KR101996017B1 - A safety management system based on beacon by changing transmitting strength periodically - Google Patents

Abstract

The present invention relates to a method and apparatus for periodically changing a dispensing intensity of a beacon, a moving object receiving a periodic beacon signal, estimating a distance from the dangerous object using the dispensing intensity and the measured signal intensity, Based IoT safety management system, a beacon which is installed in a dangerous object and transmits a signal with a periodically different transmission intensity; And a worker terminal for receiving a signal transmitted from the beacon, measuring a received signal strength of the received signal according to transmission intensity, and estimating a distance to the dangerous object using the received signal strength for each of the measured transmission strengths And a configuration is prepared.
According to the above-described system, when the beacon transmission intensity is different, the maximum distance that the signal reaches and the distance can be classified according to the signal intensity within the maximum distance for each transmission intensity. The risk signal can be generated more accurately.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a beacon-based IoT safety management system,

The present invention relates to a beacon-based IoT safety management system using a periodic change in dispatch intensity, in which a beacon is installed in a dangerous object, a moving object senses a beacon signal to estimate a distance from the dangerous object,

More particularly, the present invention relates to a method and apparatus for periodically changing a transmission intensity, which periodically changes a transmission intensity of a beacon, receives a periodically changed beacon signal and estimates a distance from the dangerous object using the transmission intensity and the measured signal intensity Based IoT safety management system using a beacon-based IoT security management system.

In general, the construction industry is a labor-intensive industry in which a large number of workers are put into operation at the same time, and systematic and effective safety management of the workforce is of the utmost importance. However, in the conventional construction site, safety accidents occur frequently due to various environments inherent in the site itself and minor negligence of workers, resulting in a fatal problem of losing valuable human resources.

Especially, in the construction site, since various works are performed simultaneously in various tools, workers in various fields are simultaneously arranged to perform their respective tasks. In many cases, the number of managers is relatively small compared to the number of such workers. Therefore, efficient and accurate management of the construction workforce is not achieved in the area where the control and management of the field manager is limited in the outdoor work. Inefficient workforce management for the construction workforce not only increases the risk of safety accidents, Increase of construction cost, decrease of productivity, and extension of construction period.

In order to solve such a problem, a beacon is used to identify a location, an event is generated in a dangerous situation, and event information is transmitted to an operator or a moving object, Technology has been proposed [Patent Document 1]. In addition, a technology for tracking the position of construction equipment using a beacon and a receiver has been proposed [Patent Document 2]. However, the prior arts have a limitation in that a plurality of beacons must be installed in each area by dividing the work site into work areas at regular intervals. That is, there are limitations in installing a large number of beacons in various places in the worksite.

 In addition, beacons are provided to workers located at work sites, beacons are provided to work machines, and workers who are located within a certain range based on work machines are recognized by recognizing beacons of workers. And technologies for securing it have been proposed [Patent Literature 3, 4]. In this case, the prior arts must measure the location or distance of the beacon using the beacon signal. That is, a method of measuring a distance of at least one of a time of arrival (TOA) of a signal, a time difference of arrival (TDOA), or a received signal strength indicator (RSSI) The position of the beacon can be measured. In this case, in particular, when receiving a signal of one beacon, the distance between the beacon-installed dangerous object and the moving object receiving the signal is measured using the signal strength.

However, when a single beacon is actually used, it is often impossible to measure an accurate distance by the beacon signal strength. That is, there is a problem that the error of the distance measurement due to the signal strength is too large. For example, since a signal intensity of a similar size is measured within a considerable distance of 5 m to 10 m, it is difficult to measure the distance accurately.

Korean Registered Patent No. 10-1736158 (issued on May 17, 2017) Korean Patent Registration No. 10-1695904 (published on January 16, 2017) Korean Patent Laid-Open Publication No. 10-2016-0127881 (published on July 11, 2016) Korean Patent Laid-Open Publication No. 10-2016-0112048 (published on September 28, 2016)

It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide an apparatus and method for detecting a beacon signal, And to provide a beacon-based IoT safety management system that uses a periodic change in dispatch intensity to estimate distance.

