WO2016088943A1

WO2016088943A1 - Method and device for detecting trespassing in smart home security system

Info

Publication number: WO2016088943A1
Application number: PCT/KR2015/002884
Authority: WO
Inventors: 김현국
Original assignee: 주식회사 에스원
Priority date: 2014-12-05
Filing date: 2015-03-24
Publication date: 2016-06-09

Abstract

A method and a device for detecting trespassing in a smart home security system are disclosed. The trespassing detection device measures the strengths of signals received from a plurality of radio devices and calculates change values of the measured reception signal strength. In addition, the trespassing detection device calculates a reception signal strength change probability by using the calculated reception signal strength change values, and determines whether a trespasser has trespassed by comparing the reception signal strength change probability with a predetermined threshold value.

Description

Method and device for detecting intrusion in smart home security system

The present invention relates to a method and apparatus for detecting an intrusion in a smart home security system.

Smart home security system is a system that detects anti-theft or unauthorized intruders in the home. In order to build such a home security system, it is inconvenient to separately install a plurality of security sensors (for example, a hot wire sensor, a sound wave sensor, an infrared sensor, etc.) and a controller for control. Then, the cost of installing these sensors and controllers increases, which puts pressure on the consumer.

On the other hand, in order for the smart home security system to operate, a large number of sensors and controllers must be operating all the time, which causes a problem of an increase in electric charges. In the case of using such a security sensor, it is difficult to maintain and repair because new construction is required to remodel, move, or change the internal structure.

The problem to be solved by the present invention is to provide a method and apparatus that can detect the intrusion without installing a separate security sensor.

According to an embodiment of the present invention, a method for detecting an intruder by an intrusion detecting device that performs wireless communication with a first wireless device and a second wireless device, respectively. The method includes measuring a first received signal strength, the strength of a signal received from the first wireless device, measuring a second received signal strength, the strength of a signal received from the second wireless device, Calculating a received signal strength change value using the first received signal strength and the second received signal strength, calculating a received signal strength change probability using the received signal strength change value, and receiving the received signal The method may include determining whether the intruder is invasive by comparing a signal strength change probability with a predetermined threshold.

The intrusion detection device may perform wireless communication with a third wireless device, and the method may further include measuring a third received signal strength, which is a strength of a signal received from the third wireless device, The calculating of the received signal strength change value may include calculating the received signal strength change value by using the first to third received signal strengths.

The determining may include determining that the intruder is invading when the probability of change of the received signal strength is greater than the threshold.

The received signal strength change value may be a value obtained by subtracting an average value from the first received signal strength and the second received signal strength, respectively.

The received signal strength change probability may satisfy the following equation,

In the above equation, N is the total number of wireless devices including the first and second wireless devices, z is the received signal strength change value,

Represents the covariance of z

Can be.

The calculating of the received signal strength change probability may include calculating the received signal strength change probability using the square of the change value of the received signal strength and the variance of the received signal strength.

The first wireless device may be a ZigBee device and the second wireless device may be a wireless LAN device.

The intrusion detection device may be a smart gateway, and the first and third wireless devices may be ZigBee devices, and the second wireless device may be WLAN devices.

The intrusion detection device may be a terminal, the first wireless device may be a base station, the second wireless device may be a WLAN AP, and the third wireless device may be a Bluetooth device.

The method may further include transmitting an intrusion notification to the control server when it is determined that the intruder has intruded in the determining step.

According to another embodiment of the present invention, an intrusion detection apparatus is provided. The intrusion detecting apparatus may include an RF receiver configured to receive signals transmitted from a plurality of wireless devices, a received signal strength measurer configured to measure a received signal strength that is the strength of the received signal, and the measured received signal strength. A received signal strength change value calculator for calculating a received signal strength change value, a probability calculator for calculating a received signal strength change probability using the received signal strength change value, and the received signal strength change probability and a predetermined threshold value By comparing the, it may include an intrusion determination unit for determining the intruder.

The intrusion determining unit may determine that the intruder enters when the probability of change of the received signal strength is greater than the threshold value.

The received signal strength change value calculator may calculate the received signal strength change value by subtracting an average value from the measured received signal strengths, respectively.

Represents the covariance of z

Can be.

The received signal strength change probability may correspond to a square of the received signal strength change value and the variance of the measured received signal strength.

The plurality of wireless devices may include a ZigBee device and a wireless LAN device.

The plurality of wireless devices may include a base station, a WLAN AP, and a Bluetooth device.

