Abstract

In a method for coordinating elevator group traffic in a building with one or more change levels constituting an end station for elevator groups operating above and below the change level, and in order to reduce waiting times in tall buildings, the control of at least some of the elevator groups operating on opposite sides of the change level is subordinated to a centralized control algorithm which, depending on the traffic condition, alters the control parameters for the elevator groups in such manner that, when the main direction of traffic is upwards, in order to serve the passengers of the elevators arriving from one side of the change level, either the elevators operating on the other side are caused to arrive more quickly to the change level to minimize the waiting time for the passengers arriving from the opposite side, and/or the departures of the elevators which have stopped at the change level are retarded to allow the passengers arriving from the other side to get on board, and that when the main direction of traffic is downwards, in order to serve the passengers of the elevators arriving from one side of the change level, either the elevators are caused to arrive quicker to the change level and/or the elevators on the other side are kept waiting to allow the arriving passengers to catch them.