JP2013076581A - Human body detection apparatus and automatic faucet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic faucet device in which power consumption is reduced essentially.SOLUTION: In a faucet device, a reflection wave of a microwave transmitted to a predetermined detection area is received, a Doppler signal is generated based on the microwave transmitted to the predetermined detection area and the received reflection wave, and the presence of a human body in the predetermined detection area is detected based on the Doppler signal. The reflection wave is received and the Doppler signal is generated based on the reflection wave in each predetermined sampling cycle. The number of times of sampling until the Doppler signal becomes a peak value from a reference value is counted, and sampling after the peak value is stopped just the number of times corresponding to the counted number of times of sampling.

Description

  The present invention relates to a human body detection device and an automatic water faucet device, and more particularly, to a human body detection device and an automatic water faucet that detect the approach and separation of a human body or an object using a reflected wave of a propagation wave (for example, a radio wave such as a microwave). Relates to the device.

  There is an automatic faucet device that automatically detects the presence of an object and discharges water automatically as a faucet device that discharges water to a basin or a toilet. In this automatic faucet device, an infrared sensor is generally used for detecting an object, but in recent years, a radio wave sensor has also been used. The radio wave sensor can pass through the pottery and can conceal the sensor from the back surface or the inner surface of the pottery. Therefore, there is an advantage that the degree of freedom of sensor arrangement is improved. In addition, as a radio wave sensor, the Doppler sensor using radio waves, such as a microwave, is mentioned, for example.

  The Doppler sensor transmits a microwave and receives a reflected wave of the microwave, thereby detecting the position and distance of the object etc. reflecting the microwave, the movement of the object, etc. The microwave reflected by the object or the like is constituted by a standing wave signal when the object is stationary, and includes a standing wave signal and a Doppler signal when the object is moving. That is, if the reflected wave of the microwave is analyzed, the distance to the object can be detected based on the standing wave signal, and the movement of the object can be detected based on the Doppler signal.

  On the other hand, in recent years, a battery-driven water faucet device has also been developed in order to eliminate the need for external power supply from the viewpoint of improving installation properties. Some battery-operated faucet devices have a built-in generator that uses hydraulic power flowing through the faucet device to save power. Here, the Doppler sensor generally has higher power consumption than the infrared sensor. Therefore, when a Doppler sensor is used for a faucet device, a large-capacity battery is required, and when a Doppler sensor is used in a faucet device with a small battery capacity, power saving of the Doppler sensor is required.

  Here, Patent Document 1 discloses a technique for saving power in a Doppler sensor. The toilet bowl cleaning apparatus described in Patent Document 1 uses a Doppler sensor to detect an object such as a human body and perform automatic water discharge until the object enters a predetermined range with respect to the sensor. The object is detected based on the standing wave signal, and when the object falls within a predetermined range, the object is detected based on the Doppler signal. The detection of an object using a Doppler signal has higher detection accuracy than the detection of an object using a standing wave signal, and conversely, the detection of an object using a standing wave signal is more Doppler. This is because the amount of calculation is small and the power consumption is small compared to the detection of an object using a signal.

  Specifically, when detecting a Doppler signal from the received microwave, it is necessary to perform enormous calculation processing using multiple data such as digital filter calculation to extract the frequency component and magnitude of the Doppler signal. There is a large amount of power consumed by the arithmetic processing. For this reason, as in Patent Document 1, the object is detected based on the standing wave signal until the object falls within the predetermined range, and after the object falls within the predetermined range, the object based on the Doppler signal is detected. By performing detection, power consumption can be reduced.

JP 2008-31825 A

  In the technique of Patent Document 1 described above, the microwave Doppler sensor is controlled to intermittently operate at a predetermined cycle in order to reduce power consumption in the microwave Doppler sensor. However, the microwave Doppler sensor requires a certain time until it starts from the stop state. On the other hand, in order to detect the movement of the object based on the Doppler component, it is necessary to specify the frequency of the Doppler component.

  Based on the principle of DFT (Discrete Fourier Transform), it is possible to obtain spectral information in a frequency band up to half the sampling frequency. That is, in order to specify the frequency of the Doppler component, a sampling frequency that is at least twice as high as the frequency of the signal to be detected is required.

  Here, assuming that the Doppler signal for human body detection is 50 Hz or less, the time during which the microwave Doppler sensor can be intermittently turned off is 20 msec × (1/2) = 10 msec in principle. It is necessary to start the microwave Doppler sensor before the lapse of the off time by the start time of the microwave Doppler sensor. Therefore, even if the microwave Doppler sensor is operated intermittently, the off time of the microwave Doppler sensor is eroded by the start-up time, resulting in a reduction in the power consumption reduction effect of the microwave Doppler sensor.

  Of course, not only the microwave Doppler sensor, but also when using other radio wave sensors, as with the above-described microwave Doppler sensor, there is a problem of sampling frequency when specifying the frequency of the received radio wave, It was a factor that hindered the substantial reduction of electric power.

  The present invention has been made in view of the above problems, and an object thereof is to substantially reduce power consumption related to driving of a radio wave sensor included in a human body detection device.

  One aspect of the present invention receives a reflected wave of a propagation wave transmitted to a predetermined detection region, generates a Doppler signal based on the propagation wave transmitted to the predetermined detection region and the received reflected wave, A human body detection device for detecting the presence of a human body in the predetermined detection region based on a Doppler signal, wherein the reception of the reflected wave and generation of the Doppler signal based on the reflected wave are executed at predetermined sampling periods. The number of samplings until the Doppler signal reaches a first peak value from a predetermined value is counted, and the sampling after the first peak value is stopped by the number of times corresponding to the number of samplings.

In the said structure, the sampling performed in the vicinity of a peak value is performed, and a peak position can be specified based on the actually sampled data. Therefore, the frequency of the Doppler signal can be specified based on the peak position, and the accuracy of detecting the movement of the human body when the human body enters the predetermined detection area is not reduced.
On the other hand, sampling points that are not necessarily required to specify the peak position are omitted as much as possible. Propagation of transmitted waves, reception of reflected waves, and Doppler signals at timings corresponding to the omitted sampling points. Processing such as generation can be stopped.
Therefore, it is possible to reduce the power consumption of the human body detection device while maintaining the accuracy of motion detection.

