ABSTRACT
This chapter introduces the concept of lift traffic control. It presents the concept of single lift control and some of the rules associated with it. It overviews three classical lift group control algorithms that were used in the era preceding the use of microprocessors in lift traffic control. It is useful to examine the group control algorithms that were implemented in hard-wired relay logic controllers. The chapter shows that appropriate automatic traffic control systems can enable a single lift, or a group of lifts, to operate at very high efficiency, provided this is matched by high-performance, reliable electromechanical equipment. It analyses and discusses the main features available in the most representative conventional implementations of lift group control systems. The FS-PT system is unique among the classical traffic control systems as it considers time when making an assignment; the other algorithms only consider position.
