JP2952115B2 - Object detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detecting apparatus, and more particularly, to projecting light onto an object such as a human body and detecting the presence or absence of the object by detecting the reflected light reflected by the projected light. It relates to a device for detecting.

[0002]

2. Description of the Related Art Conventionally, an object detecting apparatus for detecting an object by using reflection of infrared light has been widely used in various fields of consumer and industry.

In such an object detecting device, first, infrared light is projected from a light emitting element such as a light emitting diode. If there is any object such as a human body in the space where the infrared light is projected, the light projected from the light emitting element is reflected on the object. The presence or absence of an object is detected by detecting the reflected light with a light receiving element such as a photodiode. That is, when the light receiving element detects the reflected light, it is determined that an object is present, and when the reflected light is not detected, it is determined that the object is not present.

As a power source of such an object detection device,
Commercial power or batteries are used. When a battery is used as a power supply, it is common to use a battery having a long battery life such as a lithium battery and to suppress the consumption of the battery by intermittently emitting light from a light emitting element at a constant cycle. As a result, the battery life is made as long as possible and the trouble of replacing the battery is reduced.

[0005]

Incidentally, in the above object detecting device, infrared light generated by some external factor acts as a disturbance (hereinafter referred to as disturbance light), and accurate object detection may not be performed. .

The reason is that the light receiving element only outputs a detection signal when infrared light of a predetermined wavelength is received, and the received infrared light is reflected by the projected light from the light emitting element. This is because it does not have a function of determining whether the light is reflected light or disturbance light reflected on the object.

Therefore, when the wavelength of the disturbance light matches the wavelength of the projection light of the light emitting element, it can be determined whether an object actually exists or the disturbance light is generated. That is, accurate object detection cannot be performed.

Particularly, in the inverter fluorescent lamp, since the lighting frequency is set to 30 KHz or less or 45 KHz or more by inverter control, disturbance light is generated at the same cycle as the lighting frequency.

When a plurality of inverter fluorescent lamps are installed in close proximity to each other, a "beat" is generated due to a shift in the lighting frequency of each inverter fluorescent lamp, and disturbance light whose cycle changes at 1 KHz or less is generated.

[0010] The disturbance light from the inverter fluorescent lamp is
When it acts on the above-described object detection device as periodic pulse-like noise (hereinafter, referred to as periodic pulse-like noise), a malfunction may be caused.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an object detection method capable of accurately detecting an object even when disturbance light such as periodic pulse noise is generated. It is to provide a device.

[0012]

[0013]

The present invention solves the above problems.
In an object detection device that projects light from a light-emitting element and detects the object by detecting the reflected light reflected from the object by the light-receiving element, first, the light-emitting element is turned on for a short time. When the light receiving element does not receive the reflected light with respect to the light emission of the light emitting element, it is determined that the object does not exist, and when the reflected light is received by the light receiving element, the light emitting element is next emitted. When the light-receiving element receives the reflected light without interruption for the light emitted by the light-emitting element, it is determined that an object exists and the light-receiving element does not receive the reflected light or The point is that a control determination device that determines that an object does not exist when is interrupted is provided.

[0014]

[0015]

[0016]

By the action above means, first, the light-emitting element briefly emit light. When the light receiving element does not receive the reflected light of the projection light of the light emitting element, it is determined that the object does not exist. When the light receiving element receives light, the light emitting element emits light for a long time. Then, it is determined that an object is present only when the light receiving element can receive the reflected light of the projection light of the light emitting element without interruption.

That is, first, the light emitting element is caused to emit light for a short time to roughly determine the presence of an object. If the result of the rough determination indicates that the object is present, then the light emitting element is caused to emit light for a long time. To accurately determine the presence of the object.

Therefore, when it is roughly determined that no object is present, the light emitting element is not allowed to emit light for a long time, so that the power consumption of the object detection device can be reduced accordingly.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the object detecting apparatus of the present invention is embodied in an automatic washing apparatus for a flush toilet for men (hereinafter referred to as morning glory) will be described with reference to the drawings.

