JP2008171195A - Crime-preventive sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crime-preventive sensor which can correctly detect a human body with a low cost configuration. <P>SOLUTION: Distance information from an image sensor 11 to a material object 19 is found based on an imaging signal acquired by a distance sensor 12 in a distance computing section 15b. An occupancy ratio which is a ratio occupied by an area of the material object 19 imaged by the image sensor 11 within a whole imaging field of view of the image sensor 11 is found in an occupancy percentage computing section 15a. In an actual size computing section 15c, a whole area of the view field of the image sensor 11 is found by use of viewing angle of the image sensor 11 and distance information, an actual area of the material object 19 is found by multiplying this area by the occupancy percentage, moreover, shape information of the material object 19 is found from information relating to an occupied pixel by an image sensor 11, and actual size information on the material object 19 is found from this shape information and actual area. In a determination section 16, whether the imaged material object 19 is a specific material object 19 or not is determined by comparing real area and/or real size information with comparison information which shows size of a specific material object 19. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a security sensor that is installed in a security area such as a building where security measures are required and detects a person entering the sensor detection area.

  Conventional security sensors use pyroelectric infrared sensors that detect the human body by sensing the amount of infrared radiation that has entered the detection area with this sensor, and humans and objects enter the image sensor. It is common to store an image that is not in operation, extract the object from the stored background when the object enters the field of view of the image sensor, and detect whether it is a human body from the movement is there.

Examples of this type of conventional security sensor include those described in Patent Documents 1 and 2.
In the technique of Patent Document 1, a moving object is detected based on an image of visible light by a moving object detection sensor, and an infrared ray amount or an infrared change amount is detected by an infrared sensor. Then, the size of the moving object detected by the moving object detection sensor is analyzed, the size of the moving object is equal to or larger than a predetermined size, and the amount of infrared rays or the amount of change of infrared rays detected by the infrared sensor is a predetermined value. When it becomes above, it determines with this moving body being a human body.

In the technique of Patent Document 2, an infrared light reception signal is analyzed by an optical waveform analysis unit, and thereby a first evaluation value E1 is calculated. Image information is analyzed by the image analysis unit, thereby calculating a second evaluation value E2. While comprehensively evaluating each evaluation value E1, E2, the comprehensive determination unit adds the two evaluation values E1, E2 depending on the situation, and performs a comprehensive determination based on the added value. The comprehensive judgment unit judges the presence of a human body and the existence of a plan. The position of the human body in the image (distance from the sensor) is specified based on the image information, and the sensitivity of the infrared sensor is adjusted based on the position. Further, the moving speed of the human body is obtained using the image information, and sensitivity adjustment is performed based on the moving speed.
JP 2000-155177 A JP 2000-341675 A

  However, the conventional security sensor has the following problems. In the security sensor provided with the pyroelectric infrared sensor described in Patent Document 1, by setting a threshold value of the infrared radiation amount, a human body having a large infrared radiation amount and a small animal such as a dog or a cat having a small infrared radiation amount Can be distinguished. However, even for the same human body, the amount of charge due to infrared rays varies depending on the distance from the infrared sensor to the human body, so if you set a low threshold to detect a human body at a long distance, small animals such as dogs and cats at a close distance Detects even if it enters the sensing area. In addition, regarding an object having a large amount of heat radiation compared to a person such as an automobile, the heat is detected even when passing through a place farther than the distance at which the human body can be sensed. In this way, there arises a problem that the security sensor detects other than the intrusion or approach of the person who is the original purpose.

  In addition, in the security sensor equipped with an image sensor, an image in the field of view of the image sensor is stored in advance in the absence of an intruder, and an object enters the field of view and the image is changed. Is to be detected. In this case, it is possible to determine whether the person is a person from the shape and movement of the object, but depending on the angle of the object with respect to the image sensor, the shape to be imaged differs. difficult. It is also possible to determine whether the object is a human body from the moving speed of the object, but since the actual moving distance varies depending on the distance from the image sensor, the absolute value of the speed cannot be calculated. It is also difficult to judge. In addition, it is possible to recognize the size of the object to some extent by the ratio of the imaged object to the field of view (all pixels), but this is only possible when the distance of the object from the image sensor is known. It is done.

  In Patent Document 2, an image sensor lens is not a fixed focus but an image sensor having a function of finely focusing, and a rough distance is obtained by an image sensor by searching for a point where an object is focused by a contrast method. It is also possible to obtain However, since the lens and the housing are much more expensive than the fixed focus object, the security sensor becomes expensive.

