JPH0512577A - Invader detecting device - Google Patents

Abstract

PURPOSE:To remove misdetection due to the natural extension of a cable-like body caused by a temperature difference or the like. CONSTITUTION:An invader detecting device provided with a cable-like body streached to an alarm section, an energizing means for tensely energizing the cable-like body and a movement detecting means for detecting the movement of a specific point on the cable-like body in the tensing direction of the cable- like body or its reverse direction is also provided with integrating means 14, 15 for integrating the moving variable of the specific point and outputting detection signals when the moving variable reaches a set point, and timer means 16, 17 for counting time elapsed for initializing the means 14, 15 and the means 16, 17 are constituted so that their counting time are initialized in each detection of the movement of the specific point and the means 14, 15 themselves are initialized when the counting time reaches the set time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cord stretched in a warning area, a biasing means for pulling and pushing the cord, and the cord extending in the pulling direction of the cord or the opposite direction. The present invention relates to an intruder detection device including a movement detection unit that detects movement of a specific point of a strip.

[0002]

2. Description of the Related Art A cord of such an intruder detecting device is stretched along a fence provided around a guard area, for example. In general, one end thereof is fixed to a column, and the other end is pulled and biased by a biasing means with a predetermined tension. When an intruder who goes over the fence touches the cord and a tension higher than the biasing force of the biasing means is applied to the cord, the specific point of the cord moves in the direction opposite to the biasing force. Also, if the cord is cut,
A specific point on the cord moves in the direction of the urging force (tensile direction)

Therefore, a detecting means for detecting the movement amount of a specific point of the cord-like body is provided, and a detection signal is output when the movement amount more than a set amount occurs. Here, the specific point of the cord means a point on the cord assumed to detect the movement of the cord quantitatively, and generally, the specific point in the portion as close as possible to the biasing means. The amount of movement (for example, the tip of the cord) is detected.

[0004]

One of the problems to be solved in the above-mentioned intruder detection device is erroneous detection due to natural expansion and contraction of the cord. That is, for example, due to the temperature difference between day and night, the cord expands or contracts, and as a result, a specific point of the cord moves. In this case, it is necessary to ignore the occurrence of the movement amount equal to or more than the set amount and not output the detection signal.

The present invention has been made in view of the above circumstances, and an object thereof is to eliminate erroneous detection due to natural expansion and contraction of cords.

[0006]

An intruder detection device according to the present invention comprises a cord-like body stretched over a warning area, a biasing means for pulling and biasing the cord-like body, and a pulling direction of the cord-like body or And a movement detecting means for detecting the movement of the specific point of the cord in the opposite direction, the characteristic configuration is that if the movement amount of the specific point is integrated and the movement amount reaches a set amount. An integrating means for outputting a detection signal and a measuring means for measuring an elapsed time for initializing the integrating means are provided, and the measuring means has its own measuring time each time the movement of the specific point is detected. It is configured such that it is initialized and the integrating means is initialized as the time count reaches a set time.

[0007]

According to the above characteristic structure, the accumulating means integrates the movement amount of the specific point of the cord based on the detection information of the movement detecting means, and outputs the detection signal when the movement amount reaches the set amount.
For example, when a rotary encoder or the like is used as the movement detection means, a pulse signal having a pulse number proportional to the movement amount is obtained. Therefore, if the integration means (counter) integrates the number of pulses and the integrated value reaches the set value, The detection signal is output.

On the other hand, the time counting means, which is initialized each time the movement of the specific point is detected, initializes the integrating means as the set time is reached. Here, "every time movement of a specific point is detected" means "every time there is movement of the minimum unit that can be detected by the movement detecting means". For example, in the case of the rotary encoder, The movement amount corresponding to the pulse corresponds to the minimum unit movement amount that can be detected.

Therefore, if the movement of the specific point is not detected within the set time (that is, if there is no movement of the minimum unit or more that can be detected), the integrating means is initialized. That is, the amount of movement accumulated so far is cleared. On the other hand, if the movement of the specific point is detected within the set time (that is, if there is a movement of the minimum unit or more that can be detected), the clocking means is initialized,
At that point, the set time starts to be counted anew. When this operation continues and the accumulated movement amount reaches the set amount, the detection signal is output.

