How to operate an elevator

Abstract

To early suppress excessive rope oscillation to improve elevator riding comfort in a rope oscillation situation.SOLUTION: In a method for operating an elevator (10) installed in connection with a building, in particular, an elevator for a high rise building, expected rope oscillation is monitored by use of building acceleration data obtained by a sensor (28) to calculate building oscillation, rope oscillation is estimated on the basis of building oscillation and a position of an elevator car, rope oscillation is compared to a threshold to determine excessive rope oscillation, and an operating standard value of the elevator (10) is subtracted to correspond to the determined excessive rope oscillation. In this method, a travel profile of the elevator car (14) is determined by an elevator control device (26), a position of the elevator car is predicted (32) on the basis of the travel profile, and estimated rope oscillation is calculated (36) on the basis of the predicted position of the elevator car and the building acceleration data. Thus, excessive rope oscillation, that may occur in the future, can be early detected during response to elevator call by the allocated elevator car.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for operating elevators installed in relation to buildings, in particular elevators for high-rise buildings. These elevators, particularly those installed in high-rise buildings such as skyscrapers, may be subject to building sway caused by strong winds or earthquake waves. When the building sways, the rope may also sway. The rope sway may become excessive, especially when the natural frequency of the rope coincides with the frequency of the building sway. If the rope sway becomes excessive, it may be dangerous because the rope may collide with the devices in the hoistway. [Background technology]

[0002] In response, elevators are equipped with at least one building sway sensor, such as an acceleration sensor. If a certain amount of building sway is measured, elevator operation is interrupted. This may prevent some dangerous situations from occurring due to excessive rope sway. However, elevator operation may also be interrupted in the presence of potential faults, resulting in unnecessary interruptions of elevator service.

[0003] EP 2733103B1 discloses a method for estimating rope sway based on the current position of a moving elevator car and building acceleration (sway) using a pre-calculated table. Elevator operation is interrupted only when the estimated rope sway exceeds a predefined threshold. This method improves elevator operation since elevator operation is interrupted only in selected situations based on the estimation results. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent No. 2733103B1 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a method for suppressing excessive rope sway at an early stage, thereby improving the ride comfort of an elevator in rope sway conditions. [Means for solving the problem]

[0006] The above mentioned object is achieved by a method according to claim 1 and an elevator according to claim 13. Preferred embodiments of the invention are the subject matter of the corresponding dependent claims and are also described in the present specification.

[0007] In the method for operating an elevator installed in relation to a building, in particular an elevator for a high rise building, according to the invention, the building sway is calculated or predicted by monitoring the expected rope sway using building acceleration data obtained by at least one sensor. The rope sway is estimated based on the building sway and the elevator car position. The estimated rope sway is compared with at least one threshold value to determine an excessive rope sway and the determined excessive rope sway is suppressed by subtracting an elevator operation reference value. According to the invention, a running profile of the elevator car is set by the elevator control device. Based on said running profile, a car position of the elevator car is predicted. The estimated rope sway is thus calculated based on the predicted car position and the building acceleration data, and not based on the current car position as shown in the known method according to the patent document 1. An advantage of the method according to the invention is that the excessive rope sway can be calculated before the elevator car is in a position predicted as the position of the excessive rope sway. This would also allow an elevator car to react before it reaches a critical position that correlates with excessive rope sway, thus improving elevator ride comfort and / or increasing elevator safety in rope sway situations.

[0008] In a preferred embodiment, a virtual model of the elevator is used to calculate rope sway based on the measured building accelerations and the predicted elevator car position. The virtual model of the elevator includes important elevator parameters such as car path, counterweight path, rope length and elevator shaft position in the building. It also includes physical properties such as elevator load, counterweight, weight, damping parameters, etc. Thus, the virtual model can be used to calculate rope sway based on the acceleration sensor data and the predicted car position.

