EP3196160A1 - Method for controlling a closing operation of an elevator door of an elevator cabin - Google Patents

Abstract

A method is proposed for controlling a closing operation of an elevator door (19) of an elevator car (3), as can be implemented in an elevator installation (1). In the method, an access (21) to the elevator car (3) is monitored by means of a light barrier (29), wherein at least one detector (35) of the light barrier (29) outputs a light barrier signal change upon temporary interruption of the light barrier (29). In addition, a weight of the elevator car (3) is monitored by means of a weight measuring arrangement (17) which outputs a weight signal change when the weight of the elevator car (3) changes. The controlling of the closing operation of the elevator door (19) takes place according to the invention taking into account both the change in the light barrier signal and the weight signal change. In particular, malfunctions of the light barrier (29) can be detected in this way and suitable measures can be initiated. For example, in the event that the weight signal change indicates a change in the weight of the elevator car (3) by more than a predetermined minimum weight at least once, but no light barrier signal change indicating a temporary interruption of the light barrier (29) is detected, an emergency closing mode is activated in that the closing operation is controlled in such a way that a risk potential for a person located in a travel path (27) of the elevator door is reduced in comparison to a normal closing of the elevator door (3), for example by reducing the kinetic energy of the elevator door and / or generating a warning tone during the closing of the elevator door (3).

Description

The present application relates to a method for controlling a closing operation of an elevator door of an elevator car. Furthermore, the application relates to an elevator system designed for carrying out such a method, a computer program product and a machine-readable medium.

Elevator systems regularly have at least one elevator car, which can be moved between vertically spaced stops within a building, for example, to be able to carry people between floors of the building. As a rule, the elevator car has an elevator door which must be closed before the elevator car can be moved. If necessary, additional landing doors are provided in the various floors in order to be able to close an access to an elevator shaft, as long as the elevator car does not stop at a certain floor. In contrast to the elevator door, these floor doors do not necessarily have their own drive, but may optionally be moved passively by an opening or closing elevator door.

For example, to minimize waiting times for passengers of an elevator system or to maximize a conveying capacity of the elevator system, it may be advantageous to close the elevator door as quickly as possible when passengers enter or have left the elevator car. However, to prevent a closing door from hindering or even injuring a passenger, regulations may require that the elevator door be closed only when no person is in or near a travel path of the elevator door.

In order to comply with such regulations, a photocell is regularly provided in an elevator door, with the aid of which it is possible to monitor whether the area of the travel path of the elevator door is free of persons or other obstacles before the elevator door can then be closed. In most cases, the light barrier comprises at least one light source which emits a light beam towards a light detector, the light beam extending within or close to the travel path of the elevator door. An interruption of the light beam, ie an interruption of the light barrier, can thus as Indicate that a person or an obstacle is within the travel path of the elevator door.

The term "light" within the formulation "light barrier" can be interpreted broadly and need not be limited to visible light, but may also include other frequency ranges of the electromagnetic spectrum such as infrared.

In modern elevators, instead of a single light beam, the light barrier may also comprise a multiplicity of light beams which run parallel to each other, for example, at certain maximum distances and which are preferably distributed over an entire area of access to the elevator car, a so-called light curtain, in order to avoid it in particular in that, for example, a child or a dog undergoes an intended single-beam photoelectric sensor and thus is not recognized when the child or dog is in the area of movement of the elevator door.

Typically, photoelectric barriers in an elevator car may be configured such that one or more light sources are configured and arranged such that one or more light beams are directed through the range of motion of the elevator door toward one or more detectors. The detectors can detect whether currently light from the light source hits them or not. In this way it can be recognized when a light beam is temporarily interrupted, for example during the entry of a person into the elevator car or when a person leaves the elevator car. Such a temporary interruption of the light barrier leads to a change in the signal output by the detector of the light barrier, hereinafter also referred to as "light barrier signal change". For example, the detector of the light barrier can emit a signal corresponding to a logical "1" as long as the light barrier is not interrupted and output a signal indicating a logic "0" as soon as the light barrier is interrupted. Accordingly, the temporary interruption of the light barrier results in a change of the light barrier signal from "1" to "0". However, other light barrier signals and thus resulting other Lichtschrankensignaländerungen in temporary interruption of the light barrier are also conceivable.

