Motion detection system, wiring device, load system, motion detection method, and program

Abstract

To suppress false positives. [Solution] The motion detection system 1 comprises a radio wave sensor 10, a detection unit 22, and a sensitivity setting unit 24. The radio wave sensor 10 transmits a frequency-modulated radio wave, which is a transmission wave, to the detection target space SP1 during each of a plurality of detection periods. When the radio wave sensor 10 receives a reflected wave, which is the reflection of the transmission wave at the reflection point of an object present in the detection target space SP1, it outputs an output signal based on the transmission wave and the reflected wave. The detection unit 22 calculates the time difference, which is the difference in the output signal intensity of two output signals output by the radio wave sensor 10 during two different detection periods, and detects the presence or absence of a moving object based on the comparison result obtained by comparing the time difference with a threshold. When the switching condition based on the time difference is met, the sensitivity setting unit 24 switches the object detection sensitivity of the detection unit 22 from the first sensitivity to a second sensitivity which is more sensitive than the first sensitivity.

Description

Technical Field

[0001] The present disclosure relates to a moving body detection system, wiring equipment, a load system, a moving body detection method, and a program. More specifically, the present disclosure relates to a moving body detection system, wiring equipment, a load system, a moving body detection method, and a program that detect an object in motion using a radio wave sensor.

Background Art

[0002] Patent Document 1 discloses an intrusion detection device including a transmission unit, a reception unit, a received wave intensity measurement unit, and a human body determination unit. The transmission unit transmits radio waves into a detection area. The reception unit receives the reflected wave of the transmitted radio waves. The received wave intensity measurement unit measures the received wave intensity of the reflected wave received by the reception unit. The human body determination unit determines whether a human body has intruded into the detection area based on the measured received wave intensity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to detect minute movements of the human body associated with breathing, when the detection sensitivity of the human body by the human body determination unit is set to high sensitivity, there is a possibility of erroneously detecting the movement of an object other than the human body (for example, the movement of a foliage plant or a curtain swaying in the wind).

[0005] An object of the present disclosure is to provide a moving body detection system, wiring equipment, a load system, a moving body detection method, and a program capable of suppressing false detection.

Means for Solving the Problems

[0006] A motion detection system according to one aspect of the present disclosure comprises a radio wave sensor, a detection unit, and a sensitivity setting unit. The radio wave sensor transmits a frequency-modulated radio wave, which is a transmission wave, to the detection target space during each of a plurality of detection periods. When the radio wave sensor receives a reflected wave, which is the transmission wave reflected at the reflection point of an object present in the detection target space, it outputs an output signal based on the transmission wave and the reflected wave. The detection unit calculates a time difference, which is the difference in the output signal intensity of two output signals output by the radio wave sensor during two different detection periods, and detects the presence or absence of a moving object based on the comparison result obtained by comparing the time difference with a threshold. When a switching condition based on the time difference is met, the sensitivity setting unit switches the object detection sensitivity of the detection unit from a first sensitivity to a second sensitivity that is more sensitive than the first sensitivity.

[0007] A wiring device according to one aspect of the present disclosure comprises a motion detection system, a load connection section, and a load control section. A load is connected to the load connection section. The load control section controls the operating state of the load connected to the load connection section based on the object detection result by the motion detection system.

[0008] A load system according to one aspect of the present disclosure comprises the motion detection system, a load, and a load control unit. The load control unit controls the operating state of the load based on the object detection result by the motion detection system.

[0009] A motion detection method according to one aspect of the present disclosure includes an acquisition process, a detection process, and a sensitivity setting process. In the acquisition process, the output signal output from a radio wave sensor for each detection period is acquired. In each of the plurality of detection periods, the radio wave sensor transmits a frequency-modulated radio wave, which is a transmission wave, to the detection target space. When the radio wave sensor receives a reflected wave, which is the reflection of the transmission wave at the reflection point of an object present in the detection target space, it outputs an output signal based on the transmission wave and the reflected wave. In the detection process, a time difference is calculated, which is the difference in the output signal intensity of two output signals output by the radio wave sensor during two different detection periods, and the presence or absence of a moving object is detected based on the comparison result obtained by comparing the time difference with a threshold. In the sensitivity setting process, when a switching condition based on the time difference is met, the detection sensitivity of the object in the detection process is switched from a first sensitivity to a second sensitivity that is more sensitive than the first sensitivity.

[0010] A program according to one aspect of this disclosure is a program for causing one or more processors to execute the motion detection method. [Effects of the Invention]

[0011] According to this disclosure, false positives can be suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic block diagram of a wiring device and load system equipped with a motion detection system according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a conceptual diagram of a room to which the wiring device equipped with the motion detection system described above is applied. [Figure 3] Figure 3 is a graph showing the changes in the frequencies of the transmitted and received waves transmitted by the radio wave sensor in the motion detection system described above. [Figure 4] Figure 4 is a diagram that conceptually explains the inter-frame difference performed by the motion detection system described above. [Figure 5]Figure 5 is a frequency spectrum diagram showing an example of the FFT result obtained by the motion detection system described above in frame Fr0. [Figure 6] Figure 6 is a frequency spectrum diagram showing an example of the FFT results obtained by the motion detection system described above in frame Fr1. [Figure 7] Figure 7 is a frequency spectrum diagram showing an example of the time difference obtained by the motion detection system described above from the FFT results of frame Fr0 and frame Fr1. [Figure 8] Figure 8 is a distribution map showing the distribution of points representing moving objects detected by the motion detection system described above. [Figure 9] Figure 9 is a schematic diagram illustrating the movement of a person passing through the detection area of ​​the motion detection system described above. [Figure 10] Figure 10 is a graph showing the time change of the integrated time difference calculated by the detection unit of the motion detection system described above. [Figure 11] Figure 11 is a schematic diagram illustrating the movement of a person moving within the detection area of ​​the motion detection system described above, when they stop midway and then start moving again. [Figure 12] Figure 12 is a graph showing the time change of the integrated time difference calculated by the detection unit of the motion detection system described above. [Figure 13] Figure 13 is a flowchart illustrating the operation of the wiring device mentioned above. [Modes for carrying out the invention]

[0013] Hereinafter, the motion detection system, wiring device, load system, and motion detection method according to the embodiments will be described in detail with reference to the drawings. However, the figures described in the following embodiments are schematic diagrams, and the dimensional ratios of the size of each component do not necessarily reflect the actual dimensional ratios. Furthermore, the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0014] (Embodiment) (1) Overview As shown in FIG. 1, the moving object detection system 1 according to the present embodiment includes a radio wave sensor 10, a detection unit 22, and a sensitivity setting unit 24.

[0015] In each of a plurality of detection periods, the radio wave sensor 10 transmits a transmission wave, which is a frequency-modulated radio wave, to a detection target space SP1 (see FIG. 2). When the radio wave sensor 10 receives a reflected wave obtained by reflecting the transmission wave at a reflection point of an object existing in the detection target space SP1, the radio wave sensor 10 outputs an output signal based on the transmission wave and the reflected wave.

[0016] The detection unit 22 calculates a time difference, which is a difference in output signal intensities of two output signals respectively output by the radio wave sensor 10 in two different detection periods, and detects the presence or absence of a moving object based on a comparison result of comparing the time difference with a threshold value.

[0017] When a switching condition based on the time difference is satisfied, the sensitivity setting unit 24 switches the detection sensitivity of the object in the detection unit 22 from the first sensitivity to the second sensitivity, which is higher than the first sensitivity.