According to another aspect of the present invention, there is provided a beacon-based IoT safety management system for periodically changing emission intensity according to an embodiment of the present invention. And an operator terminal for receiving a signal transmitted from the beacon, measuring a received signal strength of the received signal according to the intensity of the transmitted signal, and estimating a distance to the dangerous object using the received signal strength for each of the plurality of transmitted strengths, The beacon transmits a signal with a plurality of changed intensities in each cycle at a predetermined cycle. The operator terminal measures a received signal strength of a signal having the lowest transmission intensity among the plurality of measured signal strengths And estimates a distance to the dangerous object by using the beacon signal. The signal transmission intensity of the plurality of stages transmitted in one period of the beacon is different in each step.
In this case, the operator terminal can estimate the distance to the dangerous object using only the received signal strength of the signal having the lowest transmission intensity.
In addition, the operator terminal can estimate the distance by averaging received signal strengths for a plurality of transmission strengths including the reception signal strength of the signal having the lowest transmission strength.
In addition, the operator terminal estimates a distance by weighting a received signal strength of a plurality of transmission strengths including a reception signal strength of a signal having the lowest transmission strength, and estimates a distance, The weight can be increased.

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In this case, in the beacon-based IoT safety management system using the cyclic change of the emission intensity, the distance d can be estimated from the received signal strength for each of a plurality of transmission strengths by using Equation 1 below.

[Equation 1]

Where r is the received signal strength of the signal of the k th transmit power, d _k (r) is the distance estimated from the signal of the k th transmit power, and e _k is the received signal strength of k Is the error of the distance estimated from the signal of the emission intensity.

As described above, according to the beacon-based IoT safety management system using the cyclic change of the emission intensity according to the present invention, when the emission intensity of the beacon is changed, the maximum distance that the signal reaches becomes different, The effect of distinguishing the distances according to the intensity can be obtained.

Particularly, according to the beacon-based IoT safety management system using the cyclic change of the emission intensity according to the present invention, if the emission intensity is high, even if the distance accuracy is low, it can be recognized in a wider range. The effect of increasing the accuracy of distance can be obtained.

In addition, according to the beacon-based IoT safety management system using the cyclic change of the emission intensity according to the present invention, the closer the beacon is, the more accurate the distance can be measured and the danger signal can be generated more accurately.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an entire system for implementing the present invention. FIG.
FIG. 2 is a graph showing transmission intensity of a periodically transmitted signal in time order according to an embodiment of the present invention; FIG.
FIG. 3 is an exemplary diagram illustrating a data frame structure of beacon data according to an embodiment of the present invention; FIG.
FIG. 4 and FIG. 5 are diagrams illustrating a reception range according to transmission intensity according to an embodiment of the present invention; FIG.
FIG. 6 is a flowchart illustrating a beacon-based IoT security management method using a periodic change of dispatch strength according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

In the description of the present invention, the same parts are denoted by the same reference numerals, and repetitive description thereof will be omitted.

First, a configuration of an overall system for carrying out the present invention will be described with reference to FIG.

1, the overall system for implementing the present invention includes a dangerous object 10 installed in an industrial site, a beacon 20 provided in a dangerous object 10, a worker terminal 50 carried by an operator 80, , And a safety management app (30).

Hazardous material (10) is an object installed at an industrial site, and is a dangerous object having a dangerous element. For example, the hazardous material 10 is a dangerous or careful approaching object such as a gas tank, a switchboard, a work elevator, or a crane. In addition, the dangerous object 10 may be a moving object. For example, the hazardous material 10 may be construction equipment such as excavators (forklifts), dump trucks, bulldozers, cranes, augers, forklifts and the like.

Next, the beacon 20 is a short-distance wireless communication module installed in the dangerous goods 10.

Preferably, the beacon 20 is a short range wireless communication signal transmitter implemented on a Bluetooth 4.0 LE (Low Energy) basis. Unlike Bluetooth 3.0, Bluetooth 4.0 has the advantage that no pairing is required. In addition, the power consumption is very low and the price is low, so that it can be constructed at low cost. Preferably, the beacon 20 can communicate using UWB (Ultra Wide Band) or UHF (Ultra High Frequency) method, but the present invention is not limited thereto.

On the other hand, the beacon 20 periodically changes the transmission strength and transmits it. As the transmission intensity increases, the signal of the beacon 20 can be received at a long distance, and the signal of the beacon 20 can be received at a closer distance as the transmission intensity becomes smaller.

Next, the worker terminal 50 is a smart terminal having ordinary computing functions such as a smart phone, a tablet, and a tablet PC as a mobile terminal used by the worker. In particular, the worker terminal 50 is a terminal to which an application or a mobile application (or an app, an application) can be installed and executed.

