JP4006547B2 - Object detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention generally relates to an object detection apparatus including a human body, and more particularly to an object detection apparatus that determines the approach or separation of an object using the Doppler effect of radio waves.
The radio wave belongs to a frequency band of 10 KHz to 100 GHz such as an ultrasonic wave, a microwave, or a millimeter wave.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been used an apparatus that detects that a person is in front of a urinal with infrared rays or the like, and performs cleaning by opening a flash valve when the person disappears. However, infrared detectors are easily noticeable to those who are there, and give the impression of being monitored to the user using the urinal. In addition, a plastic window that transmits infrared rays is required, which is not preferable because of detection failure due to mischief and the like. Therefore, in recent years, a microwave is transmitted from the inside of the instrument, a signal (Doppler signal) reflected from the human body is detected, and the high frequency and low frequency of the detection signal continue for a predetermined time or more. Cleaning is performed by opening the flush valve (see, for example, Patent Document 1).
[0003]
Also, a microwave is transmitted, a signal (Doppler signal) reflected from the human body is detected, a power spectrum of the detection signal is obtained, and the human body is reduced from the shift and duration of the peak of the power spectrum. There is also a method for determining whether the person has approached or moved away from the toilet (see, for example, Patent Document 2).
[0004]
[Patent Document 1]
Japanese Utility Model Publication No. 63-145973 (page 4-9, Fig. 2)
[Patent Document 2]
Japanese Patent Laid-Open No. 9-80150 (page 3-7, FIG. 2)
[0005]
[Problems to be solved by the invention]
However, the movement modes such as the relative movement direction and movement speed of the human body with respect to the urinal vary depending on the situation. Such various movements produce various Doppler frequency signal patterns. For this reason, the human body has different radio wave reflectivities in the method for determining whether detection in a plurality of frequency bands has occurred in a certain order as described above or the method for determining by the duration of the peak of the power spectrum. Therefore, it is difficult to make a judgment only by the power of the radio wave, and it is difficult to reliably pick up only the mode using the urinal from various modes of movement. For example, a user who approaches the urinal slowly or a user who suddenly appears from the side of the urinal is not necessarily detected. In addition, a person passing through the urinal may be erroneously detected. Moreover, when several people use a urinal continuously, each person's detection is difficult. Similar problems also exist in devices other than urinals and human body detection devices provided in facilities.
[0006]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to make it possible to accurately detect the approach or separation of a person from the frequency of an output signal or the rate of increase or decrease in an object detection apparatus using the Doppler effect of radio waves.
[0007]
Another object of the present invention is to prevent false detection caused by use of a plurality of persons in an apparatus for use by a plurality of different people such as a urinal or an object detection apparatus applied to a facility.
[0008]
[Means for solving the problems and actions / effects]
  According to one aspect of the present invention, a transmission unit that transmits a radio wave to the outside as a transmission signal, a reception unit that receives a reflected wave from a detection target as a reception signal, and a low-frequency output from the transmission signal and the reception signal A sensor unit that extracts a signal, and an extreme value that is a maximum value as a change point from the rise to the fall of the output signal of the mixer unit, or a minimum value as a change point that changes from a fall to an increase Peak storage means for storing extreme values, inclination calculation means for calculating the inclination between extreme values stored in the peak storage means, frequency calculation means for calculating the frequency of the output signal, inclination calculation means and frequency calculation Determination means for determining whether the detection object is approaching or away from the sensor unit from the calculation result of the means, and the determination means comprises:SaidWhen the frequency of the output signal calculated by the frequency calculation means is higher than the preset frequency,There is provided an object detection apparatus characterized by performing any of the following determinations (x) and (y).
(X) When the extreme value stored in the peak storage means is the maximum of the repeated amplitude of the output signal, the inclination calculated by the inclination calculation means is stored, and the calculated inclination and the previous calculation are calculated. The following (x-1) or (x-2) is determined based on the rate of change from the slope.
(X-1) When the change is an increase and is greater than a preset change rate, it is determined that the detection target is approaching the sensor unit.
(X-2) When the change is a decrease and is smaller than a preset change rate, it is determined that the detection target is far away from the sensor unit.
(Y) When the extreme value stored in the peak storage means is the minimum of the repeated amplitude of the output signal, the inclination calculated by the inclination calculation means is stored, and the calculated inclination and the previous calculation are calculated. The following (y-1) or (y-2) is determined based on the rate of change from the slope.
