JP2023174046A - Object detection device, security system, object detection method, and program - Google Patents

Abstract

To make it possible to detect an object in a non-detection area that is originally outside a detection range of a ranging sensor.SOLUTION: An object detection device includes: a ranging unit configured to measure a return time of reflected light of a laser beam from an object in a detection area that can be irradiated with the laser beam to obtain a distance to the object; and an object detection unit configured to three-dimensionally grasp a shape of the object based on the distance obtained by the ranging unit. When a non-detection portion is generated in which the distance to the object cannot be obtained by the ranging unit, the object detection unit estimates that the object is present in a non-detection area in which the ranging unit cannot detect the object in principle in the non-detection portion.SELECTED DRAWING: Figure 7

Description

The present invention relates to an object detection device, a security system, an object detection method, and a program.

2. Description of the Related Art Conventionally, object detection devices have been disclosed that detect intrusion of an object such as a person into a detection area. In such an object detection device, distance measurement such as 3D-LiDAR is used to detect the intrusion of an object such as a person into the detection area based on a distance image obtained from the reflected light of the laser beam irradiated to the detection area. Some use sensors.

Japanese Patent Application Publication No. 2006-46961

However, in the case of a distance measurement sensor such as 3D-LiDAR, which measures the distance to an object by emitting laser light within a predetermined detection area and measuring the return time of the reflected light, Since reflected light cannot be received from objects in the immediate vicinity of the distance sensor, this becomes a non-detection area where objects cannot be detected in principle.

The present invention has been made in view of the above, and an object of the present invention is to enable object detection in a non-detection area that is originally outside the detection range of a distance measurement sensor.

In order to solve the above-mentioned problems and achieve the object, the present invention measures the return time of the reflected light of the laser beam from an object in a detection area that can be irradiated with the laser beam, and obtains the distance to the object. The object detection section includes a distance measurement section and an object detection section that grasps the shape of the object in three dimensions based on the distance obtained by the distance measurement section. If there is a non-detection area where it is not possible to obtain the distance, the object exists in a non-detection area where the ranging section cannot, in principle, detect the object among the non-detection areas. It is characterized by making a guess.

According to the present invention, by estimating the presence of an object in a non-detection area where an object cannot be detected in principle, which is located between a rangefinder and a detection area by the rangefinder, This has the effect of making it possible to detect an object in a non-detection area that is outside the detection range of the camera.

FIG. 1 is a diagram illustrating a schematic configuration of a security system using an object detection device according to the present invention. FIG. 2 is a perspective view showing an example of an object detection device. FIG. 3 is a diagram showing an example of installation of the object detection device. FIG. 4 is a block diagram showing an example of the configuration of the object detection device. FIG. 5 is a diagram showing an example in which an undetected portion occurs behind a moving object. FIG. 6 is a diagram showing another example in which an undetected portion occurs behind a moving object. FIG. 7 is a flowchart showing the flow of processing in the object detection section of the object detection device.

Embodiments of an object detection device, a security system, an object detection method, and a program will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment.

FIG. 1 is a diagram illustrating a schematic configuration of a security system 1 using an object detection device 10 according to the present invention. As shown in FIG. 1, the security system 1 includes an object detection device 10 installed at a security target 20, a security device 40, and a monitoring center 30 located remote from the security target 20.

The object detection device 10 and the security device 40 that constitute the security system are connected via a network 50 such as a LAN (Local Area Network), and are capable of communicating with each other. Note that the communication method between the object detection device 10 and the security device 40 may be a wireless communication method or a wired communication method.

The security device 40 is also connected to a fire sensor and a human body detection sensor (not shown) via a network, and is capable of receiving a fire signal from the fire sensor, a detection signal from the human body detection sensor, and the like. Further, the security device 40 is capable of communicating with a monitoring center 30 located at a remote location relative to the security target 20 via an external network 60, which is the Internet, for example. Here, it is assumed that the security target 20 is a building such as a store, an office, a tenant building, an apartment, or a residence.

The security device 40 has at least a “security mode” and a “security release mode” as operation modes, and notifies the object detection device 10 of the operation mode set according to an operation by an administrator or the like of the security target 20. Note that the operation mode will be described later.

The object detection device 10 transmits detection information of objects in the security target 20 to the security device 40 via the network 50. Note that the object detection device 10 may not transmit detection information of an object in the security target 20 depending on the operation mode of the security device 40.

Upon receiving the object detection information from the object detection device 10, the security device 40 transmits the abnormality of the security target 20, including the received object detection information, to the monitoring center 30 via the external network 60, depending on the operation mode. report. Further, upon receiving a fire signal from a fire sensor, a detection signal from a human body detection sensor, etc., the security device 40 reports the received signal as an abnormality to the monitoring center 30, depending on the operation mode.

