JPH06207987A - Object detector - Google Patents

Abstract

PURPOSE:To exactly detect an object even when infrared light generated by a certain cause affects as a disturbance to an object detector using infrared light. CONSTITUTION:A microcomputer 22 illuminates at first a luminescent element 6a based on predetermined illumination code A. After a certain time, the microcomputer 22 illuminates the luminescent element 6a based on the predetermined illumination code B. Only when both reflection light of the luminescent element 6a by the two kinds of illumination codes A, B is received by a light receiving element 6b and a light receiving signal R is output from the light receiving circuit 24, the microcomputer 22 judges existence of an object (man). And the microcomputer 22 judges the non-existence of an object when both or one of the reflection lights of the luminescent element 6a by the two kinds of illumination codes A, B is not received by the light receiving element 6b and light receiving signal R is not output from the light receiving circuit 24.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, an object detecting device for detecting an object by utilizing 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. When an object such as a human body exists in the space where the infrared light is projected, the projection light from the light emitting element hits the object and is reflected. 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 the object exists, and when the reflected light is not detected, it is determined that the object does not exist.

As a power source for such an object detecting device,
Commercial power or batteries are used. When a battery is used as a power source, it is general to use a battery having a long battery life, such as a lithium battery, and intermittently cause a light emitting element to emit light at a constant cycle to suppress battery consumption. As a result, the battery life is made as long as possible to reduce the labor for battery replacement.

[0005]

By the way, in the above-mentioned object detecting device, infrared light generated by some external cause may act as a disturbance (hereinafter referred to as disturbance light), and accurate object detection may not be possible. .

This is because the light receiving element only outputs a detection signal when it receives infrared light of a predetermined wavelength, and the received infrared light is the projected light from the light emitting element. This is because it does not have a function of discriminating whether the light is reflected light reflected from an object or ambient light.

Therefore, when the wavelength of the ambient light coincides with the wavelength of the projected light of the light emitting element, particularly in the case of periodic pulsed noise, whether the ambient light is present or whether the ambient light is present. It is not possible to discriminate whether or not it is occurring, and accurate object detection is not possible.

The present invention has been made to solve the above problems, and an object thereof is to detect an object which can accurately detect an object even when disturbance light such as periodic pulse noise is generated. To provide a device.

[0009]

In order to solve the above problems, the present invention detects an object by projecting light from a light emitting element and detecting reflected light reflected by the projected light upon an object by a light receiving element. In the object detecting device, the second code for outputting the first code signal for causing the light emitting element to emit light in a fixed pattern and for causing the light emitting element to emit light in a pattern different from the previous fixed pattern. Code generating means for outputting a signal, and first of all, the light emitting element is caused to emit light in a fixed pattern based on the first code signal, and then, after a predetermined time has elapsed, the light emitting element is turned on based on the second code signal. The light-emitting element emits light in a pattern different from the above-mentioned fixed pattern, and the light-receiving element receives the reflected light of both of the light emission of the light-emitting element by the first and second code signals. It is determined that the object is present only in the case, and if the light receiving element does not receive the reflected light of both or either one of them, the control determining means for determining that the object does not exist is provided. Use as a summary.

[0010]

The control determination device first causes the light emitting element to emit light in a fixed pattern based on the first code signal.
Next, after a certain period of time has passed, the control determination device causes the light emitting element to emit light in a pattern different from the pattern of the first code signal based on the second code signal. Then, the control determination device determines that the object is present only when the light receiving element receives the reflected light of both of the light emission of the light emitting element by the first and second code signals.

By the way, it is very rare that the ambient light coincides with either the first code signal or the second code signal. Furthermore, it can be said that ambient light rarely matches both the first and second code signals. Therefore, the ambient light is not mistaken as the reflected light of the projection light from the light emitting element and is not judged to be present. Therefore, the object can be accurately detected without being affected by the ambient light.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the object detecting device of the present invention is embodied in an automatic cleaning device for a men's flush urinal (hereinafter referred to as a morning glory) will be described with reference to the drawings.