According to an embodiment of the present invention, it is possible to determine whether an intruder is invasive by measuring a received signal strength of a signal received from a wireless device without a separate security sensor.

1 is a view showing a smart home security system according to an embodiment of the present invention.

2 is a diagram illustrating a smart home security system according to another embodiment of the present invention.

3 is a diagram illustrating a method of determining intrusion through received signal strength according to an embodiment of the present invention.

4 is a diagram illustrating an intrusion detecting apparatus for determining whether an intrusion is made through received signal strength according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, a terminal may be a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station (HR-MS). ), A subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a user equipment (UE), or the like. It may include all or part of the functionality of AMS, HR-MS, SS, PSS, AT, UE, and the like.

In addition, a base station (BS) may be an advanced base station (ABS), a high reliability base station (HR-BS), a node B (node B), an advanced node B (evolved node B, eNodeB), access point (AP), radio access station (RAS), base transceiver station (BTS), mobile multihop relay (MMR) -BS, relay serving as a base station station, RS), a high reliability relay (HR-RS) serving as a base station, etc., and may also refer to ABS, Node B, eNodeB, AP, RAS, BTS, MMR-BS, RS, HR. It may include all or part of functions such as -RS.

Smart home security system according to an embodiment of the present invention easily analyzes the intrusion by using a base station, a wireless LAN (WiFi), Bluetooth, ZigBee, Z-wave, a terminal that is a widely used wireless heterogeneous system can do. In other words, the smart home security system according to the embodiment of the present invention detects the intrusion by synthesizing a wireless heterogeneous signal. Such an embodiment of the present invention will be described in detail below.

As shown in FIG. 1, the smart home security system according to an embodiment of the present invention includes a base station 100, a wireless LAN AP (Access Point) 200, a Bluetooth device 300, a terminal 400, a gateway 500, and The control server 600 is included.

The base station 100 performs cellular communication for transmitting and receiving signals with the terminal 400 belonging to the base station. In addition, the base station 100 according to an exemplary embodiment of the present invention transmits a pilot signal S1 for measuring received signal strength (RSS) at regular time intervals. Here, the pilot signal S1 for RSS measurement may be a pilot signal specifically transmitted by the base station 100 for smart home security or may be a pilot signal used for general signal transmission.

The WLAN AP 200 performs Wi-Fi communication with the terminal 400. In addition, the WLAN AP 200 according to an embodiment of the present invention transmits a pilot signal S2 for RSS measurement at regular time intervals. Here, the pilot signal S2 for measuring RSS may be a pilot signal specifically transmitted by the WLAN AP 200 for smart home security or may be a pilot signal used for general signal transmission.

The Bluetooth device 300 performs Bluetooth communication with the terminal 400. Although FIG. 1 shows that the Bluetooth device 300 is installed in the TV, it can be installed in other home devices besides the TV. Meanwhile, the Bluetooth device 300 transmits a pilot signal S3 for RSS measurement at regular time intervals. Here, the pilot signal S3 for RSS measurement may be a pilot signal specifically transmitted by the Bluetooth device 300 for smart home security or may be a pilot signal used for general signal transmission.

The terminal 400 measures the strength (RSS) of the received signal for the pilot signal S1 received from the base station 100 and the strength of the received signal for the pilot signal S2 received from the WLAN AP 200 ( Measure RSS). In addition, the terminal 400 measures the strength (RSS) of the received signal with respect to the pilot signal S3 received from the Bluetooth device 300. The terminal 400 synthesizes and analyzes the strength of the received signal measured through the pilot signals received from the wireless

heterogeneous devices

100, 200, and 300, and determines whether an intruder enters through the signal analysis. Meanwhile, the terminal 400 may be a smartphone capable of 3G communication or LTE communication, and equipped with a Bluetooth communication module and a wireless LAN communication module.

The signal transmitted between the base station 100 and the terminal 400 has a substantially constant value (RSS) of the received signal when there is no intrusion. However, if there is an intrusion, the received signal strength (RSS) has a large fluctuation range. In addition, the intrusion of the received signal strength (RSS) of the signal transmitted between the WLAN AP 200 and the terminal 400, and the received signal strength (RSS) of the signal transmitted between the Bluetooth device 300 and the terminal 400 is also invasive. If present, it has a large variation. The terminal 400 according to an exemplary embodiment of the present invention determines whether an intruder enters by using the fluctuation range of the received signal strength RSS.