Next, the operation mode of the security device 40 will be briefly explained.

"Security mode" is an operation mode for guarding an unattended security target 20. When the security device 40 set to the "security mode" receives object detection information from the object detection device 10, a fire signal from the fire sensor, a detection signal from the human body detection sensor, etc. The received signal is reported to the monitoring center 30 as an abnormality. In addition, the security device 40 may perform an operation to report an abnormality and also perform an operation to leave a history of the operation, or may notify the security target 20 of an abnormality with an alarm sound, light, or the like.

The "security release mode" is an operation mode when there is a person concerned inside the security target 20 and security is not required. Even if the security device 40 set to the "security release mode" receives object detection information from the object detection device 10, detection signal from the human body detection sensor, etc., it does not determine that there is an abnormality in the security target 20. No action is taken to report the abnormality to the monitoring center 30. This is because even if the presence of an object is detected by the object detection device 10 or the like, it is determined that a related person has been detected.

In the monitoring center 30, when an abnormality is reported from the security device 40, the contents of the report etc. are displayed on the monitor. For example, a supervisor monitors the security target 20 to see if an abnormality has occurred based on the displays on these monitors. When the guard recognizes that an abnormality has occurred within the security target 20, he/she instructs the guard on standby to head towards the security target 20, or reports it to related organizations such as the police or fire department as necessary. I'll go there. Furthermore, the monitoring center 30 records the details of the abnormality reported from the security device 40 in a recording device. Furthermore, the monitoring center 30 may be configured to transmit abnormality notifications to mobile terminals (mobile phones, etc.) of users (contractors, etc.) of the security system 1.

Next, the configuration of the object detection device 10 will be explained.

FIG. 2 is a perspective view showing an example of the object detection device 10, and FIG. 3 is a diagram showing an example of installation of the object detection device 10. As shown in FIG. 3, the object detection device 10 is installed on the ceiling 90 of the security target 20. Note that the object detection device 10 shown in FIG. 2 shows an installation posture when it is installed on a ceiling 90.

The object detection device 10 includes a distance measurement unit 12, which is, for example, a 3D-LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), which is a three-dimensional distance measurement sensor capable of measuring distance. 3D-LiDAR measures the scattered light of pulsed laser irradiation and analyzes the distance to a distant object. Specifically, the distance measuring unit 12 irradiates a laser beam, measures the return time of the reflected laser beam from an object, and measures the distance and direction to the object. In the distance measuring unit 12, each measurement result of the laser beam irradiated all over the area is expressed as a "point", and by collecting the "dots", the distance to the object can be determined in real time in a "stippling" style. It becomes possible to grasp the position, shape, etc.

As shown in FIG. 2, an object detection device 10 including a distance measuring unit 12 that is a 3D-LiDAR radially irradiates a security target 20 with laser light at regular intervals inside a protective cover 11 that is a transparent member. It includes a light emitting section 12a and a light receiving section 12b that detects reflected light, which is a laser beam reflected by an object within the detection area A1.

Laser light scanned from the light emitting unit 12a reaches the area around the object detection device 10 at regular intervals, and when the laser light is reflected by a moving object O at the position where it has reached, the reflected light is transmitted to the light receiving unit. 12b and is detected, and as shown in FIG. 3, a detection area A1 is formed, which is an area in which the distance measuring section 12 can detect the moving object O.

As shown in FIG. 3, the object detection device 10 is a crime prevention sensor that is installed on a ceiling 90 and monitors the security target 20 from above.

The object detection device 10 is capable of measuring a distance from an object 2 m away, for example (the distance varies depending on the model), and cannot receive reflections from the object unless it is a certain distance away. This is because the switching from irradiation of laser light by the light emitting section 12a to reception of reflected light by the light receiving section 12b is not done in time. That is, as shown in FIG. 3, the object detection device 10 sets the immediate area as a non-detection area A0 where an object cannot be detected in principle.

FIG. 4 is a block diagram showing an example of the configuration of the object detection device 10. As shown in FIG. 4, the object detection device 10 includes a distance measuring section 12, a control section 13, a storage section 14, and a notification section 15.

The distance measuring section 12 includes a light emitting section 12a that emits laser light radially at regular intervals, and a light receiving section 12b that detects reflected light that is laser light reflected by an object within the detection area A1.

