JP2986662B2 - 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, especially in the case of periodic pulse noise, whether an object actually exists or whether the disturbance light is present. In other words, it cannot be determined whether or not an error has occurred, and accurate object detection cannot be performed.

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.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention detects an object by projecting light from a light-emitting element and detecting, by a light-receiving element, light reflected by the projected light hitting the object. In the object detecting device, a first code signal for causing the light emitting element to emit light in a predetermined pattern is output, and a second code for causing the light emitting element to emit light in a pattern different from the predetermined pattern is used. Code generating means for outputting a signal; first, the light emitting element is caused to emit light in a fixed pattern based on the first code signal, and then, after a certain period of time, the light emitting element is controlled based on the second code signal. The light-emitting element is caused to emit light in a pattern different from the predetermined pattern, and the light-receiving element receives both reflected light in response to the light emission of the light-emitting element by the first and second code signals. Only when it is determined that the object is present, and when the light receiving element does not receive the reflected light of both or one of them, the control determining means for determining that the object is not present is provided. Make a summary.

[0010]

The control determining device first causes the light emitting element to emit light in a fixed pattern based on the first code signal.
Next, after a lapse of a predetermined time, the control determination device causes the light emitting element to emit light in a pattern different from the pattern based on 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 both reflected lights with respect to the light emission of the light emitting element by the first and second code signals.

By the way, it is extremely rare that disturbance light matches either the first or second code signal. Furthermore, it can be said that disturbance light rarely matches both the first and second code signals. Therefore, there is no possibility that the disturbance light is erroneously determined as the reflected light of the projection light from the light emitting element and that the object is present. Therefore, an object can be accurately detected without being affected by disturbance light.

[0012]

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 projects 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 according to 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 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 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.

The microcomputer 22 performs a timer operation. Further, the microcomputer 22 has a duty 5 at a predetermined frequency.
The light emission drive circuit 2 outputs a 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 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, for a certain period of time from the microcomputer 22,
If the light emission command signal F continues to be 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 the signal, shapes the waveform, generates a light receiving signal R, and outputs the signal to the microcomputer 22.

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, and the light receiving circuit 24 amplifies and outputs the detection signal. On the other hand, when no person stands in front of the morning glory 1, the projection light from the light emitting element 6a does not reflect. 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 blinks with the frequency of the light emission instruction signal F as a 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 24 and then shaping the waveform, a continuous light receiving signal R is obtained.

The light receiving element 6b outputs a detection signal in the same manner whether it receives reflected light of the light projected from the light emitting element 6a or disturbance light having the same wavelength as the light projected by the light emitting element 6a. I do. Therefore, the light receiving circuit 24 outputs the light receiving signal R 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.

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, a state in which the emission command signal F is output for C μsec and then stopped for C μsec is referred to as a code “1”. Also,
A state in which the output of the light emission command signal F is stopped for D μsec (= 2 C μsec) is referred to as a code “0”.

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

Therefore, in the light emission code A, the light emission command signal F is changed from Cμsec output → Dμsec output stop → Cμse
c output → Cμsec output stop → Cμsec output → Eμsec
(= 5 Cμsec) The output is performed in the order of output stop → Cμsec output → Cμsec output stop.

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 in accordance with the light emission code A (or B), and reflects the reflected light of the light projected from the light emitting element 6a.
Is received correctly, the light receiving signal R is output according to the light emission code A (or B).

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 (hereinafter, referred to as a person detection operation) in the embodiment configured as described above 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 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 emission code A, the light emitting element 6a emits light for a certain number of times in Cμsec → stops light emission for Dμsec → lights for a certain number of times in Cμsec → stops light emission for only Cμsec → lights for a certain number of times in Cμsec → Eμsec During this time, light emission is stopped for a certain number of times, and light emission is stopped for a certain number of times at C μsec.

Then, the flow shifts to S2. In S2,
The microcomputer 22 waits until a certain time elapses, and after the certain 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, based on the light emission code B, the light emitting element 6a emits light for a certain number of times in C μsec → stops emitting light for a period of Cμsec → emits light for a certain number of times in Cμsec → stops emitting light for a period of Dμsec → emits light for a certain number of times in Cμsec → Dμsec During this time, the light emission is stopped in a sequence of stopping light emission for a certain number of times at C μsec and stopping light emission only for D μsec.

Then, the flow shifts to S4. In S4,
The microcomputer 22 controls the light emitting element 6a in S1 and S3.
Light-receiving element 6 for light emission based on light-emitting codes A and B
b, light is received accurately, and it is determined whether or not the light receiving circuit 24 outputs the light receiving signal R according to each of the light emitting codes A, B.

That is, in S1, when a person stands in front of the morning glory 1 at the time when the light emitting element 6a is caused to emit light by the light emission command signal F of the light emission code A, the projection 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 receiving signal R obtained by amplifying the detection signal.

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

After a lapse of a predetermined time in S2, S
In 3, when the light-emitting element 6a is caused to emit light by the light-emitting command signal F of the light-emitting code B, if a person stands 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, and the light receiving circuit 24 outputs a light receiving signal R obtained by amplifying the detection signal.

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

Therefore, if the light receiving signal R is output from the light receiving circuit 24 in accordance with each of the light emitting codes A and B,
It can be seen that a person is standing for more than a certain time in front of. On the other hand, if the light receiving signal R according to each of the light emission codes A and B is not output from the light receiving circuit 24, it can be understood that no person has appeared before the morning glory 1 for a certain period of time.

