JP2020187131A - Intrusion detection sensor - Google Patents

Abstract

To provide an intrusion detection sensor capable of reliably detecting an intruder while preventing a decrease in detection sensitivity of an adjacent electric field.SOLUTION: An intrusion detection sensor 1 has multiple detection lines 10 neighboring to each other excluding a corner of the monitoring area E in which the distance between the end portions on the segment boundary side of the respective detection lines 10 is set to a width through which at least person cannot pass. A non-conductive cable 32 substantially nonconductive and non-stretchable are used as the tension member 30. With this, the detection sensitivity is prevented from degrading at the segment boundaries between sensors and intruders can be reliably detected.SELECTED DRAWING: Figure 2

Description

The present invention relates to an intrusion detection sensor that is laid on the outer periphery of a monitoring area to be monitored and detects an intruder in the area.

When monitoring a large site such as a large-scale plant that serves as a monitoring area, for example, a surveillance camera, a vibration sensor, or the like, in order to detect an intruder that invades through a structure such as a fence provided along the outer periphery thereof. Various detection sensors such as ultrasonic sensors and infrared sensors are used.

However, the detection accuracy of the surveillance camera may decrease due to the weather such as fog and rain.
The vibration sensor has a problem that the fence on which the sensor is installed vibrates due to the influence of wind and malfunctions.
The ultrasonic sensor has a problem that erroneous detection is likely to occur due to the movement of branches and leaves of trees due to the wind and small animals.
Since the infrared sensor needs to form the detection area from the light emitting part to the light receiving part in a straight line, when the fence on which the sensor is installed has a curved surface structure, the detection area cannot be formed along the curved surface of the fence. .. If it is installed, a plurality of sensors must be arranged along a curved surface, which causes a problem that the installation cost increases and the system configuration becomes complicated.

In addition, none of the sensors detects a human body close to the structure from the inside of the monitoring area, and it is difficult to pinch the detection area so as to detect only an intruder approaching from the outside of the monitoring area. .. Therefore, in order to be able to detect a vast monitoring area with high accuracy, a large number of sensors are required, and there is a problem that the installation cost is increased.

From the above, for example, the following sensors can accurately detect only the proximity of intruders from outside the surveillance area without being affected by the shape and weather of the surveillance area, and can evenly monitor the vast surveillance area. A laying type electric field sensor as disclosed in Patent Document 1 is preferably used.

Japanese Unexamined Patent Publication No. 2001-153964

By the way, in the conventional laying type electric field sensor, a sensor cable that generates an electric field by applying an AC signal of a predetermined frequency, a support member that supports the sensor cable outside the monitoring area, and a change in the electric field generated by the sensor cable. It is composed of a controller (not shown) that detects the presence or absence of an intruder, and is laid along the outer periphery of the monitoring area as shown in FIG. 6, for example.

In addition, when monitoring a vast monitoring area, it is not possible to determine from which location the electric field sensors have entered, so multiple electric field sensors are laid along the outer circumference of the monitoring area at predetermined intervals (for example, at intervals of 40m to 80m). To do. Then, a part of the sensor cable is overlapped so that the adjacent electric field regions partially overlap each other so that there is no gap between the sensors.

By the way, in this type of electric field sensor, a sensor cable is locked to the tip of a support member extending from a fence pole toward the outside of the monitoring area, and metal wires are connected to both ends of the sensor cable to provide a predetermined tension. It is stretched in a state where it is hung.

However, since the oscillation frequencies of adjacent detection lines are different, overlapping a part of the adjacent electric field sensors interferes with each other and lowers the electric field strength, which in turn lowers the detection sensitivity of the sensor overlapping portion. There is a problem of doing it.

In addition, at the corners of the monitoring area, different electric field sensors are laid from two directions toward the corners, and the sensor cables on the corners of both sensors are stretched in a state of being crossed near the corners. There is.

However, when laid in this way, there is a problem that the electric field strength is lowered due to mutual interference at the intersecting portions of the sensor cables, and the detection sensitivity of the sensor overlapping portion is lowered due to the influence.

The present invention has been made in view of such a problem, and when laying a plurality of sets of electric field sensors adjacent to each other around a monitoring area, the present invention reliably suppresses a decrease in detection sensitivity of adjacent electric fields. It is an object of the present invention to provide an intrusion detection sensor capable of detecting an intruder.