Conventionally, a closing operation of the elevator door is performed at least in consideration of the light barrier signal change. In other words, an elevator control with the aid of a light barrier permanently monitors access to the elevator car, and closing the elevator door is only permitted if the light barrier is not interrupted and it can therefore be assumed that there is no person or obstacle in the area of movement of the elevator door located.

There may be a need for a method of controlling a closing operation of an elevator door of an elevator car, which enables even safer operation of an elevator system. Furthermore, there may be a need for an elevator installation whose elevator control is designed to carry out such a method. Further, there may be a need for a computer program product having machine readable instructions to cause a programmable elevator controller to perform the method of the invention. Finally, there may be a need for a machine-readable medium on which such a computer program product is stored.

At least one such need can be met by the subject matter of any one of the independent claims of the present application. Advantageous embodiments are defined in the dependent claims and the following description.

According to a first aspect of the invention, a method for controlling a closing operation of an elevator door of an elevator car is proposed which comprises at least the following steps: access to the elevator car is monitored by means of a light barrier, wherein at least one detector of the light barrier outputs a light barrier signal change upon temporary interruption of the light barrier , In addition, a weight of the elevator car is monitored by means of a weight measuring arrangement, wherein the weight measuring arrangement outputs a weight signal change when the weight of the elevator car changes. The closing operation of the elevator door is then controlled not only in response to the light barrier signal change, but in consideration of both the light barrier signal change and the weight signal change.

Possible features and advantages of embodiments of the invention may be considered, inter alia, and without limiting the invention, as being based on the ideas and findings described below.

As explained in the introduction, in the operation of an elevator installation, closing of an elevator door is conventionally carried out only taking into account the change in the light barrier signal. In other words, as soon as it receives a request from a cabin operation panel (COP - Car Operation Panel) or a control panel on a floor (LOP - Landing Operation Panel) to move the elevator car to another floor, an elevator controller will first check by checking determine the current light barrier signal or the current or recently registered light barrier signal change, whether the travel of the elevator door is free or if it is, for example, a person. Only when it is determined that the travel is clear and this condition is stable for a certain period of time, does the elevator controller properly actuate actuators of the elevator door to close the elevator door. In such a closing operation, the elevator door can be quickly moved to a closed position, so that the elevator car can then be quickly moved to the desired floor.

However, it can be assumed that a light barrier on an elevator door can lead to malfunctions or failures. In this case, it can no longer reliably be detected by means of the light barrier whether the movement area of the elevator door is currently free.

It is therefore proposed to provide an additional monitoring measure which, with a high probability, enables a correct statement as to whether a person is currently within the range of movement of the elevator door or not. As such additional measure, it is proposed to continuously monitor the weight of the elevator car by means of a weight measuring arrangement. It is assumed that a person entering the elevator car or a person leaving the elevator car leads to a sudden change in weight of the elevator car, which can be detected by the weight measuring device. Since the person entering or leaving the elevator car regularly through the access to the elevator car and thus must move through the range of motion of the elevator door, such a sudden weight change can provide at least a supplementary indication that the travel path of the elevator door is currently not free.

It is therefore proposed to control the closing operation of the elevator door taking into account both the light barrier signal change and the weight signal change. In other words, before an elevator control causes closure of the elevator door or during this closing of the elevator door, it is both possible to monitor whether the signal output by the photocell changes or has already occurred shortly before and thus indicates that the light barrier is currently interrupted and thus the travel path is blocked, and the current weight of the elevator car is monitored and a weight signal change is taken into account as an indication that a person is currently entering or leaving the elevator car. Additional monitoring of the weight of the elevator car and consideration of a weight signal change in addition to monitoring the light barrier and taking into account a Lichtschrankensignaländerung can thus make the closing operation of the elevator door even safer, since it can provide a supplementary plausibility feature in addition to the function of the light barrier to detect whether the range of movement of the elevator door is currently free.

