JPH0690284B2 - Human body detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to, for example, an automatic door opening / closing device that automatically opens and closes a door by detecting that a human body approaches or separates from the door. The present invention relates to a human body detection device used.

[Conventional technology]

The automatic door opening / closing device has a human body detection device that detects that a human body has entered the detection area and that the human body has gone out of the detection area, and the door opening / closing drive device is based on the human body detection signal sent by the human body detection device. Is configured to operate. This human body detection device includes a light emitter and a light receiver, and a light blocking type that detects the human body by the fact that the human body blocks the infrared light emitted from the light projector, and the reflected light from the human body of the infrared light emitted from the light projector. There is a light-reflecting type that detects that a light receiver has entered the human body detection irradiation area.

As a device using this light reflection type detection device,
There is one disclosed in JP-A-61-284689. The human body detection method disclosed here is to mount an infrared projector and a receiver and an emitter / receiver composed of a signal processing circuit above the door, that is, in the ceiling of the entrance / exit of the building, and direct it from the projector to the floor in front of the door. Infrared rays are emitted so that a predetermined area in front of the door on the floor is illuminated, and the output of the photodetector that forms a detection area in the illumination area with this illumination area as a field of view is processed by a signal processing circuit to process the human body. The signal processing circuit performs detection, but when the human is not present in the detection area, the integrated value of the output of the light receiver (hereinafter referred to as the floor level) when the human is not present in the detection area, and when the human enters the detection area A deviation from the integrated value of the output of the light receiver is detected, and a human body detection signal is transmitted when the deviation continuously exceeds a threshold value for a predetermined time.

[Problems to be solved by the invention]

By the way, in coffee shops and the like, as shown in FIG.
The mat 82 is often placed on the outside of the mat, but since the mat 82 is naturally placed in the irradiation area A of the infrared rays R, the amount of light reflected from the floor changes. Therefore, if the mat 82 is placed after the threshold is set in the human body detection device 83, the deviation exceeds the threshold depending on the magnitude of the reflected light amount of the mat 82, and the door 81 opens. Something happens.

Each time such a malfunction occurs, it is necessary to reset the threshold value, but with the above-mentioned conventional one, this work is very troublesome.

This invention has been made to solve the above-mentioned conventional problems, and when a stationary object other than the human body is placed in the detection area, it is automatically distinguished from the human body and detected.
An object of the present invention is to provide a human body detection device capable of updating the determination standard of the detection area to a determination standard corresponding to a new environment.

[Means for solving problems]

In order to achieve the above object, the present invention shares a light projecting portion having a light projecting element row of light projecting elements arranged in a lateral direction and an irradiation area of each light projecting element of the light projecting element row to the floor surface. A light-receiving unit having a light-receiving element array of light-receiving elements paired with the light-projecting element so as to define a detection area in a portion including an irradiation area and an overlapping irradiation space including a floor surface; The detection control device has a detection control device that determines the presence or absence of a human body by synchronously and cyclically controlling a set of a light emitting element and a light receiving element that define a detection area, and capturing the received light amount. , Compare the received light amount that has been taken in with the corresponding judgment standard that was initially set, and if this received light amount is outside the judgment standard, execute the operation to create a human body detection signal. Outside and constant for a certain period of time and still If the object may be on the floor surface, at least one light receiving element of the set is synchronized with another light emitting element adjacent to the light emitting element of the set, and the overlapping irradiation space does not include the floor surface. When a new detection area is formed, and it is determined that the amount of light received from the new detection area is within the corresponding criterion and the stationary object is on the floor,
It is configured to update the above determination criteria for the detection area including the floor surface.

[Action]

According to the present invention, when the amount of received light exceeds the criterion, if the amount of received light is constant for a certain period of time, the lower end of the detection area is changed to a detection area that terminates at a predetermined height from the floor, and the change is made. When the detection operation is performed on the detection area, and the amount of received light at this time is within the corresponding determination criteria, it is determined that the object that has entered the detection area before the change is a stationary object other than the human body, such as a mat, It is determined that the operation for obtaining a new criterion for the detection area is started.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, A is a light emitting part, B is a light receiving part, 10 is a light emitting element switching switch, 11 is a light receiving element switching switch, 12 is a light receiving signal amplifier, and 13 is a sample hold circuit. 15 light emitting and receiving devices 14 are configured.