The worker 80 is a person who performs work in an industrial field.

The worker terminal 50 incorporates a Bluetooth device or the like and receives a signal transmitted by the beacon 20. At this time, the worker terminal 50 receives the signal data transmitted by the beacon 20 and measures the strength of the received signal.

Next, the safety management application 30 is a mobile application (or an app, application) installed in the worker terminal 50 and is a program for providing a service for notifying the danger of the dangerous object 10 System.

That is, the safety management app 30 estimates the distance from the dangerous object 10 using the signal data received from the beacon 20 and the intensity of the received signal.

In addition, the safety management app 30 outputs an alarm notifying the danger when the distance to the dangerous object 10 is estimated to be within a predetermined distance. At this time, a warning sound is output through a speaker or a warning message is outputted as a sound.

Next, a signal transmission method of the beacon 20 according to an embodiment of the present invention will be described with reference to FIG. 2 to FIG.

First, the emission intensity is divided into a plurality of intensity steps, and the change period is predetermined as a predetermined value. For example, the emission intensity is divided into four steps of 4 dBm, -12 dBm, -20 dBm, -30 dBm, and the change period is set to 400 ms. That is, each step is transmitted for 100 ms and changed to the transmission intensity of the other step. Therefore, the emission intensity of all the stages is transmitted once within the change period of 400 ms.

FIG. 2 is a graph showing each transmission intensity in time order according to the above example.

As shown in FIG. 2, the beacon 20 transmits a signal from a time of 100 ms to a level of +4 dBm, and transmits a signal by changing its intensity to -12 dBm at a time of 200 ms. Then, the signal is transmitted by changing its intensity to -20 dBm at 300 ms, and its intensity is changed by -30 dBm at 400 ms. Then, at 500ms again, the signal is transmitted at the intensity of the first stage +4 dBm. That is, the beacon 20 transmits a signal at a changed intensity in four steps within each cycle at a cycle of 400 ms.

The beacon 20 includes a beacon position information (or position identification information, beacon identification information) UUID, an object identification information (major / minor number), a transmission strength (TX Power) And transmits the signal data. An example of a data frame structure of beacon data is shown in Fig.

As shown in FIG. 3, the beacon data includes a prefix, position information or UUID, object identification information (Major / Minor Number), and transmission strength (TX Power).

The prefix includes information on beacon data such as a company ID, a beacon type, and a data length.

Also, the location information UUID indicates unique identification information including location information on which the beacon 20 is installed. That is, the location where the beacon 20 is installed can be known through the unique identification information on the location.

In addition, the object identification information (Major / Minor Number) is information for identifying the object on which the beacon 20 is installed, and is composed of a main identification number (Major Number) and a minor identification number (Minor Number). Through the object identification information, it is possible to know whether the object in which the beacon is installed is the operator, the forklift, the eyepiece dock, the rack, or the like. In addition, when a plurality of beacons 20 are installed in one object, it is possible to know at which position the object is installed.

Also, the transmission power (TX Power) indicates the step of the transmission intensity. In the example described above, the transmission strengths of 4 dBm, -12 dBm, -20 dBm, and -30 dBm are represented by 1, 2, 3, and 4 levels, respectively, and can be identified by numbers of 1, 2, 3, and 4, respectively.

Next, a method for estimating the position of a dangerous object by receiving a beacon signal according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG.

The worker terminal 50 receives the beacon signal, and measures the intensity of the beacon signal at this time. That is, the distance between the beacon 20 and the dangerous object 10 equipped with the beacon 20 is estimated using received signal strength indication (RSSI) of the beacon signal.

The range of the received signal strength of the beacon signal in the worker terminal 50 (or the Bluetooth device built in the worker terminal) is roughly determined. Alternatively, the range of the received signal strength can be set in advance through an experiment.

For example, if the beacon 20 is closest (e.g., within 1 m), the intensity of the beacon signal measured at the worker terminal 50 is -40 dBm. When the beacon 20 is farthest from the base station, the received signal strength measured at the worker terminal 50 is about -90 dBm.

The range measurable by the operator terminal 50 is determined by the intensity of the signal transmitted from the beacon 20, that is, the intensity of the transmitted signal.