(Y-1) When the change is decreasing and smaller than a preset change rate, it is determined that the detection object is approaching the sensor unit.
(Y-2) When the change is an increase and is larger than a preset change rate, it is determined that the detection target is far away from the sensor unit.
[0009]
In general, when a person approaches, the amplitude value of the Doppler signal, which is a detection signal, increases as it approaches, and the method of the increase is not proportional, and increases in a quadratic function at a certain point. , The amplitude value of the Doppler signal, which is the detection signal, decreases as it moves away, and decreases as it moves away. Decrease. The frequency at that time is a frequency corresponding to the approaching speed. As for the frequency at this time, an object moving in a parallel direction with respect to the transmission direction of the radio wave transmitted from the sensor unit can obtain a frequency according to the moving speed, but the more perpendicular to the transmission direction of the radio wave, the more the frequency becomes. The frequency value is smaller than the frequency corresponding to the actual moving speed.
Therefore, because the frequency of the detected Doppler signal is larger than the preset frequency value, the detection object does not pass by the side of the sensor unit, but is approaching or moving away from the sensor unit. To determine whether the object to be detected is approaching or moving away from the sensor unit based on the slope between the extreme values stored by the peak storage means. Can do.
[0010]
More preferably, when calculating the inclination between extreme values, it is possible to reliably detect the movement of the human body by calculating the inclination between successive extreme values stored by the peak storage means.
By doing this, even if the extreme value is smaller than the normal approach because the person approached faster than usual, such as the difference in radio wave reflectivity by the person, the Doppler signal that is the detection signal is missed. Therefore, it is possible to reliably detect the movement of the human body.
[0011]
Further, the extreme value stored by the peak storage means is not particularly limited by the maximum value or the minimum value of the repeated amplitude of the Doppler signal.
[0013]
Generally, when the extreme value stored by the peak storage means is the maximum value of the repeated amplitude of the Doppler signal when a person approaches, the slope calculated by the slope calculation means becomes positive. And the inclination calculated by the inclination calculation means becomes abruptly large at a certain point, and the Doppler signal hardly changes when there is nothing near the front of the sensor, but the human body moves when the person approaches A Doppler signal with a frequency corresponding to the speed is obtained, and a Doppler signal larger than a preset frequency value is obtained, so that the human body just passes by the side of the sensor unit, or approaches or moves away. It is possible to determine whether or not a certain operation is being performed.
Further, it is possible to determine whether the human body is approaching or moving away from the object detection device based on the inclination calculated by the inclination calculating means at that time.
[0014]
In the above description, the method using the maximum value as the extreme value is described when a person approaches, but when the minimum value is used as the extreme value, the slope is negative and decreases rapidly. . Similarly, when a person leaves, the sign of the inclination and the increase / decrease are opposite to those when approaching.
[0015]
The amplitude value of the Doppler signal output when a person is approaching or moving away varies depending on the size of the person (detection target) and the movement mode, and is large if the detection target is an adult. An amplitude value can be obtained, and if the object to be detected is a child, only a small amplitude value can be obtained. It wasn't a reliable method.
Therefore, by focusing on the fact that the maximum value or minimum value of the amplitude value always changes as the detection object approaches or moves away as in the above configuration, what kind of detection object is determined by judging from the inclination. Therefore, it is possible to make a determination of approach or separation with certainty.
[0017]
When the judgment is made only by the inclination calculated by the inclination detecting means, for example, when the object detection device is incorporated in a simultaneous device, and the person approaches the adjacent device, the amplitude value is small. It is possible to obtain a Doppler signal as a detection signal, and it may be determined that a person is approaching depending on the magnitude of a preset inclination.
Therefore, according to the above configuration, by using the rate of change in the inclination calculated by the inclination calculating means, even when the object detection device is incorporated in a simultaneous device, it approaches the device that is originally the detection target. When the signal comes, the amplitude value of the Doppler signal, which is the output signal, increases in a quadratic function, so the rate of change increases accordingly, but the detection signal obtained when approaching the next device Since the device itself is small, the rate of change in inclination hardly changes, and it is possible to reliably detect only an object approaching the device that is the detection target.
[0018]
  Claim2The invention described is the claim.1In the urinal device provided with the object detection device described above, it is characterized by comprising a control means for performing preliminary cleaning when it is determined by the determination means that the human body has approached and for performing main cleaning when the human body has moved away. To do.
