JP2012178059A - Crime-prevention system and crime-prevention program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crime-prevention system and a crime-prevention program for more easily monitoring a burglary operation without worrying about the dead angle of a camera.SOLUTION: This crime-prevention system includes: a plurality of radio communication terminal devices 2 which have acceleration sensors (vibration detection parts) 5 each arranged at a branch of a tree for detecting the vibration quantity of the branch and communication parts 6 having relay functions for configuring an ad hoc network N with each other for transmitting/receiving the vibration quantity; and a determination device 3 which has an arithmetic part 7 for processing the received vibration quantity and a determination part 8 for determining whether the occurrence of acceleration generated at the branch is caused by an artificial operation or a natural state by comparing the scale of the worked vibration quantity with that of a predetermined threshold relating to this vibration quantity.

Description

  The present invention relates to a fruit crime prevention system and a crime prevention program in an orchard.

  In orchards, fruit theft may be performed for the purpose of resale after the time when the fruit is sold. In view of the magnitude of damage in orchards, there is a need to prevent such criminal acts. Therefore, a crime prevention system that monitors the orchard using a plurality of cameras has been proposed (see Non-Patent Document 1, for example).

Fukatsu Tokihiro, Hirato Masayuki, “Development of Field Server for Monitoring”, Agricultural Information Research, 12 (1), pp, 1-12, 2003

  However, in the above conventional crime prevention system, there are many blind spots in the orchard with many leaves, and normal cameras cannot check at night. End up. In addition, it is necessary to always drive the camera to acquire image data, and data processing becomes enormous.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a crime prevention system and a crime prevention program that can more easily monitor a theft operation without worrying about blind spots of a camera.

The present invention employs the following means in order to solve the above problems.
A crime prevention system according to the present invention includes a vibration detection unit that is arranged on a tree branch and detects a vibration amount of the branch, and a communication unit that has a relay function for mutually configuring an ad hoc network and transmits and receives the vibration amount A plurality of wireless communication terminal devices, a calculation unit that processes the received vibration amount, and a cause of vibration generation of the branch by comparing the processed vibration amount with a predetermined threshold value related to the vibration amount And a determination unit that determines whether or not an artificial motion or a natural state is included.

  According to the present invention, by detecting the vibration amount of a tree branch and analyzing its characteristics, it is possible to determine whether the vibration of the branch is a vibration caused by a natural state or a vibration caused by an artificial action. Moreover, since the vibration amount is transmitted and received through an ad hoc network, it can be installed in a mountainous field.

  The crime prevention system according to the present invention is the crime prevention system, wherein the vibration amount is acceleration, and the calculation unit calculates a power spectrum density of the magnitude of the acceleration.

  According to the present invention, since the determination is based on the information on the magnitude of acceleration when the branch is shaken, it is possible to appropriately discriminate whether the vibration is caused by a natural state or the vibration caused by an artificial action even with a simple configuration.

  The crime prevention system according to the present invention is the crime prevention system, wherein the threshold is set for the power spectral density in a frequency band of 3 Hz or more.

  According to the present invention, since the comparison determination is performed in a range with a small error, it is possible to more suitably identify whether the vibration is caused by a natural state or the vibration caused by an artificial operation.

  The crime prevention system according to the present invention is the crime prevention system, wherein the vibration amount is acceleration, the threshold is a first threshold relating to the magnitude of the acceleration, and the magnitude of acceleration in a set period is the first threshold. A second threshold value regarding an occurrence time interval of acceleration exceeding a threshold value and a frequency thereof, wherein the calculation unit exceeds the first threshold value in the set period, and a first calculation unit that calculates the magnitude of the acceleration. A second calculation unit that calculates the generation time interval of the magnitude acceleration and the frequency of the acceleration, and the determination unit compares the magnitude of the acceleration with the first threshold value, And a second determination unit that compares the generation time interval of the acceleration exceeding the first threshold and the generation frequency with the second threshold.

  According to the present invention, it is possible to make a comparative determination based on the occurrence frequency of acceleration exceeding a predetermined magnitude, and it is possible to more suitably identify whether the vibration is caused by a natural state or vibration caused by an artificial action.

  The crime prevention system according to the present invention is the crime prevention system, wherein the vibration detection unit is arranged in the vicinity of a branching portion to the side branch in the sub-main branch.

  According to the present invention, it is possible to improve the reliability by reducing an error when determining whether the vibration is caused by a natural state or vibration caused by an artificial operation.

  According to the present invention, a fruit theft operation can be detected without worrying about the blind spot of the camera even in an orchard where trees and leaves are dense or at night.

