JP2012211447A - Water discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water discharge device for suppressing power consumption when using a Doppler sensor for detecting an object, and for achieving a noise resistance and a high reaction rate.SOLUTION: The water discharge device comprises: a discharge part; a sensor part 7 using reflected waves from radiated electric waves for acquiring information about the movement of a detected body; and a control part 9 for controlling water discharge from the discharge part, based on a detection signal from the sensor part 7. The control part 9 comprises: standing wave detecting means 22 for detecting standing waves included in the detection signal from the sensor part 7; and frequency component detecting means 23 for performing digital filter processing to detect frequency components included in the detection signal from the sensor part 7. The control part 9 varies an operation method for the digital filter processing depending on an output value for the standing wave detecting means 22, when detecting the frequency components included in the output of the sensor part 7.

Description

  The present invention relates to a water discharge device that controls water discharge using a radio wave sensor using a microwave or the like provided in a hand washing place, a toilet, a kitchen, or the like.

  A toilet cleaning device that detects a human body or urine flow using a Doppler sensor such as a microwave Doppler sensor and cleans the inside of the toilet is known (for example, see Patent Document 1). The microwave Doppler sensor detects movement of an object by transmitting microwaves and receiving microwaves reflected by the object.

  That is, the microwave Doppler sensor obtains a Doppler signal from a difference signal between the frequency of the microwave transmitted from the sensor and the frequency of the signal received by the sensor when the microwave transmitted from the sensor is reflected by an object such as a human body. Generate.

  The Doppler signal is a signal representing the movement of the object (for example, the approach of the object or the separation of the object), and the control unit of the water discharge device determines the movement of the object from the Doppler signal, thereby sanitary ware. Water supply control is performed.

  In addition, the frequency component contained in the Doppler signal and the standing wave signal are used to detect the object, while standing by, the standing wave with a light processing load is detected, and after the standing wave is detected, the processing load is heavy. Had gone. (For example, refer to Patent Document 2).

  The standing wave signal refers to a signal that changes according to the distance from the sensor to the object. The standing wave signal increases when the distance to the object is short, and the standing wave signal decreases when the distance from the object is long.

Japanese Utility Model Publication 2-69760 JP2008-31825A

  In order to detect the movement of the object, it is necessary to perform processing for extracting the frequency component and the magnitude of the Doppler signal. In addition, since the time at which an object such as a human body approaches or separates is not constant, the Doppler sensor must be operated at all times. That is, in order to appropriately detect the movement of the object, the Doppler sensor is always in an operating state in the conventional water discharge device.

  For this reason, power for operating the Doppler sensor and power for Doppler signal processing have always been consumed. In general, many water discharge devices are battery-driven, and thus a battery having a large capacity has to be used by constantly performing the operation of the Doppler sensor and processing of the Doppler signal.

  The method of detecting an object by detecting a standing wave signal has a light processing load but low noise resistance, and may cause a false detection. On the other hand, it is not practical from the viewpoint of low consumption to always perform digital filter processing in order to extract a necessary frequency component from the Doppler signal. In addition, since digital filter processing uses delay data, there is a problem that a delay occurs before an output result is generated.

  Therefore, an object of the present invention is to provide a water discharge device that suppresses power consumption, makes noise resistant, and has a fast reaction speed even when an object is detected by a Doppler sensor.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a water discharge unit, a water discharge unit, a sensor unit that acquires information related to the movement of the detected object by the reflected wave of the radiated radio wave, A control unit that controls water discharge from the water discharge unit based on the detection signal of, the control unit, standing wave detection means for detecting a standing wave included in the detection signal from the sensor unit, Frequency component detection means for performing digital filter processing for detecting a frequency component included in the detection signal from the sensor section, and the control section performs the digital filter processing according to an output value of the standing wave detection means. The frequency component detection means detects the frequency component included in the output of the sensor unit using the variable calculation method, and provides a water discharging device.

  Usually, the time during which the water discharge device is unused in the day is dominant, and by adopting such a configuration, the digital filter processing calculation method when the water discharge device is unused is a light calculation processing method. By changing to, the power consumption of the water discharger can be suppressed.

  According to a second aspect of the present invention, in the water discharge device according to the first aspect, the control unit includes a first signal amplified by an amplifier to detect the approach of the user and the presence of the user. In order to detect, a second signal amplified by a gain smaller than the amplifier used in the first signal or not amplified at all is input, and the control unit detects a standing wave included in the first signal. Standing wave detection means, frequency component detection means for performing digital filter processing for detecting frequency components contained in the first signal, and second standing for detecting standing waves contained in the second signal A water discharge device comprising: a wave detection unit, wherein the control unit operates the second standing wave detection unit according to output results of the standing wave detection unit and the frequency component detection unit. provide.