  One of the selective aspects of the present invention is to count the number of samplings from the point where the Doppler signal crosses a predetermined reference value to the first peak value, and the number of times corresponding to the number of samplings, The sampling after the first peak value is stopped.

  In the above-described configuration, sampling is performed in about a quarter period thereafter based on the number of samplings in about a quarter period from the point where the Doppler signal crosses a predetermined reference value to the first peak value. The sampling point to stop is determined. In other words, the sampling point at which sampling is stopped is determined within a short cycle for each half wave, and the range in which sampling is stopped occurs only every quarter cycle. Therefore, since the intersection with the reference value and the peak value are always known, even if the Doppler signal fluctuates greatly, the sampling accuracy is unlikely to decrease, and the deterioration of the sampling accuracy is further prevented.

  One of the selective aspects of the present invention is that the Doppler signal counts the number of samplings from the second peak value appearing immediately before the first peak value to the first peak value, The sampling after the first peak value is stopped as many times as the number of samplings.

  In the above configuration, the Doppler signal is changed from the second peak value that appears immediately before the first peak value to the first peak value based on the number of samples in about ½ period thereafter. Sampling points at which sampling is stopped in about ½ cycle are determined. That is, a sampling point at which sampling is stopped is determined in a short cycle for each half wave, and the range in which sampling is stopped occurs every half cycle. Therefore, the accuracy is likely to be lower than in the case where the sampling stop range described above occurs every quarter period, but the amount of calculation can be reduced because the processing is simplified.

  One of the selective aspects of the present invention is configured to interpolate the sampling data missing due to the stop of the sampling using the sampling data before detecting the first peak value.

  In the above configuration, since sampling is stopped and data at sampling points where data is missing is interpolated, the frequency of the Doppler signal can be analyzed for each sampling period using a digital filter or the like, and the Doppler signal can be accurately analyzed. Can be specified.

  According to another aspect of the present invention, a reflected wave of a propagation wave transmitted to a predetermined detection region is received, a Doppler signal is generated based on the propagation wave transmitted to the predetermined detection region and the received reflected wave, and the Doppler signal is generated. An automatic water faucet device that detects the presence of an object in the predetermined detection region based on a signal, and performs reception of the reflected wave and generation of a Doppler signal based on the reflected wave at predetermined sampling periods. The number of samplings until the Doppler signal reaches a first peak value from a predetermined value is counted, and the sampling after the first peak value is stopped by the number of times corresponding to the number of samplings.

In the said structure, the sampling performed in the vicinity of a peak value is performed, and a peak position can be specified based on the actually sampled data. Therefore, the frequency of the Doppler signal can be specified based on the peak position, and the accuracy of detecting the movement of the object when the object enters the predetermined detection area is not reduced.
On the other hand, sampling points that are not necessarily required to specify the peak position are omitted as much as possible. Propagation of transmitted waves, reception of reflected waves, and Doppler signals at timings corresponding to the omitted sampling points. Processing such as generation can be stopped.
Therefore, it is possible to reduce the power consumption of the automatic water faucet device while maintaining the accuracy of motion detection.

  The human body detection device and the automatic faucet device described above include various modes such as being implemented in a state of being incorporated in another device or being implemented together with another method. In addition, the present technology corresponds to a human body detection system including the human body detection device and the automatic faucet device, a control method for the human body detection device and the automatic water faucet device having a process corresponding to the configuration of the device described above, and the configuration of the device described above. The present invention can also be realized as a human body detection program that causes a computer to realize the functions described above, a computer-readable recording medium that records the program, and the like.

  ADVANTAGE OF THE INVENTION According to this invention, the human body detection apparatus which can reduce the power consumption of a human body detection apparatus substantially can be provided, maintaining the precision of a motion detection.

It is the figure which showed the outline of the faucet device concerning this embodiment in section. It is a block diagram showing the composition of the faucet device concerning this embodiment. It is a figure explaining the outline | summary of the human body detection process in the case of not applying the human body detection process which concerns on this embodiment. It is a figure explaining the outline | summary of 1st Example of a human body detection process. It is a flowchart which concerns on 1st Example of a human body detection process. It is a figure explaining the outline | summary of 2nd Example of a human body detection process. It is a flowchart which concerns on 2nd Example of a human body detection process.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of the present embodiment:
(2) First example of human body detection processing:
(3) Second embodiment of human body detection processing:
(4) Summary:

(1) Configuration of the present embodiment:
<Outline configuration>
FIG. 1 is a cross-sectional view schematically illustrating a faucet device 1 according to the present embodiment, and FIG. 2 is a block diagram illustrating a configuration of the faucet device 1 according to the present embodiment. The faucet device 1 detects an object (such as a human body or an object) and automatically discharges water, and discharges water to a wash basin 2 provided in a washstand. In this embodiment, the faucet device 1 constitutes a human body detection device or an automatic faucet device.

  The basin 2 is provided on the upper surface of the basin counter 3. A water faucet 4 constituting a spout for discharging water to the ball surface 2 a of the basin 2 is provided on the basin counter 3. The faucet 4 has a water discharge port 4 a for discharging water, and is provided so that water discharged from the water discharge port 4 a is discharged into the ball surface 2 a of the basin 2.

  The water discharged from the faucet 4 a by the faucet 4 is supplied by the water supply channel 5. The water supply channel 5 guides water supplied from a water supply source such as a water pipe to the water outlet 4a. A drainage channel 6 is connected to the basin 2. The drainage channel 6 discharges water discharged from the water outlet 4a into the ball surface 2a of the basin 2.

  The faucet device 1 includes an electromagnetic valve 11, a microwave Doppler sensor 12, and a control unit 13. The electromagnetic valve 11 is provided in the water supply channel 5 and opens and closes the water supply channel 5. When the electromagnetic valve 11 is opened, the water supplied from the water supply channel 5 is discharged from the water outlet 4a. When the electromagnetic valve 11 is closed, the water supplied from the water supply channel 5 is not discharged from the water outlet 4a. It becomes a water state.

  The electromagnetic valve 11 is connected to the control unit 13, and the opening / closing operation of the electromagnetic valve 11 is controlled by the control unit 13. The solenoid valve 11 is electrically controlled according to a control signal from the control unit 13 to open and close the water supply channel 5. Thus, the electromagnetic valve 11 functions as a water supply valve that opens and closes the water supply path 5 of water discharged from the water discharge port 4a.

