Cluster Motion of Multiple Elevators and Indices Related to the Transportation Efficiency Studied in a Discrete Model Simulation

Abstract

Elevators are familiar transporting systems exhibiting nontrivial out-of-equilibrium behaviors like the cluster motion in which multiple elevators arrive without much time between them. In this study, especially focusing on the interaction which occurs between elevators unintentionally and spontaneously and causes the cluster motion, we investigated the dynamic behavior of elevators during the down peak period by using a discrete model. We introduced a control parameter that changes the proportion of passengers who can get in an earlier-arriving elevator and numerically simulated the dynamics of the elevators. We examined the order parameter, the round-trip time, and the number of passengers transported in a single round trip. The cluster motion emerges when both the proportion of passengers who can get in an earlier-arriving elevator and the inflow rate are not small. In this condition, the round-trip time is short, and the number of passengers transported in a single round trip is small. Those results indicate that arriving without much time between elevators does not directly reduce the efficiency contrary to our intuition. In addition, we also investigated the response of an elevator to the external force by performing the control operation of one of the elevators.