FIGS. 2 and 3 show the mounting state of the morning glory 1 of this embodiment. The morning glory 1 is attached to the front side of the wall surface 2 of the washroom, and an electromagnetic on-off valve 4 is connected to a water supply pipe 3 connected to the morning glory 1. When the electromagnetic on-off valve 4 is opened, washing water is supplied from the water supply pipe 3 to the morning glory 1. Conversely, when the electromagnetic on-off valve 4 is closed, the morning glory 1
The supply of the washing water to the is shut off.

The control box 5 has a wall 2 slightly above the morning glory 1.
Of the control box 5 is attached to the wall 2
It is exposed to. A human detection sensor 6 including a light emitting element 6a and a light receiving element 6b is provided on the front plate 5a.
A controller 7 and a lithium battery 8 are provided therein.

The light emitting element 6a is composed of a light emitting diode and emits infrared light having a predetermined wavelength. The light receiving element 6b is composed of a photodiode or a phototransistor, and outputs a detection signal only when infrared light having the same wavelength as the light projected from the light emitting element 6a is received.

FIG. 1 shows an electric block circuit of the automatic cleaning apparatus of this embodiment. The lithium battery 8 is connected to the controller 7
The power supply is supplied to the constant voltage circuit 20 and the valve drive circuit 21 therein.

The constant voltage circuit 20 is constituted by a three-terminal regulator, and includes a microcomputer (hereinafter abbreviated as a microcomputer) 22 in the controller 7, a light emission drive circuit 23,
A stable DC voltage is supplied to each of the switching circuits 24.

The microcomputer 22 has a central processing unit (CP)
U), a read-only memory (ROM) storing a control program, a readable and writable memory (RAM) for temporarily storing a result of a human detection operation described later, an input / output interface, and the like.

Then, the microcomputer 22 outputs a command signal S to the switching circuit 24 for a fixed time at 0.7 second intervals. The microcomputer 22 generates a pulse wave having a frequency of 38 KHz and a duty of 50% (pulse width of about 26 μsec).
Is output to the light emission drive circuit 23.

The light emission drive circuit 23 causes the light emitting element 6a to emit light based on a light emission command signal F from the microcomputer 22.
That is, the light emission drive circuit 23 causes the light emitting element 6a to emit light once each time one pulse of the light emission command signal F is input.

Therefore, if the microcomputer 22 continuously outputs the light emission command signal F for 200 μsec, the light emission drive circuit 23 causes the light emitting element 6a to emit light eight times. When the microcomputer 22 continuously outputs the light emission command signal F for 10 msec, the light emission drive circuit 23 causes the light emitting element 6a to emit light 380 times.

The switching circuit 24 is on / off controlled based on a command signal S from the microcomputer 22. The switching circuit 24 is turned on when the constant voltage circuit 20 is turned on.
Is supplied to the light receiving circuit 25, and the power supply to the light receiving circuit 25 is cut off when the power is off. Light receiving circuit 25
Becomes operable only when power is supplied from the switching circuit 24.

Incidentally, the command signal S from the microcomputer 22 is set to 0.1.
Since the signal is output for a fixed time at intervals of 7 seconds, the switching circuit 24 also outputs the light receiving circuit 2 for a fixed time at intervals of 0.7 seconds.
5 is powered. Therefore, the light receiving circuit 25 is turned on for a fixed time at 0.7-second intervals, and becomes operable.

The light receiving circuit 25 amplifies the detection signal of the light receiving element 6b, integrates the signal, shapes the waveform, and generates a light receiving signal R. That is, since the light emitting element 6a emits light in accordance with the pulse of the light emission command signal F, the light emission is not continuous, but blinks using the frequency (38 KHz) of the light emission command signal F as the lighting frequency. Therefore, the detection signal of the light receiving element 6b is not continuous, but corresponds to the frequency of the light emission command signal F. Therefore, by integrating the detection signal of the light receiving element 6b in the light receiving circuit 25 and then shaping the waveform, a continuous light receiving signal R is obtained.