  The case where the image sensor is used will be further described. As shown in FIG. 6, when the small object 1 and the object 3 considerably larger than the small object 1 exist at a distance from each other, in other words, the size of the object 1 and the object 3 is large. Even if they are different, the ratio of the object 1 in the field of view 2 near the image sensor f1 of the image sensor is exactly the same as the ratio of the object 3 in the field of view 4 far away from the image sensor f1. This is because the field of view of the image sensor f1 varies greatly depending on the distance from the image sensor. Therefore, for example, a small insect near the image sensor f1 and a person at a distance from the image sensor f1 are recognized with the same size. Therefore, the human body and other than that only by the size reflected on the image sensor f1. You cannot distinguish things. Therefore, even in the crime prevention sensor using the image sensor, there is a frequent problem that the crime prevention sensor detects other than the conventional intrusion or approach of a person.

As described above, the security sensor detects intrusion and approach other than the human body, and accordingly, malfunctions in which alarm devices such as lights and alarms associated with the security sensor are operated frequently occur. For this reason, there are cases where the power of the security sensor installed in a building or the like is intentionally turned off. In this case, the role of the original security sensor is often not fulfilled at all.
This invention is made | formed in view of such a subject, and it aims at providing the crime prevention sensor which can detect a human body appropriately with an inexpensive structure.

  In order to achieve the above object, a security sensor according to claim 1 of the present invention uses an image sensor that captures an image of a subject in a field of view with an image sensor through a lens, and the subject imaged by the image sensor is a specific subject. In the security sensor for determining whether or not, a distance sensor that obtains a plurality of imaging signals by imaging the distance to the subject with an imaging device via at least a pair of lenses, and a plurality of imaging obtained by the distance sensor A distance from the distance sensor to the subject is obtained using a signal phase difference, and this distance is a distance from the image sensor to the subject using information on a positional relationship between the image sensor and the distance sensor. Distance calculation means for converting into distance information, and the area of the subject imaged by the image sensor is in the entire imaging field of the image sensor. An occupancy ratio calculating means for obtaining an occupancy ratio, a viewing angle of the image sensor, and the distance information to obtain an actual area of the entire field of view of the image sensor, and multiplying the actual area by the occupancy ratio Then, the actual area of the subject at the distance of the distance information is obtained, and the actual size calculation means for obtaining the shape information of the subject from the number of pixels picked up by the image sensor, and the actual area of the subject is determined as the size of the specific subject. And determining means for determining whether or not the imaged subject is a specific subject by comparing it with comparison information indicating a value within a predetermined range.

  According to this configuration, the actual area of the subject imaged by the image sensor is obtained, and this actual area is compared with the comparison information that is a threshold value to determine whether the imaged subject is a specific subject. did. As a result, when the security sensor is installed in a security area such as a building where security measures are required, it can be accurately identified when a person (subject) enters the sensor sensing area. With conventional security sensors, the size of the subject cannot be properly identified according to the distance from the sensor, so even if a small animal such as a dog or cat at a close distance or a car larger than a person enters the sensing area The subject could not be accurately identified depending on the angle of the subject relative to the image sensor.

The security sensor according to claim 2 of the present invention is the security sensor according to claim 1, wherein the actual size calculation means further obtains shape information of the subject from pixel arrangement information of a region where the subject is imaged in the image sensor. A function for obtaining the actual size information of the subject from the shape information and the actual area, and the determining means determines at least one of the actual area information of the subject and the actual size information of the subject as a specific subject size. It is characterized by determining whether or not the imaged subject is a specific subject by comparing with comparison information indicated by a value in a predetermined range.
According to this configuration, more accurate determination can be performed by adding information on actual dimensions.

The security sensor according to claim 3 of the present invention is the security sensor according to claim 1 or 2, wherein the image sensor and the distance sensor are arranged so that the optical axes of the lenses are parallel and close to each other. Features.
According to this configuration, when the distance calculation unit converts the distance from the distance sensor to the subject using the information on the positional relationship between the image sensor and the distance sensor, the distance calculation unit converts the distance information from the image sensor to the subject. This calculation can be simplified.
According to claim 4 of the present invention, the security sensor according to claim 1 changes the number of distance measuring points of the distance sensor according to any one of claims 1 to 3 in accordance with imaging information obtained by the image sensor. It is characterized by.
According to this configuration, if the number of distance measuring points of the distance sensor is reduced, the distance calculation time in the distance calculation means can be shortened.

