JPH01206484A - Number-of-persons detector - Google Patents

Abstract

PURPOSE:To prevent double counting and counting omission by detecting human bodies by different detection references, deciding the coincidence of a bearing in which the human body is detected in a short distance side visual field with a bearing in which the human body is detected in a long distance visual field and deciding the number of persons based on the detection result and the decision result of a bearing coincidence deciding part. CONSTITUTION:A judging part 5 contains a human body detecting part 51 able to detect the human bodies by different detection references L1 and L2, a bearing coincidence deciding part 52 to decide the coincidence of the bearing in which the human body is detected in a short distance side visual field Fa with the bearing in which the human body is detected in a long distance side visual field Fb, and a number-of-persons deciding part 53 to decide the number of persons based on the detection result of the human body detecting part 51 and the decision result of the bearing coincidence deciding part 52. When a certain detection reference L2 is used, by detecting the human body by the different detection reference L1(>L2) even when the human body in the same bearing in the short distance side visual field Fa and the long distance side visual field Fb is detected, the state in which the human bodies exist respectively in the respective visual fields Fa and Fb can be distinguished from the state in which one human body exist in both the visual fields Fa and Fb and the repeated counting and counting omission of the human bodies can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an infrared receiving type people detection device that detects the number of people by detecting infrared rays emitted from a detected human body.

[Prior Art] Fig. 10 is a block diagram showing the overall configuration of a conventional far and near field switching type people detection device (Japanese Patent Application No. 62298496), and Figs. A diagram showing the schematic configuration of the circular scanning optical system 1 used for
(b) is a diagram for explaining the field of view of this circular scanning optical system 1. As shown in the above countries, this people detection device includes an infrared detection element 2, a circular scanning optical system 1 that circularly scans the field of view of the infrared detection element 2, and a front end that amplifies the output signal of the infrared detection element 2. an amplifying section 3; a signal processing section 4 that converts the output signal of the preamplifying section 3 into a signal necessary for detecting the number of people; and a determining section 5 that determines the number of people 3 based on the output signal of the signal processing section 4; The circular scanning optical system 1 includes an output section 6 that outputs the number of people information from the output signal of the judgment section 5, and the circular scanning optical system 1 has a near-field field Fa close to the rotation center and a far-field field Fa far from the rotation center every half rotation. Fb and Fb are alternately switched for scanning. As shown in FIG. 11, the near-far field switching type circular scanning optical system 1 has two cylindrical mirrors 11.12 attached to a rotary plate 14, and 11.12 of each mirror 11.12. The line direction is parallel to the radial direction. Moreover, these two mirrors 11 and 12 are attached so that their respective generatrix lines form an angle of 180 degrees. Mirror 11 is rotation axis 1
The mirror 12 is mounted at a position close to the rotating shaft 15, and the mirror 12 is mounted at a position far from the rotation axis 15. The rotating shaft 15 of the rotating plate 14 is arranged on the field of view center C of the light receiving surface of the infrared detecting element 2, and is rotationally driven by the motor 13. The field of view on the floor obtained by this circular scanning optical system 1 is shown in Fig. 12(a).
, As shown in (b), there are two fields of view, Fa by the mirror 11 and Fb by the mirror 12. Also, the instantaneous field of view by each mirror 11.12 is Fao, F
It becomes bo. If the wall hanging type is used, please refer to Figure 12 (I).
), the left half of the field of view is hidden, so the only part that is effective as a detection range is the right half, resulting in a 180-degree semicircular field of view.

[Problems to be Solved by the Invention] In the double series of conventional technologies, the near field of view Fa and the far field of view Fb are adjacent to each other, and the field of view boundary line is not vertical. A human body standing near the boundary between the visual fields Fa and Fb is detected in both visual fields, and even though there is actually only one person, there is a possibility that two people will be detected.

Therefore, the direction in which the human body detection signal was obtained in the near field of view Fa and the direction in which the human body detection signal was obtained in the far field of view Fb were compared, and the direction in which the human body detection signal was obtained in each of the fields of view Fa and Fb was compared. If they match, calculate the number of times the directions match, and calculate the number of times the directions match from the sum of the number of people detected in the near field of view Fa and the number of people detected in the far field of view Fb. It has been proposed to calculate the number of people detected at the end of the song by subtracting the number of people.