The control unit 13 has a computer configuration including, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) for storing programs, and a RAM (Random Access Memory) used as a work area. The control unit 13 causes the CPU to execute a program stored in the ROM to perform control operations and arithmetic processing for the detection process of the moving object O by the object detection device 10 according to the operation mode of the security device 40, etc. The object detection unit 131 functions as an object detection unit 131 for detecting objects.

Note that the program executed by the control unit 13 of the object detection device 10 of the present embodiment is provided as being pre-installed in a ROM or the like.

The program executed by the control unit 13 of the object detection device 10 of this embodiment is a file in an installable format or an executable format, and is stored on a CD-ROM, flexible disk (FD), CD-R, or DVD (Digital Versatile). It may also be configured to be recorded on a computer-readable recording medium such as a disc) and provided.

Furthermore, the program executed by the control unit 13 of the object detection device 10 of the present embodiment is configured to be stored on a computer connected to a network such as the Internet, and provided by being downloaded via the network. Also good. Furthermore, the program executed by the control unit 13 of the object detection device 10 of this embodiment may be configured to be provided or distributed via a network such as the Internet.

The object detection unit 131 of the control unit 13 grasps the shape of the object in three dimensions in the detection area A1 based on the distance to the object obtained from the distance measurement unit 12, and determines the presence or absence of a moving object O such as an intruder. to decide. More specifically, the object detection unit 131 recognizes, as one moving object O, a collection of data (such as a point group) that has similar distances and reflectances and moves as a unit. Then, the object detection unit 131 outputs detection information to the security device 40 when determining that an object is present.

In addition, the object detection unit 131 is located between the distance measurement unit 12 and the detection area A1 when the non-detection portion X (see FIGS. 5 and 6) is generated by the distance measurement unit 12. It is assumed that the moving object O exists in the non-detection area A0 where no object can be detected. This is because when there is an object in the non-detection area A0, a non-detection portion X is generated behind the object (a portion that is shadowed by the laser beam by the object).

Here, FIG. 5 is a diagram showing an example in which an undetected portion X is generated behind the moving object O. FIG. 5 shows a case where the head of the moving object O, which is an intruder, is in the non-detection area A0. In this case, although the distance to the head of the moving object O cannot be obtained, an undetected portion X is generated behind the head of the moving object O. As shown in FIG. 5, when the non-detection part X generated behind the head of the moving object O is in contact with the boundary between the detection area A1 and the outside of the detection area A1, the object detection unit 131 detects the non-detection part X in the non-detection area A0. It infers that the moving object O exists, determines the moving object O to be an intruder, and outputs detection information.

On the other hand, FIG. 6 is a diagram showing another example in which an undetected portion X occurs behind the moving object O. FIG. 6 shows a case where a moving object O, which is a flying object such as an insect (for example, a moth), has entered the non-detection area A0. In this case, although the distance to the moving object O cannot be obtained, an undetected portion X is generated behind the moving object O. As shown in FIG. 6, the object detection unit 131 estimates that the moving object O exists when the undetected portion X that occurs behind the moving object O is far from the boundary between the detection area A1 and the outside of the detection area A1. At the same time, the moving object O is determined to be a flying object such as an insect (for example, a moth), and no detection information is output.

The object detection unit 131 detects the occurrence of the non-detection portion X, determines that the moving object O is an intruder because the non-detection portion It continuously monitors whether the detection area Even if the non-detection portion X and the detection area A1 come into contact again, it may continue to be determined that it is caused by a flying object such as an insect. In this case, when it is determined that there is an intruder, detection information is output to the alarm device 40, and when it is determined that the intruder is a flying object such as an insect, the previously output detection information is canceled.

The storage unit 14 is a storage unit in which information can be rewritten, such as a Flash ROM. The storage unit 14 stores various information used in the detection process of the moving object O.

The notification section 15 includes a speaker 15a that emits a notification sound based on the output of the control section 13, and a display section 15b such as an LED that emits light based on the output of the control section 13.

The operation of the object detection device 10 will be described below. FIG. 7 is a flowchart showing the flow of processing in the object detection unit 131 of the object detection device 10.

The object detection unit 131 determines whether an undetected portion X (see FIGS. 5 and 6) occurs in the detection area A1 (step S1).

If the distance measuring unit 12 determines that the non-detection portion X (see FIGS. 5 and 6) has occurred in the detection area A1 (Yes in step S1), the object detection unit 131 It is estimated that a moving object O exists (step S2).

Note that if the distance measuring unit 12 detects that no undetected portion X (see FIGS. 5 and 6) has occurred in the detection area A1, the object detection unit 131 ends without outputting the detection information (step S1 No).