[0019]
In general, the Doppler signal that is detected until a person approaches the urinal, adds use, and leaves is a Doppler signal of a certain frequency that gradually increases in amplitude while the person is approaching. While added, the Doppler signal detected because there is almost no movement of the human body is also a substantially constant signal with almost no amplitude and frequency. It is a Doppler signal.
Especially in urinal devices that perform automatic cleaning, because human body detection is performed using infrared reflection, problems that occur when wearing clothes that do not reflect infrared rays, or in front of urinal devices However, according to the above configuration, it is possible to reliably determine whether the human body is approaching or moving away, so it is possible to reliably perform preliminary cleaning and main cleaning. This makes it possible to improve the washability of the toilet and prevent flushing wasteful water.
[0020]
As described above, according to the present invention, the object detection device that reliably determines the approach and separation of the detection object from the inclination of the extreme value of the Doppler signal as the detection signal, the rate of change in inclination and the frequency thereof. Can be provided.
[0021]
In addition, even in an environment where the object detection device is provided, it is possible to reliably distinguish between an object approaching an adjacent device and an object approaching the device.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0023]
The detection operation of the object detection device, which is the gist of the present invention, will be described in detail.
The apparatus performs a detection operation using radio waves. As shown in FIG. 1, a transmission unit 14 that generates a transmission signal for transmitting a signal to the outside as a radio wave, and a microwave near 10 GHz as a transmission wave. , A receiving unit 13 that receives a reflected wave from the detection object 11 of the microwave transmitted from the transmitting unit 12, and a low-frequency output signal is extracted based on the transmission signal and the received signal Between the mixer unit 15, the peak storage unit 16 that stores the maximum value or the minimum value of the repeated amplitude of the low-frequency signal output from the mixer unit 15, and between the extreme values stored in the peak storage unit 16 An inclination calculating unit 17 that calculates an inclination and a frequency calculating unit 18 that calculates the frequency of a low-frequency signal output from the mixer unit 15 are provided.
[0024]
FIG. 2 shows a waveform of an output signal when an object approaches the device. The peak storage unit 16 samples the amplitude values 21a to 21m of the low frequency output signal output from the mixer unit 15 at a certain sampling period. For example, in the case of obtaining the maximum value of the repeated amplitude, the sampled amplitude values 21a to 21c continuously increase, and 21e to 21g continuously decrease at a certain point 21d as a boundary. Is the maximum value (extreme value), and the maximum value can be calculated by obtaining the change point.
Similarly, when the minimum value of the repeated amplitude is obtained, the sampled amplitude values 21h to 21j continue to decrease and continuously increase 21k to 21m at a certain point, and the change The point is the minimum value (extreme value).
[0025]
In the above description, the waveform when the object approaches the device has been described. However, the method of calculating the extreme value is the same even when the object moves away from the device.
In addition, even if it continues to rise and then falls continuously at a certain point, it may not be determined as an extreme value due to the influence of noise etc. mixed in the signal. It is possible to reliably calculate the extreme value by adding a condition that the value is not determined to be an extreme value unless it continues for a preset time, or is not greater than or less than a preset amplitude value.
In this description, the sampling is performed at a certain sampling period. However, for example, when it is assumed that a human body walking is detected, the walking speed of the human body is about 4 km / h (Doppler frequency = about 77 Hz). It is desirable to sample at 1 kHz or higher in order to reliably sample repeated extreme values (since 10 or more points can be sampled in one cycle), it goes without saying that the earlier the sampling cycle, the better the measurement accuracy.
[0026]
FIG. 3 shows a waveform of an output signal when an object approaches the apparatus, and a method of calculating an inclination by an inclination calculating unit will be described.
If the two extreme values stored by the peak storage means are 31a and 31b, the amplitude value at the extreme value 31a is a1, the time is t1, the amplitude value at the extreme value 31b is a2, and the time is t2, the slope calculation means The inclination can be calculated by (a2-a1) / (t2-t1).
Here, when the extreme value stored by the peak storage means is the maximum value, the slope calculated by the slope calculation means is positive, and conversely, the extreme value stored by the peak storage means is the minimum value. In this case, the inclination calculated by the inclination calculating means is negative.
Similarly, when the object moves away from the apparatus, the extreme value stored by the peak storage means is negative when it is the maximum value, and positive when it is the minimum value.
