JP2003227873A - Monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring system by which an object to be monitored inside an object region can be monitored precisely and by which the object to be monitored can be processed simply and at a high speed. <P>SOLUTION: The monitoring system 1 is provided with a distance sensor 11 used to measure a distance up to the object 2 to be monitored; a distance-information storage part 25 used to store distance information acquired by the distance sensor 11; and a decision part 22 in which whether the object 2 to be monitored is moved or not is decided on the basis of the distance information stored in the storage part 25. The distance sensor 11 has a light irradiation means 31a used to irradiate beam light at the object 2 to be monitored; an image-information optical system 37a used to image-form the beam light reflected by the object 2 to be monitored; and a light receiving face 38 which is arranged near an image-formation position by the optical system 37a and which is divided into a plurality of light receiving regions 38a, 38b. The monitoring system 1 has a positional-information output device 39a constituted in such a way that intensities of the beam light incident on the respective light receiving regions are compared with each other and that beam-light image-formation positional information corresponding to the distance information up to the object 2 to be monitored is output. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance system, and more particularly to a surveillance system for monitoring the presence or absence of movement of an object or a person in a target area.

[0002]

2. Description of the Related Art Conventionally, as a monitoring device for knowing an abnormality without damaging the privacy of a patient in a hospital room or a toilet, a bright spot is projected on a monitoring target area to capture an image of the area. There is proposed a device that detects a height change of a target area by a position change of a bright spot in a captured image from a reference position and monitors the presence or absence of an object or a person in the target area and the presence or absence of movement.

[0003]

However, according to the conventional device as described above, the monitoring of the target area requires processing of the captured image, which requires a large amount of calculation and requires a long processing time. , Needed complex equipment.

Therefore, an object of the present invention is to provide a monitoring system which can not only accurately monitor the target area but also can perform simple and high-speed processing.

[0005]

In order to achieve the above object, a monitoring system 1 according to the invention according to claim 1 has a monitoring target 2 as shown in FIGS. 1, 6, 15, and 17, for example. A distance sensor 11 for measuring a distance to the distance information storage unit 2 for storing distance information acquired by the distance sensor 11.
5; and a determination unit 22 that determines whether or not the monitored object 2 moves based on the distance information stored in the distance information storage unit 25; the distance sensor 11 irradiates the monitored object 2 with a beam of light. A light irradiation unit 31a, an image forming optical system 37a for forming an image of the beam light reflected by the monitoring target 2, and a light beam reflected by the image forming optical system 37a arranged near the image forming position by the image forming optical system 37a. A light receiving surface 38 divided into a plurality of light receiving regions 38a and 38b; and further, receiving the signal from each of the light receiving regions, and based on the received signal, the intensity of the beam light incident on each of the light receiving regions. It has a position information output device 39a configured to compare with each other and output the light beam imaging position information corresponding to the distance information to the monitored object 2.

With this configuration, the distance sensor 11
Since the distance information storage unit 25 and the determination unit 22 are provided, the monitoring system 1 that does not need to process an image and can perform high-speed processing can be provided. In addition, the distance sensor 11
Is a beam light irradiation means 31a, an imaging optical system 37a,
Light receiving surface 38 divided into a plurality of light receiving regions 38a, 38b
Since it has, the circuit configuration can be simplified, and the monitoring system 1 can be inexpensive and simple.

In order to achieve the above-mentioned object, a monitoring system 1 according to a second aspect of the present invention has, for example, FIG.
As shown in FIGS. 15 and 17, a distance sensor 11 that measures the distance to the monitored object 2, a distance information storage unit 25 that stores the distance information acquired by the distance sensor 11, and a distance information storage unit 25 that stores the distance information. The distance sensor 11 includes a light irradiator 31b for irradiating the object to be monitored 2 with a beam of light and a light irradiator 31b. Imaging optical system 3 for forming an image of a light beam spot generated on the monitored object 2 by
7b and a light receiving means 36 arranged near the image forming position of the image forming optical system 37b for receiving the light beam from the monitored object 2.
A position information output device 39b configured to output spot position information corresponding to the distance information to the monitored object 2 based on the beam light spot position imaged on the light receiving means 36. Have

With this configuration, the distance sensor 11
Since the distance information storage unit 25 and the determination unit 22 are provided, the monitoring system 1 that does not need to process an image and can perform high-speed processing can be provided. In addition, the distance sensor 11
Has a light irradiation means 31b, an imaging optical system 37b, and a light receiving means 36, and corresponds to the distance information to the monitored object 2 based on the beam light spot position imaged on the light receiving means 36. Since the spot position information is output, the monitoring system 1 can be inexpensive and simple.

Further, as described in claim 3, in the monitoring system 1 according to claim 1 or 2, the distance information storage unit 25 stores the distance information acquired by the distance sensor 11 in time series. The determination unit 22 calculates a distance information difference between the distance information acquired by the distance sensor 11 and the immediately preceding distance information stored in the time series, and calculates the distance information difference and a first predetermined threshold value. Is compared, it is determined that the monitored object 2 has moved when the distance information difference is larger than the first predetermined threshold value, and is monitored when the distance information difference is smaller than the first predetermined threshold value. Object 2 is configured to determine that it is stationary.

With this configuration, the distance information difference between the distance information acquired by the distance sensor 11 and the immediately preceding distance information stored in time series is calculated, and the distance information difference and the first predetermined threshold value are calculated. By comparison, when the distance information difference is larger than the first predetermined threshold value, it is determined that the monitoring target object 2 has moved, and when the distance information difference is smaller than the first predetermined threshold value, the monitoring target object 2 is determined. Since it is determined that the object is stationary, it is resistant to noise mixed in the distance information, and the presence or absence of movement of the monitored object 2 can be accurately determined.

Further, any one of claims 1 to 3
The monitoring system 1 described in the paragraph 1 is further preferably provided with a plurality of distance sensors 11. With this configuration, by providing the plurality of distance sensors 11, it is possible to accurately determine whether or not the monitored object 2 is moving.

Further, as described in claim 4, in the monitoring system 1 according to claim 3, the judgment unit 22 compares the distance with the first predetermined threshold value for each of the plurality of distance sensors 11. The difference between the number of times when it is determined that there is motion within a certain period and the number of times when it is determined to be stationary and the number of times when it is stationary is determined, and the number difference is larger than a second predetermined threshold value. It may be configured to determine that the monitoring target point 6 of the sensor has moved.

With this configuration, for example, noise is mixed in the signal from the distance sensor 11, so that the monitoring target point 6 which does not actually move is not erroneously determined to have moved, and is highly reliable. The monitoring system 1 can be provided.

Further, as described in claim 5, in the monitoring system 1 described in claim 4, the determination unit 22 determines that the number of the monitoring target points 6 determined to have the motion and the number of the stationary points. A difference from the determined number of monitoring target points 6 is obtained, and based on the difference in the number of monitoring points, it is configured to determine whether the monitoring target object 2 is moving or stationary as a whole.

With this configuration, it is determined whether the monitored object 2 is moving or stationary as a whole, so that the monitoring system 1 having high reliability can be provided.

Further, in the above-mentioned invention, the judgment unit 22 is configured so that the distance sensor 1 with respect to the surveillance area surface 3 where the surveillance object 2 exists.
2 based on the relative position of 1 and the distance measuring direction of the distance sensor 11 relative to the monitoring area surface 3.
The height from the monitoring area surface 3 may be calculated.

Further, in the above invention, the judging section 22 may judge the posture of the monitored object 2 based on the height. Further, the height is an average value of a plurality of distance information acquired by the distance sensor 11 in time series, and the average value is an average of distance information generated within each time interval at a certain fixed time interval. It may be a value or a moving average value for a certain number of pieces of distance information.

With this configuration, the determination unit 22 can calculate the height of the monitored object 2 from the monitoring area surface 3 and determine the posture of the monitored object 2 based on the height, and therefore the accuracy can be improved. A high monitoring system 1 can be provided.

Further, in the above-mentioned invention, the judgment unit 22 is configured so that the distance sensor 1 with respect to the surveillance area surface 3 where the surveillance object 2 exists.
2 based on the relative position of 1 and the distance measuring direction of the distance sensor 11 relative to the monitoring area surface 3.
The depth from the distance sensor 11 in the direction parallel to the monitoring area surface 3 may be calculated.

Further, in the above invention, the height and the depth are average values of a plurality of distance information acquired by the distance sensor 11 in time series, and the average value is each time at a certain fixed time interval. Average value of distance information generated within the interval, or
It is a moving average value for a certain number of pieces of distance information.

Further, in the above-mentioned invention, the judgment unit 22 may judge the posture of the monitored object 2 based on the height and / or the depth.

