JPH0799393B2 - Human body detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to, for example, an automatic door opening / closing device that detects that a human body approaches or separates from a door and automatically opens and closes 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 exited the detection area, and the door opening / closing drive device is activated by the human body detection signal sent by the human body detection device. It 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 reflection type that detects that a human body has entered the human body detection area by the fact that the light receiver receives the light.

As a method of using this light reflection type detection method,
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. The infrared ray is emitted so that a predetermined area in front of the door on the floor surface is illuminated, and the output of the light receiver is processed by a signal processing circuit to detect a human body. A person enters the detection area and the integrated value (reference level value) of the output (level signal) of the light receiver when there is no person in the detection area defined by the light receiver in the detection irradiation area. A deviation from the integrated value (detection value) of the output of the light receiver at that time is detected, and a human body detection signal is transmitted when the deviation continues for a predetermined time and exceeds a predetermined value.

[Problems to be solved by the invention]

That is, this conventional method is a method of detecting a human body on condition that the integrated value of the light receiving level of the light receiving device for receiving the reflected light has changed and the changed amount is equal to or larger than the set value. Entry into the area and exit from the detection area can be detected, but if a person is standing still in the detection area, the deviation will approach and the detection sensitivity will decrease over time, and the door will close. There is a problem of getting mad.

Further, in this conventional technique, the deviation is, for example, 20
If it shrinks in seconds, the door will close if a person has stopped for 20 seconds, and then the reference level value will be the value when that person stopped, so even if that person disappears, There is a problem when the door remains open for a certain period of time due to a deviation between the new reference level value and the detected value on the floor surface. With this conventional technique, stationary detection is practically impossible. Atsuta

The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a human body detection device that can reliably detect a human even when the human is stopped in the detection area. .

[Means for solving problems]

In order to achieve the above object, the present invention provides a projector for projecting infrared rays in a pulse shape to define an irradiation area for human body detection, and a detection area within the irradiation area for reflecting light from the detection area. And a detection control device for controlling the above-mentioned light emission and light reception and for determining the presence or absence of a human body by controlling the above light emission and light reception, and the detection control device repeats the above light emission a predetermined number of times, The average amount of received light is calculated based on the received amount of light of this predetermined number of times, and when the average amount of received light is outside the threshold value set in the initially set determination criterion, the average amount of received light is calculated again and An operation for creating a human body detection signal is performed through a confirmation operation for comparing with a threshold value, and the above-mentioned initial determination criterion is the predetermined number of times of light reception of the light receiver when there is no detection target in the detection area. Flat based on quantity It is obtained by configured to be created.

Then, the confirmation operation has an operation of not calculating the abnormal light receiving amount and calculating an average light receiving amount, and an operation of comparing the current average light receiving amount with the previous average light receiving amount for this average light receiving amount. preferable.

[Action]

In the present invention, since the presence or absence of the human body is detected based on the current amount of light received by the light receiver when the detection target is absent, the reference does not change even when the human body is stopped in the detection area.
As long as the human body is in the detection area, the human body detection signal is generated. In addition, an instantaneous disturbance such as a flying object is distinguished by the confirmation operation in which the human body is detected again by calculating the average amount of received light.

Then, the confirming operation has an operation of calculating the average light receiving amount by not including the abnormal light receiving amount, and an operation of comparing the current average light receiving amount with the previous average light receiving amount with respect to this average light receiving amount, Disturbances such as variations in the detection operation of the device are eliminated.