[0027]
In addition, if the slope between extreme values that are too far apart is calculated, there is a possibility of false detection without inclination even though the approach has ended, so the peak storage means used when calculating the slope As for the stored extreme value, it is desirable to calculate the inclination between two consecutive poles.
[0028]
The frequency calculation method by the frequency calculation means can be easily calculated using 1 / (time between two consecutive peaks) from the time between two consecutive peaks stored by the peak storage means.
There is also a method of obtaining the frequency of the output signal from the frequency spectrum distribution by performing FFT (Fast Fourier Transform) on the output signal output from the mixer unit.
[0029]
Based on the slope between the extreme values and the frequency of the output signal calculated by the method described in the above description, the judging means determines whether the object is approaching the object detection device according to the flowchart shown in FIG. Determine if you are far away.
The flowchart of FIG. 4 shows a control flow when the extreme value stored by the peak storage means is the maximum value.
[0030]
The determination means first determines whether the extreme value stored in the peak storage means is the maximum value or the minimum value. For example, when the extreme value stored in the peak storage means is the maximum value, Next, it is determined whether the frequency of the signal output from the mixer calculated by the frequency calculation means is higher or lower than a preset frequency (S41). If the frequency is lower than the preset frequency, it is determined that the detection target is not moving, and the determination is completed.
If the frequency is high, that is, if it is determined that the detection target is moving, then it is determined whether the inclination calculated by the inclination calculating means is positive or negative (S42). Here, if the tilt is positive, the detection target may be approaching the device, and if the tilt is negative, the detection target may be far from the device. There is sex.
If the tilt is positive, if the tilt is larger than the preset tilt, the detection object is judged to be approaching the device. If the tilt is less than the preset tilt, both the approach and the remote are detected. It is determined that it cannot be said, and the determination ends (S43). If the inclination is negative, if the inclination is smaller than the preset inclination, it is determined that the detection target is far away from the device, and the inclination is larger than the preset inclination. It is determined that neither can be approached nor separated, and the determination ends (S44).
[0031]
Similarly, it is possible to determine approaching or moving away even when the extreme value stored by the peak storage means is the minimum value.
Here, since the judgment means is judged by a microcomputer or the like, the preset frequency and the threshold value of the slope can be changed by writing software, or can be changed by using a dip switch, an external input element, etc. Needless to say, it improves usability.
[0032]
In addition, it is possible to reduce false detection by judging not only the gradient of the extreme value stored in the peak storage unit as shown in FIG. 5 but also the rate of change of the gradient (change rate of the gradient). Become.
As shown in FIG. 5, when the inclination calculated by the inclination calculating means is 51b and the previously calculated inclination is 51a, the inclination ratio (change rate) is calculated as 51b / 51a. Since the inclination ratio (change rate) can be reliably detected that the inclination changes regardless of the magnitude of the signal, if the inclination is relatively increased even if the inclination is small, it is detected. be able to.
[0033]
FIG. 6 shows a flowchart of approach / separation determination using the inclination ratio (change rate).
The flowchart of FIG. 6 shows a control flow when the extreme value stored by the peak storage means is the maximum value.
The determination means first determines whether the extreme value stored in the peak storage means is the maximum value or the minimum value. For example, when the extreme value stored in the peak storage means is the maximum value, Next, it is determined whether the frequency of the signal output from the mixer calculated by the frequency calculating means is higher or lower than a preset frequency (S61). If the frequency is lower than the preset frequency, it is determined that the detection target is not moving, and the determination is completed.
If the frequency is high, that is, if it is determined that the detection target is moving, then it is determined whether the inclination calculated by the inclination calculating means is positive or negative (S62). Here, if the tilt is positive, the detection target may be approaching the device, and if the tilt is negative, the detection target may be far from the device. There is sex.
If the slope is positive, if the rate of change from the previously calculated slope is greater than the preset rate of change, the detected object is judged to be approaching the device, and the set rate of change is met. If not, it is determined that neither approach nor distance can be said, and the determination ends (S63). When the slope is negative, if the rate of change from the previously calculated slope is smaller than the preset rate of change, the detection object is determined to be far away from the device and set. If the rate of change is larger than the change rate, it is determined that neither approach nor distance can be said, and the determination ends (S64).