Reference numeral 20 is a detection control device, which is a micro computer (CP
U) 21, program memory (ROM) 23, data memory (RA
M) 22, an interface circuit (PIO) 24, and a detection control section and an A / D conversion section 25. The program memory 23 stores the reference value setting program shown in FIG. 5, the detection program shown in FIG. 6, and the stationary object detection program shown in FIG. Reference numeral 31 is an on-timer, 32 is a relay for creating a door opening / closing command signal, and 33 is a door opening / closing drive device.

As shown in FIG. 2, the light projecting section A comprises a plurality of light projecting elements 1 to 8 arranged in a row on the back of the light projecting lens 9 in a row.
Light projecting element 1-8 is irradiated with infrared rays R on the floor surface toward the optical axis to the floor surface F of the door front, as shown in FIG. 3 (a) and (b), classification irradiated region C ₁ ~ The irradiation area C consisting of C ₈ is the floor surface F
It is defined above. The group of the light projecting elements 5 to 8 shares the door side half of the irradiation area C (referred to as the latter half of the irradiation area), and the light projecting elements 1 to
Reference numeral 4 shares the first half of the irradiation area C (referred to as the first half of the irradiation area). The light receiving section B is, as shown in FIG.
Back a plurality of light receiving elements 1A~8A to the, now collectively arranged in two rows each of the optical axis toward the central portion of the partition irradiated region C ₁ -C _8, each light emitting element 1-8 The detection areas S _{11 to} S ₈₈ indicated by diagonal lines in FIGS.
(However, S _{55 to} S ₇₇ are not shown).

The light projecting elements 1 to 8 receive a drive signal (for example, a frequency of 3.5 KHz) via the light projecting element switching switch 10, and repeatedly emit infrared rays R having a pulse waveform as shown in FIG. 4 (a). The light receiving signal (shown in FIG. 4 (b)) V _L sent from the learning elements 1A to 8A is taken out through the light receiving element switching switch 11,
After being amplified by the amplifier 12, it is input to the sample old circuit 13. The light emitting element switching switch 10 receives the switching signal Sw and inputs the drive signal P to the light emitting elements 1 to 8 in this order cyclically and at high speed to input the light receiving element switching switch 11.
Receives the switching signal Sw and switches the light receiving elements 1A to 8A to the amplifier 12 in synchronization with the switching of the light projecting elements 1 to 8 respectively. The sample and hold circuit 13 receives the sample and hold signal S / H, and samples and holds the maximum level V _LMAX of the incoming light receiving signal (pulse signal) V _L. The A / D converter 25 converts the hold value V _LMAX of the sample hold circuit 13 into a digital value and inputs it to the CPU 21.
The drive signal P, the switching signal Sw, and the sample hold signal S / H are sent from the CPU 21 by turning on a power switch (not shown), and are supplied to the light projecting / receiving device 14 through the interface circuit 24.

Next, the operation of this device will be described.

When the above power switch is turned on, the CPU2 of the detection control device 20
1, the light projecting elements 1 to 8 sequentially emit infrared rays R,
Sequentially sends the light reception signal V _L level which is proportional to the amount of reflected light by receiving the reflected light RL from the detection area S ₁₁ to S ₈₈ operates synchronously with the light emitting element 1-8 each receiving element 1A~8A is To do.
Hereinafter, for convenience of explanation, a detection area S _{11 formed} by a set of the light projecting element 1 and the light receiving element 1A driven in synchronization will be described.

1 Reference value setting operation (Refer to the reference value setting program) When the power is turned on, execution of the reference value setting program is automatically started. This program detects the detection area S
_{Let 11} run in an environment where no humans exist. A / D converter 2
5 is the first of the received light signals V _L sequentially sent from the light receiving element 1A
The 2nd pulse, the 2nd pulse ... The maximum level value VLMAX of the nth pulse (however, n = 4 in this example)
Is converted into a digital value and sent to the CPU 21. CPU21 is the nth
When the maximum level value V _LMAX of the th pulse is digitally converted, the average value N of the n digital values D ₀₁ , D ₀₂ , ... D _0n
10 is calculated, threshold values σ _u and σ _d are provided above and below the average value N ₁₀ as the reference value of the detection area S ₁ , and the determination reference K
₁₁ (N ₀₁ −σ _d ≦ K ₁₁ ≦ N ₀₁ −σ _u ) is set and stored in the detection area S ₁₁ address of the data memory 22. This reference value setting routine is similarly executed for the detection areas S _{11 to} S ₈₈ , the respective determination criteria K _{22 to} K ₈₈ are set, and the detection area S in the stationary object detection operation described later is performed.
_The same applies to ₁₂ , S ₂₃ , S ₃₄ , S ₅₆ , S ₆₇ , and S ₇₈ , and the respective judgment criteria K ₁₂ , K ₂₃ , K ₃₄ , ... K ₆₇ , K
₇₈ is set.