The first aspect according to the present invention is
In an intrusion detection sensor in which a corner portion of the monitoring area is formed by a first fence and a second fence surrounding the outer periphery of the monitoring area and an intruder near the monitoring area is detected.
A detection line that generates an electric field with an applied AC signal and outputs a detection signal according to the change in the electric field.
A support member that supports the detection line in a substantially horizontal direction along the fence at a position separated from the fence surface by a predetermined distance outside the monitoring area.
An insulating member is connected to one end of a non-conductive cable having substantially no conductivity and elasticity, a tension adjusting member is connected to the other end of the cable, and the detection line is connected via the insulating member. And the tensioning member to be stretched with a predetermined tension applied to the
With
The first detection line stretched along the first fence is stretched at a position where the corner side end is aligned with the fence surface of the second fence.
The second detection line stretched along the second fence is located on the corner side of the first detection line when the corner side end is viewed in a plan view of the monitoring area. It is an intrusion detection sensor characterized in that it intersects an extension line extending from an end position and is stretched at a position exceeding a predetermined length from the intersection of both lines.

A second aspect of the present invention is the intrusion detection sensor according to the first aspect.
The second detection line is characterized in that it extends from the intersection to a length that can be detected by an intruder who has entered through the gap between the first detection line and the second detection line. It is an intrusion detection sensor.

A third aspect of the present invention is the intrusion detection sensor according to the first aspect or the intrusion detection sensor according to the second aspect.
It is provided in units of sections divided into a plurality of sections along the first fence and the second fence.
The detection lines of the intrusion detection sensors adjacent to each other other than the corners of the monitoring area shall be stretched with the distance between the ends on the section boundary side of each detection line set to at least a width that does not allow people to pass through. It is an intrusion detection sensor characterized by.

According to the present invention, at the corner of the monitoring area, the end position on the corner side of the first detection line is set to the position aligned with the fence surface of the second fence, and the end position on the corner side of the second detection line is set. The termination position intersects the extension line extending from the corner-side end of the first detection line laid along the first fence when the surveillance area is viewed in a plan view, and further from this intersection. By extending to a position exceeding a predetermined length, the electric fields do not interfere with each other between the first detection line and the second detection line, the electric field strength does not decrease, and an intruder is reliably detected. can do.

Further, the length of extending the second detection line from the intersection of the extension line extended from the first detection line and the second detection line is the length of the first detection line and the second detection line at the corner. By extending the distance between the two to the extent that an intruder who has invaded can be detected, an intruder who cannot be detected by the first detection line can be detected by the extension portion of the second detection line.

Further, the detection lines of the intrusion detection sensors adjacent to each other other than the corners of the monitoring area are adjacent to each other by extending the distance between the ends of the detection lines on the section boundary side at least at intervals that people cannot pass through. Since the electric fields generated by the adjacent detection lines do not interfere with each other at the section boundary of the intrusion detection sensor, the intruder can be reliably detected without lowering the detection sensitivity. Further, since the distance between the ends of each detection line at the section boundary is set to the distance that people cannot pass through, there is no possibility of intrusion through this gap.

Further, since a non-conductive cable having substantially no conductivity and elasticity is used as the stretching member 30 for stretching the detection line, the electric field strength is increased at the section boundary of the detection line of the adjacent intrusion detection sensor. An intruder can be reliably detected at the section boundary between the sensors without deterioration.

It is the schematic which shows the human body detection principle of the intrusion detection sensor which concerns on this invention. It is the schematic which shows an example of the laying form of the sensor. It is a schematic block diagram which shows the structure of each part which constitutes the sensor. It is a schematic block diagram which shows the state when the sensor is laid in the straight part of the monitoring area. It is a schematic block diagram which shows the state when the sensor is laid in the corner part of the monitoring area. It is a schematic block diagram which shows the laying example of the conventional electric field sensor.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the attached drawings.

The drawings attached to this specification may be represented schematically by changing the scale, aspect ratio, shape, etc. from the actual product for convenience of illustration and comprehension. However, it does not limit the interpretation of the present invention. Therefore, the present invention is not limited by the embodiments described with reference to the attached drawings, and all other embodiments, examples, operational techniques, and the like that can be considered by those skilled in the art based on this embodiment are the present invention. It shall be included in the category of.

