Method for operating an elevator

Abstract

The invention relates to a method for operating an elevator (10), in particular a high-rise elevator, installed in connection with a building (11), in which an expected rope sway is monitored using building acceleration data, which are obtained by means of a sensor (28) to calculate the building sway, and from which a rope sway is estimated based on the building sway and the position of the elevator car, which rope sway is compared with a threshold value to determine an excessive rope sway and to derive operating measures for the elevator in order to counteract the determined excessive rope sway. According to the invention, a series of the following steps are performed: a movement profile for the elevator car (14) is determined by means of an elevator controller (26), the elevator car position is predicted (32) based on the movement profile, and the estimated rope sway is calculated (36) based on the predicted car position and the building acceleration data. This results in an early detection of a possible excessive rope sway occurring in the future during the servicing of an elevator call by the allocated elevator car.

Description

Background Art

[0001] The present invention relates to a method for operating an elevator installed in connection with a building, in particular a high-rise elevator. These elevators, especially in high buildings such as skyscrapers, may be exposed to building sway due to strong winds or earthquake waves. Building sway may cause rope sway. Rope sway may be too large, especially when the natural frequency of the rope matches the frequency of building sway. Excessive rope sway is dangerous because it may cause the rope to hit the hoistway equipment.

[0002] For this reason, elevators are equipped with at least one building sway sensor, such as an acceleration sensor. When a given amount of building sway is measured, elevator operation is interrupted. In this way, any dangerous situations of excessive rope sway can be prevented. However, elevator operation may also be interrupted in potentially harmless situations, resulting in unnecessary interruption of elevator service.

[0003] Publication EP 2 733 103 B1 discloses a solution in which the rope sway is estimated with the aid of pre-calculated tables based on the current position of the running elevator car and the building acceleration (vibration). The elevator operation is interrupted only if the estimated rope sway exceeds a given threshold value. With this solution, based on the estimation result, the elevator operation has to be interrupted only in selected cases, thereby improving the elevator service. Summary of the invention

[0004] The object of the present invention is to provide a method which is able to counteract excessive rope sway at an early stage and to improve elevator ride comfort in the event of rope sway.

[0005] This object is solved with the method according to the invention and with the elevator according to the invention. Preferred embodiments of the invention are the subject matter of the corresponding dependent claims. Preferred embodiments are also described in the description of the application.

[0006] In the method according to the invention for operating an elevator installed in connection with a building, in particular a high-rise elevator, building acceleration data obtained by means of at least one sensor for calculating or predicting the building sway are used to monitor the expected rope sway. Based on the building sway and the position of the elevator car, the rope sway is estimated. The estimated rope sway is compared with at least one threshold value in order to determine an excessive rope sway and to derive operating measures for the elevator in order to counteract the determined excessive rope sway.

[0007] According to the invention, a movement profile of the elevator car is established with the aid of the elevator controller. Based on this movement profile, the car position of the elevator car can be predicted. The estimated rope sway is now calculated based on the predicted car position and building acceleration data instead of based on the current car position as in the known solution from EP 2 733 103 B1. An advantage of the solution of the invention is that it is possible to calculate an excessive rope sway before the elevator car has already assumed a position that is predicted to be a position of excessive rope sway. This again allows countermeasures to be taken before the elevator car reaches a critical position associated with an excessive rope sway. In this way, it is possible to improve the elevator ride comfort and / or to improve the elevator safety in the event of a rope sway.

[0008] In a preferred embodiment of the present invention, a virtual model of the elevator is used to calculate the rope sway based on the measured building acceleration and the predicted elevator car position. The virtual model of the elevator includes key parameters of the elevator, such as the car path, counterweight path, rope length, and the position of the elevator shaft in the building. Further, it includes physical properties, such as elevator load, counterweight, weight, damping parameters, etc. Therefore, by using the virtual model, the rope sway can be calculated based on the acceleration sensor data and the predicted car position.

