Organism detection device

Abstract

To provide an organism detection device that can improve accuracy of detecting organisms in a vehicle.SOLUTION: An organism detection device includes at least one radar and an ECU. The radar is mounted on a vehicle, transmits pulse waves of a predetermined frequency, and receives reflected waves of the pulse waves. The radar transmits and receives the waves multiple times at predetermined intervals. A reception time of the reflected wave is longer than a time corresponding to the distance between the radar and the most distant position from the radar at the edge of the vehicle. The ECU detects presence or absence of an organism based on the received signals in the multiple transmissions and receptions.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The disclosure herein relates to a biosensing device. [Background technology]

[0002] Patent Document 1 discloses an occupant detection device equipped with a radar that transmits pulse waves and receives reflected waves. The contents of the prior art documents are incorporated by reference as explanations of technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-181225 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of a living body detection device using a pulse wave, there is a problem in that the accuracy of detecting a living body is low. In the above-mentioned respects and in other respects not mentioned, further improvement of the living body detection device is required.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a living body detection device that can improve the accuracy of detecting a living body inside a vehicle. [Means for solving the problem]

[0006] In the case of a living body detection device using a pulse wave, transmission and reception are performed multiple times at a predetermined interval to detect the presence or absence of a living body. As a result of careful consideration, it was found that multiple transmissions and receptions cause a time lag in the received waveform, i.e., sampling variation, and the fluctuation caused by the living body is buried in the change caused by the sampling variation, and there is a risk that the living body cannot be detected. The disclosed living body detection device is based on this knowledge.

[0007] A biological detection device according to one embodiment of the present disclosure includes: At least one radar (30) mounted on a vehicle (10), transmitting pulse waves of a predetermined frequency and receiving reflected waves of the pulse waves; a detection unit (40) for detecting the presence or absence of a living body inside the vehicle based on a received signal from the radar; Equipped with The radar transmits and receives signals multiple times at predetermined intervals. The reception time of the reflected wave is longer than the time corresponding to the distance between the radar and the farthest position from the radar at the end of the vehicle, The detection unit detects the presence or absence of a living body based on the received signals from multiple transmissions and receptions.

[0008] According to the disclosed living body detection device, transmission and reception are performed multiple times, and the presence or absence of a living body is detected based on the multiple received signals. By lengthening the reception time, the radar receives indirect waves from the living body via the metal object of the vehicle. In this way, multipath is actively utilized. Even if sampling variations occur due to indirect waves that are received with a delay compared to the direct waves from the metal object, the presence or absence of a living body can be detected. This makes it possible to improve the accuracy of detecting a living body inside the vehicle.