With such a configuration, the determination unit 22 causes the height sensor 2 and the distance sensor 1 of the monitoring target 2 from the monitoring area surface 3.
Since the depth from 1 in the direction parallel to the monitoring area surface 3 can be calculated and the posture of the monitored object 2 can be determined based on both or either of the height and the depth, the monitoring system 1 with high accuracy can be obtained. Can be provided.

Further, in the above invention, it is preferable that the monitoring target points 6 are arranged in two or more rows in a direction perpendicular to the main moving direction of the monitoring target 2.

In order to achieve the above object, a monitoring system 100 according to a sixth aspect of the invention is installed corresponding to a monitoring target point 6 to be monitored, as shown in FIGS. 1, 4 and 6, for example. A distance sensor, which is a distance sensor 11 that measures a distance to a corresponding monitoring target point 6; a reference distance storage unit 125 that stores reference distance information to be compared with the distance information acquired by the distance sensor 11. A distance comparing means 122 for comparing the distance information acquired from the distance sensor 11 with the reference distance information; and a distance comparing means 12
The monitoring unit 128 that monitors the monitoring target 2 existing between the monitoring target point 6 and the distance sensor 11 based on the comparison result of 2; the distance sensor 11 irradiates the monitoring target 2 with a light beam. The light irradiating means 31a, the image forming optical system 37b for forming an image of the beam light reflected by the monitored object 2, and the reflected beam light arranged near the image forming position of the image forming optical system 37b. , A plurality of light receiving regions 38a, 3
And a light receiving surface 38 divided into 8b; further, receiving signals from the respective light receiving regions, comparing the intensities of the light beams incident on the respective light receiving regions based on the received signals, and monitoring It has a position information output device 39a configured to output the light beam imaging position information corresponding to the distance information to the object 2.

With this configuration, the distance sensor 11
A reference distance storage unit 125, a distance comparison unit 122,
Since the monitoring unit 128 is provided, the reference distance information to be compared with the distance information acquired by the distance sensor 11 is stored, the distance information acquired from the distance sensor 11 is compared with the reference distance information, and the comparison result is obtained. Based on this, by monitoring the monitoring target 2 existing between the monitoring target point 6 and the distance sensor 11, it is possible to provide the monitoring system 100 that can perform high-speed processing and is inexpensive. In addition, the distance sensor 11
Is a beam light irradiation means 31a, an imaging optical system 37a,
Light receiving surface 38 divided into a plurality of light receiving regions 38a, 38b
Since it has, the circuit configuration can be simplified and the monitoring system 100 can be inexpensive and simple.

Further, the monitoring system 10 according to claim 6
It is more preferable that 0 includes a plurality of distance sensors 11.

In the above invention, the distance measuring direction of the distance sensor 11 may be inclined with respect to the vertical direction.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same or corresponding members are designated by the same reference numerals or similar reference numerals, and redundant description will be omitted.

FIG. 1 is a schematic perspective view of a monitoring system 100 according to the first embodiment of the present invention. In the figure, the monitored object 2 exists on the floor surface 3. Floor 3 on the XY axes
The Cartesian coordinate system XYZ is set so as to be placed inside. A wall 4 is formed perpendicular to the floor surface 3, that is, on the YZ plane. The monitoring target 2 is a person in this embodiment.

On the other hand, on the wall 4 in the figure, there is installed a casing 10 including a plurality of distance sensors 11 for measuring the distance of the person 2, and the casing 10 has a plurality of distances. Sensors 11 are installed corresponding to a plurality of monitoring target areas 6 (hereinafter referred to as monitoring areas 6) as a plurality of monitoring target points. Further, the distance measuring direction of the distance sensor 11 may be inclined with respect to the vertical direction. Further, in the present embodiment, the housing 10 (distance sensor 11) is installed on the wall, but if a ceiling is present, it may be installed on the ceiling, and the installation location may be appropriately determined according to the purpose and specifications of the monitoring system. . Each measured distance of the plurality of monitoring areas 6 by the plurality of distance sensors 11 forms a measured distance pattern, and the corresponding reference distance forms a reference distance pattern.

Further, as shown in FIG. 2, for example, when the monitoring system 100 is installed in a toilet, the housing 10 may be installed on the ceiling. Further, in the figure, the monitoring area 6
Are arranged in 2 × 5, but the number to be installed may be appropriately determined as described later.

The monitoring area 6 will be described with reference to an arrangement example of the monitoring area 6 in the schematic plan view of FIG. Figure 3
(A) is an example in which a plurality of monitoring areas are arranged so as not to overlap adjacent monitoring areas. In this case, for example, as shown in the figure, a plurality of monitoring areas are provided in the monitoring zone 60, which is a place to be monitored, from the right column in the drawing, monitoring areas 61, 62,
63, 64, 65, 66, 67, 68, 69 (hereinafter, simply referred to as monitoring area 6 when the monitoring areas are not distinguished)
However, they are arranged in a grid pattern so that they do not overlap each other. The number to be arranged is 3 rows and 3 columns (3 × 3) here, but may be appropriately determined depending on conditions such as the place to be monitored and the person 2, and may be, for example, 2 × 1 or 3 × 2, 3 × 5. . When a plurality of monitoring areas 6 are arranged in this way, even when an irradiation type sensor that measures a distance by irradiating light, for example, is used as the distance sensor 11, the distance sensors 11 corresponding to the adjacent monitoring areas 6 are As described later, it is not necessary to control the irradiation so that the irradiation is not performed simultaneously, and the monitoring system 100 can have a simpler configuration.

Further, as shown in the arrangement example of the monitoring areas 6 in the schematic plan view of FIG. 3B, the adjacent monitoring areas 6 may overlap with each other. This makes it possible to reduce the blind spots in the monitoring zone 60, which is effective for more accurate monitoring. At this time, when the irradiation type sensor is used as the distance sensor 11, the distance sensors 11 corresponding to the overlapping monitoring areas 6 do not affect each other.
It is necessary to control not to irradiate at the same time. this is,
When, for example, irradiation light is emitted from a plurality of distance sensors 11 at the same time, the irradiation light emitted from another distance sensor 11 is mixed with the irradiation light that should originally be received, which makes it difficult to measure the distance of the monitoring area 6. This is because. The control in the case shown in this figure will be described in detail later. Further, when the wavelengths of the light beams projected by the distance sensors 11 are made different for each sensor as described later, it is not necessary to control so that the adjacent target points 5 do not irradiate at the same time even if they overlap. . Further, when the distance sensor 11 is provided with a band-pass filter which will be described later, it is not necessary to control so that the target points 5 adjacent to each other do not irradiate at the same time.

An example of the configuration of the monitoring system 100 will be described with reference to FIG. The monitoring system 100 includes a housing 10 in which a plurality of distance sensors 11 are installed and an arithmetic unit 120.
It is configured to include and. And a plurality of distance sensors 11
Is connected to the arithmetic device 120 and is configured to be able to acquire distance information from each distance sensor 11. The distance information may be acquired from each distance sensor 11 in time series. The arithmetic device 120 is typically a personal computer or a microcomputer. Further, although the distance sensor 11 and the arithmetic unit 120 are shown as separate bodies in the figure, they may be integrally configured.

Here, the distance information is, for example, an output value from the distance sensor 11 before actually calculating the distance,
It may be the distance to the target person 2 itself. The reference distance information is, for example, an output value from the distance sensor 11 before actually calculating the reference distance, but may be the reference distance itself. Further, the reference distance may be a distance at a time point in the past of the monitoring time point, and is typically a distance in the background when the person 2 does not exist in the monitoring area 6, but is not limited thereto, and for example, periodically. The distance may be one frame before when the distance is detected.

Further, typically, the distance sensor 11 is the housing 1
However, as shown in the schematic view of FIG. 5, the housing 10 may be installed with a curve. By installing in this way, a wide monitoring zone 60 can be easily secured even with a small housing 10 '. Further, when the irradiation type sensor is used as the distance sensor 11 as described above, the distance sensor 11 corresponding to the adjacent monitoring areas 6 is used.
Since the monitoring areas 6 do not easily overlap with each other even with a small housing 10 ', mutual influence of the distance sensors 11 can be easily eliminated. Further, when the monitoring areas 6 are not overlapped, it is not necessary to include the timing controller 123 described later, and the monitoring system 100 can have a simpler configuration. Further, the housing 10 ′ has the same effect when used in the monitoring system 1 described later.

The arithmetic unit 120 is equipped with a control unit 121, and controls the entire monitoring system 100. Further, the plurality of distance sensors 11 are connected to and controlled by the control unit 121. Further, the control unit 121 is provided with a comparison calculation unit 122 that is a distance comparison unit that compares the distance information acquired from each of the plurality of distance sensors 11 with the reference distance information corresponding to each distance sensor 11. There is. Further, the control unit 121 includes a monitoring unit 128 that monitors the person 2 existing between the monitoring area 6 and the distance sensor 11 based on the comparison result by the comparison calculation unit 122.