[0009] In a preferred embodiment, a virtual elevator model is used for the calculations already during the engineering phase (i.e. before the elevator system has been put into operation). In this case, with the aid of the virtual elevator, rope sway amplification data tables are calculated. These data tables are also stored in the rope sway control system. With the aid of the virtual model, it is also possible to already pre-solve problematic situations in a detailed manner. Thus, from the outset when building sway situations are determined, it is possible to lock one or more sections of the hoistway from the elevator travel and / or to set a deceleration operation for the elevator car(s) in one or more sections of the hoistway. As a result, it is also possible to predict the passenger transport capacity in the case of rope sway.

[0010] In a preferred embodiment of the present invention, in order to estimate the rope sway, the elevator car position prediction half a building sway period ahead is used for early estimation of the corresponding rope sway situation. This enables taking countermeasures against excessive rope sway in advance.

[0011] In a preferred embodiment, a prediction of the elevator car position more than half a building sway period in advance is used for the estimation of the rope sway to obtain a very early estimate of the corresponding rope sway situation. In this case, the very early estimate of the rope sway is preferably verified with at least one consecutive rope sway estimation performed after the elevator car operation. This very early rope sway may not be as accurate as for example half a building sway in advance, but it still gives more time to predict an excessive rope sway situation and take countermeasures against it. In this case, it is advantageous to verify the very early estimate of the rope sway with the car position prediction calculated half a building sway period before the current situation.

[0012] If excessive rope sway is determined, several possibilities may occur. The elevator car motion profile may be modified so that the car will avoid undesirable locations in the hoistway or pass through them as quickly as possible. In this way, the elevator ride comfort may be improved. It may also be possible to slow the car down and stop it at the closest possible stop to release the elevator passengers. Alternatively, if excessive rope sway is determined based on an early estimate, it may even be possible to cancel the elevator trip in a manner that potentially impairs ride comfort. Alternatively or additionally, it may be possible to perform active measures on the rope sway, such as operating one or more suitable actuators, such as a retractable rope sway limiting device, to prevent the consequences of or act on the excessive rope sway.

[0013] According to a preferred embodiment, if an excessive rope sway is determined, the elevator car speed is reduced. This can mean that the elevator journey still continues to the original destination, but at a reduced speed. By this measure, it is possible to reduce the car vibrations caused by the rope sway. Thus, the elevator ride comfort can be improved in the case of rope sway.

[0014] According to an embodiment, the elevator controller is configured to operate an actuator depending on the comparison of the estimated rope sway with a threshold value. The actuator can actively reduce the rope sway by interacting with the rope, for example by pushing a roller against the rope via a cylinder / piston actuator to eliminate the rope sway at the actuator. The use of the actuator and the effect of the actuator can also be taken into account when simulating the elevator rope sway.

[0015] According to an embodiment, the actuator is a retractable rope sway limiting device, in particular at least one retractable damping arm.Such an actuator is preferably used in very high buildings, for example in buildings of at least 500 meters in height.

[0016] In a preferred embodiment of the invention, the actual rope displacement is detected and the rope amplitude from the rope sway estimate is corrected to match the current situation. By this measure, the virtual or estimated prediction can be brought into line with the actual situation, allowing the prediction to be corrected according to the actual situation. This is a good means of monitoring the quality of the prediction and bringing the prediction into better line with the actual situation.

[0017] The invention also relates to an elevator capable of performing the above-mentioned method. The elevator comprises an elevator controller configured to predict a movement profile of an elevator car, a building acceleration sensor and a rope sway estimation unit, the rope sway estimation unit being adapted to calculate an estimated rope sway based on predicted elevator position data obtained from the predicted movement profile and a signal from the building acceleration sensor. Such an elevator is capable of predicting an excessive rope sway before the elevator car reaches a position where an excessive rope sway occurs. Thus, the building sway or acceleration is measured using a sensor and, in addition, the movement profile of the elevator from the departure floor to the arrival floor is determined using the elevator controller of the elevator car. The time-dependent elevator car position prediction is then retrieved from the movement profile established by the elevator controller. Of course, it is possible that the movement profile is not established by the elevator controller itself, but by a separate module connected thereto or a cloud server or the like.