While in the case of a correct function of the light barrier it can generally be detected with sufficient certainty whether the travel path of the elevator door is currently free, the proposed additional monitoring of the weight of the elevator car may be advantageous, in particular in the event of a malfunction of the light barrier. Such a malfunction can be expressed in different ways. On the one hand, the light barrier can fail completely and thus no longer supply any light barrier signal. Such a complete failure of the light barrier can be detected relatively easily. Alternatively, for example, the detector of the light barrier may be so defective that a signal is always output that indicates an uninterrupted light barrier. In this case, for example, the elevator control receives permanently from the light barrier the signal that the light beam is not interrupted and thus the travel path of the elevator door would be free, which, however, may currently not correspond to reality.

Even with a failure or defect of the light barrier, passenger safety must be ensured. Regulations such as the European standard EN81-20 can therefore stipulate that in the event of a failure or a defect of the light barrier, a closing of the elevator door must be modified in such a way that the closing elevator door does not damage a person who is undetected in the travel path of the elevator door can. For this purpose, the said European standard stipulates, for example, that in such a case the elevator door may move at a maximum with a kinetic energy of 4 J and that at the same time a warning tone ("Buzzer") must be output during the closing of the elevator door.

However, it has hitherto posed the problem of how reliably a malfunction or a failure of the light barrier can be detected. In particular, it has been found to be difficult to detect when the light barrier permanently emits a light barrier signal due to a malfunction, which corresponds to an uninterrupted light barrier.

At this point, the possibility provided according to the invention to monitor the weight of the elevator car and also to take into account a weight signal change when controlling a closing operation can be used particularly advantageously. Although recognizing the weight signal change alone is not regarded as a sufficiently reliable indicator for detecting whether the travel path of the elevator door is currently free and thus the elevator door may be quickly closed in its normal mode. However, monitoring the weight of the elevator car and taking into account the weight signal change correlated therewith can optionally be used to detect a malfunction or a defect of the light barrier and then to be able to take appropriate measures to not endanger the elevator door in an emergency closing mode in a passenger To be able to close way and / or issue a warning tone, so that the elevator system can continue to operate despite limited light barrier at least limited.

According to one embodiment, it is therefore proposed, for a case in which the weight signal change indicates a change in the weight of the elevator car by more than a predetermined minimum weight at least once, but no light barrier signal change indicating a temporary interruption of the light barrier is detected in a timely manner. an emergency closing mode is activated. In this emergency closing mode, the closing operation is then controlled such that the elevator door is displaced so as to reduce a risk potential for a person located in the travel path of the elevator door in comparison to a normal closing of the elevator door.

In other words, the weight of the elevator car can be monitored permanently or at regular intervals. If a weight signal change is registered and this indicates that the weight of the elevator car has changed by more than a predetermined minimum weight, it can be assumed that, for example, a person has entered or left the elevator car. The minimum weight may correspond to the weight of a person, especially a light person such as a child, and be 20 kg, for example. The predetermined minimum weight, however, may also be higher, for example, depending on a measuring accuracy of the weight measuring arrangement, for example 40 kg or 70 kg, or less, for example 5 kg or 10 kg.

When entering or leaving the elevator car, the person must regularly cross the light barrier. However, if the detector of the light barrier or the light curtain does not promptly issue a corresponding light barrier signal indicating a temporary interruption of the light barrier or a corresponding light barrier signal change, although a weight change of the elevator car has been detected, it can be assumed that a malfunction has occurred at the light barrier. By "timely" can be understood in this context that in a time frame of for example a few seconds, in particular a time frame of 3s, 2s or only 1s, shortly before and / or after detecting the change in weight of the elevator car, a corresponding Lichtschrankensignaländerung should be detected ,

In such a detection of a malfunction of the light barrier, the closing operation of the elevator door to be performed can be correspondingly modified into an emergency closing mode in which the elevator door is still closed, but this is carried out particularly slowly or carefully so as not to detect any undetectable Persons who could possibly be in the traversing area of the elevator door are at risk.

A discrepancy between a light barrier signal change and a weight signal change can thus indicate a malfunction of the light barrier, whereupon the elevator door may only be closed in the emergency closing mode and must be moved with particular care.

According to one embodiment, in the emergency closing mode, the closing operation may in particular be controlled in such a way that the elevator door is displaced so that a kinetic energy of the elevator door does not exceed a maximum energy of 4 J, for example. Depending on the mass of the elevator door, the elevator door is therefore only moved very slowly when closing, so that a person who is possibly standing in the travel path can move aside in good time.