It is a functional block diagram which shows the crime prevention system which concerns on the 1st Embodiment of this invention. It is a functional block diagram which shows the crime prevention system which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the use condition of the crime prevention system which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the use condition of the crime prevention system which concerns on the 1st Embodiment of this invention. It is a graph which shows the magnitude | size of the acceleration which generate | occur | produces in a branch, when it cuts out from the state which hung one simulated fruit on the branch in the crime prevention system which concerns on the 1st Embodiment of this invention. It is a graph which shows the magnitude | size of the acceleration which generate | occur | produces in a branch when it cuts out from the state which suspended three simulated fruits on the branch in the crime prevention system which concerns on the 1st Embodiment of this invention. It is a graph which shows the magnitude | size of the acceleration which generate | occur | produces in a branch when it cuts out from the state which suspended five simulated fruits in the branch in the crime prevention system which concerns on the 1st Embodiment of this invention. It is a graph which shows the power spectrum density of the magnitude | size of the acceleration which generate | occur | produces in a branch at the time of a natural state in the crime prevention system which concerns on the 1st Embodiment of this invention. It is a graph which shows the power spectrum density of the frequency band exceeding 3 Hz in FIG. It is a graph which shows the power spectrum density of the magnitude | size of the acceleration which generate | occur | produces in a branch, when a simulated fruit is cut out by the crime prevention system which concerns on the 1st Embodiment of this invention. It is a graph which shows the power spectrum density of the frequency band exceeding 3 Hz in FIG. It is a graph which shows the magnitude | size of the acceleration which generate | occur | produces in a branch, when it cuts out from the state which suspended five simulated fruits in the branch in the crime prevention system which concerns on the 2nd Embodiment of this invention. It is a graph which shows the magnitude | size of the acceleration which generate | occur | produces in a branch at the time of a natural state in the crime prevention system which concerns on the 2nd Embodiment of this invention. It is a graph which shows the magnitude | size of the acceleration which generate | occur | produces in a branch at the time of a natural state in the crime prevention system which concerns on the 2nd Embodiment of this invention. It is a graph which shows the frequency by which the acceleration exceeding 1020-1100 mG was detected in 20 seconds in the crime prevention system which concerns on the 2nd Embodiment of this invention. When the crime prevention system according to the second embodiment of the present invention cuts out five simulated fruits from a state where they are hung on a branch, the time interval and the frequency at which acceleration exceeding the first threshold occurs in 20 seconds are shown. It is a graph. It is a graph which shows the time interval which the acceleration exceeding a 1st threshold value generate | occur | produced in 20 seconds, and its frequency in the natural state in the crime prevention system which concerns on the 2nd Embodiment of this invention.

(First embodiment)
A first embodiment according to the present invention will be described with reference to FIG.
As shown in FIG. 1, the crime prevention system 1 according to this embodiment includes a wireless communication terminal device 2 and a determination device 3. Both are connected to each other via the wireless Internet W.

  A plurality of wireless communication terminal devices 2 are arranged on a plurality of tree branches such as fruit trees, and an acceleration sensor (vibration detection unit) 5 that detects acceleration (vibration amount) at the time of vibration of the branches, and an ad hoc network N are mutually connected. Each of the communication units 6 has a relay function for configuring and transmits / receives acceleration data detected by the acceleration sensor 5.

  The determination device 3 includes a ROM (read only memory) (not shown) in which programs and data for performing necessary processing as a computer are stored, and a RAM (random access) (not shown) for temporarily storing data relating to acceleration. Memory), a CPU (Central Processing Unit) (not shown) that performs processing according to the crime prevention program P1 stored in the ROM or the like.

  The crime prevention program P1 includes a calculation unit 7 and a determination unit 8 as functional means (program modules).

  The computing unit 7 calculates the power spectral density along with the magnitude of the acceleration of the branch where the wireless communication terminal device 2 is arranged, from the acceleration data transmitted by the communication unit 6.

  The determination unit 8 compares the calculated power spectral density with a predetermined threshold related thereto, and determines that the cause of the acceleration is an artificial action when the magnitude exceeds the threshold, and is equal to or less than the threshold. In this case, it is determined that the cause of the acceleration is a natural state due to wind or the like.

Next, the crime prevention method by the crime prevention system 1 which concerns on this embodiment is demonstrated.
First, the wireless communication terminal device 2 is installed on a plurality of tree branches. Then, an ad hoc network N is formed between the communication units 6 of the wireless communication terminal devices 2.

