METHOD AND MONITORING DEVICE FOR INFERRING A HEALTH STATUS OF CALL DEVICES IN AN ELEVATOR ARRANGEMENT

Abstract

A method for inferring a health status of call devices in an elevator arrangement uses a monitoring device for implementing the method steps of: determining elevator usage information by detecting: changing of an opening status of an elevator door, interrupting of a light curtain at an entry to an elevator car, and/or changing of a weight of the elevator car; determining elevator travel information concerning a starting floor and/or a target floor for an elevator car motion taking place antecedent or subsequent to the detected elevator event; inferring the health status of a monitored one of the call devices based on the elevator usage information and on the elevator travel information. The method allows determining the health status of call devices such as car call devices and hall call devices with a reduced number of sensors.

Claims

1-12. (canceled)

13. A method for inferring a health status of call devices in an elevator arrangement, the method comprising the steps of: determining elevator usage information of the elevator arrangement by detecting at least one elevator event, the detected at least one elevator event being one of changing an opening status of an elevator door, interrupting a light curtain at an entry to an elevator car, and changing a weight of the elevator car; determining elevator travel information associated with at least one of a starting floor and a target floor for motion of the elevator car taking place one of antecedent to the detected at least one elevator event and subsequent to the detected at least one elevator event; and inferring a health status of a monitored one of the call devices based on the elevator usage information and the elevator travel information.

14. The method according to claim 13 including excluding from consideration any information directly indicating an activation of the monitored call device when inferring the health status of the monitored call device.

15. The method according to claim 13 including inferring the health status of the monitored call device based on a probability value indicating a probability that the monitored call device has been activated within a predetermined time interval, the probability value being determined based on the elevator usage information and the elevator travel information.

16. The method according to claim 13 including gathering the elevator usage information and the elevator travel information during several subsequent trips of the elevator car and inferring the health status of the monitored call device based on the elevator usage information and the elevator travel information gathered for the several subsequent trips.

17. The method according to claim 16 including, for each of the several subsequent trips, deriving a trip specific probability of an activation of the monitored call device based on the elevator usage information and the elevator travel information, and inferring the health status of the monitored call device based on a combined probability of an activation of the monitored call device calculated from several of the trip specific probabilities.

18. The method according to claim 13 including when a health status lower than a predetermined limit value is determined for longer than a predetermined time period, generating a health information signal and submitting the health information signal to an elevator supervision device.

19. The method according to claim 13 including determining the elevator usage information by detecting a current position of the elevator car.

20. A monitoring device for inferring a health status of call devices in an elevator arrangement, the monitoring device being incorporated in the elevator arrangement and being adapted to at least one of perform and control the method steps according to claim 13.

21. The monitoring device according to claim 19 wherein the monitoring device is connected to at least one of a door contact for detecting the change in an opening status of an elevator door, a light curtain device for detecting the interrupting of a light curtain at an entry to an elevator car, and a load measuring device for detecting the changing of a weight of the elevator car.

22. The monitoring device according to claim 21 wherein the monitoring device includes or is connected to a positioning device for detecting a current position of the elevator car.

23. A computer program product comprising computer readable instructions which, when performed by a processor of a monitoring device, instruct the monitoring device to one of perform and control the method steps according to claim 13.

24. A non-transitory computer readable medium comprising the computer program product according to claim 23 stored thereon.

25. A method for inferring a health status of call devices in an elevator arrangement, the method comprising the steps of: determining elevator usage information of the elevator arrangement by detecting an elevator event, the detected elevator event being one of changing an opening status of an elevator door, interrupting a light curtain at an entry to an elevator car, and changing a weight of the elevator car; determining elevator travel information associated with at least one of a starting floor and a target floor for motion of the elevator car taking place one of antecedent to the detected elevator event and subsequent to the detected elevator event; gathering the elevator usage information and the elevator travel information during several subsequent trips of the elevator car; and inferring a health status of a monitored one of the call devices based on a probability value indicating a probability that the monitored call device has been activated within a predetermined time interval, the probability value being determined based on the elevator usage information and the elevator travel information gathered for the several subsequent trips.

26. The method according to claim 25 including excluding from consideration any information directly indicating an activation of the monitored call device when inferring the health status of the monitored call device.

27. The method according to claim 25 including when a health status lower than a predetermined limit value is determined for longer than a predetermined time period, generating a health information signal and submitting the health information signal to an elevator supervision device.

28. The method according to claim 25 including determining the elevator usage information by detecting a current position of the elevator car.

Description

DESCRIPTION OF THE DRAWINGS

[0051] FIG. 1 shows an elevator arrangement comprising a monitoring device in accordance with the present invention.