When the light reception signal R according to the light emission code A is output but the light reception signal R according to the light emission code B is not output, a person simply crosses the front of the morning glory 1. You can see that.

Similarly, the light receiving 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 a person has just appeared in front of the morning glory 1.

When the light receiving circuit 24 outputs the light receiving signal R in accordance with each of the light emitting codes A and B, the process proceeds to S5, and outputs the light receiving signal R in accordance with at least one of the light emitting codes A and B. If not, the process proceeds to S6.

In step S5, the microcomputer 22 determines that a person is standing in front of the morning glory 1 and determines "human 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 no person is standing in front of the morning glory 1 and determines “non-detection”, and stores the determination result in the RAM. Then, the process proceeds to S7.

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

The microcomputer 22 detects a person in front of the morning glory 1 only when a light reception signal R according to each of the light emission codes A and B is output in response to the light emission by the two kinds of light emission codes A and B. (Ie, “human detection”).

On the other hand, when the light receiving signal R according to at least one of the light emission codes A and B is not output for the light emission by the two kinds of light emission codes A and B, the microcomputer 22 It is determined that a person is not standing in front (that is, “people not detected”).

When an inverter fluorescent lamp is used as an illumination of an installation place of the automatic morning glaze washing apparatus 1, periodic pulse-like noise may be generated as described above. However, it is very rare that the periodic pulse-like noise matches either of the light emission codes A and B, and it is unlikely that the noise coincides with both of the light emission codes A and B.

It can be said that disturbance light other than the periodic pulse-like noise rarely coincides with both the emission codes A and B. As described above, in the present embodiment, "human detection" is determined only when the light receiving signal R according to both the light emission codes A and B is output. Therefore, disturbance light such as periodic pulsed noise is not erroneously determined as “human detection” as reflected light of the projection light from the light emitting element 6a.

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

Then, when the determination result of “human detection” follows the determination result of “non-human 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, it is possible to comfortably add small items and to make the morning glory 1 difficult to stain.

Subsequently, when a determination result of "human non-detection" follows a determination result of "human detection", the microcomputer 22
Determines that the person who has completed the addition has left before the morning glory 1, and performs post-cleaning processing.

That is, the microcomputer 22 controls the valve drive circuit 2
By controlling the valve 1, the electromagnetic opening / closing valve 4 is opened for a predetermined time so that a certain amount of washing water is supplied from the water supply pipe 3 to the morning glory 1, and the morning glory 1 is washed.

As described above, in the automatic morning glory 1 cleaning apparatus, when a person who intends to add a small business stands in front of the 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.

Incidentally, the present invention is not limited to the above-described embodiment, but may be carried out with the following changes. 1) Each code “0” and “1” is appropriately set.
That is, after the light emission command signal F is output for an appropriate time, the state in which the output is stopped for the same time is referred to as a code “1”. Further, a state in which the output of the light emission command signal F is stopped for twice the appropriate time in the code “1” is referred to as a code “0”.

2) The light emission codes A and B are changed to each code "0".
An appropriate combination of an appropriate number of “1” is used. 3) The light emitting code is A. Instead of using two types of B, three or more types are prepared and implemented in the same manner as in the above embodiment.

4) The frequency of the light emission command signal F is an appropriate frequency within a range different from the lighting frequency of the inverter fluorescent lamp. Further, the frequency of the light emission command signal F in each of the light emission codes A and B is made different. For example, the frequency of the light emission command signal F in the light emission code A is XKHz, and the frequency of the light emission command signal F in the light emission code B is YKHz. In this case, an 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 a timer operation, a timer circuit is provided as a peripheral circuit of the microcomputer 22 and the timer circuit performs the timer operation. 6) The pre-cleaning process is performed when the determination result of “human detection” follows the determination result of “human detection” twice. After the determination result of “human detection” is followed by the determination result of “non-human detection” twice, the post-cleaning process is performed. In this case, even if a person simply crosses in front of the morning glory 1 or 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 performed incorrectly. To do it.

7) The emission command signal F is not a pulse wave with a duty of 50% but a pulse wave with an arbitrary duty. 8) Replace the lithium battery 8 with a DC power supply 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 visible light or ultraviolet light instead of infrared 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, a sound wave reflected from the ultrasonic speaker from the ultrasonic speaker hits the object is detected by the ultrasonic microphone.

11) 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. 12) Not only an automatic cleaning device for sanitary appliances but also other object detection devices such as automatic doors and FA devices.

13) The above-mentioned 1) to 12) are carried out by appropriately combining them.

[0066]

As described above in detail, 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 the 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 toilet for men (morning glory).

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 time chart showing light emission codes A and B.

FIG. 5 is a flowchart illustrating a human detection operation according to 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

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-157333 (JP, A) JP-A-4-230888 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01V 8/10 E03D 5/10

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).
b) detecting an object by detecting the object, wherein the first code signal for causing the light emitting element (6a) to emit light in a predetermined pattern is output, and the light emitting element (6a) is output.
Code generating means (2) for outputting a second code signal for causing the light to emit in a pattern different from the predetermined pattern.
2) First, based on the first code signal, the light emitting element (6)
a) is caused to emit light in a certain pattern, and after a certain period of time, the light-emitting element (6a) is caused to emit light in a pattern different from the previous certain pattern based on the second code signal. It is determined that an object is present only when the light receiving element (6b) receives both reflected lights with respect to the light emission of the light emitting element (6a) by the code signal of No. 2 and both or any one of them is determined. An object detection device, comprising: a control judging means (22) for judging that no object exists when the light receiving element (6b) does not receive reflected light.