  The crime prevention sensor according to claim 5 of the present invention uses a pyroelectric infrared sensor that senses the amount of infrared radiation of a subject in the field of view with an electric charge, and whether the subject sensed by the pyroelectric infrared sensor is a specific subject. In the security sensor for determining whether or not, a distance sensor that obtains a plurality of imaging signals by imaging a distance to the subject with an imaging device via at least a pair of lenses, and a plurality of imaging signals obtained by the distance sensor The distance from the distance sensor to the subject is obtained using the phase difference of the distance, and the distance is calculated from the pyroelectric infrared sensor to the subject using information on the positional relationship between the pyroelectric infrared sensor and the distance sensor. Distance calculating means for converting the distance information to the distance information, and an upper threshold and a lower threshold are set according to the distance information obtained by the distance calculating means, and the pyroelectric infrared sensor And a determination unit that determines that the infrared radiation amount detected in is not a specific subject when the amount of infrared radiation exceeds the upper threshold or falls below the lower threshold, and determines that the subject is a specific subject in other cases. It is characterized by that.

  According to this configuration, when the pyroelectric infrared sensor or the distance sensor detects the intrusion of the object that is the subject, the infrared radiation amount in the field of view is detected by the pyroelectric infrared sensor, and the position and the position of the object are detected by the distance sensor. Detect distance. Then, it is possible to determine whether the intruding object is a human body or a small animal from the amount of infrared radiation obtained by the pyroelectric infrared sensor and the distance to the object obtained from the distance sensor. In addition, in order to increase the sensitivity of the pyroelectric infrared sensor, even if the directivity is increased or the sensitive angular range is narrowed by an optical system or the like, the distance sensor can know the direction of the intruder that is the subject. The pyroelectric infrared sensor can be directed in that direction. Furthermore, this can eliminate the direction dependency of the sensitivity of the pyroelectric infrared sensor.

The crime prevention sensor according to claim 6 of the present invention is the crime prevention sensor according to claim 5, wherein the pyroelectric infrared sensor and the distance sensor are arranged so that the optical axes of the lenses are parallel and close to each other. It is characterized by.
According to this configuration, the distance calculation means converts the distance from the distance sensor to the subject into the distance information from the pyroelectric infrared sensor to the subject using information on the positional relationship between the pyroelectric infrared sensor and the distance sensor. This calculation can be simplified when converting.
A crime prevention sensor according to claim 7 of the present invention is the security sensor according to claim 5 or 6, according to image information obtained by infrared detection of a subject by the pyroelectric infrared sensor. It is characterized by changing the number.
According to this configuration, if the number of distance measuring points of the distance sensor is reduced, the distance calculation time in the distance calculation means can be shortened.

The security sensor according to claim 8 of the present invention is the security sensor according to any one of claims 5 to 7, further comprising direction adjusting means for changing a direction of the pyroelectric infrared sensor, wherein the distance calculation unit is the presence of the subject. The direction adjusting means is controlled such that a calculation for determining the direction to be performed is performed, and the center of the visual field of the pyroelectric infrared sensor is directed to the calculated direction.
According to this configuration, the directivity of the pyroelectric infrared sensor can be increased to increase sensitivity, or uniform sensitivity can be obtained anywhere in the detection range of the security sensor.

The security sensor according to claim 9 of the present invention is the security sensor according to any one of claims 1 to 8, wherein the distance sensor includes a plurality of pairs of one-dimensional photosensor arrays in which the subject is imaged through two lenses. It is a multi-line optical sensor that is arranged and obtains an imaging signal in accordance with the received light intensity of these optical sensors.
According to this configuration, since the multiline optical sensor is inexpensive, the security sensor can be configured at low cost.

A security sensor according to claim 10 of the present invention is the security sensor according to any one of claims 1 to 9, wherein the determination means is connected to an alarm device for notifying any one of lighting, blinking, display, and sound. The determination means controls the alarm device to be activated when it is determined to be the specific subject, and to control the alarm device not to be operated when it is determined that the specific subject is not the specific subject.
According to this configuration, when the specific subject is a human body, the alarm device can be reliably operated when a person other than the human body enters.

  As described above, according to the present invention, it is possible to provide a security sensor that appropriately detects a human body with an inexpensive configuration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals, and description of the overlapping parts will be omitted as appropriate.
(First embodiment)
FIG. 1 is a block diagram showing the configuration of the security sensor according to the first embodiment of the present invention.
The security sensor 10 shown in FIG. 1 includes an image sensor 11 for visible light, a distance sensor 12, A / D converters 13 and 14, an occupation ratio calculator 15a, a distance calculator 15b, and an actual size calculator 15c. The determination unit 16 is connected to an alarm device 17.

  The image sensor 11 receives visible light in a visual field 18 at a predetermined angle through a lens by an imaging device such as a CCD (Charge Coupled Devices) or a CMOS (Complementary Metal-Oxide Semiconductor), thereby causing an object 19 in the visual field 18. Image. The distance sensor 12 uses a phase difference detection type passive multiline distance sensor (multiline optical sensor) for a camera. The multi-line optical sensor receives an optical signal received by a pair of lenses by an image sensor, and calculates a distance from the distance sensor to a subject based on a difference between the two images. By increasing the number of lines of the multi-line optical sensor and the number of pixels per line, it is possible to perform distance measurement over a wide range and at a plurality of arbitrary points.

