KR102287889B1 - Method of predicting crack in scaffold and scaffold safety management system using the same - Google Patents

Abstract

Disclosed are a method for detecting stress in a working scaffold and a working scaffold safety management system using the same. The disclosed method for detecting the stress of the working scaffold comprises steps of: acquiring first and second strain information at first and second positions using first and second strain gauges disposed at different first and second positions of the working scaffold, respectively; and obtaining stress information at multiple points of the working scaffold from the first and second strain information, wherein the first and second strain information are strains in the triaxial direction at the first and second positions of the working scaffold, respectively.

Description

Method of predicting crack in scaffold and scaffold safety management system using the same}

The present invention relates to a structure stress detection method and a structure safety management system using the same, and more particularly, to a method for detecting stress in a work scaffold, which is a temporary structure installed for construction or maintenance of a building, and a work scaffold safety management system using the same will be.

Temporary structures installed for construction or maintenance of buildings and used as scaffolds for material transport or workers' passages and work are called working scaffolds or scaffolds.

Since the work scaffold assembly consisting of a number of work scaffolds is installed in a large building, the load of the work scaffold itself is very large, and the material used for construction or maintenance of the facility also has a very large load, so the load increases during work. There is a high risk of collapse due to

Therefore, if the stability of the working scaffold assembly is not secured, psychological stability may be lowered, which may lead to a safety accident. In particular, when a very high load transports the material through the working scaffold assembly, the change in the load transmitted to the working scaffold or the frame supporting the working scaffold is very large. .

JP 2016-130637 A JP 1999-81658 A US 10-2010-0048675 A JP 2014-163866 A

An object to be solved is to provide a method for easily detecting the stress distribution of a working scaffold.

An object to be solved is to provide a method for predicting cracks in the working scaffold from the stress distribution of the working scaffold.

An object to be solved is to provide a working scaffold safety management system that can prevent human accidents by predicting deformation and collapse of the working scaffold assembly in advance.

An object to be solved is to provide a working scaffold and an assembly thereof that can diagnose deformation and collapse in advance.

An object to be solved is to provide a structure stress detection method capable of diagnosing deformation and collapse of a structure in advance, and a structure safety management system using the same.

The technical problem to be solved is not limited to the technical problems as described above, and other technical problems may exist.

In one aspect, a method for detecting stress of a working scaffold includes first and second strains at first and second positions using first and second strain gauges disposed at first and second different positions of the working scaffold. obtaining each information; and obtaining stress information at multiple locations of the working scaffold from the first and second strain information, wherein the first and second strain information are triaxial directions at first and second positions of the working scaffold, respectively. may be a strain of .

In exemplary embodiments, the stress information at multiple locations of the working scaffold may be information of a stress distribution across the working scaffold.

In exemplary embodiments, stress information at multiple locations of the working scaffold may be obtained time-series, and a crack of the working scaffold may be predicted based on the time-series stress information at multiple locations.

In exemplary embodiments, the method for detecting the stress of the working scaffold includes: calculating the accident risk of the working scaffold based on the correlation between time-series stress information and cracks in the working scaffold at multiple locations of the working scaffold; It may further include; determining that there is an accident risk when the rate of change of the accident risk is greater than the reference value.

In exemplary embodiments, the method for detecting the stress of the work scaffold may further include classifying the accident risk by applying machine learning to time-series stress information at multiple locations.

In exemplary embodiments, the method for detecting the stress of the working scaffold may further include, if it is determined that there is an accident risk, notifying the control center or the operator of the accident risk.

In another aspect, the work scaffold safety management system includes a work scaffold assembly to which a plurality of work scaffolds are assembled; and a server for performing safety management for the working scaffold assembly, wherein each working scaffold of the plurality of working scaffolds is disposed at different first and second positions of the plate-shaped plate and the plate, the first of the plate and first and second strain gauges for acquiring the first and second strain information at the second position in time series, and a working scaffold communication unit for transmitting the obtained first and second strain information to the outside, and first and a second strain gauge and a working scaffold control unit for controlling the working scaffold communication unit, wherein the first and second strain information are strain rates in the triaxial direction at the first and second positions of the plate material, and the server includes a plurality of working scaffolds. Based on the first and second strain information for each, time-series stress information at multiple locations of the working scaffold is obtained, and cracks of the working scaffold can be predicted based on the time-series stress information at multiple locations of the working scaffold. .

In example embodiments, the time-series stress information at multiple locations of the work scaffold may be time-series information about a stress distribution across the work scaffold.

In example embodiments, each of the first and second strain gauges may be a three-axis strain gauge that measures strain in different three-axis directions.

In exemplary embodiments, the server calculates the accident risk of the working scaffold based on the correlation between time-series stress information at multiple points of the working scaffold and the crack of the working scaffold, and determines whether there is an accident risk based on the accident risk can do.

In exemplary embodiments, the accident risk α converted from the first and second strains at the first and second positions obtained from the first and second strain gauges is the time-series stress information at multiple points of the working scaffold and If it is less than the accident risk reference value K based on the correlation of cracks in the working scaffold, it can be determined that there is an accident risk.

In exemplary embodiments, the accident risk reference value K based on the correlation between time-series stress information at multiple points of the working scaffold and the crack of the working scaffold is fed back through machine learning to improve the accuracy of determining whether there is an accident risk. can

In exemplary embodiments, it may be determined that there is an accident risk when the stress in the entire area of the working scaffold is reduced to a reference stress or less from a normal value.

In exemplary embodiments, when it is determined that there is an accident risk in at least one of the plurality of work scaffolds, the server outputs an alert to a control center or a site in which the work scaffold assembly is installed. information can be transmitted.

In exemplary embodiments, the server, when it is determined that there is an accident risk in at least one of the plurality of work scaffolds, transmits the accident risk information to the mobile device of the worker located in the work scaffold determined to have an accident risk can

In example embodiments, the mobile device may be a smartphone or tablet PC.