  By adopting such a configuration, it is possible to quickly detect an object while preventing erroneous detection of the object.

It is the schematic of a water discharging apparatus. 2 is a detailed schematic diagram of a microwave Doppler sensor and a control unit in Embodiment 1. FIG. It is a block diagram of a FIR filter. It is a wave form diagram of Sig4 when the output value of a standing wave detection means is small. It is a wave form diagram of Sig4 when the output value of a standing wave detection means is a little large. It is a wave form diagram of Sig4 when the output value of a standing wave detection means is large. It is a flowchart of the calculation method change of the digital filter process in a 1st Example. It is a detailed schematic diagram of a microwave Doppler sensor and a control unit in the second embodiment. It is the flowchart explaining the target object detection method in a 2nd Example.

  Embodiments of an automatic faucet device according to the present invention will be described below in detail with reference to the drawings.

(First embodiment)
As shown in FIG. 1, a water discharge device 1 according to this embodiment includes a wash basin 2, a water discharge portion 3 for discharging water into a bowl of the wash basin 2, and a bowl surface of the wash basin 2 provided in the middle of a water supply path 4. A water supply valve 5 for discharging water into and out of the water, a drainage channel 6 for draining water discharged into the bowl of the basin 2, a microwave Doppler sensor 7 for generating a Doppler signal, and the microwave Doppler sensor 7 The object 8 (usually a human body) is detected on the basis of the Doppler signal output from, and the water supply valve 5 is controlled in accordance with the detection result to stop water discharge into the bowl of the basin 1 and stop the water discharge. And a control unit 9 for controlling. The water supply valve 4 is composed of an electromagnetic valve or the like.

  The microwave Doppler sensor 7 is disposed in the water discharger 3 as shown in FIG. 1, and radiates and transmits a radio wave forward, and receives a reflected wave of the radio wave to detect a human body as an object. The Doppler signal for generating the signal is generated, and specifically, as shown in FIG. The microwave Doppler sensor 7 detects the movement of the object from the relationship of the following formula (1).

Basic formula: ΔF = FS−Fb = 2 × FS × ν / c (1)
ΔF: Doppler frequency (frequency of Doppler signal Sig3)
FS: Transmission frequency (frequency of transmission signal Sig1)
Fb: reflection frequency (frequency of received signal Sig2)
ν: object moving speed c: speed of light (300 × 10 ^ 6 m / s)

  FIG. 2 is a detailed configuration diagram of the microwave Doppler sensor and the control unit. An oscillation circuit 10 that generates a transmission signal Sig1 that is an electrical signal of 10.525 GHz, a transmission unit 11 that transmits a transmission signal Sig1 output from the oscillation circuit 10 as a microwave of 10.525 GHz, and a transmission unit 11 The microwave is reflected by the object, the receiving means 12 that receives the reflected wave and outputs the received signal Sig2 converted into an electric signal, and the transmission signal Sig1 and the received signal Sig2 are mixed (mixed) to obtain Sig3. The high-frequency component is removed by the low-pass filter unit 21 and the Doppler frequency ΔF (Sig4) is extracted from the sensor output Sig3.

  In the control unit 9, Sig 4 is input to the standing wave detection means 22. The standing wave detecting means 22 determines how much the Sig4 value is different from the reference value. This difference becomes an output value from the standing wave detection means 22. The output value of the standing wave detection means 22 increases when the distance to the object is short, and the output value of the standing wave detection means 22 decreases when the distance from the object is long. The setting of the reference value is convenient for detecting the Doppler signal without distortion in a waveform whose polarity is the object if the output is assumed to be an intermediate value of the microwave Doppler sensor. For example, if the output of the microwave Doppler sensor is 0 to 5, the reference value is 2.5.

  Further, the control unit 9 has a frequency component detection means 23 for extracting a necessary frequency component when detecting the object 8 from the Sig 4. Specific processing for detecting the frequency component includes digital filter processing. FIG. 3 shows a configuration diagram of an FIR filter which is one of digital filter processes.

  A delay element 31 and a filter coefficient 32 for the input signal are provided, and an output which is a necessary frequency component is obtained by multiply-adding each delayed input signal and the filter coefficient. The presence / absence of the object is determined by the object detection determining means 24 in accordance with the output value. The product-sum operation method is changed by the operation method variable means 25 according to the output value of the standing wave detection means 22. Details for changing the calculation method are described below.

