Braking force monitoring method and system of elevator traction system and terminal

Abstract

The invention relates to the technical field of elevator traction system control, and discloses an elevator traction system braking force monitoring method and system and a terminal. The braking force monitoring method comprises the following steps that elevator digital twin bodies are constructed; a control program is configured, the elevator digital twinning body is controlled to move, and the movement of the elevator digital twinning body is kept consistent with the movement of the elevator physical entity; configuring an elevator car ascending braking force monitoring model and an elevator car descending braking force monitoring model, wherein the elevator car ascending braking force monitoring model and the elevator car descending braking force monitoring model are both braking force monitoring models for introducing compensation of a steel wire rope, a compensation chain, a traveling cable and a traction wheel; when the elevator car ascends, operating the elevator car ascending braking force monitoring model to obtain an ascending braking force monitoring result; and when the elevator car descends, the elevator car descending braking force monitoring model is operated to obtain a descending braking force monitoring result. According to the invention, the braking performance of the traction system can be monitored more accurately and conveniently.

Description

Technical Field

[0001] The present invention belongs to the technical field of elevator traction system control, and in particular relates to an elevator traction system braking force monitoring method, system and terminal. Background Art

[0002] In modern society, elevators are closely related to people's lives. Once a danger occurs, it is very easy to cause great loss of life and property. In the elevator industry, elevators using traction drive are the most common. This type of elevator uses a traction machine as a drive, one end of the traction rope is connected to the elevator car, bypassing the traction wheel of the top traction motor, and the other end is connected to the elevator counterweight device. When the elevator is running, the traction machine drives the traction wheel to rotate, causing friction with the traction rope, thereby generating traction to drive the elevator car up and down. At the same time, the elevator is also equipped with a safety protection device to ensure that the elevator can be stopped urgently in the event that the traction rope breaks due to excessive tension or the friction between the traction wheel and the traction rope decreases, protecting the lives of passengers.

[0003] With the development and progress of society, the upgrading and iteration of technology has accelerated, and higher requirements have been put forward for the safety monitoring of special equipment: more accurate, more comprehensive and more efficient. In particular, important equipment such as elevators that are related to the safety of people's lives and property are the top priority of technological upgrading. The monitoring and acquisition of real-time data of elevators has always been a difficult problem faced by manufacturers. For the elevator traction system, obtaining its online monitoring data is crucial to improving the safety performance of elevator operation. It can help monitoring or maintenance personnel to find problems with elevator components at the first time and quickly find the root cause of the fault. However, for the elevator traction system, since there is no applicable brake sensor and the virtual sensing technology for vibration force is still in the qualitative measurement stage, the elevator brake faces the problem of being unable to accurately monitor the elevator braking force online.

[0004] In view of this, it is urgent to propose a braking force monitoring method for an elevator traction system. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies in the prior art and propose a method, system, and terminal for monitoring the braking force of an elevator traction system. By constructing an elevator digital twin, an elevator car upward braking force monitoring model and an elevator car downward braking force monitoring model that introduce steel wire ropes, compensation chains, accompanying cables, and traction wheel compensation are configured to ensure that the elevator digital twin operates with correct logic and can transmit data stably, thereby achieving accurate monitoring of the braking force of the elevator traction system.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for monitoring the braking force of an elevator traction system, the method comprising the following steps:

[0008] S10. Build a digital twin of the elevator;

[0009] S11. Configure a control program to control the movement of the elevator digital twin, so that the movement of the elevator digital twin is consistent with the movement of the elevator physical entity;

[0010] S12. Configure the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model. Both the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model are braking force monitoring models that introduce wire ropes, compensation chains, accompanying cables, and traction sheave compensation;

[0011] S13. When the elevator car is moving upward, the elevator car upward braking force monitoring model is run to obtain the upward braking force monitoring result; when the elevator car is moving downward, the elevator car downward braking force monitoring model is run to obtain the downward braking force monitoring result.

[0012] As a possible implementation method, the elevator digital twin is constructed by the following method:

[0013] S100. Construct a three-dimensional model of the elevator;

[0014] S101. Add rigid body properties to the traction system, elevator counterweight, and elevator car in the three-dimensional model, where the rigid body properties include at least mass, moment of inertia, initial translation speed, and initial rotation speed;

[0015] S102. Add kinematic pairs to the traction system, elevator counterweight, and elevator car in the three-dimensional model to standardize the motion behavior of the three-dimensional model; at the same time, add actuators to configure the extreme positions, upper and lower limits of the operating speed, and upper and lower limits of the acceleration of the elevator car and the elevator counterweight in the three-dimensional model to obtain the elevator digital twin.