In example embodiments, the mobile device is mounted on work clothes or work helmet, and may include a communication module connected to a communication network, and a speaker or an alarm lamp for outputting an alarm to the operator.

In exemplary embodiments, the work scaffold safety management system may further include a monitoring unit for monitoring the accident risk of the work scaffold assembly.

In exemplary embodiments, the monitoring unit shows an accident risk graph of each of the plurality of working scaffolds, a model diagram of the working scaffold determined to have an accident risk, and an overall model diagram of the working scaffold assembly in which the working scaffold determined to have an accident risk is displayed at least one of them may be displayed.

In example embodiments, the server may be a web server, a cloud server, or a control center server.

In exemplary embodiments, the work scaffold communication unit may include at least one of a mobile communication module, a short-range wireless communication module, and a wired Internet module.

In example embodiments, each working scaffold of the plurality of working scaffolds may transmit the first and second strain information to the server directly through a wireless or wired communication network.

In exemplary embodiments, an assembly communication unit disposed adjacent to the work scaffold assembly to collect first and second strain information of each of the plurality of work scaffolds, the first and second of each of the plurality of work scaffolds being included. The strain information may be transmitted to the server through the assembly communication unit.

In exemplary embodiments, the assembly communication unit may include at least one of a mobile communication module, a short-range wireless communication module, and a wired Internet module.

In another aspect, the working scaffold is a plate-shaped plate material; first and second strain gauges disposed at first and second different positions of the sheet material to obtain first and second strain information at the first and second positions of the sheet material; a working scaffold communication unit for transmitting the first and second strain information obtained from the first and second strain gauges to the outside; and a working scaffold control unit for controlling the first and second strain gauges and the working scaffold communication unit, wherein the first and second strain information may be strains in the triaxial direction at first and second positions of the plate material.

In exemplary embodiments, the plate material may be a plate-like rigid structure.

In exemplary embodiments, the first and second strain gauges may be disposed on a mounting portion of the lower surface of the plate material.

In exemplary embodiments, the mounting portion may be provided in a concave groove in the lower surface of the plate member.

In another aspect, the working scaffold is a plate material including a plate-shaped plate-shaped portion; first and second strain gauges disposed at first and second different positions of the sheet material to obtain first and second strain information at the first and second positions of the sheet material; It may include; an output unit for outputting stress information at a plurality of locations of the plate material based on the first and second strain information: and a controller for controlling the first and second strain gauges and the output unit.

According to the present disclosure, it is possible to predict the crack of the working scaffold through a small number of strain gauges, there is an advantage that can prevent human accidents by predicting the deformation and collapse of the working scaffold assembly in advance based on this.

According to the present disclosure, it is possible to classify the accident risk by applying machine learning to the time-series stress information of the work scaffold, and through this, there is an advantage of more accurately predicting the accident risk.

According to the present disclosure, since it is possible to derive the degree of accident risk of each working scaffold, it is possible to directly notify the operator of the accident risk in advance on the corresponding working scaffold.

According to the present disclosure, it is possible to intuitively inform the manager of the risk of an accident with respect to the work scaffold assembly at the work site.

1 schematically shows a work scaffold safety management system according to an embodiment.
Figure 2 is a rear view of the working scaffold according to an embodiment.
Figure 3 is a side view of the working scaffold of Figure 2;
Figure 4 shows a circuit portion of the working scaffold of Figure 2;
5 shows the relationship of forces in a stable state of the working scaffold from the side of the working scaffold.
6 shows the relationship of forces in a stable state of the working scaffold in a plan view of the working scaffold.
7 shows the relationship of forces in an unstable state of the working scaffold in the plane of the working scaffold.
8 shows the relationship between the first and second strains and the external force in the working scaffold.
9 is a flowchart illustrating an accident risk determination method for a work scaffold according to an embodiment.
10 is a flowchart illustrating a feedback process for the accident risk degree α and the accident risk reference value K.
11 is a graph illustrating an example of accident risk determination in the method for detecting the stress of the working scaffold according to FIG. 9 .
12 is a diagram illustrating generation of an accident risk reference value prediction model through machine learning according to an embodiment.
13 is a diagram for explaining an accident risk reference value K determined through the accident risk reference value prediction model of FIG. 12 .
14 is a graph illustrating accident risk determination according to an embodiment.
15 illustrates an example of a screen monitored by an on-site electronic device according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following drawings, the same reference numerals refer to the same components, and the size of each component in the drawings may be exaggerated for clarity and convenience of description. Meanwhile, the embodiments described below are merely exemplary, and various modifications are possible from these embodiments.

Terms used in the embodiments of the present specification have been selected as currently widely used general terms as possible while considering the functions of the present disclosure, which may vary depending on the intention or precedent of a person skilled in the art, the emergence of new technology, etc. . In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the corresponding embodiment. Therefore, the terms used in the present specification should be defined based on the meaning of the term and the contents of the present disclosure, rather than the name of a simple term.

The singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

In addition, terms such as "unit", "unit", "module", etc. described in the specification mean a unit that processes at least one function or operation, which is implemented in hardware or software, or is a combination of hardware and software. can be implemented.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between the two parts unless 'directly' is used.

As used herein, the expression “configured to (or configured to)” depends on the context, for example, “suitable for”, “having the capacity to” It can be used interchangeably with "," "designed to", "adapted to", "made to", or "capable of". The term “configured (or configured to)” may not necessarily mean only “specifically designed to” in hardware. Instead, in some circumstances, the expression “a system configured to” may mean that the system is “capable of” with other devices or components. For example, the phrase "a controller (or processor) configured (or configured to perform) A, B, and C" may refer to a dedicated controller (or dedicated processor) for performing the operations, or one or more software programs stored in memory. By executing, it may mean a generic-purpose processor (eg, a CPU or an application processor) capable of performing corresponding operations.

1 schematically shows a work scaffold safety management system according to an embodiment.

Referring to FIG. 1 , the working scaffold safety management system includes a working scaffold assembly 100 and a server 200 performing safety management for the working scaffold assembly.