The comparison result by the comparison calculation unit 122 is typically acquired in time series, and the movement, position, posture, etc. of the person 2 can be judged by the monitoring unit 128 based on the comparison result. That is, by comparing the reference distance information with the distance information at a certain point in time, it is possible to determine the presence, movement, position, posture, etc. of the person 2. Furthermore, the final determination of the presence, movement, position, posture, etc. of the person 2 is made comprehensively from the determination results corresponding to each of the plurality of distance sensors 11. The movement of the person 2 includes not only the change of the position of the person 2 but also the change of the person 2 standing or sitting. Further, when the monitoring areas 6 overlap, a timing controller 123 is provided as a control device that controls so that the plurality of distance sensors 11 corresponding to the adjacent monitoring areas 6 do not operate simultaneously. The control by the timing controller 123 will be described later in detail.

A storage unit 124 is connected to the control unit 121. In the storage unit 124, a plurality of distance sensors 11
The reference distance storage unit 125 stores the reference distance information to be compared with the distance information acquired from the. In addition, the storage unit 124 can store data such as calculated information.

The control unit 121 also includes a monitoring system 10
An input device 126 for inputting information for operating 0 and an output device 127 for outputting the result processed by the monitoring system 100 are connected. The input device 126 is, for example, a touch panel, a keyboard or a mouse, and the output device 127 is, for example, a display, a printer or an alarm device. In this figure, the input device 126 and the output device 127 are shown.
Although shown as being externally attached to the arithmetic unit 120, it may be incorporated.

As the distance sensor 11 used, there is an infrared irradiation type distance sensor as an irradiation type sensor. An infrared irradiation type distance sensor will be described below with reference to the drawings.

An infrared irradiation type distance sensor 30 (hereinafter referred to as an infrared distance sensor 30) as an example of the distance sensor 11 will be described. Infrared distance sensor 30
Is a so-called active optical sensor. Further, as the infrared distance sensor 30, there are a type using a photo detector (hereinafter referred to as a multi-divided PD) divided into a plurality of light receiving regions and a type using a position detection element (hereinafter referred to as PSD). Hereinafter, the one using the multi-division PD is the infrared distance sensor 30a, and the one using the PSD is the infrared distance sensor 3
It will be described as 0b. Further, when these are not particularly distinguished, they are simply referred to as the infrared distance sensor 30.

First, an infrared distance sensor 30a using a multi-division PD will be described with reference to the block diagram of FIG. The infrared distance sensor 30a includes an infrared light irradiation unit 31a as a light irradiation unit that irradiates the person 2 with a light beam, an infrared light receiving unit 32a, and a sensor control unit 33a that controls the entire infrared distance sensor 30a. ing. In addition, the sensor control unit 33 a includes the control unit 121 of the arithmetic device 120.
It may be provided inside (see FIG. 4).

An infrared LED 34 is provided in the infrared light irradiation section 31a.
a and an irradiation lens 35a are provided, and an infrared LED
The infrared light emitted from 34a is emitted to the person 2 as a thin parallel light beam light through the irradiation lens 35a.
The infrared light receiving section 32a includes a light receiving lens 37a as an image forming optical system that forms an image of the light beam reflected by the person 2.
The multi-division PD 38 is disposed in the vicinity of the image forming position of the light receiving lens 37a and is divided into a plurality of light receiving areas for receiving the beam light reflected by the person 2.
Here, the number of divisions of the multi-division PD 38 will be described as being divided into two (hereinafter referred to as two-division PD 38). Further, the infrared distance sensor 30a receives signals from the respective light receiving areas, compares the intensities of the light beams incident on the respective light receiving areas with each other based on the received signals, and obtains distance information corresponding to the distance to the person 2. It has a position information output unit 39a as a position information output device configured to output the beam light imaging position information corresponding to. The position information output unit 39a is provided in the sensor control unit 33a.

Here, referring to FIGS. 7 and 8, the PD 3 is divided into two parts.
8 will be described. As shown in FIG. 7, two-part PD3
8 is divided into two light receiving areas 38a and 38b (hereinafter, simply referred to as light receiving areas unless otherwise distinguished),
It is placed in parallel on the substrate 38c. The dividing direction is
Moving direction of imaging beam due to distance change (left and right direction in the figure)
Direction approximately perpendicular to. In other words, the divided light receiving regions 38a and 38b are divided so as to be lined up along the moving direction of the imaging beam due to the distance change.

In the light receiving areas 38a and 38b, the light beams reflected by the person 2 and imaged by the light receiving lens 37a (hereinafter referred to as "imaging beams") are imaged over the light receiving areas 38a and 38b, respectively. An electric current is generated in the light receiving area of.

Then, as shown in FIG.
An IV conversion amplifier 39d is connected to each of a and 38b. The current values of the currents generated in the light receiving regions 38a and 38b are respectively the IV conversion amplifier 3
The voltage value is converted by 9d and input to the comparison circuit 39c. The comparison circuit 39c calculates the light beam imaging position information, that is, the distance information by taking these ratios. The IV conversion amplifier 39d and the comparison circuit 39c are both included in the position information output unit 39a. In the case of the two-divided PD 38, the light receiving area of the two-divided PD 38 is smaller than the diameter of the imaging beam (imaging beam diameter) by the two-divided PD 38.
It is preferable to set so that the light receiving area of is large. By doing so, even if the imaging beam diameter increases due to the change in the distance of the object, the imaging beam is split into two PDs 38.
The distance can be measured stably and accurately without chipping from above.

Since the two-division PD 38 generates a current in proportion to the light quantity (intensity) of the image-forming beam, the voltage value output from the light receiving regions 38a and 38b and converted by the IV conversion amplifier 39d is , Light receiving areas 38a, 3 basically
It can be regarded as the area of the imaging beam received on each of 8b. That is, the ratio of the voltage values is determined by the light receiving regions 38a and 38b.
It can be regarded as the area ratio of the imaging beams received respectively. This area ratio changes as the imaging beam moves due to changes in the distance of the object. That is, the area ratio can be regarded as the position equivalent value of the imaging beam. Thus, the area ratio, that is, the voltage value ratio can be used as the light beam imaging position information, that is, the distance information.

FIG. 9 shows an example of the relationship between the area ratio and the object distance. Further, here, the infrared distance sensor 30
a is a case where the optical axis is set to be substantially perpendicular to the floor surface 3 (see FIG. 2). In addition, the light receiving area 3
The image forming beam on 8a is defined as a region A, and the image forming beam on the light receiving region 38b is defined as a region B. The base line length is the distance between the optical axes of the irradiation lens 35a and the light receiving lens 37a, the beam light diameter is the diameter of the beam light emitted from the irradiation lens 35a, and the sensor installation height is from the light receiving lens 37a to the floor surface 3. The distance and the focal length are the focal length of the light receiving lens 37a, and the image distance is the distance from the light receiving lens 37a to the image plane of the two-divided PD 38. The two-division PD has a light receiving area of 4 mm × 4 mm × 2.

In the above description, the number of divisions of the multi-division PD 38 is two divisions, but it may be two or more divisions. Further, the multi-divided PD may be an undivided PD arranged side by side.

As shown in FIGS. 10 and 11, here, the description will be made assuming that the number of divisions of the multi-division PD 38 is four (hereinafter referred to as four-division PD38 '). As shown in FIG.
In this case, the 4-division PD 38 ′ is
It is divided into four light receiving regions 38d, 38e, 38f, and 38g (hereinafter, simply referred to as light receiving regions unless otherwise distinguished) and placed in parallel on the substrate 38c. In the 4-division PD 38 ′, the light beam reflected by the person 2 and imaged by the light-receiving lens 37 a is imaged on the 4-division PD 38 ′, so that a current is generated in each light-receiving region.

Then, as shown in FIG.
An IV conversion amplifier 39d is connected to each of d, 38e, 38f, and 38g. The current value of the current generated in each light receiving region is converted into a voltage value by the IV conversion amplifier 39d and input to the comparison circuit 39c. The comparison circuit 39c compares these to obtain
The light beam imaging position information, that is, distance information is calculated. In addition,
The comparison in the comparison circuit 39c is performed by the light receiving regions 38d, 38e,
The light beam imaging position information may be calculated by taking the ratio of the two light receiving regions having the larger output among 38f and 38g.

The number of divisions of the light receiving surface 38 is preferably 10 or less. Preferably 4 or less, most preferably 2
It is a division. By limiting the number of divisions, a simple structure can be achieved without increasing the number of auxiliary devices such as the IV conversion amplifier 39d.