[0016] As a possible implementation method, the elevator car upward braking force monitoring model is:

[0017]

[0018] Among them, F is the upward braking force, W is the weight of the elevator counterweight, P is the weight of the elevator car, k is the percentage of the actual load to the rated load, Q is the rated load of the elevator, MCC car is the mass of the wire rope on the car side, MTC is the mass of the accompanying cable, v1 is the actual operating speed of the elevator, MWR cw is the mass of the wire rope on the counterweight side, MGP is the mass of the guide pulley on the counterweight side, v2 is the moving speed of the wire rope, J is the moment of inertia of the traction sheave, R is the radius of the traction sheave, g is the acceleration of gravity, K is the traction ratio, and s is the moving distance of the traction sheave when going up.

[0019] As a possible implementation method, the elevator car upward braking force monitoring model is obtained by:

[0020] The upward braking process of the elevator car is analyzed to determine the energy conservation between the friction work between the brake shoe and the traction wheel, the change in gravitational potential energy, and the elevator car and the elevator counterweight. The moment when the brake shoe and the traction wheel are in contact is defined as the start of the formulation. During the braking process from the beginning to the end of braking, the energy changes of the wire rope, compensation chain, accompanying cable, and traction wheel are introduced into the following energy conservation formula:

[0021]

[0022] The elevator car upward braking force monitoring model is obtained by equation transformation.

[0023] As a possible implementation method, the elevator car downward braking force monitoring model is:

[0024]

[0025] Among them, F' is the downward braking force, W is the weight of the elevator counterweight, P is the weight of the elevator car, k is the percentage of the actual load to the rated load, Q is the rated load of the elevator, MCC car is the mass of the wire rope on the car side, MTC is the mass of the accompanying cable, v1 is the actual operating speed of the elevator, MWR cw is the mass of the wire rope on the counterweight side, MGP is the mass of the guide pulley on the counterweight side, v2 is the moving speed of the wire rope, J is the moment of inertia of the traction sheave, R is the radius of the traction sheave, g is the acceleration of gravity, K is the traction ratio, and s′ is the moving distance of the traction sheave when descending.

[0026] As a possible implementation method, the upward braking process of the elevator car is analyzed to determine the mechanical energy conservation between the friction work between the brake shoe and the traction wheel, the change in gravitational potential energy, and the elevator car and the elevator counterweight. The moment when the brake shoe and the traction wheel are in contact is defined as the start of the formulation. During the braking process from the beginning to the end of braking, the energy changes of the wire rope, compensation chain, accompanying cable, and traction wheel are introduced into the following energy conservation formula:

[0027]

[0028] The elevator car downward braking force monitoring model is obtained by equation transformation.

[0029] As a possible implementation method, after the elevator digital twin is built, the braking force monitoring method also includes:

[0030] The operating parameters of the elevator physical entity are added to the traction system, elevator counterweight, and elevator car included in the elevator digital twin, so that signal mapping is established between the elevator digital twin and the elevator physical entity.

[0031] In a second aspect, the present invention provides a braking force monitoring system for an elevator traction system, comprising:

[0032] An elevator digital twin construction unit, used for constructing an elevator digital twin;

[0033] A control program generation unit, used to generate a control program, wherein the control program controls the movement of the elevator digital twin, and the movement of the elevator digital twin is consistent with the movement of the elevator physical entity;

[0034] The braking force monitoring unit is configured with an elevator car upward braking force monitoring model and an elevator car downward braking force monitoring model. Both the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model are braking force monitoring models that introduce wire rope, compensation chain, accompanying cable and traction wheel compensation. When the elevator car is ascending, the elevator car upward braking force monitoring model is run to obtain the upward braking force monitoring result; when the elevator car is descending, the elevator car downward braking force monitoring model is run to obtain the downward braking force monitoring result.