The working scaffold assembly 100 is a structure in which a plurality of working scaffolds 110 are assembled. Each of the working scaffolds 110 has the appearance of a plate-shaped plate (111 in FIG. 2), and is configured to acquire strain information in time-series at two different positions of the plate 111, respectively. Each of the working scaffolds 110 may measure a strain rate in a predetermined time unit (eg, 1 minute unit) using a built-in strain gauge. A more detailed configuration of the working scaffold 110 will be described later.

In one embodiment, the plurality of work scaffolds 110 are fastened and supported by a plurality of frames (eg, pipes, steel materials, etc.) that are connected longitudinally and transversely. The working scaffold assembly 100 is a temporary structure installed for construction or maintenance of a building. As an example, 1 to 2,000 of the working scaffolds 110 may be gathered to form one working scaffold assembly 100 . 1 illustrates a case in which the working scaffolds 110 are installed in a horizontal direction, but is not limited thereto.

In an embodiment, the work scaffold safety management system may further include an assembly communication unit 170 that collects the first and second strain information detected in each of the work scaffold 110 and transmits it to the server 200 through the network. can The assembly communication unit 170 may be disposed adjacent to the working scaffold assembly 100 . Data transmitted from the assembly communication unit 170 to the server 200 may include identification information and first and second strain information of each of the working scaffolds 110 .

The assembly communication unit 170 may include at least one of a mobile communication module, a short-range wireless communication module, and a wired Internet module. The mobile communication module transmits and receives a wireless signal to and from at least one of a base station, an external terminal, and a server on a mobile communication network such as 2G, 3G, 4G, or 5G. The short-range wireless communication module is a module for short-range wireless communication, and includes a wireless network including a wireless LAN and some infrared communication, a wireless personal area network (PAN) including Bluetooth, UWB, Zigbee, etc., and an urban broadband network (Fixed Wireless Access; FWA), including a wireless Metropolitan Area Network (MAN) (Broadband Wireless Access; BWA), and a wireless MAN (Mobile Broadband Wireless Access; MBWA) including Wibro, WiMAX, etc. It may enable at least one wireless communication method of the mobile Internet for The assembly communication unit 170 may be provided with a wired Internet module for wired Internet connection, and may communicate with the server 200 over a wire according to a usage environment. The assembly communication unit 170 performs communication with the server 200 using at least one of a mobile communication module, a short-range wireless communication module, and a wired Internet module, hereinafter, without mentioning a specific communication method, the assembly communication unit 170 is It is said to communicate with the server 200 .

As an example, the assembly communication unit 170 may be a multi-channel WIFI transmitter/receiver capable of communicating with a plurality of work platforms 110 and communicating with the server 200 .

In an embodiment, the first and second strain information detected in each of the up scaffolding 110 may be transmitted to the server 200 through the communication network directly from the working scaffold 110 itself. In this case, the assembly communication unit 170 may be omitted.

In one embodiment, each worker may be carrying an electronic device (for example, a smart phone, a dedicated device installed in work clothes or work helmet) for outputting his or her location information, the assembly communication unit 170 is The individual location information of the worker may be collected and transmitted to the server 200 . Of course, the electronic device of each worker may directly transmit the location information of the Janshin to the server 200 through a wired/wireless communication network.

The server 200 includes a web server 210 that receives strain information (ie, raw data) of each of the working scaffolds 110 , and the working scaffold 110 that is delivered through the web server 210 , respectively. It may include a main processing server 220 that processes the process of predicting cracks in the work scaffold from the strain information, and an on-site electronic device 230 that receives the result data processed by the calculation server 220 and monitors the risk of an accident. there is.

The web server 210 may receive the strain information from the work scaffold assembly 100 through a communication network and store it in the DB. Also, the web server 210 may receive result data processed by the main processing server 220 and provide it to the field electronic device 230 at all times or temporarily. The web server 210 may be, for example, a commercial cloud server provided by Amazon or Google, or a server within a construction company. This web server 210 corresponds to the case of communicating with the work scaffold assembly 100 through the Internet, but is not limited thereto.

The main processing server 220 performs a process of performing stability analysis of the working scaffold assembly in the field from the information transmitted through the web server 210 . The main processing server 220 may be a commercial cloud server or a server within a construction company. The main processing server 220 may be a part of the web server 210 or the same server as the web server 210 . A more detailed description of the process processed by the main processing server 220 will be described later.

In an embodiment, the field electronic device 230 may be a monitoring device monitored by an administrator at a site where the work scaffold assembly 100 is installed. The monitoring device may be part of an integrated computerized system of the construction site. The administrator may receive a notification of the risk of an accident from the web server 210 through the monitoring device, or may access the web server 210 to check monitoring information constantly or temporarily. A more detailed description of monitoring will be provided later.

In an embodiment, the on-site electronic device 230 may be a portable electronic device for workers that can notify the operator of the risk of an accident.

In one embodiment, the portable electronic device for the worker may be, for example, a smartphone, a tablet, or the like. By installing an application that can be connected to the web server 210 on a smartphone or tablet, a notification of the risk of an accident is directly received from the web server 210, or by accessing the web server 210, monitoring information is monitored constantly or temporarily. can be checked

In an embodiment, the portable electronic device for the worker may be installed on the worker's clothes or helmet. The portable electronic device for workers may notify the operator of the risk of an accident through a speaker or a warning light.

In an embodiment, the field electronic device 230 may be installed on the work scaffold 110 . A more detailed configuration for a case in which the on-site electronic device 230 is installed on the work scaffold 110 will be described later.

Next, the working scaffold 110 according to an embodiment, and measuring the stress distribution in the working scaffold 110 will be described.

2 is a rear view of the working scaffold 110 according to an embodiment, and FIG. 3 is a side view of the working scaffold 110 of FIG. 2 .

2 and 3, the working scaffold 110 obtains the first and second strain information in the first and second positions of the plate-shaped plate 111 and the plate 111 in time series, and , the circuit unit 150 configured to transmit the obtained first and second strain information to the outside.

