Simulation study of RCS/R-systems with several robots serving one picking station

Abstract

Robot-based compact storage and retrieval systems (RCS/RS) are fully automatic storage systems operated by robots from above. Therein, goods are stored in plastic bins stacked on each other, resulting in a 'Last-In-First-Out' storage strategy within each stack. This ensures very high degrees of space utilization. If containers located further down the stack are required, the robots relocate those stored above the required one. RCS/R-systems can typically be found in e-commerce, the pharmaceutical industry, and food or spare parts trade. Besides the system parameters, many other factors, such as the number of robots or the grid size, influence the system's behavior. This paper focuses on the system's throughput and the optimum number of operating robots. A discrete event simulation (DES) in the SIMIO simulation program gained insights into design variants and operating modes.