JP2889445B2 - 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 disturbance light is generated. That is, it cannot be determined whether or not the object is detected, and an 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 that object detection apparatus, originating
The optical element emits light multiple times at irregular time intervals to
The object detection operation for determining the presence is repeatedly performed , and when it is determined that the object is present in the previous object detection operation, in the current object detection operation, the reflected light is emitted for a plurality of light emission of the light emitting element. When the light receiving element receives light for at least the first set number of times, it is determined that an object is present. When the light receiving element receives light for less than the first set number of times, it is determined that no object is present. Is determined not to exist, in the current object detection operation, the object is present when the light receiving element receives the reflected light for a plurality of times of light emission of the light emitting element for the second set number of times or more. And a control determination device that determines that the object does not exist when light is received only less than or equal to the second set number of times.
The gist is that the second set number is set to a value larger than the first set number.

[0010]

Therefore, according to the present invention, when it is determined that an object is present in the previous object detection operation, it is easy to determine that an object is present this time, and the object is detected in the previous object detection operation. When it is determined that the object does not exist, it is easy to determine that the object does not exist again.

For this reason, once the presence of an object is detected, even if a little disturbance light occurs thereafter, it is determined that the object is present in the subsequent object detection operation. Further, once it is detected that an object does not exist, even if a little disturbance light is generated thereafter, it is determined that the object does not exist in the subsequent object detection operation.

As a result, even if some disturbance light is generated, the determination of the object detection operation does not differ every time, and the instability of the object detection result can be eliminated.

[0013]

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 preset 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 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 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.

The microcomputer 22 performs a timing operation and a counting operation. In addition, microcomputer 2
2 is a switching circuit 2 for a fixed time every time T interval.
4 to output a command signal S.

Further, the microcomputer 22 has a function of generating a random number having an appropriate number of digits set in advance. In the ROM in the microcomputer 22, an arbitrary numerical value having the same number of digits as the generated random number and data of an appropriate time corresponding to the numerical value (hereinafter referred to as time data) are stored in a table in advance.

The microcomputer 22 checks a table set in the ROM (hereinafter referred to as a ROM table) with the generated random numbers, and selects time data corresponding to the random numbers.
Note that the time data takes a sufficiently small value with respect to the output interval of the command signal S. For example, the time data (time t) is set to about 1/100 of the output interval (time T) of the command signal S.

Then, the microcomputer 22 outputs a light emission signal F based on the obtained time data. Valve drive circuit 21
Opens and closes the electromagnetic 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 open / close state of the solenoid on-off valve 4 is switched,
When the timing signal is not output, the previous open / closed state is kept as it is.

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.

The light receiving circuit 25 becomes operable only when power is supplied from the switching circuit 24.
Since the command signal S from the microcomputer 22 is output for a certain period of time at intervals of time T, the switching circuit 24 also supplies power to the light receiving circuit 25 for a certain period of time at intervals of time T. Therefore, the light receiving circuit 25 is operable with the power supply being turned on for a fixed time at every time T interval.

The light receiving circuit 25 amplifies the detection signal of the light receiving element 6b and outputs it to the microcomputer 22 as a light receiving signal R.
The light receiving element 6b outputs a detection signal in the same manner regardless of whether reflected light of the light projected from the light emitting element 6a is received or disturbance light having the same wavelength as the light projected from the light emitting element 6a. Therefore, the light receiving circuit 25 outputs the light receiving signal R in the same manner regardless of whether the light reflected from the light projected from the light emitting element 6a is received or the disturbance light having the same wavelength as the light projected from the light emitting element 6a.

The light emission drive circuit 23 causes the light emitting element 6a to emit light based on the light emission signal F from the microcomputer 22. Next, the morning glory 1 in the present embodiment configured as described above.
Action to detect if a person is standing in front of
The operation will be described with reference to flowcharts shown in FIGS.

FIGS. 4 and 5 are flowcharts showing the main routine. FIG. 6 is a flowchart showing a subroutine of a count process, and FIG. 7 is a flowchart showing a subroutine of a wait process.

As shown in FIGS. 4 and 5, 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 returns the count value to "0" in order to start the counting operation. Then, the process proceeds to S3. In S3, the process proceeds to a subroutine of a counting process.

That is, as shown in FIG.
In 1, the microcomputer 22 outputs a light emission signal F to the light emission drive circuit 23. Then, the light emission drive circuit 23 causes the light emitting element 6a to emit light based on the light emission signal F. And
The process moves to S32.