The terminal 400 transmits the intrusion information to the base station 100 when it is determined that the intruder has invaded using the fluctuation range of the received signal strength RSS, and the base station 100 transmits the intrusion information to the gateway 500 again. Transmit to the control server 600 through. The intrusion information transmitted to the control server 600, the control agent finally confirms, the control agent may dispatch to confirm the site situation or contact the police.

As shown in FIG. 2, the smart home security system according to another embodiment of the present invention includes a smart gateway 700, a

ZigBee device

800, 800 ′, 800 ″, a WLAN device 900, and a gateway 500. And a control server 600.

The smart gateway 700 includes a ZigBee communication module and a Wi-Fi communication module therein. The smart gateway 700 performs short-range communication with the Zigbee devices 800, 800 ', and 800' 'through the internal ZigBee communication module. The smart gateway 700 communicates with the WLAN device 900 through an internal Wi-Fi (Wireless LAN) communication module.

The

ZigBee devices

800, 800 ′, and 800 ″ perform ZigBee communication with the smart gateway 700, respectively. In addition, the

Zigbee devices

800, 800 ′, 800 ″ according to an embodiment of the present invention transmit the pilot signals S4, S4 ′, S4 ″ for RSS measurement to the smart gateway 700 at regular time intervals, respectively. do. Here, the pilot signals S4, S4 ', and S4 " for RSS measurement may be pilot signals that the

ZigBee devices

800, 800', and 800 " transmit specifically for smart home security, and are used for general signal transmission. It may be a pilot signal. The ZigBee device 800 may be installed in an air conditioner, the Zibee device 800 'may be installed in a boiler, and the ZigBee device 800' 'may be installed in a refrigerator. Meanwhile, unlike FIG. 2, the

ZigBee devices

800, 800 ′, and 800 ″ may be installed in different home appliances, respectively. In FIG. 2,

ZigBee devices

800, 800 ′, and 800 ″ are illustrated as local area communication devices, but a Z-Wave device may be used.

The WLAN device 900 performs Wi-Fi communication with the smart gateway 700. The WLAN apparatus 900 according to an embodiment of the present invention transmits a pilot signal S5 for RSS measurement at regular time intervals. Here, the pilot signal S5 for measuring the RSS may be a pilot signal specifically transmitted by the WLAN apparatus 900 for smart home security or may be a pilot signal used for general signal transmission. Although FIG. 2 shows that the WLAN apparatus 900 is installed in the TV, it can be installed in other home devices besides the TV.

The smart gateway 700 measures the strength (RSS) of the received signal for the pilot signals S4, S4 ', and S4 " received from each ZigBee device (800, 800', 800 "). The gateway 700 measures the strength (RSS) of the received signal with respect to the pilot signal S5 received from the WLAN device 900. The terminal 400 is a wireless heterogeneous type 800, 800 ', 800' ', The strength of the received signal measured by the pilot signal received from the 900 is synthesized and analyzed, and the signal analysis determines whether the intruder is invading.

The signal transmitted between the smart gateway 700 and each

ZigBee device

800, 800 ′, 800 ″ has a substantially constant value (RSS) of the received signal when there is no intrusion. However, if there is an intrusion, the received signal strength (RSS) has a large fluctuation range. In addition, the received signal strength (RSS) of the signal transmitted between the smart gateway 700 and the WLAN device 900 also has a large fluctuation range in case of intrusion. The smart gateway 700 according to an embodiment of the present invention determines whether an intruder enters by using the fluctuation range of the received signal strength RSS.

The smart gateway 700 transmits the intrusion information to the gateway 500 when it is determined that the intruder has invaded using the fluctuation range of the received signal strength (RSS), and the gateway 500 transmits the intrusion information to the control server 600. To send. The intrusion information transmitted to the control server 600, the control agent finally confirms, the control agent may dispatch to confirm the site situation or contact the police.

Next, in the smart home security system as shown in Figure 1 or 2, the terminal 400 or the smart gateway 700 according to an embodiment of the present invention measures and analyzes the received signal strength (RSS) transmitted from each wireless device A method of determining whether an intruder is invading will be described in detail with reference to FIG. 3. In FIG. 3, for convenience of description, a method of determining whether an intrusion is performed by the smart gateway 700 will be described. However, the following description may be applied to a method of determining whether an intrusion is performed by the terminal 400. In the following description, the

ZigBee devices

800, 800 ′, 800 ″ and the wireless LAN device 900 will be collectively described as “wireless devices”.

First, the smart gateway 700 measures a received signal strength (RSS) for a signal received from each wireless device (800, 800 ', 800' ', 900) (S310). That is, the smart gateway 700 measures the received signal strength (RSS) of the pilot signal received from each ZigBee device (800, 800 ', 800' '), and measures the pilot signal received from the WLAN device (900). The received signal strength (RSS) is measured.