Additionally or alternatively, according to one embodiment, in the emergency closing mode, the closing operation may be controlled such that a warning sound is output during the closing of the elevator door. The warning sound can be clearly audible to a passenger and warn them of the closing door.

According to one embodiment, the emergency closing mode is activated only when a predeterminable plurality of times the weight signal change indicates a change in the weight of the elevator car by more than the predetermined minimum weight, but no light barrier signal signal indicating a temporary interruption of the light barrier is detected in a timely manner.

In other words, in this embodiment, the emergency closing mode should not be activated directly at a discrepancy occurring for the first time between the Lichtschrankensignaländerung and weight signal change, since such a one-off discrepancy could occur, for example, only due to minor measurement inaccuracies or temporarily limited interference. Instead, it can be provided that only when such a discrepancy occurs several times in succession, a malfunction of the light barrier is assumed and the emergency closing mode is activated. The plurality of times may be, for example, twice, three times, four times, five times, be ten times or more often. In this way, the proposed method can be given a certain tolerance with regard to occurring measurement inaccuracies or short-term disturbances.

It can further be provided that a once activated emergency closing mode need not be maintained permanently by an elevator control until, for example, service personnel repairs the elevator system and resets the elevator control to its normal mode. Instead, provision may be made for the elevator control to monitor again and again during an activated emergency closing mode as to whether the malfunction or defect which led to the activation of the emergency closing mode still exists or whether the emergency closing mode can be deactivated.

For example, according to one embodiment, the emergency closing mode can be deactivated if the weight signal change indicates a change in the weight of the elevator car by more than the predetermined minimum weight at least once and a light barrier signal change indicating a temporary interruption of the light barrier is detected in a timely manner.

In other words, during an activated emergency closing mode, it can be repeatedly monitored whether the discrepancy between the weight signal change and the light barrier signal change which triggers this is still present. Once this is no longer the case and it can be assumed that the light barrier is working correctly again, the emergency closing mode can be deactivated. In this way it can be avoided inter alia that the closing of the elevator door is operated for an unnecessarily long time in the emergency closing mode and thus a complete operation of the elevator system is significantly slowed down.

Similar to the activation of the emergency closing mode, according to one embodiment deactivation of the emergency closing mode may be performed only if a presettable plurality of times the weight signal change indicates a change in the weight of the elevator car by more than the predetermined minimum weight and promptly indicating a temporary interruption of the light barrier Light barrier signal change is detected. In other words, it may be provided that it is not sufficient that the between the weight signal change and the Once the light barrier signal change detected discrepancy disappears once and then immediately the emergency closing mode is disabled, but that for disabling the emergency closing mode at least several times no such discrepancy is detected. As a result, it can be prevented, for example, that a rightly performed activation of the emergency closing mode is prematurely and / or unjustifiably reversed.

In addition to monitoring the weight of the elevator car, further indicators can be detected or monitored, which can give an indication that there is currently a malfunction or a defect in the light barrier and thus the emergency closing mode should be activated.

For example, according to one embodiment, a cabin control panel (COP) may be monitored and recognition of an actuation of the cabin control panel taken into account in a plausibility check of an activation of the emergency closing mode.

This embodiment is based on the consideration that the cabin control panel is operated in particular by persons who have just entered the elevator car. Thus, in the case of a normally functioning light barrier, it is usually just before the control panel is actuated that it will detect an interruption of the light barrier due to an incoming passenger. However, if, for example, above-average frequently an actuation of the cabin control panel is detected without the light barrier has previously issued a light interruption signal change indicating a temporary interruption, this can be interpreted as a supplementary indication that there is a malfunction in the light barrier. This supplemental indication can be used to validate the activation of the emergency closing mode, that is, the emergency closing mode need not be activated solely due to discrepancies between the weight signal change and the light barrier signal change, but may additionally discrepancies between the frequency of operation of the car panel and a previous detection of a Take into account light barrier interruption.

A second aspect of the present invention relates to an elevator system comprising an elevator controller for controlling a closing operation of an elevator door Elevator car, wherein the elevator control is adapted to perform a method according to an embodiment of the first aspect of the invention described above.