[0009] In a preferred embodiment, this calculation is performed in advance during the installation phase, i.e. before the elevator system is put into operation, using a virtual elevator model. In this case, the virtual elevator is used to calculate rope sway amplification data tables. These data tables are further stored in the rope sway control system. Using the virtual model, it is also possible to preliminarily eliminate problematic situations in a sophisticated way. It would thus be possible to lock the elevator travel in one or more points of the hoistway and / or set a reduced speed operation of the elevator cars in one or more points of the hoistway, even if a building sway situation is determined right from the start. This would also make it possible to predict the passenger transport capacity in rope sway situations.

[0010] In a preferred embodiment of the present invention, the estimation of rope sway utilizes the prediction of elevator car position half a building sway period in advance to estimate the corresponding rope sway situation early, so that excessive rope sway can be dealt with in advance.

[0011] In a preferred embodiment, a prediction of the elevator car position is used to estimate the rope sway before half a building sway period, and a corresponding very early estimation of the rope sway situation is made. In this situation, such a very early rope sway estimation is preferably verified by at least one continuous estimation of the rope sway after the elevator car has traveled. Even if this very early rope sway estimation, for example before half a building sway period, lacks accuracy, there is still time to predict an excessive rope sway situation and to counteract the sway. In this case, the very early rope sway estimation is advantageously verified by a car position prediction calculated half a building sway period before the current building sway period.

[0012] If excessive rope sway is determined, several measures can be taken. The elevator car's motion profile can be modified to avoid undesirable locations in the shaft, or to move through these locations quickly, thereby improving the elevator ride quality. Alternatively, the car can be slowed down and stopped at the nearest possible landing, allowing elevator passengers to exit. Alternatively, if excessive rope sway is determined based on an early estimation, the elevator run could be stopped within the acceptable ride quality range. Alternatively or additionally, active measures against excessive rope sway could be taken, such as, for example, a retractable rope sway limiting device, to limit the effects of or respond to excessive rope sway.

[0013] In a preferred embodiment, if excessive rope sway is determined, the elevator car will be slowed down. This would mean that the elevator will continue to travel towards the original destination but at a reduced speed. This would reduce the car vibration caused by the rope sway. As a result, the elevator ride quality would be improved in rope sway situations.

[0014] According to one embodiment, the elevator controller is configured to activate actuators depending on the comparison of the estimated rope sway with a threshold value, which can dynamically reduce the rope sway by interacting with each rope, for example by pressing rollers against the rope via cylinder / piston actuators to eliminate the rope sway at the actuator location, and the use and effect of the actuators may be taken into account when simulating the elevator rope sway.

[0015] According to one embodiment, the actuator is a retractable rope swing limiter, in particular at least one damper arm. This type of actuator is preferably used in skyscrapers, for example at least 500 meters high.

[0016] In a preferred embodiment of the invention, the actual rope displacement is detected and the rope amplitude from the estimated rope sway is corrected to adapt to the current situation. This allows to match the virtual or estimated prediction with the actual situation and correct the prediction according to the current situation. This is a good way to better match the prediction with the actual situation while monitoring the quality of the prediction.

[0017] The invention also relates to an elevator capable of carrying out the above-mentioned method. The elevator comprises an elevator control device configured to predict a running profile of the elevator car, a building acceleration sensor, and a rope sway estimation unit for calculating an estimated rope sway based on the predicted running profile and predicted elevator position data obtained from a signal sent by the building acceleration sensor. Such an elevator is capable of predicting an excessive rope sway before the elevator car reaches a position where the excessive rope sway occurs. Thus, the building sway or acceleration is measured by the sensor, and furthermore, an operation profile of the elevator from the departure floor to the destination floor is determined by the elevator control device. Then, a prediction of the elevator car position over time is obtained from the operation profile established by the elevator control device. Of course, the operation profile can be established not by the elevator control device itself, but by another module or a cloud server connected thereto, for example.

