JP3093834B2 - Intrusion object determination method for security sensor using dual twin type detection element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for judging an intruding object of a security sensor using a dual twin type detecting element, and more particularly to a method for judging an intruding object detected by fuzzy processing a signal taken out from the detecting element. It is about.

[0002]

2. Description of the Related Art In a so-called dual twin system in which two sets of twin-type pyroelectric elements are arranged as upper and lower detection elements, for example, a detection signal a of an upper element twin and a detection signal b of a lower pyroelectric element twin are detected by a CPU as follows. As a result, when X is equal to or higher than a certain level (threshold level L), an alarm output is generated. X = | a + b |-| ab |

FIG. 1 schematically shows the relationship between the arrangement of elements for generating such signals a and b and an intruding object or the like detected by these (hereinafter referred to as a “detected object”).
Figure 1 (A) in the detected object is a human body, an upper element Twin a ⁺ and a ^- detects the human body top, bottom element twin b ⁺ and b ^- indicates a state of detecting a human body bottom. FIG. 1B shows a state in which the detection object is a small animal such as a mouse, and only the lower element twins b ⁺ and b ⁻ detect far infrared rays emitted from the small animal. FIGS. 2A and 2B show the relationship between the signals of the elements a and b corresponding to FIGS. 1A and 1B, the processed signal X and the level L, and the corresponding alarm. FIG. Therefore, as long as the X arithmetic expression is followed, according to the dual twin system, the difference between an intruder (human) and a small animal can be identified, and an alarm can be issued only in the former case.

[0004]

However, in the above-described ordinary dual twin system, it is possible to determine to some extent whether or not the sensing object is a human, but the radiation heat generated by the sensing object of each size can be determined. Comprehensively judge the degree of (temperature difference from the normal background), determine that it is human, or obtain a conclusion that it is human, and generate an alarm, so-called fuzzy processing response could not be done .

An object of the present invention is to provide a
A signal processing method of obtaining the temperature difference between the normal background and the size of the background caused by the object that has entered the monitoring area and the size information from the signals of b and b, and fuzzy processing the two information to determine the alarm output. It is to be.

[0006]

In order to achieve the above object, in the method for determining a detected object according to the present invention, a twin arrangement of pyroelectric elements for detecting a movement of a heat source in a horizontal direction in a staggered manner is provided. Using a dual twin type security sensor provided in a row, the output of the upper pyroelectric element twin is an analog value a, the output of the lower pyroelectric element twin is an analog value b,
As a premise (1), | a | or | b | in the case of | a | = | b | 以上 0 is equal to or higher than the detection lower limit level LL, information α of the temperature difference from the normal time by the heat source, and the heat source When the information β regarding the size of α is | α ||||| (however, the temperature difference ∝α) β = | a | − | b | (however, the size ∝ | 1 / β |), It is characterized by issuing an alarm when it is determined that there is a high possibility that the heat source body is an intruding person by various combinations of a temperature difference equal to or more than a predetermined value and a size equal to or more than a predetermined value. is there.

In a more particular aspect of the invention,
The temperature difference is classified into low, slightly low, slightly high, and high according to the temperature difference information α, and the size is classified into small, slightly small, slightly large, and large according to the size-related information β. ) A human being if the temperature difference is substantially high and the size is also substantially large; (2) a small animal if the temperature difference is substantially high and the size is small ; But
If the temperature difference is large, the temperature difference is slightly low, and the size is substantially large, the possibility of being a human is high. (4) The temperature difference is slightly low, the size is substantially small, and the temperature difference
The heat source is determined based on the rule that if the size is substantially high and the size is slightly small, it is likely that the animal is a small animal. (5) If the temperature difference is low and the size is not large, it is a disturbance. It is assumed that. In this case,
"High" includes "slightly high" and "high," and "substantially high."
"Low" includes "slightly low" and "low", and is substantially "high"
"Somewhat large" and "large" include, "substantially small"
It is a concept that includes “slightly small” and “small”.

[0008]

In the above-described configuration, an embodiment in which the signals a and b generally consisting of the upper and lower twin elements substantially exist is as shown in FIG.
FIG. 4 shows a state in which only one exists. In each figure, (A) shows the case where the signal strength has a substantial magnitude, and (B) shows the case where the signal strength is weak.
In these figures, the state of FIG. 3A in which the size of the detection object is large and the temperature is high should clearly issue an alarm as the presence of an intruder (human), but the size is large but the temperature difference is low. In the state of FIG. 3B, how to make a determination is a problem. Further, in the case of FIG. 4 corresponding to the case where the size of the detection object is small, it is clear that the alarm should not be issued in both the state of the large temperature difference (A) and the state of the low temperature (B). It is.

As apparent from these figures, since the absolute values of the signals a and b are partial temperature difference information, the temperature difference α of the whole detected object is represented by the sum of them, and the size information 1 / β
Is expressed as being larger as the absolute value of the difference between the absolute values is smaller in the following premise. That is, α = | a | + | b | β = | a | − | b | In this case, | a | or | b | other than | a | = | b | = 0
Has an analog value equal to or higher than the above-described detection lower limit level LL, and the case where α = 0 when | a | = | b | ≦ LL is ignored.