In addition, in the following description with reference to the accompanying figures in the present specification, when the words up, down, left, and right are used to indicate a direction or position, this means that the user shows each figure as illustrated. It matches the top, bottom, left, and right when viewed in.

[1. Operation principle of intrusion detection sensor]
First, the operating principle of intrusion detection by the intrusion detection sensor 1 of the present invention will be described.
As shown in FIG. 1, the detection line 10 is a set of the oscillation line 11 and the detection line 12, and one or a plurality of detection lines 10 are installed according to the height of the fence 50. In the illustrated example, the fence 50 is a protective fence having a stealth, and two sets of upper and lower detection lines 10 are laid between the ground on the fence surface and the base end portion of the stealth. Further, the oscillation line 11 and the detection line 12 of each set are connected to the controller 40 corresponding to the detection line 10, respectively.

The controller 40 applies an AC signal having a predetermined oscillation frequency (for example, sinusoidal AC) to the oscillation line 11 to generate an electric field with the sensing line 12. When an intruder approaches the generated electric field, the electric field changes, and a detection signal corresponding to this change is output to the controller 40 via the sensing line 12. Then, when the controller 40 inputs the AC signal after the electric field change received by the sensing line 12, the controller 40 performs predetermined signal processing (filter processing, amplification processing, etc.) on the signal, and then analyzes the signal to analyze the intruder. Determine the presence or absence.

In FIG. 1, two sets of detection lines 10 are laid along the outer surface of the fence 50, the upper detection line 10 is the detection line 12 and the oscillation line 11 in order from the top, and the lower detection line 10 is in order from the top. An example of laying as an oscillation line 11 and a sensing line 12 is shown. However, the laying positions of the oscillation line 11 and the detection line 12 constituting the detection line 10 in the vertical direction are not particularly limited, and for example, the vertical positions of the lines in the drawing may be reversed, or the lower direction shown in FIG. The arrangement of the detection lines 10 of the above may be adopted as it is for the upper detection line 10.

[2. Intrusion detection sensor configuration]
Next, the configuration of the intrusion detection sensor 1 according to the present invention will be described with reference to FIGS. 2 or 3.
As shown in FIG. 2, the intrusion detection sensor 1 of the present embodiment is divided into a plurality of sections along a fence 50 which is a structure provided so as to surround the outer periphery of the monitoring area E to be monitored. It will be laid.

The intrusion detection sensor 1 includes a detection line 10 that generates an electric field for detecting an intruder, and a fence surface 51 outside the monitoring area E in the fence 50 (hereinafter, this surface is also referred to as an “outer surface 51”). Based on the support member 20 that supports in a substantially horizontal direction at a position separated from the detection line 20, the tension member 30 that stretches the detection line 10 supported by the support member 20, and the change in the electric field generated around the detection line 10. The controller 40 is provided to determine the presence or absence of an intruder in the vicinity of the monitoring area E.

<2-1. Detection line>
The detection line 10 has a configuration in which an oscillation line 11 and a detection line 12, which are conductive lines, are paired. Insulating members 31, which will be described later, are connected to both ends (terminations) of the oscillating line 11 and the sensing line 12, respectively, and two lines are laid in a substantially horizontal direction along the outer surface 51 of the fence 50 by the supporting member 20. The arrangement of the oscillation line 11 and the detection line 12 constituting the detection line 10 in the vertical direction (vertical direction) is not particularly limited.

Further, a part of the oscillation line 11 and the sensing line 12 is connected to the controller 40. The oscillating line 11 generates an electric field with the sensing line 12 when an AC signal having a predetermined transmission frequency is applied from the controller 40. Further, the sensing line 12 outputs a signal (detection signal) indicating a change in the electric field based on the proximity of the intruder to the controller 40.

The area of the monitoring area E where the intrusion detection sensor 1 is laid is vast, and it is necessary to know in which area the intrusion occurred when there was an intruder. Therefore, the detection lines 10 are set to, for example, 40 m to 80 m per section, and a plurality of detection lines 10 are laid between the ends of the detection lines 10 at the boundary of adjacent sections at intervals (width) so that an intruder cannot enter. Further, since the electric field strength of the detection line 10 weakens when the distance to the ground is short, it is preferable to lay the detection line 10 at least above a predetermined distance (for example, about 20 cm to 30) from the ground.