Further, as shown in FIG. 10, when a multi-division PD 38 having a larger number of divisions than two divisions is used, when the imaged beam light largely moves and deviates from two light receiving regions, that is, measurement is performed. Even in the case where the distance of the target subject changes significantly, the light beam imaging position information can be calculated using the other two light receiving regions.

Further, a multi-division P having a larger number of divisions than two divisions
In the case of D38, the width of the imaging beam in the moving direction (horizontal direction in the drawing) due to the distance change of one light receiving region may be set to be smaller than the imaging beam diameter. this is,
This is to prevent a situation in which the voltage value ratio does not change even if the imaging beam moves because the imaging beam does not straddle at least two light receiving areas and enters one light receiving area. is there. That is, by doing so, it is possible to eliminate the situation where the voltage value ratio does not change even when the imaging beam moves, and it is possible to measure the distance stably and accurately. Further, a light receiving lens 37a having a telecentric optical system may be used. In this case, since the imaging beam diameter is constant even if the distance to the object changes, the voltage value ratio changes only by the movement of the imaging beam, so that the calculation can be simplified. A telecentric optical system is a telescope optical system in which the diaphragm is placed at one of the focal points of the objective lens. Further, even when the two-divided PD 38 is used, a telecentric optical system may be used as the light receiving lens 37a as described above. The case of using the two-division PD 38 will be described below.

Returning to FIG. 6, an infrared distance sensor 3 is further provided.
0a will be described. The light receiving lens 37a is provided with a coating that transmits only the light in the wavelength band of the irradiated light beam. Therefore, the position can be detected with little influence of ambient light. Further, in the above, the light beam is a thin parallel light beam, but may be a diffused light beam diffused to some extent. In the case of a diffused light flux, there may be diffusion to the extent that detection of the light beam imaging position information by the two-divided PD 38 does not interfere.

In the infrared distance sensor 30a, the wavelength of the light beam projected by the infrared light irradiation section 31a may be different for each sensor. In this case, the transmission wavelength band of the coating on the light receiving lens 37a is also set to the transmission wavelength band corresponding to the projected light beam. As a result, even when the adjacent light beams described with reference to FIG. 3B are overlapped with each other, there is no influence of the light beams from the adjacent sensors, and there is no need to perform control so that they do not irradiate at the same time. Can be simplified. Further, the infrared distance sensor 30a may be provided with a bandpass filter that causes the infrared LED 34a (light source) to blink at a constant frequency and causes the infrared light receiving section 32a to pass a signal of only that frequency. As a result, the influence of ambient light can be reduced. Further, by changing the modulation frequency for each sensor, even if the beam lights described in FIG. 3B overlap, the influence of the beam light of the adjacent sensor is eliminated. As a result, even if the light beams overlap, it is not necessary to control them so that they do not irradiate at the same time, and the monitoring system can be simplified. Further, it is also preferable to perform synchronous detection in which the polarity of the amplifier of the infrared light receiving section 32a is switched in synchronization with the irradiation timing of the infrared LED 34a.

The infrared distance sensor 30a uses infrared rays as the beam of light to be emitted, so that it cannot be seen by humans and does not cause discomfort. Also, the infrared distance sensor 30a
Is P of the infrared distance sensor 30b using a PSD described later.
The SD part may be simply replaced by the two-division PD 38.

In this way, the infrared distance sensor 30a is
Since the circuit configuration can be simplified by using the two-divided PD 38, the monitoring system can be inexpensive and simple. Further, especially by configuring the number of divisions into two, the circuit configuration can be greatly simplified, so that an inexpensive and simple monitoring system can be obtained.

Sensor controller 3 of infrared distance sensor 30a
3a performs modulation in order to distinguish it from ambient light when detecting the light beam imaging position information. The modulation is, for example, an operation in which light emission (irradiation) of the beam light is periodically repeated. In this case, the light emission of the light beam may be stopped, for example, by stopping the light emission of the light source or by rotating the light shielding plate or the slit.
Further, in addition to the above, the modulation may also change the output of the beam light depending on the intensity of the ambient light. Then, the sensor control unit 33a uses the output value of the two-division PD 38 when irradiating the beam light to determine when the beam light is irradiating 2
An output value is calculated by subtracting the output value of the divided PD 38.
Further, the sensor control unit 33a uses the sensor control unit 33a to ensure reliability.
Such an operation is performed a plurality of times, and the average output value is used as light beam imaging position information (hereinafter referred to as distance measurement signal). The sensor control unit 33a outputs the distance measurement signal value x, which is the value of the distance measurement signal, to the arithmetic device 120 as distance information.

As shown in the schematic view of FIG. 12, the distance value A to the target person 2 can be calculated by the following equation using trigonometry based on this distance measurement signal value x. A = f × w / (x−b) (1) f is the focal length of the lens when the light receiving lens 37a of the infrared light receiving section 32a is a single lens, and w is the infrared LE
The distance between D34a and the two-divided PD38, in other words, the distance (base line length) between the optical axes of the irradiation lens 35a and the light receiving lens 37a, and b indicates the bias value depending on the arrangement of the light receiving elements of the PD38. In addition, the focal length here is the focal length of a combination lens, which is generally used, when the combination lens is used. The control unit 121 of the arithmetic unit 120 calculates the distance A as described above.

In the above, the case where the infrared distance sensor 30a outputs the distance measurement signal value x as the distance information has been described, but the infrared distance sensor 30a is configured to output the distance value A itself calculated by the above method as the distance information. May be.

Next, referring to the block diagram of FIG. 13, PS
The infrared distance sensor 30b using D will be described.
The infrared distance sensor 30b includes an infrared light irradiation section 31b and an infrared light receiving section 32 as light irradiation means for irradiating the light beam.
b, a sensor control unit 33b that controls the entire infrared distance sensor 30b is included. Also, the sensor control unit 3
3b is inside the control unit 121 of the arithmetic unit 120 (see FIG. 4)
May be prepared for.

The infrared LED 34 is provided in the infrared light irradiation section 31b.
b and the irradiation lens 35b are provided, and the infrared LED
The infrared light emitted from 34b is applied to the person 2 as a thin parallel light beam light through the irradiation lens 35b.
The infrared light receiving section 32b is arranged near the light receiving lens 37b as an image forming optical system for forming an image of the beam light spot generated on the person 2 by the infrared light emitting section 31b, and in the vicinity of the image forming position by the light receiving lens 37b. And a one-dimensional PSD 36 as a light receiving means for receiving the light beam from the person 2. Further, the infrared distance sensor 30b has a PSD 36
It has a position information output unit 39b as a position information output device configured to output spot position information corresponding to the distance information to the person 2 based on the beam light spot position imaged on the top. . The position information output unit 39b
It is provided in the sensor control unit 33b.

The light receiving lens 37b is provided with a coating that transmits only the light in the irradiated wavelength band. Therefore, the position can be detected with little influence of ambient light. Further, in the above, the light beam is a thin parallel light beam, but may be a diffused light beam diffused to some extent. In the case of a diffused light beam, there may be a diffusion to the extent that complementing the position of the center of gravity by the PSD 36, which will be described later, does not interfere.

The PSD 36 will be further described with reference to FIG. FIG. 24 (a) is a schematic plan view,
FIG. 24 (b) is a schematic front sectional view. Figure 24
As shown in (a), the PSD 36 has a light receiving area larger than that of the imaging beam light, and the imaging beam light is moved in the moving direction (left and right direction in the figure) of the imaging beam light due to the distance change. It has such a length that the image forming beam light does not protrude due to the movement.

As shown in FIG. 24B, PSD3
Reference numeral 6 denotes the P layer 36a on the surface of the flat silicon that receives the imaging beam light, and the N layer 3 on the surface opposite to the P layer 36a.
6b, and I located between the P layer 36a and the N layer 36b.
It is composed of layer 36c. The image forming beam light imaged on the PSD 36 is converted into photoelectric and is converted into a photocurrent by the P layer 36.
The electrodes 36d attached to both ends of a are separately output.

The infrared distance sensor 30b outputs the barycentric position of the image forming beam light as spot position information by calculating the output signal of the photocurrent output from both ends of the PSD 36 by the position information output unit 39b. Thus, the distance to the person 2 can be measured. Also,
Since the emitted beam of light is infrared, it is invisible to humans and does not cause discomfort.