When the received signal strength (RSS) measured by the smart gateway 700 is N (N = 4 in FIG. 2), the measured received signal strength (RSS) is expressed by a formula below. same.

Equation 1

In Equation 1, y _N represents the received signal strength measured by the smart gateway 700 through the signal received from the Nth wireless device. y _N may be represented by received signal strength rss _N and measured noise n _N. It is assumed that the received signal strength rss _N has a Gaussian distribution of N (mu _N , σ _N ² ). Where mu _N is the mean value and sigma _N is the standard deviation. When intrusion occurs, sigma _N ² has a very small value, but when intrusion occurs, it has a very large value.

Next, the smart gateway 700 calculates a change value of the received signal strength (RSS) excluding a constant average value from the measured received signal strength (RSS) value (S320). When the RSS change value is expressed as an equation, Equation 2 below.

Equation 2

Z in Equation 2 represents the RSS change value,

Represents the average value of RSS. Average value (

) Is a predetermined value through an experimental method.

The smart gateway 700 calculates an RSS change probability using the RSS change value z calculated in step S320 (S330). Assuming that Equation 2 has a multivariate Gaussian distribution, the probability of RSS change for the case of no intruder intrusion (H ₀ ) is given by Equation 3 below. The distributions are independent but may have different variances due to the environmental characteristics of the area in which each wireless device is installed.

Equation 3

In Equation 3,

Denotes the covariance of the RSS change value (z),

Can be expressed as When there is an intruder's intrusion (H ₁ ) is the same except that H ₀ is replaced by H ₁ in the equation (3).

Since each wireless device has independent statistical characteristics, Equation 3 can be simply expressed as Equation 4 below.

Equation 4

As shown in Equation 4, the RSS change probability (

) Is the square of the change in RSS for each wireless device (

)

), And the sum of all wireless devices. That is, utilizing Equation 4, the RSS change probability can be simply calculated. Where the square of the RSS change value (

) Corresponds to a power change value of a signal received from each wireless device.

Next, the smart gateway 700 calculates a threshold value (θ) used to determine whether an intruder is invading (S340). As shown in Equation 4, the RSS change probability may be simply calculated, and the threshold value θ may be calculated based on a desired misinformation. When the smart gateway 700 calculates using an approximation equation (for example, an approximation equation of Q function) or applies a look-up table, the threshold value θ may be calculated with a low calculation amount. Meanwhile, by the user, the threshold value θ may be calculated in advance and set in the smart gateway 700.

Smart gateway 700 is the probability of RSS change approximated by Equation 4 (

) And the threshold value (θ) to determine whether the intruder invaded (S350). The smart gateway 700 can determine the RSS change probability (

Is larger than the threshold value?, It is determined that an intrusion has occurred.

And the smart gateway 700 is the RSS change probability (

If) is equal to or smaller than the threshold value θ, it is determined that no intrusion has occurred and the step S310 is performed (S350, S310). This is expressed mathematically as shown in Equation 5 below.

Equation 5

When the smart gateway 700 determines that the intruder has intruded in step S350, the smart gateway 700 generates an intrusion alarm, and transmits the intrusion alarm to the control server 600 (S260 and S270). Here, the smart gateway 700 transmits the intrusion alarm to the gateway 500, and the gateway 500 transmits the intrusion alarm to the control server 600. The intrusion information transmitted to the control server 600, the control agent finally confirms, the control agent may dispatch to confirm the site situation or contact the police.

4 is a diagram illustrating an intrusion detecting apparatus 1000 that determines whether an intrusion is made through a received signal strength according to an exemplary embodiment of the present invention. The device 1000 of FIG. 4 corresponds to the terminal 400 of FIG. 1 or the smart gateway 700 of FIG. 2.

As shown in FIG. 4, the intrusion detecting apparatus 1000 according to an exemplary embodiment of the present invention includes an RF receiver 1100, an RSS measuring unit 1200, an RSS change value calculating unit 1300, a probability calculating unit 1400, And a threshold calculator 1500 and an intrusion determiner 1600.

The RF receiver 1100 receives a signal transmitted from each wireless device. Here, each wireless device corresponds to the base station 100 of FIG. 1, the WLAN AP 200, and the Bluetooth device 300, or the

ZigBee devices

800, 800 ′, 800 ″ of FIG. 2, and the WLAN device 900. Corresponds to).