Then, the light receiving circuit 25 outputs the generated light receiving signal R to the microcomputer 22. The light receiving element 6b is
The detection signal is output in the same manner whether the reflected light of the light projected from the light emitting element 6a is received or the disturbance light having the same wavelength as the light projected by the light emitting element 6a is received.

Therefore, the light receiving circuit 25 includes the light emitting element 6a
The light receiving signal R is output in the same manner regardless of whether the reflected light of the projected light is received or the disturbance light having the same wavelength as the projected light of the light emitting element 6a is received.

The valve drive circuit 21 opens and closes the solenoid on-off valve 4 composed of a self-holding solenoid valve based on a command signal from the microcomputer 22. That is, each time the valve drive circuit 21 outputs a pulse-like timing signal, the electromagnetic on-off valve 4
The open / close state is switched, and when the timing signal is not output, the previous open / close state is held as it is.

Next, an operation for detecting whether or not a person is standing in front of the morning glory 1 in the embodiment configured as described above (hereinafter, referred to as a person detection operation) will be described with reference to a flowchart shown in FIG. I do.

First, in step (hereinafter referred to as S) 1, the microcomputer 22 outputs a command signal S to the switching circuit 24. Therefore, the switching circuit 24 turns on and supplies power to the light receiving circuit 25. Then, the light receiving circuit 25 is turned on and becomes operable. Then, the process proceeds to S2.

In S2, the microcomputer 22 continues to output the light emission command signal F to the light emission drive circuit 23 for 200 μsec. Based on the light emission command signal F, the light emission drive circuit 2
3 causes the light emitting element 6a to emit light eight times. Then, the process proceeds to S3.

In S3, the microcomputer 22 determines whether or not the light receiving signal R is output from the light receiving circuit 25. That is, when a person is standing in front of the morning glory 1, the projection light from the light emitting element 6a reflects on the person. Then, the light receiving element 6b detects the reflected light and outputs a detection signal. The light receiving circuit 25 detects the light receiving signal R from the detection signal.
Is generated and output.

When no person stands in front of the morning glory 1, the light projected from the light emitting element 6a is not reflected, and the light receiving element 6a is not reflected.
b does not output a detection signal because reflected light cannot be detected.
Therefore, the light receiving circuit 25 does not output the light receiving signal R.

If the light receiving signal R is output, S
To S4, and if not output, to S5.
In the microcomputer 22, the light emission drive circuit 23
During c, the light emission command signal F is continuously output. Based on the light emission command signal F, the light emission drive circuit 23 causes the light emitting element 6a to emit light 380 times. Then, the process proceeds to S6.

In S6, the microcomputer 22 determines whether the light receiving signal R is output from the light receiving circuit 25 and whether the light receiving signal R is not interrupted.
That is, similarly to S3, when a person stands before the morning glory 1, the light receiving circuit 25 outputs the light receiving signal R. When no person stands before morning glory 1, light receiving circuit 25 does not output light receiving signal R.

By the way, actually, no person stands in front of the morning glory 1 and the disturbance light generated for some reason
Even when b receives light, the light receiving signal R is output.

However, it is rare that disturbance light is generated continuously for as long as 10 msec. In particular, the aforementioned periodic pulse-like noise does not continuously occur for as long as 10 msec.

Therefore, when the light receiving signal R output from the light receiving circuit 25 is due to disturbance light, particularly periodic pulse noise, the light receiving signal R does not continue as shown in FIG. There is always one interruption during 10 msec when F is output.

On the other hand, when the light receiving signal R output from the light receiving circuit 25 is due to the reflected light from a person, as shown in FIG.
There is no interruption during the 10 msec when is output.

If the output light-receiving signal R is not interrupted, it is determined that the light-receiving signal R is due to light reflected from a person, and the flow shifts to S7. If the light reception signal R is not output or is interrupted, the light reception signal R output in S3 is determined to be due to disturbance light, and the process proceeds to S5. It is determined that a person is standing and “human detection” is determined, and the determination result is stored in the RAM.
To memorize. Then, control goes to a step S8.

On the other hand, in S5, the microcomputer 22 determines that a person is not standing in front of the morning glory 1 and determines "non-detection", and stores the determination result in the RAM. Then, control goes to a step S8.