In the above example, when the transmission intensity of the beacon 20 is +4 dBm, the signal can be received within a range of 25 m or less. When the dangerous object 10 is present at a distance of about 25 m from the worker terminal 50 and the beacon 20 transmits a signal with a transmission intensity of +4 dBm, a signal of about -90 dBm is transmitted from the worker terminal 50 Receive the beacon signal by intensity.

In addition, when the transmission strength of the beacon 20 is -12 dBm, signals can be received within a range of 20 m, and when the transmission strength is -20 dBm, signals can be received within a range of 15 m. Also, when the transmitting intensity is -30 dBm, signals can be received within a range of 10 m.

At this time, within the receivable range, the received signal strength (RSSI) measured at the worker terminal 50 and the distance between the worker terminal 50 and the beacon 20 have a proportional relationship.

Therefore, when the transmission intensity is k stages, the distance according to the received signal strength can be expressed as Equation (1).

[Equation 1]

Where d _k (r) is the distance estimated when the transmitted intensity is k steps and the received signal strength is r. And D ₀ is the closest distance that can be estimated, and is set in advance. For example, D ₀ is set to 1m. D _k is the farthest distance at which the signal is received when the emission intensity is k stages and is set in advance. For example, when k = 1, 2, 3, and 4, it is set to 25 m, 20 m, 15 m, and 10 m, respectively.

Also, R _max and R _min are constants preset in advance as the maximum and minimum values of the received signal strength. For example, R _max and R _min are set to -40 dBm and -90 dBm, respectively.

The reception range is shown in FIG. 4 according to the intensity level of the transmission intensity of the beacon 20.

As shown in Fig. 4, the smaller the transmitting intensity, or the higher the intensity level, the wider the receiving range. That is, if the transmission intensity is the largest in one step, the reception range is widened to D1, and as the transmission intensity is reduced to 2, 3, and 4, the reception range becomes smaller by D2, D3 and D4.

Instead, in all cases, the range DELTA R of the measured received signal strength is the same as in Equation (2). For example, in all intensity stages, the intensity range of the received signal is within -90 dBm at -40 dBm, i.e., 50 dBm.

&Quot; (2) "

△ R = R _max - R _min

However, as shown in FIG. 5, when the transmission intensity is one level, the range of D1-D0 is estimated by measuring the reception intensity range? R to be measured. On the other hand, when the transmission intensity is in the 4th step, the range of D4-D0 is estimated by measuring with the same reception intensity range DELTA R.

That is, the higher the emission intensity, the shorter the signal reach distance, but the higher the accuracy can be. For example, assume that there is an error of 10% when estimating the distance from the signal strength.

If the dispatch intensity is one level, the following error occurs.

(D1-D0) 占 10% error = (25m-1m) 占 10% = 2.4m

If the emission intensity is 4 steps, the following error occurs.

(D4-D0) 占 10% error = (10m-1m) 占 10% = 0.9m

If the display error e _k at each stage k, the same mathematical equation, and then.

&Quot; (3) "

Here, E ₀ is a constant that is determined in advance as an error rate.

Therefore, it is more accurate to estimate the distance from the signal intensity of the received beacon, but to estimate the distance from the signal corresponding to the smallest step of transmitting intensity (signal transmitting at the highest intensity).

In FIG. 4, when the operator terminal 50 is located at the point A, the operator terminal 50 can detect only the signal when the sending intensity is one level.

When the worker terminal 50 is located at point B, only the signal when the dispatch intensity is one step and two stages can be detected. When the worker terminal 50 is at the point C, the dispatch intensity is one step, It is possible to detect the signal of the case.

Finally, when the worker terminal 50 is located at the point D, it is possible to detect a signal of transmission strength at all stages.

Therefore, when the operator terminal 50 receives a signal from a plurality of transmitted intensities, the distance to the dangerous object 10 can be estimated using the received signal strength of the signal having the lowest transmitted intensity as follows.

In one embodiment, the worker terminal 50 estimates the distance from the received signal strength of the highest-level transmitting intensity among the receiving signals of the plurality of transmitting intensity levels. That is, the distance is directly estimated from only the received signal strength of the signal having the lowest transmission intensity.

In another embodiment, the operator terminal 50 estimates the distance by averaging received signals at a plurality of transmission intensity levels including the reception signal strength of the signal having the lowest transmission intensity.

In another embodiment, the operator terminal 50 estimates the distance by averaging received signals of a plurality of transmission intensity stages including the reception signal strength of the signal having the lowest transmission intensity, and increases the weight as the transmission intensity level is higher Weighted averages. That is, the lower the transmission intensity, the higher the weight of the received signal strength of the transmission intensity.

