ABSTRACT
This chapter reviews conventional lift traffic control systems and then discusses the general principles of computer-based systems and details of three traffic control systems. The concept of using existing traffic control algorithms, designed to be implemented in relay or solid state logic, is a quick way to obtain a computerised traffic controller. The first approach by the lift industry to the computer control of lift systems was the software implementation of the existing conventional control algorithms. Conventional algorithms possess limitations, and their adoption to computer use restricts the flexibility possible with a computer. The ETA control system can be expected to provide a good uppeak performance. During an uppeak, the obvious cost function to implement with call allocation is journey time. It operates by costing each allocation against an average journey time cost function. The ACA system presents a powerful capability to adapt to unbalanced and changing traffic circumstances.