Here, the multiline optical sensor 50 will be described with reference to FIGS. 2 and 3.
The multi-line optical sensor 50 uses a distance measuring device already filed by the present applicant. The multi-line optical sensor 50 forms an image of an object 19 as a subject on a photosensor array through two lenses, and is obtained by this imaging 2. One image signal is output, and the distance from the two image signals to the object 19 can be obtained.

  The distance can be obtained based on triangulation, and the principle of triangulation will be described first with reference to FIG. The light of the object 19 (indicated by an arrow for convenience) is formed as subject images 56 and 57 on the optical sensor arrays 53 and 54 by the lenses 51 and 52. Points G and H are intersections of light beams (optical axes 58 and 59) passing through the center points C and D of the lenses 51 and 52 from the infinity front and the optical sensor arrays 53 and 54, respectively.

The distance between the point G and the point H is B, and the distance between the optical sensor arrays 53 and 54 and the lenses 51 and 52 is fe. Further, the deviations of the subject images 56 and 57 from the optical axes 58 and 59 are assumed to be X1 and X2. The length obtained by adding X1 and X2 is X. X is usually called a phase difference. Here, since the triangle ACE and the triangle CFG and the triangle AED and the triangle DHI are similar to each other, the distance d to the object 19 can be obtained by the following equation (1).
d = B · fe / (X1 + X2) = B · fe / X (1)
The phase difference X is two images based on the case where the object 19 as a subject is at infinity, that is, when the two subject images 56 and 57 are at the intersections of the optical axes 58 and 59 of the lenses 51 and 52 and the optical sensor array. The relative transition of. Since B and fe are constants, the distance d can be obtained by detecting the phase difference X.

  Further, as shown in FIG. 3, the multi-line photosensor 50 has a pair of photosensor circuit arrays (FIG. 3 shows an example of three pairs of 130a and 130b, 130c and 130d, and 130e and 130f). Are arranged in pairs in the vertical direction yn. Note that a part of the optical sensor circuit array 130a and a part of 130b, a part of 130c and a part of 130d, a part of 130e and a part of 130f are respectively provided in the optical sensor arrays 53 and 54 shown in FIG. Equivalent to. Although detailed explanation is omitted, as described in Japanese Examined Patent Publication No. 3-67203, the positions of the above-mentioned parts of the optical sensor circuit arrays 130a and 130b, 130c and 130d, and 130e and 130f If the arrays 53 and 54 are arranged so as to be shifted from the position shown in FIG. 2 up and down in FIG. 2, the distance in the oblique direction other than the front surface (the same direction as the optical axes 58 and 59) can be measured. That is, if the optical sensor circuit arrays 130a and 130b, 130c and 130d, 130e and 130f are divided and subdivided, and the principle of triangulation is applied to each pair of subdivided photosensor arrays, A two-dimensional distance distribution can be obtained. Reference numerals 151a, 151b, 152a, 152b, 153a, and 153b denote optical sensor arrays (light receiving units), and reference numerals 154a, 154b, 155a, 155b, 156a, and 156b denote integration circuit arrays (amplifying units).

  More specifically, in the multi-line photosensor 50, the integration circuit arrays 155a and 155b are arranged between the upper photosensor arrays 151a and 151b and the middle photosensor arrays 152a and 152b arranged adjacent to each other. It has become. Similarly, an integrating circuit array is also arranged between the middle and lower photosensor arrays. Although FIG. 3 shows an example in which three pairs of optical sensor circuit arrays are arranged, the number is not limited to three pairs, and more photosensor circuit arrays may be arranged. 5 pairs or more are preferable, and more preferably 10 to 20 pairs.

  According to the distance sensor 12 using such a multiline optical sensor 50, the distance of a location corresponding to an arbitrary point in the field of view 18 of the image sensor 11 can be accurately measured by the single distance sensor 12. . That is, a pair of analog imaging signals obtained by imaging an arbitrary point by the distance sensor 12 is converted into a digital signal by the A / D conversion unit 14, and these are input to the distance calculation unit 15b. The unit 15b calculates the distance from the phase difference between the two digital signals to an arbitrary point. Furthermore, distance distribution information is obtained by calculating distances for a plurality of points in the field of view.