In this way, it is possible to prevent a human body standing near the boundary between both visual fields Fa and Fb from being counted redundantly. However, the reason why the direction in which the human body detection signal was obtained in the near field of view Fa and the direction in which the human body detection signal was obtained in the far field of view Fb is necessarily the same is because there is a human body near the boundary between both fields of view Fa and Fb. Not only when present, both visual fields Fa and Fb
It is also possible that a human body z actually exists. In particular, when the above-mentioned number of people detection device is installed above the elevator door and used to detect the number of people waiting in the elevator, there are many cases where people are lined up in a line in the same direction. In such a case, it is inconvenient that the number of detected people is counted lower than the actual number.

The present invention has been made in view of these points, and its purpose is to switch the field of view obtained by a circular scanning optical system into a near-field field of view and a far-field field of view every half rotation. The object of the present invention is to enable a system for detecting the number of people to accurately determine the number of people when human bodies are detected in the same direction in both fields of view.

[Means for solving the problem] In the present invention, the above-mentioned section Mf! :To solve,
As shown in FIG. 1, an infrared detection element 2, a circular scanning optical system 1 that circularly scans the field of view of the infrared detection element 2, and a preamplifier 3 that amplifies the output signal of the infrared detection element 2; a signal processing section 4 for converting the output signal of the preamplifier section 3 into a signal necessary for detecting the number of people; a determining section 5 for determining the number of people based on the output section of the signal processing section 4;
The circular scanning optical system 1 includes an output section 6 that outputs the number of people information from the output signal of the section section 5, and the circular scanning optical system 1 has a field of view Fa on the near side near the rotation center and a far side field far from the center of rotation in a half-rotation sea. In the people detection device which uses an optical system that scans by alternately switching the field of view Fb, the judgment section 5 detects a large tree based on different detection standards.
, an azimuth matching determination unit 52 that determines whether the direction in which the human body is detected in the near-field side view Fn and the direction in which the human body is detected in the far-distance side view IFb matches, and the detection result of the human body detection unit 51 and the direction match determination unit 52 . This refers to a number of people determining section 53 that determines the number of people based on the determination result of the section 52.

[Operation] In the present invention, different detection criteria L,
, L 2 human bodies can be detected, so when a certain detection standard 1-2 'E' is used, the near field of view Fa
Even if a human body is detected in the same direction in the long-distance chick side field of view Fl+, by performing human body detection with different detection standards L l (> 12), it is possible to detect whether a human body exists in each view [Fa or Fb]. It is possible to distinguish between this state and the state in which a single human body is present across both visual fields Fa and Fb, and it is possible to prevent duplicate counting or omission of counting of human bodies.
Therefore, the error in detecting the number of people is reduced.

[Embodiment] FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, and FIG. 2 is a diagram for explaining the field of view of the circular scanning optical system 1 used in this embodiment.

In this embodiment, a field mask is added to the conventional circular scanning optical system 1 shown in FIG. 11 described above to obtain a fan-shaped field of view of 180 degrees or less. This is to prevent the mirrors 11 and 12 from simultaneously reflecting infrared rays from the human body. The infrared rays reflected by the mirror 11 or 12 in the circular scanning optical system 1 are transmitted to the infrared detection probe 2
The light is received and converted into an electrical signal. The output of the infrared detection element 2 is amplified by a preamplifier 3 and then sent to a signal processor 4.
is input. The signal processing unit 4 first inputs the input signal to a bandpass filter, removes unstable low frequency components and unnecessary high frequency components, and improves S/Nit. The output of the bandpass filter is A/D converted and sent to the judgment unit 5.
is input.

The synchronous borrow generator 16 monitors the rotation of the circular scanning optical system 1 and generates a pulse at the instant when the instantaneous field of view of the mirror 11 or 12 enters the detection range and at the instant it exits the detection range. A pulse 3 generated by the synchronous belief generator 16 is shown in FIG. The pulse P1 is the instantaneous field of view Fa of the mirror 11.

Pulse P2 is a pulse that is generated at the moment when the instantaneous field of view Fao exits the detection range. Further, the pulse P3 is a pulse generated at the moment the instantaneous field of view Fbo of the mirror 12 enters the detection range, and the pulse P4 is a pulse generated at the moment the instantaneous field of view FbO leaves the detection range. These pulses P1-P
By inputting , into the determining unit 5, the determining unit 5 can determine which field of view, far or near, the circular scanning optical system 1 is currently looking at.

