JPH0581575A - Ranging type invader detector - Google Patents

Abstract

PURPOSE:To relax a restriction condition concerning a installation location than that of a type which uses only the light receiving quantity of reflected light. CONSTITUTION:A flood-lighting means 1 projects a light beam to a detecting area. The reflecting light of the light beam formed by an invader into the detecting area forms a light collective spot on the light receiving surface of a position sensor 22 consisting of PSD through an optical system for receiving light 21. The light collective spot moves on the light-receiving surface of the position sensor 22 in accordance with a distance to the invader 9. Besides, position signals I1 and I2 being current signals are outputted from the position sensor 22 in accordance with the position of the light collective spot. A distance calculation means 4 determines the distance to the invader 9 based on the position signals I1 and I2. An information judging means 4 outputs an information signal when the distance to the invader 9 is within a prescribed range scale.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention detects an intruder in a detection area based on the distance to the intruder.
The present invention relates to a distance-measuring intruder detector used for informing a visitor or controlling an automatic door.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, infrared rays are projected onto a detection area by a light projecting means 1 and reflected light from an object is received by a light receiving means 2 to obtain information contained in the reflected light. An active object detector for detecting an intruder 9 in the detection area based on the above is provided.

For example, as an object detector for detecting an intruding object on the basis of the received light amount of the reflected light, one which determines that the intruding object exists in the detection area when the reflected light amount exceeds a predetermined threshold, and There is provided a device that focuses on the change and determines that an object has entered the detection area when the change amount exceeds a predetermined threshold value.

[0004]

By the way, in the former configuration for detecting the presence or absence of an intruding object in the detection area based on the magnitude of the received light amount of the reflected light, as shown in FIG. If the object U is present in the area D, the object U will be detected even if it is not an intruding object. Therefore, it is necessary to satisfy the constraint condition that the object U is installed so that no other object exists in the detection area D. That is, since the installation conditions are restricted, there is a problem that it cannot be used in a place where there are many articles such as figurines, luggage, and plants such as a storefront of a store.

In the latter configuration in which the presence or absence of an intruding object in the detection area is detected based on the change amount of the received light amount of the reflected light, the change amount of the received light amount is detected. 11), there is no change in the amount of received light, so that the rate of change in the amount of received light becomes large and the intruding object can be detected as shown in FIG. 11B only when the intruding object moves. Can be avoided.

However, since the presence or absence of an intruding object is detected based on the amount of reflected light, there is a problem that it is affected by the reflectance of the intruding object and the reflectance of the background. That is,
Received light amount of reflected light from an object that has entered the detection area,
When the received light amount of the reflected light due to the background is almost equal,
As shown in FIG. 11C, the rate of change in the amount of received light is so small that the presence or absence of an intruding object cannot be detected. That is, FIG.
As shown in FIG. 2, the background a and the object b have different relationships between the distance and the received light amount according to their respective reflectances, but the background and the object have a specific distance relationship as shown by a broken line. When there is no change in the amount of received light, such a positional relationship is called a dead zone. Also,
When infrared rays from the light projecting means are projected onto the open space, no reflection occurs due to the background, but as shown in FIG. 13, the object O passing a distance farther than the detection area D is shown.
11 has a high reflectance (for example, the body of an automobile or a window glass), the rate of change in the amount of received light is as shown in FIG.
There is a problem in that the same change as in (b) is shown, resulting in false alarms.

Because of the various problems described above, when using an object detector that detects an intruding object based on the amount of reflected light, the background color and reflectance are taken into consideration, and an object with a large reflectance is detected. It is necessary to satisfy the constraint condition that the detector is installed so that the detection area is set in a direction in which it does not pass through or an object having a high reflectance is not placed. In short, even when an object is detected based on a change in the amount of received light of reflected light, there is a problem that the installation place of the detector is restricted and the installation place is limited.

An object of the present invention is to solve the above-mentioned problems, and an object thereof is to provide a range-finding type intruder detector in which restrictions on the installation place are relaxed.