[0035] As a possible implementation method, the elevator digital twin construction unit includes:

[0036] A three-dimensional model building module is used to build a three-dimensional model of the components included in the elevator and assemble them into a complete three-dimensional model;

[0037] Simulation module, the three-dimensional model is imported into the simulation module, and rigid body properties are added to the components included in the three-dimensional model so that the three-dimensional model has the same mass and the same direction of gravity as the physical entity of the elevator; it is also used to add kinematic pairs to the traction system, elevator counterweight, and elevator car included in the three-dimensional model with rigid body properties to standardize the movement behavior of the three-dimensional model; set the extreme positions, upper and lower limits of the operating speed, and upper and lower limits of the acceleration of the elevator car and elevator counterweight in the three-dimensional model to obtain the digital twin of the elevator.

[0038] In a third aspect, the present invention provides a terminal including a processor and a communication interface coupled to the processor, wherein the processor is used to run a computer program or instruction to implement the method for monitoring the braking force of an elevator traction system provided in the first aspect.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] 1. The braking force monitoring method of the elevator traction system provided by the present invention can design and optimize the elevator system in a virtual environment by constructing a digital twin that is exactly the same as the physical entity, avoiding multiple iterations and tests of the physical entity, thereby significantly reducing R&D costs and shortening the R&D cycle.

[0041] 2. The braking force monitoring method of the elevator traction system provided by the present invention proposes an elevator car upward braking force monitoring model and an elevator car downward braking force monitoring model that take into account the energy changes of the wire rope, compensation chain, accompanying cable and traction wheel. Experimental data show that the accuracy of the present invention is greatly improved compared with the existing model, and it is consistent with the real data, and can monitor the braking performance of the traction system more accurately and conveniently.

[0042] 3. The present invention constructs a digital twin of the elevator and performs virtual debugging. The debugging process mainly checks the correctness of the elevator model parameter settings and PLC drive in the NX software. By observing the running status of the PLC program and the operating parameters of the elevator, it is determined whether the elevator system operates according to the set program, whether other errors occur during operation, and whether the operation data is correct. The actual elevator working process is simulated by PLC-based simulation software, and the working environment of the real elevator components is transferred to a virtual environment, which can effectively control the errors that occur in the design stage and the component manufacturing process. This method can effectively overcome the problems of high debugging costs, poor process safety, and long manufacturing time in the debugging process, and can also obtain online monitoring data of elevator operating parameters from a more intuitive perspective. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0044] Figure 1 Flow chart of a method for monitoring the braking force of an elevator traction system in an embodiment of the present invention;

[0045] Figure 2 A schematic diagram of a three-dimensional elevator model constructed in an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of importing the elevator three-dimensional model constructed in SolidWorks software into NX software in STEP format in an embodiment of the present invention;

[0047] Figures 4 to 5 This is a schematic diagram of defining rigid body properties of various components of an elevator in an embodiment of the present invention;

[0048] Figure 6 to Figure 7 A schematic diagram of adding kinematic pairs to various components of an elevator in an embodiment of the present invention;

[0049] Figure 8 It is a schematic diagram of the operation mode of the elevator traction system in an embodiment of the present invention;

[0050] Figures 9 and 10This is a schematic diagram of adding a gear pair and a rack-and-pinion coupling pair to an elevator in an embodiment of the present invention;

[0051] Figure 11 to Figure 12 A schematic diagram of adding position control to an elevator car in an embodiment of the present invention;

[0052] Fig.13 A schematic diagram of writing an elevator control program in TIA Portal software in an embodiment of the present invention;

[0053] Fig.14 A schematic diagram of an elevator control program written in an embodiment of the present invention;

[0054] Fig.15 A schematic diagram of signals for constructing an elevator car and an elevator counterweight in an embodiment of the present invention;

[0055] Figure 16 to Figure 17 A schematic diagram of connecting a signal with a control program and performing debugging in an embodiment of the present invention;

[0056] Fig.18 This is a schematic diagram of the viewer interface when the elevator is running in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0058] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0059] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The following at least one item (items) or similar expressions thereof refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one item (items) of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0060] The embodiments of the present invention aim to propose a method, system and terminal for monitoring the braking force of an elevator traction system. By constructing an elevator digital twin, an elevator car upward braking force monitoring model and an elevator car downward braking force monitoring model that introduce steel wire ropes, compensation chains, accompanying cables and traction wheel compensation are configured to ensure that the elevator digital twin operates with correct logic and can transmit data stably, thereby realizing accurate monitoring of the braking force of the elevator traction system.