[0034]
As in the above configuration, the method of calculating the inclination or the rate of change in inclination with the maximum or minimum of the repeated amplitude of the output signal as an extreme value has been described, but the center of the output Doppler signal (the Doppler signal cannot be obtained) By performing full-wave rectification on the basis of a signal having an amplitude of 0, the maximum and minimum of the repeated amplitude of the output signal are always displayed as the maximum.
Therefore, by storing the maximum expressed by the full-wave rectification as an extreme value, it is possible to calculate the inclination and the rate of change of the inclination.
[0035]
FIG. 7 shows a urinal apparatus incorporating the object detection apparatus of the present invention, FIG. 8 shows a waveform obtained as an output signal, and FIG. 9 shows a control flowchart when the object detection apparatus of the present invention is incorporated in the urinal apparatus. Indicates.
[0036]
According to the present embodiment, the object detection device 72 of the present invention is installed inside the urinal 73 and transmits radio waves toward the human body 71. A series of operations performed when the human body 71 uses the urinal is a basic pattern of three patterns of 82 approaching the urinal, 83 adding the urinal, and 84 away from the urinal, and has a waveform as shown in FIG. 81.
Therefore, as shown in the flowchart of FIG. 9, when it is determined that the human body has approached the urinal using the object detection device of the present invention (S91), pre-cleaning is performed to make the urinal difficult to get dirty ( When it is determined that the human body has moved away (S93), the main cleaning is performed to clean the urinal (S94).
[0037]
In the method of judging the approach or separation of an object by comparing the increase and decrease of the amplitude of the received signal repeatedly with a preset threshold value, for example, when incorporated in the urinal device, the human body as a detection target It is necessary to assume both adults and children, and the amplitude value depends on the size of the human body, so the threshold value set for adults may be exceeded, but the threshold value may not be exceeded for children because the amplitude value is small There was a cause of false detection.
Therefore, by incorporating the object detection device of the present invention into a urinal device, the amplitude increases without being influenced by the magnitude of the amplitude value in order to determine whether the human body is approaching or moving away from the inclination of the extreme value of the output signal. It is possible to judge the decrease.
[0038]
In particular, in the case of an office or a station building where a urinal apparatus as shown in FIG. 10 is connected, there is a risk of detecting a human body 104 walking without using a urinal or a human body 103 using an adjacent urinal. Even though it is not used originally, there is a possibility that the “approach” of the human body may be judged, and not only the inclination by the inclination calculating means but also the ratio (change rate) of the inclination is used as a judging means. As a result, false detection can be further reduced.
[0039]
FIG. 11 shows a view in which the object detection device of the present invention is incorporated in a warm water washing toilet seat.
According to the present embodiment, by incorporating the object detection device 111 of the present invention into the warm water washing toilet seat 112, the approach of the human body 113 is determined, the toilet lid is automatically opened, and the human body is moved away (separated). This makes it possible to automatically close the stool lid, improving usability.
[0040]
Recently, household appliances that reduce power consumption are the mainstream, and even hot water toilet seat devices use large amounts of power such as hot water storage tanks and toilet seat heaters, and the main power supply (outlet) is turned on and off each time it is used. This is troublesome, and if the hot water storage tank or toilet seat heater is turned on while the power is always turned on, it has become a big problem in terms of energy saving.
However, in recent products, a control method such as turning on the hot water storage tank or toilet seat heater by detecting the seating of the human body on the toilet seat has been taken. When I put on the toilet seat heater, I felt very uncomfortable because it was cold when I sat down and it took time to warm up.
Therefore, by using the object detection device of the present invention, it is possible to turn on the hot water storage tank and the toilet seat heater by detecting that the human body is approaching the warm water washing toilet seat, and determine that the human body has moved out. Since the power can be turned off, not only the usability is improved, but also the power consumption can be greatly reduced.
[0041]
By performing the human body detection by the radio wave type of the present invention as in this embodiment, the human body detection device can be completely concealed in the urinal, particularly when a microwave band that passes through ceramics is used. It becomes possible, and it is possible not only to protect design restrictions and urinals from mischief, but also to be particularly concerned about the radiation direction because it is a radio wave type that spreads radially unlike an infrared photoelectric sensor. It is also possible to perform human body detection without any problem.