The calculated distance is a distance from the distance sensor 12 to an arbitrary point. If the positional relationship between the distance sensor 12 and the image sensor 11 is known, the image sensor 11 can be simply described as described below. The distance from any point to any point can be calculated.
That is, in order to measure the distance of the object 19 in the visual field 18 of the image sensor 11 with the distance sensor 12, the distance sensor 12 is installed as close as possible to the image sensor 11, and the optical axis of the image sensor 11 and the light of the distance sensor 12 are measured. By making the axes parallel, the visual field 18 of the image sensor 11 and the visual field 20 of the distance sensor 12 are made substantially the same. Thereby, it becomes easy to convert the distance from the distance sensor 12 measured by the distance sensor 12 to the object 19 into the distance from the image sensor 11 to the object 19. In this conversion, information on the positional relationship between the distance sensor 12 and the image sensor 11 is previously stored in the internal storage circuit in the distance calculation unit 15b, and the distance from the distance sensor 12 to the object 19 is calculated as described below. After you ask.

Further, the image sensor 11 and the distance sensor 12 previously image a state in which no human body has entered the visual fields 18 and 20, and use this as an initial state in each of the internal storage circuits of the occupation ratio calculation unit 15a and the distance calculation unit 15b. Remember. And it calculates using the signal imaged with the image sensor 11 and the distance sensor 12 as follows.
Either one or both of the image sensor 11 and the distance sensor 12 is constantly imaged repeatedly, and the object 19 enters the field of view 18 and 20 of the image sensor 11 and / or the distance sensor 12, and the image sensor 11 and the distance sensor 12 The occupation ratio calculation unit 15a and the distance calculation unit 15b determine that either one or both of the states are different from the initial state.

At this time, in the distance calculation unit 15b, the distance from the distance sensor 12 measured by the distance sensor 12 to the object 19 is obtained, and this distance information is stored as information on the positional relationship between the image sensor 11 and the distance sensor 12. Is converted into distance information X that is a distance from the image sensor 11 to the object 19 indicated by an arrow in FIG.
In the occupation ratio calculation unit 15a, the shape of the object 19 and the area ratio occupied by the object 19 in the visual field 18 (this is referred to as an occupation ratio R) are calculated from the contour of the object 19 captured by the image sensor 11. Here, for example, it is assumed that the number of pixels of the image sensor 11 is 4 million pixels (2000 pixels × 2000 pixels), and the number of pixels in the area where the object 19 is imaged is 400,000 pixels. In this case, the ratio of the object 19 to the entire visual field of the image sensor 11 is 1/10.
The occupation ratio R = 1/10 and the distance information X from the image sensor 11 to the object 19 are input to the actual size calculation unit 15c.

  As shown in FIG. 1, the actual size calculation unit 15 c stores the viewing angle θ of the image sensor 11 in the internal storage circuit in advance, and the viewing angle θ, the distance information X input above, the occupation ratio R, As will be described later, the actual area S of the object 19 is obtained. Further, information on the pixel arrangement of the area in which the object 19 is imaged in the image sensor 11 (for example, the number of pixels in the vertical direction of the area) can be set in the vertical and horizontal directions of the object 19 and in any direction as necessary. The shape information P is obtained by obtaining each length, and the actual size information E of the object 19 is obtained from the shape information P and the actual area S.

That is, when the actual area S of the object 19 is obtained, since the distance from the image sensor 11 to the object 19 shown in FIG. 1 is known as X from the distance information X, the vertical and horizontal lengths of the visual field 18 of the image sensor 11 are Each is 2X × tan θ, and the area in the visual field 18 is a distance 4X ² tan ² θ (when the image sensor is square. When the image sensor is rectangular, 4X ² tan θ ₁ × tan θ ₂ , where θ ₁ and θ ₂ are Viewing angle in the vertical and horizontal directions respectively.) By multiplying this result by the occupation ratio R = 1/10, the real area S = 0.4X ² tan ² θ of the object 19 is obtained.

Further, as described above, the shape information P is obtained by obtaining the length of the object 19 in the vertical direction, the horizontal direction, and the arbitrary direction from the number of pixels in the vertical direction, the horizontal direction, and the arbitrary direction of the image sensor 11. . Then, the actual size information E of the object 19 is obtained from the shape information P and the actual area S, and this is input to the determination unit 16.
The determination unit 16 stores, as comparison information, values in a predetermined range in consideration of the area, shape, and size indicating the size of the human body, and the actual area and / or actual size information E of the input object 19 is compared information. If it is within the range, it is determined that the object 19 is a human body, and if it is out of the range, it is determined that it is other than a human body. The determination unit 16 may determine using both data of the actual area of the object 19 and the actual size information E, or may determine using only information on one side, for example, the actual area of the object 19. Then, the determination unit 16 controls the alarm device 17 to notify the abnormality by a light or an alarm when it is determined to be a human body, and does not operate when it is determined that it is other than a human body.