II Detection Operation (Refer to Detection Program) After the reference value setting operation is completed, the detection program shown in FIG. 6 is sequentially executed for the detection areas S _{11 to} S ₈₈ .
The detection area S ₁₁ will be described below.

The A / D converter 25 converts the maximum level value V _LMAX of the pulse of the received light signal V _L into a digital value, and the CPU 21 converts the maximum level of n (n = 4) pulses, as in the reference value setting operation. When the value is digitally converted, n (n = 4) digital values
The average received light amount N ₁₁ is calculated by averaging D ₁₁ , D ₁₂ , ... D _1n , and it is determined whether or not the average received light amount N ₁₁ is outside the criterion K ₁₁ . When it is within the judgment standard K ₁₁ , the average light receiving amount calculation operation is repeated on condition that the relay 32 is deenergized and the door opening / closing command signal Y disappears.

If the average amount of received light N ₁₁ is outside the criterion K _11, it is necessary to check whether or not the average amount of received light ₁₁ is affected by disturbances such as sunlight and instantaneous flying objects. The same detection routine is repeated. That is, the CPU 21 has the next 2n (n
= 4) pulse digital values are averaged to calculate the average received light amount N ₁₂ . In this case, abnormally large or small digital values are excluded as those due to the disturbance or AC component, and the remaining digital values are averaged. Next, it is determined again whether this average received light amount N ₁₂ is outside the criterion K _11, and if it is still outside the criterion K _11, it is necessary to confirm whether or not it is affected by the ambient light. , The third detection routine is repeated, and the CPU21
Calculates the average received light amount N ₁₃ by averaging the digital values of the subsequent 2n (n = 4) pulses. Also in this case, the abnormally large or small digital value is excluded, and the remaining digital values are averaged. The CPU 21 uses this average received light amount N ₁₃ as the average received light amount N ₁₂ obtained in the second detection routine.
If they match or approximate to each other,
The human body detection signal X is sent to the relay 32 when it is judged that a human has entered the detection area S ₁₁ . As a result, the relay 32 is energized (turned on).

III Static Object Detection Operation The CPU 21 determines whether the human body detection signal X is generated by the human body or a stationary object other than the human body such as a mat. After the above operation, it is checked whether the average received light amount N ₁₃ of the detection area S ₁₁ is substantially constant for a predetermined time T _K (for example, about 20 seconds). If it is not constant, the human body detection signal is detected. The on-timer 31 is set by judging that the generation of X is due to the human body. If it is constant, the light receiving element that operates in synchronization with the light projecting operation of the light projecting element 1 is changed to the light receiving element 2A, and a new detection area S ₁₂ is provided as shown in FIG. 3 (c). . The detection area S ₁₂ is a detection area whose lower end is located at a predetermined height H from the floor surface, and the detection area S ₁₂ is not reached by the reflected light of a stationary object such as a mat placed on the floor surface. Next, the light emitting element 1 and the light receiving element 2A are caused to perform light _emitting and receiving operations n times (n = 4), and the average light receiving amount N _K12 is calculated. This average received light amount N _K12 is the criterion
If it is within K ₁₂ , then the light emitting element 2 and the light receiving element 3A
To form the detection area S _23, and to cause the light emitting element 2 and the light receiving element 3A to perform light emitting and receiving operations n times, and to calculate the average light receiving amount.
Calculate N _K23 . When this average received light amount N _K23 is within the criterion K ₂₃ , the light projecting element 3 and the light receiving element 4A are selected,
A detection area S ₃₄ is formed, the light projecting element 3 and the light receiving element 4A are caused to perform light projecting and receiving operations n times, and the average amount of received light N _K34 is calculated and compared with the determination reference K ₃₄ . This routine is
The light emitting element 5 and the light receiving element 6A, the light projecting element 6 and the light receiving element 7A, and the light projecting element 7 and the light receiving element 8A are executed, and the average light receiving amount in each routine is within the judgment criteria K ₅₆ , K ₆₇ , and K ₇₈ . At this time, it is determined that a stationary object such as a mat is placed on the floor surface of the irradiation area C, the reference value setting operation of I is performed, and each detection area S _{11 to} S ₈₈ and S _{12 to} S ₇₈ The reference value of is updated and a new criterion is set.