In S8, the microcomputer 22 stops outputting the command signal S to the switching circuit 24. Therefore, the switching circuit 24 is turned off, and the power supply to the light receiving circuit 25 is cut off. Then, the power of the light receiving circuit 25 is turned off and the operation stops. Then, the process returns to S1.

As described above, in this embodiment, the light-emitting element 6a emits light intermittently at a constant period of 0.7 seconds. In one cycle, first, the light emitting element 6a emits light eight consecutive times for about 197 μsec, and if the light receiving element 6b receives light, then the light emitting element 6a is turned off.
Emit light for 80 msec for 10 msec.

As a result, the light emitting element 6a emits light 1
Only when the light receiving element 6b receives light without interruption for 0 msec, it is determined that a person is standing in front of the morning glory 1 (that is, "human detection").

On the other hand, when the light receiving element 6b does not receive light when the light emitting element 6a first emits light eight times in succession,
It is determined that no person is standing in front of morning glory 1 (that is, “non-human detection”).

Next, when the light emitting element 6a emits light 380 times continuously, the light receiving element 6b does not receive light or the light reception is interrupted, no person stands in front of the morning glory 1. (That is, “human non-detection”).

That is, in this embodiment, first, the light emitting element 6a is made to emit light for a short time (about 197 μsec ≒ 200 μsec), and if the light receiving element 6b receives light, then, the light emitting element 6a is made to emit light for a long time (10 msec = 200 μsec). (50 times as large as that of the above), and it is confirmed again whether or not the previous light reception was caused by disturbance light.

Therefore, the presence of a person can be accurately detected without being affected by disturbance light such as periodic pulse noise. In addition, if the light-receiving element 6b does not receive light when the light-emitting element 6a emits light for a short time, it is determined as "non-human detection" by itself and the human detection operation routine is terminated, and the light-emitting element 6a emits light for a long time Since this is not performed, the power consumption of the controller 7 is reduced accordingly.

If the power consumption of the controller 7 is reduced, the consumption of the lithium battery 8 can be suppressed, so that the life of the lithium battery 8 is prolonged and the trouble of replacing the battery can be reduced.

Since the light receiving circuit 25 becomes operable every 0.7 seconds, the routine of the human detecting operation is performed at 0.7 seconds.
Repeated every second interval. That is, the determination result of “human detection” or “non-human detection” is stored in the RAM in the microcomputer 22 for each routine.

When the determination result of "human detection" is repeated twice after the determination result of "human non-detection", the microcomputer 22 tries to add a small person to the person standing in front of the morning glory 1. Is determined.

This is because even if a person crosses the front of the morning glory 1, a determination result of "human detection" may occur only once. That is, if the determination result of “human detection” is repeated twice, the number of persons standing in front of morning glory 1 is 0.
This means that the user has stopped for more than 7 seconds, which means that he is not just crossing the front of the morning glory 1, but is trying to add a small amount of work.

Then, the microcomputer 22 controls the valve drive circuit 21 to open the electromagnetic opening / closing valve 4 for a fixed time to supply a fixed amount of washing water to the morning glory 1 from the water supply pipe 3.
Wash morning glory 1. As a result, it is possible to comfortably add small items and to make the morning glory 1 difficult to stain.

Subsequently, if the determination result of “human detection” is followed by the determination result of “non-human detection” twice, the microcomputer 22 determines that the person who has completed the small use has left before the morning glory 1. I do.

This is because even if the body of the person shakes during the small use, a determination result of "non-detection of the person" may occur only once. In other words, if the result of the determination of “people not detected” is repeated twice, there is no person for more than 0.7 seconds in front of morning glory 1, and it can be surely confirmed that the person who has completed the small work has left. That is.

Then, the microcomputer 22 controls the valve drive circuit 21 to open the electromagnetic opening / closing valve 4 for a fixed time to supply a fixed amount of washing water from the water supply pipe 3 to the morning glory 1.
Wash morning glory 1.