Further, as shown in FIG. 1, for example, by arranging a plurality of sets of detection lines 10 in the vertical direction according to the height of the fence 50, a human body can be detected in the laying section of the intrusion detection sensor 1. A plurality of electric fields are formed, and an intruder can be detected with higher accuracy.

<2-2. Support member>
The support member 20 is composed of an arm 21 and a mounting member 22, and supports the oscillation line 11 and the sensing line 12 so as to be laid in a substantially horizontal direction along the outer surface 51 of the fence 50, respectively.

The arm 21 is a tip portion made of resin (ABS) having a locking groove in which the detection line 10 is locked, and the main body is a member made of FRP. When the detection lines 10 are laid, a plurality of arms 21 are used at predetermined intervals within one section in order to maintain the state in which the lines 11 and 12 are pulled by a predetermined tension.

Although it depends on the spatial size of the electric field generated by the detection line 10 (that is, the voltage value of the AC signal), it is determined from the fence 50, for example, from the viewpoint of suppressing the influence of the fence 50 as much as possible and ensuring a constant detection sensitivity. It is preferable to lay them at positions separated by a distance (for example, about 50 cm). Therefore, the arm 21 also has a length that matches the separation distance.

The mounting member 22 is a stainless steel (for example, SUS304) mounting bracket (U-shaped bracket, mounting plate, etc.) having excellent weather resistance and mechanical strength. The mounting member 22 is installed by screwing it to the support column 60 (in this example, the fence pole of the fence 50) while supporting the base end portion of the arm 21.

<2-3. Upholstery member>
The tensioning member 30 is composed of an insulating member 31, a non-conductive cable 32, and a tension adjusting member 33, and a predetermined tension is applied to a detection line 10 laid via the support member 20. It is a member for tensioning. As a result, the detection line 10 is stretched in a substantially horizontal direction without hanging between the arms 21.

The insulating member 31 is an insulator made of a material (for example, ceramics, glass, synthetic resin) having excellent insulation, weather resistance, and mechanical strength. One end of the insulating member 31 is connected to the end of the detection line 10 (oscillation line 11 or detection line 12), and the other end is connected to the non-conductive cable 32.

The non-conductive cable 32 is a non-metallic wire rod having substantially no conductivity and elasticity, such as a devegrass rope. The non-conductive cable 32 is used by tightening both ends with, for example, a double fisherman's knot to form a ring shape, and a thimble 32a is attached to a connecting portion with another member. The thimble 32a is an annular member made of stainless steel (for example, SUS304) having excellent weather resistance and mechanical strength, and is mounted in a state where a part of the non-conductive cable 32 is wound.

In the present embodiment, as shown in FIG. 3, among the non-conductive cables 32, the cable interposed between the detection line 10 and the tension adjusting member 33 is designated as the first non-conductive cable 32b, and a part thereof. Is connected to the insulating member 31, and the other portion is connected to the tension adjusting member 33 via the thimble 32a. A part of the second non-conductive cable 32c interposed between the support column 60 and the tension adjusting member 33 is wound around the support column 60, and the other part is connected to the tension adjusting member 33 via the thimble 32a. Be connected. It is not necessary to use two non-conductive cables 32 as described above. For example, the tension adjusting member 33 may be directly connected to the support column 60, and only the first non-conductive cable 32b may be used. ..

The tension adjusting member 33 is composed of a turnbuckle 33a and an elastic member 33b, and is a member for adjusting the tension of the detection line 10. The tension adjusting member 33 is not limited to the configuration including the turnbuckle 33a and the elastic member 33b, and is not particularly limited as long as the tension of the detection line 10 can be adjusted.

The turnbuckle 33a is made of stainless steel (for example, SUS304) having excellent weather resistance and mechanical strength, one end of which is connected to the first non-conductive cable 32b via a thimble 32a, and the other end of which is connected to an elastic member 33b. It is used when adjusting the tension when the detection line 10 is stretched.

The elastic member 33b is a member such as a coil spring that is elastically deformed to apply a predetermined tension. One end of the elastic member 33b is connected to the turnbuckle 33a, and the other end is connected to a second non-conductive cable 32c wound around a support 60 (for example, a fence pole of a fence 50).