Sensor control section 3 of infrared distance sensor 30b
When the PSD 36 detects the position of the center of gravity of the imaging beam, the 3b performs modulation in order to distinguish it from ambient light. The modulation is the same operation as the modulation described for the infrared distance sensor 30a described above. In order to ensure reliability, the sensor control unit 33b performs the modulation operation a plurality of times and uses the average output value as the center-of-gravity supplementary signal (hereinafter referred to as the distance measurement signal) that is the spot position information. The sensor control unit 33 outputs the distance measurement signal value x, which is the value of the distance measurement signal, to the arithmetic device 120 as distance information. Further, the distance value A to the target person 2 can be calculated by using the trigonometry based on the distance measurement signal value x in the same manner as the method described in FIG. The calculation of the distance value A as described above is performed by the control unit 1 of the arithmetic device 120.
21.

Although the infrared distance sensor 30b has been described above as outputting the distance measurement signal value x as the distance information, it may be configured to output the distance value A itself as the distance information.

Thus, the infrared distance sensor 30b is
Since the PSD 36 can be simply configured by using the PSD 36, the monitoring device can be inexpensive and simple.

Although the distance measurement signal value x output from each infrared distance sensor 30 is modulated as described above, the influence of the ambient light is still left, and it fluctuates. In order to absorb this variation, the distance measurement signal values x acquired in time series are averaged to obtain data at that time. This data may be the average value of the distance value A calculated from the distance measurement signal value x, or the height H calculated from the distance value A described later.
The height H2 that is the average value of 1 or the depth L2 that is the average value of the depth L1 may be used. There are various ways of taking the average, but it is also possible to set a fixed time interval in advance and average the data between them, or to set the number to be averaged in advance and calculate the moving average value in time series. But it's okay. In the former case, the number of data is small, which is suitable for rough condition grasp. In the latter case, the number of data will be somewhat large, but detailed behavior can be followed.

As described above, the distance information of the person 2 can be obtained by using any of the distance sensors described above as the distance sensor 11 of the monitoring system 100. That is, the distance of the person 2 can be measured.

The operation of the monitoring system 100 of this embodiment will be described with reference to FIG. The monitoring system 100 monitors a monitoring zone 60 including a plurality of monitoring areas 6. The monitoring system 100 measures the distance of each corresponding monitoring area 6 by each distance sensor 11, and inputs the distance information as a value output from each distance sensor 11 to the control unit 121 of the arithmetic device 120 in time series. is doing. The control unit 121 causes the comparison calculation unit 122 to compare the input value with the reference distance information stored in the reference distance storage unit 125, and the monitoring unit 128 uses the comparison result to compare the input value with the person 2 existing in each monitoring area. Are watching.

Here, for example, when the person 2 enters the surveillance area 61 (see FIG. 3) of the surveillance zone 60, the distance of the person 2 who has entered is measured by the distance sensor 11 corresponding to the surveillance area 61, The distance information is the control unit 1
21 is output. Control unit 12 that has input the distance information
1, the comparison calculation unit 122 calculates the height and the position, which are the position information of the person 2. At this time, the comparison calculation unit 122
Calculates the depth of the person 2 from the floor surface 3 and the depth from the distance sensor 11 in the direction parallel to the floor surface 3 (X-axis direction in FIG. 1).

Referring now to the schematic side view of FIG.
An example of a method of calculating the height and position of the person 2 will be described.
Distance sensor 11 installed on the wall 4 from the floor 3 to the height H
However, it is assumed that the monitoring area 6 in the depth L (X-axis direction) from the wall 4 is being monitored. If the value of the distance of the person 2 existing in the monitoring area 6 from the distance sensor 11 is A, the height H1 and the depth L1 of the person 2 can be calculated by the following equations. H1 = AH / (H ² + L ² ) ^1/2 (2) L1 = AL / (H ² + L ² ) ^1/2 (3) The direction parallel to the floor 3 orthogonal to the depth L ( The position in the Y-axis direction (see FIG. 1) can be calculated from the calculated height H1, depth L1 and the distance measurement direction of the distance sensor 11 in the three-dimensional space. Further, the position can be roughly grasped from the set positions of the plurality of monitoring areas 6. Further, it can be roughly grasped by the distance sensor 11 that measures the distance of which monitoring area 6. In this way, the position information of the person 2 existing in the monitoring area 6 can be calculated. Further, for example, if the distance sensor 11 is arranged in a direction perpendicular to the floor surface 3, the position itself can be set as the position where the sensor is attached and the distance can be set as the height, so that the position information can be easily obtained.

In this way, the position information of each of the other monitoring areas 6 is also acquired simultaneously or sequentially. When the monitoring areas 6 corresponding to the plurality of distance sensors 11 overlap, the position information is acquired as described below.

Here, as shown in FIG. 3B, the control of the operation when the monitoring areas 6 corresponding to the plurality of distance sensors 11 overlap will be described. This control is performed by the timing controller 12 in the control unit 121 of the arithmetic device 120.
Do in 3. In this case, the distance of one distance sensor 11 is measured and then the distance of the next distance sensor 11 is measured. That is, the plurality of distance sensors 11 are controlled so as not to measure the distance at the same time. This kind of operation
This is repeated until the distances of all the provided distance sensors 11 are measured. This series of operations is one cycle. If the time T of one cycle is sufficiently short with respect to the movement of the person 2, it is easy to calculate the average moving speed and the moving distance of the person 2.

Further, as described above, the distance sensors 1
A plurality of distances are controlled by controlling not to measure the distances of the adjacent monitoring areas 6 at the same time (for example, every other monitoring area is measured at the same time) instead of measuring the distances according to 1. The sensor 11 can be made to measure the distance at the same time. By doing so, the time T of one cycle can be significantly shortened.

Further, the comparison calculation unit 122 determines that the person 2 calculated immediately before in the other monitoring area 6 which is the same or different.
If there is position information of, for example, position information of one cycle before,
Further, the moving distance and the average moving speed, which are the moving information of the person 2, are calculated by comparing with the position information. For example, the moving distance is based on the difference between the data of H1 and L1 before and after one cycle,
The average moving speed is a value obtained by dividing the difference between the data by the time T. Further, the position information and the movement information of the person 2 obtained by this are stored in the reference distance storage unit 125 in the storage unit 124 as reference distance information.

Next, the control unit 121 causes the monitoring unit 128 to determine the presence, posture, position and movement state of the person 2 based on the position information and the movement information as the comparison result calculated by the comparison calculation unit 122. This determination is also made from the position information and movement information calculated in other monitoring areas 6 (for example, when monitoring the monitoring area 61, the adjacent monitoring areas 62, 64, 65 (see FIG. 3)). To be done. For example, when the person 2 does not move and the height becomes low, it can be determined that the person 2 is sitting down, and the person 2 exists in a plurality of adjacent monitoring areas 6 at a low height and moves. If there is not, it can be determined that this person 2 is in a fallen state. In this way, the monitoring system 100
It is possible to monitor the entry, the presence and the presence state of the person 2 in the monitoring zone 60 including the plurality of monitoring areas 6.

In the above description, the number of the distance sensors 11 has been described. However, the number of the distance sensors 11 may be one, and in that case, the monitoring system 100 can be simplified and downsized. Further, the monitoring system 100 can perform high-speed processing because the distance information to be processed is reduced. In addition, the monitoring system 100
Since the distance sensor 11 using the divided PD is provided, the circuit configuration can be simplified, and the monitoring system 100 is inexpensive and simple.
Can be

As described above, in the surveillance system 100, the size of the person 2 entering the surveillance area 6 and the state of the person 2 (at which position, standing, sitting, falling down) It is possible to follow a series of movements such as whether the person 2 is moving, whether the person 2 is moving or when the person 2 exits with a simple device. In this case, since the difference from the reference distance is acquired, it can be used to judge the state even if the distance is not relatively accurate. Therefore, even if the light beam illuminating the person 2 which is one of the drawbacks of the infrared distance sensor 30 is lacked to some extent and an erroneous measurement is made, the person 2 is judged by a series of movements and a comprehensive judgment from a plurality of monitoring areas 6. The state can be determined.

In the closed space (toilet, bath, elevator, office), the monitoring zone 60 is surrounded by walls and the like, so that the distance to the floor 3 and the wall 4 when the person 2 is absent is set. The state of the person 2 can be determined by setting it as a reference distance and following the change from that state.

According to the first embodiment as described above,
The monitoring system 100 can judge the state of the person 2 and can very easily monitor whether the person 2 has fallen down or an illegal intruder exists. Moreover, since image processing using a camera that is psychologically uncomfortable is not used, it is very effective in monitoring the condition in a toilet, bath, etc., and high-speed processing is possible with a simple device. Further, in the monitoring system 100, when the infrared distance sensor 30a is used, the circuit configuration can be simplified, so that the monitoring system 100 can be a simple device and can be inexpensive and simple.

FIG. 15 is a schematic perspective view of the monitoring system 1 according to the second embodiment of the present invention. In the figure, the monitored object 2 exists on the floor surface 3 as the monitored area surface. Cartesian coordinate system XYZ so that the XY axes are placed on the floor 3.
Has been taken. A wall 4 is formed perpendicular to the floor surface 3, that is, on the YZ plane. The monitoring target 2 is a person in this embodiment.