The elevator system can be designed in many respects similar or the same as conventional elevator systems. In particular, the elevator installation can have a weight measuring arrangement, which makes it possible to monitor the weight of the elevator car. Such a weight measuring arrangement can, for example, engage a suspension element such as, for example, one or more suspension ropes or carrying belts that hold the elevator car, so that a force measured on the suspension element, at least as long as the elevator car rests, corresponds to the weight of the elevator car. The elevator installation furthermore has a light barrier, in particular a light barrier in the form of a light curtain, on the elevator car. The elevator control of the elevator system can receive signals from both the light barrier and the weight measuring arrangement and evaluate them. In particular, the elevator control should be able to detect discrepancies between light barrier signal changes and weight signal changes and to take these into account when controlling a closing operation of the elevator door. In particular, when detecting excessive discrepancies of the elevator control of the emergency closing mode should be activated and the elevator door can be closed only very carefully.

According to a third aspect of the invention, there is provided a computer program product having machine readable instructions which, when executed on a programmable elevator controller, instruct them to perform a method according to an embodiment of the above first aspect of the invention. The computer program product may include machine-readable instructions in any computer language.

According to a fourth aspect of the invention, a machine-readable medium is proposed on which a computer program product according to the aforementioned third aspect of the invention is stored. The machine-readable medium can thereby store the instructions of the computer program product in various physical ways, for example magnetically or electrically. In particular, the machine-readable medium may be, for example, a CD, a DVD, a flash memory EPROM, etc. Alternatively, the machine-readable medium may also be a server from which the computer program product can be downloaded.

It should be understood that some of the possible features and advantages of the invention are described herein with reference to different embodiments. In particular, features are described in part with respect to an embodiment of the method and in part with respect to an embodiment of the elevator installation. A person skilled in the art will recognize that the features can be suitably combined, transmitted, adapted or replaced in order to arrive at further embodiments of the invention.

Embodiments of the invention will now be described with reference to the accompanying drawings, wherein neither the drawings nor the description are to be construed as limiting the invention.

Fig. 1 shows an elevator system which is adapted to perform a method according to an embodiment of the present invention.

The figure is merely schematic and not to scale.

Fig. 1 shows an elevator system 1, in which a method according to the invention for controlling a closing operation of an elevator door is implemented.

The elevator installation 1 comprises an elevator car 3, which can be displaced vertically within an elevator shaft 5. For this purpose, the elevator car 3 is held by a support means 7 such as one or more ropes or straps. By means of the support means 7, the elevator car 3 can be moved within the elevator shaft 5. For this purpose, the support means 7 can be displaced, for example, by means of a drive motor driving a traction sheave. Optionally, a counterweight is also attached to the support means 7, which counterweight is moved to the elevator car 3. For clarity, neither the engine nor the counterweight are shown in the figure.

Furthermore, the suspension of the elevator car 3 to the support means 7 and the attachment of the support means 7 to stationary structures of the elevator shaft 5 is shown only simplified. In the example shown, for example, one end 9 of the suspension element 7 is fastened via a fastening device 11 to a ceiling 13 of the elevator shaft 5. The support means 7 then extends around a deflection roller 15 held on the elevator car 3 and in this way holds the elevator car 3.

However, the suspension element 7 may also hold the elevator car 3 in a different manner and be fastened in a different manner to stationary structures of the elevator shaft 5. For example, one end of the support means 7 may be fixedly secured to the elevator car 3, whereas an attachment to the ceiling 13 of the elevator shaft 5 may be effected via a deflection roller mounted thereon.

While the specific embodiment of the suspension of the elevator car 3 is not essential to the present invention, it can be considered an essential feature for a possible embodiment of a method according to the invention that there is a possibility of being able to monitor the current weight of the elevator car 3. In general, a weight measuring arrangement designed in any desired way can generally be provided for this purpose.

However, it is advisable, for monitoring the weight of the elevator car 3, to have a weight measuring arrangement interact with the suspension means 3 holding the elevator car 3. In the embodiment shown in the figure, the weight measuring assembly 17 is integrated into the fastening device 11 and acts on this together with the support means 7. For example, the weight measuring arrangement 17 can measure a weight-dependent change in length with the aid of piezo elements, in order to be able to determine therefrom the weight of the elevator car 3 currently acting on the fastening device 11.