[0018] Note that the “time difference, which is a difference in output signal intensities of two output signals” as referred to in the present disclosure includes not only the “time difference value of the output signal intensities” but also the “time difference value corresponding to the time difference value of the output signal intensities”. Therefore, the “time difference, which is a difference in output signal intensities” may include, for example, a time difference value proportional to the time difference value of the output signal intensities.

[0019] The motion detection system 1 of this embodiment detects moving objects (hereinafter sometimes referred to as "motions"), and in this embodiment, the object to be detected by the motion detection system 1 is, for example, a person. The detection target space SP1 in which the motion detection system 1 detects the presence or absence of an object is a space in which a person may be present, for example, the interior space of a residential or non-residential building used by a person. When the motion detection system 1 detects an object moving in the detection target space SP1, it determines that this object is a person. The motion detection system 1 may also determine that an object present in the detection target space SP1 is a person based on the size or height (height) of the object detected in the detection target space SP1.

[0020] In this case, if a person, which is an object in the detection target space SP1, is standing still or sitting in a chair, the movement of the person in the detection target space SP1 will be minute movements that occur when breathing or shifting. If the detection sensitivity of the detection unit 22 is set to high sensitivity (second sensitivity) so that such minute movements can be detected, the detection unit 22 may falsely detect slight movements of objects other than people (for example, houseplants or curtains, etc.) that are blown by the wind. On the other hand, if the detection sensitivity of the detection unit 22 is set to low sensitivity (first sensitivity) to suppress false detections, it may not be able to detect minute movements of objects, and detection failures may occur.

[0021] In the motion detection system 1 of this embodiment, the time difference in the output signal intensity of the two output signals output by the radio wave sensor 10 during the two detection periods is proportional to the amount of movement of the object during the two detection periods. When the switching condition based on the time difference is met, the sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the first sensitivity to the second sensitivity, which is more sensitive than the first sensitivity. Therefore, when the sensitivity setting unit 24 is set to the second sensitivity, even minute movements of the object to be detected can be detected. Also, when the sensitivity setting unit 24 is set to the first sensitivity, the possibility of false detection of objects other than the object to be detected can be reduced, thus suppressing false detections.

[0022] (2) Details The motion detection system 1 of this embodiment is used to detect moving objects using a radio wave sensor 10.

[0023] The motion detection system 1 is provided in a wiring device 100 installed on the ceiling 401 of a room 400 in which a person 300 may be present (see Figure 2). In other words, in this embodiment, the interior space of the room 400 becomes the detection target space SP1 in which the motion detection system 1 detects the presence or absence of a person. The motion detection system 1 includes a housing 2 that houses a radio wave sensor 10, and the housing 2 is placed on a wall 402 next to the detection target space SP1, or on the ceiling 401 above the detection target space SP1. In the following embodiment, the case in which the housing 2 is placed on the ceiling 401 above the detection target space SP1 will be described as an example. In this case, the radio wave sensor 10 is placed on the lower surface of the housing 2 in a state in which it can transmit radio waves to a detection area A1 set in the detection target space SP1 below the ceiling 401.

[0024] Furthermore, in this embodiment, since the motion detection system 1 is provided in the wiring device 100, the housing of the wiring device 100 becomes the housing 2 of the motion detection system 1. The housing 2 of the motion detection system 1 further houses the detection unit 22. If the radio wave sensor 10 and the detection unit 22 were housed in separate housings, the installation work for the radio wave sensor 10 and the detection unit 22 would need to be performed separately. In this embodiment, since the radio wave sensor 10 and the detection unit 22 are housed in a single housing 2, the installation work for the radio wave sensor 10 and the detection unit 22 can be performed at once, simplifying the installation process.

[0025] Furthermore, the wiring device 100 of this embodiment includes a motion detection system 1, a load connection section 50, and a load control unit 23. A load 3 is connected to the load connection section 50. The load control unit 23 controls the operating state of the load 3 connected to the load connection section 50 based on the object detection result by the motion detection system 1. The load 3 whose power operating state is controlled by the load control unit 23 is, for example, a lighting load, but it may also be an air conditioning load such as a ventilation fan, or a load other than a lighting load or air conditioning load.

[0026] (2.1) Configuration The configurations of the motion detection system 1 and the wiring device 100 will be described in more detail below with reference to Figures 1 to 12.

[0027] (2.1.1) Motion detection system The motion detection system 1 includes the radio wave sensor 10 described above. The motion detection system 1 also further includes a processing unit 20 and a storage unit 30.

[0028] The radio wave sensor 10 transmits a frequency-modulated radio wave Tr (see Figure 3) from the transmitting antenna, receives a received wave (reflected wave) Re (see Figure 3) which is the transmitted wave Tr reflected by an object, with the receiving antenna, and outputs an intermediate frequency signal (IF signal) obtained by mixing the transmitted wave Tr and the received wave Re.

[0029] The radio wave sensor 10 comprises an oscillator 11, a transmitter 12, a receiver 13, and a mixer 14.

[0030] The oscillator 11 periodically generates a transmission signal modulated using, for example, a frequency-modulated continuous wave (FMCW) method. Specifically, the oscillator 11 periodically generates a transmission signal that is frequency-modulated such that the frequency continuously increases from f0 to f1 over a predetermined chirp time Tc.

[0031] The transmitting unit 12 outputs the transmission signal generated by the oscillator 11 to the transmitting antenna, causing the transmitting antenna to transmit a transmission wave Tr (see Figure 3). The frequency of the transmission wave Tr increases continuously from f0 to f1 over a predetermined chirp time Tc.

[0032] The receiving unit 13 receives the received wave Re (see Figure 3) reflected by an object (more specifically, the reflection point on the surface of the object) with a receiving antenna, converts the received wave Re into an electrical signal, and outputs the resulting received signal to the mixer 14. The receiving unit 13 also has a function to measure the signal strength of the received wave Re received by the receiving antenna. The radio wave sensor 10 outputs the measurement result of the signal strength of the received wave Re measured by the receiving unit 13 to the processing unit 20.

[0033] Mixer 14 generates an intermediate frequency signal (IF signal) by mixing the transmission signal generated by oscillator 11 and the reception signal output by receiver 13. The IF signal is generated during the period when the transmission wave Tr is being transmitted and the reception wave Re is being received (i.e., from the start of reception of reception wave Re to the end of transmission of transmission wave Tr). The IF signal is a signal that indicates the frequency difference Δf (see Figure 3) between the transmission wave Tr and the reception wave Re. The IF signal is a signal that indicates the difference between the frequency of the transmission wave Tr and the frequency of the reception wave Re at time t, but if the object reflecting the transmission wave Tr is stationary, the IF signal will be a constant value.

[0034] Generally, to determine the three-dimensional position of an object (moving object) to be detected, the radio wave sensor 10 needs to have, for example, one transmitting antenna and three or more receiving antennas. In this embodiment, the radio wave sensor 10 has one transmitting antenna and three receiving antennas. When the radio wave sensor 10 has three receiving antennas, an IF signal is generated by mixing the received signal received by each of the three receiving antennas with the transmitted signal generated by the oscillator 11. Therefore, each time the radio wave sensor 10 performs a transmit / receive operation during each of the multiple detection periods, it outputs three IF signals corresponding to the three receiving antennas. The positions of the one transmitting antenna and the three receiving antennas of the radio wave sensor 10 are known, and the position information of the one transmitting antenna and the three receiving antennas is stored in advance in the storage unit 30. When the radio wave sensor 10 has multiple antennas (including transmitting and receiving antennas), the multiple antennas may be housed in one housing 2 or arranged in multiple locations.