1-11 section 5 is stored in memory in advance as an input waveform or a reference waveform when there is no human body in the detection area, and the input waveform is compared with the reference l) α waveform in the memory. Ru. In this embodiment, a comparison operation is performed between an input waveform and a reference waveform, and the result is newly set as a difference waveform. Regarding the difference waveform, a maximum loss point exceeding a predetermined level L2 is detected, and the detected maximum point 117JR is counted as the number of people. Here, the detection level L2 of the maximum point is set to a low level that allows detection if a part of the human body is within the field of view. When the number of detected people is 0, it is updated by the reference waveform or the input waveform.

In this embodiment, the functions of the determining section 5 are realized by a microcomputer program. Figure 4 (,
), (b) are flowchart 1 showing the processing contents of the judgment unit 5.
・It is. First, the pulse P1 from the synchronization signal generator 16
When detected, the point of detection is set as the zero break on the time axis, and
Let the variable representing time be t=0. Then, the input value from the signal processing section 11 to the judgment section 5 at that point is input to the array variable I.
Memory in a(L). The presence or absence of the pulse P2 from the synchronization signal generator 16 is determined, and if the pulse P2 is not detected, the variable t representing time is counted up, and the input value at that point is memorized in the array variable I n (t). . Similarly, L=0.1.2. ... as array variables I n (0), I a (1), I
a(2>, . . . ).In this way, the input waveform Ia(L) in the first viewing field Fa on the short distance side can be captured.

Note that since the motor 13 rotates at a constant speed during the scan 101, the variable [ is also a variable representing the scan angle.

When the pulse P2 from the synchronization signal generator 16 is detected,
The value of the variable at that time is memorized as the end time Ta, and a temporary stop signal P is sent to the motor 13. Next, an array variable Ra(L) indicating a reference waveform for the visual field Fa on the short distance chick side is read out from the memory, an array variable Ra(t)
is the value of the reference waveform on the short distance side in the case of L=0, 1, 2, -, Ta mino, which is stored in memory. Each time L=, 0, 1.2. ..., about T a, D
A differential calculation of a(t)'=I a(t)-Ra(L) is performed to obtain an array variable Da(t) indicating a differential waveform in the near field of view Fa. For the difference waveform obtained in this way, detect a maximum point exceeding a predetermined level L2,
The number of detected maximum points is n and the detection times are memorized as Lal~jan. 6If n=0, each time t-=-0
, 1, 2, -, Ta, the value of the array variable r a(t) is assigned to the array variable Ra(L), and the reference waveform is updated with the input waveform. Next, the motor 13 is started and waits until the pulse P3 from the synchronization signal generator 16 is detected.

When the pulse P is detected, the time of its detection is set as the zero point on the time axis, and the variable t representing time is set to 1=0. Then, the input value from the signal processing section 4 to the flJ cutting section 5 at that time is stored in the array variable Ib(t). The presence or absence of the pulse P4 from the synchronization signal generator 16 is determined by 1 degree, and if the pulse P4 is not detected t'L, D''t181 is counted up by k multipliers, and the input values at that point are arranged. Memory in variable 111 (L).Hereafter, in the same way, L=
0.1.2.・The input value in array variable I b(0
), Tl (1), IJ (2), etc. In this way, the input waveform r b (t) in the field of view F 13 on the far side can be captured.

When the pulse P4 from the synchronization signal generator 16 is detected,
The value of the variable at that time is stored in memory as the end time T IJ, and a temporary stop signal P is sent to the motor 13. Next, an array variable Rb(t) indicating a reference waveform for the far field of view F)+ is read out from the memory, an array variable R1
1(L) is L=0.1, 2. ..., the value of the reference waveform on the far side in the case of Tt+ is stored in memory. Each time L=0. I, 2. ..., About TLI, D
b(t) -I b(shi) -R, b(t)g] Perform a difference calculation to obtain an array variable Db(t) indicating the difference waveform in the field of view Fb on the long-distance identification side. For the difference waveform obtained in this way, the maximum points are counted and the detected number of maximum points is t.
o pieces, and the detection times are stored as tb and ~Lbm.