[0009]

In order to achieve the above object, in the invention of claim 1, a light projecting means for projecting a light beam to a detection area and a reflection of the light beam by an intruder into the detection area. Light is collected by the light-receiving optical system and a focused spot is formed on the light-receiving surface of the position sensor placed on the image plane of the light-receiving optical system, and it is displaced on the light-receiving surface of the position sensor according to the distance to the intruder. The light receiving means for outputting a position signal corresponding to the position of the focused spot, the distance calculating means for obtaining the distance to the intruder based on the position signal, and the distance to the intruder obtained by the distance calculating means is a predetermined distance. When it is within the range, it is provided with a notification determination means for determining that an intruder is present in the detection area and outputting a notification signal.

According to the second aspect of the present invention, the light projecting means for projecting the light beam to the detection area and the light receiving optical system for collecting the reflected light of the light beam by the intruder into the detection area by the light receiving optical system. A focused spot is formed on the light receiving surface of the position sensor placed on the image plane of the system, and a position signal corresponding to the position of the focused spot that is displaced on the light receiving surface of the position sensor according to the distance to the intruder is output. Light receiving means, distance calculating means for obtaining the distance to the intruder based on the position signal, and presence determining means for outputting the presence signal when the distance to the intruder obtained by the distance calculating means is within a predetermined distance range. And a movement determination means that outputs a movement signal when the distance to the intruder obtained by the distance calculation means changes more than a predetermined distance within a unit time, and it is detected that the presence signal and the movement signal are output at the same time. Enter the area Than it is and a notification determination means for outputting a notification signal determination to those that are.

According to a third aspect of the present invention, a light projecting means for projecting a light beam to the detection area and a light receiving optical system for collecting the reflected light of the light beam by an intruder into the detection area by the light receiving optical system. A focused spot is formed on the light receiving surface of the position sensor placed on the image plane of the system, and a position signal corresponding to the position of the focused spot that is displaced on the light receiving surface of the position sensor according to the distance to the intruder is output. Together with the light receiving means for outputting a light receiving signal corresponding to the total received light amount, the distance calculating means for obtaining the distance to the intruder based on the position signal, and the distance to the intruder obtained by the distance calculating means is within a predetermined distance range. Presence determination means that outputs a presence signal when the above condition is satisfied, movement determination means that outputs a movement signal when the total received light amount changes to a predetermined light amount or more within a unit time based on the received light signal, and the presence signal and movement Same as signal Than it is and a notification determination means for outputting a notification signal determines that there are intruder and the detection area is output to.

[0012]

According to the first aspect of the invention, since the information on the distance of the intruder is obtained based on the position signal output from the light receiving means, it is affected by the background and the color and reflectance of the intruder. Instead, it is possible to detect an intruder within the set predetermined distance range. In other words, since there is no need to consider the color and reflectance of the background, there are no restrictions on the background,
In addition, since the range of distances to be detected can be limited, even if an object having a high reflectance passes outside the detection area, an erroneous alarm does not occur, and there is an advantage that there are few restrictions on the installation place. In addition, this type detects an intruder existing within a predetermined distance range, so if it is used for automatic door opening / closing control, the state of opening the door when the person trying to pass through the door stops near the door Further, if it is used to control the blinking of the light in the show window, the light can be kept in a lighting state while a person stands in front of the show window.

According to the second aspect of the present invention, the information on the distance to the intruder obtained based on the position signal output from the light receiving means is used to determine whether the intruder is within a predetermined distance range. , And whether the intruder is moving or not, the notification signal is output only when the intruder is within a predetermined distance range and is moving. The intruder can be detected without being affected by the background or the color or reflectance of the intruder, and the restrictions on the installation location are reduced.

According to the third aspect of the invention, it is determined whether or not the intruder exists within a predetermined distance range based on the position signal including the distance information to the intruder output from the light receiving means. When the intruder is within a predetermined distance range and is moving, it is determined whether or not the intruder has moved based on the light reception signal corresponding to the total amount of light received by the light receiving means. Since the notification signal is output only to, even if it is determined that the intruder has moved due to a change in the total amount of received light when an object with a large reflectance passes outside the detection area,
Since the detection area is limited by the distance range, the notification signal is not output depending on the object outside the detection area, and false alarm can be prevented. That is, even if the detection area is set to the open space, no false alarm occurs, and there is an advantage that restrictions on the installation location are reduced.