  The microwave Doppler sensor 12 detects an object that approaches the spout 4a. The water discharge destination of the water discharge port 4 a becomes a detection region of the microwave Doppler sensor 12. The microwave Doppler sensor 12 detects the position, movement, and the like of the object by transmitting the microwave and receiving the microwave reflected from the object such as a human body that has received the transmitted microwave.

  The microwave Doppler sensor 12 is provided inside the faucet 4 near the water outlet 4a, and is arranged to transmit microwaves toward the user side (left side in FIG. 1) of the washstand. The microwave Doppler sensor 12 is used to detect that a human body has approached the spout 4a, that a hand has been pushed out from the human body that has approached the spout 4a toward the spout 4a, and the like.

  The microwave Doppler sensor 12 is connected to the control unit 13. The control unit 13 receives a signal output from the microwave Doppler sensor 12 and detects the position and movement of the object based on this signal. In the present embodiment, the microwave Doppler sensor 12 using microwaves is employed as the Doppler sensor. However, for example, a Doppler sensor using ultrasonic waves or millimeter waves may be used. Further, the Doppler sensor may use not only microwaves but also radio waves of other frequencies as propagation waves, and light or the like as propagation waves.

  The controller 13 controls the opening / closing operation of the electromagnetic valve 11 based on a signal output from the microwave Doppler sensor 12. For this reason, the output signal from the microwave Doppler sensor 12 is input to the control unit 13 as described above. A control signal for the electromagnetic valve 11 is output from the control unit 13.

  As described above, the faucet device 1 of this embodiment includes the electromagnetic valve 11, the microwave Doppler sensor 12, and the control unit 13, and the control unit 13 uses the detection signal from the microwave Doppler sensor 12. By controlling the opening / closing operation of the electromagnetic valve 11, the detection of the object approaching the water discharge port 4a, that is, the human body detection, discharges water according to the movement of the user of the washstand. Hereinafter, the detail of each part of the faucet device 1 of this embodiment is demonstrated.

<Microwave Doppler sensor>
As illustrated in FIG. 2, the microwave Doppler sensor 12 includes an oscillation circuit unit 21, a transmission unit 22, a reception unit 23, and a mixing unit 24. The oscillation circuit unit 21 generates an electrical signal for obtaining a radio wave (microwave) transmitted by the microwave Doppler sensor 12. The oscillation circuit unit 21 generates a signal having a frequency of, for example, 10.525 GHz as an electrical signal, and outputs the signal as a transmission signal S1.

  The transmission unit 22 receives the transmission signal S1 output from the oscillation circuit unit 21, and transmits this transmission signal S1. For example, when the signal generated by the oscillation circuit unit 21 is a signal having a frequency of 10.525 GHz, the transmission unit 22 transmits a microwave of 10.525 GHz. The receiving unit 23 receives the reflected wave reflected by the object 10 to be detected by the microwave transmitted from the transmitting unit 22. The receiving unit 23 converts the received reflected wave (a radio wave including a microwave) into an electric signal and outputs it as a received signal S2. Note that the transmission unit 22 and the reception unit 23 have antennas for transmitting and receiving signals.

  The mixing unit 24 mixes (mixes) the transmission signal S1 output from the oscillation circuit unit 21 and the reception signal S2 output from the reception unit 23, and outputs the mixed signal as the sensor output S3. The sensor output S3 output from the mixing unit 24 is input to the control unit 13.

  The sensor output S3 includes a standing wave signal and a Doppler signal. The standing wave signal is used to detect the distance from the object 10, that is, the position of the object 10, and the Doppler signal is used to detect the movement of the object 10.

<Control unit>
Next, the control unit 13 will be described. As shown in FIG. 2, the control unit 13 includes a low-pass filter unit 31, an amplifier unit 32, a Doppler signal detection unit 33, a standing wave signal detection unit 34, an object detection unit 35, and a solenoid valve control unit. 36, a sensor control unit 37, and a storage unit 38. The object detection unit 35 includes a human body motion detection unit 39 and a human body position detection unit 40. The control unit 13 has a timer 41 for measuring time.

  The control unit 13 includes various functional parts such as a CPU (Central Processing Unit), a memory, and an input / output interface, and these various functional parts are connected to each other through a data communication bus or the like. The CPU included in the control unit 13 functions as a calculation unit that performs a predetermined calculation in accordance with a control program or the like stored in a ROM (Read Only Memory) that is one of the memories. The control unit 13 has at least an input interface for receiving an input signal from the microwave Doppler sensor 12 and an output interface for outputting a control signal for the electromagnetic valve 11 as an input / output interface.

<Generation of Doppler signal S6>
The low-pass filter unit 31 includes a low-pass filter unit 31 that removes a component of a microwave frequency band that is a frequency band of the transmission signal S1 and the reception signal S2 from the input signal. The low-pass filter unit 31 generates a signal S4 from which a component in the microwave frequency band is removed from the sensor output S3 input from the microwave Doppler sensor 12, and outputs the signal S4 to the amplifier unit 32.

  The amplifier unit 32 receives an input of the signal S4 output from the low-pass filter unit 31, generates an amplified signal S5 obtained by amplifying the input signal, and outputs the amplified signal S5 to the Doppler signal detection unit 33.

  The Doppler signal detection unit 33 receives the amplified signal S5 output from the amplifier unit 32. The Doppler signal detection unit 33 has a filter that removes a component of a frequency band unnecessary for human body detection from the frequency component of the input amplified signal S5. Remove band components. The frequency band unnecessary for human body detection is a frequency band exceeding 50 Hz, for example. The Doppler signal detection unit 33 outputs a signal obtained by removing a frequency band component unnecessary for human body detection from the amplified signal S5 as a human body detection Doppler signal S6.

  That is, the amplified signal S5 output from the amplifier unit 32 includes a DC component that is a standing wave signal and an AC component that is a Doppler signal, and removes components in a frequency band unnecessary for human body detection from the amplified signal S5. By doing so, a Doppler signal is extracted. More specifically, the Doppler signal detection unit 33 extracts the Doppler signal S6 by performing digital filter calculation or the like as software processing by a microcomputer or the like after the amplified signal S5 is converted into a digital signal by A / D conversion. .