<2-4. Controller>
The controller 40 is configured by appropriately combining a processor such as a CPU (Central Processing Unit), memory (ROM, RAM, etc.), hardware such as other electronic circuits, or software such as a program having that function. .. The controller 40 is provided for each intrusion detection sensor 1 that is laid in a plurality of sections divided along the outer circumference of the monitoring area E.

The controller 40 applies an AC signal (for example, a sinusoidal AC) that oscillates at a predetermined oscillation frequency to the oscillation line 11 in order to detect an intruder close to the intrusion detection sensor 1, and the applied AC signal is used. A detection signal corresponding to the change in the generated electric current is input via the sensing line 12. Further, when the detection signal is input from the sensing line 12, the controller 40 performs predetermined signal processing (specifically, filtering processing and amplification processing on the input detection signal, etc.) on the signal, and then signals. Analysis processing (specifically, phase inversion processing of the detection signal, superimposition processing of the AC signal and the detection signal after phase inversion, and a preset threshold value for the amount of change in the amplitude of the superposed signal waveform. (Comparison processing, etc.) is performed to determine the presence or absence of an intruder.

If it is determined that there is an intruder as a result of the determination, a signal indicating that there is an intruder is output to a monitoring device (installed in a monitoring center or the like) (not shown) by wireless or wired communication. As a result, the observer can immediately grasp in which section of the monitoring area E the intruder is detected by the output from the intrusion detection sensor 1.

<2-5. Fence>
The fence 50 is a structure installed along the outer circumference of the monitoring area E. In the present embodiment, a protective fence having a sneak back is adopted as the fence 50, but the present invention is not limited to this, as long as it separates the inside and outside of the monitoring area E, such as a fence that can prevent intruders from entering. Good.

<2-6. Prop ＞
A plurality of columns 60 are installed on the ground at predetermined intervals along the outer circumference of the monitoring area E, and are for attaching the support member 20 and the extension member 30. In this embodiment, the fence pole of the fence 50 is used as the support column 60. Further, when laying at the corner portion Ea of the monitoring area E, the support column 60 is provided at a position separated from the corner portion Ea by a predetermined distance (about 2 m to 4 m).

[3. How to lay intrusion detection sensor]
Next, the method of laying the intrusion detection sensor 1 described above will be described.
A plurality of intrusion detection sensors 1 of the present invention are laid so as to surround the periphery of the monitoring area E, and the laying method is different between the corner portion Ea of the monitoring area E and the portion other than the corner portion Ea (for example, a straight line portion). ..

Here, the corner portion Ea of the monitoring area E is a portion formed by abutting the side ends of the fence 50 installed so as to surround the outer periphery of the monitoring area E. In the present embodiment, as shown in FIG. 5, when the monitoring area E is viewed in a plane, the internal angle (the angle on the monitoring area E side) is substantially a right angle.

Hereinafter, a portion of the monitoring area E other than the corner portion Ea (here, a straight portion) and an installation method in the corner portion Ea will be described with reference to FIGS. 3 to 5, respectively. As a matter of course, since the detection line 10 is composed of the oscillation line 11 and the detection line 12, the oscillation line 11 and the detection line 12 constituting the detection line 10 to be laid according to the laying method shown below. Will be laid together.

<3-1. How to lay a straight part ＞
As shown in FIG. 3 or 4, the sensor installation method in the straight portion of the monitoring area E is such that the detection line 10 is laid substantially horizontally at a position at a predetermined height from the ground in accordance with the height of the fence 50. In addition, a plurality of arm trees 21 are arranged side by side at predetermined intervals using the mounting member 22 on the support column 60.

Next, the detection line 10 is locked to the tip of the arm 21 to temporarily install the detection line 10, and the tension member 30 is connected to each end (each end) of the detection line 10. That is, one end of the first non-conductive cable 32b is connected to the end of the detection line 10 via an insulating member 31, and the turnbuckle 33a is connected to the other end of the first non-conductive cable 32b. , The tension adjusting member 33 is connected in the order of the elastic member 33b. Further, the end portion of the elastic member 33b on the side not connected to the turnbuckle 33a and the end portion of the second non-conductive cable 32c wound around the support column 60 are connected.