[0015]

【Example】

(Embodiment 1) As shown in FIG. 1, the light projecting means 1 comprises a light emitting element 12 composed of a light emitting diode, and a light projecting optical system 11 for forming a light beam by the light output of the light emitting element 12. The light emitting element 12 is driven to blink by the output of the light emitting circuit 14 which receives the clock pulse output from the oscillation circuit 13, and the light beam projection timing is set by the clock pulse.

The reflected light diffused and reflected by the intruder 9 entering the detection area is condensed through the light receiving optical system 21 to form a condensed spot on the image plane of the light receiving optical system 21, and the light receiving optical system 21. The light is received by the position sensor 22 which is disposed on the image surface of the above and constitutes the light receiving means 2 together with the light receiving optical system 21. A PSD is used for the position sensor 22, and a pair of position signals I ₁ and I ₂ corresponding to the position of the focused spot are output. Here, the projection optical system 11 and the reception optical system 2
1 is disposed on the same plane, and the light receiving surface of the position sensor 22 is orthogonal to the optical axis of the light receiving optical system 21.
Since each of the position signals I ₁ and I ₂ is a current signal, the position signals I ₁ and I ₂ are converted into voltage signals V ₁ and V ₂ by the current-voltage conversion circuits 23a and 23b, respectively, and then input to the distance calculation means 3 composed of an integrated circuit. A distance signal corresponding to the distance to the intruder 9 is output. A clock pulse from the oscillation circuit 13 is input to the distance calculation means 3 and is controlled in synchronization with the light beam projection timing. By removing unnecessary signals that do not correspond to the light beam and processing them, The noise-to-noise ratio is improved. The distance signal is input to the notification determination means 4 having a microcomputer as a main component.
The notification determination means 4 includes a reference distance data setting unit 41 that provides a reference distance that defines a detection area, and a determination circuit 42 that compares the distance corresponding to the distance signal with the reference distance.
And a clock signal generation circuit 43 that supplies a reference clock signal to the determination circuit 42. When the reference distance is one, the determination circuit 42 sets the detection area within the reference distance or above the reference distance, and when the distance (distance signal) with the intruder 9 is within the detection area, the notification signal is sent. It outputs and drives the display circuit 5, or controls other devices through the output circuit 6. When there are two reference distances, the determination circuit 42 sets the area between the two reference distances as the detection area, and outputs a notification signal when the distance corresponding to the distance signal is between the two reference distances.

Now, the triangulation method using PSD adopted as the distance measuring method in this embodiment will be described. The basic configuration for distance measurement is as shown in FIG. 2, in which a light beam is emitted from the light projecting means 1 onto the object O, and the diffuse reflection light thereof is condensed by the light receiving optical system 21. At the same time, the focused spot formed on the image plane of the light receiving optical system 21 is PSD
The light is received by the position sensor 2. Position sensor 2
An element 2 obtains an electric signal corresponding to the position of the focused spot, and the distance to the object O is calculated based on the electric signal based on a triangulation method. That is,
If the position of the object O changes from A to B to C and the distance between the light projecting means 1 and the object O changes, the position of the focused spot formed on the light receiving surface of the position sensor 22 is a on the paper surface. → b →
By using PSD, which is a one-dimensional position detecting means capable of detecting the position on the paper surface, since it moves with c,
The distance to the object O can be detected.