On the other hand, a casing 10 including a plurality of distance sensors 11 for measuring the distance of the person 2 is installed on the wall 4 in the figure, and the casing 10 has a plurality of distances. The sensor 11 is installed corresponding to the monitoring area 6 as a plurality of monitoring target points. It is preferable that the monitoring areas 6 are arranged in two or more rows in a direction perpendicular to the main moving direction of the person 2. Moreover, the housing 10 is arranged in a direction perpendicular to the main moving direction of the person 2, that is, in the direction parallel to the floor surface 3, that is, in the direction parallel to the wall 4. Furthermore, the distance sensor 11 is
It is preferable to arrange two or more rows.

Further, as shown in FIG. 2, for example, when the monitoring system 1 is installed in a toilet, the housing 10 may be installed in the ceiling. Also, in the figure, the monitoring area 6 is 2
Although they are arranged in × 5, the number to be installed may be appropriately determined as described later.

The monitoring area 6 will be described with reference to the arrangement example of the monitoring area 6 in the schematic plan view of FIG. Figure 1
As shown in FIG. 6 (a), the plurality of monitoring areas include monitoring areas 61, 62,
63, 64, 65, 66 (hereinafter, simply referred to as the monitoring area 6 when the monitoring areas are not distinguished) are arranged in a grid pattern so as not to overlap each other. In each arrangement of the monitoring areas 6, the monitoring areas 6 in the rows far from the housing 10 are set as the monitoring areas 61, 62, 63, and the monitoring areas 6 in the rows near the housing 10 are set as the monitoring areas 64, 65, 66. To do. The number to be arranged is 2 columns or more, and in this embodiment, it is 3 rows and 2 columns (hereinafter referred to as 3 × 2), but it may be appropriately determined depending on conditions such as a place to be monitored and a person 2, for example, 2
It may be x2 or 3x3, 3x4. By arranging in this way, it is possible to easily determine whether the person 2 is approaching or moving away from the case 10 from the state described after each monitoring area 6. Further, the row-to-row distance P1 and the column-to-column distance P2 of the adjacent monitoring areas 6 are set to be narrower than the minimum width of the object, that is, the person 2.
By arranging the plurality of monitoring areas 6 in this way, the blind spot in the monitoring zone 60 can be substantially reduced, and therefore highly accurate monitoring can be performed.

Further, as shown in the arrangement example of the monitoring areas 6 in the schematic plan view of FIG. 16B, the adjacent monitoring areas 6 may overlap with each other. In this way, the monitoring zone 60
Since the blind spots inside can be reduced, it is effective for more accurate monitoring. In this case, the distance sensors 11 corresponding to the overlapping monitoring areas 6 need to be controlled so that they do not affect each other and do not irradiate at the same time. This control is performed by the timing controller 12 described above.
It may be performed in the same manner as the control by 3.

An example of the configuration of the monitoring system 1 will be described with reference to FIG. The monitoring system 1 is configured to include a housing 10 in which a plurality of distance sensors 11 are installed and an arithmetic device 20. The arithmetic unit 20 is typically a personal computer or a microcomputer. The plurality of distance sensors 11 are connected to the arithmetic device 20, and each of the distance sensors 11
It is configured to be able to obtain distance information from. Acquisition of distance information from the distance sensor 11 is preferably 10 m
every s to 500 ms, more preferably 50 ms to 20
It is configured so that it can be acquired every 0 ms. Further, the distance information is configured to be acquired from each distance sensor 11 in time series. The distance information is, for example, an output value from the distance sensor 11 before actually calculating the distance, but may be the distance itself to the target person 2. Further, although the distance sensor 11 and the arithmetic unit 20 are shown as separate bodies in the figure, they may be integrally configured.

Further, in the present embodiment, the distance sensor 11 is installed in the housing 10 in a size of 3 × 2 so as to correspond to the monitoring area 6 arranged in a size of 3 × 2 as described with reference to FIG. .

As the distance sensor 11 used, the infrared distance sensor 30 described in the first embodiment is used.

Although the distance measurement signal value x output from each infrared distance sensor 30 is modulated as described above, the influence of the ambient light remains slightly and is varied. In order to absorb this variation, the distance measurement signal values x acquired in time series are averaged to obtain data at that time. This data may be the average value of the distance value A calculated from the distance measurement signal value x, or the average value of the height H2 and the depth L1 which are the average values of the height H1 calculated from the distance value A described in FIG. Depth L2 which is also good. There are various ways of taking the average, but it is also possible to set a fixed time interval in advance and average the data between them, or to set the number to be averaged in advance and calculate the moving average value in time series. But it's okay. In the former case, the number of data is small, which is suitable for rough condition grasp. In the latter case, the number of data will be somewhat large, but detailed behavior can be followed.

The arithmetic unit 20 has a control unit 21 and controls the entire monitoring system 1. The plurality of distance sensors 11 are connected to and controlled by the control unit 21. A storage unit 24 is connected to the control unit 21 and can store data such as calculated information. Further storage unit 2
A distance information storage unit 25 that stores the distance measurement signal values x acquired by the distance sensor 11 in time series is provided in the unit 4.

Further, the control unit 21 is connected with an input device 26 for inputting information for operating the monitoring system 1 and an output device 27 for outputting a result processed by the monitoring system 1. The input device 26 is, for example, a touch panel, a keyboard or a mouse, and the output device 27 is, for example, a display, a printer or an alarm device. Although the input device 26 and the output device 27 are illustrated as being externally attached to the arithmetic device 20 in the present drawing, they may be incorporated therein.

Further, the control unit 21 is provided with a plurality of distance sensors 11 and a judgment unit 22 for judging the state of the person 2 based on the distance measurement signal value x stored in the distance information storage unit 25. There is. The configuration of the determination unit 22 will be described below.

The judgment unit 22 calculates the distance information difference between the distance measurement signal value x acquired by the distance sensor 11 and the immediately preceding distance measurement signal value x stored in the distance information storage unit 25. Then, the determination unit 22 compares the distance information difference with the first predetermined threshold value, determines that the person 2 has moved when the distance information difference is larger than the first predetermined threshold value, and determines the first difference. The person 2 is configured to determine that the person 2 is stationary when it is smaller than a predetermined threshold value. The first predetermined threshold will be described in detail later.

Further, the judgment unit 22 makes the above judgment for each of the plurality of distance sensors 11 over a certain period. 500 ms when the distance measurement interval of the distance sensor 11 is 100 ms (0.1 s) for a certain period.
It is preferably about (0.5 s). Further, the fixed period may be a period in which the distance measurement by the distance sensor 11 is performed about five times, or may be appropriately determined according to the system specifications, the monitoring situation, and the like.

Then, the judging section 22 finds the difference in the number of times that it is judged that there has been movement within a certain period and the number of times that it is judged to be still, and the difference in the number of times is larger than the second predetermined threshold value. It is configured to determine that there is a movement in the monitoring area 6 corresponding to the distance sensor 11. It is preferable that the second predetermined threshold value is set so that it is determined that there is a movement, for example, when the number of times that it is determined that there is at least movement is greater than the number of times that it is determined to be stationary. In such a case, the second predetermined threshold value is 1.

Further, the judging section 22 finds the difference between the number of the monitoring areas 6 judged to have moved and the number of the monitoring areas 6 judged to be stationary in the above-mentioned judgment, and based on this difference. It is configured to determine whether the person 2 is moving or is stationary as a whole. This decision is
For example, if there is at least one monitoring area that is determined to be in the operating state, it may be determined that the person 2 has moved as a whole. If the number of monitoring areas determined to have moved is three or more, it may be determined that the person 2 has moved as a whole.

Further, the determination unit 22 determines the floor surface 3 of the person 2 based on the relative position of each distance sensor 11 with respect to the floor surface 3 on which the person 2 exists and the relative distance measuring direction.
And the depth from the distance sensor 11 in the direction parallel to the floor surface 3 (X-axis direction in FIG. 15) are calculated. Further, the height and the depth are determined by the plurality of distance sensors 11
Is an average value of the distance information acquired from each of the above at fixed intervals. Alternatively, it may be a moving average value for a certain number of pieces of distance information.

Referring now to FIG. 18 and also to FIG.
The determination as to whether the person 2 is in a stationary state or in an operating state will be described with reference to FIG. 17 as appropriate. FIG. 18 shows this determination for each fixed period. This decision is
This is performed by the determination unit 22 in the control unit 21. Further, the distance measurement by the distance sensor 11, that is, the output of the distance measurement signal value x is
A case will be described where it is performed every 0.1 s (100 ms). In addition, here, the fixed period is 0.5 s (500 ms), that is, a period in which the distance sensor 11 measures the distance five times (the distance measurement signal value x is input five times). Further, the monitoring area 6 has the arrangement described above with reference to FIG.