Then, the tension is adjusted by the tension adjusting member 33 so that the detection line 10 is stretched with a predetermined tension, and the laying work of the detection line 10 is completed.

Further, the detection lines 10 of the intrusion detection sensors 1 adjacent to each other other than the corner Ea of the monitoring area E are each detection line 10 in order to obtain an electric field strength sufficient to detect an intruder without interfering with each other. The distance between the ends on the boundary side of the section is set at least at a distance (width) that people cannot pass through.

Here, the distance that a person cannot pass is a width that cannot be passed when an intruder invades the fence 50 in a frontal or sideways posture, and the electric fields generated by the adjacent detection lines 10 interfere with each other. There is no distance, for example, it is preferably about 15 cm to 30 cm, preferably about 20 to 25 cm.

As described above, in the intrusion detection sensor 1 of the present invention, when the detection line 10 is stretched, the non-conductive cable 32 which does not substantially have conductivity and elasticity is used as the stretching member 30. Intruders can be reliably detected at the section boundary between the sensors without reducing the electric field strength at the section boundary of the detection line 10 of the adjacent intrusion detection sensor 1.

Further, since the detection lines 10 do not intersect each other at the section boundary of the adjacent intrusion detection sensors 1, the electric fields of the adjacent sensors do not interfere with each other as in the conventional sensor. Therefore, the electric field strength does not decrease, and an intruder can be reliably detected even at the section boundary between the sensors. Further, since the distance between the ends of the detection lines 10 at the section boundary is a width that cannot be passed by a person, there is no concern that an intruder will enter through the gap between the adjacent detection lines 10.

<3-2. How to lay the corners>
As shown in FIG. 3 or 5, in the method of laying the sensor at the corner Ea of the monitoring area E, the first detection line 10a is laid along the fence surface 51a of the first fence 50a, and the corner Ea is laid. A second detection line 10b is laid along the fence surface 51b of the other fence (second fence 50b) to be configured. In the following description, the first detection line 10a and the second detection line 10b are described in this order, but the laying order may be reversed.

(Method of laying the first detection line)
First, the arm is used with the mounting member 22 for the columns 60 arranged side by side along the first fence 50a so that the first detection line 10a is laid substantially horizontally at a position at a predetermined height from the ground. A plurality of 21 are arranged side by side at predetermined intervals.

Next, the first detection line 10a is locked to the tip of the arm 21 and temporarily installed. At this time, the position of the end (end) on the corner Ea side of the first detection line 10a is temporarily provided at a position aligned with the fence surface 51b of the second fence 50b. That is, as shown in FIG. 5, when the monitoring area E is viewed in a plan view, the end portion on the corner Ea side is located on the extension line extending from the second fence surface 51b.

On the other hand, the end portion of the first detection line 10a that is not on the corner Ea side is temporarily installed at the same position as the straight portion (the position on the front side that does not enter the adjacent section boundary).

Next, the end portion of the first detection line 10a that is locked to the tip end portion of the arm 21 and is not on the corner Ea side connects the tension member 30. That is, one end of the first non-conductive cable 32b is connected to this end via an insulating member 31, and a turnbuckle 33a and an elastic member are connected to the other end of the first non-conductive cable 32b. The tension adjusting member 33 is connected in the order of 33b. Further, the end portion of the elastic member 33b on the side not connected to the turnbuckle 33a and the end portion of the second non-conductive cable 32c wound around the support column 60 are connected.

Further, as shown in FIG. 5, the end of the detection line 10 on the corner Ea side is provided at a position separated from the corner Ea by a predetermined distance (for example, about 2 m from the end of the detection line 10 on the corner Ea side). It is connected to the tension member 30 which is connected to the support column 60. The method of stretching by the stretching member 30 is the same as the method of connecting the ends of the first detection line 10a that are not on the corner Ea side.

Then, the tension is adjusted by the tension adjusting member 33 so that the first detection line 10a is stretched with a predetermined tension.

(Method of laying the second detection line)
First, the arm is used with the mounting member 22 for the columns 60 arranged side by side along the second fence 50b so that the second detection line 10b is laid substantially horizontally at a position at a predetermined height from the ground. A plurality of 21 are arranged side by side at predetermined intervals.