As shown in FIG. 3, the PSD used as the position sensor 22 is a photovoltaic element having a pin structure and output electrodes E ₁ and E ₂ at both ends in the longitudinal direction. When the light spot P is irradiated, the high resistance layer p
The layer includes the irradiation position of the focused spot P and each output electrode E ₁ , E
_The output electrodes E ₁ , E are divided in inverse proportion to the distance from
_{From 2,} the output currents I ₁ and I _{2 obtained} by dividing the total current I are taken out. That is, the output current I _1, I ₂ from the output electrodes E _1, E ₂ is the resistance between the output electrodes E _1, E ₂ and Zs, division ratio of the p-layer is Z _1: if Z ₂ , I ₁ = (Z ₂ / Zs) · I ... I ₂ = (Z ₁ / Zs) · I. Now, if the distance from the electrode E ₁ to the focused spot P is x and the distance between the output electrodes E ₁ and E ₂ is L, then x = (Z ₁ / Zs) · L. , using the formula and formula, Z ₁ of the formula, Z
If s is eliminated and the distance x is expressed by using the output currents I ₁ and I ₂ and the distance L between the electrodes E ₁ and E ₂ , (1 / x) = {1+ (I ₁ / I ₂ ). } / L ... On the other hand, as shown in FIG. 2, if the distance between the optical axis of the light projecting means 1 and the output electrode E ₁ is BL and the distance between the position sensor 22 and the light receiving optical system 21 is F, then the light receiving optical system 21. Since the distance R from the object to the object O is R = BL · F / x ..., Substituting the formula into the formula gives R = {1+ (I ₁ / I ₂ )} · BL · F / L. .. Here, in the adjusted device, BL, F, and L are constants, so the distance R to the object O can be obtained by the output currents I ₁ and I _{2 of the} position sensor 22. That is, as described above, the output currents I ₁ and I ₂ of the position sensor 22 are input to the distance calculation means 3 and the above calculation is performed to obtain a distance signal corresponding to the distance to the object O. Can be done.

According to the above configuration, since the distance to the intruder 9 is determined and the notification signal is output, the presence or absence of the intruder 9 can be detected regardless of the background color and reflectance. Further, as shown in FIG. 4, if an intruder 9 enters the detection area at time t ₁ , a notification signal is output until the intruder 9 leaves the detection area at time t ₂ . .. Therefore, when it is used to control the opening and closing of the automatic door, or when it is used to control the lighting that lights up only when a person stands in front of the show window,
It is possible to prevent the inconvenience that the door is closed and the light is turned off while the person is in the detection area. Further, as shown in FIG. 5 (b), the timer for the off-delay operation for closing the door and turning off the light is set at time t ₂
In FIG. 5A, if the person is activated when the person leaves the detection area (FIG. 5A shows a state where the person enters the detection area at time t ₁ and the person leaves the detection area at time t ₂ ).
After a certain time T ₁ has passed, the door is automatically closed,
You can control to turn off the lighting.

(Embodiment 2) In the present embodiment, as shown in FIG. 6, existence determining means for outputting an existence signal when the distance to the intruder obtained by the distance calculating means 3 is within a predetermined distance range. 7 and a movement determination means 8 that outputs a movement signal when the distance to the intruder calculated by the distance calculation means 3 changes more than a predetermined distance within a unit time. The notification signal is output when the movement signal and the movement signal are obtained at the same time. The presence determination unit 7, the movement determination unit 8, and the notification determination unit 4 are mainly composed of a microcomputer. In the condition determination for generating the movement signal in the movement determination means 8, when the unit time is set to be relatively short, the distance difference between the start point and the end point of the unit time (that is, the rate of change of the distance) is used, or When setting the unit time relatively long, the difference between the maximum value and the minimum value of the distance within the unit time may be used. Since a human being is a detection target, the distance difference as a condition for generating the movement signal may be set to about 20 cm.

As described above, since the presence determining means 7 is provided, only the predetermined distance range can be set as the detection area, and the malfunction due to the reflected light from the outside of the detection area can be prevented as in the first embodiment. You can do it. Further, since the movement determining means 8 is provided, the notification signal is not output to an object that is stationary in the detection area, and in a place where many articles such as storefronts are placed. Even when it is used for notifying a visitor, there is an advantage that there is no restriction on the installation place.

