GB1501402A - Elevator system - Google Patents

Abstract

1501402 Elevator control system WESTINGHOUSE ELECTRIC CORP 4 April 1975 [16 April 1974] 13884/75 Heading G3N An elevator control system changes the lift speed pattern, e.g. acceleration, maximum speed or jerk, in response to the intensity of demand. This is intended to flatten power demand curves and reduce I<2> R losses during periods of light traffic. One or all of the cars 11 can be switched between the high or low traffic mode but switching only occurs when it is standing at a floor, not in mid flight. The mode is then maintained for a predetermined time to prevent too frequent switching. Traffic intensity is sensed directly by counting the number of car calls 48, corridor calls 50, the cars load relative to a rated load 46, the individual or cumulative times for which corridor calls have been registered, the assignment of a car to a priority call such as a timed out call or an unsatisfied demand for an available car. It can also be sensed indirectly using a system clock 44 synchronized with anticipated traffic peaks. The car 11, Fig. 1, is driven by motor 1 controlling unit 10. Car and corridor calls are recorded in units 32, 34 respectively, and speed pattern generator (38) Fig. 7 (not shown) controls drive control 40 for motor 1. A pattern modifier 42, described in detail, Fig. 3 (not shown), receives signals relating to intensity of demand and modifies the speed pattern when necessary Figs. 2A-2C (not shown). Other embodiments for bank or single car modifiers are described Figs. 5 and 6 (not shown).