Next, the second detection line 10b is locked to the tip of the arm 21 and temporarily installed. At this time, the position of the end (end) on the corner Ea side of the second detection line 10b is laid along the first fence 50a when the monitoring area E is viewed in a plan view, as shown in FIG. It intersects with an extension line extending from the end on the corner Ea side of the first detection line 10a, and is further extended from the intersection P of both lines to a position exceeding a predetermined length.

Here, the length extending from the intersection P is extended to such an extent that it can be detected that an intruder has entered the gap between the first detection line 10a and the second detection line 10b. That is, a length that can be detected by an intruder that cannot be detected by the first detection line 10a whose one end is aligned with the fence surface 51b of the second fence 50b by the electric field generated in the extension portion of the second detection line 10b. Sato.

On the other hand, the end portion of the second detection line 10b that is not on the corner Ea side is temporarily installed at the same position as the straight portion (the position on the front side that does not enter the adjacent section boundary).

Next, the end portion of the second detection line 10b that is locked to the tip end portion of the arm 21 and is not on the corner Ea side connects the tension member 30. That is, one end of the first non-conductive cable 32b is connected to this end via an insulating member 31, and a turnbuckle 33a and an elastic member are connected to the other end of the first non-conductive cable 32b. The tension adjusting member 33 is connected in the order of 33b. Further, the end portion of the elastic member 33b on the side not connected to the turnbuckle 33a and the end portion of the second non-conductive cable 32c wound around the support column 60 are connected.

Further, as shown in FIG. 5, the end portion of the second detection line 10b on the corner Ea side is connected to the tension member 30 connected to the support column 60 provided at a position separated from the corner Ea by a predetermined distance. Let me. The method of stretching by the stretching member 30 is the same as the method of connecting the ends of the second detection line 10b that are not on the corner Ea side.

Then, the tension is adjusted by the tension adjusting member 33 so that the second detection line 10b is stretched with a predetermined tension, and the laying work of the second detection line 10b is completed.

As described above, in the method of laying the detection line 10 at the corner Ea of the monitoring area E, the first detection line 10a and the second detection line 10b are not crossed, and the laying method has two characteristic requirements. There is.

As the first feature requirement, the position of the end portion on the corner Ea side of the first detection line 10a is aligned with the fence surface 51b of the second fence 50b (that is, as shown in FIG. 5, monitoring. When the area E is viewed in a plan view, the end portion on the corner Ea side is located on the extension line extending from the second fence surface 51b).

As a second feature requirement, the position of the end portion on the corner Ea side of the second detection line 10b is along the first fence 50a when the monitoring area E is viewed in a plan view as shown in FIG. It intersects with an extension line extending from the end of the first detection line 10a laid on the corner Ea side, and extends from the intersection P of both lines to a position further exceeding a predetermined length. Further, the length extending from the intersection P is extended to such an extent that an intruder who has invaded the distance between the first detection line 10a and the second detection line 10b at the corner Ea can be detected.

As a result, the electric fields do not interfere with each other between the first detection line 10a and the second detection line 10b, so that the electric field strength does not decrease and an intruder can be reliably detected. Further, the extension portion of the second detection line 10b makes it possible to detect an intruder that cannot be detected by the first detection line 10a.

In the method of laying the corner portion Ea described above, in FIG. 5, the position of the end portion on the corner portion Ea side of the first detection line 10a is aligned with the fence surface 51b of the second fence 50b, and the second detection line This is an example in which the position of the end portion on the corner Ea side in 10b is extended to a position exceeding a predetermined length from the intersection P of both lines, but the present invention is not limited to this.
That is, the end of one detection line 10 (first detection line 10a or second detection line 10b) adjacent to the corner Ea on the corner Ea side is aligned with the fence surface, and the other detection line 10 (first detection line 10b) is aligned with the fence surface. The end on the corner Ea side of the detection line 10a or the second detection line 10b) may be extended by a predetermined length from the intersection P. Therefore, for example, the corner Ea on the second detection line 10b may be formed. The position of the end on the side is aligned with the fence surface 51a of the first fence 50a, and the position of the end on the corner Ea side of the first detection line 10a is extended by a predetermined length from the intersection P. You can also do it.