[0018] Preferably, the rope sway is determined by means of a simulator or a virtual elevator based on measured building accelerations (e.g. building vibrations) and elevator car position predictions from motion curves. The simulation takes place already during the manufacturing phase and the simulation results can be stored in a table which is then used for real-time rope sway monitoring (i.e., takes place already in the engineering phase, see above). In an alternative embodiment, the real-time simulation can be used for rope sway monitoring. If an excessive rope sway is determined, the elevator can take safety measures. The elevator of the invention allows an earlier determination of an undesirable rope sway amplitude. Then, when the predicted rope sway amplitude exceeds a given threshold, the elevator operation can be restricted. Of course, the virtual elevator model includes not only the physical properties of the elevator and the building parameters, but also a damping model of the entire elevator system, in particular the rope. Therefore, the virtual elevator model includes a damping model which discloses the damping coefficients of the rope in detail. Therefore, the model is adapted to take into account the predicted time-dependent elevator car position, thereby improving the rope sway estimation accuracy.

[0019] According to a preferred embodiment, the elevator may include one or more sensors, such as a rope displacement sensor and / or a car position sensor. The one or more sensors may be connected to an elevator controller. The virtual elevator may be operated in a remote server, which may be communicatively connected to the elevator controller and / or the rope sway estimation unit. The simulation model of the virtual elevator (e.g., parameters of the simulation model) may be updated / corrected with the aid of measurement data from the one or more sensors.

[0020] The simulator or virtual model can be implemented remotely from the elevator controller, even via a network connection, for example as a remote cloud computer or server communicating with the elevator controller. Thus, the present invention provides a further improvement in elevator service and elevator safety in case of rope sway. By means of the present invention, the decision-making process of rope sway monitoring can be advanced so that elevator service interruptions can be minimized and alternative courses of action can be taken instead if necessary. Thus, with the inventive method or elevator, elevator service and availability are improved without compromising elevator safety.

[0021] Typically, the building sway period or natural period of a building is a function of the building height. Typically, for building heights from 100 to 350 meters, the building sway period may be between 2 and 8 seconds.

[0022] The following terms are used as synonyms: Excessive rope sway – rope sway amplitude exceeds a threshold value – Undesirable rope sway amplitude; Simulator – Virtual elevator – Elevator model – Simulation computer - Virtual model;

[0023] It is obvious to the skilled person that the above-mentioned exemplary embodiments can be combined with one another as desired. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the following, the invention is described with the help of the accompanying drawings, in which:

[0025] Figure 1 The flow chart of the elevator of the present invention is shown,

[0026] Figure 2 A method flow chart showing the method of the present invention, and

[0027] Figure 3 Examples of building acceleration and rope sway amplitude are shown. DETAILED DESCRIPTION

[0028] Figure 1An elevator 10 is shown included in a building 11 having an elevator shaft 12. The building 11 is specifically a high-rise building, such as a skyscraper, and accordingly, the elevator shaft 12 is a very long shaft of a high-rise elevator. In the elevator shaft 12, the top of an elevator car 14 and a counterweight 20 are connected via upper suspension ropes 22 running on an upper traction sheave 16. Further, the bottom of the elevator car 14 and the counterweight 20 are connected via lower compensating ropes 24 running on a lower compensating sheave 18. The car 14 and the counterweight 20 move via suspension ropes that are frictionally engaged with the traction sheave, which is connected to the output shaft of the elevator motor.

[0029] The elevator 10 has an elevator controller 26 that controls the elevator motor 16 and thereby controls the movement of the elevator car 14. Further, the elevator 10 includes call input components, such as destination call panels in the lobby and on the floors for inputting destination floors or driving directions. The elevator controller also includes a car allocation model that allocates a given call to an elevator taking into account predetermined optimization criteria (e.g., passenger waiting time, passenger driving time, total ride time, energy consumption, etc.).

[0030] Connected to the building 11 is a building acceleration sensor 28, which measures any acceleration acting on the building, such as caused by seismic activity or wind pressure. The elevator controller 26 is connected to a rope sway control system 30, which can be part of the elevator controller 26 or can be located separately from the elevator controller 26, and thus even in a cloud server.

[0031] The sway control system 30 includes an elevator position prediction module 32. The elevator position prediction module 32 includes motion profiles of the elevator car for all possible allocation situations. Thus, the module 32 can predict the motion profile of the car position over time on its journey between the departure floor and the final destination floor from the current allocation situation and from the current elevator car position and / or movement data. The travel data based on the allocation and the current position / movement of the elevator car are obtained from the elevator controller 26 via input line 34. The position of the elevator car 14 determines the length of all different rope sections in the elevator shaft.