However, the weight measuring arrangement 17 can also be designed in another way. For example, sensors and / or strain gauges may be provided between the fastener 11 and the support means 7 to measure weight forces to be transmitted. Alternatively, sensors and / or strain gauges can be provided directly integrated on or in the suspension element 7.

A further possibility for measuring the weight of the elevator car 3 can be realized by measuring a torque to be exerted by a motor driving the support means 7, if the elevator car 3 is held only by the motor without the action of additional brakes, preferably without the elevator car 3 inside to move the elevator shaft 5. A changing weight of the elevator car 3 in this case has a direct effect on the torque to be effected by the motor for holding the elevator car 3 and thus, for example, on the electrical power to be absorbed by the motor.

The elevator car 3 has an elevator door 19, by means of which an access 21 to the elevator car can be closed or released. In the illustrated example, the elevator door 19 has two door leaves 23 which, in the opened state of the elevator door 19, are respectively held in mutually opposite lateral areas of the elevator car 3. In order to close the elevator door 19, the door leaves 23 are displaced in directions represented by arrows 25 along a travel range 27 towards a center of the elevator car and thereby the access 21 to the elevator car 3 is closed.

In order not to jeopardize persons or objects located in the travel area 27 of the elevator door 19 during a closing operation of the elevator door 19, the access 21 to the elevator car, that is to say the travel area 27 of the elevator door 19, is monitored by means of a light barrier 29. In the illustrated example, the light barrier 29 is designed in the form of a light curtain. The light barrier 29 in this case has a plurality of light sources 31. Each of the light sources 31 emits a light beam 33 which is directed so that it traverses the access 21 and thus the traversing area 27 of the elevator door 19, and then on an opposite side of the access 21 to meet there arranged detectors 35.

In the illustrated example, the light beams 33 are emitted horizontally and parallel to each other, wherein a vertical distance between adjacent light beams 33 is only a few centimeters, so that the access 21 is crossed over substantially its entire surface of light rays 33. However, other arrangements of light sources 31 and light beams 33 emitted therefrom may also be implemented, it being preferable to ensure that the light beams 33 of the light barrier 29 traverse the access 21 to the elevator car 3 in such a way that even small persons or, for example, animals entering or leaving the elevator car 3 pass through at least one of the light beams 33 and temporarily interrupt it.

On a side opposite the light sources 31 side of the access 21 a plurality of detectors 35 are arranged, each of which can detect an impact of one of the light beams 33. By means of these detectors 35 can thus be detected when the light barrier 29 is temporarily interrupted, for example when a person enters or leaves the elevator car 3. The detectors 35 emit a light barrier signal as long as each of the light beams 33 strikes a respective detector 35 associated therewith. As soon as at least one of the light beams 33 is temporarily interrupted, this light barrier signal changes.

The light barrier signal or the light barrier signal change can be forwarded by the light barrier 29, for example, via a line 37 to an elevator control 39. However, the light barrier signal or the Lichtschrankensignaländerung can also be transferred to the elevator control 39 in other ways, for example wirelessly. Due to a change in the light barrier signal, the elevator control 39 can thus detect whether the movement area 27 of the elevator door 19 is currently free or whether, for example, a passenger interrupting the light barrier 29 is staying there. If it is detected that the travel area 27 is free, the elevator control 39 can activate the elevator door 19 to close, for example by a signal transmission through a line 38.

A closing operation of the elevator door 19 is thus carried out by the elevator control 39 taking into account the light barrier signal change indicated by the light barrier 29.

In addition to such a conventional light barrier-based monitoring of the access 21 to the elevator car 3, it is provided in the elevator installation 1 proposed herein to additionally carry out a control of the closing operation of the elevator door 19, taking into account a weight signal change. The weight signal correlates with a weight measured by the weight measuring arrangement 17 Elevator Cab 3. If the weight of the elevator car 3 changes, for example due to an incoming or outgoing passenger, this leads to a change in the weight detected by the weight measuring arrangement 17. A corresponding weight signal change can be transmitted from the weight measuring device 17, for example via a line 41 or, alternatively, in another manner, for example wirelessly, to the elevator control 39.

Already in normal operation of the light barrier 29, the consideration of the weight signal change in controlling the closing operation of the elevator door 19 can advantageously be used to check the plausibility of the Lichtschrankensignaländerung.