As described above, in the present embodiment, the combination of the light emitting element and the light receiving element whose light emitting and light receiving operations are controlled in a synchronous manner is changed so that the floor surface is located above the floor surface. A new detection area that is hardly affected by the reflected light from the stationary object above is defined, and when the reflected light amount from the detected area is within the corresponding criterion, the stationary object is on the floor surface. judge. This is because if the human body has a height (height) even if the detection area is set to a high area apart from the floor surface, it reaches the detection area.

In the present embodiment, a new detection area is set by changing the combination of the light emitting element and the light receiving element that are operated in synchronization. Whether or not to make the above change depends on the amount of light received during a normal detection routine. If the criterion exceeds the criterion, it is determined after a certain time, so the distinction between the human body and the stationary object is prompt, and
Done exactly.

In the above-mentioned embodiment, the light projecting section A and the light receiving section B are composed of the light projecting elements and the light receiving elements arranged in two rows, but it goes without saying that they may be arranged in one row.

Further, the arrangement of the light projecting element and the light receiving element may be an array that can form a detection area that is apart from the floor surface by a predetermined height by changing the combination.

Further, in the above embodiment, the determination standard is set for each detection area, but the determination standard may be commonly set for each detection area.

Further, in the above embodiment, six new detection areas including the detection areas S ₁₂ , S ₂₃ , and S ₃₄ are formed, and the stationary object detection routine is executed 1 for all of them. S ₂₃ or left and right detection areas S ₁₂ , S ₃₄
It is also possible to execute one of the above and make a determination based only on the result.

Further, in this embodiment, since the human body detection is performed by software, there is an advantage that the configuration of the device is simplified.

〔The invention's effect〕

As described above, according to the present invention, when a detection signal is created, it is automatically determined whether the detection signal is caused by the human body or another stationary object, and the determination corresponding to the environmental change in the detection area due to the stationary object. Since the reference is created, even if a stationary object such as a mat is placed at the entrance, it is possible to prevent the trouble of manually setting the determination reference, and the determination is performed by newly setting the detection area. An accurate judgment can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing an arrangement structure of a light projecting element and a light receiving element in the above embodiment, and FIGS. 3 (a) to 3 (c) are detection areas. FIG. 4 (a) is an output waveform diagram of the light projecting element in the above embodiment, FIG. 4 (b) is an output waveform diagram of the light receiving element in the above embodiment, and FIG. 5 is a reference value setting in the above embodiment. FIG. 6 is a flow chart of the program in the above embodiment, FIG. 7 is a flow chart of the detection program of the stationary object in the above embodiment, and FIG. 8 is a block diagram of a human body detecting device using a conventional matt switch. 1-8 ... Emitter element, 1A-8A ... Receiving element, 10 ... Emitter switching switch, 11 ... Receiving element switch, 20 ...
… Detection control device, 21 …… CPU.

Claims (1)

[Claims] 1. A light projecting portion having a light projecting element row of light projecting elements arranged in series in a lateral direction, and an irradiation area sharing an irradiation area of a floor surface of each light projecting element of the light projecting element row, The detection area is defined with a light receiving section having a light receiving element row of light receiving elements paired with the light projecting element so that the detection area can be defined in a portion including overlapping floors in the irradiation space. And a detection control device that controls the set of the light emitting element and the light receiving element synchronously and cyclically, and captures the amount of received light to determine the presence or absence of a human body. Is compared with the corresponding determination standard that has been initially set, and if the received light amount is outside the determination standard, an operation to create a human body detection signal is executed. There may be a stationary object on the floor that is constant over time. If not, at least one light receiving element of the above group is synchronized with another light projecting element adjacent to the light projecting element of the group to form a new detection area which is an overlapping irradiation space and does not include the floor surface, When it is determined that the amount of light received from the new detection area is within the corresponding determination criteria and the stationary object is on the floor surface, the determination criteria for the detection area including the floor surface are updated. Characteristic human body detection device.