[0032] In the first embodiment, pre-calculated amplified data tables 34 are used for real-time rope sway calculations. These data tables are calculated in advance with the aid of a simulator and stored in the sway control system 30 or in a memory of the controller.

[0033] In the second alternative embodiment, the rope sway control system 30 further includes a simulator 35 of the elevator system. The simulator 35 includes all physical parameters of the elevator of its ropes and all damping parameters related thereto. The core of the rope sway control system 30 of the first and second embodiments is a real-time rope sway calculation unit 36, which obtains the predicted car position data from the elevator position prediction unit 32. In the first embodiment, the data table is used; in the second alternative embodiment, the simulator is used to calculate the complete physical data from the simulator 35.

[0034] The real-time rope sway calculation unit can calculate the rope sway that will occur throughout the journey of the elevator car along its path in the elevator shaft 12, via the movement curve established by the elevator position prediction unit 32 and the physical data / data table of the elevator from the simulator 35, together with the data from the acceleration sensor 28. The rope sway is then calculated taking into account the predicted car position on its way and the current building sway measured by the sensor 28. If the rope sway that will occur along the predicted position of the elevator car exceeds at least one threshold, this means that along the journey of the elevator car, usually at a certain position of the elevator car, an excessive rope sway is expected, where the natural sway frequency of the free length of the suspension rope 22 and the compensation rope 24 increases with the building sway frequency. In this case, a signal is output via the output line 38 back to the elevator controller 26, which is able to modify or cancel the journey of the elevator itself. In some embodiments, the signal can operate a rope sway limiting device 40 (e.g., a roller) to contact the elevator rope to suppress the rope sway, and the rope sway limiting device 40 is retractable after the critical position has been passed by the elevator car.

[0035] Optionally, the elevator further comprises at least one rope displacement sensor 41, which may be an optical sensor. The rope displacement sensor 41 allows to verify the estimated rope sway data with the actual rope sway to verify and adapt the estimated data, which results in better prediction accuracy.

[0036] Of course, the rope sway control system 30 and / or all of its components 32, 34, 36 may be part of the elevator controller or located in a separate module connected to the elevator controller 26 via a data connection.

[0037] In conclusion, Figure 1 The method of the invention and the elevator of the invention shown are able to predict undesirable rope sway conditions at a suitable time before they actually occur, at a suitable time before the elevator actually takes a problematic position. Therefore, the elevator controller 26 is able to take countermeasures in advance at a suitable time to avoid these situations or to act on them.

[0038] Figure 2 A flow chart of a method for monitoring the rope sway of an elevator during car travel is shown. In the case where an elevator call is input and an elevator is subsequently assigned, the elevator journey is performed by executing Figure 2 The method of the rope sway calculation unit 36 ​​is known as the elevator position prediction module. The calculation routine starts at 42 and proceeds to step 44, where the calculation cycle is updated. Figure 2 In the embodiment of the present invention, the calculation period is selected to meet the building sway period, but the calculation period can also be selected differently (the calculation period can be, for example, 1s to 15s). The building sway period can be a constant given by the builder. In step 46, the motion curve from the elevator controller is obtained, and the elevator car position is predicted in the middle of the building sway period. Further, in step 48, the effective building acceleration of the current building sway period is calculated using the current signal of the building acceleration detector 28. In step 50, it is determined based on the data table 34 (in the first embodiment) or the simulator data 34 (in the second embodiment) whether the current rope amplitude is still increasing or has reached a maximum value.

[0039] If the rope amplitude increases, the process branches to step 52, where it is determined that the current rope sway amplitude increases. In step 52, the rope sway is calculated using a first calculation method using an enlarged model (eg, a data table).

[0040] Otherwise, the reduction in rope sway is calculated with a second calculation method using the damping model in step 54. The use of the damping model is explained as follows.