2 and 3 show the state of attachment 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 the water supply pipe 3 connected to the morning glory 1 is connected with an electromagnetic opening / closing valve 4. When the electromagnetic opening / closing valve 4 is opened, washing water is supplied from the water supply pipe 3 to the morning glory 1. On the other hand, when the electromagnetic on-off valve 4 is closed, the water supply pipe 3 causes
The supply of washing water to the machine is cut off.

The control box 5 is a wall surface 2 slightly above the morning glory 1.
Is attached to the back side of the control box 5, and the surface plate 5a of the control box 5 is attached to the wall surface 2
Is exposed to. The front plate 5a is provided with a human detection sensor 6 including a light emitting element 6a and a light receiving element 6b.
A controller 7 and a lithium battery 8 are provided inside.

The light emitting element 6a is composed of a light emitting diode and projects infrared light having a preset wavelength. The light receiving element 6b is composed of a photodiode or a phototransistor, and outputs a detection signal only when it receives infrared light having the same wavelength as the projected light of the light emitting element 6a.

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

The constant voltage circuit 20 is composed of 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 light receiving circuits 24.

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

Then, the microcomputer 22 performs a timer operation. Further, the microcomputer 22 has a duty of 5 at a predetermined frequency.
The light emission drive circuit 2 outputs the light emission command signal F which is a 0% pulse wave.
Output to 3.

The light emission drive circuit 23 causes the light emitting element 6a to emit light based on the 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, from the microcomputer 22 for a fixed time,
When the light emission command signal F is continuously output, the light emission drive circuit 23
Causes the light emitting element 6a to emit light a certain number of times. Light receiving circuit 24
Amplifies the detection signal of the light receiving element 6b, integrates it, and then shapes the waveform to generate a light receiving signal R, which is output to the microcomputer 22.

That is, when a person stands in front of the morning glory 1, the projection light from the light emitting element 6a is reflected by the person. Then, the light receiving element 6b detects the reflected light and outputs a detection signal, and the light receiving circuit 24 amplifies and outputs the detection signal. On the other hand, when no person is standing in front of the morning glory 1, the projection light from the light emitting element 6a is not reflected. Then,
Since the light receiving element 6b cannot detect the reflected light, it does not output the detection signal and the light receiving circuit 24 does not output the light receiving signal R.

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 flashes with the frequency 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, the detection signal of the light receiving element 6b is integrated in the light receiving circuit 24 and then waveform shaped to obtain a continuous light receiving signal R.

Further, the light receiving element 6b outputs the detection signal in the same manner whether it receives the reflected light of the projection light of the light emitting element 6a or the disturbance light of the same wavelength as the projection light of the light emitting element 6a. To do. Therefore, the light receiving circuit 24 outputs the light reception signal R in the same manner whether it receives the reflected light of the projection light of the light emitting element 6a or the disturbance light of the same wavelength as the projection light of the light emitting element 6a.

Here, the light emission command signal F from the microcomputer 22 is output according to two preset light emission codes A and B, as shown in FIG. That is, the state in which the light emission command signal F is output for C μsec and then the output is stopped for C μsec is designated as code “1”. Also,
A state in which the output of the light emission command signal F is stopped only for Dμsec (= 2Cμsec) is defined as code “0”.

A combination of the codes "0" and "1" in the order of "1011001" is defined as a light emitting code A, and a combination of the codes in the order of "1101010" is defined as a light emitting code B.

Therefore, in the light emission code A, the light emission command signal F is Cμsec output → Dμsec output stop → Cμse
c Output → Cμsec Output stop → Cμsec output → Eμsec
(= 5 Cμsec) Output stopped → Cμsec output → Cμsec output stopped in this order.

On the other hand, in the light emission code B, the light emission command signal F is output in the order of Cμsec output → Cμsec output stop → Cμsec output → Dμsec output stop → Cμsec output → Dμsec output stop → Cμsec output → Dμsec output stop. .