[0035] The processing unit 20 primarily consists of a computer system having one or more processors and memory. The functions of the processing unit 20 are realized when the processor of the computer system executes a program stored in the memory of the computer system. The program may be stored in memory, provided via a telecommunication line such as the Internet, or provided on a non-temporary recording medium such as a memory card.

[0036] The processing unit 20 has the functions of the detection unit 22 and the sensitivity setting unit 24 described above. In this embodiment, the processing unit 20 also has the functions of an acquisition unit 21 and a load control unit 23. Note that the acquisition unit 21, detection unit 22, load control unit 23, and sensitivity setting unit 24 merely represent functions realized by the processing unit 20 and do not necessarily represent an actual physical configuration.

[0037] The storage unit 30 includes, for example, memory such as RAM (Random Access Memory), ROM (Read-Only Memory), and EEPROM (Electrically Erasable Programmable Read-Only Memory). The storage unit 30 stores, for example, the program executed by the processing unit 20. The storage unit 30 also stores the calculation results of the processing unit 20 (for example, the time difference obtained by the detection unit 22, and the integrated value of the time difference), a threshold value to be compared with the time difference, and a switching judgment value to be compared with the integrated value of the time difference.

[0038] The acquisition unit 21 acquires an output signal from the radio wave sensor 10. In this embodiment, the acquisition unit 21 acquires an IF signal as an output signal from the radio wave sensor 10. For example, if the radio wave sensor 10 has three receiving antennas, the acquisition unit 21 acquires three IF signals from the radio wave sensor 10, corresponding to each of the three receiving antennas, for each of the multiple detection periods. The acquisition unit 21 also acquires the measurement results of the signal strength of the received wave Re received by each of the three receiving antennas from the radio wave sensor 10 for each of the multiple detection periods.

[0039] The detection unit 22 applies an FFT (Fast Fourier Transform) to the IF signal acquired by the acquisition unit 21 from the radio wave sensor 10 to obtain the frequency spectrum, and acquires the frequency spectrum as an FFT result. In this embodiment, since the radio wave sensor 10 is equipped with three receiving antennas, the mixer 14 outputs three IF signals between the transmitting wave Tr and the three receiving waves Re received by the three receiving antennas, respectively. Therefore, each time the radio wave sensor 10 performs a transmit / receive operation, the detection unit 22 calculates a group of FFT results including three FFT results (frequency spectra) obtained by applying an FFT to each of the three IF signals, and stores the calculated group of FFT results in the storage unit 30. Here, the group of FFT results obtained in one transmit / receive operation of the transmitting wave Tr and the receiving wave Re includes three FFT results (frequency spectra) obtained by applying an FFT to each of the three IF signals corresponding to the three receiving antennas.

[0040] The radio wave sensor 10 repeats transmission and reception operations at a predetermined period T1. The predetermined period T1 is, for example, 200 mS. The radio wave sensor 10 performs transmission and reception operations at a frequency of once per frame Fr, for example, with one frame Fr being 200 mS (see Figure 4). Here, one frame Fr is the detection period during which the radio wave sensor 10 performs one transmission and reception operation, and the radio wave sensor 10 performs transmission and reception operations in each of multiple detection periods (frames Fr). Note that the duration of one frame Fr is not limited to 200 mS and can be changed as appropriate.

[0041] The process by which the detection unit 22 detects the presence or absence of an object based on two output signals output from the radio wave sensor 10 in two frames FrA and FrB (in other words, two detection periods) will be explained with reference to Figures 4 to 8.

[0042] Figure 4 shows the transmitted wave Tr transmitted by the transmitter 12 in frames FrA and FrB. Figures 5 and 6 show the FFT results (relationship between frequency f and signal strength amp of the received wave Re) obtained by FFT processing the IF signal generated by mixing the transmitted signal and the received signal received by one of the three receiving antennas. Figure 5 shows the FFT result for frame FrA, and Figure 6 shows the FFT result for frame FrB. Here, the multiple peaks appearing in the FFT result (frequency spectrum) correspond to the reflection points of objects that reflected the transmitted wave Tr. The detection unit 22 then calculates the time difference, which is the difference between the frequency spectrum in frame FrA and the frequency spectrum in frame FrB, and thereby obtains the time difference, which is the difference in the output signal strength of the output signal. By calculating the time difference between the frequency spectrum in frame FrA and the frequency spectrum in frame FrB, the detection unit 22 can remove the frequency components corresponding to stationary objects and obtain only the frequency components corresponding to moving objects. Figure 7 shows the time difference between the frequency spectrum at frame FrA and the frequency spectrum at frame FrB. The peaks in the frequency spectrum shown in Figure 7 correspond to moving objects.

[0043] Here, the detection unit 22 compares the time difference obtained as described above with a predetermined threshold L1, and detects the presence or absence of an object based on the comparison result between the time difference and the threshold L1. Specifically, if the time difference of the output signal is greater than or equal to the threshold L1, the detection unit 22 outputs a detection result to the load control unit 23 indicating that a person is present in the detection target space SP1. On the other hand, if the time difference of the output signal is less than the threshold L1, the detection unit 22 outputs a detection result to the load control unit 23 indicating that a person is not present in the detection target space SP1. The detection unit 22 stores the calculation results of the time difference calculated for each of the multiple detection periods in the storage unit 30.

[0044] If the detection unit 22 detects the presence of a moving object (person) in the detection target space SP1, it may further detect the three-dimensional position of the moving object. Each time the radio wave sensor 10 performs a transmit / receive operation, it outputs three IF signals between the transmitted wave Tr and the three received waves Re received by the three receiving antennas. The detection unit 22 can obtain three frequency spectra by performing FFT processing on each of the three IF signals. The detection unit 22 can then determine the distance from each of the three receiving antennas to the moving object by calculating the time difference of the three frequency spectra between two different frames, thereby determining the three-dimensional position of the moving object using three-point positioning.

[0045] If a person is present in the detection target space SP1, the transmitted wave Tr from the transmitter 12 will be reflected by multiple parts (reflection points) of the person's body. The multiple reflected waves reflected by the multiple reflection points are received by the receiver 13, and the mixer 14 outputs an output signal (IF signal) which is a mixture of the multiple reflected waves received by the receiver 13 and the transmitted wave. In other words, the radio wave sensor 10 outputs an output signal based on the reflected waves (received waves Re) reflected by each of the multiple reflection points on the surface of the object and the transmitted wave Tr. When the detection unit 22 applies FFT processing to the output signal from the radio wave sensor 10, multiple peaks corresponding to the multiple reflection points appear in the FFT result (frequency spectrum) of the output signal. The detection unit 22 then calculates the time difference for the multiple peaks corresponding to the multiple reflection points, and acquires one or more reflection points whose time difference is greater than or equal to the threshold L1 as reflection points of a moving object. In other words, the detection unit 22 determines the distribution of one or more reflection points whose time difference is greater than or equal to the threshold L1, and detects the position of a moving object based on this distribution.

[0046] Figure 8 shows a plot of multiple points DT1 on a three-dimensional space 500 representing the room 400, corresponding to multiple reflection points where the time difference of the output signal output from the radio wave sensor 10 is greater than or equal to a threshold L1, when the detection unit 22 detects a person 300 present in the detection target space SP1. When the radio wave sensor 10 is installed on the ceiling 401, the transmitted wave Tr is reflected a lot from the head, shoulders, hands, and feet of the person 300, while reflection of the transmitted wave Tr is less likely to occur from the torso of the person 300. Therefore, multiple points DT1 representing multiple reflection points from the head, shoulders, hands, and feet of the person 300 are plotted on the three-dimensional space 500.