Next, if the undetected portion X generated behind the moving object O is in contact with the boundary of the detection area A1 (Yes in step S3), the object detection unit 131 determines the moving object O to be an intruder (step S4). ), and outputs the detection information to the security device 40 (step S5).

Further, if the non-detection portion X generated behind the moving object O is away from the boundary of the detection area A1 (No in step S3), the object detection unit 131 detects the moving object O as an insect (for example, a moth) or the like. It is determined that it is a flying object (step S6), and the process ends without outputting the detection information.

As described above, according to the present embodiment, by estimating the presence of an object in the non-detection area where an object cannot be detected in principle, which is located between the distance measurement section and the detection area by the distance measurement section, This has the effect of making it possible to detect an object in a non-detection area that is originally outside the detection range of the distance measuring section.

Additionally, if the moving object O is determined to be a flying object such as an insect (for example, a moth), false alarms can be prevented by not outputting detection information or canceling previously output detection information. .

Note that at the same time as the object detection device 10 performs the process shown in the flowchart of FIG. 7, it also performs a process of detecting the moving object O and determining whether the moving object O is an intruder.

Furthermore, the security device 40 may not immediately report the detection information received from the object detection device 10 to the monitoring center 30, but may report the detection information after a predetermined period of time. With this configuration, if information indicating that the detection information is a false alarm is received from the object detection device 10 within a predetermined period of time, it is possible to prevent false alarms from being sent to the monitoring center.

Further, among the functions of the embodiment described above, the object detection section 131 may be configured to receive distance information to the object from the distance measurement section 12 of the object detection device 10 in preparation for a security device.

Moreover, each function (object detection unit 131) of the embodiment described above can be realized by one or more processing circuits. Here, the term "processing circuit" as used herein refers to a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, or a processor designed to execute each function explained above. It includes devices such as ASIC (Application Specific Integrated Circuit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), and conventional circuit modules.

1 Security system 10 Object detection device 12 Ranging section 40 Security device 131 Object detection section A1 Detection area A0 Non-detection area X Non-detection part

Claims (9)

a distance measuring unit that measures the return time of the reflected light of the laser beam from an object in a detection area that can be irradiated with the laser beam, and obtains the distance to the object;
an object detection unit that grasps the shape of the object in three dimensions based on the distance obtained by the distance measurement unit;
Equipped with
If a non-detection portion occurs in which the distance to the object cannot be determined by the distance measurement portion, the object detection portion may in principle detect the object from among the non-detection portions. Presuming that the object exists in a non-detection area where it cannot be detected;
An object detection device characterized by: The object detection unit determines that the object is an intruder when the non-detection portion reaches a boundary of the detection area.
The object detection device according to claim 1, characterized in that: The object detection unit determines that the object is a flying object when the non-detection portion is away from a boundary of the detection area.
The object detection device according to claim 1, characterized in that: The object detection unit determines that the object is a flying object when the non-detection portion moves away from the boundary of the detection area even temporarily.
The object detection device according to claim 2, characterized in that: When the object detection unit determines that the object is a flying object, the object detection unit determines that the object is an intruder as a false alarm.
The object detection device according to claim 4, characterized in that: The distance measuring unit is 3D-LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging),
The object detection device according to any one of claims 1 to 5, characterized in that: a distance measuring unit that measures the return time of the reflected light of the laser beam from an object in a detection area that can be irradiated with the laser beam, and obtains the distance to the object;
a security device that grasps the shape of the object in three dimensions based on the distance obtained by the distance measuring unit;
A security system equipped with
In the security device, when a non-detection portion occurs in which the distance to the object cannot be obtained by the distance measurement section, the distance measurement section in principle detects the object in the non-detection portion. infer that the object exists in a non-detection area where it is not possible to
A security system characterized by The return time of the reflected laser beam from an object in the detection area where the laser beam can be irradiated is measured, and the shape of the object is three-dimensionally determined based on the distance obtained from the distance measuring section that obtains the distance to the object. A method for detecting an object in a system that initially grasps the object,
If there is a non-detection part where the distance to the object cannot be obtained by the distance measurement section, there is a non-detection part where the distance measurement part cannot theoretically detect the object. inferring that the object exists in the detection area;
An object detection method characterized by: computer,
The return time of the reflected laser beam from an object in the detection area where the laser beam can be irradiated is measured, and the shape of the object is three-dimensionally determined based on the distance obtained from the distance measuring section that obtains the distance to the object. It functions as an object detection unit that grasps the object originally,
If a non-detection portion occurs in which the distance to the object cannot be determined by the distance measurement portion, the object detection portion may in principle detect the object from among the non-detection portions. Presuming that the object exists in a non-detection area where it cannot be detected;
program.

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