Otis Elevator Company

Robert H Mashiak

Chouhwan Moon

Juan A Lence Barreiro

Harry Z Huang

Ronald R Pepin

Gary L Freeland

Sanjay Kamani

Patrick Lusaka

Jean-Marie Rennetaud

The mean number of elevator door reversals, &mgr;, in groups of related door reversals, and the standard deviation, &sgr;, from the mean, are used to determine the likelihood that door reversals are caused by passenger interference; the likelihood is low if a recent number of reversals exceeds &mgr;&plus;3&sgr;, , is medium if two out of three recent reversals exceed &mgr;&plus;2&sgr;, and otherwise is high. The floors at which related notable elevator features occur are compared to determine a floor factor, F, depending on whether the notable feature occurs only at one floor or at more than one floor. Estimated probabilities, P&prime;(S/C), that any component, C, will result in a symptom, S, (where S&equals;first and second notable features in a related group and the accompanying floor factor, F) are provided by experts; the probability of P&prime;(C) of any failure being of any given component is determined from failure history; and an estimated probability, P&prime;(C/S), that symptom S is caused by component C is given by:

Service information derived from elevator operational parameters

Elevator events and conditions are monitored so as to determine features which are notable with respect to service including repair and maintenance, a name label is stored chronologically in a log upon each occurrence of a notable feature. Attributes of the feature stored chronologically with the feature, may include the date and time, the duration of the feature or a preceding condition, the point of time in a run when the notable feature occurred, the direction of elevator car travel and the floor location of the elevator related to the notable feature. Separation markers are generated to separate notable features which relate to each other from those that do not, each marker having floor number, time and date stamps and the duration between the first feature related thereto and the last feature related thereto stored chronologically therewith. Features include door reversals, loss of non-door safeties, failure making door lock switches, door rebound, doors open too long, and doors open in flight.

Elevator behavior reported in occurrence-related groups

An apparatus and method for providing an elevator door performance result of an elevator door in an elevator door system which normally operates sequentially from state-to-state in a closed loop sequential chain of normal operating states is disclosed. A plurality of parameter signals provided by the elevator door system is monitored by the apparatus. The apparatus comprises: a door state sequencer for providing a performance measure; a module for providing a reference measure and an acceptable range; and an abnormal detection module for analyzing the door performance measure.

Monitoring of elevator door performance

Growing community of inventors

Somers, CT, United States of America

Robert H Mashiak