In S32, 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, and the light receiving circuit 25 outputs a light receiving signal R obtained by amplifying the detection signal.

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 has been output, the process proceeds to S33, and if not, the process proceeds to S4 of the main routine. At S33, the microcomputer 22 increments the count value. Then, in S4, the process proceeds to S4 of the main routine, the process proceeds to a subroutine of the wait process.

That is, as shown in FIG.
In step 1, the microcomputer 22 generates a random number having an appropriate number of digits set in advance. Then, control goes to a step S42. S4
In step 2, the microcomputer 22 compares the generated random number with the ROM table and selects time data corresponding to the numerical value of the random number. The time data is set in advance so as to be the time t. Then, control goes to a step S43.

In S43, the microcomputer 22 waits until the time corresponding to the selected time data elapses, and after the elapse of the time, shifts to S5 of the main routine.
In steps S21 to S21, the counting process and the weighting process are alternately repeated. Then, when the tenth counting process is completed in S21, the process proceeds to S22 of the main routine shown in FIG.

Each weight processing S4, S6, S8, S
The time data selected in 10, S12, S14, S16, S18, and S20 is time t. Therefore,
The time required for each weight process is sufficiently shorter than the cycle (time T) of the main routine.

At S22, the RAM in the microcomputer 22
If the determination result of the previous human detection operation stored in step S23 is “human detection”, the process proceeds to step S23, and if “human non-detection”, the process proceeds to step S23.
Move to 24.

That is, the main routine of this human detection operation is repeated at intervals of time T. As will be described later, a determination result of "human detection" or "non-human detection" is stored in the RAM for each routine. It is memorized. Therefore, the determination result of the previous main routine stored in the RAM is referred to.

In S23, if the count value is equal to or less than "7", the flow proceeds to S25, and if it is "8" or more, the flow proceeds to S56. In S25, 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 S27.

On the other hand, in S26, the microcomputer 22 determines that a person is standing in front of the morning glory 1 and determines that "person detection" has been performed.
The result of the determination is stored in the RAM. Then, control goes to a step S27.

In S27, the microcomputer 22 stops outputting the command signal S to the switching circuit 24. Therefore, the switching circuit 24 is turned off, and the light receiving circuit 25 is turned off.
Cut off the power supply to the Then, the power of the light receiving circuit 25 is turned off and the operation stops. Then, the process returns to S1.

On the other hand, in S24, the count value becomes "1".
If "0", the process proceeds to S28, and if not "10", S2.
Move to 9. In S28, the microcomputer 22 sets the morning glory 1
Is determined to be "human detection" as a person stands in front of, and the determination result is stored in the RAM. Then, control goes to a step S27.

On the other hand, in S29, the microcomputer 22 determines that no person is standing in front of the morning glory 1 and determines that "person is not detected", and stores the determination result in the RAM. And S27
Move to.

As described above, in this embodiment, the light-emitting element 6a emits light intermittently at a constant period of time T, and emits light 10 times in one period. The microcomputer 22 generates a random number every time the light emitting element 6a emits light, and selects the light emitting interval of the light emitting element 6a by comparing the random number with a ROM table. Therefore, the light emission interval of the light emitting element 6a is random based on the generated random number.

Each time the light receiving element 6b receives light, the microcomputer 22 increments the count value. Subsequently, when the result of the previous main routine is “human detection”, if the count value is “7” or less, it is determined to be “non-human detection”; I do.

That is, when the previous determination result is "human detection", if the light-receiving element 6b can receive no more than 7 times of light emission of the light-emitting element 6a ten times, this time is "non-human detection". It is determined that there is, and if the light receiving element 6b can receive light eight times or more, it is also determined that the detection is “human detection”.

When the result of the previous main routine is "non-human detection", if the count value is "10", "human detection" is determined, and if the count value is not "10", "human detection" is determined. Not detected "is determined.

That is, the result of the previous determination is “no person detected”.
In the case of, if the light receiving element 6b can receive all 10 times of the light emission of the light emitting element 6a for 10 times, it is determined to be "human detection" this time, and if the light receiving element 6b cannot receive even one time, this time Is also determined to be “non-human detection”.

Therefore, when the previous determination result is “human detection”, the present determination result is also likely to be “human detection”, and when the previous determination result is “non-human detection”, the current determination result is also It is easy to be "non-detected". In other words, "hysteresis" is added to the human detection operation.