[0061] In the first aspect, the present invention provides a method for monitoring the braking force of an elevator traction system. Figure 1 , including the following steps:

[0062] S10. Build a digital twin of the elevator;

[0063] As an example, NX software developed by Siemens is used as the basic platform to construct a digital twin including virtual 3D models, control programs, and virtual hardware.

[0064] As a possible implementation method, the elevator digital twin is constructed by the following method:

[0065] S100. Construct a three-dimensional model of the elevator;

[0066] As an example, SolidWorks software is used to model the various parts of the elevator, and finally assembled into a complete elevator 3D model. The completed elevator 3D model is shown in Figure 2 Import the 3D model constructed in SolidWorks software into NX software in STEP format, see Figure 3 , so that it is easier to add rigid body properties later.

[0067] S101. Add rigid body properties to the traction system, elevator counterweight, and elevator car in the three-dimensional model, where the rigid body properties include at least mass, moment of inertia, initial translation speed, and initial rotation speed;

[0068] For example, the digital twin must have all the same physical properties as the physical entity. Therefore, after the three-dimensional model of the elevator is established, it is necessary to add rigid body properties to the elevator traction system, elevator counterweight, elevator car and other components to ensure that they have the same mass as the physical entity and are subject to the correct direction of gravity. The traction system mainly includes the traction machine, traction wire rope, braking system, guide wheel and return rope wheel; the elevator car is mainly composed of the car body and the car frame, among which the car body includes the car bottom, car wall, car roof, decorative parts, ventilation and lighting devices such as air conditioning and lighting, and control button panels, and the car frame includes columns, beams, inclined rods and ground beams; see Figures 4 to 5 The added rigid body properties include at least mass, moment of inertia, initial translation velocity, and initial rotation velocity.

[0069] S102. Add kinematic pairs to the traction system, elevator counterweight, and elevator car in the three-dimensional model to standardize the motion behavior of the three-dimensional model; at the same time, add actuators to configure the extreme positions, upper and lower limits of the operating speed, and upper and lower limits of the acceleration of the elevator car and the elevator counterweight in the three-dimensional model to obtain the elevator digital twin.

[0070] For example, see Figure 6 to Figure 7 In order to make the movement of each component of the elevator consistent with the physical entity, it is necessary to add kinematic pairs consistent with the physical entity to each key component to standardize its movement behavior. Figure 8 , is the operation mode of the traction system. The elevator car is driven by the car roller, while the elevator counterweight is driven by the counterweight roller to move in the opposite direction. The traction system provides energy to drive the traction wheel to rotate. The friction between the traction wheel and the traction rope provides kinetic energy. The movement form of this part is relatively complex, and a single kinematic pair cannot properly represent its movement mode. Therefore, see Figures 9 and 10 , it is necessary to add gear pairs and gear rack coupling pairs to multiple components respectively. After standardizing the movement mode of each component, it is also necessary to set its movement range, running speed, upper and lower limits of acceleration to ensure that the elevator digital twin is closer to the physical entity. Therefore, it is necessary to add actuators to the key movement components. For example, adding position control to the elevator car Figure 11 to Figure 12 shown.

[0071] S11. Configure a control program to control the movement of the elevator digital twin, so that the movement of the elevator digital twin is consistent with the movement of the elevator physical entity;

[0072] As an example, see Fig.13, the control program is configured using TIA Portal software. In order to meet various requirements of elevator control and deal with faults in the actual operating environment, the elevator control program needs to have the following basic operating logic: build a command management system that receives and processes passenger requests; after receiving multiple requests, arrange commands in the correct time and floor order; elevator car moves; reaches the target floor; opens and closes doors; when there is no command, it must remain on the original floor. In addition to the need to meet the needs of receiving and processing passengers' internal and external calls, current position, and numerical analysis of operating parameters, the following requirements must also be considered during design to ensure that the car operation mode is optimal: minimize operating time; accurately locate the floor where the elevator car is located; maintain a stable speed to improve passenger comfort; and ensure passenger safety by accelerating and decelerating within a safe range. The configured control program is as follows: Fig.14 shown.