Therefore, the light emitting element 6a emits light based on the light emission command signal F according to the light emitting code A (or B), and the reflected light of the projection light of the light emitting element 6a is received by the light receiving element 6a.
When the light is correctly received, the light reception signal R is output according to the light emission code A (or B).

The valve drive circuit 21 opens and closes the electromagnetic on-off valve 4 consisting 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 pulsed timing signal, the electromagnetic on-off valve 4
The open / closed state is switched, and when the timing signal is not output, the previous open / closed state is maintained as it is.

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

First, in step (hereinafter referred to as S) 1, the microcomputer 22 outputs a light emission command signal F to the light emission drive circuit 23 according to the light emission code A. Based on the light emission command signal F according to the light emission code A, the light emission drive circuit 2
3 makes the light emitting element 6a emit light.

That is, based on the light emitting code A, the light emitting element 6a emits light for a certain number of times in Cμsec → stops emitting light for a certain number of Dμsec → emits light for a certain number of times in Cμsec → stops emitting light for a certain number of Cμsec → emits a certain number of times in Cμsec → Eμsec. The light emission is stopped for a certain period of time, the light is emitted for a certain number of times in Cμsec, and then the light emission is stopped for only Cμsec.

Then, the process proceeds to S2. In S2,
The microcomputer 22 waits until a fixed time elapses, and when the fixed time elapses, proceeds to S3.

In S3, the microcomputer 22 outputs a light emission command signal F to the light emission drive circuit 23 according to the light emission code B. Based on the light emission command signal F according to the light emission code B, the light emission drive circuit 23 causes the light emitting element 6a to emit light.

That is, the light emitting element 6a emits light for a certain number of times in Cμsec → stops emitting light for Cμsec → emits light for a certain number of times in Cμsec → stops emitting light for only Dμsec → emits light for a certain number of times in Cμsec → Dμsec. The light emission is stopped for a certain period of time, the light is emitted for a certain number of times in Cμsec, and then the light emission is stopped for only Dμsec.

Then, the process proceeds to S4. In S4,
The microcomputer 22 uses the light emitting element 6a in S1 and S3.
For the light emission based on the light emission codes A and B of
It is determined whether or not both of the light-receiving elements b correctly receive light and the light-receiving circuit 24 outputs the light-receiving signal R according to the light-emitting codes A and B.

That is, in S1, when a person stands in front of the morning glory 1 when the light emitting element 6a is caused to emit light by the light emission command signal F of the light emitting code A, the projected light from the light emitting element 6a hits the person. reflect. Then, the light receiving element 6b detects the reflected light and outputs a detection signal, and the light receiving circuit 24 outputs a light reception signal R obtained by amplifying the detection signal.

At this time, no ambient light is generated, and the light emitting element 6
When the light receiving element 6b accurately receives the reflected light of the projected light of a, the light receiving signal R is output according to the light emitting code A.

Then, after a lapse of a predetermined time in S2, S
3, when a person stands in front of the morning glory 1 when the light emitting element 6a is caused to emit light by the light emission command signal F of the light emitting code B, the projection light from the light emitting element 6a is reflected by the person. Then, the light receiving element 6b detects the reflected light and outputs a detection signal, and the light receiving circuit 24 outputs a light reception signal R obtained by amplifying the detection signal.

At this time, no ambient light is generated and the light emitting element 6
When the light receiving element 6b correctly receives the reflected light of the projected light of a, the light receiving signal R is output according to the light emitting code B.

Therefore, when the light receiving circuit 24 outputs the light receiving signal R according to the light emitting codes A and B, the morning glory 1
You can see that a person has been standing in front of for a certain time or more. On the other hand, if the light receiving circuit 24 does not output the light receiving signal R according to the light emitting codes A and B, it can be seen that no person appears in front of the morning glory 1 for a certain period of time or longer.

When the light receiving signal R according to the light emitting code A is output, but the light receiving signal R according to the light emitting code B is not output, a person simply crosses the front of the morning glory 1. I understand.

Similarly, the light reception signal R according to the light emission code A
Is output, but when the light reception signal R according to the light emission code B is not output, it is understood that the person has just appeared in front of the morning glory 1.