In particular, preferably, the weight is set to be in inverse proportion to the distance estimation error e _k of the received signal strength of the transmission strength.

That is, a formula for estimating the distance d from the received signal strength for a plurality of transmission strengths can be expressed as follows.

&Quot; (4) "

Here, n represents the number of signals according to the received transmission intensity.

Next, a beacon-based IoT safety management method using a periodic change of emission intensity according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 6, first, the beacon 20 of a dangerous object periodically transmits a signal at different dispensing strengths (S10). If the total period is T and the types of emission intensity are all N, the signal corresponding to each emission intensity is divided by the same time interval (T / N) during the period T. [ That is, if the total period is 400ms and the transmission intensity is 4, the signal is divided into 100ms and transmitted at each transmission intensity for each time.

Next, the operator terminal 50 receives the signal for the entire period T and extracts the strength of the received signal for each transmission intensity (S20). For example, when four types of transmission intensity are used, signals for four transmission intensities are received during the entire period T. FIG. Then, the strength of the received signal of the signal according to the transmission intensity is obtained.

At this time, it is possible to receive signals for m times of the entire period T, obtain m received signal strengths from m signals for each transmission strength, and average them. That is, m signal strengths are averaged to obtain the received signal strength for each transmission strength.

Next, the distance is estimated from the signal strengths according to a plurality of transmission strengths (S30).

At this time, the distance is estimated from the received signal strength of the signal having the smallest transmission strength among the plurality of reception signals for each transmission strength. Distance is estimated by Equation (1).

Alternatively, the distance is averaged by averaging the received signals for a plurality of transmission strengths, and weighted averaging is performed by increasing the weight as the transmission strength is low.

Next, it is determined whether the estimated distance is equal to or less than the threshold value (S40). If the estimated distance is less than or equal to the threshold value, it is determined that the estimated distance is close to the dangerous object. At this time, it is possible to generate a plurality of threshold values with different degrees of alarm for each step.

If the estimated distance is greater than or equal to the threshold value, the process returns to step S20 to repeat the process.

Although the present invention has been described in detail with reference to the above embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

10: Dangerous goods 20: Beacon
30: safety management app 50: worker terminal
80: Worker

Claims (5)

In a beacon-based IoT safety management system using a periodic change in dispatch intensity,
Beacons installed in dangerous goods and emitting signals with periodically different emission intensity; And
An operator terminal for receiving a signal transmitted from the beacon, measuring a received signal strength of the received signal according to the intensity of the transmitted signal, and estimating a distance to the dangerous object using the received signal strength for each of the plurality of transmitted strengths;
/ RTI >
The beacon includes:
Characterized in that a signal is transmitted with a plurality of stages of changed intensity within each cycle at a predetermined cycle,
The worker terminal,
The distance to the dangerous object is estimated using the received signal strength of the signal having the lowest transmission intensity among the received signal strengths of the plurality of measured transmission strengths,
Wherein the beacon-based IoT safety management system is characterized in that a plurality of signal transmission intensities transmitted in one cycle are different for each step.
The method according to claim 1,
Wherein the beacon-based IoT safety management system uses a cyclic change of dispatch intensity to estimate the distance from the received signal strength of the signal having the lowest transmission intensity to the dangerous object.
The method according to claim 1,
Wherein the beacon-based IoT safety management system is based on a periodic change in dispatch intensity, wherein a distance is estimated by averaging received signal strengths of a plurality of dispatch strengths including a received signal strength of a signal having the lowest dispatch strength.
The method according to claim 1,
The distance is estimated by weighted averaging of the received signal strengths of the plurality of transmitting strengths including the receiving signal strength of the signal having the lowest transmitting strength so as to increase the weight of the received signal strength of the transmitting intensity as the transmitting intensity is low A beacon - based IoT safety management system using periodic change of emission intensity.
5. The method of claim 4,
A beacon-based IoT safety management system using a cyclic change of dispatch intensity, characterized by estimating a distance d from received signal strengths for a plurality of dispatch strengths using Equation (1).
[Equation 1]

Where r is the received signal strength of the signal of the k th transmit power, d _k (r) is the distance estimated from the signal of the k th transmit power, and e _k is the received signal strength of k Is the error of the distance estimated from the signal of the emission intensity.

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