[0052] The figure is only schematic and not to scale. Same reference signs refer to same or similar features.

DETAILED DESCRIPTION

[0053] FIG. 1 shows an elevator arrangement 1 comprising a monitoring device 3 in accordance with an embodiment of the present invention. In the elevator arrangement 1, an elevator car 5 and a counterweight 7 are suspended by suspension means 9 comprising for example multiple ropes or cords. The suspension means 9 may be driven by a traction sheave 13 of the drive engine 11. Operation of the drive engine 11 is controlled by an elevator controller 15.

[0054] The elevator arrangement 1 comprises several call devices 20. For example, in the elevator car 5, car call devices 19 are included in a car operation panel 17. The car call devices 19 may be implemented using push buttons. For example, one push button may be provided for each of multiple floors of a building. On each of the floors including a starting floor 35 and a target floor 37, hall call devices 23 are provided for example in landing operation panels 21. Again, the hall call devices 23 may be implemented using push buttons. Optionally, two push buttons may be included in each hall call device 23 in order to enable indicating a direction to which the elevator car 5 shall travel after having stopped at the starting floor 35.

[0055] A passenger waiting for example at the starting floor 35 may press one of the push buttons of the hall call device 23 for indicating that the elevator car 5 shall come to this starting floor 35. When the elevator car 5 arrives at this starting floor 35, elevator doors 26 comprising a floor door 25 and a car door 27 may be opened. Generally, such opening of elevator doors 26 is detected using one or more door contacts 29. Upon opening the elevator door 26, the door contact 29 changes its switching state. Typically, the normally-closed door contact 29 opens when the elevator door 26 opens. The passenger may then enter the elevator car 5. Upon passing through an opening formed by the opened elevator doors 26, the passenger will pass through a light curtain generated by a light curtain device 31. Furthermore, upon entering the elevator car 5, a load measuring device 33 will detect a change in a load of the car 5.

[0056] The passenger may then select a target floor 37 by pushing one of the push buttons forming the car call devices 19. An information about the passenger's selection is submitted to the elevator controller 15 which then controls the drive engine 11 to displace the elevator car 5 towards the target floor 37. At the target floor 37, the elevator doors 26 open again and the passenger may leave the elevator car 5 again passing through the light curtain generated by the light curtain device 31 and at the same time lowering the weight of the elevator car 5 as detectable by the load measuring device 33. There is further a positioning device 34 for detecting a current position of the elevator car 5. This positioning device 34 could belong to or just connected to the monitoring device 3.

[0057] In order to monitor the call devices 20 and infer information about a health status of these call devices 20, elevator usage information and elevator travel information may be determined and may then be used for inferring the health status of a monitoring one of the call devices 20.

[0058] Particularly, for determining the elevator usage information, opening of the elevator door 26 may be detected using for example the door contact 29. Additionally or alternatively, interrupting of the light curtain at the entry to the elevator car 5 may be detected using the light curtain device 31. Furthermore, additionally or alternatively, changing of the weight of the elevator car 5 may be detected using the load measuring device 33.

[0059] Additional to detecting one of these elevator events for determining the elevator usage information, the elevator travel information may be determined for example by using information provided by further sensors or information provided by the elevator controller 15. Therein, the elevator travel information relates to an identity of the starting floor 35 or of the target floor 37 between which the elevator car 5 is displaced before or after the above-mentioned elevator event takes place.

[0060] By suitably processing and analyzing the determined elevator usage information and elevator travel information, the monitoring device 3 may derive information about a current health status of the call devices 20 in the elevator arrangement 1 without necessarily having direct access to these call devices 20 and/or without necessarily having to include any additional sensors into such call devices 20. Instead, the information about the health status of the call devices 20 may be derived solely based on measurement results provided by sensors or devices, such as the door contacts 29, the light curtain device 31 and/or the load measuring device 33, which are generally included in elevator arrangements 1 for safety reasons and which generally are easily accessible.

[0061] In the following, two exemplary implementations of the method proposed herein will be described.

[0062] In a first example, the method starts with the elevator car 5 initially standing at a known starting floor 35. The method then relies on tracking a sequence of elevator events including a status of door contacts 29, a status of load weighing and a status of the light curtain, in order to infer what type of elevator call has been and at which location.

[0063] Generally, when the elevator car 5 is stationary, its position is known. Any travel without an initial opening of the elevator doors 26 will typically register an existence of a floor call from a passenger.

[0064] Arriving at the target floor 37 allows the proposed method to log a successful call entry for the floor in question. A transition in the load weighing value sensed by the load measuring device 33 combined with an activation of the light curtain typically registers an entry of the passenger into the elevator car 5.