  As described above, according to the security sensor 10 of the first embodiment, the image sensor 11 that captures an image of the object 19 that is a subject in the field of view through the lens and the distance to the object 19 is at least a pair of lenses. And a distance sensor 12 that obtains a plurality of imaging signals by imaging with an imaging element via the. Then, the distance calculation unit 15b obtains the distance from the distance sensor 12 to the object 19 using the phase difference of the plurality of imaging signals obtained by the distance sensor 12, and the distance is calculated from the image sensor 11 and the distance sensor 12. Is converted into distance information from the image sensor 11 to the object 19 using the positional relationship information.

  The occupation ratio calculation unit 15 a obtains an occupation ratio that is the ratio of the area of the object 19 imaged by the image sensor 11 to the entire imaging field of the image sensor 11. Further, the actual size calculation unit 15c calculates the area of the entire field of view of the image sensor 11 using the viewing angle of the image sensor 11 and the distance information, and multiplies this area by the occupation ratio to determine the actual area of the object 19, The shape information of the object 19 is obtained from the number of pixels picked up by the image sensor 11, and the actual size information of the object 19 is obtained from the shape information and the actual area. Then, the determination unit 16 compares the actual area and / or actual size information of the object 19 with comparison information indicating the size of the specific object 19 by a value within a predetermined range, whereby the captured object 19 is the specific object. Whether or not 19 is determined.

  That is, the actual area and / or actual size information of the object 19 that is the object 19 captured by the image sensor 11 is obtained, and the actual area and / or actual size information of the object 19 is compared with the comparison information that is a threshold value. Since it is determined whether or not the imaged object 19 is a specific object 19, when the security sensor 10 is installed in a security area such as a building where a security measure is required, a person (object 19) can be accurately identified when invading.

  As a result, it is possible to reduce malfunctions of the alarm device 17 and the like due to the intrusion of other than the human body. In the conventional security sensor, since the size of the object 19 cannot be properly identified according to the distance from the sensor, a small animal such as a dog or a cat, a car larger than a person, or the like entering the sensing area However, it was detected, and the object 19 could not be accurately identified depending on the angle of the object 19 with respect to the image sensor 11.

  Further, the image sensor 11 and the distance sensor 12 are arranged so that the optical axes of the lenses are parallel and close to each other. Thus, the distance calculation unit 15b converts the distance from the distance sensor 12 to the object 19 into distance information from the image sensor 11 to the object 19 using information on the positional relationship between the image sensor 11 and the distance sensor 12. In this case, this calculation can be simplified.

Since the configuration of the security sensor 10 can be configured with inexpensive parts including the image sensor 11 and the distance sensor 12, the A / D conversion units 13 and 14, the calculation units 15a to 15c, and the determination unit 16, it has already been described. Therefore, it is not expensive as in the configuration of Patent Document 2.
Therefore, in this Embodiment, the crime prevention sensor 10 which can detect a human body appropriately with an inexpensive structure can be provided.
In addition, the number of distance measuring points of the distance sensor 12 may be changed according to the imaging information obtained by the image sensor 11. In this case, if the number of distance measuring points of the distance sensor 12 is reduced, the distance calculation time in the distance calculation unit 15b can be shortened.

(Second Embodiment)
FIG. 4 is a block diagram showing a configuration of a security sensor according to the second embodiment of the present invention.
The security sensor 30 shown in FIG. 4 includes a pyroelectric infrared sensor 31, a distance sensor 12, A / D conversion units 13 and 14, and a determination unit 32. The determination unit 32 is an alarm device. 17 is connected.
The feature of the present embodiment is that the pyroelectric infrared sensor 31 and / or the distance sensor 12 detects the intrusion of the object 19, and the pyroelectric infrared sensor 31 detects the amount of infrared radiation in the field of view 33 as a charge, and the distance The sensor 12 detects the position and distance of the object. The intruding object 19 is a human body or a small animal based on the amount of infrared radiation detected by the pyroelectric infrared sensor 31 and the distance to the object 19 obtained from the distance sensor 12. .

  In order to measure the distance of the object 19 in the visual field 33 of the pyroelectric infrared sensor 31 with the distance sensor 12, the distance sensor 12 is installed as close as possible to the pyroelectric infrared sensor 31. The field of view 33 of the pyroelectric infrared sensor 31 and the field of view 20 of the distance sensor 12 are made substantially the same. This facilitates conversion of the distance from the distance sensor 12 measured by the distance sensor 12 to the object 19 into the distance from the pyroelectric infrared sensor 31 to the object 19.

  In this conversion, information on the positional relationship between the distance sensor 12 and the pyroelectric infrared sensor 31 is stored in advance in the internal storage circuit in the distance calculation unit 15b, and from the distance sensor 12 to the object 19 as described below. After finding the distance. The distance sensor 12 images in advance a state in which no human body has entered the visual field 20, and stores this in the internal storage circuit of the distance calculation unit 15b as an initial state.