[0018] Preferably, the rope sway is determined by a simulator or virtual elevator based on measured building accelerations, e.g. building vibrations, and elevator car position predictions obtained from the operation profile. Simulations can be performed during the manufacturing phase and the results of the simulations can be recorded in a table (i.e. beforehand during the installation phase as described above), which is then used for real-time rope sway monitoring. In another embodiment, real-time simulations can be used to monitor the rope sway. If excessive rope sway is determined, the elevator can take safety measures. The elevator of the present invention allows an early determination of undesirable rope sway amplitudes. If the predicted rope sway amplitude exceeds a predefined threshold, the elevator operation can be restricted. Of course, the virtual elevator model does not only include the physical properties of the elevator and the building parameters, but also includes a damping model of the entire elevator system, in particular of the roping. The virtual elevator model therefore includes a damping model that specifies in detail the damping coefficient of the rope. Thus, applying said model to study the predicted elevator car position over time increases the accuracy of the rope sway estimation.

[0019] According to an 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 run on a remote server, which may be communicatively connected to the elevator controller and / or the rope sway estimator. A simulation model of the virtual elevator (e.g., parameters of the simulation model) may be updated / modified using measurements from the one or more sensors mentioned above.

[0020] The simulator or virtual model may be realized remotely from the elevator controller and may be further connected via a network, for example as a remote cloud computer or server that communicates with the elevator controller. This allows the present invention to further improve elevator operation in rope sway situations and further improve elevator safety. By using the present invention, the evaluation process of the rope sway monitor can be improved to minimize the interruption of elevator operation, or alternatively, other methods can be adopted as required. Thus, by using the method or elevator of the present invention, elevator operation and conditions can be improved without compromising elevator safety.

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

[0022] The following terms are used synonymously: excessive rope sway is synonymous with rope sway amplitude above threshold, undesirable rope sway amplitude, and simulator is synonymous with virtual elevator, elevator model simulation computer, and virtual model.

[0023] It will be apparent to those skilled in the art that the above-described embodiments can be combined as appropriate.

[0024] The present invention will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0025] [Figure 1] 2 is a flowchart of the elevator of the present invention. [Diagram 2] FIG. 2 is a method flow diagram of the method of the present invention. [Figure 3a] Or [Figure 3c] FIG. 13 is a diagram illustrating an example of building acceleration and rope swing amplitude. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] FIG. 1 shows an elevator 10 included in a building having an elevator shaft 12. The building is in particular a high-rise building such as a skyscraper, and the elevator shaft 12 is a very long shaft for a high-rise elevator. In the elevator shaft 12, the upper parts of the elevator car 14 and the counterweight 20 are connected via upper suspension ropes 22 running on an upper traction sheave 16. Also, the bottom parts of the elevator car 14 and the counterweight 20 are connected via lower compensation ropes 24 running on a lower compensation sheave 18. The car 14 and the counterweight 20 move via the suspension ropes, which interact with the traction sheave by friction, which is connected to the output shaft of the elevator motor.

[0027] The elevator 10 comprises an elevator controller 26 which controls the elevator motor 16 and thus the movement of the elevator car 14. The elevator 10 also comprises call input means, e.g. destination call panels in the lobby and on each floor for inputting destination floors or travel directions. The elevator controller also comprises a car allocation model which allocates generated calls to elevators according to certain optimization criteria, e.g. passenger waiting time, passenger travel time, total ride time, energy consumption, etc.

[0028] A building acceleration sensor 28 is connected to the building, which measures any acceleration acting on the building, for example due to seismic activity, wind pressure, etc. The elevator controller 26 is connected to a rope swing control system 30, which may be part of the elevator controller 26 or may be located remotely from the controller 26, and thus may be provided in a cloud server.

[0029] The swing control system 30 includes an elevator position prediction module 32. The elevator position prediction module 32 has elevator car running profiles for all possible assignment situations. This allows the module 32 to predict the running profile of the car position over time for the elevator car's run between the starting floor and the final destination floor from the current assignment situation and the current elevator car position and / or trip data. The trip data based on the assignment and the current position / trip of the elevator car are obtained from the elevator controller 26 via input line 33. From the position of the elevator car 14, the lengths of all the different rope segments in the elevator hoistway are determined.