The plate material 111 may be a plate-type rigid structure. The plate 111 may be formed of metal, but is not limited thereto. For example, a portion of the plate material 111 may be formed of a material other than metal. Depending on the installation environment, a portion of the plate material 111 may be convexly protruded or concavely inserted, or may be formed in a curved shape. A coupling part 113 coupled to the frame 119 of the working scaffold assembly 100 is provided on the outer side of the plate 111 . In one embodiment, two coupling portions 113 may be provided on both sides of the plate 111 in the shape of a square flat plate, respectively. The position or number of the coupling portion 113 is not limited.

When the working platform 110 is installed in the horizontal direction, the upper surface of the plate material 111 is scheduled to be placed on the worker's foot or the material is located, and thus the circuit unit 150 may be installed on the back side of the plate material 111. there is. A concave mounting groove 112 is formed on the back surface of the plate 111 for mechanical stability of the circuit unit 150 , and the circuit unit 150 may be mounted in the mounting groove 112 . The mounting groove 112 may be located in the center of the rear surface of the plate 111, but is not limited thereto. A cover (not shown) for protecting the circuit unit 150 may be installed in the mounting groove 112 .

Next, the circuit unit 150 of the working scaffold 110 will be described.

FIG. 4 shows a circuit portion 150 of the working scaffold 110 of FIG. 2 . Referring to FIG. 4 , the circuit unit 150 includes first and second strain gauges 151 and 152 , an A/D converter 153 , a working scaffold communication unit 154 , a controller 155 , and a battery ( 156) may be included. Reference numerals 157 and 158 denote wires connecting the first and second strain gauges 151 and 152 to the A/D converter 153 .

The first and second strain gauges 151 and 152 are disposed at two different positions of the plate material 111 to time-series the first and second strain information at the first and second positions of the plate material 111 . configured to obtain.

The first and second strain gauges 151 and 152 may be a three-axis strain gauge sensor that measures strain in the three-axis direction of the plate material 111 as the strain gauge. For example, the first and second strain gauges 151 and 152 have a structure in which a metallic foil (resistance wire) is supported on a flexible thick plate (eg, a thin plastic film), and It can be used by being attached to the surface (that is, the surface of the mounting groove 112). When the plate 111 is deformed, the foil is deformed to change the electrical resistance of the foil, and the change in resistance may be converted into strain by a gague factor value. The first and second strain gauges 151 and 152 are not limited to a resistance wire method. As another example, an optical method may be employed as the first and second strain gauges 151 and 152 .

In an embodiment, the signals detected by the first and second strain gauges 151 and 152 may be analog signals. Accordingly, the A/D converter 153 converts the analog signals detected by the first and second strain gauges 151 and 152 into digital signals.

In an embodiment, the first and second strain gauges 151 and 152 may themselves include a signal processing module to output a digital signal. In this case, the A/D converter 153 may be omitted.

The work platform communication unit 154 transmits the digital signal converted by the A/D converter 153 to the outside. The work platform communication unit 154 may include at least one of a mobile communication module, a short-range wireless communication module, and a wired Internet module.

The digital signal transmitted from the working scaffold communication unit 154 may include first and second strain information detected by the first and second strain gauges 151 and 152, and identification information of the corresponding working scaffold 110. .

In one embodiment, the working scaffold assembly 100 includes an assembly communication unit 170 , and the working scaffold communication unit 154 transmits data to the assembly communication unit 170 . As described above, the assembly communication unit 170 transmits the data collected from the plurality of work scaffolds 110 to the server 200 .

In one embodiment, the working scaffold communication unit 154 directly transmits the identification information of the working scaffold 110 and the first and second strain information detected in the first and second strain gauges 151 and 152 to the server 200 . may be

The controller 155 may control the overall operation of the circuit unit 150 including the first and second strain gauges 151 and 152, the A/D converter 153 and the working scaffold communication unit 154, and the working scaffold communication unit It can process the data transmitted through (154). For example, the controller 155 adds identification information of the corresponding working scaffold 110 to the first and second strain information converted into a digital signal to cause the working scaffold communication unit 154 to perform a predetermined time interval (eg, 1 minute). interval) can be transmitted to the outside. In addition, the controller 155 is a time tag in which the first and second strain information is detected in the digital signal transmitted from the working scaffold communication unit 154, or the operation status information of the circuit unit 15 of the working scaffold 110 (eg, information on the amount of charge in the battery, information related to malfunctions, etc.) may be included. The controller 155 may perform a function of checking a malfunction of the circuit unit 150 . The controller 155 may be configured to control the operation of the circuit unit 150 by driving an operating system or an application program.

The controller 155 is, for example, a microprocessor, Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Circuits (FPGAs). Gate Arrays) and a central processing unit (Central Processing Unit) may be configured of at least one hardware, but is not limited thereto.

A memory (not shown) may be further provided in the circuit unit 150 . The memory may store various data data for driving and controlling the circuit unit 150 under the control of the controller 155 . Examples of various data data for driving and controlling the circuit unit 150 include identification information of the working scaffold 110, the detection time interval of the first and second strain gauges 151 and 152, information for determining malfunction, etc. can When the controller 155 drives an operating system or an application program, a program or application for this may be stored. Such memories include, for example, a flash memory type, a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), and an electrically erasable programmable read-only (EEPROM). Memory), a programmable read-only memory (PROM), and a magnetic memory may include at least one type of hardware device.

The battery 156 supplies power to drive the circuit unit 150 . The battery 156 may be a rechargeable secondary battery, but is not limited thereto. The circuit unit 150 may be provided with a power terminal (not shown) to which external power can be introduced.

Next, a stable state and an unstable state of the working scaffold 110 will be described.