Accordingly, if the temperature difference information α and the size information β obtained in this way can be almost determined that the detected object is a human, or it can be considered that there is a possibility that the detected object is a human, the alarm is surely issued. Can be emitted.

More specifically, if the temperature difference information α is “low”,
Classified into 4 levels of "Slightly low", "Slightly high" and "High"
By classifying the size-related information 1 / β into four levels of “small”, “slightly small”, “slightly large” and “large”, 4 × 4
= 16 types of classification elements, (1) human
(2) It is a small animal, (3) It is likely that it is a human, (4) It is likely that it is a small animal, (5) It is a disturbance, etc. If it is desired to prevent the intrusion, the intrusion can be specified and a warning can be made.

[0012]

FIG. 5 shows the size-related information 1 / β as described above.
Are classified into four stages of "small", "slightly small", "slightly large" and "large", and temperature difference information processing is classified into four stages of "low", "slightly low", "slightly high" and "high" 6 is a chart showing the judgment categories when classified into. That is, if the temperature difference is “low” and the size is “slightly large” or less, this area is determined to be a disturbance. In addition, if the temperature difference is “slightly low” and the size is “small” or “slightly small”, and if the size is “slightly small” and the temperature difference is “slightly high” or “high”, small animals are possible. If the size is “small” when the temperature difference is “slightly high” and “high”, it is determined that a small animal has entered.

In the remaining area in FIG. 5, if the temperature difference is “low” and the size is “large”, and if the temperature is “slightly low” and the size is “slightly large” or more, this area is It is determined that the person is a human if the temperature difference is “slightly high” or more and the size is “slightly large” or more.

FIGS. 6 and 7 show an example of a membership function serving as a criterion for classification as described above, with respect to the magnitude of the temperature difference and the magnitude of the size, respectively. In the classification judgment, the fitness of each element is obtained from these membership functions. For example, if the input is α1 in FIG.
In the case of β1 in FIG. 7, the suitability of the temperature difference “slightly high” is “1”, and the suitability of the size “small” is “1”. It is also clear that the fitness of the other elements is zero. Therefore, this state coincides with the classification shown in FIG. 5 that the animal is a small animal when the temperature difference is slightly high and the size is small.

In the actual calculation processing, the degree of conformity of each element is obtained, the calculation is performed for each of the above-described five categories, and the result is defuzzified to determine whether or not to output an alarm finally. Is to judge.

[0016]

The present invention is constructed as described above, and performs fuzzy processing according to the installation environment of a security sensor using a dual twin type detection element to compensate for a safe and secure sensor function. is there.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a relationship between an arrangement of a dual twin type detection element and a detection object.

FIG. 2 is a sequence waveform diagram showing a signal processing sequence in conventional dual twin signal processing corresponding to each case of FIG.

FIG. 3 is a detection waveform diagram when the dual twin type element detects a detection object having a large size.

FIG. 4 is a detection waveform diagram when the dual twin type element detects a small-sized detection object.

FIG. 5 is a chart for classifying a detection object into four categories based on a size and a temperature difference of a detection object, and determining what the detection information indicates by a combination thereof.

FIG. 6 is an example of a membership function relating to the level of a detected temperature difference.

FIG. 7 is an example of a membership function regarding the size of a detection object.

[Explanation of symbols]

 a Detection signal of upper element twin b Detection signal of lower element twin X Conventional processing signal L Conventional processing signal threshold level LL Detection lower limit level

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-213396 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08B 13/18-13/193 G01V 8 / 20

Claims (2)

(57) [Claims] An output of an upper pyroelectric element twin is provided by using a dual twin type security sensor in which a twin arrangement of pyroelectric elements for vertically and horizontally detecting a movement of a heat source body in a staggered manner is provided. Is the analog value a, and the output of the lower pyroelectric element twin is the analog value b. As a precondition, | a | = | b
| A | or | b | when | ≠ 0 is the lower detection limit level LL
It is assumed that the information α on the temperature difference from the normal time by the heat source and the information β on the size of the heat source are α = | a | + | b | (provided that the temperature difference ∝α) β = | a | − | B | (however, size ∝ | 1 / β |), the heat source body may be intruded by the temperature difference of a predetermined value or more and various combinations of the sizes of the predetermined value or more. A method for determining an intruding object of a security sensor using a dual twin type detection element, wherein an alarm is issued when it is determined that there is a high possibility. 2. The temperature difference is classified into low, slightly low, slightly high, and high according to the information α of the temperature difference, and the size is small, slightly small, slightly large, and large according to the size-related information β. (1) a human being if the temperature difference is substantially high and the size is substantially large; (2) a small animal if the temperature difference is substantially high and the size is small; (3) temperature If the difference is low and the size is large, and the temperature difference is slightly lower,
If the size is substantially large, it is more likely that the person is a human. (4) The temperature difference is slightly lower and the size is substantially smaller.
If the temperature difference is substantially high and the size is slightly small, it is highly likely that the animal is a small animal. (5) If the temperature difference is low and the size is not large, it is a disturbance. The method of claim 1, wherein the determining is performed.