Dynamic scheduling elevator dispatcher for single source traffic

Abstract

A elevator system including a group controller for controlling the dispatching of elevator cars to the lobby. The group controller predicts lobby single source traffic for short periods. When the predicted traffic is below certain limit, cars are assigned to a lobby hall call on demand after hall call registration. When the predicted traffic is above certain limit, cars are assigned to the lobby hall call at intervals. Accordingly, car assignment is scheduled at those intervals. The traffic threshold at which the scheduled mode is activated and the traffic threshold at which it is deactivated is learned by the system. The schedule interval is varied based on predicted traffic and predicted round trip time of the cars. The number of cars assigned and sent to the lobby is varied based on predicted traffic. In order to avoid oscillations in selecting the service mode, proper delays are used to activate and deactivate the scheduled service.