  The communication unit 6 transmits the branch acceleration data acquired by the acceleration sensor 5 at a predetermined sampling cycle to the calculation unit 7 of the determination device 3 via the ad hoc network N. And in the determination apparatus 3, the calculating part 7 calculates the power spectrum density with the magnitude | size of an acceleration.

  And the determination part 8 compares with a threshold value, and when the acceleration which generate | occur | produced in the branch exceeds a predetermined threshold value, it determines with artificial motions, such as theft of fruits etc. having occurred. On the other hand, if it is less than or equal to the predetermined threshold, it is determined that the object vibrates due to a natural state such as wind.

  According to the security system 1 and the security program P1, by detecting the acceleration of a tree branch and analyzing the characteristics of the tree branch, it is possible to determine whether the branch shake is a vibration caused by a natural state or an artificial action. In addition, since the acceleration data is transmitted to and received from the plurality of wireless communication terminal devices 2 via the ad hoc network N and transmitted to the determination device 3, it can also be installed in a mountainous field.

  Therefore, it is possible to detect a fruit theft operation without worrying about the blind spot of the camera even in an orchard where trees and leaves are dense or at night.

(Second Embodiment)
Next, a second embodiment will be described.
In addition, the same code | symbol is attached | subjected to the component similar to 1st Embodiment mentioned above, and description is abbreviate | omitted.
The difference between the second embodiment and the first embodiment is that, as shown in FIG. 2, in the crime prevention system 10 and the crime prevention program P2 according to this embodiment, the calculation unit 12 of the determination device 11 performs the first calculation. 12A and 12B, and the determination unit 13 includes a first determination unit 13A and a second determination unit 13B.

  The threshold value in this case includes a first threshold value relating to the magnitude of acceleration, and a second threshold value relating to the generation time interval and frequency of acceleration in which the magnitude of acceleration in the set period exceeds the first threshold value. The first calculation unit 12A calculates the magnitude of acceleration. The second calculation unit 12B calculates the generation time interval and the generation frequency of acceleration having a magnitude exceeding the first threshold in the set period. The first determination unit 13A compares the magnitude of the acceleration with the first threshold value. The second determination unit 13B compares the generation time interval of the acceleration exceeding the first threshold and the generation frequency with the second threshold.

Next, the crime prevention method by the crime prevention system 10 which concerns on this embodiment is demonstrated.
First, similarly to the first embodiment, the wireless communication terminal device 2 is installed, and an ad hoc network N is formed between the communication units 6 of the wireless communication terminal device 2.

  The communication unit 6 transmits the branch acceleration data acquired by the acceleration sensor 5 at a predetermined sampling cycle to the calculation unit 12 of the determination device 11 via the ad hoc network N. Then, in the determination device 11, the first calculation unit 12A calculates the magnitude of acceleration.

  The first determination unit 13A compares the calculated acceleration magnitude with a first threshold value. Then, the time when the acceleration exceeding the first threshold value is generated is stored in a RAM (not shown) or the like.

  The second computing unit 12B calculates the time interval when the stored acceleration magnitude exceeds the first threshold. And the 2nd determination part 13B determines with it being artificial operation | movement, such as theft, when the acceleration of the magnitude | size exceeding a 1st threshold value generate | occur | produces in the time interval less than a 2nd threshold value within a setting period.

  According to the crime prevention system 10 and the crime prevention program P2, it is possible to distinguish between a natural state and an artificial action as in the first embodiment. At this time, since the determination is made based on the time interval, the determination can be made more suitably.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, although acceleration is used as the vibration amount, the present invention is not limited to this, and any vibration can be used as long as it can be detected by a sensor.

Example 1
In the crime prevention system 1 according to the first embodiment of the present invention, as shown in FIG. 3, a simulated fruit D is used instead of the actual fruit because a plurality of fruits may be stolen when considering theft of fruits. In the state where the weight was hung on the branch of the tree, the identification between the human movement and the natural state was carried out. Hitachi wireless-T3-axis acceleration sensor was used as the wireless communication terminal device 2 and was arranged in the vicinity of the branching portion of the tree branch to the side branch in the sub-main branch. The sampling frequency was 50 Hz.

  First, obtain acceleration data when nothing is done (natural state) and when 1, 3, 5 and 5 simulated fruits D are hung from the branches, respectively (at the time of artificial movement) did. The data at this time is transmitted to the determination device 11 via the ad hoc network N formed between the wireless communication terminal devices 2 as shown in FIG. Thus, a state in which the acceleration increased when the simulated fruit D was cut was detected. FIG. 5 shows the acquisition results for one case, FIG. 6 shows the acquisition results for three cases, and FIG. 7 shows the acquisition results for five cases. In the figure, acceleration is displayed using a norm that is not constrained by the sensor axis.