A case where there are four input signals (n = 3) will be described as an example. At this time, the arithmetic expression of the FIR filter can be expressed as Expression (2), and a multiplication operation with a heavy processing load is performed four times.
y (3) = h0 · X (0) + h1 · X (1) + h2 · X (2) + h3 · X (3) (2)

FIG. 4 shows an example of the Sig4 waveform when the object 8 does not exist and the output value of the standing wave detecting means is small. In this embodiment, the portion having the largest waveform amplitude value is adopted as the output value V1 from the standing wave detecting means 22. This may be the maximum value of each input data or an average value of a certain number of input data. At this time, the input data can be approximated as X (0) = X (1) = X (2) = X (3), and Expression (2) can be expressed as Expression (2) ′, A multiplication operation with a heavy processing load can be completed in one time.
y (3) = (h0 + h1 + h2 + h3) .X (0) (2) ′

  In general, since the time zone in which the water discharge device is not used in the day (the time zone in which the object 8 does not exist) is dominant, the low consumption effect due to the reduction of the multiplication operation processing is very large. Further, since the number of multiplication operations is only one regardless of the number of data of the input signal, the effect increases as the number of data of the input signal increases.

As shown in FIG. 5, in the Sig4 waveform when the output value of the standing wave detection means 22 is slightly large, it can be approximated as X (0) = X (1), X (2) = X (3), Expression (2) can be expressed as Expression (2) ″, and the processing load of the multiplication operation can be reduced as compared with Expression (2).
y (3) = (h0 + h1) .X (0) + (h2 + h3) .X (2) (2) ''

  In the above example, a low pass filter is obtained by calculating the average of data for two times. Therefore, instead of calculating the filter coefficient as (h0 + h1), a filter coefficient for reducing the number of samplings is prepared in advance. You may calculate using a coefficient. For example, in the case of 2 ms period sampling, averaging twice is equivalent to 4 ms period sampling, so a digital filter coefficient for 4 ms sampling is prepared separately. Since the effect of the low-pass filter is obtained by averaging twice, the cut-off frequency is less than that in the case of 2 ms period sampling, and a further low consumption effect is obtained.

  As shown in FIG. 6, since the input data cannot be approximated with the Sig4 waveform when the output value of the standing wave detecting means 22 is large, the calculation is performed as shown in Expression (2). At this time, since the multiplication process is performed four times, the effect of low consumption cannot be expected. However, considering the usage time of the water discharger, there is a time zone during which the water discharger is not used (the object 8 exists). Time period) is dominant, even if the digital filter processing is performed as usual during the object detection, it can be said that the ratio is very small in terms of the overall consumption.

  The determination of the output value of the standing wave detecting means 22 may be made based on whether the magnitude is to be distinguished and whether the threshold value is larger or smaller. In the present embodiment, a threshold value for determining whether the output value of the standing wave detecting means 22 is small or slightly large and a threshold value for determining slightly large or large may be provided.

  The flow of changing the above calculation method is summarized as shown in the flowchart of FIG. First, the output value of the standing wave detection means is acquired (S000). Subsequently, the output value of the standing wave detecting means is determined. If the value is small (small in S001), it is approximated as X (0) = X (1) = X (2) = X (3). A necessary frequency component can be obtained by calculating (S002) and (2) as (2) ′ (S003).

  If the output value of the standing wave detecting means is slightly large (slightly large in S001), the data of equation (2) is approximated as X (0) = X (1), X (2) = X (3). A necessary frequency component can be obtained by calculating (S004) and (2) as (2) ′ ′ (S005).

  If the output value of the standing wave detecting means is large (large in S001), a necessary frequency component can be obtained by calculating the data of equation (2) as it is (S006). In other words, the calculation processing load of the equation (2) changes according to the approximate expression, and the consumption of the water discharge device 1 is reduced by reducing the calculation processing load in the time zone when the water discharge device that can be said to be dominant in the day is not used. Electric power can be reduced.

(Second embodiment)
FIG. 8 shows a detailed configuration diagram of the microwave Doppler sensor and the control unit of the second embodiment. Compared with the configuration of the first embodiment, the configuration of the micro Doppler sensor 7 is the same, but the configuration of the control unit 9 is different.

  In the first embodiment, the presence or absence of the object 8 is determined based on the output of the frequency component detection means 23. If the frequency component detecting means 23 is used, only necessary frequency components are extracted, so that the noise resistance is improved. However, since the delay element 31 is used in the configuration of the FIR filter, the presence / absence of the object 8 is determined. Therefore, there is a delay until the effective frequency component is output. In the second embodiment, the configuration is made in consideration of this problem.