  Here, the motion detection of an object (such as a human body) performed based on the Doppler signal S6 will be described. The following equation (1) is a basic equation relating to the Doppler frequency shift. The microwave Doppler sensor 12 detects the movement of the object by performing arithmetic processing based on the following equation (1).

Basic formula: ΔF = FS−Fb = 2 × FS × ν / c (1)
ΔF: Doppler frequency (frequency of Doppler signal included in sensor output S3)
FS: Transmission frequency (frequency of transmission signal S1)
Fb: reflection frequency (frequency of received signal S2)
ν: moving speed of detection object c: speed of light (300 × 10 ⁶ m / s)

  As shown in the above formula (1), the microwave of the transmission frequency FS transmitted from the transmission unit 22 is reflected by the object 10 moving at the speed ν. The reception unit 23 of the microwave Doppler sensor 12 receives the reflected wave from the object 10. The frequency of the reflected wave received by the receiving unit 23 undergoes a Doppler frequency shift due to relative motion, and has a reflection frequency Fb different from the transmission frequency FS.

  As described above, the low-pass filter unit 31 removes high-frequency components from the signal obtained by mixing the transmission signal S1 and the reception signal S2 in the mixing unit 24, thereby removing frequency components other than the Doppler frequency from the sensor output S3. The extracted signal is extracted. Then, a Doppler signal detection unit 33 extracts a component of a frequency band (for example, 50 Hz or less) for human body detection, and obtains a Doppler signal S6 for human body detection.

  The Doppler signal S6 output from the Doppler signal detection unit 33 is input to the human body motion detection unit 39 included in the object detection unit 35. Based on the input Doppler signal S6, the human body motion detection unit 39 detects from the movement of the object 10 that the object 10 has reached a position where it can receive water discharged from the spout 4a.

<Generation of standing wave signal S7>
On the other hand, the standing wave signal detector 34 also receives the amplified signal S5 output from the amplifier 32. The standing wave signal detector 34 detects a standing wave signal from the input amplified signal S5. As described above, the amplified signal S5 output from the amplifier unit 32 includes a DC component that is a standing wave signal and an AC component that is a Doppler signal. A standing wave signal is extracted from the amplified signal S5 by removing the Doppler signal component.

  Specifically, the standing wave signal detection unit 34 includes a low-pass filter circuit that functions as an AC component removal circuit. The standing wave signal detection unit 34 extracts the standing wave signal by removing the Doppler signal component from the amplified signal S5 using a low-pass filter circuit. That is, the standing wave signal detector 34 extracts and outputs the standing wave signal S7 by removing the AC component from the amplified signal S5 output from the amplifier 32.

  In the standing wave signal detection unit 34, signal processing for improving the accuracy of detecting the distance to the object 10 is appropriately employed. Specifically, for example, the following processing is performed.

  The standing wave signal is a signal that periodically changes so that the signal level (voltage level) decreases as the distance between the microwave Doppler sensor 12 and the object 10 increases. In the standing wave signal whose signal level periodically changes in this way, an abdomen having a large amplitude and a node having a small amplitude are alternately present every ½ cycle, so that the distance to the object 10 is sufficient. Detection accuracy may not be obtained. Here, the signal level of the standing wave signal corresponds to an amplitude value of a waveform that changes periodically.

  Therefore, the standing wave signal detection unit 34 first generates a signal whose phase is shifted from the standing wave signal obtained by the low-pass filter circuit as described above. Next, full-wave rectification is performed on each signal of the standing wave signal output from the low-pass filter circuit and the signal whose phase is shifted. Then, the signals subjected to full wave rectification are added to obtain a combined signal. The synthesized signal thus obtained is a signal having a signal level corresponding to the distance between the microwave Doppler sensor 12 and the object 10.

  By performing such signal processing, a signal whose level increases as the distance between the spout 4a of the faucet 4 where the microwave Doppler sensor 12 is disposed and the human body as the object 10 is closer is obtained as a composite signal. It is done. Thereby, the detection accuracy can be improved with respect to the distance to the object 10. In this signal processing, as the number of standing wave signals that are added and combined and have different phases from each other increases, the calculated combined signal becomes a smooth curve, and higher detection accuracy can be obtained.

  When performing such signal processing for improving the distance detection accuracy with respect to the object 10, the standing wave signal detection unit 34, for example, a phase shift circuit for shifting the phase of the standing wave signal, A full-wave rectifier circuit for performing full-wave rectification, an adder circuit for adding and synthesizing full-wave rectified signals, and the like.

  The standing wave signal S7 output from the standing wave signal detection unit 34 is input to the human body position detection unit 40 included in the object detection unit 35. Based on the input standing wave signal S7, the human body position detection unit 40 indicates that the target object 10 is within a predetermined range with respect to the spout 4a, or that the target object 10 has a predetermined value with respect to the spout 4a. Detects that it is out of range.

<Other controls>
The electromagnetic valve control unit 36 controls the opening / closing operation of the electromagnetic valve 11 based on the detection signal output from the object detection unit 35. Specifically, the electromagnetic valve control unit 36 discharges the target 10 from the spout 4a based on the Doppler signal S6 input from the Doppler signal detection unit 33 in the human body motion detection unit 39 of the target detection unit 35. When it is detected that the position has been reached to receive water, the electromagnetic valve 11 is opened.

  The sensor control unit 37 controls the operation of the microwave Doppler sensor 12. Control of the operation of the microwave Doppler sensor 12 by the sensor control unit 37 includes control of the sampling period of the microwave Doppler sensor 12.

  Here, the sampling period of the microwave Doppler sensor 12 (hereinafter simply referred to as “sampling period”) is an operation period when the microwave Doppler sensor 12 is intermittently operated at a predetermined period. For example, when the operation of the microwave Doppler sensor 12 is periodically performed at intervals of 2 msec, the sampling period is 2 msec. In this case, in the microwave Doppler sensor 12, a reflected wave is received from the object 10 by the receiving unit 23 every 2 msec, and a sensor output S3 is output.