As described in detail above, in this embodiment, the light emitting element 6a emits light 10 times at random light emitting intervals.
Even if periodic disturbance light is generated, it is unlikely that the disturbance light completely matches the light emission of the light emitting element 6a. Therefore, the present embodiment can accurately detect the presence of a person without being affected by the periodic pulse noise as described above.

In addition, by adding "hysteresis" to the human detection operation, once the determination result of "human detection" comes out, even if a little disturbance light is generated for some reason thereafter, the subsequent human detection operation Then, the determination of "human detection" will be continued.

Further, once the determination result of "non-detection of human" is obtained, even if a little disturbance light is generated thereafter, the determination of "non-detection of human" is continued in the subsequent human detection operation.

Therefore, even if some disturbance light occurs, the determination result of the human detection operation does not differ every time, and a stable determination result can be obtained. Even when the operation of the light emission drive circuit 23 and the light reception circuit 25 is unstable, a stable determination result can be obtained.

Incidentally, since the light receiving circuit 25 becomes operable at intervals of time T, the above routine is repeated at intervals of time T. 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" continues twice after the determination result of "non-detection of human", 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 in 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 person standing in front of the morning glory 1 has stopped for the time T or more, and it is not merely crossing in front of the morning glory 1 but small You are trying to add

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 a result, it is possible to comfortably add small items and to make the morning glory 1 difficult to stain.

Subsequently, when 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. That is, if the determination result of “people non-detection” is repeated twice, there is no person for more than the time T in front of the morning glory 1, and it can be surely confirmed that the person who has completed the small-work has left. is there.

Then, the microcomputer 22 controls the valve drive circuit 21 to open the electromagnetic on-off 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.
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 product 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 implemented with the following changes. 1) The number of times of light emission of the light emitting element 6a in one cycle is not 10 but an appropriate number.

[0064] 2) is set to an appropriate time interval without a common divisor of the light - emitting interval, similarly to the above-described embodiment, it is effective against periodic pulse-like noise.

3) Instead of causing the microcomputer 22 to perform a counting operation, a counting circuit is provided as a peripheral circuit of the microcomputer 22 and the counting circuit performs the counting operation. 4) The interval at which the command signal S is output from the microcomputer 22 is
An appropriate time is set instead of the time T. That is, the light emission period of the light emitting element 6a is set appropriately.

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 non-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) Instead of causing the microcomputer 22 to perform a timekeeping operation, a timer circuit is provided as a peripheral circuit of the microcomputer 22 and the timer circuit performs the timekeeping operation. 7) Replace the microcomputer 22 with an external device such as a personal computer.

8) The light emission signal F is a plurality of pulses having an appropriate frequency and an arbitrary duty. For example, 10KHz
The light emission signal F is composed of ten pulses with a duty of 80%.

9) The lithium battery 8 is replaced with a DC power supply, and power is supplied from a commercial power supply. 10) 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.

11) 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 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.

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

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

[0073]

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 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 flush toilet for men according to one embodiment.

FIG. 3 is a front view of the flush urinal for men shown in FIG. 2;

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

FIG. 5 is a flowchart illustrating a main routine of a human detection operation in one embodiment.

FIG. 6 is a flowchart illustrating a subroutine of a count process of a human detection operation in one embodiment.

FIG. 7 is a flowchart illustrating a subroutine of a wait process of a human detection operation in one embodiment.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-296680 (JP, A) JP-A-2-300687 (JP, A) JP-A-2-7592 (JP, U) 77896 (JP, B2) JP 3-32030 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01V 9/04 E03D 5/10 G01J 1/02 G01J 1/42- 1/44

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 apparatus detect an object by detecting by b), a plurality of times to emit light emitting element (6a) at irregular time intervals
Repeat the object detection operation to determine the presence of the object
If it is determined in the previous object detection operation that an object is present, in the current object detection operation, the light-receiving element (6b) receives the reflected light from the light-emitting element (6a) for a plurality of light-emissions. It is determined that an object is present when light is received more than the set number of times, and it is determined that an object is not present when light is received less than the first set number of times, and no object is present in the previous object detection operation. In the object detection operation of this time, the object is present when the light receiving element (6b) receives the reflected light more than the second set number of times for the light emission of the light emitting element (6a) a plurality of times. And the second
An object characterized by comprising a control determining device (22) for determining that an object does not exist when light is received no more than the set number of times, and wherein the second set number is set to a value larger than the first set number. Detection device.