Figure 5 shows the relationship of force in a stable state of the working scaffold 110 from the side of the working scaffold 110, and Figure 6 shows the relationship of force in a stable state of the working scaffold 110 in the plane of the working scaffold show 5 and 6, in a stable state of the working scaffold 110, the mutually symmetrical tensile force (T) forms a four-point equilibrium with the four places where the coupling parts 1131, 1132, 1133, 1134 are located as the working point. do. Here, the coupling portions 1131 , 1132 , 1133 , and 1134 are pin-jointly coupled to the frame ( 119 in FIG. 3 ), so that the boundary condition can be set to a free end.

7 shows the relationship between the forces in an unstable state of the working scaffold 110 in a plane of the working scaffold.

That the working scaffold 110 is 'stable' may be understood as a state in which an appropriate tensile force is applied to each structural member of the working scaffold 110 . That is, that the working scaffold 110 is 'stable' can be interpreted as meaning that the structural members constituting the working scaffold 110 maintain elastic deformation (restorative force). If the structural member (for example, the plate material 111) of the working scaffold 110 is subjected to plastic deformation (cracking, foreshadowing destruction), the existing tensile force is removed and the force cannot be exerted. . Therefore, it can be estimated that cracks, deformations, warpages, and fractures have occurred in the relevant structural member by tracking the time when the stress is relieved during regular stress measurement.

As an example, a case of destruction of the coupling portion 113 of the working scaffold 110 is as follows. If one coupling part 113 is damaged and the tensile force is lost at the corresponding part, it can be assumed that a kind of negative tension (-T) is applied, and the action position of -T can be known according to the above estimation strategy. That is, the moment the coupling portion 113 is broken, the stress over the entire working scaffold 110 is instantaneously relieved, which can be estimated that a negative tension (-T) is imposed. In addition, stress relief due to cracking is a precursor symptom even before the stress is completely relieved, and it can be considered that negative tension started to operate due to cracking and bending phenomena. Therefore, from the standpoint of judging the stability from the stress distribution, when the action position of the new external force coincides with one of the four bonding sites (when the intersection is located on the line ① or the pointing direction line), the corresponding coupling part 1133 It is possible to suspect bending, cracking, breakage, etc., and it is possible to predict the destruction of the working scaffold 110 of the working scaffold 110 . Therefore, even before an accident caused by the work scaffold 110 has occurred, the operator can move to the work scaffold 110 to perform inspection and maintenance.

As an example, the cases of damage caused by the transport of heavy goods by workers and the cases of damage in the process of dismantling and storage are as follows. In a normal case, an instantaneous stress change occurs in the work scaffold 110 according to the steps of the worker and is repeatedly removed. If the deformation or cracking of the work scaffold 110 is caused by carrying excessive weight materials, θ ₁ , θ ₂ are specified as residual stress behavior and are not restored to 0 (line ②). However, since the magnitude of the measured residual stress is much larger than the nonlinear dynamic stress factor caused by the self-load and environmental reaction factors of the working scaffold 110, structural instability determination is possible. Damage due to impact such as dismantling or falling of the work scaffold 110 may also be understood as the same type.

Next, the stress detection of the working scaffold 110 and a method of determining the accident risk for the working scaffold 110 using the same will be described.

FIG. 8 shows the relationship between the first and second strains and the external force in the working scaffold 110 .

Referring to FIG. 8 , since the working scaffold 110 is coupled to the frame using the coupling part 113 , the working scaffold 110 is subjected to a tensile force through the coupling part 113 . 8 is a case in which the working scaffold 110 has four coupling parts 1131 , 1132 , 1133 , 1134 . _{Tensile force (T 11} , T ₁₂ , T ₂₁ , T ₂₂ ) applied to the four coupling parts 1131 , 1132 , 1133 , 1134 , or the weight of the load or the operator loaded on the working scaffold 110 is the working scaffold 110 . acts as an external force that deforms it.

The external force and the amount of deformation on a thin rectangular plate having a predetermined modulus of elasticity are known as a predetermined differential equation, and conventionally, a stress analysis is performed using a finite element method or the like. However, if you want to apply the existing solution such as the finite element method to the working scaffold 110, it is necessary to measure the amount of deformation at multiple positions of the working scaffold 110, and accordingly, the amount of calculation in the working scaffold 110 itself. Problems arise that increase. Due to this problem, it is difficult to perform low power consumption stress analysis on the work scaffold 110 that requires real-time, long-time stress measurement. Therefore, an estimation strategy to simplify the stress analysis is required. In this embodiment, the stress distribution over the entire area of the working scaffold 110 is calculated from the first and second strain information obtained at two different positions as follows.

From the calculation of the stress distribution as described above, it is possible to not only detect whether each of the working scaffolds 110 is bent, but also analyze the buckling phenomenon of the vertical member of the working scaffold assembly 100 . For example, when the working scaffolds 110 are coupled in a truss structure, in a normal state, the compressive and tensile forces are cross-repeated by the working scaffolds 110 located on both sides of the working scaffolding 110 . When buckling occurs in the vertical member coupling the working scaffold 110 , there is a change in the tensile force (or compressive force) applied to the working scaffold 110 , so the vertical member from the first and second strains detected in the working scaffold 110 . Even the buckling phenomenon (zigzag phenomenon) of

9 is a flowchart illustrating an accident risk determination method for a work scaffold according to an embodiment, FIG. 10 is a flowchart illustrating a feedback process for an accident risk degree α and an accident risk reference value K, and FIG. It is a graph showing an example of accident risk determination in the stress detection method of the working scaffold.

,

을 측정한다(S310).Referring to FIG. 9 , first and second strains using first and second strain gauges 151 and 152 at two spaced apart places of the working scaffold 110 .

,

is measured (S310).

로 표시될 수 있다. 여기서 l은 길이, △l은 길이의 변형량을 나타낸다. 3축 스트레인 게이지는 서로 다른 방향의 3축에 대한 변형률을 계측한다. Strain is a value that quantifies the geometrical deformation of a material caused by stress.

can be displayed as Here, l denotes the length and Δl denotes the amount of deformation of the length. A triaxial strain gage measures strain along three axes in different directions.