[0073] S12. Configure the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model. Both the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model are braking force monitoring models that introduce wire ropes, compensation chains, accompanying cables, and traction sheave compensation;

[0074] As a possible implementation method, the elevator car upward braking force monitoring model is obtained by:

[0075] The upward braking process of the elevator car is analyzed to determine the energy conservation between the friction work between the brake shoe and the traction wheel, the change in gravitational potential energy, and the elevator car and the elevator counterweight. The moment when the brake shoe and the traction wheel are in contact is defined as the start of the formulation. During the braking process from the beginning to the end of braking, the energy changes of the wire rope, compensation chain, accompanying cable, and traction wheel are introduced into the following energy conservation formula:

[0076]

[0077] Transform the equation and put the upward braking force F on the left side of the equation alone, and the elevator car upward braking force monitoring model is obtained as follows:

[0078]

[0079] Among them, F is the upward braking force, W is the weight of the elevator counterweight, P is the weight of the elevator car, k is the percentage of the actual load to the rated load, Q is the rated load of the elevator, MCC car is the mass of the wire rope on the car side, MTC is the mass of the accompanying cable, v1 is the actual operating speed of the elevator, MWR cwis the mass of the wire rope on the counterweight side, MGP is the mass of the guide pulley on the counterweight side, v2 is the moving speed of the wire rope, J is the moment of inertia of the traction sheave, R is the radius of the traction sheave, g is the acceleration of gravity, K is the traction ratio, and s is the moving distance of the traction sheave when going up.

[0080] As a possible implementation method, the downward braking process of the elevator car is analyzed to determine the mechanical energy conservation between the friction work between the brake shoe and the traction wheel, the change in gravitational potential energy, and the elevator car and the elevator counterweight. The moment when the brake shoe and the traction wheel are in contact is defined as the start of the formulation. During the braking process from the beginning to the end of braking, the energy changes of the wire rope, compensation chain, accompanying cable, and traction wheel are introduced into the following energy conservation formula:

[0081]

[0082] The elevator car downward braking force monitoring model is obtained by equation transformation:

[0083]

[0084] Among them, F' is the downward braking force, W is the weight of the elevator counterweight, P is the weight of the elevator car, k is the percentage of the actual load to the rated load, Q is the rated load of the elevator, MCC car is the mass of the wire rope on the car side, MTC is the mass of the accompanying cable, v1 is the actual operating speed of the elevator, MWR cw is the mass of the wire rope on the counterweight side, MGP is the mass of the guide pulley on the counterweight side, v2 is the moving speed of the wire rope, J is the moment of inertia of the traction sheave, R is the radius of the traction sheave, g is the acceleration of gravity, K is the traction ratio, and s′ is the moving distance of the traction sheave when descending.

[0085] S13. When the elevator car is moving upward, the elevator car upward braking force monitoring model is run to obtain the upward braking force monitoring result; when the elevator car is moving downward, the elevator car downward braking force monitoring model is run to obtain the downward braking force monitoring result.

[0086] For example, whether the elevator is going up or down, only the moving direction of the elevator car, counterweight, wire rope and compensation chain changes, and the braking force applied by the brake to the traction wheel does not change, so the friction force does not change either. This is because the working principle of the brake is that the electromagnetic force is lost after the power is cut off, and the spring has no force to oppose it, so it pushes the brake shoe to fit the brake wheel and applies pressure to generate friction. This process is different from the controllable dynamic braking process of common transportation vehicles, but a single static braking process with a stable braking force provided by the spring, and the spring stiffness coefficient, the friction coefficient between the traction wheel and the brake shoe surface, and the compression of the spring when friction occurs will not change in a short time. Therefore, it can be fully considered that the braking force and friction force on the traction wheel during the unloaded upward braking process and the 125% loaded downward braking process of the elevator are equal.

[0087] Next, the advantages of the present invention are explained by specific data calculation. The theoretical values ​​of other motion parameters derived from the braking force are compared with the actual values ​​to verify the accuracy of the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model. Next, the acceleration and deceleration obtained by the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model are compared with the actual values ​​measured by the acceleration sensor, as follows:

[0088] An elevator from Otis China is selected, and the parameters of the elevator are shown in Table 1:

[0089] Table 1 Elevator specific parameters

[0090] Elevator parameters Factory data Traction ratio 2 Number of wire ropes 4 Wire rope diameter (mm) 30×30 Balance coefficient 0.43 Car mass (kg) 1435 Rated speed(m / s) 1.75 Rated load(kg) 1000