[4. Action / effect]
As described above, in the intrusion detection sensor 1 in the present embodiment, when the detection line 10 is stretched, the non-conductive cable 32 having substantially no conductivity and elasticity is used as the stretching member 30. Therefore, the intruder can be reliably detected at the section boundary between the sensors without reducing the electric field strength at the section boundary of the detection line 10 of the adjacent intrusion detection sensor 1.

Further, the detection lines 10 of the intrusion detection sensors 1 adjacent to each other other than the corner Ea of the monitoring area E are stretched at least at intervals on the section boundary side of each detection line 10 so that no one can pass through. As a result, there is almost no interference between the electric fields generated by the adjacent detection lines 10 at the section boundary of the adjacent intrusion detection sensors 1, so that the detection sensitivity does not decrease. Therefore, an intruder can be reliably detected. Further, since the distance between the ends of the detection lines 10 at the section boundary is a width that cannot be passed by a person, an intruder does not enter through the gap between the adjacent detection lines 10.

In the corner portion Ea of the monitoring area E, the position of the end portion of the first detection line 10a on the corner portion Ea side is aligned with the fence surface 51b of the second fence 50b (that is, as shown in FIG. 5). When the monitoring area E is viewed in a plan view, the end portion on the corner Ea side is located on the extension line extending from the second fence surface 51b). Further, as shown in FIG. 5, the position of the end portion on the corner Ea side of the second detection line 10b is the first position laid along the first fence 50a when the monitoring area E is viewed in a plan view. It intersects with an extension line extending from the end of the detection line 10a on the corner Ea side, and extends from this intersection P to a position further exceeding a predetermined length. Further, the length extending from the intersection P is extended to such an extent that an intruder who has invaded the distance between the first detection line 10a and the second detection line 10b at the corner Ea can be detected.

As a result, the electric fields do not interfere with each other between the first detection line 10a and the second detection line 10b, so that the electric field strength does not decrease and an intruder can be reliably detected. Further, the extension portion of the second detection line 10b makes it possible to detect an intruder that cannot be detected by the first detection line 10a.

1 ... Intrusion detection sensor 10 ... Detection line (10a ... First detection line, 10b ... Second detection line)
11 ... Oscillation line 12 ... Sensing line 20 ... Support member 21 ... Arm tree 22 ... Mounting member 30 ... Stretching member 31 ... Insulation member 32 ... Non-conductive cable (32a ... Thimble, 32b ... First non-conductive cable, 32c … Second non-conductive cable)
33 ... Tension adjusting member (33a ... Turnbuckle, 33b ... Elastic member)
40 ... Controller 50 ... Fence 60 ... Support (fence pole of fence)
E ... Monitoring area Ea ... Corner of the monitoring area

Claims (3)

In an intrusion detection sensor in which a corner portion of the monitoring area is formed by a first fence and a second fence surrounding the outer periphery of the monitoring area and an intruder near the monitoring area is detected.
A detection line that generates an electric field with an applied AC signal and outputs a detection signal according to the change in the electric field.
A support member that supports the detection line in a substantially horizontal direction along the fence at a position separated from the fence surface by a predetermined distance outside the monitoring area.
An insulating member is connected to one end of a non-conductive cable having substantially no conductivity and elasticity, a tension adjusting member is connected to the other end of the cable, and the detection line is connected via the insulating member. And the tensioning member to be stretched with a predetermined tension applied to the
With
The first detection line stretched along the first fence is stretched at a position where the corner side end is aligned with the fence surface of the second fence.
The second detection line stretched along the second fence is located on the corner side of the first detection line when the corner side end is viewed in a plan view of the monitoring area. An intrusion detection sensor characterized in that it intersects an extension line extending from an end position and is stretched at a position exceeding a predetermined length from the intersection of both lines. The claim is characterized in that the second detection line extends from the intersection to a length that can be detected by an intruder who has entered through the gap between the first detection line and the second detection line. Item 1. The intrusion detection sensor according to item 1. It is provided in units of sections divided into a plurality of sections along the first fence and the second fence.
The detection lines of the intrusion detection sensors adjacent to each other other than the corners of the monitoring area shall be stretched with the distance between the ends on the section boundary side of each detection line set to at least a width that does not allow people to pass through. The intrusion detection sensor according to claim 1 or 2.

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