Interleaving dynamics in autonomous vehicle storage and retrieval systems

A state equation model is proposed for predicting the proportion of dual command cycles in autonomous vehicle storage and retrieval systems that use interleaving. This proportion is used to estimate storage and retrieval cycle times, system utilization and throughput capacity for alternative system design profiles defined by the number of storage aisles, storage rack height and depth, the vehicle fleet size and the number of lifts used for vertical movement. The state equation model enables the user to explicitly trade off model accuracy and computational complexity in the pre-engineering or 'concepting' stage of system development. A sample problem is used to demonstrate the model.