[0009] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference characters in parentheses in the claims, this section, and the technical idea section are illustrative of the corresponding relationship with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the following detailed description and the attached drawings. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram illustrating a detection principle. [Diagram 2] FIG. 2 is a diagram showing an example of a radar received waveform. [Diagram 3] FIG. 4 is a diagram showing temporal variations in the reception strength of a reflected wave. [Figure 4] FIG. 2 is a diagram showing a mounting position of a radar on a vehicle. [Diagram 5] FIG. 13 is a diagram showing the results of measuring reflection intensity. [Figure 6] FIG. 6 is a diagram in which the time shown in FIG. 5 is replaced with distance. [Figure 7] 13 is a diagram showing the time variation of the reception strength of the reflected wave when a child is present in the P seat. FIG. [Figure 8] FIG. 8 is a diagram showing a waveform obtained by subjecting the waveform of FIG. 7 to filtering. [Figure 9] FIG. 13 is a diagram showing sampling variations in multiple transmissions and receptions. [Figure 10] FIG. 13 is a diagram showing temporal variations in the reception strength of reflected waves when a child is present in the trunk. [Figure 11] FIG. 11 is a diagram showing a waveform obtained by subjecting the waveform of FIG. 10 to filtering. [Figure 12] 1 is a diagram showing a biological detection device according to a first embodiment. [Figure 13] FIG. 13 is a diagram showing an indirect wave passing from a living body through a metal body. [Figure 14] 13 is a flowchart showing a living body detection process. [Figure 15] FIG. 13 is a diagram showing temporal fluctuations of reception strength at sampling point SP1. [Figure 16] FIG. 16 is a diagram showing a waveform obtained by subjecting the waveform of FIG. 15 to filtering. [Figure 17] 10 is a flowchart showing a living body detection process executed by a living body detection device according to a second embodiment. [Figure 18] 13 is a flowchart showing a living body detection process executed by a living body detection device according to a third embodiment. [Figure 19] FIG. [Figure 20] 13 is a flowchart showing a living body detection process executed by a living body detection device according to a fourth embodiment. [Figure 21] FIG. 1 is a diagram illustrating an example of the displacement of a moving object relative to a radar. [Figure 22] FIG. 13 is a diagram showing a change in relative velocity. [Diagram 23] FIG. 13 is a diagram showing an example of radar arrangement in a living body detection device according to a fifth embodiment. [Figure 24] 13 is a flowchart showing a living body detection process. [Diagram 25] FIG. 2 is a diagram showing received waveforms of one pulse from an in-vehicle radar and an external radar. [Figure 26] FIG. 13 is a diagram showing an example of mounting positions of a plurality of radars on a vehicle in a living body detection device according to a sixth embodiment. [Figure 27] FIG. 13 is a diagram showing a living body detection process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, several embodiments will be described with reference to the drawings. In addition, by assigning the same reference numerals to corresponding components in each embodiment, duplicated explanations may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. In addition to the combination of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0012] (First embodiment) As an in-car occupant sensing app, child abandonment detection will be added to EuroNCAP from 2023 and will be eligible for additional points. In particular, it has been decided that from 2025 onwards, only systems that directly detect whether a child has been left behind will be subject to evaluation. EuroNCAP is an abbreviation for European New Car Assessment Program.

[0013] For this reason, it is necessary to detect biological information such as breathing and body movements throughout the vehicle to determine whether a child is present. One of the evaluation conditions is that it is necessary to detect whether the child is covered with a blanket or in a child seat, which is difficult to do using a camera, and so the use of radio waves is considered the most promising method.

[0014] The living body detection device according to this embodiment detects the presence or absence of a living body in a vehicle by using a pulse wave as described below. The living body detection device can be applied to, for example, detection of a child left behind. A living body in a vehicle that can be detected by the living body detection device is not limited to a child, but may include passengers other than a child, animals such as a dog or a cat, etc.

[0015] First, the principle of detecting a living body using a pulse wave as an electric wave will be described with reference to Figs.

[0016] <Detection principle> FIG. 1 shows the detection principle. FIG. 1 shows the displacement of the body surface due to breathing. In FIG. 1, the transmitted pulse wave (transmitted wave) is shown by a solid arrow, the reflected wave by the human body is shown by a dashed arrow, and the transmitted wave passing through the human body is shown by a two-dot chain arrow. FIG. 2 shows an example of a radar received waveform. FIG. 3 shows the time variation of the reception strength of the reflected wave. FIG. 3 shows the time change of the reception strength during multiple transmissions and receptions. Here, a human body is shown as an example of the living body 100.

[0017] As shown in FIG. 1, when a high-frequency pulse wave is irradiated from the radar 30 to a living body 100 (human body), a part of the pulse wave passes through the living body 100, and another part is reflected by the body surface 100s. The high-frequency wave is, for example, a frequency of 1 GHz or higher. The radar 30 is, for example, a UWB radar. UWB is an abbreviation for Ultra Wide Band. Since the body surface 100s is displaced by breathing, the distance between the radar 30 (antenna) and the living body 100 changes in response to breathing. The displacement Δd of the body surface 100s due to breathing is, for example, about 1 mm to 10 mm.

[0018] Therefore, the reception strength of the reflected wave changes according to respiration as shown by the arrow in Fig. 2. Fig. 2 shows a received waveform at a specified transmission / reception timing. By monitoring the received waveforms of multiple transmissions and receptions, a waveform showing the time variation of the reception strength of the reflected wave shown in Fig. 3 can be obtained. The time variation shown in Fig. 3 is specific to the respiration of the living body 100. Therefore, the presence or absence of a living body can be detected using the time variation. Body movement can also be detected by monitoring the received waveform because the distance between the radar 30 and the living body 100 changes.