However, the consideration of both the light barrier signal change and the change in the weight signal when controlling the closing operation of the elevator door 19 can particularly advantageously take effect when the light barrier 29 is subject to a malfunction. For example, cases may occur in which one or more of the light beams 33 are interrupted, but this is not recognized by the associated detector 35 and the detector 35 continues to output an unaltered light barrier signal. In the case of such a malfunction, it has hitherto scarcely been recognizable to the elevator control 39 that there is a malfunction in the light barrier 29. Since the detectors 35 did not indicate a temporary interruption of the photocell 29, the elevator door was always closed at the highest possible speed. Persons located in the travel area 27 of the elevator door 19 were not recognized and possibly endangered when the elevator door 19 is closed.

By means of the method proposed herein, in controlling the closing operation of the elevator door 19, the presence of a malfunction of the photocell 29 can be detected with high probability and appropriate measures taken to avoid endangerment of passengers. In particular, an emergency closing mode can be activated, in which the closing operation is controlled in such a way that a risk potential for a person located in the travel area 27 of the elevator door 19 is reduced in comparison to a normal closing of the elevator door 19.

For example, during the emergency closing mode, the elevator door 19 can only be moved in such a way that its kinetic energy reaches a maximum energy of For example, does not exceed 4 J, so that a collision of the elevator door 19 with a person at least does not lead to serious injury to the person. In addition, it can be provided that during the emergency closing mode, the closing operation is controlled in such a way that a warning tone is emitted during the closing of the elevator door 19. For this purpose, in the elevator car 3, for example, a loudspeaker 43 or Buzzer be provided, which can be optionally activated by the elevator control 39.

In order to determine whether the emergency control mode should be activated by the elevator control 39, a weight signal provided by the weight measuring arrangement 17 can be monitored continuously or at suitable time intervals for changes occurring. Such weight signal change thus informs about a change in the weight of the elevator car 3. The weight of the elevator car 3 changes, in particular, when a person enters the elevator car 3 or leaves the elevator car 3. In such an entry or leaving the person must regularly traverse the access 21 and thus the traversing area 27 of the elevator door 19. In this case, the person also passes through the light barrier 29. In the event of a malfunction of the light barrier 29, such a crossing is not detected by their detectors 35 and correspondingly the light barrier signal output by the light barrier 29 does not change, that is the light barrier signal change is zero.

By taking into account both the light barrier signal change and the weight signal change when controlling the closing operation of the elevator door 19, the emergency closing mode can be activated as soon as the weight signal change at least once changes the weight of the elevator car 3 by more than a predetermined minimum weight, for example more than the typical weight of an entering or leaving person indicates, but timely no a temporary interruption of the light barrier 29 indicating light barrier signal change is detected.

With such an activation of the emergency closing mode, a certain time tolerance can be implemented if necessary. In other words, the temporary interruption of the light barrier does not necessarily have to occur exactly at the same time as the recognition of the weight signal change, but rather slight temporal changes can occur Delays between these two signal changes can be tolerated. Such time delays may, for example, be in the range of less than 2 s or preferably less than 1 s. As a result, inter alia, it can be tolerated that a person initially temporarily interrupts the light barrier, but only briefly delays the weight of the elevator car 3 changes, or vice versa, depending on whether the person enters the elevator car 3 or leaves the elevator car 3.

In order to further increase a tolerance and thus to prevent the emergency closing mode from being unnecessarily activated by, for example, slight disturbances when detecting the light barrier signal change or the weight signal change, it can further be provided that the emergency closing mode is activated only when a preselectable plurality of times one after the other a detected weight signal change is not correlated with a corresponding light barrier signal change.

Furthermore, an activation of the emergency closing mode may also be reversed if, for example, a temporarily occurring malfunction of the light barrier 29 is omitted and the light barrier 29 correctly changes its light barrier signal as soon as one of the light beams 33 is interrupted and thus the light barrier signal change again in a correct manner correlated with the weight signal change. Even if such a deactivation of the emergency closing mode can be waited if necessary, until the weight signal change correlates several times in a row in a correct manner with the Lichtschrankensignaländerung.