  As the number of samplings increases, data can be detected with higher accuracy, but power consumption increases. Conversely, the smaller the number of samplings, the lower the data detection accuracy, but the lower the power consumption.

  The faucet device 1 of the present embodiment performs sampling at a relatively short cycle of 2 msec, performs sampling of sampling points that are indispensable for specifying the frequency of the Doppler signal, and samples sampling points that are not essential for specifying the frequency of the Doppler signal. Is supposed to stop. In this way, by performing sampling at a high cycle, the frequency identification accuracy is improved, and power consumption is reduced by not performing omissible sampling.

  The storage unit 38 stores a control program for the faucet device 1 and various data used for water discharge control in the faucet device 1 as described later. The storage unit 38 is configured by, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), or the like connected to the CPU.

(2) First example of human body detection processing:
FIG. 3 is a diagram illustrating an outline of the human body detection process when the human body detection process according to the present embodiment is not applied, and FIG. 4 illustrates an outline of the first example of the human body detection process according to the present embodiment. It is a figure to do. In these drawings, the timing at which the microwave Doppler sensor 12 performs sampling, that is, the sampling points are indicated by black circles.

<Conventional human body detection processing>
Note that the sampling performed by the microwave Doppler sensor 12 is controlled by the sensor control unit 37 included in the control unit 13 as described above. In addition, when the movement of the human body is detected, when the sampling is executed, the low-pass filter unit 31, the amplifier unit 32, the Doppler signal detection unit 33, and the human body movement detection unit 39 perform arithmetic processing, respectively. When the position is detected, when sampling is performed, the low-pass filter unit 31, the amplifier unit 32, the standing wave signal detection unit 34, and the human body position detection unit 40 respectively perform arithmetic processing.

  In the conventional human body detection process shown in FIG. 3, the sensor control unit 37 always causes the microwave Doppler sensor 12 to output the sensor output S3. And the control part 13 operates each part which concerns on a digital filter calculation with the sampling period of fixed time interval (DELTA) t, for example, and acquires the data corresponding to sampling points S0-S18 sequentially. If the time interval Δt is practically about 2 msec, the peak position of the Doppler signal can be specified with sufficient accuracy. If the time interval Δt is about 1 msec, the accuracy is further improved.

  The peak position is identified by analyzing the obtained sampling points S0 to S18. For example, a sampling point having an extreme value among the sampling points S0 to S18 can be set as the peak position. When the peak position is specified, the peak generation period, that is, the frequency of the Doppler signal is specified. Since the frequency of the Doppler signal reflects the movement of the user of the faucet device 1, the movement of the user of the faucet device 1 can be specified based on the frequency of the Doppler signal.

<Human Body Detection Process of First Embodiment>
In the human body detection processing according to the present embodiment, at least at the sampling point in the vicinity of the peak of the Doppler signal, it is actually sampled from the Doppler signal generated based on the actually transmitted / received radio wave, and at other sampling points, Interpolation calculation is used as appropriate. That is, the other sampling points include sampling points for actual sampling and sampling points for generating data by interpolation calculation. As a result, the number of samplings is reduced, the number of executions of arithmetic processing related to sampling is reduced, and an increase in power consumption is suppressed.

  Hereinafter, a specific description will be given with reference to FIG. In FIG. 4, for example, there is a peak between sampling points S6 and S7, and there are sampling points S3 to S6 on one side, and sampling points S7 to S10 on the other side across this peak.

  Here, sampling points S6, S7, and S8 near the peak value are indispensable for specifying the frequency of the Doppler signal, and data is actually sampled from the Doppler signal generated based on the actually transmitted / received radio wave. Need to get. However, the sampling points S3 and S4 on one side of the peak are on the other side of the same peak although data is actually obtained by sampling from the Doppler signal generated based on the actually transmitted / received radio wave. Sampling points S9 and S10 are not sampled and data is missing.

  The data at the sampling point where this data is missing may be omitted as long as the frequency and amplitude are detected based on the peak position, but continuous data is required when performing a digital filter, etc. Needs to be interpolated in some way.

  As an interpolation method, for example, there are a method of interpolation using sampling data before detecting a peak value, a method of approximation with a linear function, a method of approximation with a trigonometric function, and the like. Of course, it is possible to approximate using a function of second order or higher. Hereinafter, each interpolation method will be described.

<Interpolate with data before peak value detection>
When interpolation is performed using sampling data before the peak value is detected, various methods can be employed. Therefore, a few specific methods will be described below taking the case shown in FIG. 4 as an example.

  First, sampling data obtained at a sampling point S8 next to the sampling point S7 detected as a peak value is used as a reference, and sampling is performed before the sampling point S7 detected as a peak value. The sampling data obtained at the several sampling points S6, S5, S4, and S3 are sequentially compared, and the sampling point having the sampling data closest to the sampling point S8 is searched.

  Specifically, the sampling data of the sampling point S8 and the sampling point S6, the sampling point S8 and the sampling point S5, the sampling point S8 and the sampling point S4, and the sampling point S8 and the sampling point S3 are sequentially compared. At this time, the sampling point S5 and the sampling point S8 are the closest.

  Since the sampling data is known to gradually increase in the order of sampling points, the sampling point S5 is closer to the sampling data at the sampling point S8 than the sampling point S6, and the sampling point is compared to the sampling point S4. When it is found that S5 is closer to the sampling data, it may be determined that the closest approximation is the sampling point S5, and the comparison may be terminated.

  When the most approximate sampling point is found in this way, the sampling data of the acquired sampling points S4 and S3 in order from the peak as shown by arrows in FIG. 4 with the sampling point S8 and the sampling point S5 as the base points. The data of the missing sampling points S9 and S10 are sequentially interpolated.

  The second is a method of interpolating with sampling data of a sampling point that is closest to the symmetrical position of the sampling point to be interpolated with reference to the true peak position. The true peak position used here is obtained by, for example, digital filter calculation, or by searching for an intersection with the nearest reference value on the left and right of the sampling point detected as the peak value, and using the midpoint of these intersections as the peak value. Can be.

  Specifically, there is a true peak value between the sampling point S6 and the sampling point S7. Therefore, as shown by an arrow in FIG. 4, the sampling point S9 is interpolated at the sampling point S4 closest to the symmetric position with the peak value as the center, and similarly, the sampling point closest to the symmetric position with the peak value as the center. In S3, the sampling point S10 is interpolated.