,

과 제1 및 제2 스트레인 게이지(151, 152)의 설치 위치에 대한 정보를 기초로, 작업 발판(110)에 대한 응력 정보를 획득한다(S320).Next, the measured first and second strains

,

And on the basis of the information on the installation position of the first and second strain gauges 151 and 152, it acquires stress information for the work scaffold 110 (S320).

The strain in the 3-axis direction measured by the 3-axis strain gauge _{can be transformed into strain components ε x} , ε _y , and γ _xy in the Cartesian coordinate system, and the direction θ of the external force therefrom can be given by the following equation. In the following equation, the direction θ of the external force is based on the position at which the strain is measured.

,

라고 하면, 외력(F)이 위치(x, y)는 제1 위치를 기준으로 변형률

의 방향 θ₁과 제2 위치를 기준으로 변형률

의 방향 θ₂으로부터 결정될 수 있다. 즉, 외력(F)의 위치(x, y)는 제1 위치를 기준으로 θ₁ 방향의 연장선과 제2 위치를 기준으로 θ₂ 방향의 연장선에 만나는 교점으로 결정될 수 있다. 이는 하기의 수학식으로 표현될 수 있다.That is, the first and second strains at the first and second positions obtained from the first and second strain gauges 151 and 152 are

,

If , the external force F is the position (x, y) of the strain with respect to the first position

Strain relative to the direction θ ₁ and the second position of

can be determined from the direction θ _{2 .} That is, the position (x, y) of the external force F may be determined as an intersection point that meets the extension line in the _{θ 1} direction with respect to the first position and the extension line in the θ _{2 direction with respect to the second position.} This can be expressed by the following equation.

과 방향 성분 분석으로 산출된 위치(x, y)를 이용해 제1 위치에서의 제1 모멘트의 크기와 방향을 역산할 수 있으며, 제2 위치에서의 제2 변형률

과 위치(x, y)를 이용해 제2 위치에서의 제2 모멘트의 크기와 방향을 역산할 수 있다. 제1 위치에서의 제1 모멘트와 제2 위치에서의 제2 모멘트와, 위치(x,y)로부터 외력(F)의 크기가 산출된다. 이는 하기의 수학식으로 표현될 수 있다.In addition, since the moment is expressed as the product of the external force and the acting position, the first strain at the first position

The magnitude and direction of the first moment at the first position can be inversely calculated using the position (x, y) calculated by the hyperdirection component analysis, and the second strain at the second position

Using and position (x, y), the magnitude and direction of the second moment at the second position can be inversely calculated. The magnitude of the external force F is calculated from the first moment at the first position, the second moment at the second position, and the position (x,y). This can be expressed by the following equation.

As a result, the magnitude and position of the external force F of the working scaffold 110 can be measured from the first and second strain information obtained at two different positions, and from this, the stress on the entire area of the working scaffold 110 . can be calculated.

Next, based on the stress information on the working scaffold 110, an accident risk α for the working scaffold 110 is derived (S330).

,

로부터 주어지는 함수일 수 있다. 수학적인 기법에 의해서 연산자 β_j = f_cj(P₁ ^*, P₂ ^*, △P) (j=1,2)로 바꾸고, β₁, β₂의 함수로서 사고위험도 α = f_d(β₁, β₂)를 도입한다. 연산자 β_j에서 △P는 P₁ ^*, P₂ ^*의 실측값과 연산값의 차이이다. 도 10에 도시되듯이 P₁ ^*, P₂ ^*, △P를 획득하는 단계(S3201)와 β₁, β₂를 산술하는 단계(S3202)에 피드백을 줌으로써 △P를 소정값 이하가 되도록 하여, 시스템에 대한 신뢰도를 높일 수 있다. In one embodiment, the calculated value P ₁ ^* = f _a calculated from the physical quantity of the working scaffold 110 and the actual measured value P ₂ ^* = f _b obtained by actually measuring the working scaffold 110 are obtained. The calculated value P ₁ ^* may be designed to physically correspond to _{the measured value P 2} ^* that may be measured with respect to the working scaffold 110 . The function f _a of the calculated value P ₁ ^* may be given as a function of a physical quantity (eg, elastic modulus, self-mass, width, width, etc.) of the working scaffold 110 . The function f _b of the measured value P ₂ ^* is the first and second strains measured in the working scaffold 110 .

,

It can be a function given from By mathematical technique, operator β _j = f _cj (P ₁ ^* , P ₂ ^* , ΔP) (j=1,2) is changed, and accident risk α = f _d (β _{1 ) as a function of β 1} , β ₂ , β ₂ ) is introduced. In the operator β _j , ΔP is the difference between the measured and calculated values of _{P 1} ^* and P ₂ ^{* .} As shown in Figure 10, by giving feedback to the step (S3201) of obtaining _{P 1} ^* , P ₂ ^* _{, ΔP and the step (S3202) of arithmetic on β 1} , β ₂ so that ΔP is below a predetermined value, It can increase the reliability of the system.

Next, the accident risk degree α and the accident risk reference value K are compared (S340). The accident risk reference value K is an actual value in various cases where there is an accident risk in the work scaffold 110 , and may be given in advance. _{That is, by introducing α critical point} = f _d (β ₁ , β ₂ ) ≡ K from a physical quantity when there is a crack in the working scaffold 110 , K can be experimentally determined.

Referring to FIG. 11 , when the working scaffold 110 is stable, the accident risk α obtained from the time series measured first and second strain information has a value greater than the accident risk reference value K. If the accident risk α changes rapidly at any one point in time and becomes smaller than the accident risk reference value K, it can be determined to be dangerous.

Illustratively, the accident risk α may be understood as a function of a representative value representing the stress in the entire area of the working scaffold 110 , and the accident risk reference value K is a stress representative that can be determined to be safe in the working scaffold 110 . It may be the lower limit of the value α _{critical point.} When a crack occurs in the working scaffold 110 , since the stress is relieved at the corresponding site, the stress in the entire area of the working scaffold 110 may be reduced than usual, and the working scaffold 110 is not functioning properly. , that is, it can be determined to be in a dangerous state. Therefore, in this case, when the accident risk α is smaller than the accident risk reference value K, the work scaffold 110 may be determined to have an accident risk.