〔Example〕

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

In FIG. 1, 1 is a projector, 2 is an amplifier, and 3 is an oscillator. The oscillator 3 oscillates a drive signal of a predetermined frequency (for example, 500 Hz), and the drive signal is amplified by the amplifier 2 and supplied to the projector 1. The projector 1 emits infrared light having a pulse waveform as shown in FIG. 2 (a). Fire R repeatedly. The emitted infrared rays R illuminate, for example, a predetermined area in front of an automatic door (not shown). Reference numeral 4 denotes a light receiver, which divides a detection area A into an irradiation area formed by the infrared rays R from the light projector 1, and its output V _L is amplified by an amplifier 5 and then guided to an A / D converter 6. Reference numeral 7 is a detection control circuit, which constitutes a detection control device together with the A / D converter 6, and is a microcomputer (CP).
U) 8, program memory (ROM) 9, data memory (RA
M) 10 and an interface circuit 11, and the program memory 9 stores the reference value setting program shown in FIG. 3 and the detection program shown in FIG. 12 is an on-timer, 13 is a relay for creating a door opening / closing command signal,
14 is a door opening / closing drive device.

Next, the operation of this device will be described.

When the device power is turned on, the CPU 8 of the detection control circuit 7 operates to send an oscillation command to the oscillator 3, the oscillator 3 starts sending a drive signal, and the projector 1 starts projecting infrared rays R. The light receiver 4 which receives the reflected light _RL from the floor or the like in the detection area A or a person sends out a received light signal _VL (shown in FIG. 2B) at a level proportional to the amount of reflected light.

I Reference Value Setting Operation (Refer to Reference Value Setting Program) When the power is turned on, execution of the reference value setting program is automatically started. This program is executed in an environment where no human is present in the irradiation area A. The A / D converter 6 which takes in the received light signal V _L via the amplifier 5 receives the first pulse, the second pulse ... The nth pulse of the incoming light reception signal V _L based on the command from the CPU 8. The second pulse (however,
In this example, the maximum level value V _LMAX of n = 4) is converted into digital values D ₁ , D ₂ , ... D _n and sent to the detection control circuit 7. When the maximum level value V _LMAX of the nth pulse is digitally converted, the CPU 8 of the detection control circuit 7 confirms that the infrared ray R has been projected n times, and the n digital data D ₁ ,
An average value No of D ₂ , ... D _n is calculated and stored in the data memory 10 with the average value No as a reference value, and threshold values σ _u and σ _d are provided above and below the determination value K. (No-σ _d
≦ K ≦ No + σ _u ) is set.

II Detection Operation (See Detection Program) When the reference value setting operation is completed, the detection program shown in FIG. 4 is started.

The A / D converter 6 converts the maximum level value V _LMAX of the pulse of the incoming light receiving signal V _L into a digital value as in the reference value setting operation, and the CPU 8 converts the n (n = 4) number of pulses. When the maximum level value is converted into a digital value, n (n =
Digital values D _11, D ₁₂ of 4), by averaging the · · · D _1n calculates the average received light amount N _1, determines whether the average received light amount N ₁ is outside criterion K. When it is within the criterion K, relay
On the condition that 13 is deenergized and the door open / close command signal Y is extinguished, the above average received light amount calculation operation is repeated.

When the average amount of received light N ₁ is outside the criterion K, it is determined whether the average amount of received light N ₁ is affected by the sunlight entering the detection area A or an instantaneous disturbance caused by flying objects. To confirm, the same detection routine as above is repeated. That is, the CPU 8 averages the digital values of the subsequent 2n (n = 4) pulses to calculate the average received light amount N ₂ . In this case, an abnormally large digital value or an abnormally small digital value is excluded as a result of disturbance or an AC component, and the remaining digital values are averaged. Then
It is again determined whether or not this average received light amount N ₂ is outside the determination standard K, and if it is still outside the determination standard K, in order to confirm whether or not it is affected by disturbance, the third time The detection routine is repeated, and the CPU 8 continues to 2n pieces (n = 4)
Average digital value N ₃
Is calculated. Also in this case, an abnormally large or small digital value is excluded as a result of disturbance or an AC component, and the remaining digital values are averaged. CPU8
Compares the average received light amount N ₃ with the average received light amount N ₂ obtained in the second detection routine, and if they match or are close to each other, it is determined that a human body has entered the detection area A. Then, the human body detection signal X is sent to the relay 13. As a result, the relay 13 is energized and the door opening / closing command signal Y is sent to the door opening / closing drive device 14 and at the same time the on-timer 12 is set. For safety reasons, the on-timer 12 is safe even if the human body detection signal X disappears. The relay 13 is energized by turning on for a set time. It should be noted that the time required for the detection routine is extremely minute, and when viewed from the required time, it can be considered that a person who is heading toward the automatic door is stationary.