Then, when the intrusion of the object 19 is detected by the pyroelectric infrared sensor 31 and / or the distance sensor 12, the distance calculation unit 15b calculates the distance from the distance sensor 12 to the object 19, and the pyroelectric infrared is calculated from the distance. The distance from the sensor 31 to the object 19 is calculated. The calculated distance information X is input to the determination unit 32.
Further, the infrared radiation amount information Y obtained by converting the infrared radiation amount obtained by the pyroelectric infrared sensor 31 into a digital signal by the A / D conversion unit 13 is input to the determination unit 32.

  In the determination unit 32, a threshold for determining whether or not a human body is set according to the distance from the pyroelectric infrared sensor 31 to the object 19. Both the upper limit and the lower limit are set for the threshold value, and the determination unit 32 determines that the object 19 exceeding the upper limit threshold is an object having a larger amount of infrared radiation than the human body, and that the object less than the lower limit threshold is infrared radiation than the human body. It is determined that the object 19 is a small amount, and it is determined whether the object is a human body. Further, in order to compensate the direction dependency of the sensitivity of the pyroelectric infrared sensor 31, information about the direction (angle) of the object 19 is transmitted from the distance sensor 12 to the determination unit 32, and the determination unit 32 changes the threshold value based on the information. You may do it.

  That is, the determination unit 32 determines a threshold value according to the distance from the pyroelectric infrared sensor 31 obtained by the distance sensor 12 to the object 19 and determines whether or not the intruding object 19 is a human body. The determination unit 16 controls the alarm device 17 that notifies the abnormality by a light or an alarm when the object 19 is determined to be a human body, and does not operate when it is determined that the object 19 is not a human body.

  As described above, according to the security sensor 30 of the second embodiment, at least a pair of the pyroelectric infrared sensor 31 that senses the infrared radiation amount of the object 19 that is the subject in the field of view by the charge and the distance to the object 19. And a distance sensor 12 that obtains a plurality of imaging signals by imaging with an imaging element through the lens. Then, the distance calculation unit 15b obtains the distance from the distance sensor 12 to the object 19 using the phase difference of the plurality of imaging signals obtained by the distance sensor 12, and this distance is compared with the pyroelectric infrared sensor 31. Using the positional relationship information with the sensor 12, the distance information from the pyroelectric infrared sensor 31 to the object 19 is converted. The determination unit 32 sets an upper limit threshold and a lower limit threshold according to the distance information, determines that the infrared radiation detected by the pyroelectric infrared sensor 31 is not a human body when the upper limit threshold is exceeded, and is less than the lower limit threshold. In the case of, it was determined to be a human body.

  Thus, when the pyroelectric infrared sensor 31 or the distance sensor 12 detects the intrusion of the object 19, the pyroelectric infrared sensor 31 detects the amount of infrared radiation in the field of view, and the distance sensor 12 detects the position of the object 19 and Detect distance. It is possible to determine whether the intruding object 19 is a human body or a small animal from the amount of infrared radiation obtained by the pyroelectric infrared sensor 31 and the distance to the object 19 obtained from the distance sensor 12. It becomes.

The pyroelectric infrared sensor 31 and the distance sensor 12 are arranged so that the optical axes of the lenses are parallel and close to each other. Thus, the distance calculation unit 15b determines the distance from the distance sensor 12 to the object 19 from the pyroelectric infrared sensor 31 to the object 19 by using information on the positional relationship between the pyroelectric infrared sensor 31 and the distance sensor 12. This calculation can be simplified when converting into the distance information.
Further, the number of distance measuring points of the distance sensor 12 may be changed according to image information obtained by infrared detection of the object 19 by the pyroelectric infrared sensor 31. In this case, if the number of distance measuring points of the distance sensor 12 is reduced, the distance calculation time in the distance calculation unit 15b can be shortened.

In addition, as an application example of the second embodiment, as shown in FIG. 5, the crime prevention sensor 40 includes a pyroelectric infrared sensor 31 and a direction adjustment unit 41, and the distance calculation unit 15 b includes the object 19. The direction may be determined, and the direction adjustment unit 41 may be controlled so that the center of the visual field of the pyroelectric infrared sensor 31 is directed in this direction.
In this case, the directivity of the pyroelectric infrared sensor 31 can be increased and the sensitivity can be increased. Alternatively, the sensitivity can be uniform anywhere in the detection range of the security sensor 40.

It is a block diagram which shows the structure of the security sensor which concerns on the 1st Embodiment of this invention. It is a principle diagram of distance measurement by a multiline optical sensor based on the principle of triangulation. It is a figure which shows the structure of a multiline optical sensor. It is a block diagram which shows the structure of the security sensor which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the security sensor which concerns on the application example of 2nd Embodiment. It is a figure for demonstrating the malfunction of an image sensor.