[0010]

According to the present invention, as described above, the detection signal is not transmitted until the movement of the specific point whose movement amount within the set time is the minimum unit or more continues and the accumulated movement amount reaches the set amount. Is output. In other words, only the movement at the predetermined speed or higher is integrated as the effective movement amount. Therefore, the detection signal is not output in the case of gentle movement such as expansion and contraction of the cord due to the temperature difference between day and night. Therefore, the influence of such expansion and contraction is excluded to provide an intruder detection device in which erroneous detection is unlikely to occur.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a cord 2 (hereinafter referred to as a wire) 2 is stretched along a fence 1 provided around the guard area, and one end 2 a thereof is fixed to the fence 1.
The other end of the wire 2 is connected to the tension detector 3 installed on the fence 1. Further, the wire 2 is passed through a sleeve 4 provided at a predetermined interval in the fence 1 so that a change in the tension of the wire 2 is transmitted to the tension detector 3 no matter where the force is applied to the wire 2. ing.

As shown in FIG. 2, the tension detector 3 includes an urging means 5 for pulling and urging the wire 2, and a movement detecting means 6 for detecting movement of the tip of the wire 2 as a specific point. .. The urging means 5 is composed of a tubular body 7 in which a mainspring is installed. When the rotary shaft 7a is rotated by using a jig and the mainspring is wound up, the auxiliary wire 8 wound around the outer circumference of the tubular body 7 is pulled by a predetermined biasing force.

The auxiliary wire 8 is the pulley 6 of the detecting means 6.
After being wound around b and the pulley 9b of the movable pulley 9, the end is fixed to the case 3a. The tip of the wire 2 is fixed to the support frame 9a of the movable pulley 9. Therefore, the biasing means 5
Means that the wire 2 is pulled and urged via the auxiliary wire 8 and the movable pulley 9.

The movement detecting means 6 comprises a two-phase rotary encoder 6a and a pulley 6b fixed to its rotary shaft. The auxiliary wire 8 is wound around the pulley 6b, and when the pulley 6b is rotated by the movement of the auxiliary wire 8, the rotary encoder 6a outputs a pulse signal having a pulse number proportional to the moving amount of the auxiliary wire 8. Therefore, the movement detecting means 6 detects the movement of the tip of the wire 2 via the movable pulley 9 and the auxiliary wire 8.

With the above structure, when a person trying to enter beyond the fence 1 comes into contact with the wire 2 and changes its tension, the auxiliary wire 8 of the tension detector 3 moves, and the pulse signal is outputted from the rotary encoder 6a. Is output. When installing this device, the length of the wire 2 is adjusted so that the movable pulley 9 is located in the approximately middle part of the movement allowable range, and the tension of the wire 2 is a predetermined tension (for example, 10 Kg).
As described above, the power spring of the biasing means 5 is wound up so that

Therefore, the change in tension of the wire 2 is
Is detected not only when it is pulled, but also when it is loosened or cut. That is, the tip of the wire 2 moves in either the pulling direction or the slacking direction, and the amount of movement and the moving direction can be detected by processing the two types of pulse signals output from the rotary encoder 6a. it can.

In addition, the rotary encoder 6
Two pulse signals (A-phase signal and B-phase signal) shifted by ¼ cycle are output from a, and the moving direction is identified depending on which pulse signal has the advanced phase. Actually, each pulse signal is input to the detection circuit unit 10,
First, the waveform is shaped and then input to the detection circuit shown in the block diagram of FIG. The operation of this circuit will be described below with reference to the time chart of FIG.

The waveform-shaped set of the A-phase signal and the B-phase signal is input to the first input circuit 11 and the second input circuit 12. Then, by the function of the interlock circuit 13,
The first input circuit 11 outputs a first pulse signal that changes only when the rotary encoder 6a is normally rotated, that is, when the wire 2 is pulled, and the second input circuit 12 outputs the first pulse signal when the rotary encoder 6a is reversely rotated. That is, the second pulse signal that changes only when the wire 2 is loosened is output.

The first pulse signal and the second pulse signal are input to the first counter 14 and the second counter 15 as counting signals, respectively. The first counter 14 integrates the number of pulses of the first pulse signal, and outputs a first detection signal when the integrated value reaches a set value (for example, 3). Similarly, the second counter 15 integrates the number of pulses of the second pulse signal, and outputs the second detection signal when the integrated value reaches the set value.

Therefore, the first counter 14 corresponds to an integrating means which integrates the movement amount of the tip of the wire 2 in the pulling direction and outputs a detection signal when the movement amount reaches a set amount (for example, 2 mm). Similarly, the second counter 15 corresponds to an integrating unit that integrates the movement amount in the loosening direction and outputs a detection signal when the movement amount reaches the set amount.

Both counters 14 and 15 are initialized (reset) when the H pulse interval of each pulse signal, which is the respective counting signal, exceeds a set time (about 6 seconds). This is to prevent the detection signal from being output in the case of gentle movement such as movement of the tip of the wire 2 due to natural contraction of the wire 2 due to temperature difference or the like.