By the way, in the existence judging means 7, the embodiment 1 is adopted.
Although it is usual to give a reference distance as in the case of the decision circuit 42, it may be troublesome to update the data in order to change the reference distance according to the installation conditions. Therefore, in this embodiment, as shown in FIG. 7, by moving the light receiving optical system 21 in a direction orthogonal to the optical axis (the position is indicated by a solid line and a broken line), the detection area is changed according to the installation conditions. To change. That is, the straight line connecting the center of the light receiving surface of the position sensor 22 and the center of the light receiving optical system 21 intersects the optical axis of the light projecting means 1 as the boundary distance of the detection area. In general, a detection area is set within a distance range closer to the light projecting means 1 than the boundary distance. In this case, in FIG. 7, the presence signal is output when the focused spot is formed below the center of the light receiving surface of the position sensor 22, and the presence signal is not output when the focused spot is formed above. In addition, the determination criterion of the presence determination means 7 may be fixedly set. When it is desired to change the boundary distance, the light receiving optical system 21 is moved, and the light receiving optical system 21 may be set closer to the light projecting unit 1 as the boundary distance is closer. By adopting such a configuration, the detection area can be changed only by adjusting the position of the light receiving optical system 21.
It should be noted that if the condition for generating the presence signal in the presence determination means 7 is reversed (that is, if the condition of the magnitude relationship of the distance for generating the presence signal is reversed), the detection area is located on the far side from the boundary distance. It is also possible to set to.

Other configurations and operations are similar to those of the first embodiment. (Third Embodiment) In the present embodiment, as in the second embodiment, when the intruder 9 exists in the detection area and the intruder 9 moves, a notification signal is output. .. However, in the second embodiment, the movement of the intruder 9 is detected based on the change in the distance within the unit time, but in the present embodiment, the intruder 9 is detected based on the change in the total amount of received light within the unit time. The difference is that the movement of is detected.

That is, when the total current of the position sensor 22 is used as a light receiving signal reflecting the total received light amount, and the movement determining means 8 changes the total received light amount to a predetermined light amount or more within a unit time based on the light receiving signal. It is designed to output a movement signal to. The movement determination means 8 adds the output voltages V ₁ and V ₂ of the current-voltage conversion circuits 23a and 23b to obtain a voltage output corresponding to the total received light amount, an addition circuit 81.
It is composed of a differentiating circuit 82 for differentiating the output voltage of the adding circuit 81 and a comparing circuit 83 for comparing the output of the differentiating circuit 82 with a predetermined reference voltage Vr. If the intruder 9 moves, the total received light amount of the reflected light changes, so that the output voltage of the differentiating circuit 82 increases. If this voltage exceeds the reference voltage Vr input to the comparing circuit 83, the comparing circuit The movement signal is output from 83. The movement signal thus obtained is treated in the same manner as the movement signal of the second embodiment, and when the presence signal and the movement signal are generated at the same time, the notification determination unit 4 outputs the notification signal. Of.

Other configurations and operations are similar to those of the second embodiment.

[0026]

According to the first aspect of the present invention, since the information on the distance of the intruder is obtained based on the position signal output from the light receiving means, it is affected by the background and the color and reflectance of the intruder. Instead, it is possible to detect an intruder within the set predetermined distance range. In other words, since there is no need to consider the color and reflectance of the background, there are no restrictions on the background,
In addition, since the range of distances to be detected can be limited, even if an object having a high reflectance passes outside the detection area, an erroneous alarm does not occur, and there is an advantage that there are few restrictions on the installation place. In addition, this type detects an intruder existing within a predetermined distance range, so if it is used for automatic door opening / closing control, the state of opening the door when the person trying to pass through the door stops near the door When used to control the blinking of the light in the show window, the effect is that the light can be kept in the lighted state while a person stands in front of the show window. ..

According to a second aspect of the present invention, the information on the distance to the intruder obtained based on the position signal output from the light receiving means is used to determine whether or not the intruder is within a predetermined distance range. It is used for two types of determination, that is, whether the intruder is moving or not, and outputs a notification signal only when the intruder is within a predetermined distance range and is moving. Since the intruder can be detected without being affected by the color or reflectance of the intruder, there is an advantage that there are less restrictions on the installation place.

