JPH01232497A - Intruder sensor using fiber grating - Google Patents

Abstract

PURPOSE:To realize the easy and sure identification of intruders by using a fiber grating to divide the infrared laser light into some patterns and sensing the intruders from the moving states of spots of a spot projection picture produced by each of divided spot beams. CONSTITUTION:A fiber grating radiates the spot beams divided into some patterns with incidence of the laser light. An image pickup device 4 monitors the projection spots of the spot beams and stores the monitored spot projection pictures into a memory 5 for each fixed time. A data processing means 6 compares the stored spot projection picture with another projection picture that is stored in a memory 7 in case no detecting subject exists. Thus the moving spots are detected and the rough form of an intruder is decided from the number of moving spots, the moving extents of these spots, etc. Then the means 6 decides an intruder when the size of the intruder exceeds a prescribed level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a two-intrusion sound detector using an optical fiber and a laser.

[Conventional technology]

Conventionally, intruder detectors using optical fibers include, for example, an optical fiber placed on the floor, and this optical fiber is directly or indirectly deformed by the weight or movement of the intruder.
There is a device that detects an intruder by changing the frequency or phase of light that passes through an optical fiber.

[Problems to be Solved by the Invention] However, in the conventional device described above, there is a problem in that the optical fiber is slightly deformed due to causes other than the intruder, and it is difficult to distinguish between cases where there is an intruder and cases where there is no intruder. Nine.

This invention was made to solve the above-mentioned problems, and it is possible to easily distinguish between intruders and other cases, and to accurately detect intruders. The purpose of this study is to obtain an intruder detector using teiging.

[Means for solving problems]

An intruder detector using a fiber grating according to the present invention includes a fiber grating that receives a laser beam and emits a spot beam, an image pickup device that monitors a projected spot of this spot beam, and a monitored spot projected image. A moving spot is detected by comparing the frame memory stored at regular intervals with the spot projected image stored in the frame memory and the spot projected image when there is no object to be detected, and from the moving status of this spot, an approximate estimate of the intruding object is detected. It is equipped with data processing means that recognizes the shape of.

[Effect]

The fiber grating according to the present invention emits a spot beam divided into patterns on which laser light is incident. The projected spot of this spot beam is monitored by an imaging device, and the monitored spot projected image is stored in a memory at regular intervals. The data processing means detects moving spots by comparing the stored spot projection image with a spot projection image stored in advance in another memory in the case where there is no object to be detected, and detects the number of moving spots and the amount of movement wJ. Detect the approximate shape of the intruding object from etc. Further, the data processing means determines that the intruding object is an intruder when the size of the intruding object exceeds a predetermined size.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of the intruder detector according to this embodiment, where 1 is a laser drive section, and 2 is a laser diode driven by the laser drive section 1 to emit an infrared laser beam. 3 is a fiber grating, which is a small diameter optical fiber 3a as shown in FIG.

3b are arranged in parallel to form fiber grades 3c,
3d is formed, and this fiber grating 3C23d is placed in close contact with the fibers 3a and 3b so that their directions are directly aligned. The fiber grating receives an infrared laser beam 8, which is divided into several turns from the opposite side by its diffraction effect, and emits nine spot beams 9. 4 is an imaging device (for example, a COD camera) that monitors the projection of the spot beam 9 onto the floor etc. 10; 5 is a frame memory that stores the monitored spot projection image (substrate array) at regular intervals; 7 is a A reference data memory 6 stores each spot position data of a spot projection image in a state where there is no object to be detected, and 6 compares the spot projection images stored in the frame memory 5 and the reference data memory 7 and performs data processing. It is determined by the data processing unit that performs the processing.

Next, the operation of the above configuration will be explained. laser diode 2
is driven by a laser drive unit l and emits an infrared laser beam. The fiber grating 3 receives this infrared laser beam 8, and emits from the opposite side a spot beam 9 that is regularly divided by diffraction. The spot beam 9 is projected onto the floor or the like to form a projection spot 10, and the image pickup device 4 monitors this projection spora) 10 and stores the spot projection image in the frame memory 5 at regular intervals.

FIG. 3(a) shows an example of a spot projection image when there is no object to be detected, and this image is stored in the reference data memory. FIG. 3(b) shows an example of a spot projection image when some spots are moved by an invading object,
FIG. 3(c) shows a spot projection image in which only moving spots are extracted by comparing FIG. 3(a) and FIG. 3(b).

Here, assuming that the latest spot projection image stored in the frame memory 5 is the image 1 shown in FIG. 3(b), the data processing unit 6 outputs the image shown in FIG.

The spot position data in the image of (b) is compared, and the image of only the moving spot shown in FIG. 3(c) is extracted.