Explanation of symbols

10, 30, 40 Security sensor 11 Visible light image sensor 12 Distance sensor 13, 14 A / D converter 15a Occupancy ratio calculator 15b Distance calculator 15c Actual size calculator 16, 32 Judgment unit 17 Alarm device 18 Field of view of image sensor 19 Object 20 Field of View of Distance Sensor 31 Pyroelectric Infrared Sensor 33 Field of View of Pyroelectric Infrared Sensor 41 Direction Adjustment Unit

Claims (10)

In a security sensor that uses an image sensor that captures a subject in the field of view with an image sensor via a lens, and determines whether or not the subject captured by the image sensor is a specific subject,
A distance sensor that obtains a plurality of imaging signals by imaging the distance to the subject with an imaging device via at least a pair of lenses;
A distance from the distance sensor to the subject is obtained using a phase difference between a plurality of imaging signals obtained by the distance sensor, and the distance is obtained using information on a positional relationship between the image sensor and the distance sensor. Distance calculating means for converting into distance information which is a distance from the image sensor to the subject;
An occupancy ratio calculating means for determining an occupancy ratio that is a ratio of the area of the subject imaged by the image sensor to the entire imaging field of view of the image sensor;
From the viewing angle of the image sensor and the distance information, obtain the actual area of the entire field of view of the image sensor at the distance of the distance information, and multiply the actual area by the occupation ratio to obtain the actual area of the subject. Actual size calculation means;
Determination means for determining whether or not the captured subject is a specific subject by comparing the actual area of the subject with comparison information indicating the size of the specific subject as a value within a predetermined range. Security sensor characterized by. The actual size calculation means further obtains the shape information of the subject from the pixel arrangement information of the area where the subject is imaged in the image sensor, and obtains the actual size information of the subject from the shape information and the actual area. Have
The determination means compares at least one of the actual area of the subject and the actual size information of the subject with comparison information indicating the size of the specific subject with a value within a predetermined range, whereby the captured subject is specified. The security sensor according to claim 1, wherein it is determined whether or not the subject is a subject.   The security sensor according to claim 1 or 2, wherein the image sensor and the distance sensor are arranged such that optical axes of the lenses are parallel and close to each other. The security sensor according to any one of claims 1 to 3, wherein the number of distance measuring points of the distance sensor is changed according to imaging information obtained by the image sensor.
In a security sensor that uses a pyroelectric infrared sensor that senses the amount of infrared radiation of a subject in the field of view with a charge, and determines whether or not the subject sensed by this pyroelectric infrared sensor is a specific subject,
A distance sensor that obtains a plurality of imaging signals by imaging the distance to the subject with an imaging device via at least a pair of lenses;
A distance from the distance sensor to the subject is obtained using a phase difference of a plurality of imaging signals obtained by the distance sensor, and this distance is obtained as information on a positional relationship between the pyroelectric infrared sensor and the distance sensor. A distance calculating means for converting into distance information that is a distance from the pyroelectric infrared sensor to the subject;
When an upper limit threshold and a lower limit threshold are set according to the distance information obtained by the distance calculation means, and the amount of infrared radiation detected by the pyroelectric infrared sensor exceeds the upper limit threshold or falls below the lower limit threshold A security sensor comprising: a determination unit that determines that the subject is not a specific subject, and determines that the subject is a specific subject in other cases.   The security sensor according to claim 5, wherein the pyroelectric infrared sensor and the distance sensor are arranged such that optical axes of the lenses are parallel and close to each other.   The security sensor according to claim 5 or 6, wherein the number of distance measuring points of the distance sensor is changed in accordance with image information obtained by infrared detection of a subject by the pyroelectric infrared sensor. A direction adjusting means for changing the direction of the pyroelectric infrared sensor is provided, and the distance calculation unit performs a calculation for determining the direction in which the subject exists, and the center of the field of view of the pyroelectric infrared sensor is calculated in the calculated direction. The security sensor according to any one of claims 5 to 7, wherein the direction adjusting means is controlled so that the direction of the security sensor is directed.   The distance sensor is a multi-line optical sensor in which a plurality of a pair of one-dimensional optical sensor arrays on which the subject is imaged through two lenses are arranged and an imaging signal is obtained according to the received light intensity of these optical sensors. The security sensor according to any one of claims 1 to 8.   An alarm device for notifying any one or all of lighting, blinking, display, and sound is connected to the determination means, and when the determination means determines that the specific subject, the alarm device is activated to The security sensor according to any one of claims 1 to 9, wherein the alarm device is controlled not to operate when it is determined that the subject is not a subject.

Images