[0047] Here, the detection unit 22 performs clustering on the multiple points DT1 corresponding to each of the multiple reflection points, thereby grouping the multiple points DT1 into one or more clusters. In the example in Figure 8, the multiple points DT1 representing the multiple reflection points are grouped into two clusters: cluster CL1 corresponding to the head, shoulders, hands, etc., of person 300, and cluster CL2 corresponding to the feet of person 300. As shown in Figure 8, when the multiple points DT1 corresponding to person 300 are grouped into two clusters CL1 and CL2, the detection unit 22 can determine the location of person 300 by, for example, determining the centroid position of each of the clusters CL1 and CL2, and then determining the midpoint of the two centroid positions. In other words, the detection unit 22 can determine the location of person 300 based on the distribution of one or more reflection points whose time difference is greater than or equal to the threshold L1.

[0048] In this way, when multiple points DT1 representing person 300 are grouped into multiple clusters, the detection unit 22 determines the centroid position of each cluster and detects the midpoint of the centroid positions of the clusters as the three-dimensional position of the object. The detection unit 22 then determines the distance between the midpoint of the centroid positions of the clusters and the radio wave sensor 10 as the detected distance between the object and the radio wave sensor 10. If multiple points DT1 representing person 300 are detected as a single cluster, the detection unit 22 only needs to detect the centroid position of the cluster as the three-dimensional position of the object and determine the distance between the centroid position of the cluster and the radio wave sensor 10 as the detected distance between the object and the radio wave sensor 10.

[0049] Furthermore, the detection unit 22 determines the distribution of one or more reflection points whose time difference is greater than or equal to the threshold L1, and detects the movement of an object corresponding to the distribution (i.e., one or more reflection points) based on the temporal displacement of this distribution. When an object (e.g., a person) in the detection target space SP1 moves, the distribution of one or more reflection points whose time difference is greater than or equal to the threshold L1 also changes in accordance with the movement of the object. Therefore, the detection unit 22 can detect the movement of an object in the detection target space SP1 by detecting the movement of the distribution of one or more reflection points whose time difference is greater than or equal to the threshold L1.

[0050] Furthermore, in this embodiment, the detection sensitivity of the detection unit 22 is set to either the first sensitivity or the second sensitivity by the sensitivity setting unit 24. More specifically, the sensitivity setting unit 24 sets whether the object detection sensitivity of the detection unit 22 is the first sensitivity or the second sensitivity based on switching conditions based on the time difference.

[0051] Here, the switching condition includes a condition relating to the integrated value obtained by accumulating multiple time differences calculated for each of the multiple detection periods. The detection unit 22 calculates the time difference of the output signal intensity during the difference calculation period between two detection periods by calculating the difference in the output signal intensity of two output signals output by the radio wave sensor 10 for two different detection periods. The sensitivity setting unit 24 obtains an integrated value Sa obtained by accumulating multiple time differences during a predetermined accumulation period up to the current detection period by accumulating the time differences calculated for each of the multiple difference calculation periods. Then, the sensitivity setting unit 24 sets whether the object detection sensitivity of the detection unit 22 is set to the first sensitivity or the second sensitivity based on the switching condition, which is a condition relating to the integrated value Sa.

[0052] Here, the condition regarding the cumulative value Sa of the time difference is, for example, that the cumulative value Sa is equal to or greater than the switching judgment value Th1 (see Figures 10 and 12).

[0053] If the object in the detection target space SP1 is a person sitting in a chair or standing still, the person's movement will be minimal. However, for a person in the detection target space SP1 to reach a stationary state where their movement is minimal, they must transition from an active state, which involves larger movements than the stationary state, to a stationary state, such as sitting down in a chair or walking to a stopping position. In other words, when a person transitions from an active state to a stationary state, the time difference calculated by the detection unit 22 becomes larger in the active state, and the integrated value Sa of the time difference also becomes larger. Therefore, in the motion detection system 1 of this embodiment, the sensitivity setting unit 24 compares the level of the integrated value Sa of the time difference with a predetermined switching judgment value Th1, and when the integrated value Sa of the time difference becomes greater than or equal to the switching judgment value Th1, the detection sensitivity of the detection unit 22 is switched from the first sensitivity to the second sensitivity.

[0054] Thus, when the sensitivity setting unit 24 detects that a person is active in the detection target space SP1, it sets the detection sensitivity of the detection unit 22 to the second sensitivity, thereby ensuring reliable detection of human movement and reducing the possibility of missed detections. However, if there is no person in the detection target space SP1, and only objects other than people that make slight movements (for example, plants or curtains moving in the wind) are present, the cumulative time difference value Sa will not exceed the switching judgment value Th1, so the sensitivity setting unit 24 will not switch the detection sensitivity of the detection unit 22 from the first sensitivity to the second sensitivity. In this case, the detection sensitivity of the detection unit 22 is set to the first sensitivity, which is lower than the second sensitivity, thus reducing the possibility of the detection unit 22 falsely detecting slight movements of objects other than people.

[0055] The sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the second sensitivity to the first sensitivity if, after switching the detection sensitivity of the detection unit 22 to the second sensitivity, the duration T2 of the state in which the time difference is less than the threshold L1 becomes equal to or greater than the recovery time TA1. In other words, the sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the second sensitivity to the first sensitivity if, after switching the detection sensitivity of the detection unit 22 to the second sensitivity, the state in which the detection unit 22 does not detect a moving object continues for a recovery time TA1 or longer. After the sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the first sensitivity to the second sensitivity, if a person who was in the detection target space SP1 leaves the detection target space SP1, the time difference calculated by the detection unit 22 becomes less than the threshold L1. Therefore, if the state in which the time difference calculated by the detection unit 22 remains less than the threshold L1 continues for a recovery time TA1 or longer, the sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the second sensitivity to the first sensitivity. The recovery time TA1 is, for example, 10 seconds, but it can be between 1 second and 10 minutes, and can be changed as appropriate. In this way, when there are no people in the detection target space SP1, the sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the second sensitivity to the first sensitivity, thereby reducing the possibility of false detection of the movement of objects other than people.

[0056] Furthermore, if a person in the detection target space SP1 moves outside of the detection target space SP1, the cumulative value of the time difference Sa will gradually decrease and eventually fall below the switching judgment value Th1. Therefore, the sensitivity setting unit 24 may switch the detection sensitivity of the detection unit 22 from the second sensitivity to the first sensitivity when the cumulative value of the time difference Sa falls below the switching judgment value Th1. In addition, the sensitivity setting unit 24 may switch the detection sensitivity of the detection unit 22 from the second sensitivity to the first sensitivity if the state in which the cumulative value of the time difference Sa is below the switching judgment value Th1 continues for longer than the recovery time, thereby reducing the possibility of the detection sensitivity being changed due to a temporary decrease in the cumulative value Sa.

[0057] The sensitivity setting unit 24 adjusts the detection sensitivity by adjusting the time interval between the two output signals used by the detection unit 22 to calculate the time difference (i.e., the length of the difference calculation period). The sensitivity setting unit 24 lengthens the time interval when the detection sensitivity is set to the second sensitivity compared to the time interval when the detection sensitivity is set to the first sensitivity. The longer the time interval between the two output signals used to calculate the time difference, the greater the amount (distance) that the object is displaced during this time interval. As a result, the detection unit 22 can detect smaller movements of the object, thereby increasing the sensitivity of the detection unit 22. For example, the sensitivity setting unit 24 sets the time interval to 200 milliseconds when the detection sensitivity is set to the first sensitivity and to 700 milliseconds when the detection sensitivity is set to the second sensitivity. Note that the values ​​for the time intervals in the first sensitivity and the second sensitivity are examples and can be changed as appropriate.

