WO1996008437A1

WO1996008437A1 - Procedure for safeguarding the operation of an elevator

Info

Publication number: WO1996008437A1
Application number: PCT/FI1995/000507
Authority: WO
Inventors: Aki Tamminen; Petri Huotari; Kimmo Heikkilä; Reima Reinvall; Juha Nieminen
Original assignee: Kone Oy
Priority date: 1994-09-16
Filing date: 1995-09-18
Publication date: 1996-03-21
Also published as: AU3389595A; FI944294A0; FI944294A

Abstract

The invention relates to a procedure and an apparatus for centralized organization of the maintenance operations required by the control and operating components of an elevator. Event data related to maintenance operations, descriptive of the functions of the elevator, are stored in a memory provided in an operator. These data are used to produce analyzed and/or organized information to be utilized as a means of maintenance.

Description

PROCEDURE FOR SAFEGUARDING THE OPERATION OF AN ELEVATOR

The invention relates to a procedure for centralized organization of the maintenance operations required by the control and operating devices of an elevator, which control and operating devices are connected via a serial communication network to an operator interface linked to the elevator control unit. The invention also relates to an apparatus for centralized organization of the maintenance operations required by the control and operating devices of an elevator, which control and operating devices are connected via a serial communication network to an operator interface linked to the elevator control unit.

Especially in a decentralized elevator control system, the elevator control apparatus comprises numerous electrical components as well as electronics and software controlling their operation. The control components in modern systems contain intelligent and self-regulating functions.

Abnormal functions occurring during operation are not neces¬ sarily transmitted to other parts of the elevator control system or even to the elevator control unit unless they have an effect that essentially restricts the normal operation of the elevator. In both centralized and decentralized systems, preventive maintenance has been the method used to prevent faults before a dramatic failure of elevator operation occurs. At certain intervals, elevator components susceptible to failure have been tested by a serviceman. Similarly, certain parts have been replaced at given intervals on the basis of their failure frequency.

This method has several drawbacks, which is why the resources devoted to maintenance are not in proportion to the benefit achieved. For instance, during each service visit to the elevator site, the serviceman has to check numerous components whose failure frequency does not require this. Besides causing a waste of time, this is also frustrating and detrimental to working motivation. On the other hand, a component having a lower failure frequency may fail at a time considerably in advance of its probable failure date. In this case, the hazardous part may remain unrepaired during normal maintenance and before it interrupts the operation of the whole system.

The number of electrical components contained in a decen¬ tralized control system is multiple times larger than in conventional solutions, and the components have their own processors and possibly a separate electricity supply. If it is important in traditional single-process systems to distinguish between different starting situations, at least between normal/abnormal operation, then in multi-component systems a capability to make such distinctions is even more important.

It must be possible to save the elevator performance data before the elevator is delivered to the customer, so that changes in performance can be compared in connection with subsequent service visits. The performance of the elevator must be in accordance with the requirements when it is delivered to the customer.

In a decentralized elevator control system, faults can be detected in all components of the control system. To make it possible to form a general view of a defective system, all failure information produced by the system must be available to the operator via a centralized process. To ensure that a correct general view is formed, the faults reported by the various parts of the system must be arranged in correct chronological order when they are presented to the operator.

The object of the invention is to improve preventive elevator maintenance especially in the case of a decentralized elevator control system. To achieve this, the procedure of the invention is characterized in that data about events related to maintenance operations on the elevator, descriptive of the functions of the elevator, are stored in a memory provided in the operator interface and/or in conjunction with the control and operating devices, said data being used to produce analyzed and/or organized information to be utilized as a means of maintenance and that the inrofmation is readable via a display or printer connected to the operator interface. Correspondingly, the apparatus of the invention is characterized in that the operator interface is provided with a memory in which it is possible to store event data related to maintenance operations, descriptive of the functions of the elevator, and a processor by means of which the data collected can be processed so as to give them a form that makes them usable as a means of maintenance and readable via a display or printer connected to the apparatus. Other preferred embodiments of the invention are defined in the subclaims.

The invention makes it possible to carry out maintenance operations in accordance with the real failure risk. Therefore, more effective maintenance is achieved and the serviceman is able to concentrate on essential items. At the same time, continuously updated information is obtained about the condition of the elevator and its various parts as well as the need for replacement of components. Product development can also be directed towards areas showing the most deficiencies and the highest failure potential.

According to an embodiment of the invention, in analyzing the system, a distinction is made between situations where the supply of electricity has been disconnected from the main voltage supply and situations where disturbances in elevator operation are caused by temporary disturbances in the operating voltage. This makes it possible to recognize many faults that are difficult to detect, because different starting situations can be distinguished from each other. At the same time, much more reliable information is obtained about the dependability of the system.

In a decentralized elevator control system, faults can be detected in all components of the control system. This has been carried out with the the processors installed to the devices of the elevator system. E.g the call units and display units have so called "intelligent" features. To make it possible to form a general view of a defective system, all the failure information produced by the system must be available to the operator via a centralized process. To ensure that a correct general view is formed, the faults reported by the various parts of the system must be arranged in correct chronological order when they are presented to the operator.

