WP6-Brochure-E4 brochure - ELA European Lift Association.

lunch. Between these peak periods, during the morning and the afternoon, there is an
interfloor traffic demand, which prevails during most of the working day.
Figure 3‐23. Classical traffic demand pattern for an office building [11]
A number of traffic control algorithms have been developed that define the strategies
undertaken in order to optimise the use of grouped lifts by, for example:
• minimising passenger’s waiting time
• minimising passenger’s journey time
• minimising the variance in passenger’s waiting time
• maximising the handling capacity
• minimising the energy consumption
Nowadays, traffic control systems rely on more than one algorithm or program to allocate lifts
to landing calls, depending on the pattern and intensity of the traffic flow. For the selection of
the appropriate algorithm, a traffic analyser assesses the prevailing traffic conditions. Modern
traffic controllers can use artificial intelligence techniques – artificial neural networks, fuzzy
logics and/or genetic algorithms – to enhance the service’s effectiveness.
The controller can perform even better if the destination of the passengers is known prior to
them boarding the lift. With this purpose, hall call control systems were developed. These
systems work by replacing the conventional up or down buttons near the lift doors with
consoles located in the building’s lobby. Passengers enter their destination as they go in the
building and are immediately dispatched to a lift servicing their destination. Passengers are
thus grouped by destination, significantly reducing starts/stops and travel time. Since the
controller has broader information on the variables at stake, it is able to make more intelligent
decisions.
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