[0091] In addition, during the unloaded upward emergency braking process of the elevator, the traction wheel moves 1261mm, the actual running speed of the car is 1.71m / s, the actual running speed of the wire rope is 3.42m / s, the unit length mass of the wire rope, compensation chain and accompanying cable is 3.11kg / m, the mass of the guide pulley on the counterweight side is 100kg, and k = 0. Substituting the above data into the elevator car upward braking force monitoring model, we can get:

[0092]

[0093] Because the braking force of the elevator's no-load upward braking process is equal to that of the 125% load downward braking process,

[0094] That is: F1′=F1=6717.3N

[0095] Since there is only a slip distance between the traction wheel and the brake shoe, the ratio of the traction wheel moving distance to the actual moving distance of the elevator car is exactly the traction ratio, that is: Substituting k=1.25 into the elevator car downward braking force monitoring model, and transforming the equation, moving s′ to the left side of the equation alone, we can get:

[0096]

[0097] Therefore, the distance the elevator car moves is:

[0098]

[0099] The elevator braking process can be regarded as a uniform deceleration process, so the equation can be obtained:

[0100]

[0101] Substituting the data into the above formula, we can get the deceleration of the elevator 125% load downward process as:

[0102]

[0103] According to actual measurement by the acceleration sensor, the deceleration of the elevator under 125% load downward braking is 1.178m / s 2 , and the average deceleration deviation rate obtained by the above calculation is:

[0104] The existing deceleration model that does not consider the energy changes of wire rope, compensation chain, accompanying cable and traction wheel is as follows:

[0105]

[0106] F2′ is the downward braking force. The above data is substituted into the existing model that does not consider the energy changes of the wire rope, compensation chain, accompanying cable and traction wheel, and the resulting deviation rate is 28.7%. It is not difficult to see that the present invention that takes into account the energy changes of the wire rope, compensation chain, accompanying cable and traction wheel has greatly improved the accuracy of the existing model and is in good agreement with the real data. Therefore, the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model proposed in the present invention are of great help in improving the level of online monitoring of the elevator braking force, and can more accurately and conveniently detect the braking performance of the traction system.

[0107] As a possible implementation method, after the elevator digital twin is built, the braking force monitoring method also includes:

[0108] The operating parameters of the elevator physical entity are added to the traction system, elevator counterweight, and elevator car included in the elevator digital twin, so that signal mapping is established between the elevator digital twin and the elevator physical entity.

[0109] As an example, the key to digital twin technology is the ability to control the virtual model and the data association between the elevator digital twin and the physical entity. This requires the establishment of signal mapping so that the data of the two can be transmitted to each other. Therefore, it is necessary to add signals to the moving parts of the elevator, and the added signals need to correspond to the physical entity, that is, they must follow the movement of the parts in the entity. Fig.15 , to build the signals of the elevator car and elevator counterweight. In addition, in the process of building the digital twin of the elevator, it is crucial to achieve real-time communication between the model and the control program, because one of the main functions of the digital twin is to accurately and in real time mirror its corresponding physical entity. This requires the use of the S7-PLCSIM Advanced plug-in under the TIA Portal software to act as a virtual PLC hardware, connect the signals of the elevator model in the NX software with the PLC control program written in the TIAPortal software, realize the data association between the two, and perform software-in-the-loop virtual debugging to ensure that the elevator model and the control program are running with the correct logic. See Figure 16 to Figure 17 , to connect the signal and control program and perform virtual debugging. The elevator PLC control program built with TIA Portal software can simulate the control instructions given by passengers to the elevator in a real environment. On this basis, the advantage of building a digital twin is that using NX software to build an elevator virtual model allows you to open the runtime viewer when the elevator car is moving, and you can arbitrarily choose to obtain online monitoring data of key parameters such as displacement, speed, acceleration, jerk, etc. of the car, and reflect its online change trend in the form of a chart, thereby providing a conditional basis for further research on virtual sensing technology of elevator braking force. See Fig.18 , which is the runtime viewer interface that opens when the elevator car is in motion.

[0110] The present invention constructs a digital twin of the elevator and performs virtual debugging. The debugging process mainly checks the correctness of the elevator model parameter settings and PLC drive in the NX software. By observing the running status of the PLC program and the operating parameters of the elevator, it is determined whether the elevator system operates according to the set program, whether other errors occur during operation, and whether the operation data is correct. The actual elevator working process is simulated by PLC-based simulation software, and the working environment of the real elevator components is transferred to a virtual environment, which can effectively control the errors that occur in the design stage and the component manufacturing process. This method can effectively overcome the problems of high debugging costs, poor process safety, and long manufacturing time in the debugging process, and can also obtain online monitoring data of elevator operating parameters from a more intuitive perspective.