When the accident risk α is smaller than the accident risk reference value K, the work scaffold 110 determines that there is an accident risk and performs an operation of notifying an alarm (S350).

If the accident risk α is greater than the accident risk reference value K, the corresponding work scaffold 110 may be determined to be safe, and may return to step S310 again after a predetermined time (for example, 1 minute) has elapsed.

If a microcrack is generated in the working scaffold 110, the stress is momentarily relieved, and the accident risk α is sharply decreased, but if the crack does not spread, the accident risk α may be restored close to the original state again. If the accident risk reference value K is set conservatively (that is, when K is set relatively large), it can still be determined that there is an accident risk, but if the accident risk threshold value K is set relatively small, alarm notification may be stopped. it might be On the other hand, if the accident risk α is not smaller than the accident risk reference value K, but has an adjacent value, it may be determined that repair is required.

12 is a diagram illustrating generation of an accident risk reference value prediction model through machine learning according to an embodiment, and FIG. 13 is a diagram illustrating an accident risk reference value K determined through the accident risk reference value prediction model of FIG. 14 is a graph illustrating accident risk determination according to an embodiment.

,

과 작업 발판(110)의 물리량(예를 들어, 탄성계수, 자체질량, 폭, 너비, 등)은 작업 발판(110)의 균열발생과 밀접한 상관관계에 있다. 따라서, 다양한 경우에 대한 작업 발판(110)의 변형률

,

, 작업 발판(110)의 물리량 및 작업 발판(110)의 균열정보를 빅데이터로 수집함으로써 인공지능 기법을 활용할 수 있다. As described above, the strain measured in the working scaffold 110 .

,

And the physical quantity of the working scaffold 110 (eg, elastic modulus, self-mass, width, width, etc.) has a close correlation with the crack occurrence of the working scaffold 110 . Therefore, the strain rate of the working scaffold 110 for various cases

,

, it is possible to utilize the artificial intelligence technique by collecting the physical quantity of the working scaffold 110 and crack information of the working scaffold 110 as big data.

,

, 작업 발판(110)의 물리량 및 작업 발판(110)의 균열정보로 이루어진 학습데이터(410)를 신경망에 입력함으로서, 신경망에 대한 학습(training)(420)을 수행할 수 있으며, 이 결과 사고위험도 기준값 예측 모델(430)을 생성할 수 있다. 이와 같은 사고위험도 기준값 예측 모델(430)은 예를 들어 딥러닝 모델일 수 있다.Referring to FIG. 12 , the strain rate of the working scaffold 110 collected as big data

,

, by inputting the learning data 410 consisting of the physical quantity of the working scaffold 110 and the crack information of the working scaffold 110 to the neural network, training 420 for the neural network can be performed, and as a result, the accident risk A reference value prediction model 430 may be generated. The accident risk reference value prediction model 430 may be, for example, a deep learning model.

,

과 작업 발판(110)의 물리량으로 이루어진 입력값(510)을 사고위험도 기준값 예측 모델(520)에 입력하여, 그 출력값으로 사고위험도 기준값 K의 예측값(530)을 구할 수 있다.Referring to FIG. 13 , the strain rate of the working scaffold 110 in the accident risk reference value prediction model

,

An input value 510 consisting of a physical quantity and a physical quantity of the work scaffold 110 may be input to the accident risk reference value prediction model 520, and the predicted value 530 of the accident risk reference value K may be obtained as an output value.

The generation and utilization of the accident risk reference value prediction model 430 may be performed in the main processing server (220 in FIG. 1 ). Since the crack information of the working scaffold 110 for various cases can be continuously collected, the accident risk reference value prediction model can be continuously updated. As a result, the accident risk reference value K may be readjusted in real time.

Referring to FIG. 14 , the initial accident risk reference value K ₁ may be adjusted to K _{2 by machine learning.}

Illustratively, the accident risk α may be understood as a function of a representative value representing the stress in the entire area of the work scaffold 110 . In this case, even if a minute crack is generated in the working scaffold 110 and the stress is instantly relieved, and the accident risk α is sharply decreased, the accident risk α is changed again according to the degree of crack spread. If the stress is maintained stably after a predetermined time has elapsed after cracking, the accident risk α is maintained constant, and it can be seen that the uniformity generated in the working scaffold 110 is no longer spread. However, if the accident risk reference value K ₁ is conservatively set, when the accident risk α becomes _{smaller than the accident risk reference value K 1} , it can be determined that there is an accident risk as a result. However, as a result of checking the crack state of the working scaffolds 110 of the working scaffold assembly 100 managed by the server 200, even in this case, it can be determined that the risk of an accident is low, so the crack information of the working scaffold 110 is By supplementing, the accident risk standard value prediction model is continuously updated. In the updated accident risk standard value prediction model, the relaxed accident risk reference value K ₂ can be output. As a result, _{even if the accident risk α is smaller than the accident risk reference value K 1, it} becomes larger than the accident risk reference value K ₂ , and the corresponding work scaffold (110) ) may be judged to have a low risk of an accident, and as a result, the alarm notification may be stopped.

15 illustrates an example of a screen monitored by the on-site electronic device 230 (eg, a monitoring device) according to an exemplary embodiment. Referring to FIG. 15 , the field electronic device 230 displays a schematic diagram of a working scaffold (eg, A38) suspected of being cracked together with a schematic diagram of the entire working scaffold assembly 100, and the corresponding working scaffold (A38). By displaying the stress distribution diagram and accident risk graph for In addition, by synthesizing the stress analysis results for each of the plurality of work scaffolds 110 and outputting a safety index, it is possible to double the intuitiveness of safety monitoring.

In one embodiment, each worker carries an electronic device that outputs his/her location information (eg, a smart phone, a dedicated device installed in work clothes or a work helmet), and the server 200 is the It may also be possible to collect location information and give an accident hazard warning through an electronic device carried directly to the working scaffold A38 suspected of cracking or to a working scaffold adjacent thereto.