  The third is a method of interpolating with sampling data of sampling points at symmetrical positions around the sampling point S7 detected as a peak value. In this method, the greater the deviation between the sampling point detected as the peak value and the true peak position, the more inaccurate, but the interpolation process can be performed at high speed.

  Specifically, when the sampling data at the sampling point S9 is interpolated, the sampling point S9 is separated from the sampling point S7 by two to the right, so the data at the sampling point S5 that is two to the left from the sampling point S7 is used. Interpolate. Similarly, when the sampling data at the sampling point S10 is interpolated, since the sampling point S10 is three distances to the right from the sampling point S7, interpolation is performed with the data of the sampling point S4 three points to the left from the sampling point S7. .

<Interpolation by linear function>
When interpolation is performed using a linear function, an approximate calculation is performed on a Doppler signal in a range that is not actually measured based on sampling data at several points before and after the interpolation range. The value corresponding to the sampling point is interpolated to the data of the sampling point where data is lost due to the stop of sampling.

<Interpolation using trigonometric functions>
When interpolating using a trigonometric function, as in the case of a linear function, an approximate calculation is performed on a Doppler signal in an unmeasured range based on sampling data at several points before and after the interpolation range. The value on the approximate curve and corresponding to the sampling point is interpolated to the data of the sampling point where data is lost due to the stop of sampling.

  An appropriate trigonometric function may be selected in accordance with the frequency fluctuation state of the Doppler signal. As the Doppler signal approaches, the speed of walking decreases as the user approaches, so the frequency tends to gradually decrease. Therefore, the frequency of the Doppler signal is stored in the storage unit 38 or the like, and a trigonometric function corresponding to the frequency fluctuation tendency is appropriately selected and used for the approximate calculation. The frequency of the Doppler signal may be obtained based on the peak position, or may be obtained by digital filter calculation or the like, as will be described in each embodiment described later.

  Specifically, when the frequency of a recent Doppler signal varies, for example, from 20 Hz to 15 Hz to 10 Hz, it can be predicted that it will be 5 Hz in the next cycle. Therefore, by using F (t) = A · sin (2π · 5t) as a trigonometric function used for the approximate calculation, a more accurate approximation result can be obtained.

<Description of flowchart>
FIG. 5 is a flowchart according to the first embodiment of the human body detection process. It is assumed that the processing shown in the figure is repeatedly executed periodically by the control unit 13 at a predetermined sampling period while the faucet device 1 is powered on. More specifically, for example, the process shown in FIG. 5 is periodically repeated every 1 msec or 2 msec.

  When the process is started, the control unit 13 increases the count value C of the counter for counting the number of samplings by 1 (S100). Specifically, it increases by 1 every time sampling (S120) described later is executed. This counter is used for calculating the number of sampling pauses (hereinafter referred to as the sampling pause number) and determining whether the number of sampling pauses has reached the sampling pause number.

  This counter is cleared when the Doppler signal crosses the reference value (S270: Yes) (S280). During the top detection described later, the number of samples up to the first sampling point after exceeding the next peak of the Doppler signal is counted by the counter. During the bottom detection described later, after the bottom of the Doppler signal is exceeded. The number of samples up to the first sampling point is counted by the counter.

  The count value thus counted corresponds to a value obtained by adding 1 to the number of sampling points from the reference point to the top or the number of sampling points from the reference point to the bottom. However, in consideration of the error of the peak detection timing, it can be considered to correspond to a value obtained by adding 2 to the number of sampling points.

  Further, the counter is cleared (S200, S250) when a pause count calculation process described later is completed (S180, S230). Therefore, the count value C counted up thereafter is a value corresponding to the number of samplings during the sampling pause. The count value C is a value that substantially matches the number of samplings from the end of the pause count calculation process to the detection of the next reference value.

  If the value of the counter is incremented by 1 (S100), the control unit 13 next determines whether the sampling is paused (S110). In the present embodiment, this determination is made based on whether a sampling pause flag (to be described later) is set in the storage unit 38. If the sampling pause flag is not set (S110: No), it is determined that sampling is not paused, and sampling is executed (S120).

Here, the operation of the faucet device 1 when sampling is executed will be described.
In the present embodiment, as described above, the microwave Doppler sensor 12 is always activated, but transmission of microwaves and reception of radio waves are stopped except when sampling is executed, and the control unit 13 Also, the operation of each part related to the digital filter calculation is stopped.

  If it is determined that sampling is not paused, the sensor control unit 37 controls the microwave Doppler sensor 12 to transmit microwaves and receive radio waves for a time corresponding to the sampling period, and to output sensor output S3. Is output. Furthermore, based on this sensor output S3, the detection of the human body motion and the detection of the human body position are executed. Therefore, power consumption related to the digital filter calculation can be suppressed except when sampling is actually executed.

  When the sampling process is completed (S120), the data interpolation process (S130 to S150) is executed next. In the data interpolation process, it is first determined whether data interpolation is necessary (S130). Specifically, after sampling is stopped, if sampling is first performed in step S120, it is determined that data interpolation is necessary (S130: Yes), and in other cases, it is determined that data interpolation is not required (S130: No).

  In this embodiment, the necessity of data interpolation is determined based on the interpolation flag set in the storage unit 38. If the interpolation flag is set, it is determined that data interpolation is necessary (S130: If the interpolation flag is not set, it is determined that data interpolation is not required (S130: No).

  This interpolation flag is set when the number of samplings corresponding to the number of sampling pauses is stopped (S290) (S310), and is cleared when data interpolation is completed (S140) (S150). Data interpolation can be performed by the various interpolation methods described above.

  When the data interpolation process is completed or skipped (S150, S130: No), it is determined whether the peak of the next Doppler signal is top or bottom (S160). In this determination, if the peak detected immediately before is the top, the next peak is determined to be the bottom (S160: bottom detection), and if the peak detected immediately before is the bottom, the next peak The peak at is determined to be the top (S160: Top detection).

  In the present embodiment, when a peak is detected immediately before, a setting value indicating a peak opposite to the detected peak type is stored in the storage unit 38, and the determination in step S160 is performed by the storage unit 38. This is performed based on the set value stored in.