[0111] In a second aspect, the present invention provides a braking force monitoring system for an elevator traction system, comprising:

[0112] An elevator digital twin construction unit, used for constructing an elevator digital twin;

[0113] A control program generation unit, used to generate a control program, the control program controls the movement of the elevator digital twin, and the movement of the elevator digital twin is consistent with the movement of the elevator physical entity;

[0114] The braking force monitoring unit is configured with an elevator car upward braking force monitoring model and an elevator car downward braking force monitoring model. Both the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model are braking force monitoring models that introduce wire rope, compensation chain, accompanying cable and traction wheel compensation. When the elevator car is ascending, the elevator car upward braking force monitoring model is run to obtain the upward braking force monitoring result; when the elevator car is descending, the elevator car downward braking force monitoring model is run to obtain the downward braking force monitoring result.

[0115] As a possible implementation method, the elevator digital twin construction unit includes:

[0116] A three-dimensional model building module is used to build a three-dimensional model of the components included in the elevator and assemble them into a complete three-dimensional model;

[0117] Simulation module, the three-dimensional model is imported into the simulation module, and rigid body properties are added to the components included in the three-dimensional model so that the three-dimensional model has the same mass and the same direction of gravity as the physical entity of the elevator; it is also used to add kinematic pairs to the traction system, elevator counterweight, and elevator car included in the three-dimensional model with rigid body properties to standardize the movement behavior of the three-dimensional model; set the extreme positions, upper and lower limits of the operating speed, and upper and lower limits of the acceleration of the elevator car and elevator counterweight in the three-dimensional model to obtain the digital twin of the elevator.

[0118] In a third aspect, the present invention provides a terminal including a processor and a communication interface coupled to the processor, wherein the processor is used to run a computer program or instruction to implement the braking force monitoring method of the elevator traction system provided in the first aspect.

[0119] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0120] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the present invention and its equivalents.

Claims

1. A method for monitoring the braking force of an elevator traction system, characterized in that: The braking force monitoring method comprises the following steps: S10. Build a digital twin of the elevator; S11. Configure a control program to control the movement of the elevator digital twin, so that the movement of the elevator digital twin is consistent with the movement of the elevator physical entity; S12. Configure an elevator car upward braking force monitoring model and an elevator car downward braking force monitoring model, wherein the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model are braking force monitoring models that introduce wire ropes, compensation chains, accompanying cables, and traction sheave compensation; S13. When the elevator car is moving upward, the elevator car upward braking force monitoring model is run to obtain the upward braking force monitoring result; when the elevator car is moving downward, the elevator car downward braking force monitoring model is run to obtain the downward braking force monitoring result.

2. The method for monitoring the braking force of an elevator traction system according to claim 1, characterized in that: The elevator digital twin is constructed by the following method: S100. Construct a three-dimensional model of the elevator; S101. Add rigid body properties to the traction system, elevator counterweight, and elevator car in the three-dimensional model, wherein the rigid body properties include at least mass, moment of inertia, initial translation speed, and initial rotation speed; S102. Add kinematic pairs to the traction system, elevator counterweight, and elevator car in the three-dimensional model to standardize the motion behavior of the three-dimensional model; at the same time, add actuators to configure the extreme positions, upper and lower limits of the operating speed, and upper and lower limits of the acceleration of the elevator car and the elevator counterweight in the three-dimensional model to obtain the elevator digital twin.

3. The method for monitoring the braking force of an elevator traction system according to claim 1, characterized in that: The elevator car upward braking force monitoring model is: Among them, F is the upward braking force, W is the weight of the elevator counterweight, P is the weight of the elevator car, k is the percentage of the actual load to the rated load, Q is the rated load of the elevator, MCC car is the mass of the wire rope on the car side, MTC is the mass of the accompanying cable, v1 is the actual operating speed of the elevator, MWR cw is the mass of the wire rope on the counterweight side, MGP is the mass of the guide pulley on the counterweight side, v2 is the moving speed of the wire rope, J is the moment of inertia of the traction sheave, R is the radius of the traction sheave, g is the acceleration of gravity, K is the traction ratio, and s is the moving distance of the traction sheave when going up.