[0058] The sensitivity setting unit 24 may also adjust the detection sensitivity by adjusting the value of the threshold L1. For example, the sensitivity setting unit 24 can make the threshold L1 for the second detection sensitivity smaller than the threshold L1 for the first detection sensitivity. By making the value of the threshold L1 smaller, the detection unit 22 can detect the movement of smaller objects, thereby increasing the detection sensitivity of the detection unit 22.

[0059] The sensitivity setting unit 24 may also adjust the detection sensitivity by adjusting both the time interval between the two output signals used by the detection unit 22 to calculate the time difference, and the value of the threshold L1. For example, the sensitivity setting unit 24 may lengthen the time interval when the detection sensitivity is set to the second sensitivity compared to the time interval when the detection sensitivity is set to the first sensitivity, and decrease the threshold L1 when the detection sensitivity is set to the second sensitivity compared to the threshold L1 when the detection sensitivity is set to the first sensitivity. In this way, the sensitivity setting unit 24 can adjust the detection sensitivity of the detection unit 22 by adjusting both the time interval between the two output signals used to calculate the time difference and the threshold L1. The setting information regarding the time interval and threshold L1 for the first and second sensitivities is assumed to be pre-set in the storage unit 30.

[0060] The load control unit 23 executes control processing for load 3 according to the detection result of the detection unit 22. If the detection unit 22 detects that a person is present in the detection target space SP1, the load control unit 23 supplies power to the lighting load, which is load 3, and turns on the lighting load. If the detection unit 22 detects that no person is present in the detection target space SP1, the load control unit 23 cuts off the power supply to the lighting load, which is load 3, and turns off the lighting load. The load control unit 23 will be explained in more detail in "(2.1.2) Wiring Devices".

[0061] (2.1.2) Wiring devices As described above, the wiring device 100 comprises a motion detection system 1 and a load control unit 23. The wiring device 100 further comprises a load connection unit 50, a drive circuit 40, and a switch element 41. In this embodiment, the housing 2 of the motion detection system 1 houses the radio wave sensor 10, the processing unit 20, the storage unit 30, the load connection unit 50, the drive circuit 40, and the switch element 41. In other words, in this embodiment, the functions of the motion detection system 1 and the functions of the wiring device 100 are housed in a single housing 2. Furthermore, the wiring device 100 of this embodiment and the load 3, which is the control target of the load control unit 23, constitute the load system 200.

[0062] The load connection section 50 includes a pair of connection terminals 51 and 52. A series circuit of an AC power supply AC and a load 3 is connected between the pair of connection terminals 51 and 52 via electric wires W1 and W2. The load 3 is, for example, a lighting load. The lighting load 3 has a light source such as an LED (Light Emitting Diode) and a lighting circuit for turning on the light source.

[0063] The switching element 41 is, for example, a semiconductor switching element such as a triac, thyristor, FET (Field effect transistor), or bipolar transistor, or a relay. The switching element 41 is connected between a pair of connection terminals 51 and 52. In other words, a series circuit of the AC power supply AC and the load 3 is connected between both ends of the switching element 41. When the switching element 41 becomes conductive and power is supplied to the load 3, the lighting load 3 lights up. Conversely, when the switching element 41 becomes non-conductive and the power supply to the load 3 is cut off, the lighting load 3 turns off.

[0064] The drive circuit 40 controls the switch element 41 to a conductive or non-conductive state in accordance with the control signal input from the load control unit 23.

[0065] When the detection unit 22 detects the presence of a person, the load control unit 23 outputs a control signal to the drive circuit 40, controlling the switch element 41 to a conductive state, thereby turning on the load 3, which is a lighting load. Conversely, when the detection unit 22 detects the absence of a person, the load control unit 23 outputs a control signal to the drive circuit 40, controlling the switch element 41 to a non-conductive state, thereby turning off the load 3, which is a lighting load.

[0066] Furthermore, if the lighting load, which is load 3, has a dimming function, the load control unit 23 may dim the lighting load, which is load 3, according to the detection result of the detection unit 22. That is, if the detection unit 22 detects the presence of a person, the load control unit 23 may turn on the lighting load, which is load 3, at a first brightness level, and if the detection unit 22 detects the absence of a person, the load control unit 23 may turn on the lighting load, which is load 3, at a second brightness level that is dimmer than the first brightness level. As a result, when there is no person in the detection target space SP1, the brightness of the lighting load, which is load 3, can be controlled to be dimmer than when there is a person, and the power consumption of the lighting load can be reduced.

[0067] For example, the load control unit 23 may output a control signal to the drive circuit 40 for phase control of the switch element 41. The drive circuit 40 controls the switch element 41 to a conductive state for a conduction period corresponding to the control signal during each half-cycle of the AC voltage input from the AC power supply, thereby adjusting the power supplied to the load 3, which is a lighting load, and enabling dimming of the lighting load.

[0068] (2.2) Operation Instructions The operation of the wiring device 100 equipped with the motion detection system 1 of the above embodiment will be explained with reference to Figures 9 to 13. Note that the flowchart shown in Figure 13 is merely one example of the motion detection method according to this embodiment, and the order of processing may be changed as appropriate, or processing may be added or omitted as appropriate.

[0069] The radio wave sensor 10 performs transmission and reception operations in each of the multiple detection periods (frames) and outputs an output signal (IF signal), and the acquisition unit 21 acquires the output signal output from the radio wave sensor 10 in each detection period (S1).

[0070] When the acquisition unit 21 acquires an output signal (IF signal) from the radio wave sensor 10, the detection unit 22 performs FFT processing on the output signal (IF signal) of the radio wave sensor 10 to calculate the FFT result (frequency spectrum) and stores the FFT result in the storage unit 30. Then, the detection unit 22 calculates the time difference, which is the difference between the FFT result calculated in the current frame and the FFT result calculated in the previous frame, and stores the calculated time difference in the storage unit 30 (S2).

[0071] When the detection unit 22 calculates the time difference, the sensitivity setting unit 24 calculates the integrated value Sa of the time differences over multiple difference calculation periods based on the previous integrated value Sb stored in the storage unit 30 and the time difference calculation result calculated by the detection unit 22 in step S2 (S3). The sensitivity setting unit 24 stores the integrated value Sa calculated in step S3 in the storage unit 30.

[0072] Next, the sensitivity setting unit 24 compares the cumulative value Sa obtained in step S3 with the switching judgment value Th1 (S4).

[0073] If the cumulative value Sa in the comparison process in step S4 is equal to or greater than the switching judgment value Th1 (S4: Yes), the sensitivity setting unit 24 determines that there is an active person in the detection target space SP1 and sets the detection sensitivity of the detection unit 22 to the second sensitivity (S6).

[0074] On the other hand, if the cumulative value Sa in the comparison process of step S4 is less than the switching judgment value Th1 (S4: No), the sensitivity setting unit 24 determines whether the duration T2 of the state in which the time difference DS is less than the threshold L1 has become equal to or greater than the recovery time TA1 (S5). If the duration T2 in the comparison process of step S5 is less than the recovery time TA1 (S5: No), the sensitivity setting unit 24 sets the detection sensitivity of the detection unit 22 to the second sensitivity (S6). If the duration T2 in the comparison process of step S5 is equal to or greater than the recovery time TA1 (S5: Yes), the sensitivity setting unit 24 sets the detection sensitivity of the detection unit 22 to the first sensitivity (S7).

[0075] When the detection sensitivity of the detection unit 22 is set to the first sensitivity or the second sensitivity, the detection unit 22, for example, calculates the time difference DS of the output signal at time intervals corresponding to the detection sensitivity, and compares the level of this time difference DS with the threshold L1 (S8).

[0076] In the comparison process in step S8, if the time difference DS is greater than or equal to the threshold L1 (S8: Yes), the detection unit 22 determines that a person is present in the detection target space SP1 and outputs a presence detection signal to the load control unit 23. When the load control unit 23 receives the presence detection signal from the detection unit 22, it outputs an ON control signal to the drive circuit 40. When the drive circuit 40 receives the ON control signal from the load control unit 23, it controls the switch element 41 to a conductive state and supplies power to the lighting load, which is load 3, to turn on the lighting load (S9).

[0077] On the other hand, if the time difference DS in the comparison process of step S7 is less than the threshold L1 (S8: No), the detection unit 22 determines that no person is present in the detection target space SP1 and outputs an absence detection signal to the load control unit 23. When the load control unit 23 receives the absence detection signal from the detection unit 22, it outputs an off control signal to the drive circuit 40. When the drive circuit 40 receives the off control signal from the load control unit 23, it controls the switch element 41 to a non-conductive state, cuts off the power supply to the lighting load, which is load 3, and turns off the lighting load (S10).

[0078] Here, we consider the case where a person 300 passes through room 400, as shown in Figure 9. Figure 10 is a graph showing the time change of the integrated value Sa of the time difference DS calculated by the sensitivity setting unit 24 of the motion detection system 1 when person 300 moves in this manner. In Figure 10, time t1 is when person 300 enters the detection area A1 of the radio wave sensor 10, and time t2 is when person 300 leaves the detection area A1 of the radio wave sensor 10. From time t1, the integrated value Sa gradually increases, and from time t2 onward, the integrated value Sa gradually decreases. However, since person 300 does not remain in the detection area A1, the integrated value Sa of the time difference DS is less than the switching judgment value Th1. Therefore, the sensitivity setting unit 24 sets the detection sensitivity of the detection unit 22 to the first sensitivity, which reduces the possibility of the detection unit 22 falsely detecting an object other than a person that is moving.

[0079] On the other hand, as shown in Figure 11, consider the case where a person 300 enters room 400, stops in the central area B1 of room 400 (for example, sits down on a chair in area B1), and then leaves room 400. Figure 12 is a graph showing the time change of the integrated value Sa of the time difference DS calculated by the sensitivity setting unit 24 of the motion detection system 1 when person 300 makes such movements. Time t11 in Figure 12 is when person 300 enters the detection area A1 of the radio wave sensor 10, and from time t11, the integrated value Sa gradually increases. Here, because person 300 performs the action of sitting down on a chair in area B1 within room 400, the integrated value Sa of the time difference DS rises to above the switching judgment value Th1. While the person remains in area B1, the person makes small movements such as breathing, so the integrated value Sa of the time difference DS remains above the switching judgment value Th1. Subsequently, when a person who was seated in a chair within area B1 stands up and moves outside of detection area A1, the cumulative value Sa of the time difference DS will gradually decrease.

[0080] When person 300 makes such movements, the sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the first sensitivity to the second sensitivity at time t12 when the accumulated value Sa of the time difference DS exceeds the switching judgment value Th1. Subsequently, when person 300 leaves the detection area A1 and at time t13 the accumulated value Sa of the time difference DS falls below the switching judgment value Th1, the sensitivity setting unit 24 switches the detection sensitivity of the detection unit 22 from the second sensitivity to the first sensitivity.

[0081] As a result, the sensitivity setting unit 24 can reduce the possibility of missing a person by setting the detection sensitivity of the detection unit 22 to the second sensitivity during the period from time t12 to time t13, when there is a high probability that a person is present in the detection area A1. Furthermore, during the period until the detection unit 22 detects an active person 300 (the period before time t12), and during the period after the person leaves the detection area A1 and the accumulated value Sa falls below the switching judgment value Th1 (the period after time t13), the sensitivity setting unit 24 sets the detection sensitivity of the detection unit 22 to the first sensitivity, thereby reducing the possibility of false detection of objects other than people. The sensitivity setting unit 24 may also switch the detection sensitivity from the second sensitivity to the first sensitivity from time t13, when the accumulated value Sa of the time difference DS falls below the switching judgment value Th1, to time t14, when the state in which the accumulated value Sa is below the switching judgment value Th1 continues for a recovery time TA1 or longer.

[0082] (3) Variant The above embodiments are merely one of many embodiments of this disclosure. The above embodiments can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. Furthermore, functions similar to those of the motion detection system 1 may be embodied in a motion detection method, a computer program, a non-temporary recording medium on which the program is recorded, or a computer program product including the program. A motion detection method according to one embodiment includes an acquisition process, a detection process, and a sensitivity setting process. In the acquisition process, an output signal output from the radio wave sensor 10 for each detection period is acquired. In each of the multiple detection periods, the radio wave sensor 10 transmits a transmission wave, which is a frequency-modulated radio wave, to the detection target space SP1. When the radio wave sensor 10 receives a reflected wave, which is the transmission wave reflected at the reflection point of an object present in the detection target space SP1, it outputs an output signal based on the transmission wave and the reflected wave. In the detection process, a time difference is calculated, which is the difference in the time difference intensity of two output signals output by the radio wave sensor 10 during two different detection periods, and the presence or absence of a moving object is detected based on the comparison result obtained by comparing the time difference with a threshold. In the sensitivity setting process, when a switching condition based on the time difference is met, the object detection sensitivity in the detection process is switched from the first sensitivity to a second sensitivity which is more sensitive than the first sensitivity. A (computer) program according to one embodiment is a program that causes one or more processors to execute the above motion detection method.

[0083] The following lists some modifications of the above embodiment. The modifications described below can be combined and applied as appropriate.

[0084] The entity that executes the motion detection system 1 and motion detection method in this disclosure includes a computer system. The computer system mainly consists of a processor and memory as hardware. The functions of the motion detection system 1 in this disclosure are realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided via a telecommunications line, or provided on a non-temporary recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. The processor of the computer system consists of one or more electronic circuits including semiconductor integrated circuits (ICs) or large-scale integrated circuits (LSIs). The integrated circuits such as ICs and LSIs referred to here are named differently depending on the degree of integration, and include integrated circuits called system LSIs, VLSIs (Very Large Scale Integration), or ULSIs (Ultra Large Scale Integration). Furthermore, FPGAs (Field-Programmable Gate Arrays) that are programmed after the manufacture of LSIs, or logic devices that allow for the reconfiguration of junction relationships or circuit compartments within LSIs, can also be used as processors. Multiple electronic circuits may be integrated onto a single chip or distributed across multiple chips. Multiple chips may be integrated onto a single device or distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller also consists of one or more electronic circuits, including semiconductor integrated circuits or large-scale integrated circuits.

[0085] Furthermore, it is not essential for the motion detection system 1 to have multiple functions integrated into a single housing 2, and the components of the motion detection system 1 may be distributed across multiple housings. Similarly, it is not essential for the wiring device 100 to have multiple functions integrated into a single housing 2, and the components of the wiring device 100 may be distributed across multiple housings.

[0086] The method by which the sensitivity setting unit 24 calculates the integrated value Sa of the time difference DS is not limited to the calculation method described in the above embodiment (a method of integrating the time difference over a predetermined integration period up to the current detection period). The sensitivity setting unit 24 may calculate the integrated value in the following way. Here, if the calculation result of the time difference obtained in the current frame is DS, the integrated value of the time difference obtained in the previous frame is Sb, and a predetermined constant subtraction value is M1, the sensitivity setting unit 24 may calculate the integrated value Sa in the current frame using the following formula (1).

[0087] Sa = DS + Sb - M1 …(1) The subtraction value M1 is set to a value smaller than the time difference caused by minute movements of a person (for example, breathing or shifting). Therefore, even if a person in the detection target space SP1 is standing still or sitting in a chair, if they are making minute movements such as breathing or shifting, the integrated value Sa calculated by the detection unit 22 will gradually increase. On the other hand, if a person who was in the detection target space SP1 moves outside of the detection target space SP1, the detection unit 22 will not be able to detect the person's movement, and the calculation result of the time difference DS will become zero, so the integrated value Sa will gradually decrease.

[0088] In the above embodiment, where "greater than or equal to" is used in the comparison of the magnitudes of two values, it may also be used as "greater than." In other words, whether or not the case where the two values ​​are equal is included in the comparison of two values ​​can be arbitrarily changed depending on the setting of the reference value, etc., so there is no technical difference between "greater than or equal to" and "greater than." Similarly, where "less than" is used, it may also be used as "less than or equal to."

[0089] In the above embodiment, the housing 2 of the wiring device 100 is located on the underside of the ceiling 401, but the housing 2 of the wiring device 100 may also be located on the wall 402 of the room 400. In this case, the radio wave sensor 10 only needs to be mounted on the housing 2 so as to transmit radio waves in the direction normal to the wall 402 on which the housing 2 is located, and it can detect objects present in the interior space of the room 400.

[0090] In the above embodiment, the motion detection system 1 is provided in the wiring device 100, but it may also be provided in a load system 200 such as a lighting device. The lighting device includes a main body that houses a light source and a lighting circuit for the light source, and the motion detection system 1 is housed inside the main body. The lighting circuit controls the operating state of the light source (e.g., on, off, dimming, etc.) according to the detection result of the motion detection system 1. Note that the load system 200 is not limited to a lighting device, but may also be an air conditioning device such as a ventilation fan or an air conditioner.

[0091] In the above embodiment, the radio wave sensor 10 is equipped with one transmitting antenna and three receiving antennas, but the number of receiving antennas may be two or four or more.

[0092] Furthermore, in the radio wave sensor 10, the antenna used for transmitting the transmitting wave Tr and the antenna used for receiving the receiving wave Re may be the same antenna (hereinafter referred to as the "common antenna"). In other words, the transmitting wave Tr may be transmitted from the common antenna, and the receiving wave Re corresponding to the transmitting wave Tr may be received by the same common antenna.

[0093] In the above embodiment, one transmission / reception operation is performed in one frame Fr, but multiple transmission / reception operations may be performed in one frame Fr. In that case, the detection unit 22 can detect the presence or absence of a moving object based on a representative value (e.g., an average value) of the IF signal output from the radio wave sensor 10 during multiple transmission / reception operations.

[0094] Alternatively, the motion detection system 1 may be housed in a separate enclosure and output the motion detection result to a wiring device 100 or a load system 200 (e.g., a lighting device).

[0095] (summary) Based on the embodiments described above, the following aspects are disclosed.

[0096] The first embodiment of the motion detection system (1) comprises a radio wave sensor (10), a detection unit (22), and a sensitivity setting unit (24). The radio wave sensor (10) transmits a frequency-modulated radio wave, which is a transmitted wave, to the detection target space (SP1) during each of a plurality of detection periods. When the radio wave sensor (10) receives a reflected wave, which is the transmitted wave reflected at the reflection point of an object present in the detection target space (SP1), it outputs an output signal based on the transmitted wave and the reflected wave. The detection unit (22) calculates a time difference, which is the difference in the output signal intensity of two output signals output by the radio wave sensor (10) during two different detection periods, and detects the presence or absence of a moving object based on the comparison result obtained by comparing the time difference with a threshold. When a switching condition based on the time difference is met, the sensitivity setting unit (24) switches the object detection sensitivity of the detection unit (22) from a first sensitivity to a second sensitivity that is more sensitive than the first sensitivity.

[0097] In this embodiment, when the switching condition based on the time difference is met, the sensitivity setting unit (24) switches the detection sensitivity of the detection unit (22) from the first sensitivity to the second sensitivity, which is more sensitive than the first sensitivity. Therefore, when the switching condition based on the time difference is not met, the detection sensitivity of the detection unit (22) can be set to the first sensitivity, which is lower than the second sensitivity, thereby suppressing false detections.

[0098] In the second embodiment of the motion detection system (1), in the first embodiment, the detection unit (22) determines the distribution of one or more reflection points whose time difference is greater than or equal to a threshold, and detects the position of a moving object based on the distribution.

[0099] According to this embodiment, the position of a moving object can be determined based on the distribution of one or more reflection points.

[0100] In the third embodiment of the motion detection system (1), in the second embodiment, the detection unit (22) detects the movement of an object corresponding to a distribution based on the temporal displacement of the distribution.

[0101] According to this embodiment, the detection unit (22) can detect the movement of an object based on the temporal displacement of the distribution of one or more reflection points.

[0102] In the fourth embodiment of the motion detection system (1), in any of the first to third embodiments, the switching condition includes a condition relating to an integrated value obtained by accumulating multiple time differences calculated for each of the multiple detection periods.

[0103] According to this embodiment, the detection sensitivity can be switched based on an integrated value obtained by accumulating multiple time differences, that is, an integrated value obtained by accumulating the displacement of an object.

[0104] In the fifth embodiment of the motion detection system (1), in the fourth embodiment, the condition relating to the cumulative value includes the condition that the cumulative value is equal to or greater than the switching judgment value.

[0105] According to this embodiment, when the accumulated value is greater than or equal to the switching judgment value, that is, when the object has made a large movement, the detection sensitivity of the detection unit (22) can be switched from the first sensitivity to the second sensitivity.

[0106] In the sixth embodiment of the motion detection system (1), in any of the first to fifth embodiments, the sensitivity setting unit (24) switches the detection sensitivity of the detection unit (22) to the second sensitivity, and then, if the state in which the detection unit (22) does not detect a moving object continues for longer than the recovery time, the detection sensitivity of the detection unit (22) is switched from the second sensitivity to the first sensitivity.

[0107] According to this embodiment, false detections can be suppressed by the sensitivity setting unit (24) switching the detection sensitivity of the detection unit (22) to a first sensitivity.

[0108] In the seventh embodiment of the motion detection system (1), in any of the first to sixth embodiments, the sensitivity setting unit (24) adjusts the detection sensitivity of the detection unit (22) by adjusting the time interval between two output signals used to calculate the time difference. The sensitivity setting unit (24) makes the time interval for setting the detection sensitivity to the second sensitivity longer than the time interval for setting the detection sensitivity to the first sensitivity.

[0109] According to this embodiment, the detection sensitivity of the detection unit (22) can be adjusted by adjusting the time interval between the two output signals.

[0110] In the eighth embodiment of the motion detection system (1), in any of the first to seventh embodiments, the sensitivity setting unit (24) adjusts the detection sensitivity of the detection unit (22) by adjusting the value of a threshold. The sensitivity setting unit (24) makes the threshold value for setting the detection sensitivity to the second sensitivity smaller than the threshold value for setting the detection sensitivity to the first sensitivity.

