri Dynamic and Static Rack for Autonomous Material Handling Efficiency

Abstract

This study addresses the gap in modularizing Karakuri dynamic trolley racks and static two-level racks for autonomous material handling by developing an optimized design framework to enhance mechanical reliability and material flow efficiency. Two designs were proposed, Design-A and Design-B, with selection based on budget savings and design simplification for integration with Automated Guided Vehicles (AGVs). Mechanization analysis focused on critical mechanical components, while performance tests assessed box transfer times and speeds under loads of 5, 10, and 15 kg on dynamic trolleys and 0 kg on static racks. Design-B was selected for its 50% reduction in material usage, elimination of compressed air dependency, and a mechanical stopper system enabling simultaneous box movements, unlike Design-A’s sequential pneumatic process. Performance tests across Tracks B, C, D, and E revealed wooden boxes achieving higher final speeds (0.7-0.8 m/s) than plastic boxes (0.53-0.6 m/s) on Track B due to smoother surfaces, with speeds ranging from 0.25 m/s to 1.74 m/s across tracks, influenced by initial speed and queue position. Design-B’s swing mechanics and triggers ensured reliable, adaptable box movement with minimal oversupply risks. These findings validate Design-B as a cost-effective, scalable solution for autonomous material handling in lean manufacturing environments.