According to a third aspect of the present invention, it is determined whether the intruder is within a predetermined distance range based on the position signal including the distance information to the intruder output from the light receiving means. It is determined whether or not the intruder has moved based on the received light signal corresponding to the total received light amount of the means, and only when the intruder is within a predetermined distance range and is moving. Since a notification signal is output, even if it is determined that an intruder has moved due to a change in the total amount of received light when an object with a high reflectance passes outside the detection area, the detection area must be limited by the distance range. As a result, the notification signal is not output depending on the object outside the detection area, and false alarms can be prevented. That is, even if the detection area is set to the open space, no false alarm occurs, and there is an advantage that restrictions on the installation location are reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment.

FIG. 2 is an explanatory diagram of a concept related to a distance measuring method according to an embodiment.

FIG. 3 is an operation explanatory diagram of the PSD used in the embodiment.

FIG. 4 is an operation explanatory diagram of the first embodiment.

FIG. 5 is an operation explanatory diagram of the first embodiment.

FIG. 6 is a block diagram showing a second embodiment.

FIG. 7 is a schematic configuration diagram showing a usage example of the second embodiment.

FIG. 8 is a block diagram showing a third embodiment.

FIG. 9 is a schematic configuration diagram showing a conventional example.

FIG. 10 is a perspective view showing a usage example which causes a problem in the conventional example.

FIG. 11 is an operation explanatory diagram of a conventional example.

FIG. 12 is an operation explanatory diagram of a conventional example.

FIG. 13 is an explanatory diagram showing a problem of the conventional example.

[Explanation of symbols]

 1 Light emitting means 2 Light receiving means 3 Distance calculation means 4 Notification determination means 5 Display circuit 6 Output circuit 7 Presence determination means 8 Movement determination means 9 Intruder

Claims (3)

[Claims] 1. A light projecting means for projecting a light beam to a detection area, and a reflected light of the light beam by an intruder into the detection area is condensed by an optical system for receiving light to an image plane of the optical system for receiving light. A light receiving unit that forms a focused spot on the light receiving surface of the position sensor and outputs a position signal corresponding to the position of the focused spot that is displaced on the light receiving surface of the position sensor according to the distance to the intruder. Distance calculating means for obtaining the distance to the intruder based on the signal, and when the distance to the intruder obtained by the distance calculating means is within a predetermined distance range, it is determined that the intruder is present in the detection area and notified. A distance-measuring intruder detector, comprising: a notification determining unit that outputs a signal. 2. A light projecting means for projecting a light beam to a detection area, and a reflected light of the light beam by an intruder into the detection area is condensed by a light receiving optical system and is focused on an image plane of the light receiving optical system. A light receiving unit that forms a focused spot on the light receiving surface of the position sensor and outputs a position signal corresponding to the position of the focused spot that is displaced on the light receiving surface of the position sensor according to the distance to the intruder. Distance calculating means for calculating the distance to the intruder based on the signal, presence determining means for outputting a presence signal when the distance to the intruder obtained by the distance calculating means is within a predetermined distance range, and distance calculating means The movement determining means that outputs a movement signal when the distance to the intruder obtained by the method changes more than a predetermined distance within a unit time, and if the presence signal and the movement signal are simultaneously output, the intruder enters the detection area. It is judged that there is A distance-measuring intruder detector, comprising: a notification determining unit that outputs a notification signal. 3. A light projecting means for projecting a light beam to the detection area, and a reflected light of the light beam by an intruder into the detection area is condensed by a light receiving optical system and is then formed on an image plane of the light receiving optical system. A focused spot is formed on the light-receiving surface of the position sensor placed, and a position signal corresponding to the position of the focused spot that is displaced on the light-receiving surface of the position sensor according to the distance to the intruder is output and the total received light amount is also output. Present when the light receiving means for outputting the corresponding light receiving signal, the distance calculating means for obtaining the distance to the intruder based on the position signal, and the distance to the intruder obtained by the distance calculating means are within a predetermined distance range. Presence determination means for outputting a signal, movement determination means for outputting a movement signal when the total amount of received light changes based on the received light signal over a predetermined amount of light within a unit time, and the presence signal and the movement signal are output simultaneously Detected A distance-measuring intruder detector, comprising: a notification determining unit that determines that an intruder is present in the area and outputs a notification signal.