4. The method for monitoring the braking force of an elevator traction system according to claim 3, characterized in that: The elevator car upward braking force monitoring model is obtained as follows: The upward braking process of the elevator car is analyzed to determine the energy conservation between the friction work between the brake shoe and the traction wheel, the change in gravitational potential energy, and the elevator car and the elevator counterweight. The moment when the brake shoe and the traction wheel are in contact is defined as the start of the formulation. During the braking process from the beginning to the end of braking, the energy changes of the wire rope, compensation chain, accompanying cable, and traction wheel are introduced into the following energy conservation formula: The elevator car upward braking force monitoring model is obtained by equation transformation.

5. The method for monitoring the braking force of an elevator traction system according to claim 1, characterized in that: The elevator car downward braking force monitoring model is: Among them, F' is the downward braking force, W is the weight of the elevator counterweight, P is the weight of the elevator car, k is the percentage of the actual load to the rated load, Q is the rated load of the elevator, MCC car is the mass of the wire rope on the car side, MTC is the mass of the accompanying cable, v1 is the actual operating speed of the elevator, MWR cw is the mass of the wire rope on the counterweight side, MGP is the mass of the guide pulley on the counterweight side, v2 is the moving speed of the wire rope, J is the moment of inertia of the traction sheave, R is the radius of the traction sheave, g is the acceleration of gravity, K is the traction ratio, and s′ is the moving distance of the traction sheave when descending.

6. The method for monitoring the braking force of an elevator traction system according to claim 5, characterized in that: The downward braking process of the elevator car is analyzed to determine the mechanical energy conservation between the friction work between the brake shoe and the traction wheel, the change in gravitational potential energy, and the elevator car and the elevator counterweight. The moment when the brake shoe and the traction wheel are in contact is defined as the start of the formulation. During the braking process from the beginning to the end of braking, the energy changes of the wire rope, compensation chain, accompanying cable, and traction wheel are introduced into the following energy conservation formula: The elevator car downward braking force monitoring model is obtained by equation transformation.

7. The method for monitoring the braking force of an elevator traction system according to claim 1, characterized in that: After the elevator digital twin is constructed, the braking force monitoring method further includes: The operating parameters of the elevator physical entity are added to the traction system, elevator counterweight, and elevator car included in the elevator digital twin, so that signal mapping is established between the elevator digital twin and the elevator physical entity.

8. A braking force monitoring system for an elevator traction system, characterized in that: include: An elevator digital twin construction unit, used for constructing an elevator digital twin; A control program generating unit, used to generate a control program, wherein the control program controls the movement of the elevator digital twin, and the movement of the elevator digital twin is consistent with the movement of the elevator physical entity; A braking force monitoring unit is configured with an elevator car upward braking force monitoring model and an elevator car downward braking force monitoring model, wherein the elevator car upward braking force monitoring model and the elevator car downward braking force monitoring model are both braking force monitoring models that introduce wire rope, compensation chain, accompanying cable, and traction wheel compensation; When the elevator car is moving upward, the elevator car upward braking force monitoring model is run to obtain the upward braking force monitoring result; When the elevator car is descending, the elevator car downward braking force monitoring model is run to obtain the downward braking force monitoring result.

9. The braking force monitoring system of an elevator traction system according to claim 8, characterized in that: The elevator digital twin construction unit includes: A three-dimensional model building module is used to build a three-dimensional model of the components included in the elevator and assemble them into a complete three-dimensional model; Simulation module, the three-dimensional model is imported into the simulation module, and rigid body properties are added to the components included in the three-dimensional model so that the three-dimensional model has the same mass and the same direction of gravity as the physical entity of the elevator; it is also used to add kinematic pairs to the traction system, elevator counterweight, and elevator car included in the three-dimensional model with rigid body properties to standardize the movement behavior of the three-dimensional model; set the extreme positions, upper and lower limits of the operating speed, and upper and lower limits of the acceleration of the elevator car and elevator counterweight in the three-dimensional model to obtain the digital twin of the elevator.

10. A terminal comprising a processor and a communication interface coupled to the processor, wherein the processor is used to run a computer program or instruction to implement the braking force monitoring method of an elevator traction system according to claims 1 to 7.

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