As described above, in the apparatus for automatically cleaning morning glory 1, when a person who wants to add a small person stands in front of morning glory 1,
After cleaning (pre-cleaning) and adding small items
After that, the morning glory 1 is washed again (post-washing process) when the user leaves from the front.

Note that the present invention is not limited to the above-described embodiment, and may be carried out with the following changes. 1) Replace the lithium battery 8 with a power supply and supply power from a commercial power supply. In this case, since it is not necessary to pay attention to the consumption of the battery, the light emitting element 6a does not need to emit light eight times first, and the light emitting element 6a may emit light 380 times from the beginning.

That is, it is only necessary to make the light emitting element 6a emit light 380 times at 0.7 second intervals and determine whether the light receiving element 6b receives light without interruption. 2) The number of times of light emission of the light emitting element 6a in one cycle is 8 and 3
Instead of 80 times, the number is set to an appropriate number.

3) The interval at which the command signal S is output from the microcomputer 22 is set to an appropriate time instead of 0.7 seconds.
That is, the light emission period of the light emitting element 6a is set appropriately. 4) The light emission command signal F is not a pulse wave having a frequency of 38 KHz and a duty of 50%, but a pulse wave having an appropriate duty different from the lighting frequency of the inverter fluorescent lamp. Further, the light emission command signal F is not a pulse wave but a signal in which a constant voltage is continuous.

5) The pre-cleaning process is performed even if the determination result of "human detection" is found only once after the determination result of "human detection". The post-cleaning process is performed even when the determination result of “human detection” is once after the determination result of “human detection”.

6) Use visible light or ultraviolet light instead of infrared light. That is, the light emitting element 6a projects visible light or ultraviolet light instead of infrared light, and the light receiving element 6b receives the projected light and outputs a detection signal.

7) Use ultrasonic waves instead of light. That is, the light emitting element 6a is replaced with an ultrasonic speaker, and the light receiving element 6b is replaced with an ultrasonic microphone. Further, the circuit configurations of the light receiving circuit 25 and the light emitting circuit 23 are appropriately changed. Then, a sound wave reflected from the ultrasonic speaker from the ultrasonic speaker hits the object is detected by the ultrasonic microphone.

8) The present invention is embodied not only in the morning glory 1 but also in an automatic cleaning device for various sanitary appliances such as a wash basin. 9) Not only an automatic cleaning device for sanitary appliances but also other object detection devices such as automatic doors and FA devices.

10) The above-mentioned items 1) to 9) are appropriately combined.

[0072]

As described in detail above, according to the present invention , an object can be accurately detected even when disturbance such as periodic pulse noise occurs.

[Brief description of the drawings]

FIG. 1 is an electric block circuit diagram of an automatic cleaning device according to one embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing an attached state of a men's flush urinal (morning glory) of one embodiment.

FIG. 3 is a front view of the men's flush urinal (morning glory) shown in FIG. 2;

FIG. 4 is a flowchart illustrating a human detection operation according to one embodiment.

FIG. 5 is a time chart showing a light emission command signal F and a light reception signal R when disturbance light occurs in one embodiment.

FIG. 6 is a time chart showing a light emission command signal F and a light reception signal R when disturbance light does not occur in one embodiment.

[Explanation of symbols]

6a: light-emitting element, 6b: light-receiving element, 22: microcomputer as control determination device

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01V 9/04

Claims (1)

(57) [Claims] A light is projected from a light emitting element (6a), and reflected light reflected by the projected light hitting an object is received by a light receiving element (6a).
In the object detection device configured to detect an object by performing the detection in step b), first, the light emitting element (6a) emits light for a short time, and the reflected light is emitted in response to the light emission of the light emitting element (6a). When the light receiving element (6b) does not receive the light, it is determined that the object is not present. When the reflected light is received by the light receiving element (6b), the light emitting element (6a) is caused to emit light for a long time. When the reflected light is received without interruption by the light receiving element (6b) with respect to the light emission of the light emitting element (6a), it is determined that an object is present, and the reflected light is not received by the light receiving element (6b). The control determining device (2) that determines that no object exists when
An object detection device characterized by including (2).