We present an evolutionary modernization procedure for high-range elev
ator groups. From the control point of view, a modern group of elevato
rs consists of a large number of microcomputers and efficient communic
ation networks. The intelligent control nodes are distributed around t
he entire elevator environment: in the machine room, in shafts, in car
s, and in lobbies. Therefore, the elevator control network resembles a
n office computing network with truly evolutionary capabilities. This
is the case solely in the state-of-the-art installations. However, the
lifetimes of elevator control systems are typically 15-25 years, and
thus the system architecture of the currently operating elevator base
is highly different than that outlined above. Full modernization of a
large group of 4-8 high-rise elevators is always a major monetary inve
stment and also a remarkable temporary disturbance for the passenger t
raffic. In this paper, we introduce a novel modernization concept that
makes it practical to perform the modernization of an elevator contro
l system step-by-step. The main motivation of such an approach is to g
radually move from the old technology to the new one, and spread the r
equired investments over several years, as well as greatly reduce the
disturbances to the elevator users. Our new procedure defines a smooth
evolution path from the present system components to the intelligent
mechantronic structures. (C) 1998 Elsevier Science Ltd.