In this embodiment, the presence of a human body in the detection area A is detected by comparing the average amount of light received by the light receiver 4 with the criterion K, which is the amount of light received by the light receiver 4 when there is no detection target. Therefore, when a person enters the detection area A or when a person leaves the detection area A, it can be instantly detected, and the threshold value σ
_The detection sensitivity can be increased by setting _u and σ _d small.

Further, the determination standard K does not change even if a person stops in the detection area A, so that so-called stillness detection can be surely performed.

Further, in the present embodiment, the amount of received light to be compared with the determination reference K is an average value obtained by dividing a plurality of received amounts of light by the number of times of received light, so that the influence of disturbance can be significantly reduced and the influence of disturbance can be reduced. The detection routine for confirming whether or not there is an abnormally large or extremely small amount of received light is excluded in the calculation of the average amount of received light. You can virtually eliminate it.

In the above description of the embodiment, when the human body is present in the detection area A, the average value of the amount of received light is increased from the criterion K. However, for example, in the case where a black child has entered the detection area A, etc. In some cases, the average value of the amount of received light may be lower than the criterion K. In the present embodiment, the human body can be reliably detected even in such a case.

Further, in this embodiment, when the environment of the detection area A is artificially changed, a new environment determination standard can be automatically obtained only by executing the reference value setting program.

Further, in the present embodiment, since 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, the amount of light received by the light receiver in the absence of the detection target in the detection area is fixed as a reference value, a determination standard is created from the reference value, and the amount of received light is compared with the determination standard. Therefore, not only when the human body passes through the detection area but also when the human body is stopped in the detection area,
This can be reliably detected. In addition, since the instantaneous disturbance such as a flying object is distinguished by the confirmation operation of performing the human body detection again by calculating the average received light amount, the accuracy of the human body detection is improved.

If the checking operation includes the operation of not including the abnormal light receiving amount and the operation of comparing the current average light receiving amount with the previous average light receiving amount, variations in the detection operation of the device are eliminated and the human body detection accuracy is further improved. improves.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 (a) is an output waveform diagram of the projector in the above embodiment.
FIG. 3B is an output waveform diagram of the photodetector in the above embodiment, FIG. 3 is a flow chart of the reference value setting program in the above embodiment, and FIG. 4 is a flow chart of the detection program in the above embodiment. 1 ... Emitter, 3 ... Oscillator, 4 ... Receiver, 6 ... A /
D converter, 7 ... Detection control circuit, 8 ... CPU, 10 ... Data memory, A ... Detection area.

Claims (2)

[Claims] 1. A light projector for projecting infrared rays in a pulse shape to define a human body detection irradiation area, and a light receiver for defining a detection area in the irradiation area and receiving reflected light from the detection area. A detection control device that controls the light projection and the light reception and determines the presence / absence of a human body by capturing the light reception amount, and the detection control device repeats the light projection a predetermined number of times, and the light reception amount of the predetermined number of times. Calculate the average amount of received light based on the above, and if this average amount of received light is outside the threshold value set in the initially set criteria, confirm that the average amount of received light is calculated again and compared with the threshold value. An operation for creating a human body detection signal through the operation is executed, and the initially determined determination standard is an average based on a predetermined number of light reception amounts of the light receiver in the absence of a detection target in the detection area. Is created by Human body detection device. 2. The checking operation includes an operation of calculating an average light receiving amount by not including an abnormal light receiving amount and an operation of comparing a current average light receiving amount with a previous average light receiving amount with respect to this average light receiving amount. The human body detection device according to claim 1, characterized in that: