JP2011102783A - Human body detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exactly obtain the action state of a person with a small amount of operation, in a human body detector using a Doppler signal. <P>SOLUTION: This human body detector using the Doppler signal of a propagation wave reflected by a human body includes a propagation wave transmitting section for radiating a propagation wave toward the human body, a propagation wave receiving section for receiving the propagation wave reflected by the human body, a Doppler signal generating section for generating the Doppler signal based on the propagation wave radiated by the propagation wave transmitting section and the propagation wave received by the propagation wave receiving section, a Doppler signal analysis section for analyzing the Doppler signal generated by the Doppler signal generating section and calculating the amplitude of the Doppler signal, and an action state determining section that, when the amplitude of the Doppler signal exceeds a first amplitude threshold and then becomes lower than the first amplitude threshold, estimates the distance to the human body based on the amplitude of the Doppler signal at a predetermined time before that point of time and determines the action state of the human body based on the estimation result. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a human body detection device, and more particularly, to a human body detection device using a Doppler signal of a propagation wave reflected by a human body that is a detection target.

  In Japanese Laid-Open Patent Publication No. Sho 62-132484 (Patent Document 1), a microwave is emitted to a front area of a urinal, and a microwave Doppler frequency signal reflected from an object to be detected is transmitted to a plurality of different frequency bands. Detection is performed separately, and human behavior is determined using the fact that detection signals in the plurality of Doppler frequency bands are generated in a certain order.

  Japanese Patent Laid-Open No. 9-80150 (Patent Document 2) describes a human body detection device. In this human body detection device, a microwave is emitted to the front of the toilet, the microwave reflected by the object is received, the power spectrum of the Doppler frequency signal is obtained, and the human action is based on the peak value of the power spectrum. The state is being judged.

  Furthermore, in the urinal washing apparatus described in Japanese Patent Laid-Open No. 2006-214156 (Patent Document 3), a plurality of frequency filters that allow only a specific frequency band signal to pass through are used as the output signal of the microwave Doppler sensor. The action state of the person is determined based on the output signals that have passed through the plurality of frequency filters.

  These human body detection devices using microwaves described in Patent Literature 1 to Patent Literature 3 are different from human body detection devices using infrared rays that are currently widely used, and when applied to a urinal or the like, Since it is not necessary to provide a window for transmitting infrared rays in the main body or the like, there are few restrictions on the conditions for installing the apparatus, and a urinal with a clean design can be realized.

JP 62-132484 A Japanese Patent Laid-Open No. 9-80150 JP 2006-214156 A

  However, in the human body detection device described in Patent Document 1, the speed and direction of movement when a person uses a urinal or a urinal varies depending on the time. For this reason, it is impossible to reliably determine a person's action only by whether signals in a plurality of frequency bands appear in a certain order. For example, the same Doppler frequency pattern is not clearly obtained when the urinal is approached slowly at first, then stops halfway, and further approaches the urinal with a quick start, and when approaching while gradually slowing down at the beginning. Thus, there is a problem that it is difficult to create a database of all patterns in which various people move. In addition, since the action is determined based only on the frequency information, a moving body that is not a detection target, for example, movement of another person or water flow may be erroneously detected as a movement of the detection target.

  Further, in the human body detection device described in Patent Document 2, since the power spectrum is obtained by performing Fourier transform on the detected Doppler signal, there is a problem that it is not possible to grasp the human action state in time series. is there. That is, in the human body detection apparatus described in Japanese Patent Application Laid-Open No. 9-80150, the power spectrum is obtained by performing fast Fourier transform on 128 pieces of data obtained by sampling the Doppler signal over 0.64 sec at 5 msec intervals. ing. The peak frequency and amplitude information obtained from the power spectrum obtained in this way represents the average value over 0.64 seconds of sampled data, and immediately detects changes in human behavior to be detected. There is a problem that you can not.

  In addition, in the method of obtaining the power spectrum by fast Fourier transform, there is a problem that if the number of data to be sampled is reduced, the resolution of the obtained peak frequency is lowered. In addition, if the sampling interval is shortened and a large amount of data is acquired in a short time and fast Fourier transform is performed, the amount of calculation increases, and the power consumed by the human body detection device increases due to a large amount of calculations. is there.

  On the other hand, the frequency filter used in the apparatus described in Patent Document 3 can be realized by applying a digital filter to the detected Doppler signal. I need it. Further, since only a single data in the frequency domain is obtained using a single digital filter, it is not possible to sufficiently grasp the behavior of a person to be detected, and therefore, described in JP-A-2006-214156. This apparatus uses three types of filters. If the number of filters is increased in this way, the amount of calculation increases and it is necessary to use a high-performance microcomputer, and there is a problem that a human body detection device cannot be realized at low cost.

  Accordingly, an object of the present invention is to provide a human body detection device that can accurately grasp a human behavior state with a small amount of computation in a human body detection device using a Doppler signal of a propagation wave reflected by a human body. It is said.

In order to solve the above-described problem, the present invention is a human body detection device using a Doppler signal of a propagation wave reflected by a human body, and a propagation wave transmitting unit that radiates a propagation wave toward the human body, and a human body A propagation wave receiver for receiving the reflected propagation wave;
A Doppler signal generation unit that generates a Doppler signal based on a propagation wave radiated by the propagation wave transmission unit and a propagation wave received by the propagation wave reception unit, and an analysis of the Doppler signal generated by the Doppler signal generation unit A Doppler signal analyzer that calculates the amplitude of the Doppler signal, and when the Doppler signal amplitude exceeds a predetermined first amplitude threshold value and then falls below the first amplitude threshold value, An action state determination unit that estimates the distance to the human body based on the amplitude of the signal and determines the action state of the human body based on the estimation result;
It is characterized by having.

  In the present invention configured as described above, since the Doppler signal analysis unit only has to calculate the amplitude from the Doppler signal, for example, the Doppler signal can be analyzed by a particle filter using an autoregressive model. And, when the amplitude of the Doppler signal exceeds the first amplitude threshold value and falls below the first amplitude threshold value, the distance to the human body can be easily obtained by using the amplitude of the Doppler signal before a predetermined period from that time point. And the action state of the human body can be accurately determined based on the distance. Therefore, Fourier transformation and digital filter calculation are not required to determine the action state of the human body, and the amount of calculation required for the Doppler signal analysis unit can be reduced.

  Further, in the present invention described in claim 2, when the behavior state determination unit is less than the first amplitude threshold value after the Doppler signal amplitude exceeds the first amplitude threshold value, the behavior state determination unit is a predetermined time before that point. When the amplitude of the Doppler signal exceeds a second amplitude threshold value that is larger than the first amplitude threshold value, it is determined that the human body is approaching and stationary and an approach stop detection signal is output.

  In the present invention configured as described above, when the amplitude of the Doppler signal exceeds the first amplitude threshold value and falls below the first amplitude threshold value, the Doppler signal is within a range of a predetermined time before that point. If the amplitude of the signal exceeds a second amplitude threshold value that is greater than the first amplitude threshold value, it is determined that the human body is approaching and stationary. This is the principle feature of the sensor. It uses the fact that the amplitude of the Doppler signal increases when the person approaches the sensor, and decreases when the person moves away from the sensor. If it is determined whether there is a large Doppler signal amplitude in the vicinity of the position at that time, it can be determined that the person is near the sensor, and if not, it can be determined that the person is away from the sensor. Note that the reason why the amplitude is observed for a predetermined time before the time when it falls below the first amplitude threshold is to remove the influence of the standing wave, which is another feature of the Doppler signal. As described above, when the Doppler signal falls below the first amplitude threshold, it is possible to easily grasp whether the person is far away or because the person is still nearby.

  According to the third aspect of the present invention, after the behavior state determination unit outputs the approach stop signal, the amplitude of the Doppler signal is larger than the first amplitude threshold and smaller than the second amplitude threshold. When the third amplitude threshold value is exceeded, the duration is counted, and when the measured time exceeds a predetermined time threshold value, it is determined that the human body is separated, and the output of the approach stop detection signal is stopped.

  According to the present invention configured as described above, since the amplitude of the Doppler signal exceeds the third amplitude threshold larger than the first amplitude threshold, it is detected whether the human body has started moving after the approach stop determination. The movement to the extent that it shakes can be canceled. And if the duration after starting movement exceeds a predetermined time threshold value, it can be determined that the approach stop state is lost, and the output of the approach stop detection signal can be stopped at an appropriate timing.

  According to a fourth aspect of the present invention, the Doppler signal analysis unit analyzes the Doppler signal generated by the Doppler signal generation unit to calculate the amplitude and frequency of the Doppler signal, and the amplitude is a predetermined first value. When the amplitude threshold is exceeded, the moving speed of the human body is calculated based on the frequency of the Doppler signal at that time, and the accumulated human body is calculated based on the calculated moving speed and the time after exceeding the first amplitude threshold. The cumulative movement distance for calculating the movement distance is calculated, and when the amplitude of the Doppler signal exceeds the first amplitude threshold and then falls below the first amplitude threshold, the cumulative movement at that time is calculated. If the amplitude of the Doppler signal exceeds a second amplitude threshold value that is larger than the first amplitude threshold value within a range that is a predetermined distance threshold value before the distance, it is determined that the human body is approaching and stationary. And outputs a proximity stop detection signal.

  In the present invention configured as described above, when the amplitude of the Doppler signal exceeds the first amplitude threshold value and then falls below the first amplitude threshold value, a range that is a predetermined distance threshold value before the cumulative moving distance at that time The distance to the human body is estimated based on the amplitude of the Doppler signal, and the action state of the human body is determined based on the estimation result. This is the principle feature of the sensor. It uses the fact that the amplitude of the Doppler signal increases when the person approaches the sensor, and decreases when the person moves away from the sensor. It can be determined that the person is near the sensor by judging whether there is a large Doppler signal amplitude that exceeds the second amplitude threshold value near the position at the time, and otherwise it can be judged that the person is away from the sensor. . Note that looking at the amplitude within a range that is a predetermined distance threshold before the cumulative travel distance when it falls below the first amplitude threshold removes the influence of the standing wave, which is another feature of the Doppler signal. Because. As described above, when the Doppler signal falls below the first amplitude threshold, it is possible to accurately grasp whether a person is far away or whether the person is stationary within a distance within a desired distance from the sensor.

  Further, in the present invention according to claim 5, after the behavior state determination unit outputs the approach stop signal, an amplitude of the Doppler signal is larger than the first amplitude threshold and smaller than the second amplitude threshold. When the three amplitude threshold value is exceeded, calculation of the cumulative movement distance of the human body is started, and when the cumulative movement distance exceeds a predetermined distance threshold value, it is determined that the human body is separated and the output of the approach stop detection signal is stopped. It is a feature.

  According to the present invention configured as described above, since the amplitude of the Doppler signal exceeds the third amplitude threshold larger than the first amplitude threshold, it is detected whether the human body has started moving after the approach stop determination. The movement to the extent that it shakes can be canceled. When the accumulated movement distance after the start of movement exceeds a predetermined distance threshold value, it can be determined that the approach stop state is lost, and the output of the approach stop detection signal can be stopped at an accurate timing.

  Further, in the present invention according to claim 6, when the behavior state determination unit outputs the approach stop signal and the amplitude of the Doppler signal exceeds the first amplitude threshold, the behavioral state determination unit calculates the cumulative movement distance of the human body. When the frequency drops below the first amplitude threshold, the fourth Doppler signal amplitude is larger than the second amplitude threshold within a range that is a predetermined distance threshold before the cumulative moving distance at that time. If it exceeds the amplitude threshold, it is judged that the human body is approaching and stationary, and a second approach stop detection signal is output.

  In the present invention configured as described above, after determining the approach stop, a fourth amplitude threshold value larger than the first amplitude threshold value used for the determination is used to detect that the approach stop is further approached. Since the second approach / stop detection signal is output, the approach / stop state of the human body can be accurately determined.

  Further, in the seventh aspect of the present invention, after the behavior state determination unit outputs the second approach stop signal, the amplitude of the Doppler signal is larger than the first amplitude threshold and larger than the fourth amplitude threshold. When the small fifth amplitude threshold value is exceeded, calculation of the cumulative movement distance of the human body is started, and when the cumulative movement distance exceeds a predetermined distance threshold value, it is determined that the human body is separated and the output of the second approach stop detection signal is output. While stopping, the approach stop detection signal is output, and thereafter, the output of the approach stop signal is stopped when the cumulative movement distance exceeds a second distance threshold value greater than the distance threshold value.

  According to the present invention configured as described above, after the second approach stop is detected, there is no further movement approaching the sensor, so that the next time the human body moves is away from the sensor, the Doppler signal If the amplitude value exceeds the fifth amplitude threshold, the output of the second approach stop detection is stopped (released) based on the accumulated movement distance, and if the human body is moving continuously, the output of the approach stop detection Since it stops, it is possible to accurately detect the separation of the human body.

  According to the human body detection device of the present invention, it is possible to accurately grasp the human behavior state with a small amount of calculation. In addition, not only the frequency of the Doppler signal proportional to the movement of the person but also the amplitude intensity of the Doppler signal that depends on the distance between the sensor and the person is used to determine the behavior of the person, It is possible to judge human behavior accurately without being confused by the flow of water.

It is a block diagram which shows the whole structure of the urinal by embodiment of this invention. It is a graph which shows an example of the Doppler signal produced | generated by the Doppler signal production | generation part by the example of a urinal. It is a graph showing an example of the moving speed calculated using the particle filter based on the Doppler signal at the time of use of the urinal shown in FIG. 2, a signal amplitude, and a cumulative moving distance. An example of the graph which shows the value of the Doppler signal at the time of use of the urinal shown in FIG. 2, a moving speed, a signal amplitude, a cumulative moving distance, and the action of the determined person is shown. It is a flowchart which shows the process in the urinal of embodiment of this invention. It is a block diagram which shows the whole structure of the toilet bowl by embodiment of this invention. It is a graph which shows an example of the Doppler signal produced | generated by the Doppler signal production | generation part by the case of the toilet bowl by embodiment of this invention. It is a graph showing an example of the moving speed calculated using the particle filter based on the Doppler signal at the time of using the toilet shown in FIG. 7, the signal amplitude, and the accumulated moving distance. An example of the graph which shows the value of the Doppler signal at the time of use of the toilet shown in FIG. 7, a moving speed, a signal amplitude, a cumulative moving distance, and the action of the determined person is shown. It is a flowchart (the first half) which shows the process in the toilet bowl of embodiment of this invention. It is a flowchart (latter half) which shows the process in the toilet bowl of embodiment of this invention. It is a flowchart which shows the process in the urinal (2nd embodiment) of this invention. An example of the graph which shows the value of the Doppler signal at the time of using the urinal shown in FIG. 12, a moving speed, a signal amplitude, a cumulative moving distance, and the action of the determined person is shown.

A preferred first embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing the overall configuration of a urinal according to an embodiment of the present invention.

  As shown in FIG. 1, a urinal 1 according to an embodiment of the present invention discharges a urinal body 2, a human body detection device 4 built in the urinal body 2, and washing water for washing the urinal body 2. And an electromagnetic valve 6 to be stopped, and an electromagnetic valve control unit 8 for controlling the electromagnetic valve 6.

  In the urinal 1 of the present embodiment, when the human body detecting device 4 detects that a person has stopped approaching the urinal body 2 with the addition of urine, the electromagnetic valve control unit 8 sends a signal to the electromagnetic valve 6, The urinal body 2 is pre-cleaned by opening it for a predetermined time. Further, in the urinal 1, when the human body detecting device 4 detects that the person who has added the urinal has left the urinal body 2, the electromagnetic valve control unit 8 sends a signal to the electromagnetic valve 6, which is opened for a predetermined time. The urinal body 2 is then washed afterwards.

The urinal body 2 includes a bowl portion 2a for receiving urine, a spout 2b provided at the upper portion of the bowl portion for discharging the washing water for washing the bowl portion 2a, and for discharging urine and washing water. And a drain port 2c.
The electromagnetic valve 6 is provided in a water supply pipe connected to the water discharge port 2b, and is configured to be opened and closed by a signal sent from the electromagnetic valve control unit 8.

  When the human body detecting device 4 detects "approach of the human body" indicating that the human body has approached the urinal body 2 with a small amount of use and stopped, the electromagnetic valve control unit 8 receives this detection signal for a predetermined time. The electromagnetic valve 6 is opened and pre-cleaning is performed. Further, when the human body detecting device 4 detects that the human body detecting device 4 has moved away from the urinal body 2 by the human body detecting device 4, the electromagnetic valve 6 receives the detection signal for a predetermined time. Is opened and post-cleaning is performed. Specifically, the electromagnetic valve control unit 8 can be configured by a microprocessor, a memory (not shown), and the like.

  The human body detection device 4 is built in the urinal body 2, and is a microwave transmission unit 10 that is a propagation wave transmission unit that radiates a microwave that is a propagation wave toward a human body that is a detection target, and the microwave transmission unit. The microwave receiving unit 12 which is a propagation wave receiving unit that receives the microwaves radiated from 10 and reflected by the human body, the microwaves radiated by the microwave transmitting unit 10 and the microwaves received by the microwave receiving unit 12 And a Doppler signal generation unit 14 for generating a Doppler signal based on the above.

  Further, the human body detection device 4 analyzes the Doppler signal generated by the Doppler signal generation unit 14 and calculates the frequency of the Doppler signal, the moving speed of the detection target object, and the accumulated movement distance from the start of detecting the detection target object. Doppler signal analysis unit 16 that calculates the amplitude of the signal, and an action state determination unit that determines an action state of a person based on an output from the Doppler signal analysis unit 16 and an action state determination result one period before the sampling cycle 18 and. In the present embodiment, the human body detection device 4 is built in the urinal body 2, but the human body detection device 4 may be disposed outside the urinal body 2.

  The microwave transmission unit 10 is configured to radiate microwaves from the back side of the urinal body 2 toward the human body approaching the urinal 1. Specifically, the microwave transmission part 10 can be comprised by the microwave oscillator which transmits the microwave of a predetermined frequency at a predetermined time interval. The microwaves radiated from the microwave transmission unit 10 pass through the ceramic urinal body 2 and are radiated toward the front of the urinal body 2.

  The microwave receiving unit 12 is configured to receive the microwave radiated from the microwave transmitting unit 10 and reflected by the human body to be detected. The microwave reflected by the human body passes through the urinal body 2 again and is received by the microwave receiving unit 12 disposed on the back side of the urinal body 2. Specifically, the microwave receiving unit 12 can be configured by a microwave receiver.

  The Doppler signal generation unit 14 is configured to generate a Doppler signal by mixing a part of the microwave radiated from the microwave transmission unit 10 and the microwave received by the microwave reception unit 12 with a mixer. ing. The generated Doppler signal is a signal that contains a lot of frequency components according to the moving speed of the human body reflecting the microwave. The frequency is high when the moving speed is high, and the frequency is low when the moving speed is low. Become.

  The Doppler signal analysis unit 16 analyzes the Doppler signal generated by the Doppler signal generation unit 14 using, for example, an autoregressive model, calculates the frequency of the Doppler signal and the amplitude of the Doppler signal, and calculates the calculated frequency. The moving speed of the detection target is calculated based on the above, the moving distance of unit time is calculated by the product of the moving speed and the sampling time, and the accumulated moving distance is calculated by integrating the moving distance.

  The behavior state determination unit 18 determines whether the human body is approaching or the human body is based on the cumulative travel distance calculated by the Doppler signal analysis unit 16, the amplitude of the Doppler signal, and the behavior determination result one period before the sampling period. It is configured to determine a person's behavioral state such as “withdrawal”. Details of the calculation processing in the behavior state determination unit 18 will be described later. Specifically, the Doppler signal generation unit 14, the Doppler signal analysis unit 16, and the behavior state determination unit 18 may be configured by an A / D converter, a memory, a microprocessor, a program for operating the A / D converter, and the like. it can.

Next, processing executed by the Doppler signal analysis unit 16 and the behavior state determination unit 18 according to the embodiment of the present invention will be described with reference to FIGS.
FIG. 2 is a graph showing an example of a Doppler signal generated by a Doppler signal generation unit in a urinal according to the present invention. FIG. 3 is a graph showing an example of the movement speed of a person, the amplitude of the Doppler signal, and the total movement distance calculated using the particle filter and the autoregressive model based on the Doppler signal shown in FIG. FIG. 4 is a graph showing an example of the value of the sampled Doppler signal, the movement speed of the person calculated based on the value, the amplitude of the Doppler signal, the total movement distance, and the action of the person determined by the action state determination unit. It is.

  First, when a person approaches the urinal 1 from a distance, stops for a while in the vicinity of the urinal 1, and then makes a half turn and moves away from the urinal 1, the Doppler signal generation unit 14 A Doppler signal as shown in FIG. 2 is output. Note that the horizontal axis in FIG. 2 represents time series, the numerical value on the horizontal axis represents the number of steps for sampling data, and the vertical axis represents the amplitude of the Doppler signal. In FIG. 2, the Doppler signal is sampled at intervals of 4/1024 sec. Although FIG. 2 shows data sampled at intervals of 4/1024 sec, the present invention can be applied even if Doppler signals are sampled at coarser intervals than in FIG.

The Doppler signal analysis unit 16 calculates the frequency of the Doppler signal and the amplitude of the Doppler signal by using, for example, a particle filter technique using an autoregressive model for the Doppler signal shown in FIG. The movement speed v of the person and the Doppler frequency fd have the following relationship, and can be calculated by obtaining the Doppler frequency.
fd = 2fs · v / c (Formula 1)
Where fd: Doppler frequency fs: microwave sensor transmission frequency (10.525 GHz in this example)
vt: human moving speed at time t c: speed of light (3 × 10 ⁸ m / sec)
It is. If the movement speed of the person at time t is obtained, the cumulative movement distance L can be calculated by the following equation.
L = Σ (vt · Δt) (Formula 2)
Where Δt: interval for calculating the movement speed of a person (sampling period)
It is.

  The Doppler signal analysis unit 16 starts calculating the movement speed of the person, the amplitude of the Doppler signal, and the cumulative movement distance L using the formulas 1 and 2 as the first amplitude threshold that the amplitude of the Doppler signal is set in advance. This is when the threshold value B is exceeded. The threshold value B is set to a value larger than the fluctuation (dark noise) of the sensor signal in a state where no person is present in front of the sensor, and is set as a value that is considered that the sensor has detected a reflected wave from some object.

  Furthermore, in the present embodiment, the Doppler signal analysis unit 16 can calculate the movement speed of the person, the amplitude of the Doppler signal, and the cumulative movement distance L, and obtain a result as shown in FIG.

  Using the movement speed of the person, the amplitude of the Doppler signal, and the cumulative movement distance L calculated by the Doppler signal analysis unit 16, the action state determination unit 18 determines the action of the person. The index indicating the human behavior state is set to a value “4” in the initial state, which indicates that the person is not in front of the sensor. When a person approaches the sensor in this state, when the amplitude of the Doppler signal becomes larger than the threshold value B, the Doppler signal analysis unit 16 calculates the movement speed and the accumulated movement distance L of the person. The behavior state determination unit changes the estimated indicator of the behavior state of the person from “4” to “0” when the behavior state of the person one period ago is “4” and the cumulative movement distance is greater than zero. It has become. Here, the estimated index “0” of the human behavior state indicates that the sensor has detected the person, but still indicates a state where the distance to the sensor is farther than the preset (a + e). This is defined as approach 1.

On the other hand, as a feature of the operation of a person using a urinal, it was found that there is a state that can be regarded as stationary for a short time of several hundred msec before performing a specific operation such as before use. Moreover, when a person uses a urinal, it is necessary to approach the urinal to some extent. When using a urinal, the distance between a person and the urinal is set to 30 cm at the maximum, the signal amplitude intensity when a small child stands in front of the sensor and moves the body as a threshold A as a second amplitude threshold, Once there is a signal exceeding the signal amplitude threshold A within 15 cm from the position where the person is stationary, it is determined that the person is within 45 cm from the sensor and is stationary, and within 15 cm as the distance threshold from the current position When the signal amplitude intensity is smaller than the signal amplitude A, it is determined that the person is not within 45 cm from the sensor. In FIG. 4, a person's stillness is detected after 2 seconds, and a signal exceeding the threshold A exists up to a distance of 15 cm before that, so that the person exists within a distance of 45 cm from the sensor. That is, the estimated indicator of the human behavior state is changed from the previous determination “0” to “1”. This state is defined as approach 2.
The reason why it is determined whether or not the signal is larger than the signal amplitude threshold A within a distance threshold (for example, 15 cm) from the position where the person is stationary is for the purpose of removing the influence of the standing wave often generated in the Doppler signal. A standing wave is generated from the overlap of multiple reflected radio waves, and the location of the standing wave depends on the radio wave transmission distance and depends on the wavelength of the radio wave. Since the wavelength of the microwave is several centimeters, if a section sufficiently longer than the wavelength is monitored as a distance threshold, a region that is not affected by the standing wave always appears.

  In addition, the signal amplitude threshold A is about 80% after it is determined that the person's behavioral state estimation index of the previous period is “1” and the person is stationary within a distance of 45 cm from the sensor. A threshold D as a third amplitude threshold of the amplitude of the Doppler signal is set in advance, and when the amplitude intensity of the Doppler signal is smaller than the threshold D, the movement distance is set to 0 and the threshold D is exceeded. The travel distance and the cumulative travel distance are calculated. By doing this, it is possible to eliminate the effects of hand movement and slight body movement that a person moves for small use, and to calculate the movement distance after the person really starts to move. In this way, when the estimated indicator of the behavioral state of the person in the previous period is “1” and the cumulative movement distance of the person is further 10 cm or more, the behavioral state determination unit 18 makes the determination “1” in the previous period. To "0".

  In addition, when the estimated index of the behavioral state of the person in the previous period is “0”, the amplitude intensity of the sensor is small and it is determined that the sensor is stationary, the amplitude intensity threshold A or more is within 25 cm from the current position. If there is no signal of size, it is assumed that the person is 55 cm or more away from the sensor, and the behavioral state determination unit 18 is changed from the previous determination “0” to “4”. If there is a signal with an amplitude intensity A or more within a distance of 25 cm from that point in time, the human activity state estimation index is “0”, assuming that the person is still at a distance of 55 cm from the sensor. Keep it.

    Next, the operation of the urinal 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flowchart showing processing by the human body detection device 4 in the urinal of the present embodiment.

  First, in step S1 of FIG. 5, when the human body detection device 4 is powered on, the process proceeds to step S2 and enters a standby mode. In this standby mode, the microwave transmission unit 10 radiates microwaves in front of the urinal 1, and the microwave reception unit 12 receives microwaves. The Doppler signal generation unit 14 generates a Doppler signal based on the radiated microwave and the received microwave. Further, the Doppler signal analysis unit 16 is generated and sampled when the amplitude intensity of the microwave is larger than a threshold B (first amplitude threshold) having a level equivalent to the dark noise appearing in the Doppler signal when no human body is present. The Doppler signal is analyzed, and the moving speed of the person, the amplitude of the Doppler signal, and the total moving distance are sequentially calculated.

  Next, in step S3, it is determined whether or not a person has approached the vicinity of the urinal 1. That is, the behavior state determination unit 18 determines whether or not a person has approached based on the calculated movement speed of the person, the amplitude of the Doppler signal, the total movement distance, and the action state determination result of the previous period. The behavior state determination unit 18 regards a person as “approaching” if the following two conditions (a) and (b) are satisfied. (a) The action state determination one period ago is “no person”. (b) The cumulative travel distance is greater than zero.

  When these two conditions (a) and (b) are satisfied, the behavior state determination unit 18 determines that the person's behavior state is “approach” to the vicinity of the urinal, and the processing is step S4. Proceed to If the three conditions are not satisfied, the process returns to step S2 and the standby state is maintained.

  In step S4, it is recognized that the action state of the person is “approaching”. Further, in step S5, it is determined whether or not the person approaching the urinal 1 is stationary and starts to use. That is, the behavior state determination unit 18 determines whether or not the following three conditions (c) to (e) are satisfied. (C) The action state determination of the previous period is “approach”. (D) The signal amplitude is smaller than the threshold B. (e) There is a signal larger than the signal amplitude intensity threshold A (second amplitude threshold) at a distance within 15 cm from the current position.

  When these three conditions (c) to (e) are satisfied, the behavior state determination unit 18 determines that a person approaching the urinal has started to use (determines that the approach is stationary) The approach stop signal is output), and the process proceeds to step S6. On the other hand, if it is not determined that the person has started to use even after a predetermined time has elapsed after the approach state is recognized in step S3, the process proceeds to step S7 to determine whether the person has left.

  In step S6, the human body detection device 4 becomes “determination 1” which is an approach stop detection signal, and based on this, the electromagnetic valve control unit 8 sends a control signal to the electromagnetic valve 6 to open the electromagnetic valve 6 for a predetermined time. Thereby, washing water is discharged from the water outlet 2b of the urinal body 2, and the bowl part 2a is pre-washed.

  Next, in step S <b> 7, it is determined whether or not the person has left the vicinity of the urinal 1. That is, when a signal exceeding the threshold value D is obtained, the behavior state determination unit 18 determines whether the following two conditions (f) and (g) are satisfied. (F) The state behavior determination of the person before one period is “starting the small use”. (G) From the time when it was determined that the small use was started, the cumulative moving distance moved by 10 cm or more.

  When these two conditions (f) and (g) are satisfied, the behavior state determination unit 18 determines that the person who started the small use has left, and the process proceeds to step S8. On the other hand, if the two conditions are not satisfied, the determination in step S7 is repeated.

  In step S8, the determination is “0”. (The output of the stationary detection signal “1” is stopped.)

  In step S9, it is called from the memory where the presence / absence data for small use in step 5 is stored in the state where it is determined to be “removed” in step 8, and if small use is determined, the process proceeds to step 10. If small usage is not determined, the process returns to step S2.

  In step S10, the solenoid valve control unit 8 sends a control signal to the solenoid valve 6 to open the solenoid valve 6 for a predetermined time. Thereby, the wash water is discharged from the water outlet 2b of the urinal body 2, and the bowl portion 2a is post-washed.

  Next, an embodiment of the toilet of the present invention will be described. FIG. 6 shows an embodiment of the toilet of the present invention. The toilet shown in FIG. 6 includes a toilet 110, a cleaning tank 112 that supplies cleaning water to the toilet 110, and a warm water cleaning toilet seat 115 that has a human body local cleaning mechanism installed in the toilet 110. . In addition, the toilet 110 includes a human body detection device 200 using a microwave sensor for detecting approach and seating of a person.

  The toilet 110 of the present embodiment is a motor that opens and closes the toilet lid 121 by a control unit (not shown) in the warm water flush toilet seat 115 when the human body detection device 200 detects that a person has approached the toilet body 110. A signal is sent to the stool to open the stool lid so that a person can sit on the toilet 110. Further, when the human body detection device 200 of the toilet 110 detects that a person is seated on the seat surface 120, the person operates the operation unit of the remote controller 51, and receives a signal from the infrared transmission unit 52 by the warm water washing toilet seat unit. In response to a signal received through a window (not shown), a control unit inside the warm water washing toilet seat 115 realizes an operation according to the signal. Specifically, for example, functions such as local cleaning and drying. When the human body detection device 200 detects that the person has left the toilet body 110, the person operates the operation unit of the remote controller 51, and the signal from the infrared transmitter 52 is received by a reception window (not shown) of the hot water washing toilet seat. The control unit in the warm water washing toilet seat is configured not to function even when receiving the signal received in (1). Further, when the human body detection device 200 detects that the person is seated and then moves away from the toilet 110, the control unit in the warm water washing toilet seat 115 controls the electromagnetic valve of the washing tank 112 and causes the washing tank 112 to flow. The toilet 110 is washed. After the electromagnetic valve is opened for a predetermined time, the electromagnetic valve is closed by the control unit, and water is again stored in the washing tank 112. Next, when a person moves further away from the toilet bowl or the human body detection device completely stops detecting a person, the control unit in the warm water washing toilet seat 115 sends a signal to the motor that opens and closes the toilet lid 121, It is configured to close.

  FIG. 7 shows an example of the sensing result of the microwave sensor when a person approaches the toilet having the microwave sensor shown in FIG. 6 and sits and leaves after use and leaves the toilet. FIG. 7 shows how a person is operating together with sensor output data. First of all, no people are detected when sensing is started. At about 6 seconds, the Doppler signal amplitude intensity corresponding to the start of human detection can be observed, and then a Doppler signal corresponding to the human motion can be obtained. After that, since the person is stationary at about 13 seconds, the amplitude intensity of the Doppler signal becomes almost zero. Here, the toilet is used, and at about 25 seconds after use, a person stands up, performs a reversal operation, and is separated from the toilet.

    Next, processing executed by the Doppler signal analysis unit and the behavior state determination unit in the embodiment applied to the toilet of the present invention will be described with reference to FIGS. FIG. 8 is a graph showing an example of the moving speed of a person, the amplitude of the Doppler signal, and the cumulative moving distance calculated using the particle filter and the autoregressive model based on the Doppler signal shown in FIG. FIG. 9 is a graph showing an example of the value of the sampled Doppler signal, the movement speed of the person calculated based on the value, the amplitude of the Doppler signal, the accumulated movement distance, and the action of the person determined by the action state determination unit. It is.

  First, a person approaches the toilet 110 from a distance, temporarily stops in the vicinity of the toilet 110, and then performs a seating operation by half-turning the body. During sitting, the Doppler signal has a small amplitude intensity, and most people It becomes the same signal as the absence. Further, when the use of the toilet is finished, the user sits away from the toilet 110, stands up, leaves the toilet 110 and leaves the toilet booth, a Doppler signal as shown in FIG. 7 is output. Note that the horizontal axis of FIG. 7 represents time, and the vertical axis represents the amplitude of the Doppler signal.

  The Doppler signal analysis unit (not shown in FIG. 6) that has received the Doppler signal as shown in FIG. 7 uses the Doppler signal shown in FIG. Using the relationship, the moving speed of the person, the amplitude of the Doppler signal, and the cumulative moving distance L are calculated.

  It is the first amplitude threshold that the Doppler signal amplitude is set in advance that the Doppler signal analysis unit starts calculating the movement speed of the person, the amplitude of the Doppler signal, and the cumulative movement distance L using Equations 1 and 2. This is when the threshold value B is reached. The threshold value B is set to a value larger than the fluctuation (dark noise) of the sensor signal in a state where no person is present in front of the sensor, and is set as a value that is considered that the sensor has detected a reflected wave from some object. In the second embodiment, the threshold value B is 2500.

  Furthermore, in the present embodiment, the Doppler signal analysis unit can calculate the moving speed of the person, the amplitude of the Doppler signal, and the cumulative moving distance L, and obtain a result as shown in FIG.

  Using the movement speed of the person, the amplitude of the Doppler signal, and the cumulative movement distance L calculated by the Doppler signal analysis unit, the action state determination unit (not shown in FIG. 6) determines the person's action as follows. A determination result of 9 is obtained. The determination indicating the behavior state of the person indicates that the person is not in front of the sensor by a numerical value “4”. When a person approaches the sensor in this state, when the amplitude of the Doppler signal becomes larger than the threshold value B, the Doppler signal analysis unit calculates the movement speed of the person, the amplitude of the Doppler signal, and the cumulative movement distance L. . The action state determination unit changes the determination result of the person's action state from “4” to “0” when the action state of the person one period before is “4” and the cumulative movement distance is greater than zero. It has become. Here, the determination result “0” of the person's action state indicates that the sensor has detected the person, but still indicates a state where the distance to the sensor is longer than the preset (a + e). In this embodiment, the distance a is 30 cm and the distance e is 15 cm.

  Furthermore, as a feature of the operation of a person using a toilet, it has been found that there is a state that can be regarded as stationary for a short time of several hundred msec before performing a certain operation such as before using the toilet. Here, being able to be regarded as stationary is defined as a state in which the amplitude intensity of the Doppler signal of the human body detection device is equivalent to the amplitude intensity level when the person is not in front of the sensor. Moreover, in order for a person to use a toilet bowl, it is necessary to approach the toilet bowl to some extent. When the toilet is used, the distance at which it stops once in front of the toilet is set to a maximum of 30 cm, and the signal amplitude intensity when a small child stands in front of the sensor and moves the body at this distance is set to A2 (second amplitude threshold value). ), When there is a signal exceeding the signal amplitude threshold A2 within 15 cm from the position where the person is stationary, it is determined that the person is present within 45 cm from the sensor and is stationary and within 15 cm from the current position. When the signal amplitude intensity is smaller than the signal amplitude A2, it is determined that the person is not within 45 cm from the sensor. In FIG. 9, a person's stillness is detected a little before 10 seconds, and a signal exceeding the threshold value A2 exists up to a distance of 15 cm before that, so that the person exists within a distance of 45 cm from the sensor. Therefore, the determination of the human behavior state is changed from the previous determination “0” to “1”. Judgment “1” indicates that there is a person within 45 cm from the toilet. In this embodiment, 10000 is adopted as the signal amplitude threshold A2.

In addition, after determining that the person's behavior state one period before is “1” and that the person is stationary within a distance of 45 cm from the sensor, the Doppler is about 80% of the signal amplitude threshold A2. A threshold value D2 (third amplitude threshold value) of the signal amplitude is set in advance, and when the amplitude intensity of the Doppler signal is less than or equal to this threshold value D2, the movement distance is set to 0, and after exceeding the threshold value D2, The travel distance and the cumulative travel distance are calculated. In this way, it is possible to eliminate the effects of hand movements and slight body movements that a person moves for stool, and to calculate the movement distance after the person really starts moving. In addition, as the fourth amplitude threshold value that occurs when the person's behavioral state of the previous period is “1”, the cumulative movement distance of the person is further 5 cm or more, and the Doppler signal amplitude is within 15 cm from the sensor. When Doppler signal amplitude intensity A3 is set, A3> A2 is established, and it is detected whether a person is further approaching the sensor based on whether the Doppler signal amplitude value is A3 or more within 5 cm from the current position. The state determination unit is changed from the previous determination “1” to “3”.
Judgment “3” means that a person is moving within 15 cm from the sensor. In this embodiment, 8000 is used as the threshold D2, and 15000 is used as A3.

  Next, when the determination of the behavior state of the person in the previous period is “3”, the amplitude intensity of the sensor is small and it is determined that the sensor is stationary, the amplitude intensity threshold A3 or more within a distance of 15 cm from the current position. If there is a signal of magnitude, it is assumed that the person is seated, and the behavioral state determination unit is changed from the previous determination “3” to “5”. The judgment “5” indicates a state where a person is seated on the seat 120. If there is no signal greater than the amplitude intensity A3 within a distance of 15 cm from that point, the human activity state estimation index is “1”, assuming that the person is still at a distance of 45 cm from the sensor. Keep it.

  Next, in the state where the determination of the behavior state of the person in the previous period is “5”, the sensor detects the movement of the person as an amplitude D3 (for example, the amplitude D3 is an 80% signal of the amplitude A3). ) Detecting whether there is the above Doppler signal, and when the cumulative movement distance increases by 10 cm or more from the position of the action determination “5”, the action state determination unit is changed from the previous determination “5” to “6” . The judgment “6” indicates that the person has left the seat 120.

  Further, when the estimated index of the behavioral state of the person in the previous period is “6”, the amplitude intensity of the sensor is small, and it is determined that the sensor is stationary, the amplitude amplitude greater than or equal to the signal amplitude intensity A2 within 25 cm from the current position. If there is, the action state determination unit is changed from the previous determination “6” to “1”.

  Furthermore, when the estimated index of the behavioral state of the person one period before is “1”, it moves 5 cm or more from the time when it becomes “1”, and there is no signal exceeding the signal amplitude A2 within 15 cm from the position at that time. At this time, the behavior state determination unit is changed from the previous determination “1” to “0”.

  Furthermore, when the estimated index of the action state of the person in the previous period is “0”, the amplitude intensity of the sensor is small and it is determined that the sensor is stationary, a signal exceeding the signal amplitude A2 is within 20 cm from the position at that time. If not, the behavior state determination unit is changed from the previous determination “1” to “4”.

  Next, the operation will be described with reference to flowcharts 10 and 11 when the present invention is applied to a toilet. First, in step S51 of FIG. 10, when the human body detection device 200 is turned on, the process proceeds to step S52 to enter a standby mode. In this standby mode, a microwave transmitter (not shown) radiates microwaves in front of the toilet 110, and a microwave receiver (not shown) receives microwaves. A Doppler signal generation unit (not shown) generates a Doppler signal based on the radiated microwave and the received microwave. When a person approaches the sensor in this state, when the amplitude of the Doppler signal becomes larger than the threshold value B (Taichi amplitude threshold value), the Doppler signal analysis unit (not shown) performs sampling of the Doppler signal. And sequentially calculating the moving speed of the person, the amplitude of the Doppler signal, and the cumulative moving distance.

  Next, in step S53, it is determined whether or not a person has approached within a distance (a + e: 45 cm in this embodiment) from the toilet 110. That is, the behavior state determination unit (not shown) determines whether or not the person has approached based on the calculated movement speed of the person, the amplitude of the Doppler signal, the accumulated movement distance, and the action state determination result of the previous period. judge. If the following two conditions (a) and (b) are satisfied, the behavior state determination unit regards the person as “approach 1”. (a) The action state determination one period ago is “no person”. (b) The cumulative travel distance is greater than zero.

  When these two conditions (a) and (b) are satisfied, the process proceeds to step S54, and the behavior state determination unit determines that the behavior state of the person is within a distance (a + e) from the toilet. At the same time, a motor for opening and closing the toilet lid 121 is driven using the control unit inside the warm water flush toilet seat 115, and the toilet lid 121 is opened. If the three conditions are not satisfied, the process returns to step S52 and the standby state is maintained.

  Further, in step S55, it is determined whether or not the person who has approached 1 of the toilet bowl 110 has further approached the toilet bowl. That is, the behavior state determination unit determines whether the approach / stop operation is performed based on whether or not the following three conditions (c) to (e) are satisfied. (C) The action state determination of the previous period is “approach (“ 0 ”)”. (D) The signal amplitude was small and the signal was determined to be stationary. (E) There is a signal larger than the threshold A2 (second amplitude threshold) of the signal amplitude intensity at a distance within 15 cm from the current position.

  When these three conditions (c) to (e) are satisfied, the behavior state determination unit determines that a person approaching the toilet has approached and stopped within 15 cm from the toilet. As approach 2 ”, the process proceeds to step S56. On the other hand, if it is not determined that the person has approached within 15 cm from the toilet after the approach 1 state is recognized in step S54, the process proceeds to step S55 or step 67.

  In step S56, the action state of the person is recognized as “approach 2”. Furthermore, in step S57, if a person moves in the vicinity of the toilet, the signal becomes larger than the threshold A3 of the Doppler signal amplitude intensity. Using this fact, the behavior state determination unit determines whether the “sitting operation” is performed based on whether the following two conditions (f) and (g) are satisfied. (F) The action state determination of the previous period is “approach 2”. (G) There is a signal larger than the threshold A3 of the signal amplitude intensity at a distance within 15 cm from the current position.

If these two conditions (f) and (g) are satisfied, the behavior state determination unit determines that the person is about to sit on the toilet bowl, and determines that the determination is “sitting operation” in step 58. move on. (F) When (g) is not satisfied, the routine proceeds to step 57 or step 65.

  Next, in step S59, it is determined whether a person has been seated on the toilet. That is, the behavior state determination unit determines whether or not the following three conditions (h) to (j) are satisfied. (H) The state / behavior determination of the person one period before is “sitting operation (“ 3 ”)”. (I) Since the amplitude intensity of the Doppler signal is small, it can be determined that the signal is stationary. (J) There is a signal exceeding the amplitude intensity A3 (fourth amplitude threshold) within 10 cm from the stationary position.

  If these three conditions (h) to (j) are satisfied, the behavior state determination unit determines that the person is “sitting” in step 60, and the process proceeds to step S60. In this step S60, it is determined as sitting ("5": second approach stop detection signal) as a judgment. At the same time, a signal is output from the control unit inside the warm water cleaning toilet seat 115, a motor for driving a local cleaning nozzle (not shown) is operated, the local cleaning nozzle is slightly moved forward from the storage unit, and the cleaning water is supplied to the nozzle. Cleaning is performed for a set time, the cleaning water is stopped, and the cleaning nozzle is stored in the storage unit. Further, when seating is detected, an operation signal receiving unit (not shown) in the local cleaning function unit 115 receives an operation signal of the remote control 51, and the remote control operation signal is received in the hot water washing toilet seat 115 according to the signal. It implements using the microprocessor in a control part so that a control part may function. On the other hand, when the three conditions are not satisfied, the determination in step S58 is repeated, and the operation signal of the remote controller 51 is ignored by the local cleaning function unit 115 and is not functioned or proceeds to step 63.

  In step S61, it is determined whether or not the person has left the toilet. That is, when an amplitude signal exceeding the threshold value D3 is obtained, the behavior state determination unit determines whether the following three conditions (n) to (p) are satisfied. (N) The determination of the state and behavior of a person before one period is “sitting”. (O) Moved 5 cm or more from the stationary state (p) There is no signal exceeding the amplitude intensity A3 within 10 cm from the current position.

  When these three conditions (n) to (p) are satisfied, the behavioral state determination unit determines that the person has left the toilet and then left the toilet slightly. And the process proceeds to step S63. At the same time, even if an operation signal receiving unit (not shown) in the local cleaning function unit 115 receives an operation signal from the remote controller 51, the control unit in the warm water cleaning toilet seat 115 functions according to the signal. It implements using the microcomputer in a control part. On the other hand, when the three conditions are not satisfied, the determination in step S61 is repeated and the operation of the remote controller functions.

  In step S63, it is determined whether or not the person who has left the seat is about to leave the toilet. That is, the behavior state determination unit determines whether or not the following three conditions (q) to (s) are satisfied. (N) The determination of the state and behavior of the person one period before is “seating”. (O) Moved 20 cm or more from the stationary state (p) There is no signal exceeding the amplitude intensity A2 within 10 cm from the current position.

  When these three conditions (q) to (s) are satisfied, the behavior state determination unit determines that the person has left the toilet slightly in step 64 and determines “approach 2”. The process proceeds to step S65. At the same time, a control unit inside the warm water flush toilet seat 115 is used to control an electromagnetic valve (not shown) of the flush water tank 112 so that flush water flows and the toilet 110 is washed. On the other hand, when these three conditions (q) to (s) are not satisfied, step 63 is repeated or the process returns to step 59.

  In step S65, it is determined whether or not a person who has already moved away from the toilet at a distance of about “approach 2” has further moved away from the toilet and has reached the same distance as “approach 1”. That is, the behavior state determination unit determines whether or not the following three conditions (t) to (v) are satisfied. (T) The state / behavior determination of the person one period before is “approach 2)”. (U) Doppler signal amplitude intensity is small and can be determined to be stationary. (V) There is no signal exceeding amplitude intensity A2 within 15 cm from the current position.

  When these three conditions (t) to (v) are satisfied, the behavior state determination unit determines that the person is at the same distance as “approach 1” with respect to the toilet bowl in step 66 “approach 1”. And the process proceeds to step S67. At the same time, the controller that drives the opening / closing of the toilet lid 121 is driven using the control unit inside the warm water flush toilet seat 115 to close the toilet lid 121. On the other hand, when these three conditions (t) to (v) are not satisfied, the process returns to step 63.

  In step S67, it is determined whether or not a person who has already moved away from the toilet bowl at a distance of about “approach 1” has further moved away from the toilet bowl and has entered the “exit” state. That is, the behavior state determination unit determines whether or not the following three conditions (t) to (v) are satisfied. (T) The state action determination of a person before one period is “approach 1”. (U) Doppler signal amplitude intensity is small and can be determined to be stationary. (V) There is no signal exceeding amplitude intensity A2 within 15 cm from the current position.

  When these three conditions (t) to (v) are satisfied, the behavior state determination unit determines that the person has “exited” and determines “exit” in step 68, and the process proceeds to step S68. move on. If it becomes step 68, the flow from step 51 is repeated again. On the other hand, when these three conditions (t) to (v) are not satisfied, the process returns to step 53.

  Next, with reference to FIG. 12 and FIG. 13, the process which the Doppler signal analysis part 16 in the urinal in connection with 2nd embodiment of this invention and the action state determination part 18 perform is demonstrated. In this embodiment, the frequency analysis of the Doppler sensor signal is not performed, and the action determination using the amplitude intensity and time is performed. To perform this, first, detection is started in Step 101, and then the signal amplitude of the sensor is detected in Step 103. It is determined whether or not it is larger than a detection start signal amplitude which is a preset first amplitude threshold value indicating the approach of. If the signal amplitude is smaller than the detection start signal amplitude, the process returns to step 102. If the signal amplitude is larger than the detection start signal amplitude, it is determined that a person has approached, and the process proceeds to step 104.

  In step 104, it is determined that a person is approaching the sensor (toilet bowl), and the determination is changed from “0” to determination “1”. This change in judgment is shown in the example of FIG. If the approach of a person is detected, the process proceeds to step 105.

  In step 105, based on the time when the sensor detects a person, a value having the smallest signal amplitude within a preset amplitude calculation interval (700 msec in the present embodiment) is calculated as a reference signal amplitude. The maximum value of the signal amplitude is calculated as the first amplitude value during the interval until the image becomes stationary, and the signal amplitude of the second magnitude is calculated as the second amplitude value after the first amplitude value before and after the first amplitude value.

  In step 106, it is determined whether the signal amplitude smaller than the detection start signal amplitude continues for a preset threshold time after the signal amplitude becomes larger than the third amplitude value set in advance by means described later, When it continues, it progresses to step 108, and it is judged in step 108 that the person is still in front of the sensor or no longer in front of the sensor. If the duration time is short, the process proceeds to Step 107.

  In step 107, it is determined whether or not the amplitude calculation time has elapsed since the sensor started detection. If the time has not elapsed, it is determined that the sensor has stopped halfway to the sensor, and the process returns to step 105. If the time has elapsed, it is determined that the person is no longer in front of the sensor, and the determination is “0” and the process proceeds to step 115.

  In step 108, the human judgment remains in two ways, but in step 109, using the leaving time set in advance based on the latest time when the signal amplitude value is larger than the fourth signal amplitude (second amplitude threshold value). Then, it is determined whether the time difference of the latest time when the signal amplitude value is larger than the fourth signal amplitude from the time of proceeding to step 108 is longer than or less than the time of leaving. If the time is less than the leaving time, the process proceeds to step 110, and the determination is changed from determination "1" to determination "2" on the assumption that the person is stationary in front of the sensor. If the time goes away and is more than the time, it is determined that the person is no longer in front of the sensor, and the determination is “0”.

  In step 111, if the signal amplitude is equal to or larger than the third amplitude threshold value which is a ratio not exceeding 100% of the fourth amplitude value (80% in this embodiment), it is determined that a large object including the body has moved. Then, the process proceeds to step 112, and the determination is made as a movement determination from determination "2" to determination "1".

  In step 113, if the time that the signal amplitude value is smaller than the detection start signal amplitude continues for a preset threshold time or more, the process proceeds to step 114, and if the continuation is short, the process returns to step 112.

  In step 114, it is determined whether the time of the latest time difference having a signal amplitude value larger than the fourth signal amplitude is equal to or longer than the take-off time. To do. If it is less than the leaving time, the process returns to step 112, and it is determined that the person has stopped a little while moving.

  In step 116, the first amplitude value is compared with the third amplitude value, the smaller one is set as a new third amplitude value, the second amplitude value is compared with the fourth amplitude value, and the smaller one is set as a new fourth amplitude value. . By doing in this way, the threshold value according to the toilet installation environment can be updated.

  Furthermore, in the above-described embodiment, microwaves are used as propagating waves radiated toward the object to be detected. However, electromagnetic waves other than microwaves, laser light, ultrasonic waves, etc. can be measured using the Doppler effect. Any propagating wave can be used.

DESCRIPTION OF SYMBOLS 1 Urinal by embodiment of this invention 2 Urinal body 2a Bowl part 2b Water outlet 2c Drainage port 4 Human body detection apparatus 6 Electromagnetic valve 8 Electromagnetic valve control part 10 Microwave transmission part (propagation wave transmission part)
12 Microwave receiver (propagating wave receiver)
DESCRIPTION OF SYMBOLS 14 Doppler signal generation part 16 Doppler signal analysis part 18 Behavior state determination part 51 Remote control 52 Remote control transmission part 110 Toilet bowl 112 Washing tank 113 Drain lever 114 Hand wash spout 115 Hot water washing toilet seat 120 Toilet lid 200 Human body detection apparatus

Claims (7)

A human body detection device using a Doppler signal of a propagation wave reflected by a human body,
A propagation wave transmitter that emits a propagation wave toward the human body;
A propagation wave receiver for receiving a propagation wave reflected by the human body;
A Doppler signal generation unit that generates a Doppler signal based on the propagation wave radiated by the propagation wave transmission unit and the propagation wave received by the propagation wave reception unit;
A Doppler signal analyzer that analyzes the Doppler signal generated by the Doppler signal generator and calculates the amplitude of the Doppler signal;
When the amplitude of the Doppler signal exceeds the predetermined first amplitude threshold value and then falls below the first amplitude threshold value, the distance to the human body is estimated based on the amplitude of the Doppler signal before a predetermined period from that time point, An action state determination unit for determining the action state of the human body based on the estimation result;
A human body detection device comprising:   If the amplitude of the Doppler signal exceeds the first amplitude threshold and falls below the first amplitude threshold, the behavior state determination unit determines that the amplitude of the Doppler signal is within a predetermined time period before that point. 2. The human body detection device according to claim 1, wherein when the second amplitude threshold value is larger than the first amplitude threshold value, it is determined that the human body is approaching and stationary and an approach stop detection signal is output.   If the amplitude of the Doppler signal exceeds a third amplitude threshold value that is greater than the first amplitude threshold value and smaller than the second amplitude threshold value after outputting the approach stop signal, the behavior state determination unit continues its duration. 3. The human body detection device according to claim 2, wherein when the measured time exceeds a predetermined time threshold, it is determined that the human body is separated and the output of the approach stop detection signal is stopped. The Doppler signal analysis unit analyzes the Doppler signal generated by the Doppler signal generation unit to calculate the amplitude and frequency of the Doppler signal, and when the amplitude exceeds a predetermined first amplitude threshold, the Doppler signal at that time The moving speed of the human body is calculated based on the frequency of the human body, and the cumulative moving distance is calculated based on the calculated moving speed and the time after the first amplitude threshold is exceeded. And
The behavior state determination unit, when the amplitude of the Doppler signal exceeds the first amplitude threshold and then falls below the first amplitude threshold, within a range that is a predetermined distance threshold before the cumulative movement distance at that time 2. The approach stop detection signal is output when it is determined that the human body is approaching and stationary when the amplitude of the Doppler signal exceeds a second amplitude threshold value greater than the first amplitude threshold value. Human body detection device.   When the behavior state determination unit outputs the approach stop signal and the amplitude of the Doppler signal exceeds a third amplitude threshold value that is greater than the first amplitude threshold value and smaller than the second amplitude threshold value, 5. The human body detection according to claim 4, wherein calculation of the cumulative movement distance is started, and when the cumulative movement distance exceeds a predetermined distance threshold, it is determined that the human body is separated and output of the approach stop detection signal is stopped. apparatus.   The behavior state determination unit starts calculating the cumulative movement distance of the human body when the amplitude of the Doppler signal exceeds the first amplitude threshold after outputting the approach stop signal, and then the first amplitude threshold If the amplitude of the Doppler signal exceeds the fourth amplitude threshold value that is greater than the second amplitude threshold value within a range that is a predetermined distance threshold value before the cumulative moving distance at that time, The human body detection device according to claim 4, wherein the human body detection device outputs a second approach stop detection signal based on the determination that the approach is stationary.   When the behavior state determination unit outputs the second approach stop signal and the amplitude of the Doppler signal exceeds a fifth amplitude threshold value that is larger than the first amplitude threshold value and smaller than the fourth amplitude threshold value, Calculation of the cumulative movement distance of the human body is started, and when the cumulative movement distance exceeds a predetermined distance threshold, it is determined that the human body is separated and the output of the second approach stop detection signal is stopped and the approach stop detection signal is output. 7. The human body detection device according to claim 6, wherein when the cumulative moving distance thereafter exceeds a second distance threshold value that is larger than the distance threshold value, the output of the approach stop signal is stopped.