If end=0, each time t=o, 1.2. ..., Tb
, the value of array variable I b(t) is transformed into array variable Rb(
t) to update the reference waveform with the input waveform.

Next, between the number of maximum points detected on the near side (n) and the number of maximum points detected on the far side (m), the number k of the same human body that is counted twice is calculated. judge. The algorithm for determining the number of duplicate counts will be explained with reference to FIG. 4(b). First, a variable k indicating the number of recovery times is set to 0, and it is determined whether the detected number of local maximum points on the short distance side or the long distance side is 0 or m is O. Detection number 11 or 10 is 0
If so, it is impossible that duplicate counting is being performed, so the process ends with k=o. If both the detection numbers n and m are not O, the detection time tai(
i=1~n) and the detection time tbj(j-1~
m), and if there is a matching detection time, the level of the difference waveform Da (Lai) of the near field of view Fa at the detection time tai=Lbj and the same detection time La1-=t
Difference waveform Db (tb
j) is a predetermined level L + (> L
2) is exceeded. Here, level L.
is set at a high level that allows detection when most of the human body is included in the field of view. Da(
Lai):・L, and Db(Lbj)>Ll, the short distance chick i1"'I 1"A! I!
'F F a and appropriate pressure 1jii m'l IIQ field Fb
Since most of the human body is absorbed in both fields, is it different for both visual fields Fa and Fl+? The big tree? If there are 7, ゛('τ1 is fixed, and it is not considered as duplicate counting.

On the other hand, if the above conditions are not satisfied, it is determined that one human body is standing near the boundary 1.1 between the near field of view Fa and the far field of view F13, and a variable k indicating the number of times of repeated counting is determined.
Count up by one. Short distance ↓ Detection time L on the whistle side
a1 (i=1・~I+) and M when detected at long distance 1711
In all cases where '1Lbj (j=1 to m) match, it is determined whether the above condition is satisfied and zl is satisfied, and the number of times the above condition is not satisfied is set to 31 times and sent to Callan I.

Repeat count’! Returning to the flow shown in Fig. 4 (μ), the sum of the detection numerical number n of local maximum points on the short distance side and the number of detected minister points I11 on the long distance side, The true number of people M detected is determined by subtracting the weight 1 (the number of counts 1).

Next, the motor 13 is started and the process waits until the pulse P1 from the synchronizing signal generator 1G is detected, and the same operation is repeated thereafter.

Note that the output unit 6 is configured to display the number of people information given from the determination unit 5 and to transmit it to a remote point if necessary.

Next, the operation of this embodiment will be explained in terms of P1 by citing some examples. No. 5121(a) shows the human body Ma in each of the "fi" distance side field of view Fa and far distance side field of view Fl).

A case is shown in which Mb exists and the directions in which human bodies M a and M b exist are the same. In this case, the difference waveform on the short distance side becomes as shown in FIG. 6(a), and the difference waveform on the short distance side becomes as shown in FIG. 6(b).

FIGS. 5(b) and 5(c) show the near field of view Fa,
One human body M a , M only in the far field side Fb
The case where b exists is shown. In this case, the difference waveforms on the short distance side are shown in FIG. 7(a) and FIG. 8(a), respectively.
The difference waveforms on the appropriate pressure Liu side are as shown in FIG. 7 (1) and FIG. 8 (b), respectively.

FIG. 5(d) shows a case where one human body Me exists in a state spanning both the near field of view Pa and one far field of view Fb. In this case, the difference waveform on the near side becomes as shown in FIG. 9 (,), and the difference waveform on the far side h'F i'il becomes as shown in FIG. 9 (1'').

As mentioned above, in this embodiment, there are two levels of human body detection level L.
l, L2 (L, > L2), and the first level L
1 is set to be slightly below the peak level of the difference waveform of the field where most of the human body exists within the field of view, and the second level L2 is set to the peak level of the difference waveform of field 6 where a part of the human body exists within the field of view. It is set slightly below the level.

First, in FIG. 6, at the same detection time jai=tbj at which the difference waveforms arrive, difference waveforms larger than the first level L1 are obtained on both the short-distance side and the short-distance side. In this case, there is one human body M a in each of the fields of view FLI and Fll on the near-distance side and near-distance side, respectively.
It is determined that M b exists. Therefore, the number of people detected is two.