[0041] The reduction of the rope sway occurs logarithmically. In the real-time rope amplitude calculation, the calculation time step is equal to the building sway period T building (usually a constant given by the builder)

[0042] However, the elevator rope segment period T rope is the car position Z in the hoistway car Define the following relationship which gives the number n of rope vibration cycles within one building vibration cycle.

[0043]

[0044] In other words, n(z car ) is a function of the elevator car position. The rope section period T is calculated a priori for different car locations and different rope sections using a simulator. rope These values ​​are stored in an array or in the memory of the rope sway system 30, which is used during real-time amplitude calculations. The rope segment period T used in the calculations rope Corresponds to the first natural mode of the rope section.

[0045] Therefore, the value of the elevator rope segment vibration amplitude x after one building cycle (i.e., the value of the exponential decay envelope) is calculated as

[0046] x(t0+T building )=x(t0)·e -2πnζ (2)

[0048] In (2), ζ is a damping factor, which may be a predefined constant that may be selected when calculating data table 34. Alternatively, damping factor ζ may be defined as a function of the elevator car position and concurrent rope sway amplitude.

[0049] Using equations (1) and (2) allows for fast and reliable real-time calculation of the rope sway under damping conditions.

[0050] Both step 52 and step 54 branch back to step 56, where the rope sway value corresponding to the middle of the current cycle is updated based on step 52 or step 54. Thereafter, the method proceeds to decision step 58, where it is checked whether the updated rope sway value requires protective measures to be taken. If not, the process branches to step 64, where it waits until the end of the building sway cycle, and then branches back to step 44. If yes, in step 60, any current active sway protection method is verified, for example by reading the operating state of the rope sway limiting device 40 from the elevator controller 26. Thereafter, a distinction is made depending on the priority of the situation, that is, depending on any sudden increase in the value of the building sway (for example, after an earthquake). In the case of high priority, protective measures are immediately taken in step 62. These measures include any changes in the car path to avoid undesirable situations and / or activation of the rope sway limiting device and / or stopping of the elevator operation after releasing the passengers (for example, at the nearest stop). Then, the process waits until the end of the building sway cycle and branches back to step 44.

[0051] If the priority is lower, then branching occurs from step 60 to step 64 , where it waits until the building sway period is complete, and then branches back to step 44 .

[0052] This process ensures a reasonable adaptive response to any undesirable swaying condition in advance, allowing appropriate measures to be taken, such as releasing passengers at an early stage, before the undesirable situation is about to occur.

[0053] Figure 3 By way of example, it is schematically shown Figure 1 The function of the rope sway control system 30.

[0054] exist Figure 3 middle, Figure 3 2a shows a very schematic illustration of the predicted car position in an elevator shaft with a length of 200 m. 22a is the suspension rope between the car 14 and the traction sheave 16, while 22b marks the suspension rope section between the traction sheave 16 and the counterweight 20. Thus, 24a marks the compensating rope section between the car 14 and the compensating sheave 18, while 24b marks the compensating rope section between the compensating sheave 18 and the counterweight 20. The predicted situation is sensible for excessive rope sway when the car suspension ropes 22a and the counterweight compensating ropes 24b extend freely along almost the entire shaft length.

[0055] Figure 3 b shows a current signal of a building acceleration sensor 28 for a building in which the elevator 10 is installed.

[0056] Figure 3 c shows the Figure 3 The predicted car and counterweight positions of a, the rope sway amplitudes of the different suspension rope portions 22a, 22b and compensating rope portions 24a, 24b are calculated by the rope sway control system 30. The system includes several limits for rope sway amplitudes which, if exceeded, result in certain actions.

[0057] The lowest amplitude limit is the VAS limit. VAS stands for "Variable Speed ​​Selection," which means that exceeding this limit will cause the elevator to run slower than normal when it approaches a terminal stop.

[0058] The next higher limit is the PES limit, where PES stands for “Performance Selection.” Exceeding this limit due to the estimated rope sway causes the elevator to run at a reduced speed, ie, not only at half speed when approaching a terminal stop.

[0059] Only in Figure 3 The highest limit shown in b is the PARK limit. Exceeding this limit will cause the elevator car to stop immediately at a safe (non-resonant) floor under extreme sway conditions.

