The mean number of elevator door reversals, .mu., in groups of related door reversals, and the standard deviation, .sigma., 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 .mu.+3.sigma., , is medium if two out of three recent reversals exceed .mu.+2.sigma., 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'(S/C), that any component, C, will result in a symptom, S, (where S=first and second notable features in a related group and the accompanying floor factor, F) are provided by experts; the probability of P'(C) of any failure being of any given component is determined from failure history; and an estimated probability, P'(C/S), that symptom S is caused by component C is given by: ##EQU1##
RELATED APPLICATIONS
Related subject matter is disclosed in U.S. patent application Ser. No. 09/567,845 now U.S. Pat. No. 6,330,936, filed contemporaneously herewith.
Method for telemonitoring the condition and state of an elevator and for determining its need for maintenance by performing an automatic test run of the elevator car (1) in the elevator shaft (2) to collect data for use in an elevator telemonitoring process. The method of the present invention is characterized in that the aforesaid test run comprises a number of automatic test run cycles synchronized with respect to each other.
A monitoring system for monitoring doors such as a shaft or cabin door, of a lift installation includes a sensor element associated with the doors for monitoring the state or position of the door. An evaluation system is connected to the sensor element and evaluates the sensor signals. The evaluation system can perform continued evaluation in short time intervals in order to provide a continuous record of the state of the monitored doors and temporal changes in the signal characteristics of the sensor signals.
Variable thresholds (662, 663) are generated in response to an average defect rate (669, 690) generated under certain conditions (683-687, 696-698), excesses of which can set an internal flag (670). If an information request (720) or service personnel visit to the elevator site (721) occur, the internal flag, or the upward adjustment of the average defect rate (691) can generate a maintenance flag (773) which ultimately results in a maintenance recommendation message related to the particular parameter having a notable defect.
Transport system (2), comprising a controller, a drive motor and a safety switch (18) that is connected to a safety-related part (8, 10) of the transport system (2) and is able to distinguish between a safe state of the transport system (2) and an unsafe state of the transport system (2), where the safety switch is connected to the controller in order to interrupt the power to the drive motor in an unsafe state, characterized by the fact that the safety switch (18) is realized so that it is able to also detect a warning state in addition to the safe state and the unsafe state.