  If the top detection is set (S160: Top detection), it is determined whether the value sampled in step S120 is smaller than the previously sampled value (S170). Here, since the sampling value before passing the next top is increased from the immediately preceding sampling value (S170: No), the process proceeds to step S270.

  On the other hand, since the first sampling value after passing the top is smaller than the immediately preceding sampling value (S170: Yes), the process proceeds to step S180. That is, it can be determined by a simple comparison operation whether or not it is the first sampling point after passing the top.

  In the first embodiment, since the number of samples from the reference value to the peak is detected, the sampling points counted from the peak to the next peak include the sampling points from the first peak to the reference value. End up.

  Therefore, if the intersection with the reference value is detected while the data is gradually increasing (S170: No) (S270: Yes), the count value C is once cleared (S280). With this process, the number of samplings from the reference value to the peak can be accurately detected.

  In step S180, a pause count number D is calculated based on the count value C. Specifically, first, the count value C is stored in the storage unit 38. Hereinafter, the count value stored in the storage unit 38 at this time is referred to as a “pause count base value”.

  Next, 1 is subtracted from the pause count base value as a value corresponding to the number of times of sampling sampled beyond the peak. Next, a predetermined number is subtracted from the pause count base value in consideration of an error from the number of sampling points arranged symmetrically across the peak. In this embodiment, this error is set to 1 or 2.

  The value obtained by subtracting 1 and the error equivalent number from the pause count base value in this way is hereinafter referred to as a pause count number D. When the pause count number D is calculated in this way, the pause flag is set in the storage unit 38 (S190), the counter is cleared (S200), and the setting value stored in the storage unit 38 is changed to bottom detection. (S210), and the process ends.

  In the present embodiment, when calculating the pause count number D, the numerical value is changed in consideration of only the error, but the pause count number D may be adjusted according to the amplitude fluctuation state of the Doppler signal. For example, while the user is approaching, the amplitude of the Doppler signal gradually increases. Accordingly, the amplitude of the Doppler signal is stored in the storage unit 38 or the like, and the pause count number D is increased if the amplitude tends to increase by multiplying the pause count number D by a coefficient corresponding to the fluctuation tendency of the amplitude. If the amplitude tends to decrease, a correction for decreasing the pause count number D is added. By performing such correction, a pause count number D optimized to the number of sampling points at which sampling can actually be paused can be obtained, and more accurate reduction of power consumption and maintenance of human body detection accuracy can be achieved. can do.

  On the other hand, if bottom detection is set (S160: bottom detection), it is determined whether the value sampled in step S120 is increased as compared to the previously sampled value (S220). Here, since the sampling value before passing the next bottom is smaller than the immediately preceding sampling value (S220: No), the process proceeds to step S270.

  On the other hand, since the first sampling value after passing the bottom increases from the immediately preceding sampling value (S220: Yes), the process proceeds to step S230. That is, it can be determined by a simple comparison operation whether it is the first sampling point after passing through the bottom.

  The process when the intersection with the reference value is detected while the data is gradually decreasing (S220: No) (S270: Yes) is the same as the case of the top detection described above, and the counter is once cleared (S280). With this process, the number of samplings from the reference value to the peak can be accurately detected.

  In step S230, the number of sampling pauses is calculated based on the count value C. The calculation of the pause count number D is the same as in the case of the top detection described above, and the pause count base value is stored in the storage unit 38, which corresponds to the number of samplings sampled beyond the peak from the pause count base value. 1 is subtracted as a value, and a predetermined number is subtracted from the rest count base value in consideration of an error from the number of symmetrically arranged sampling points across the peak.

  When the pause count number D is calculated in this way, the pause flag is set in the storage unit 38 (S240), the counter is cleared (S250), and the setting value stored in the storage unit 38 is changed to top detection. (S260), and the process ends.

Next, processing during sampling suspension will be described.
This process is executed when it is determined in step S110 that the sampling is paused. In this embodiment, this process is executed when the sampling pause flag is stored in the storage unit 38.

  First, in step S290, the count value C is compared with the pause count number D. If the count value C is equal to the pause count number D, it is determined that the sampling pause count has reached the pause count number D (S290: Yes), the pause flag is cleared (S300), and the interpolation flag is set (S310). ), The process is terminated. Therefore, sampling can be paused an appropriate number of times.

  On the other hand, if the count value C and the pause count number D are different, it is determined that the number of sampling pauses has not reached the pause count number D (S290: No), and the process is terminated.

(3) Second embodiment of human body detection processing:
FIG. 6 is a diagram illustrating an outline of a second example of the human body detection process according to the present embodiment. In the figure, the timing at which the microwave Doppler sensor 12 performs sampling, that is, the sampling points are indicated by black circles. In the second embodiment, as shown in FIG. 6, at least a part of sampling from the next peak value to the next peak value is stopped based on the number of samplings from the peak value to the next peak value. .

  In FIG. 6, for example, there is a peak between sampling points S6 and S7, and there are sampling points S1 to S6 on one side and sampling points S7 to S12 on the other side across this peak.

  Here, the sampling points S6, S7, and S8 near the peak position are indispensable for specifying the frequency of the Doppler signal, and data is actually sampled from the Doppler signal generated based on the actually transmitted / received radio wave. Need to get. However, the sampling points S1 to S5 on one side of one peak are actually sampled from the Doppler signal generated based on the actually transmitted / received radio wave, but the other side of the same peak is obtained. Sampling points S9 to S12 are not sampled and data is missing.

  The sampling point data lacking this data may be omitted as long as the frequency and amplitude are detected based on the peak position as in the first embodiment, but a digital filter or the like is used. When continuous data is necessary, it is necessary to interpolate by some method. As an interpolation method, interpolation can be performed by the same method as in the first embodiment described above.

<Description of flowchart>
FIG. 7 is a flowchart according to the second embodiment of the human body detection process. It is assumed that the processing shown in the figure is repeatedly executed periodically by the control unit 13 at a predetermined sampling period while the faucet device 1 is powered on. More specifically, for example, the process shown in FIG. 7 is periodically repeated every 1 msec or 2 msec.

  Note that the process shown in FIG. 7 is largely in common with the process shown in FIG. 5, and specifically, steps S100 to S160 and S290 to S310 shown in FIG. 5 and steps S400 to S460 and S550 shown in FIG. ~ S570 are common to each other, and therefore only the parts of the different processing will be described below.