[0030] In a first embodiment, the real time rope sway is calculated using pre-calculated amplified data tables 34. These data tables are pre-calculated using a simulator and stored in the storage of the sway control system 30 or the controller.

[0031] In a second alternative embodiment, the rope sway control system 30 further comprises an elevator system simulator 34. The simulator 34 has all the physical parameters of the elevator roping and the damping parameters associated with the roping. In both the first and second embodiments, the heart of the rope sway control system 30 is a real-time rope sway predictor 36, which obtains predicted car position data from the elevator position predictor 32. The first embodiment uses the data tables described above, whereas the second embodiment uses a simulator to calculate the complete physical data from the simulator 34.

[0032] Through the travel profile established by the elevator position prediction unit 32 and the elevator physical data obtained from the simulator / data table 34, the real-time rope sway calculation unit 36 ​​(together with the data obtained from the acceleration sensor 28) is able to calculate the rope sway that the elevator car will encounter during its entire journey along its path in the elevator shaft 12. The rope sway is then calculated taking into account the predicted car position during the course of the car's journey and the current building sway measured by the sensor 28. If the rope sway occurring along the predicted position of the elevator car exceeds at least one threshold value, this means that an excessive rope sway is expected along the elevator car's journey, usually at a certain position of the elevator car, where the natural sway frequency of the free lengths of the suspension ropes 22 and the compensation ropes 24 is increased by the building sway frequency. In this case, an output signal is returned on the output line 38 to the elevator control unit 26, which can modify or stop the elevator journey itself. In some embodiments, this signal may activate a rope sway limiting device 40, for example a roller that contacts the elevator rope to limit rope sway, which can be retracted once the elevator car has passed the dangerous position.

[0033] Optionally, the elevator further comprises at least one rope displacement sensor 41, which may be an optical sensor, which can validate the estimated rope sway data with the actual rope sway, improving the accuracy of the prediction by validating and adapting the estimated data.

[0034] The rope sway control system 30 and / or all of its components 32, 34, 36 may of course be part of the elevator controller or may be disposed in a separate module connected to the elevator controller 26 by a data connection.

[0035] In short, the method of the present invention and the elevator of the present invention shown in Fig. 1 are able to predict undesirable rope sway conditions early, before they actually occur and before the elevator actually assumes the position in question, so that the elevator control device 26 can take appropriate measures in advance to avoid or respond to such situations.

[0036] FIG. 2 shows a flow chart of a method for monitoring elevator rope sway during car travel. Upon receiving an elevator call and subsequent elevator allocation, the elevator travel is recognized by the rope sway prediction unit 36, which executes the method of FIG. 2, through the elevator position prediction module. The prediction routine starts at step 42 and proceeds to step 44 to update the calculation period. In the embodiment of FIG. 2, the calculation period is selected to match the building sway period, but it could be selected in other ways (e.g., the calculation period can be 1 second to 15 seconds). The building sway period can be a constant set by the installer. In step 46, an operating profile is obtained from the elevator control device to predict the elevator car position at the middle of the building sway period. Furthermore, in step 48, the current signal of the building acceleration detector 28 and the data table 34 are used to calculate the building acceleration valid for the current building sway period. In step 50, it is determined (based on data table 34 in the first embodiment or simulator data 34 in the second embodiment) whether the current rope amplitude is still increasing or has already reached the maximum width.

[0037] If the rope amplitude has increased, proceed to step 52, where the current rope swing amplitude is determined to be increased. The rope swing is calculated in step 52 by a first prediction method using an amplification model (e.g., a data table). Otherwise, the rope swing reduction is calculated in step 54 by a second prediction method using a damping model. The use of the damping model is described below.