[0042]
Conventionally, warm water flush toilet seats, etc., have mostly used infrared rays as human body detection sensors, and the detection distance needs to be as long as possible when controlling the opening and closing of the toilet lid by approaching or moving away from the human body. For this reason, there is a problem in that not only a person approaching the toilet seat but also a person passing in front of the toilet is erroneously detected by trying to extend the detection distance far.
Therefore, by using this object detection device, it is possible to easily determine whether the detection target is approaching or moving away even though the detection distance is long because it is a radio wave type.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an object detection apparatus according to the present invention.
FIG. 2 is an output waveform diagram showing an extreme value calculation method by a peak storage unit according to the present invention.
FIG. 3 is an output waveform diagram showing an inclination calculation method by an inclination calculation means according to the present invention.
FIG. 4 is a flow chart showing criteria for approaching and moving away by a judging means according to the present invention.
FIG. 5 is an output waveform diagram showing a calculation method of a slope ratio (change rate) according to the present invention.
FIG. 6 is a flowchart showing the approach and separation criteria using the inclination ratio by the judging means according to the present invention.
FIG. 7 is a diagram in which an object detection device according to the present invention is mounted on a urinal device.
FIG. 8 is an output waveform diagram when the object detection device according to the present invention is mounted on a urinal device.
FIG. 9 is a control flowchart when the object detection device according to the present invention is installed in a urinal device.
FIG. 10 is a view showing that the object detection apparatus according to the present invention is mounted on a urinal apparatus that is provided in a row.
FIG. 11 is a diagram in which an object detection device according to the present invention is mounted on a warm water washing toilet seat.
[Explanation of symbols]
11: detection object, 12: transmission unit, 13: reception unit, 14: transmission unit, 15: mixer unit, 16: peak storage unit, 17: slope calculation unit, 18: frequency calculation unit, 19: determination unit, 21a 21 m: sampling value, 22: maximum value, 23: minimum value, 24: output signal, 31a, 31b: extreme value, 51a, 51b: inclination, 71: detection target (human body), 72: object detection device, 73 : Urinal device, 81: output signal, 82: approaching, 83: during small use, 84: during separation, 101a to 101c: object detection device, 102a to 102d: urinal device, 103: human body during use 104: Human body walking behind the urinal device, 111: Object detection device, 112: Toilet with hot water flush toilet seat, 113: Human body

Claims (2)

A transmission unit that transmits radio waves to the outside as a transmission signal, a reception unit that receives a reflected wave from a detection object as a reception signal, and a mixer unit that extracts a low-frequency output signal from the transmission signal and the reception signal, Having a sensor unit;
Peak storage means for storing an extreme value that is a maximum value as a changing point that turns from rising to falling or an extreme value that is a minimum value as a changing point that goes from falling to rising;
Slope calculating means for calculating the slope between extreme values stored in the peak storage means;
Frequency calculating means for calculating the frequency of the output signal;
From the calculation results of the inclination calculation means and the frequency calculation means, a determination means for determining whether the detection object is approaching or away from the sensor unit;
With
The judgment unit may, objects, wherein the when the frequency of the output signal calculated by the frequency calculating means is higher than the frequency set in advance, to perform any of the determination of the following (x) or (y) Detection device.
(X) When the extreme value stored in the peak storage means is the maximum of the repeated amplitude of the output signal, the inclination calculated by the inclination calculation means is stored, and the calculated inclination and the previous calculation are calculated. The following (x-1) or (x-2) is determined based on the rate of change from the slope.
(X-1) When the change is an increase and is greater than a preset change rate, it is determined that the detection target is approaching the sensor unit.
(X-2) When the change is a decrease and is smaller than a preset change rate, it is determined that the detection target is far away from the sensor unit.
(Y) When the extreme value stored in the peak storage means is the minimum of the repeated amplitude of the output signal, the inclination calculated by the inclination calculation means is stored, and the calculated inclination and the previous calculation are calculated. The following (y-1) or (y-2) is determined based on the rate of change from the slope.
(Y-1) When the change is decreasing and smaller than a preset change rate, it is determined that the detection object is approaching the sensor unit.
(Y-2) When the change is an increase and is larger than a preset change rate, it is determined that the detection target is far away from the sensor unit.   The urinal device provided with the object detection device according to claim 1, wherein the sensor unit is provided inside the urinal so as to be transmitted and received toward the human body, and preliminary cleaning is performed when the determination means determines that the human body is approaching. A urinal device comprising control means for performing the main cleaning when the human body moves away.

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