[0065] A subsequent trip in combination with an activation of the light curtain and a decrease in the weight of the elevator car 5 allows the method to infer that a car call was entered at the next destination.

[0066] Any change to the weight of the elevator car 5 allows the method to infer the boarding or disembarking of one or more passengers and a subsequent registration of other hall or car calls.

[0067] Another important characteristic of a behavior of an elevator may be related to a time the elevator doors 26 remain open when serving any calls. Typically, car calls elicit shorter door open times versus hall call due to an anticipated speed with which a passenger will leave the elevator car 5 once the elevator doors 26 are opened. A boarding passenger will possibly need to move towards the arriving elevator car 5 and be more likely to need additional time to board. Lastly, a confluence of car and hall calls may result in an even longer door open time and this information may also be used to infer the type of call being served.

[0068] Over the course of e.g. one typical day, all floors in a building are expected to be visited. This may allow the inference of the health status of all call devices 20.

[0069] If, for example, no single actuation of one of the call devices 20 in the building is detected during an entire day, this may be taken as indicating a problem in the health status of this call device 20, i.e. for example a malfunction. Upon detecting such reduced health status, a health information signal may be generated and may be submitted for example towards a remote elevator supervision device 41. At such remote elevator supervision device 41, the health information signal may be processed and, if deemed necessary, for example maintenance staff may be sent to visit the elevator arrangement 1.

[0070] In a second specific exemplary implementation, it may be assumed that the elevator car 5 is initially waiting at the starting floor 35 being for example the ground floor of a building. While waiting, the elevator doors 26 are closed and a load in the elevator car 5 is assumed to be zero.

[0071] Upon determining the elevator usage information, it may then for example be detected that no opening of the elevator doors 26 occurred and no change of the weight of the elevator car 5 was registered. From this information alone, it may already be inferred that probably the actuation of a hall call device 23 initiated the present elevator car trip. Furthermore, upon obtaining the elevator travel information indicating that the elevator car 5 travels to a target floor 37 such as the third floor of the building, it may be inferred that probably the actuation of a hall call device 23 in the third floor initiated the present elevator car trip. A probability value 39 indicating that this assumption is correct may be assumed to be for example 33%.

[0072] Next, it may be detected for example that the elevator doors 26 open for five seconds. Then, a light curtain is triggered and a load in the elevator car 5 increases by 30%. Based on this elevator usage information, it may be inferred that the probability 39 that an actuation of the hall call device 23 at the third floor initiated the elevator car trip may be assumed to be for example 66%.

[0073] In a next step, it may be detected that the opening status of the elevator doors 26 changes again and the elevator doors 26 close. Subsequently, the elevator car 5 travels to a next target floor 37 such as the fifth floor. From associated elevator usage information and elevator travel information, it may be inferred that a probability 39 that a car call device 19 indicating the fifth floor has been pressed may be assumed to be for example 50%. Furthermore, it may be assumed that an “up” button of a hall call device 23 on the third floor was pressed with a probability 39 of for example 83%. Lastly, it may alternatively be assumed that a button of a hall call device 23 on the fifth floor was pressed with a probability of 33%.

[0074] In a final step, it is observed that the elevator doors 26 open again for 3 seconds, a car load is decreased to 0% and the light curtain is triggered. From this elevator usage information and elevator travel information, it may be finally inferred that the car call device 23 on the fifth floor was actuated with a probability of 100%, the “up” button of the hall call device 23 on the third floor was actuated with a probability of 100% and the hall call device 23 on the fifth floor was actuated with a probability of 0%, i.e. was not actuated.

[0075] Accordingly, a health status of hall call devices 23 and/or of car call devices 19 may be inferred as a degree of probability 39 for each trip initiated.

[0076] Trips initiated without an opening of elevator doors 26 may be classified as probably being initiated by hall calls.

[0077] Door open times may be used to support a call type inference. For example, a door open time of five seconds may represent hall calls or may at least be more probable for hall calls whereas a door open time of three seconds may represent car calls. These times may be learned for example in a preceding learning procedure.

[0078] Subsequent trips initiated following an increase in elevator car load may be inferred to be car calls and would increase a probability of the initial trip being triggered by a hall call.

[0079] A direction of travel of a subsequent trip may be used to infer the direction of a hall call.

[0080] Trips with no door opening either at a start or an end of the trip are typically parking calls and may be ignored.

[0081] Embodiments of the proposed method and the monitoring device implementing such method may allow inferring the health status of call devices 20 in an elevator arrangement 1 with a reduced number of sensors.

[0082] Finally, it should be noted that the term “comprising” does not exclude other elements or steps and the “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined.

[0083] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.