Copyright © IFAC Automatic Systems for Building the Infrastructure
in Developing Countries, Istanbul, Republic of Turkey, 2003
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THE MODELLING AND SIMULAnON OF ELEVATOR GROUP CONTROL SYTEMS FOR
PUBLIC SERVICE BUILDINGS
C.Erdem Imrak
l
, Mustafa OzkJnm
2
/Istanbul Technical University, Department of Mechanical Engineering
GumlLSsuyu, 34439 Istanbul, Republic of Turkey
Fax:2I2 2450795... E-mail: imrak@itu.edu.tr
2 Istanbul Technical University, Department of Mechanical Engineering
GumlLSsuyu, 34439 Istanbul, Republic of Turkey
Fax:212 24507 95... E-mail: ozkirimmu@itu.edu.tr
Abstract: Elevator traffic control systems have become more and more complicated
due to their nature of intelligence. Artificial intelligence methods employing neural
networks have been proved to be successful in many fields, such as process
modeling, pattern recognition and classification problems. They have also been
applied to basic problems in elevator traffic control systems, such as the prediction
and control of elevator movements. In particular, neural networks can offer better
solutions to the passenger call allocation process when compared to the classical
traffic control methods. Elevator control algorithms utilizing neural networks aims at
distributing the most suitable cars to the floors by considering the passenger service
demand. Neural networks can dynamically learn the behavior of an elevator system
and predict the next floors to stop, based on what has been learnt. In this paper the
neural network approach has been applied to DuplexfTriplex group control systems
for improving passenger waiting time and a lift simulation software has been
developed and implemented in order to assess the learning capability by measuring
the performance of the control algorithm. The lift traffic analysis have been carried
out by examining the simulation results obtained. Copyright © 2003 IFAC
Keywords: control system design, neural network, simulation, backpropagation,
learning algorithms.
I. INTRODUCTION
Computer based traffic control systems can assign
cars more effectively than the classical traffic control
systems, there exists, however, a limit to what can be
achieved. The main limit is the finite capacity of the
underlying equipment to handle the traffic demands.
Hall and car calls are often allocated to suitable cars
by taking into account of the minimum cost concept
that operates by allocating the call to the car with the
lowest cost amongst all the cars that are available to
serve. The criteria for determining a suitable cost
function depends on either quantity of service and/or
quality of service. The quality of service is a measure
of the lift capacity consumed to serve a specific set
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of calls, indicated by total journey times of all the
cars (Barney, 2003).
An excellent service capability of a lift system in any
modem public service building (PSB) is needed for
the efficient functioning of the building. In the
design of lift traffic and calculating the performance
of a lift system, the traditional method is to calculate
the round trip time (RTT), which relies on
calculating the average number of stops made (S),
the average highest reversal floor (H) and the
average number passengers carried (P) (Jenkins,
1992). Then the number, car capacity and the speed
of the elevators can be derived in order to provide a
reasonable interval (RTT / number of lifts) and five
minute handling capacity (300 x P / interval). The