Next, in FIGS. 7 and 8, a difference waveform larger than the first level L1 occurs only on the 'fi distance side and the short distance side, and on the other hand, a difference waveform larger than the first level L1 occurs at the same location. A difference waveform 6 smaller than L is generated. In this case, it is determined that one human body penetrates only within the field of view on the side where a difference waveform larger than the first shield L1 occurs. Therefore, the number of people detected is one.

Furthermore, in FIG. 9, at the same detection time La1=Lbj in the difference waveform, the difference waveform is larger than the second level L2 and smaller than the first level L1 on both the short distance side and the short distance side. It is occurring. In this case, it is determined that one human body is present in the apparatus (astride the short-distance side and the side-view JFa, Fb of the short-distance side). Therefore, the number of people detected is one.

Further, although not particularly illustrated, a difference waveform larger than the first level L1 is generated on the short distance side and the short distance side,
On the other hand, a second level L2 smaller than the first level L1
If a difference waveform larger than 1 is generated, this corresponds to a case where most of the human body is included in one field of view and a part of the human body is included in the other field of view, so the number of detected people is determined to be 1. I am planning to do so.

In addition, in the embodiment, it is possible to use the level of the maximum point corresponding to the human body as the criterion for human body detection, or to use the magnitude of the slope before and after the maximum point as the criterion; It is also possible to use both methods as appropriate.

[Effects of the Invention] As described above, the present invention changes the field of view of the optical system for circularly scanning one field of the infrared detection element every half rotation between the near field near the center of rotation and the far field far from the center of rotation. In an infrared receiving type people detection device, human body detection is performed using the detection substrate of the stomach while alternating between the side field of view and the side field of view.
I person (↑(detection unit), an azimuth matching determination unit that determines whether the force position in which the human body is detected in the far side visual field and the direction in which the human body is detected in the far J Kyokan 1i2 field, and the human body detection unit. Since we have provided a number of people judgment section that judges the number of people based on the detection results of the section and the judgment results of the orientation matching judgment section, it is possible to detect the presence of a human body in each field of view on the near side and the appropriate pressure chick side, and on the side field of view. It is possible to distinguish between the state in which a single human body is present as if straddling the tree, and it has the effect of preventing duplicate counting and counting omissions of large trees.Therefore, it has the effect of reducing the number of people detection and errors. be.

[Brief explanation of the drawing]

1f"71 is a block diagram of an embodiment of the present invention, FIGS. 2(a) and (b) are a plan view and a side view showing the same field of view, respectively, and FIG. 3 is a synchronization signal generation used for the same. 4(a) and 4(b) are flowcharts for explaining the operation of the judgment section used in this embodiment, and FIG. 5 is a waveform diagram showing the output of the judgment section, and FIG. 6 to 9 are operation waveform diagrams of the same as above, FIG. 10 is a block diagram of the conventional example, and FIGS. 11(a) and (b) are front views of the circular scanning optical system used in the above, respectively. Figure and bottom view, Figure 12 (a
) and (b) respectively show the visual fields of the same as above.
tl'Koji [It is face I. 1 is a circular traveling light system, 2 is an infrared detection element, 3 is a preamplifier 1, 1 is a signal processing unit, 5 is a judgment unit, 6 is an output unit, 51 is a human body detection unit, and 52 is an orientation A coincidence determination unit, 53 is a number of people determination unit, Fu is a close-range side view] [I, Fb is an appropriate pressure side view.

Claims (1)

[Claims] (1) An infrared detection element, a circular scanning optical system that circularly scans the field of view of the infrared detection element, a preamplification section that amplifies the output signal of the infrared detection element, and an output signal of the preamplification section that It consists of a signal processing section that converts into a signal necessary for detection, a judgment section that judges the number of people based on the output signal of the signal processing section, and an output section that outputs the number of people information from the output signal of the judgment section, and the In the people detection device, the circular scanning optical system is an optical system that scans by alternately switching between a near field of view close to the center of rotation and a far field of view far from the center of rotation every half rotation, and the judgment section is configured to perform different detections. A human body detection unit capable of detecting a human body based on a reference, an azimuth matching determination unit that determines whether the direction in which the human body is detected in the near field of view and the direction in which the human body is detected in the far field of view match, and the human body detection unit. A number of people detection device comprising: a number of people determination section that determines the number of people based on a detection result and a determination result of an azimuth coincidence determination section.