  First, in the second embodiment, since the processing corresponding to steps S270 to S280 of the first embodiment is not performed, the count value C of the counter is not cleared even if it intersects with the reference value. Therefore, the count value C counted up during the top detection is the sampling point immediately after the next detected top from the sampling point next to the sampling point immediately after the bottom detected immediately before. This corresponds to the number of sampling points up to the next sampling point. However, if there is an error in peak detection timing, an error of about 1 or 2 may occur.

  Thus, since the counter value C is not cleared at the time of crossing the reference value, if the sampling value is increased from the immediately preceding sampling value in the determination branch of step S470 (S470: No), the processing is performed as it is. Exit. Similarly, in the determination branch of step S520, when the sampling value is smaller than the immediately preceding sampling value (S520: No), the processing is ended as it is.

  Next, in the pause count number calculation process executed in step S480, the pause count number D is calculated by subtracting 1 and the error from the pause count base value, as in step S180 shown in the first embodiment. Since the calculation is based on the count value C that is not cleared at the time of the intersection with the value, the value is larger than the pause count number D calculated in the first embodiment.

  Next, since the second embodiment is configured to pause sampling during bottom detection based on the number of sampling points during top detection, even if an increase in data value is detected during bottom detection (S520). : Yes), the pause count number calculation process and the pause flag are not set, the count value C is cleared (S530), and only the process of changing the setting to top detection (S540) is executed and the process is terminated.

  According to the human body detection process according to the second embodiment described above, since the peak position is reliably measured, the frequency detection accuracy of the Doppler signal is maintained at a certain level or more, but according to the first embodiment described above. Compared to the human body detection process, there is a possibility that the accuracy is slightly lower than the frequency detection accuracy. However, since the number of sampling points to stop sampling increases compared to the first embodiment, the calculation processing load decreases, and the power consumption may decrease compared to the human body detection processing according to the first embodiment. is there.

(4) Summary:
According to the embodiment described above, the reflected wave of the microwave transmitted to the predetermined detection region is received, the Doppler signal is generated based on the microwave transmitted to the predetermined detection region and the received reflected wave, and the Doppler signal is generated. The faucet device 1 detects the presence of a human body in the predetermined detection area based on the received wave, and receives the reflected wave and generates a Doppler signal based on the reflected wave at predetermined sampling periods. Thus, it is possible to provide the faucet device 1 that counts the number of samplings until the Doppler signal reaches the peak value from the reference value, and stops sampling after the peak value by the number of times corresponding to the number of samplings. In this faucet device 1, the power consumption can be substantially reduced without lowering the detection accuracy of the frequency of the Doppler signal compared to the conventional faucet device 1.

  In the first embodiment described above, during the top detection after crossing the reference value, sampling is actually performed to acquire data, and during the bottom detection before crossing the reference value, the sampling is stopped. It was done, but it is not limited to this. For example, during bottom detection after crossing the reference value, sampling may be actually performed to acquire data, and sampling may be stopped during top detection before crossing the reference value.

  In the second embodiment described above, sampling is actually executed during top detection to acquire data, and sampling is stopped during bottom detection. However, the present invention is not limited to this. For example, sampling may be actually performed during bottom detection to acquire data, and sampling may be stopped during top detection.

  Note that the present technology is not limited to the above-described embodiments, and the configurations disclosed in the above-described embodiments are replaced with each other or the combination thereof is changed, disclosed in the known technology, and in the above-described embodiments. A configuration in which each configuration is mutually replaced or a combination is changed is also included. Further, the technical scope of the present invention is not limited to the above-described embodiments, but extends to the matters described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Faucet device, 2 ... Basin, 2a ... Ball surface, 3 ... Wash counter, 4 ... Faucet, 4a ... Water outlet, 5 ... Water supply channel, 6 ... Drainage channel, 10 ... Object, 11 ... Solenoid valve , 12 ... Microwave Doppler sensor, 13 ... Control part, 21 ... Oscillator circuit part, 22 ... Transmitter part, 23 ... Receiver part, 24 ... Mixing part, 31 ... Low pass filter part, 32 ... Amplifier part, 33 ... Doppler signal detection 34, standing wave signal detection unit, 35 ... object detection unit, 36 ... solenoid valve control unit, 37 ... sensor control unit, 38 ... storage unit, 39 ... human body motion detection unit, 40 ... human body position detection unit, 41 ... Timer, D ... Pause count

Claims (5)

A reflected wave of a propagation wave transmitted to a predetermined detection region is received, a Doppler signal is generated based on the propagation wave transmitted to the predetermined detection region and the received reflected wave, and the predetermined detection region is based on the Doppler signal A human body detection device for detecting the presence of a human body in
The reception of the reflected wave and the generation of a Doppler signal based on the reflected wave are executed every predetermined sampling period,
The human body detection characterized in that the number of samplings until the Doppler signal reaches a first peak value from a predetermined value is counted, and the sampling after the first peak value is stopped as many times as the number of samplings. apparatus.   The number of samplings from the point at which the Doppler signal crosses a predetermined reference value to the first peak value is counted, and sampling after the first peak value is stopped as many times as the number of samplings. The human body detection device according to claim 1.   The Doppler signal counts the number of samplings from the second peak value that appears immediately before the first peak value until the Doppler signal reaches the first peak value, and the first number of times corresponding to the number of samplings. The human body detection device according to claim 1, wherein sampling after the peak value is stopped.   The human body detection device according to any one of claims 1 to 3, wherein the sampling data missing due to the stop of the sampling is interpolated using the sampling data before the first peak value is detected. A reflected wave of a propagation wave transmitted to a predetermined detection region is received, a Doppler signal is generated based on the propagation wave transmitted to the predetermined detection region and the received reflected wave, and the predetermined detection region is based on the Doppler signal An automatic faucet device that detects the presence of an object in
The reception of the reflected wave and the generation of a Doppler signal based on the reflected wave are executed every predetermined sampling period,
The automatic water that counts the number of samplings until the Doppler signal reaches a first peak value from a predetermined value, and stops sampling after the first peak value by the number of times corresponding to the number of samplings. Stopper device.

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