The distance measurement signal value x input from the infrared distance sensor 30 fluctuates due to the inclusion of noise such as circuit noise and disturbance light noise. Such a variation in the distance measurement signal value x is caused by the distance value A of the person 2 measured by the distance sensor 11.
Since it is reflected as it is, it may cause a misjudgment. Therefore, the following method is used to determine whether the robot is in a stationary state or in a moving state.

First, the variation value of the distance measurement signal value x due to noise is measured in advance. Then, a value having a certain margin in the measured fluctuation value is set as the first predetermined threshold value. Next, the determination unit 22 compares the distance measurement signal value x input from the distance sensor 11 with the distance measurement signal value x stored in the distance information storage unit 25. Further, comparing with the distance measurement signal value x can reduce the influence of noise on the distance measurement signal value x, as compared with the distance value A calculated from the distance measurement signal value x by the above-described method. This is because. This is not a linear relationship between the distance measurement signal value x output from the distance sensor 11 and the calculated distance value A, and the distance value A is greatly influenced by noise as the distance measured increases. This is because the distance measurement error tends to increase.

By this comparison, the judgment unit 22 determines that the signal value difference between the distance measurement signal value x stored in the distance information storage unit 25 and the distance measurement signal value x input from the distance sensor 11 is less than the first predetermined threshold value. When it is large, it is determined that the monitoring area 6 corresponding to the distance sensor 11 has moved (operating state). The determination unit 22 also determines the distance measurement signal value x stored in the distance information storage unit 25 and the distance measurement signal value x input from the distance sensor 11.
When the signal value difference between and is smaller than the first predetermined threshold value, it is determined that there is no movement (stationary state) in the monitoring area 6 corresponding to this distance sensor 11. This determination is made for each monitoring area 6, that is, for each distance sensor 11. As a result, the determination unit 22 does not make an erroneous determination even for noise that is randomly mixed, for example.

Then, the judging section 22 makes such judgment for a certain period. The control unit 22 obtains the difference between the number of times it is determined that the user has moved during this fixed period and the number of times that the person is still.

When the difference in the number of times is larger than the second predetermined threshold value, the judgment unit 22 determines that the distance sensor 1 has the same value within the fixed period.
It is determined that the monitoring area 6 corresponding to 1 is in the operating state. Further, when the difference in the number of times is smaller than the second predetermined threshold value, the determination unit 22 determines that the monitoring area 6 corresponding to the distance sensor 11 is in the stationary state within this fixed period. This determination is made for each monitoring area 6. here,
The second predetermined threshold value is set so that it is determined that there has been a motion when the number of times the motion state is determined is greater than the number of times the stationary state is determined.

As a result, the judgment unit 22 does not make a wrong judgment even for shot-like or sudden noise due to, for example, the flicker of sunlight inserted through the window. This is the number of times it was judged to be the operating state and the number of times it was judged to be the stationary state over a certain period of time, even if it was judged that the operating state was momentary due to sudden noise even though it was actually in the stationary state. This is because it can be determined to be in a stationary state because it is compared with.

Further, the determination unit 22 determines that the person 2 is wholly determined from the difference in the number of monitoring areas between the number of monitoring areas determined to have moved and the number of monitoring areas determined to be stationary in the above determination. As to whether it is moving or stationary. Here, in this determination, if there is at least one monitoring area determined to be in the operating state, it is determined that the person 2 has moved as a whole.

As described above, the determination unit 22 determines whether the person 2 is in the stationary state or the operating state at regular intervals. Further, by determining whether the person 2 is in the stationary state or in the operating state by such a method, it is possible to reduce the influence of noise mixed in the distance measurement signal value x.

Further, a method of judging the posture state of the person 2 will be described. This judgment is made by the judgment unit 22 in the control unit 21.

First, the control unit 21 calculates the distance value A from the distance measurement signal value x acquired from the distance sensor 11 every 0.1 s by the method described in FIG. FIG. 19 shows an example of the calculated distance value A.

Next, the control section 21 calculates the height H1 and the depth L calculated by the method described with reference to FIG. 14 based on the distance value A.
Calculate 1. Further, the control unit 21 controls the height H1 and the depth L.
The average values H2 and L2 of 1 every 0.5 s are calculated. Figure 2
0 and the calculated average values H2 and L2 are shown in FIG. 21, respectively.

The control unit 21 converts the average value H2 of heights into some segment data. For example, -400 mm or less is classified as category 0, -400 to 200 mm is classified as category 1, 200 to 50.
0 mm is classified as category 2, 500 mm to 1000 mm is category 3, and 1000 mm or more is category 4.

FIG. 22 shows an example of a result obtained by converting the average value H2 of heights into segmented data. Here, the category 0 indicates a state in which the distance measurement is not normally performed due to, for example, a beam defect of the light beam received by the infrared distance sensor 30. That is, there is an object that cannot be identified as the person 2 in the monitoring area 6, but the height H1 cannot be identified. Category 1
Indicates a state within 200 mm from the reference height (for example, the floor), and usually a state in which no object or person 2 exists. Category 2 shows a state in which the person 2 is close to a fallen state.
Further, the category 3 indicates a state close to a state of leaning on something. Category 4 is a category indicating a state close to a standing state.

FIG. 23 shows an example of the result obtained by converting the depth average value L2 into segmented data. Similarly to the height H2, by converting the average value L2 of the depth into some segmented data, the person 2
It is possible to know the approximate depth from the distance sensor 11 at the position where is present. The depth division may be, for example, a proportionate distribution of the height division described above.

The determination unit 22 determines the state of the person 2 in consideration of the height and depth division data described above and the determination of whether the person 2 is in the stationary state or the moving state. For example, stationary as a whole and all height divisions 1
If so, there is nothing. That is, if it is a closed space, it indicates a vacant state. In addition, if the state of being stationary and having a height division state of 2 continues for a predetermined time or more, the person 2
Judge that is falling. Further, if it is in the state of category 4, it can be determined that it is standing.

Further, the judging unit 22 judges that the person 2 is in the housing 1 from the judgment result of whether the person 2 is moving or is stationary in each monitoring area 6 and the change of the height division.
With respect to 0, it is possible to judge whether the state is approaching or moving away.

If the person 2 is lying down or leaning on something for a certain period of time or more, the judging section 22 determines that the person 2 has an abnormality (for example, feels bad). to decide. Furthermore, if the person 2 is in that state and is still, the person 2 can be judged to be in a dangerous state (for example, the person 2 is unconscious), and the person can be judged to be in a detailed state. Thereby, for example, the administrator of the present system can know the abnormality of the monitoring zone as soon as possible, so that, for example, appropriate emergency treatment can be given to a suddenly ill person. Further, the determination unit 22 may issue a warning from a speaker provided in the monitoring zone, or may notify the outside, for example, a fire station, based on this determination.
At this time, the determination unit 22 can identify the falling position from the depth division data of each monitoring area 6, can further determine the detailed state, and can provide information.

In the above description, the number of the distance sensors 11 has been described, but the number of the distance sensors 11 may be one. In that case, the monitoring system 1 can be simplified and downsized. Further, the monitoring system 1 can perform high-speed processing because the distance information to be processed is reduced. Furthermore, since the monitoring system 1 includes the distance sensor 11 using the two-division PD, the circuit configuration can be simplified, and the monitoring system 1 can be inexpensive and simple.

As described above, in the surveillance system 1, the person 2 of what size enters the surveillance area 6 and the person 2
Follow a series of movements with a simple device such as what kind of state (at which position, standing, sitting, or falling) the person 2 is moving, and whether the person 2 has left. can do. In this case, since the state is determined from the movement of the person 2 and the division of height and depth, the state can be determined even if the distance is not so accurate. Therefore, even if the light beam illuminating the person 2 which is one of the drawbacks of the infrared distance sensor 30 is lacked to some extent and an erroneous measurement is made, the person 2 is judged by a series of movements and a comprehensive judgment from a plurality of monitoring areas 6. The state can be determined.

In the closed space (toilet, bath, elevator, office), the monitoring zone 60 is surrounded by walls and the like, so that the distance to the floor 3 and the wall 4 when the person 2 is absent is set. It is possible to determine the state of the person 2 by setting it as a reference distance, that is, as a background distance when the person 2 does not exist, and by following a change from that state.