By performing a certain calculation on this moving spot, the approximate two-dimensional shape of the intruding object is detected as shown in FIG. 5(a).

FIG. 4 is an explanatory diagram regarding the calculation of the amount of movement of the moving spot, in which 11 is the floor surface, 12 is the image plane of the imaging device 4, and 1
3 is an invading object. Assume XYZ orthogonal coordinates on the floor surface 11, and assume UVZ orthogonal coordinates on the image plane 12.

Also, the center of the fi/g grating 3 is located at a distance d from the center νU of the image plane 12 in the V coordinate direction, and the center of the grating 3 is located 7 eyes/(the grating 3
Let the height from the fiber grating 3 to the image plane 12 be l. The n-th projection spot formed on the floor surface 11 by the spot beam 9 of the fiber grating 3 is 5(n)=(Xn
, Yn, Zn), and the spot formed on the image plane 12 corresponding to s(n) as 5(
n) = (Un, Vn, Zn), the spot where spot 5(n) hit the intruding object 13 and moved is s
' (n) = (X'n, Y'n, Z'n)
, ri' (the spot formed on the timing crane 12 corresponding to the season is 8'(n) = (U'n).

V'n, Z'n). 5(n) to s'(n
) is the amount of movement of the spot from 5(n) to S' (the amount of movement to season and d, h.

It can be calculated by l. The amount of movement of the other moving spots is calculated in the same way, and a certain calculation is performed on all the moving spots based on this amount of movement to obtain the approximate three-dimensional shape of the intruding object (for example, Fig. 5 (b)
), the shape shown in (e)) is detected. When the approximate two-dimensional or three-dimensional shape detected in this way exceeds a predetermined size, the data processing unit 6 determines that the intruding object is an intruder, and reports the intruder to an external device (not shown). Outputs signal S.

Furthermore, by repeating each of the above calculation processes on the latest images of the detection range that are taken in at regular intervals (for example, video signal transmission cycles), the action locus of the intruding object is detected as shown in FIG. 5(d). be able to. in this way,
In this embodiment, the approximate shape and movement status of an intruding object can be detected in real time, and this information can also be output to an external device together with an intruder alarm.

〔Effect of the invention〕

As described above, according to the present invention, an infrared laser beam is divided into nine turns by a fiber grating, and an intruder is detected from the movement status of the spot in the spot projection image of each divided spot beam. By coarsely decomposing the space using spot projection images, the approximate shape of the intruding object can be detected, although the shape recognition of the decomposition layer is low, and the intruder can be easily and reliably identified. Further, since no complicated image processing is required, the processing time can be shortened, and the approximate shape and movement trajectory of the intruder can be detected in real time. Furthermore, when transmitting information about an intruder to a remote location, it is only necessary to send the components of the intruder's shape (major axis length, short axis length, height, etc.) and coordinates within the detection range. information can be sent to external devices in real time, and the behavior of intruders can be instantly grasped even in remote locations.

[Brief explanation of the drawing]

FIG. 1 is a diagram of the intruder detector according to the present invention, FIG. 2 is a schematic perspective view of the fiber grating according to the present invention, and FIGS. , a diagram showing an example of a switch projection image when an intruding object is present and when only a moving spot is extracted, FIG. 4 is a ninth explanatory diagram of spot movement amount calculation in this invention, and FIGS. 5(a) to ( d) is a diagram showing the approximate shape and movement locus of an intruding object detected from the movement status of the spot in the present invention. ■... Laser drive unit, 2... Laser diode, 3
...Fiber grating, 4...Imaging device, 5.
... Frame memory, 6... Data processing section, 7...
Reference data memory, 8...Laser light, 9...Spot beam, 10...Projection, 11 points. Figure 1 1: Laser drive unit 4: Imager 5: Frame memory 6: Data processing unit 7: Reference data memory Figure 2 Figure 3 ((7) (b) (C) Figure 4 Figure 5

Claims (1)

[Claims] A laser that emits an infrared laser beam, a fiber grating that receives the laser beam and outputs a spot beam divided into a certain pattern, an imager that monitors a projected spot of the spot beam, and a fiber grating that emits a spot beam that is divided into a certain pattern. A frame memory that stores spot projection images at regular time intervals, a reference data memory that stores spot position data of each spot projection image in a state where there is no object to be detected, and a frame memory that stores spot projection images at regular time intervals. A moving spot is detected by comparing each spot position data of the spot projection image and each spot position data stored in the reference data memory, and the approximate shape of the intruding object is recognized from the movement status of this spot. An intruder detector using a fiber grating, characterized in that it is equipped with a data processing means that determines an object to be an intruder if its shape exceeds a predetermined size.