In the following, the invention is described in detail by referring to the drawings, in which

- Fig. 1 ^resents an operator interface terminal, and

- Fig. 2 illustrates the control hierarchy between the operator interface and the elevator control system.

As shown in Fig. 1, the terminal 11 of the operator interface (OPI) comprises a keypad 12 for the input of operation commands to the elevator units. The instructions and commands given by the operator and the elevator control system can be read on a display 13. The display is also used to present instructions relating to maintenance and data describing the condition of the system. The terminal is also provided with display units indicating the operation and status of the elevator and its components, such as indicators representing the car calls 14, door operation 15 and car position. The terminal is further provided with a connector 16 allowing a memory card 17 to be inserted into the terminal. The connector 16 is linked to the internal address and data bus of the terminal. The operator interface can be used to input elevator control commands corresponding to normal landing and car calls or open/close control of the door. When a personal memory card is used, the authority of use and possibilities of access to information are increased in accordance with the rights recorded on the card. The operating mode of the elevator can then be changed as required to include operating modes differing from normal operation.

However, the operation of the elevator is always controlled by the elevator control system as illustrated by the example in Fig. 2, representing the elevator control hierarchy. Fig. 2 illustrates data transfer by the software controlling door operation. The elevator control unit 22 is connected to the operator interface 11 via link 24, and via link 26 to the processor 28 executing the application program controlling door operation. Between the operator interface 11 and the application 28 there is only a data transfer link 30, but no control link.

Before the elevator is taken into use, it is supplied with elevator-specific operating values. The data are preferably supplied via the operator interface using a memory card on which the information relating to the particular elevator installation has been recorded. After verification of the authority of use, the time and date are set, whereupon the OPI requests a memory card containing the installation- specific information when the relevant function has been selected. The installation data are stored in non-volatile memory. The operator interface activates an elevator configuration controller, which sends the configuration data to all components of the elevator and reports the operations to the operator interface. The configuration controller also checks the data for correctness. After installation of the preparatory information, the setting data are installed. The values of the elevator performance data are stored by starting via the operator interface the relevant function, which causes the elevator to be driven according to a given sequence, stopping at each floor. In this connection, the performance of the elevator in different operations is measured and the reference data are saved, to which the performance values of the elevator are later compared.

The comparison of the elevator performance is effected in the same way. In connection with a service visit, the installer starts performance comparison from an operator interface in the elevator control panel. This function involves running the elevator according to the same sequence as in the performance value measurement/saving function. Components with diagnosing facilities measure the current performance and if they detect a fall in performance, they report this by displaying a "Disturbance" message on the operator interface.

The operator interface is provided with a non-volatile memory where the history data for all failures that have occurred in the operation of the components of the elevator control system are stored. The history data are recorded separately for each function by collecting the failures e.g. in the elevator drive, door control and power supply in a statistics calculator provided in the node of each function. These data are processed using a diagnostics control system and stored in the non-volatile memory. After a break in the supply of power, these data are read from the memory into the relevant node.

For instance, the door control system comprises several nodes which supervise different functions, such as door open times, re-opening due to safety edge action, re-closing of the door after an unsuccessful closing attempt, etc. These data are accumulated in statistics and processed according to certain criteria. When a memory card entitled to serviceman authority is fitted in the operator interface, the processed failure statistics are output to the operator interface display or to a printer connected to the interface. A condition test can be started from the operator interface or automatically by inserting a memory card entitled to serviceman authority.

In a decentralized elevator control system, each component of the control system generates failure messages about the failure conditions it detects. Depending on where the component is placed in the control hierarchy, the faults detected by it may be of various kinds: A component controlling a physical device detects disturbances in the operation of the device, a component placed higher up in the control hierarchy may detect e.g. synchronization errors in the operation of the devices at a lower hierarchy level. All the failure messages generated are stored by a centralized method in a battery-backed memory of the elevator computer. A time-stamped message transmission mechanism provided by the data transmission software ensures the correctness of the chronological order of the failure messages. In this way, a correct general view of the condition of the system is achieved.

By distinguishing different starting situations from each other, it is possible to have components that cause occasional operation failures repaired by the serviceman. The number of electrical components in a decentralized control system is multiple times larger than in conventional solutions, and the components have their own processors and possibly a separate electricity supply. Even in traditional single-process systems it is important to distinguish between different starting situations (at least normal/abnormal operation) , but in multi-component systems a capability to make such distinctions is even more important. Many faults that are difficult to locate can be detected if different starting situations can be distinguished from each other. At the same time, much more reliable information is obtained about the dependability of the system. All the cards in the decentralized control system use a commo 24 V voltage supply. In analyzing the system, it is importan to distinguish between situations where the supply o electricity has been disconnected from the main voltage suppl and situations where disturbances in elevator operation ar caused by temporary disturbances in the operating voltage. Eac device has its own monitoring system (a "watch-dog"), whic works as follows: Upon start-up, each process has to keep monitoring routine running. If any one of the processes i incapable of doing this, corresponding data is stored i another part of the system and the component is restarted. After the device has been started, the data in question i checked to see if the failure was due to intentional resettin of a device. Another analyzing routine is as follows. Th operating voltage is monitored to establish whether it fall below 18 V, producing a so-called NMI interrupt. The voltage i monitored to see if it remains above 10 V. When the operatin voltage again remains over 18 V for five seconds, a check i made to see if it remained continuously above 10 V, in whic case the failure was one of voltage supply, not a norma starting situation. After this, the device is reset.