If the light receiving circuit 24 outputs the light receiving signal R according to the light emitting codes A and B, the process proceeds to S5, and the light receiving signal R according to at least one of the light emitting codes A and B is output. If not, the process proceeds to S6.

In S5, the microcomputer 22 determines that a person is standing in front of the morning glory 1 as "person detection", and stores the determination result in the RAM. Then, the process proceeds to S7. On the other hand, in S6, the microcomputer 22 determines that "a person is not detected" because no person is standing in front of the morning glory 1 and stores the determination result in the RAM. Then, the process proceeds to S7.

In S7, the microcomputer 22 waits until a fixed time has elapsed, and returns to S1 after the fixed time has elapsed. As described above, in this embodiment, first, the light emitting element 6a is caused to emit light based on the light emitting code A. And after a certain time,
Next, the light emitting element 6a is caused to emit light based on the light emitting code B.

In response to the light emission by these two types of light emitting codes A and B, the microcomputer 22 outputs a light receiving signal R according to the light emitting codes A and B, and a person stands in front of the morning glory 1. (That is, “human detection”).

On the other hand, when the microcomputer 22 does not output the light reception signal R according to at least one of the light emission codes A and B for the light emission by the two types of light emission codes A and B, the morning glory 1 It is determined that no person is standing in front (that is, "non-detection").

By the way, when an inverter fluorescent lamp is used as illumination for the place where the automatic washing device of the morning glory 1 is installed, periodic pulse noise may occur as described above. However, the periodic pulse noise rarely matches with either of the light emitting codes A and B, and it is unlikely that the periodic pulse noise with both of the light emitting codes A and B matches.

Further, it can be said that the disturbance light other than the periodic pulse noise is unlikely to coincide with both emission codes A and B. As described above, in the present embodiment, the "human detection" is determined only when the light receiving signal R according to both the light emitting codes A and B is output. Therefore, the ambient light such as the periodic pulse noise is not mistaken as the reflected light of the projection light from the light emitting element 6a and is not determined as "human detection".

Therefore, in this embodiment, even if the disturbance light such as the periodic pulse noise is generated, the person standing in front of the morning glory 1 can be accurately detected without being affected by the disturbance light. .

Then, if the judgment result "human detection" follows the judgment result "human non-detection", the microcomputer 22
Performs a pre-cleaning process. That is, the microcomputer 22 controls the valve drive circuit 21 to open the electromagnetic opening / closing valve 4 for a certain period of time to supply a certain amount of washing water from the water supply pipe 3 to the morning glory 1 to wash the morning glory 1. As a result, the small amount can be comfortably added and the morning glory 1 is less likely to get dirty.

Next, if the result of the judgment "human detection" is followed by the result of the judgment "human non-detection", the microcomputer 22
Judges that the person who has finished adding small amounts has left from the morning glory 1 and performs post-cleaning processing.

That is, the microcomputer 22 uses the valve drive circuit 2
By controlling 1, the electromagnetic opening / closing valve 4 is opened for a certain period of time to supply a certain amount of cleaning water from the water supply pipe 3 to the morning glory 1 to clean the morning glory 1.

As described above, in the automatic washing device for the morning glory 1, when a person who intends to take a small dose stands in front of the morning glory 1, the morning glory 1
The morning glory 1 is the person who has finished cleaning after washing (pre-cleaning)
When the person leaves the room in front of, the morning glory 1 is washed again (post-washing process).

The present invention is not limited to the above embodiment, and the following items may be changed and implemented. 1) Each code “0” or “1” is set appropriately.
That is, a state in which the light emission command signal F is output for an appropriate time and then the output is stopped for the same time is referred to as a code “1”. Further, the state in which the output of the light emission command signal F is stopped for a time twice as long as the appropriate time in the code "1" is defined as a code "0".

2) Change the light emitting codes A and B to "0" for each code.
An appropriate number and an appropriate combination of “1” are set. 3) Change the light emitting code to A. Instead of the two types of B, three or more types are prepared and are carried out in the same manner as the above embodiment.