[0060] Thus, the elevator is well suited to handle in advance any situations regarding the building that may cause undesirable rope sway conditions (eg, earthquakes, high winds, objects hitting the building, etc.).

[0061] The invention is not limited to the attached embodiments but may be varied within the scope of the following patent claims.

[0062] List of reference numerals:

[0063] 10 Elevator

[0064] 11 Buildings

[0065] 12 Elevator shaft

[0066] 14 Elevator Car

[0067] 16 Traction sheave

[0068] 18 Compensating rope sheave

[0069] 20 Counterweight

[0070] 22 hanging rope

[0071] 24 Compensation rope

[0072] 26 Elevator Controller

[0073] 28 Building acceleration (sway) sensor

[0074] 30 Rope swing control system

[0075] 32 Elevator Position Prediction Module

[0076] 34 Input line from elevator controller to rope sway control system

[0077] 35 Virtual Elevator Model-Simulator

[0078] 36 Rope sway calculation unit

[0079] 38 Output line from rope sway control system to elevator controller

[0080] 40 Rope sway restraint device

[0081] 41 (Real-time) Rope Displacement Sensor

[0082] 42-64 Process steps of the rope sway calculation routine

Claims

1. A method for operating an elevator installed in connection with a building, in which method expected rope sway is monitored using building acceleration data, the building acceleration data is obtained by means of a sensor to calculate the building sway, and the rope sway is estimated therefrom based on the building sway and the position of the elevator car, the rope sway is compared with a threshold value to determine an excessive rope sway and operating measures for the elevator (10) are derived in order to counteract the determined excessive rope sway, characterized in that A series of following steps: - determining a movement profile for the elevator car (14) by means of an elevator controller (26), - based on the movement curve, predicting the position of the elevator car, - calculating an estimated rope sway based on the predicted car position and said building acceleration data.

2. The method according to claim 1, characterized in that A virtual model (35) of the elevator is used to calculate the rope sway based on the building acceleration data and the predicted position of the elevator car.

3. The method according to claim 1 or 2, characterized in that: For the estimation of the rope sway, predicting the position of the elevator car half a building sway period in advance is used to obtain an early estimate of the corresponding rope sway condition.

4. The method according to claim 1 or 2, characterized in that: For the estimation of the rope sway, predicting the position of the elevator car more than half a building sway period in advance is used to obtain a very early estimate of the corresponding rope sway condition.

5. The method according to claim 4, characterized in that The very early estimate of the rope sway is verified using at least one successive estimate of the rope sway performed after the elevator car (14) has been in motion.

6. The method according to claim 1, characterized in that If an excessively large rope sway is determined, the elevator car motion profile is modified so that the car will avoid undesirable locations in the hoistway or pass through them as quickly as possible.

7. The method according to claim 1, characterized in that If excessive rope sway is determined, the elevator car speed is reduced.

8. The method according to claim 1, characterized in that If excessive rope sway is determined, the elevator car (14) is decelerated and stopped at the nearest stop to release the elevator passengers.

9. The method according to claim 6, 7 or 8, characterized in that If excessive rope sway is determined based on early estimates, an elevator trip that potentially compromises ride comfort is cancelled.

10. The method according to claim 1 or 2, characterized in that: If excessive rope sway is determined, the actuator is operated to prevent the excessive rope sway and / or the consequences of excessive rope sway.

11. The method of claim 10, wherein a retractable rope sway limiting device is used as the actuator.

12. The method according to claim 1 or 2, characterized in that: The actual rope displacement is measured with a rope displacement sensor (41) and the rope amplitude from the estimated rope sway is adjusted to match the current situation.

13. The method according to claim 1 or 2, characterized in that: The elevator is a high-rise elevator.

14. An elevator, configured to perform the method according to any one of the preceding claims, the elevator comprising: an elevator controller (26) configured to determine a movement profile of the elevator car (14), Building acceleration sensors, A rope sway estimation unit (32) is used to determine an estimated rope sway based on the predicted movement curve and a signal from the building acceleration sensor (28).

15. The elevator according to claim 14, characterized in that The rope displacement sensor (41) is connected to the elevator controller (26).

16. An elevator according to claim 14 or 15, wherein the elevator comprises means for communicatively connecting to a virtual elevator.

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