In one embodiment, the work scaffold 110 may be provided with a speaker or warning light that can issue a warning when it is determined that there is an accident risk such as cracks. In this case, the server 200 may issue a warning through a speaker or a warning light when a crack is suspected in the corresponding work scaffold 110 .

In one embodiment, by using the identification information or unique communication value assigned to each of the working scaffold 110, the visualization of the three-dimensional working scaffold assembly 100 may also be created automatically. As described above, when the on-site installation of the work scaffold 110 is completed, the 3D drawing data is automatically output to the monitor, so there is no need for a separate work process for establishing the monitoring system. can

The above-described method for detecting the stress of the working scaffold of the present invention and the working scaffold safety management system using the same have been described with reference to the embodiment shown in the drawings to help understanding, but this is only an example, and those of ordinary skill in the art It will be understood that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be defined by the appended claims.

100: working scaffold assembly 110: working scaffold
111: plate 112: mounting groove
113: coupling portion 119: frame
150: circuit part 151, 152: strain gauge
153: A/D converter 154: work platform communication unit
155: controller 156: battery
157, 158: wiring 170: assembly communication unit
200: server 210: web server
220: main processing server 230: field electronics

Claims (15)

In the method for detecting the stress of a working scaffold,
acquiring first and second strain information at the first and second positions using only first and second triaxial strain gauges disposed at different first and second positions of the working scaffold, respectively; and
Including; acquiring stress information at a plurality of places of the working scaffold only with the first and second strain information;
The first and second strain information is a stress detection method of a working scaffold, characterized in that the strain in the triaxial direction at the first and second positions of the working scaffold, respectively. According to claim 1,
Stress detection method of a working scaffold, characterized in that the stress information at a plurality of locations of the working scaffold is information about a stress distribution across the working scaffold. According to claim 1,
Stress information at a plurality of places of the working scaffold is obtained in time series,
The stress detection method of the working scaffold, characterized in that the crack of the working scaffold is predicted based on the time-series stress information at the plurality of locations. 4. The method of claim 3,
calculating the accident risk α of the working scaffold based on the correlation between time-series stress information at a plurality of locations of the working scaffold and cracks in the working scaffold;
Determining the presence or absence of an accident risk based on the accident risk degree α; Stress detection method of the work scaffold further comprising a. 5. The method of claim 4,
The accident risk α is a physical quantity converted from the first and second strain rates at the first and second positions obtained from the first and second three-axis strain gauges, and the accident risk α is at a plurality of locations of the work scaffold. Stress detection method of a working scaffold, characterized in that it is determined that there is an accident risk if it is less than the accident risk reference value K based on the correlation between the time-series stress information of and the crack of the working scaffold. 6. The method of claim 5,
Stress detection method of a working scaffold, characterized in that the feedback and correction of the accident risk reference value K based on the correlation between time-series stress information at a plurality of places of the working scaffold and the cracks of the working scaffold through machine learning. a working scaffold assembly in which a plurality of working scaffolds are assembled; and
It includes; a server that performs safety management for the working scaffold assembly.
Each of the working scaffolds of the plurality of working scaffolds is a plate-shaped plate and is disposed at first and second different positions of the plate to obtain first and second strain information at the first and second positions of the plate. First and second triaxial strain gauges acquired in time series, a working scaffold communication unit for transmitting the obtained first and second strain information to the outside, and the first and second triaxial strain gauges and the working scaffold communication unit It includes a working scaffold control unit for controlling the
The strain gauges provided on each of the working scaffolds are only the first and second three-axis strain gauges,
The first and second strain information is strain in the triaxial direction at the first and second positions of the plate material,
The server acquires time-series stress information at a plurality of places of the work scaffold based on only the first and second strain information for each of the plurality of work scaffolds, and time-series stress at a plurality of places of the work scaffold Working scaffold safety management system, characterized in that predicting the crack of the working scaffold based on the information. 8. The method of claim 7,
The work scaffold safety management system, characterized in that the time-series stress information at a plurality of places of the work scaffold is time-series information on the stress distribution across the work scaffold. 8. The method of claim 7,
The server calculates the accident risk of the working scaffold based on the correlation between time-series stress information at a plurality of places of the working scaffold and the crack of the working scaffold, and determines whether there is an accident risk based on the accident risk Working scaffold safety management system, characterized in that. 10. The method of claim 9,
In the server, the accident risk α converted from the first and second strains at the first and second positions obtained from the first and second triaxial strain gauges is the time-series stress at a plurality of places of the work scaffold. Work scaffold safety management system, characterized in that it is determined that there is an accident risk if it is less than the accident risk reference value K based on the correlation between the information and the crack of the working scaffold. 11. The method of claim 10,
A work scaffold safety management system, characterized in that it is corrected by feeding back an accident risk reference value K based on the correlation between time-series stress information at a plurality of places of the working scaffold and cracks in the working scaffold through machine learning. 10. The method of claim 9,
When it is determined that there is an accident risk in at least one of the plurality of work scaffolds, the server transmits accident risk information to a field electronic device that outputs an alarm to a control center or a site where the work scaffold assembly is installed. Work scaffold safety management system, characterized in that. 10. The method of claim 9,
The server, when it is determined that there is an accident risk in at least one of the plurality of work scaffolds, transmits accident risk information to the mobile device of the worker located in the work scaffold determined to have an accident risk Work scaffold safety management system. 10. The method of claim 9,
Working scaffold safety management system, characterized in that it further comprises a monitoring device for monitoring the accident risk of the working scaffold assembly. 15. The method of claim 14,
The monitoring device is at least one of an accident risk graph of each of the plurality of working scaffolds, a model diagram of a working scaffold determined to have an accident risk, and an overall model diagram of a working scaffold assembly in which the working scaffold determined to have an accident risk is displayed Work scaffold safety management system, characterized in that to display.

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