4) The frequency of the light emission command signal F is set to an appropriate frequency in a range different from the lighting frequency of the inverter fluorescent lamp. Further, the frequencies of the light emission command signals F in the respective light emission codes A and B are made different. For example, the frequency of the light emission command signal F in the light emission code A is set to XKHZ, and the frequency of the light emission command signal F in the light emission code B is set to YKHZ. In this case, accurate human detection operation can be performed even in a place where a plurality of inverter fluorescent lamps having different lighting frequencies are installed close to each other.

5) Instead of causing the microcomputer 22 to perform the timer operation, a timer circuit is provided as a peripheral circuit of the microcomputer 22, and the timer circuit is caused to perform the timer operation. 6) The pre-cleaning process is performed when the determination result of "human detection" follows the determination result of "human non-detection" twice in a row. If the determination result of "human detection" is followed by the determination result of "human non-detection" twice, the post-cleaning process is performed. In this case, even if a person simply crosses the front of the morning glory 1 or if the person's body shakes during small use, the person detection operation can be performed more reliably, and the pre-cleaning process and the post-cleaning process are erroneous. To stop doing it.

7) The light emission command signal F is not a pulse wave having a duty of 50% but a pulse wave having an arbitrary duty. 8) Replace the lithium battery 8 with a DC power supply device and supply power from a commercial power supply.

9) Use visible light or ultraviolet light instead of infrared light. That is, the light emitting element 6a projects not visible light but visible light or ultraviolet light, and the light receiving element 6b receives the projected light and outputs a detection signal.

10) Use ultrasonic waves instead of light. That is, the light emitting element 6a is replaced with an ultrasonic speaker,
The light receiving element 6b is replaced with an ultrasonic microphone.
Further, the circuit configurations of the light receiving circuit 24 and the light emitting circuit 23 are appropriately changed. Then, the sound wave reflected by the ultrasonic wave from the ultrasonic sounder upon hitting the object is detected by the ultrasonic sound microphone.

11) Not only the morning glory 1 but also an automatic cleaning device for various sanitary appliances such as a wash basin. 12) Not only the automatic cleaning device for sanitary equipment, but also other object detection devices such as automatic doors and FA devices.

13) The above 1) to 12) are appropriately combined and carried out.

[0066]

As described in detail above, according to the present invention, there is an excellent effect that an object can be accurately detected even when disturbance light such as periodic pulse noise is generated.

[Brief description of drawings]

FIG. 1 is an electric block circuit diagram of an embodiment in which the present invention is embodied in an automatic washing device for a flush urinal for men (morning glory).

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

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

FIG. 4 is a time chart showing emission codes A and B.

FIG. 5 is a flowchart showing a person detecting operation in one embodiment.

[Explanation of symbols]

6a ... Light emitting element, 6b ... Light receiving element, 22 ... Microcomputer as control determining means, light emitting code A ... First code signal, light emitting code B ... Second code signal

Claims (1)

[Claims] 1. A light receiving element (6) that emits light from a light emitting element (6a), and reflects the reflected light reflected by the projected light upon an object.
In an object detection device configured to detect an object by detecting in step b), the first light emitting element (6a) outputs a first code signal for causing the light emitting element (6a) to emit light in a fixed pattern, and the light emitting element (6a)
Code generating means (2) for outputting a second code signal for emitting light in a pattern different from the above predetermined pattern.
2), and first, based on the first code signal, the light emitting element (6
a) is made to emit light in a fixed pattern, and then, after a fixed time has elapsed, the light emitting element (6a) is made to emit light in a pattern different from the aforementioned fixed pattern based on the second code signal. With respect to the light emission of the light emitting element (6a) by the code signal 2 of 2, it is determined that the object exists only when the light receiving element (6b) receives both of the reflected light, and either or both of them are determined. An object detection device comprising a control determination means (22) for determining that an object does not exist when the light receiving element (6b) does not receive the reflected light.