[0038] The rope sway decreases logarithmically. In real-time rope amplitude calculation, the calculation time step is the building sway period T building (usually a constant given by the builder), where T rope is the car position z in the shaft car The number of rope vibration cycles in one building vibration cycle, n, is determined by defining the following relationship:

[0039]

number

[0040] In other words, n(z car ) is a function of the elevator car position. The rope segment period T rope The values ​​of are calculated a priori using a simulator for different car positions and different rope segments. These values ​​are stored in an array or storage device in the rope swing system 30 for use in calculating the real-time amplitude. The rope segment period T rope corresponds to the first eigenmode of the rope segment.

[0041] Therefore, the elevator rope segment vibration amplitude x (i.e., the value of the exponential decay envelope) after one building cycle is calculated by the following formula:

[0042]

number

[0043] In equation (2), ζ is a damping coefficient, which may be a predetermined constant that may be selected when calculating data table 34. Alternatively, damping coefficient ζ may be defined as a function of elevator car position and the corresponding rope swing amplitude.

[0044] By using equations (1) and (2), a fast and reliable real-time calculation of the rope sway in a damping situation is possible.

[0045] Both steps 52 and 54 merge into step 56, where the rope sway value corresponding to the middle of the current cycle is updated based on step 52 or step 54. The method then proceeds to decision step 58 to determine whether the updated rope sway value requires protective action. If protective action is not required, the method branches to step 64, which waits until the end of the building sway cycle before following the branch back to step 44. If protective action is required, step 60 verifies any currently active sway protection method, for example by reading the operating status of the rope sway limiting device 40 from the elevator control device 26. A distinction is then made according to the priority of the situation, i.e., a sudden increase in the building sway value that occurs for any reason, for example after an earthquake. If the priority is high, protective action is taken immediately in step 62. These measures may include rerouting the car in one direction or another to avoid the undesirable situation, and / or activating the rope sway limiting device, and / or halting the elevator operation after disembarking passengers at the nearest landing, etc. Then, wait until the end of the building sway cycle and return the spur to step 44.

[0046] If the priority is low, step 60 branches to step 64 to wait until the end of the building rocking cycle before returning to step 44.

[0047] The process ensures that a rational, adaptive response can be provided in advance to any undesirable sway condition, so that appropriate measures can be taken, such as disembarking passengers at an early stage before an undesirable situation occurs.

[0048] 3a to 3c show an example of the function of the rope swing control system 30 shown in FIG.

[0049] In Fig. 3, Fig. 3a shows a very simplified example of predicted car position in a 200-meter-long elevator shaft. Reference numeral 22a denotes a suspension rope between the car 14 and the traction sheave 16, and 22b denotes a suspension rope portion between the traction sheave 16 and the counterweight 20. Accordingly, reference numeral 24a denotes a compensation rope portion between the car 14 and the compensation sheave 18, and 24b denotes a compensation rope portion between the compensation sheave 18 and the counterweight 20. Since the car compensation rope 22a and the counterweight compensation rope 24b are freely stretched over almost the entire length of the shaft, the predicted situation is sensitive to excessive rope sway.

[0050] FIG. 3b shows the current signal of the building acceleration sensor 28 of the building in which the elevator 10 is installed.

[0051] Figure 3c shows the amplitude of the rope sway of the various suspension rope sections 22a, 22b and compensation rope sections 24a, 24b, calculated by the rope sway control system 30 for the predicted car and counterweight positions shown in Figure 3a. The system includes some limit values ​​for the rope sway amplitude, beyond which some action will be taken.

[0052] The minimum amplitude limit is the VAS limit, where VAS stands for "variable speed selection," which means that if the limit is exceeded, the elevator will travel slower than normal as it approaches the terminal.

[0053] The next highest limit is the PES limit, where PES stands for "function selection", and when the estimated rope swing exceeds this limit the elevator will run at reduced speed, i.e. at half speed, not necessarily when approaching the terminal.