According to the second embodiment as described above,
The monitoring system 1 can judge the state of the person 2 and can very easily monitor whether the person 2 has fallen down or an illegal intruder exists. Moreover, since image processing using a camera that is psychologically uncomfortable is not used, it is very effective in monitoring the state of a toilet or bath, and high-speed processing is possible with a simple device. Further, when the infrared distance sensor 30a is used, the monitoring system 1 can have a simple circuit configuration, and thus can be a simple device, and can have an inexpensive and simple configuration.

[0125]

As described above, according to the present invention, the distance sensor for measuring the distance to the object to be monitored, the distance information storage unit for storing the distance information acquired by the distance sensor, and the distance information storage unit. A determination unit that determines whether or not the monitoring target object moves based on the distance information stored in the monitoring target object, the distance sensor irradiating the monitoring target object with a light beam, and the monitoring target object. An image forming optical system for forming an image of the beam light reflected by the image forming device, and a light receiving surface which is arranged in the vicinity of an image forming position of the image forming optical system and receives the reflected beam light and is divided into a plurality of light receiving regions. Further, it receives signals from each of the light receiving areas, compares the intensities of the light beams incident on each of the light receiving areas with each other based on the received signals, and corresponds to the distance information to the monitored object. Beam light image forming position information Since it has a structure position information output device such that not only enables the monitoring of the correct target area, simple, and it is possible to provide a monitoring system capable of high-speed processing.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an outline of a monitoring system according to a first embodiment of the present invention.

FIG. 2 is a schematic perspective view showing an outline when the monitoring system according to the first embodiment of the present invention is installed in a toilet.

FIG. 3 is a schematic plan view illustrating an arrangement example (a) in which monitoring areas do not overlap and an arrangement example (b) in which monitoring areas overlap according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration example of a monitoring system used in the first embodiment of the present invention.

FIG. 5 is a schematic side view illustrating a case where the distance sensor according to the first embodiment of the present invention is installed with a curve.

FIG. 6 is a block diagram showing a configuration example of an infrared distance sensor using a two-division PD used in the embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a case of using two PDs in the case of FIG.

FIG. 8 is a conceptual diagram illustrating a case where two PDs are used in the case of FIG.

FIG. 9 is a diagram showing an example of a relationship between an area ratio and an object distance when an infrared distance sensor using a two-division PD used in the embodiment of the present invention is used.

FIG. 10 is a schematic diagram illustrating a 4-division PD used in the embodiment of the present invention.

FIG. 11 is a conceptual diagram illustrating a 4-division PD in the case of FIG.

FIG. 12 is a schematic diagram illustrating a method of calculating the distance to a monitoring target according to the embodiment of this invention.

FIG. 13 is a block diagram showing a configuration example of an infrared distance sensor using the PSD used in the embodiment of the present invention.

FIG. 14 is a schematic side view illustrating a method of calculating the height and depth of the monitoring target from the distance of the monitoring target in the embodiment of the present invention.

FIG. 15 is a schematic perspective view showing an outline of a monitoring system according to a second embodiment of the present invention.

FIG. 16 is a schematic plan view illustrating an arrangement example (a) of monitoring areas and an arrangement example (b) of overlapping monitoring areas according to the second embodiment of the present invention.

FIG. 17 is a block diagram showing a configuration example of a monitoring system used in the second embodiment of the present invention.

FIG. 18 is a diagram showing a determination result by a determination unit according to the second embodiment of the present invention.

FIG. 19 is a diagram showing a distance value calculated from distance information acquired by a distance sensor in the case of FIG. 18;

20 is a diagram showing an average value of heights calculated from distance information acquired by a distance sensor in the case of FIG. 19;

FIG. 21 is a diagram showing an average value of depth calculated from distance information acquired by a distance sensor in the case of FIG. 19;

22 is a diagram showing height divisions in the case of FIG. 20. FIG.

23 is a diagram showing depth division in the case of FIG. 21. FIG.

24 (a) is a schematic plan view and FIG. 24 (b) is a schematic front sectional view for explaining the PSD in the case of FIG.

[Explanation of symbols]

1,100 monitoring system 2 people 3 floor 4 walls 6 monitored areas 10 housing 11 Distance sensor 20, 120 arithmetic unit 21, 121 Control unit 22 Judgment section 24, 124 storage unit 25 Distance information storage 26,126 Input device 27,127 Output device 30 infrared distance sensor 30a Infrared distance sensor using 2-division PD Infrared distance sensor using 30b PSD 31a, 31b Infrared light irradiation unit 32a, 32b infrared light receiving section 33a, 33b Sensor control unit 36 PSD (position detection element) 37a, 37b Light receiving lens 38 2-split PD (photo detector) 60 monitoring zones 122 Comparison operation unit 123 Timing controller 125 Reference distance storage 128 monitoring section

Front Page Continuation (51) Int.Cl. ⁷ Identification code FI Theme Coat (reference) G08B 25/04 G01V 9/04 J (72) Inventor Yasuhiro Takemura 6-6, Rokubancho, Chiyoda-ku, Tokyo Sumitomo Osaka Cement Co., Ltd. In-house F-term (reference) 2F112 AA06 AA07 BA05 BA07 CA01 DA02 DA26 DA28 EA03 FA19 FA41 5C086 AA27 AA52 BA04 BA07 CA12 CA25 DA07 5C087 AA02 AA03 BB74 DD05 DD29 EE03 EE06 BB06 A07 BA03 A07 BA03 A05 AB03 A05A07 A05 A07 A07 A07 A07 BA05 BA37 BB01 CA32 CA80 DA01 DA07 EA05 EA07

Claims (6)

[Claims] 1. A distance sensor for measuring a distance to a monitoring target; a distance information storage unit for storing distance information obtained by the distance sensor; and a distance information storage unit for storing the distance information stored in the distance information storage unit. A distance irradiating means for irradiating the monitored object with a beam of light; and an image of the beam of light reflected by the monitored object. An image forming optical system; and a light receiving surface which is arranged in the vicinity of an image forming position by the image forming optical system and receives the reflected beam light and is divided into a plurality of light receiving areas; From the light receiving device, and based on the received signal, the intensities of the light beams incident on the respective light receiving regions are compared with each other, and the light beam imaging position information corresponding to the distance information to the monitored object is output. Location information configured as Has output device; monitoring system. 2. A distance sensor for measuring a distance to an object to be monitored; a distance information storage unit for storing distance information acquired by the distance sensor; and a distance information storage unit for storing the distance information stored in the distance information storage unit. A distance irradiating unit for irradiating the object to be monitored with light beam, and the light irradiating unit to generate light on the object to be monitored. It has an image forming optical system for forming an image of a light beam spot, and a light receiving unit arranged near the image forming position of the image forming optical system for receiving the beam light from the object to be monitored; A position information output device configured to output spot position information corresponding to distance information to the monitored object based on the imaged light beam spot position; a monitoring system. 3. The distance information storage unit is configured to store the distance information acquired by the distance sensor in time series;
The determination unit calculates a distance information difference between the distance information acquired by the distance sensor and the immediately preceding distance information stored in the time series, and compares the distance information difference with a first predetermined threshold value. When the distance information difference is larger than the first predetermined threshold value, it is determined that the monitoring target object has moved, and when the distance information difference is smaller than the first predetermined threshold value, the monitoring target object. Is configured to determine that it is stationary; The surveillance system of claim 1 or claim 2. 4. The number of times the determination unit compares the first predetermined threshold value with each of the plurality of distance sensors for a certain period of time, and determines that there is movement within the certain period of time. The method is configured to obtain a number of times difference from the number of times it is determined to be stationary, and determine that there is a movement at a monitoring target point of the sensor, the number difference being greater than a second predetermined threshold value. The monitoring system according to item 3. 5. The difference between the number of monitoring points determined by the determination unit and the number of monitoring points determined to be stationary, and the difference in the number of points. The monitoring system according to claim 4, wherein the monitoring target is configured to determine whether the monitored object is moving or stationary as a whole. 6. A distance sensor installed corresponding to a monitoring target point to be monitored, the distance sensor measuring a distance to the corresponding monitoring target point; distance information acquired by the distance sensor. A reference distance storage unit for storing reference distance information to be compared with; distance comparison means for comparing the distance information acquired from the distance sensor with the reference distance information; and based on a comparison result by the distance comparison means, A monitoring unit for monitoring a monitored object existing between the monitored point and the distance sensor; the distance sensor includes a light irradiation unit for irradiating the monitored object with a light beam, and the monitored object. An image forming optical system for forming an image of the reflected beam light, and a light receiving surface which is arranged in the vicinity of an image forming position of the image forming optical system and receives the reflected beam light and is divided into a plurality of light receiving regions. Existence Further, the beam corresponding to the distance information to the monitored object is obtained by receiving the signals from the respective light receiving regions, comparing the intensities of the light beams incident on the respective light receiving regions with each other based on the received signals. A position information output device configured to output optical imaging position information; a monitoring system.