[0111] According to this embodiment, the detection sensitivity of the detection unit (22) can be adjusted by adjusting the threshold value.

[0112] The motion detection system (1) of the ninth embodiment further comprises a housing (2) in any of the first to eighth embodiments. The housing (2) houses a radio wave sensor (10) and is positioned on a wall (402) next to the space to be detected (SP1) or on the ceiling (401) above the space to be detected (SP1).

[0113] According to this embodiment, the presence or absence of an object in the target space (SP1) can be detected using a radio wave sensor (10) housed in a housing (2) positioned on a wall (402) or ceiling (401).

[0114] In the tenth embodiment of the motion detection system (1), in the ninth embodiment, the housing (2) further houses the detection unit (22).

[0115] According to this embodiment, compared to the case where the radio wave sensor (10) and the detection unit (22) are housed in separate enclosures, the installation work for the radio wave sensor (10) and the detection unit (22) can be performed at one time, thereby simplifying the installation work.

[0116] The wiring device (100) of the eleventh embodiment comprises a motion detection system (1) of any of the first to tenth embodiments, a load connection section (50), and a load control section (23). A load (3) is connected to the load connection section (50). The load control section (23) controls the operating state of the load (3) connected to the load connection section (50) based on the object detection result by the motion detection system (1).

[0117] According to this embodiment, false detections can be reduced.

[0118] The twelfth embodiment of the load system (200) comprises a motion detection system according to any of the first to tenth embodiments, a load (3), and a load control unit (23). The load control unit (23) controls the operating state of the load (3) based on the object detection result by the motion detection system (1).

[0119] According to this embodiment, false detections can be reduced.

[0120] The motion detection method of the 13th embodiment includes an acquisition process, a detection process, and a sensitivity setting process. In the acquisition process, an output signal output from the radio wave sensor (10) is acquired for each detection period. In each of the multiple detection periods, the radio wave sensor (10) transmits a frequency-modulated radio wave, which is a transmitted wave, to the detection target space (SP1). When the radio wave sensor (10) receives a reflected wave, which is the reflection of the transmitted wave at the reflection point of an object present in the detection target space (SP1), it outputs an output signal based on the transmitted wave and the reflected wave. In the detection process, the time difference, which is the difference in the output signal intensity of two output signals output by the radio wave sensor (10) during two different detection periods, is calculated, and the presence or absence of a moving object is detected based on the comparison result obtained by comparing the time difference with a threshold. In the sensitivity setting process, when the switching condition based on the time difference is met, the object detection sensitivity in the detection process is switched from the first sensitivity to a second sensitivity which is more sensitive than the first sensitivity.

[0121] In this embodiment, when the switching condition based on the time difference is met, the detection sensitivity of the detection unit (22) is switched from the first sensitivity to the second sensitivity, which is more sensitive than the first sensitivity, during the sensitivity setting process. Therefore, when the switching condition based on the time difference is not met, the detection sensitivity of the detection unit (22) can be set to the first sensitivity, which is lower than the second sensitivity, thereby suppressing false detections.

[0122] The program of the 14th embodiment is a program for causing one or more processors to execute the motion detection method of the 13th embodiment.

[0123] According to this embodiment, false detections can be reduced.

[0124] Not limited to the above embodiments, various configurations (including modifications) of the motion detection system (1) according to the above embodiment can be embodied in motion detection methods, (computer) programs, non-temporary recording media on which the program is recorded, or computer program products including the program, etc., which are executed by the motion detection system (1).

[0125] The configurations relating to the second to tenth aspects are not essential to the motion detection system (1) and can be omitted as appropriate. [Explanation of Symbols]

[0126] 1. Motion detection system 2 cabinets 3 load 10 Radio wave sensors 22 Detection unit 23 Load Control Unit 24 Sensitivity setting section 50 Load connection section 100 Wiring Devices 200 load system 401 Ceiling 402 Wall SP1 Detection Target Space

Claims

1. A radio wave sensor that transmits a frequency-modulated radio wave, which is a transmitted wave, to the detection target space during each of multiple detection periods, and receives a reflected wave from the reflection point of an object present in the detection target space, outputs an output signal based on the transmitted wave and the reflected wave. Detection unit, It includes a sensitivity setting unit, The detection unit calculates a time difference, which is the difference in the output signal intensity of the two output signals output by the radio wave sensor during two different detection periods, and detects the presence or absence of a moving object based on the comparison result obtained by comparing the time difference with a threshold. When the switching condition based on the time difference is met, the sensitivity setting unit switches the object detection sensitivity of the detection unit from the first sensitivity to a second sensitivity which is more sensitive than the first sensitivity. Motion detection system.

2. The detection unit determines the distribution of one or more reflection points whose time difference is greater than or equal to the threshold, and detects the position of the moving object based on the distribution. The motion detection system according to claim 1.

3. The detection unit detects the movement of the object corresponding to the distribution based on the temporal displacement of the distribution. The motion detection system according to claim 2.

4. The switching conditions include conditions relating to the cumulative value obtained by accumulating the multiple time differences calculated for each of the multiple detection periods, The motion detection system according to claim 1.

5. The conditions relating to the cumulative value include the condition that the cumulative value is equal to or greater than the switching determination value. The motion detection system according to claim 4.

6. The sensitivity setting unit, after switching the detection sensitivity of the detection unit to the second sensitivity, switches the detection sensitivity of the detection unit from the second sensitivity to the first sensitivity if the state in which the detection unit does not detect a moving object continues for a period longer than the recovery time. The motion detection system according to claim 1.

7. The sensitivity setting unit adjusts the detection sensitivity by adjusting the time interval between the two output signals used to calculate the time difference, making the time interval when the detection sensitivity is set to the second sensitivity longer than the time interval when the detection sensitivity is set to the first sensitivity. The motion detection system according to claim 1.

8. The sensitivity setting unit adjusts the detection sensitivity by adjusting the value of the threshold, making the threshold for the second detection sensitivity smaller than the threshold for the first detection sensitivity. The motion detection system according to claim 1.

9. The system further comprises a housing for the radio wave sensor, which is positioned on a wall adjacent to the space to be detected, or on the ceiling above the space to be detected. The motion detection system according to claim 1.

10. The housing further houses the detection unit, The motion detection system according to claim 9.

11. A motion detection system according to any one of claims 1 to 10, A load connection section to which the load is connected, The system includes a load control unit that controls the operating state of the load connected to the load connection unit based on the detection result of the object by the motion detection system, Wiring devices.

12. A motion detection system according to any one of claims 1 to 10, Load and The system includes a load control unit that controls the operating state of the load based on the detection result of the object by the motion detection system, Load system.

13. In each of the multiple detection periods, a transmission wave, which is a frequency-modulated radio wave, is transmitted to the detection target space, and when the transmitted wave is received from the reflection point of an object present in the detection target space, an acquisition process is performed to acquire the output signal output for each detection period from a radio wave sensor that outputs an output signal based on the transmitted wave and the reflected wave. Detection process, This includes sensitivity setting processing, In the detection process, the time difference, which is the difference in the output signal intensity of the two output signals output by the radio wave sensor during two different detection periods, is calculated, and the presence or absence of a moving object is detected based on the comparison result obtained by comparing the time difference with a threshold. In the sensitivity setting process, when the switching condition based on the time difference is met, the detection sensitivity of the object in the detection process is switched from a first sensitivity to a second sensitivity which is more sensitive than the first sensitivity. Motion detection method.

14. One or more processors are used to perform the motion detection method described in claim 13, program.

Images