  Then, a fast Fourier transform was performed on the acquired acceleration magnitude, and a power spectral density was calculated. An example of the result in the natural state is shown in FIG. 8 (FIG. 9 shows an extracted frequency band after 3 Hz). Moreover, the example of the result at the time of cutting of the simulated fruit D is shown in FIG. 10 (what extracted the frequency band after 3 Hz is shown in FIG. 11). When FIG. 9 and FIG. 11 are compared, there is a particular difference in the frequency band after 3 Hz. Therefore, the threshold value is set in the frequency band after 3 Hz to identify the natural state and the artificial action. When the distance between the acceleration sensor and the simulated fruit D was changed with this threshold, the reproducibility could be 90% or more within 2 m. In addition, the frequency band in the threshold setting is not necessarily 3 Hz or higher, and may be appropriately changed according to the calculation result.

(Example 2)
Next, in the crime prevention system 10 according to the second embodiment of the present invention, identification confirmation between an artificial action and a natural state was performed in the same manner as in Example 1. The wireless communication terminal device 2 used was the same as described above.

  First, the magnitude of the acceleration when five simulated fruits D are cut out is shown in FIG. Moreover, the magnitude | size of the acceleration at the time of a strong wind although it is a natural state is each shown in FIG. 13, FIG. And in order to obtain | require a 1st threshold value, the frequency by which the acceleration exceeding 1020-1100 mG was detected in 20 seconds was calculated. The results are shown in FIG.

  Here, for example, if the first threshold value is 1030 mG, about 11% is equal to or higher than the first threshold value when the simulated fruit D is cut, but it is only about 3% in a natural state even in a strong wind. Further, when the first threshold value is 1040 mG, about 4% is equal to or higher than the first threshold at the time of cutting, whereas it is 0% at the time of strong wind. In other words, it was found that if the magnitude of acceleration during this period is set as the first threshold value, the artificial movement can be identified with a high probability.

  Based on this, when the first threshold was set to 1030 mG, the frequency of the time interval at which acceleration exceeding this magnitude occurred in 20 seconds was calculated in order to obtain the second threshold. FIGS. 16 and 17 show the time intervals and the frequencies when the five simulated fruits D are cut out and when the wind is strong. When both were compared, it was found that there was a significant difference in frequency in the region where the time interval was short. In other words, it has been found that by setting the second threshold value in the area, it is possible to appropriately identify the human action.

DESCRIPTION OF SYMBOLS 1,10 Crime prevention system 2 Wireless communication terminal device 3,11 Judgment device 5 Acceleration sensor (vibration detection part)
6 Communication unit 7, 12 Calculation unit 8, 13 Determination unit 12A First calculation unit 12B Second calculation unit 13A First determination unit 13B Second determination unit P1, P2 Security program

Claims (6)

A plurality of wireless communication units including a vibration detection unit that is arranged on a tree branch and detects a vibration amount of the branch, and a communication unit that has a relay function for mutually configuring an ad hoc network and transmits and receives the vibration amount A terminal device;
A calculation unit that processes the received vibration amount, and a determination unit that determines whether the vibration generation cause of the branch is an artificial operation or a natural state by comparing the processed vibration amount with a predetermined threshold relating to the vibration amount And a determination device having
A security system characterized by comprising The amount of vibration is acceleration,
The crime prevention system according to claim 1, wherein the calculation unit calculates a power spectrum density corresponding to the magnitude of the acceleration.   The crime prevention system according to claim 2, wherein the threshold is set for the power spectral density in a frequency band of 3 Hz or more. The amount of vibration is acceleration,
The threshold is a first threshold for the magnitude of the acceleration;
A second threshold value regarding an occurrence time interval of acceleration in which the magnitude of acceleration in the set period exceeds the first threshold value and the frequency thereof;
With
A first calculator that calculates the magnitude of the acceleration;
A second calculation unit that calculates an occurrence time interval and an occurrence frequency of acceleration having a magnitude exceeding the first threshold in the set period;
With
A first determination unit that compares the magnitude of the acceleration with the first threshold;
A second determination unit that compares the generation time interval of the acceleration exceeding the first threshold and the generation frequency thereof with the second threshold;
The crime prevention system according to claim 1, further comprising:   The crime prevention system according to any one of claims 1 to 4, wherein the vibration detection unit is arranged in the vicinity of a branching portion to the side branch in the sub-main branch. A security program for causing a computer to function as the determination device according to any one of claims 1 to 5.

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