[0054] The highest limit, shown only in Fig. 3b, is the PARK limit, beyond which the elevator car is brought to an immediate stop at a safe (non-resonant) floor in extreme swing conditions.

[0055] In this manner, the elevator is well-configured to proactively respond to any building condition that may cause an undesirable rope sway condition, such as an earthquake, high winds, or an object hitting the building.

[0056] The invention is not limited to the above-described embodiments but can be modified within the scope of the claims. [Explanation of symbols]

[0057] 10. Elevator 12 Elevator Shaft 14 Elevator car 16 Traction sheave 18 Compensating sheave 20 Counterweight 22 Hanging Rope 24 Compensating rope 26 Elevator control device 28 Building acceleration (swing) sensor 30 Rope swing control system 32 Elevator position prediction module 33 Input line from elevator controller to rope swing control system 34 Virtual Elevator Model-Simulator 36 Rope swing calculation section 38 Output line from rope swing control system to elevator control device 40 Rope swing limiting device 41 (real time) rope displacement sensor 42~64 Rope Swing Calculation Procedure

Claims

1. 1. A method of operating an elevator installed in relation to a building, comprising: monitoring expected rope sway using building acceleration data obtained by a sensor to calculate building sway, thereby estimating rope sway based on the building sway and an elevator car position, comparing the rope sway to a threshold to determine excessive rope sway, and subtracting an operating reference value for the elevator to respond to the determined excessive rope sway, the method comprising: determining a travel profile of the elevator car by an elevator control device; predicting a position of the elevator car based on the travel profile; and calculating an estimated rope sway based on the predicted car position and the building acceleration data.

2. 2. The method of claim 1, further comprising: using a virtual model of the elevator to calculate the rope sway based on the building acceleration and predicted elevator car position.

3. 3. The method according to claim 1 or 2, characterized in that for the rope sway estimation, a prediction of the elevator car position half a building sway period ago is used to obtain an early estimation of the corresponding rope sway situation.

4. 4. The method according to claim 1, wherein the rope sway estimation comprises using a prediction of the elevator car position more than half a building sway period in advance to obtain a very early estimation of the corresponding rope sway situation.

5. 5. The method of claim 4, further comprising verifying the very early estimate of rope sway by performing at least one subsequent estimate of the rope sway after a run of the elevator car.

6. 6. The method of claim 1, wherein when excessive rope sway is determined, an operating profile of the elevator car is altered to move the car as far as possible away from or through undesirable locations in the shaft.

7. 7. The method of claim 1, further comprising: reducing the speed of the elevator car when excessive rope sway is determined.

8. 8. The method of claim 1, wherein when excessive rope sway is determined, the elevator car is slowed down and stopped at the nearest landing and elevator passengers are allowed to exit.

9. 9. The method of claim 6, 7 or 8, further comprising terminating elevator operation within the acceptable ride comfort range upon determination of excessive rope sway based on early estimation.

10. 10. The method according to claim 1, further comprising the step of: activating an actuator when excessive rope sway is determined to be present, thereby suppressing the excessive rope sway and / or an event resulting therefrom.

11. 11. The method of claim 10, further comprising using a retractable rope sway limiting device as the actuator.

12. 12. A method according to claim 1, characterized in that the actual rope displacement is measured by a rope displacement sensor and the rope amplitude obtained from the estimated rope sway is adjusted to suit the current situation.

13. 13. An elevator adapted to carry out the method of any one of claims 1 to 12, comprising: an elevator controller configured to predict a travel profile of the elevator car; A building acceleration sensor; and a rope sway estimation unit that calculates an estimated rope sway based on the predicted running profile and a signal sent by the building acceleration sensor.

14. An elevator as described in claim 13 configured to carry out the method according to claim 12, wherein the rope displacement sensor is connected to the elevator control device.

15. 15. An elevator according to claim 13 or 14, characterized in that it comprises means communicatively connected to a virtual elevator.

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