The RSS measuring unit 1200 measures a received signal strength RSS for the signal received by the RF receiving unit 1100. The method of measuring the RSSI by the RSS measuring unit 1200 may be understood by those skilled in the art to which the present invention pertains, and thus a detailed description thereof will be omitted.

The RSS change value calculator 1300 calculates a received signal strength change value from the measured received signal strength (RSS) value. That is, the RSS change value calculator 1300 calculates the change value z as shown in Equation 2.

Next, the probability calculation unit 1400 uses the RSS change value z to determine the RSS change probability (

Calculate That is, the probability calculator 1400 calculates a simplified RSS change probability using the RSS change value as shown in Equation 4.

The threshold calculator 1500 calculates a threshold value [theta] used to determine whether an intruder enters. As described above, the threshold calculator 450 calculates a threshold value θ based on a desired misreport.

Intrusion determination unit 460 is the RSS change probability calculated by the probability calculation unit 440 (

) And the threshold value? Calculated by the threshold calculator 450 to determine whether an intruder is invading. That is, the intrusion determination unit 460 is the RSS change probability (

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

The present invention can be used in security systems.

Claims

A method for detecting an intruder by an intrusion detecting device that performs wireless communication with a first wireless device and a second wireless device, respectively,

Measuring a first received signal strength, which is an intensity of a signal received from the first wireless device,

Measuring a second received signal strength, the strength of the signal received from the second wireless device,

Calculating a change value of the received signal strength by using the first received signal strength and the second received signal strength;

Calculating a received signal strength change probability using the received signal strength change value, and

And comparing the probability of change of the received signal strength with a predetermined threshold to determine whether the intruder is invading.
The method of claim 1,

The intrusion detection device performs wireless communication with a third wireless device,

Measuring a third received signal strength, the strength of the signal received from the third wireless device,

The calculating of the received signal strength change value includes calculating the received signal strength change value using the first to third received signal strengths.
The method of claim 1,

The determining may include determining that the intruder is invading when the probability of change of the received signal strength is greater than the threshold.
The method of claim 1,

The received signal strength change value is a value obtained by subtracting an average value from the first received signal strength and the second received signal strength, respectively.
The method of claim 5,

The received signal strength change probability satisfies the following equation,

In the above equation, N is the total number of wireless devices including the first and second wireless devices, z is the received signal strength change value,
Represents the covariance of z
How to be.
The method of claim 1,

The calculating of the received signal strength change probability may include calculating the received signal strength change probability using a square of a change value of the received signal strength and a variance of the received signal strength.
The method of claim 1,

Wherein the first wireless device is a ZigBee device and the second wireless device is a wireless LAN device.
The method of claim 2,

The intrusion detection device is a smart gateway,

Wherein the first and third wireless devices are ZigBee devices and the second wireless devices are wireless LAN devices.
The method of claim 2,

The intrusion detection device is a terminal,

Wherein the first wireless device is a base station, the second wireless device is a WLAN AP, and the third wireless device is a Bluetooth device.
The method of claim 1,

If it is determined that the intruder intruded in the determining step, further comprising the step of transmitting an intrusion notification to the control server.
RF receiver for receiving signals transmitted from a plurality of wireless devices,

Received signal strength measuring unit for measuring the received signal strength that is the strength of the received signal,

A received signal strength change value calculator for calculating a received signal strength change value using the measured received signal strengths;

A probability calculator which calculates a probability of change of a received signal strength using the received signal intensity change value, and

An intrusion detection unit for determining the intruder by comparing the probability of change of the received signal strength with a predetermined threshold value.
The method of claim 11,

And the intrusion determining unit determines that the intruder intrudes when the probability of change of the received signal strength is greater than the threshold value.
The method of claim 11,

And the received signal strength change value calculating unit calculates the received signal strength change value by subtracting an average value from each of the measured received signal strengths.
The method of claim 13,

The received signal strength change probability satisfies the following equation,

In the above equation, N is the total number of wireless devices including the first and second wireless devices, z is the received signal strength change value,
Represents the covariance of z
Intrusion detection device.
The method of claim 11,

The probability of change in the received signal strength corresponds to the square of the change in the received signal strength and the dispersion of the measured received signal strength.
The method of claim 11,

The plurality of wireless devices includes a ZigBee device and a wireless LAN device.
The method of claim 11,

The plurality of wireless devices include a base station, a wireless LAN AP, and a Bluetooth device.
The method of claim 11,

The intrusion detection device is an intrusion detection device is a smart gateway.
The method of claim 11,

The intrusion detection device is a terminal intrusion detection device.