In addition, for plausibility of whether to switch to the emergency closing mode or not or whether it should be canceled or not, be taken into account whether and, if so, when a cabin control panel (not shown) is operated. If such an actuation occurs repeatedly or with an above-average frequency without a person having entered the elevator car 3 and this was recognized as a result of the weight change caused thereby, this can be interpreted as a supplementary indication that the light barrier 29 currently has a malfunction and the emergency closing mode should be activated.

Overall, by the method presented here for controlling a closing operation of an elevator door 19 of an elevator car 3 and an elevator system 1 modified to carry out such a method, operation of the elevator installation 1 and in particular a closing operation of the elevator door 19 can be made more secure. In particular, safe operation can also be ensured in the event of a malfunction of the light barrier 29, in that the emergency closing mode can be reliably activated and the elevator installation 1 can continue to be operated without any risk for passengers.

Finally, it should be noted that terms such as "comprising,""comprising," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a multitude. It should also be appreciated that features or steps described with reference to any of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limiting.

LIST OF REFERENCE NUMBERS

1

elevator system

3

car

5

elevator shaft

7

support means

9

End of the suspension element

11

fastening device

13

blanket

15

idler pulley

17

Mass measurement assembly

19

elevator door

21

Access

23

Elevator door

25

movement direction

27

traversing

29

photocell

31

light sources

33

beam of light

35

detectors

37

management

38

management

39

elevator control

41

management

43

speaker

Claims (13)

A method of controlling a closing operation of an elevator door (19) of an elevator car (3), the method comprising: Monitoring an access (21) to the elevator car (3) by means of a light barrier (29), wherein at least one detector (35) of the light barrier (29) outputs a light barrier signal change upon temporary interruption of the light barrier (29); Monitoring a weight of the elevator car (3) by means of a weight measuring arrangement (17) which outputs a weight signal change when the weight of the elevator car (3) changes; Controlling the closing operation of the elevator door (19) taking into account both the light barrier signal change and the weight signal change. The method of claim 1, wherein for a case that at least once the weight signal change indicates a change in the weight of the elevator car (3) by more than a predetermined minimum weight, but timely no a temporary interruption of the light barrier (29) indicating Lichtschrankensignaländerung is determined, an emergency closing mode is activated, in which the closing operation is controlled such that a risk potential for a person located in a travel range (27) of the elevator door person in comparison to a normal closing of the elevator door (3) is reduced. The method of claim 2, wherein in the emergency closing mode, the closing operation is controlled so as to shift the elevator door (19) so that a kinetic energy of the elevator door (19) does not exceed a predetermined maximum energy. A method according to claim 2 or 3, wherein in the emergency closing mode the closing operation is controlled so that a warning sound is emitted during the closing of the elevator door (19). Method according to one of the preceding claims 2 to 4, wherein the Notschließmodus is activated only when a predetermined plurality of times the weight signal change indicates a change in the weight of the elevator car (3) by more than the predetermined minimum weight, but promptly no temporary interruption the photocell (29) indicating light barrier signal change is detected. Method according to one of the preceding claims 2 to 5, wherein the emergency closing mode is deactivated if at least once the weight signal change indicates a change in the weight of the elevator car (3) by more than the predetermined minimum weight and promptly a light barrier signal change indicating a temporary interruption of the light barrier (29) is determined. The method of claim 6, wherein the Notschließmodus is deactivated when a predetermined plurality of times the weight signal change indicates a change in the weight of the elevator car (3) by more than the predetermined minimum weight and promptly a temporary interruption of the light barrier (29) indicating Lichtschrankensignaländerung is determined , Method according to one of the preceding claims 2 to 7, wherein the predetermined minimum weight is 20kg. Method according to one of the preceding claims 2 to 8, wherein the predetermined maximum energy is 4 J. Method according to one of the preceding claims, wherein further a cabin control panel (45) is monitored and a recognition of an operation of the cabin control panel (45) is considered in a plausibility of activating the emergency closing mode. Elevator installation (1) comprising an elevator control (39) for controlling a closing operation of an elevator door (19) of an elevator car (3), the elevator control (39) being designed to carry out a method according to one of claims 1 to 10. A computer program product comprising machine-readable instructions which, when executed on a programmable elevator controller, instruct them to perform a method according to any one of claims 1 to 10. A machine readable medium comprising a computer program product stored thereon according to claim 12.

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