Specifically, as shown in FIG. 1, a first timer 16 and a second timer 17 are provided as timing means for timing the elapsed time for initializing both counters 14 and 15, and their respective outputs are provided. Is connected to the reset input of the first counter 14 or the second counter 15. Both timers 16,
Reference numeral 17 is a CR timer using the charging time constant of the capacitor, and the output changes from the L level to the H level when a set time (about 6 seconds) elapses.

The charges of the capacitors of both timers 16 and 17 are configured to be discharged when the first pulse signal and the second pulse signal become H level, respectively. That is,
Each timer 1 each time each pulse signal goes high
The time counts 6 and 17 are initialized, and the time count of the set time (about 6 seconds) is started as the time returns to the L level. The pulse signals change as described above when the movement of the tip of the wire 2 is detected as a pulse signal from the rotary encoder 6a.

If a description is added based on FIG. 2, if the H pulse interval in the first pulse signal is less than the set time (about 6 seconds) as shown in (a), the first counter reset signal is set to H during this period. You will never reach the level. Therefore, the first counter 14 is not initialized, and the first counter 14 is not initialized.
The first detection signal is H at the third pulse of the pulse signal.
Become a level.

On the other hand, as shown in (b), when the H pulse interval in the first pulse signal is equal to or longer than the set time, the first counter reset signal reaches the H level as the set time is reached. Therefore, since the first counter 14 is initialized, the first detection signal remains L level even when the third H pulse of the first pulse signal comes.

Further, as shown in FIG. 1, the first counter 14
The second pulse signal is also connected to the reset terminal of via the diode 18. Therefore, the first counter 14 is also initialized by the H level of the second pulse signal.
Similarly, the first pulse signal is connected to the reset terminal of the second counter 15 via the diode 19, and the second counter 15 is also initialized by the H level of the first pulse signal.

That is, as can be seen from the time chart of FIG. 2, the tip of the wire 2 is moved only in one of the pulling direction and the loosening direction, and the moving amount reaches the set amount (3 pulses). It is configured to output a detection signal when it does. With such a configuration, the detection signal is not erroneously output when the tip of the wire 2 reciprocates in small steps due to the influence of wind or the like.

Other examples will be listed below. In the above-described embodiment, the setting value of the second counter 15 may be larger than the setting value of the first counter 14 (for example, 5). This is because if the movement of the wire specific point in the loosening direction occurs independently, it is difficult to think except when the wire is cut, except for the expansion of the wire, and when the wire is cut, a sufficiently large movement occurs. ..

Since the first timer 16 and the second timer 17 as the time measuring means do not require much accuracy, they are configured by CR timers that use the charging time constant of the capacitor, but they are accurate by the basic clock oscillation circuit and the timer IC. A timer may be configured. Further, the H level of the first detection signal or the second detection signal may be latched and output for a predetermined time. In addition, various changes can be made to the specific configuration of the detection circuit.

In the above embodiment, the wire tip is pulled and urged and the movement amount of the wire tip is detected, but the specific point for detecting the movement amount does not necessarily have to be the wire tip portion. For example, the detection means may be provided at a position apart from the urging means for pulling and urging the tip of the wire to detect the movement of a specific point defined in the middle portion of the wire.

The urging means is not limited to the one using the mainspring spring as in the above embodiment, but can be changed such as using one or two or more coil springs. Further, the movement detecting means is not limited to the rotary encoder. For example, a differential transformer may be used to integrate digital values obtained by A / D converting the voltage generated according to the amount of movement.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a block diagram showing a detection circuit of an intruder detection device according to an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the detection circuit of the intruder detection device.

FIG. 3 is an internal structure diagram of a tension detector of the intruder detection device.

FIG. 4 is a schematic view showing an installation state of the intruder detection device.

[Explanation of symbols]

 2 cord 5 urging means 6 movement detecting means 14, 15 integrating means 16, 17 time measuring means

Claims (1)

Claim: What is claimed is: 1. A cord (2) stretched in a caution area, a biasing means (5) for pulling and biasing the cord (2), and the cord (2). ) A movement detecting means (6) for detecting the movement of the specific point of the cord (2) in the pulling direction or the opposite direction thereof, and the movement amount of the specific point is integrated. If the moving amount reaches the set amount, the integrating means (14), (15) for outputting a detection signal, and the counting means (16) for measuring the elapsed time for initializing the integrating means (14), (15). ), (17), and the time measuring means (16), (17) initializes its own time measurement each time the movement of the specific point is detected, and the time measurement time reaches the set time. An intruder detection device configured to initialize the accumulating means (14), (15) according to the above.