  In the second embodiment, an amplifier 41 is provided to produce a signal Sig5 as a first signal obtained by amplifying the signal of Sig4, and a signal Sig4 as a second signal amplified by a gain smaller than that of the amplifier 41 or not amplified. In the present embodiment, an example in which amplification is not performed will be described. That is, a signal far from the microwave Doppler sensor and a nearby signal are used as input signals. The flow until detection will be described with reference to the flowchart of FIG.

  Sig 5 is input to the standing wave detection means 22 and the frequency component detection means 23. The processing of the input signal and the operations of the object detection determination means 24 and the calculation method variable means 25 are the same as those in the first embodiment. (S100)

  If the determination result of the object detection determination means 24 at this time is that there is no object (no object in S101), the object is detected again. If the determination result of the object detection determining means 24 is that there is an object (the object is present in S101), it is determined that the object exists far away, and there is a possibility that the object will come closer and use the water discharge device. The second standing wave detecting means 42 is operated (S102). The reason why the nearby detector is detected by the standing wave is that the standing wave detecting means has a lighter processing load than the frequency component detecting means, so that the result can be derived at high speed. Moreover, although there is a concern about erroneous detection due to noise in the case of detection using a standing wave, since the detection of a distant object has already been confirmed by the frequency component detection means 23, the risk of erroneous detection due to noise can be reduced. Furthermore, in order to set a time limit for detecting the object by Sig4, the timer 43 starts time counting (S103).

  The elapse of the time limit by the timer 43 is confirmed. If the time limit has not elapsed (No in S104), the object detection by Sig4 is performed (S105). If the time limit has elapsed (Yes in S104), the process proceeds to S108. An object is detected by Sig4 (S105). This is determined by the object detection determining means 24 based on whether the output value of the second standing wave detecting means 42 is larger or smaller than the threshold value as in the first embodiment. When the output value of the second standing wave detection means 42 is larger than the threshold value, it is determined that there is an object, and when it is smaller, it is determined that there is no object. Subsequently, if the result of the object detection determination unit 24 is that there is no object (no object in S106), the process returns to S104 to loop the process. If the result is that there is an object (the object is present in S106), the process proceeds to S107, and the detection of the object is confirmed. Subsequently, the time counting by the timer 43 is stopped in S108, and the second standing wave detecting means 42 is stopped in S109. This is to stop unnecessary functions and reduce consumption.

  By performing such a process, it is possible to prevent erroneous detection of noise, and to detect a detection object without causing a delay of the FIR filter while reducing consumption.

DESCRIPTION OF SYMBOLS 1 ... Water discharging apparatus 2 ... Basin 3 ... Water discharging part 4 ... Water supply path 5 ... Water supply valve 6 ... Drainage path 7 ... Microwave Doppler sensor 8 ... Object 9 ... Control part 10 ... Oscillation circuit 11 ... Transmission means water discharging part 12 ... Reception means 13 ... mixing means 21 ... low-pass filter 22 ... standing wave detection means 23 ... frequency component detection means (FIR filter)
24 ... Object detection determination means 25 ... Calculation method variable means 31 ... Delay element 32 ... Filter coefficient 41 ... Amplifier 42 ... Second standing wave detection means 43 ... Timer

Claims (2)

  A water discharge unit, a sensor unit that acquires information on the movement of the detected object by the reflected wave of the radiated radio wave, and a control unit that controls water discharge from the water discharge unit based on a detection signal from the sensor unit, The control unit performs standing wave detection means for detecting a standing wave included in the detection signal from the sensor unit, and digital filter processing for detecting a frequency component included in the detection signal from the sensor unit. Frequency component detection means, wherein the control unit varies the calculation method of the digital filter processing according to the output value of the standing wave detection means, and the frequency component detection means uses the variable calculation method A water discharger characterized by detecting a frequency component contained in an output of a sensor unit.   The water discharge apparatus according to claim 1, wherein the control unit includes a first signal amplified by an amplifier to detect a user's approach and an amplifier used by the first signal to detect the presence of the user. A second signal amplified by a smaller gain or not amplified at all is input, and the control unit includes a standing wave detecting means for detecting a standing wave included in the first signal, and included in the first signal. Frequency component detection means for performing digital filter processing for detecting a frequency component to be detected, and second standing wave detection means for detecting a standing wave included in the second signal, and the control unit The water discharger characterized by operating said 2nd standing wave detection means according to the output result of a standing wave detection means and said frequency component detection means.