According to the system, all faults and events which hav occurred in the operation of each device can be checked by th elevator serviceman. For each device there is a separate node, and these contain several functions on which statistics are compiled. For example, the door node comprises statistical dat about the operation of an optical passenger detector, about th operation of a door pressure limiter, re-opening of the doo due to safety edge action, re-closing and door times. A message indicating malfunction of the optical passenger detector is transmitted if the detector is active but there is probabl nobody near the elevator since the light cells remain inactive. The numbers of times the elevator and landing doors are re-opened and re-closed are recorded e.g. for every 100 closing operations. The closing and opening data indicates the number of times the doors have been closed and opened. The door time data comprises door time comparison data and counters for the calculation of average opening and closing times. If the reference value is exceeded, the door node registers corresponding data and transmits it at certain intervals to the operator interface for storage in the non-volatile memory.

Other functions for which event and failure statistics are maintained include driving of the elevator (drive to landing, correction drive, departures/stoppages, drive time counter) , power supply (temporary breaks in the supply of power), availability of the elevator (normal operation, servicing, malfunction, special operation) , elevator operation history

(report of operational modes) , network malfunctions, temperature variations (in machine room, control panel) .

According to the invention, the operator interface of the elevator contains a function called physical examination of the elevator. When the serviceman activates a physical examination via the OPI, the OPI gives the serviceman statistical information in a processed form, usable in the first place for the benefit of preventive maintenance. Moreover, the OPI informs the serviceman as to when and at which level of detail the physical examination should be carried out.

Preventive maintenance operations on an elevator are carried out on the basis of the information supplied by the OPI and the real measured data stored in its memory. Moreover, analyzed information about the system, based on measurement of the elevator functions, is available. The measurements performed bear a clear correlation to the need for preventive maintenance. In addition, the OPI suggests a date when a physical examination should be carried out, thus freeing the serviceman of the superfluous task of checking the preventive maintenance indicators. Based on the information provided, the serviceman can also adjust his estimate of future needs for repairs.

The invention has been described above by the aid of some of its embodiments. However, the presentation is not to be regarded as constituting a limitation, but the embodiments of the invention may be varied within the limits defined by the following claims.

Claims

1. Procedure for centralized organization of the maintenance operations required by the control and operating devices of an elevator, which control and operating devices are connected via a serial communication network to an operator interface linked to the elevator control unit, characterized in that data about events related to maintenance operations on the elevator, descriptive of the functions of the elevator, are stored in a memory provided in the operator interface and/or in conjunction with the control and operating devices, said data being used to produce analyzed and/or organized information to be utilized as a means of maintenance and that the inrofmation is readable via a display or printer connected to the operator interface.

2. Procedure as defined in claim 1, characterized in that the basic settings related to the operation of the elevator are stored in memory during the start-up of the elevator.

3. Procedure as defined in claim 1, characterized in that functions deviating from normal operation of the elevator and related supplementary information are stored in memory.

4. Procedure as defined in claim 3, characterized in that elevator status and failure data associated with error conditions are processed in the operator interface and that the material is accumulated in statistics and analyzed on the basis of predefined criteria.

5. Procedure as defined in claim 4, characterized in that statistics on measured data are maintained by a processor associated with the elevator control system and when it is necessary to start an analysis of the statistical data, this is indicated by a notice given via the operator interface.

6. Procedure as defined in any one of the preceding claims, characterized in that when deviations from normal operatio occur in the starting situation, the status of the devic associated with the abnormal operation is registered and, i necessary, the device is reset.

7. Procedure as defined in any one of the preceding claims, characterized in that each component of the control syste generates failure messages about the failure conditions de- tected by it and these messages together with data indicatin the time of occurrence are stored by a centralized method i the memory of the elevator computer.

8. Apparatus for centralized organization of the maintenanc operations required by the control and operating devices of a elevator, which control and operating devices are connected vi a serial communication network to an operator interface linke to the elevator control unit, characterized in that th operator interface is provided with a memory in which it is possible to store event data related to maintenance operations, descriptive of the functions of the elevator, and a processo by means of which the data collected can be processed so as to give them a form that makes them usable as a means of maintenance and readable via a display or printer connected to the apparatus.

9. Apparatus as defined in claim 8, characterized in that it comprises memory and processor units for the storage and transmission of event data, said units being placed in con- junction with the elevator components.