[0019] <Sampling variation> FIG. 4 shows the mounting position of the radar (UWB radar) when the reflection intensity was measured. FIG. 5 shows the result of measuring the reflection intensity. FIG. 6 shows the time shown in FIG. 5 replaced with distance. For convenience, FIG. 6 shows half the distance (round-trip distance) corresponding to the reception intensity as the distance, that is, the one-way distance. FIG. 7 shows the time variation of the reception intensity of the reflected wave when a child (living body) is present in seat P. FIG. 7 corresponds to FIG. 3. FIG. 7 shows the time variation of the reception intensity when a child is present at distance L1. FIG. 8 shows the waveform of FIG. 7 after filtering. FIG. 8 shows the waveform after frequency filtering (0.1 to 1 Hz). FIG. 9 shows the sampling variation in multiple transmissions and receptions.

[0020] As shown in Fig. 4, when measuring the reflection intensity, the radar 30 was placed near the front end of the vehicle ceiling and near the center in the left-right direction, specifically on the overhead console. The received waveform in Fig. 5 shows the waveform (base waveform) when no living body is present inside the vehicle. The time on the horizontal axis shows the elapsed time from the transmission of the pulse wave to the reception of the reflected wave, that is, the reception time. As shown in Fig. 5, the area where the reception intensity is high near the time of zero (0) is due to reflection (direct wave) from the metal ceiling. Reflections from not only the ceiling but also metal objects such as the body are superimposed on the received waveform depending on the distance from the radar 30. In areas where the reception time is short, the influence of the direct wave from the metal object is large, and the reception intensity is high.

[0021] When detecting the presence or absence of a living body inside the vehicle, for example, the presence or absence of a child, it is conceivable to monitor the received signal strength corresponding to the distance between each seat where a child may be present and the radar 30. In this case, as shown in FIG. 6, time is converted into distance, and fluctuations at locations corresponding to the distances from the radar 30 to each seat are detected. There is a relationship expressed by the following Equation 1 between the distance shown in FIG. 6 (one-way distance) and the time Δt from the transmission to the reception of the pulse wave. c is the speed of light (3×10 8 m / s). Twice the one-way distance is the round-trip distance. One-way distance × 2 = c × Δt ··· (Equation 1)

[0022] The dashed-dotted line shown in FIG. 6 indicates the positions of the front seats (D seat, P seat), rear seats (behind the D seat, behind the P seat), and the trunk. The front seats are located at a distance L1 from the radar 30. The rear seats are located at a distance L2 from the radar 30. The trunk is located at a distance L3 from the radar 30. The distances L1, L2, and L3 satisfy the relationship L1 < L2 < L3. The D seat is the driver's seat, and the P seat is the passenger seat.

[0023] However, it has been clarified that even if a child is present in the front seat, as shown in FIGS. 7 and 8, waveforms corresponding to breathing cannot be detected. The reason why detection is not possible at positions close to the radar 30, such as the D seat and the P seat, is due to the sampling variation of the radar 30. In multiple transmissions and receptions, a time shift on the order of ns occurs in the received waveform as exemplified in FIG. 9. For this reason, variations occur in the base received signal strength at a predetermined sampling point.

[0024] This variation has a greater impact as the received signal strength is greater. For example, when a child is present in a seat corresponding to a location where the influence of reflection from the ceiling remains (for example, the front seat), minute fluctuations such as breathing are buried in the change in the received signal strength due to sampling variation. Thus, it has become clear that there is a risk that variations caused by a living body are buried in variations due to sampling variation, and the living body cannot be detected.

[0025] Figure 10 shows the time variation in the reception strength of the reflected wave when there is a child in the trunk. Figure 10 corresponds to Figure 3. Figure 10 shows the time variation in the reception strength when there is a child at distance L3. Figure 11 shows the waveform after filtering has been applied to Figure 10. Like Figure 8, Figure 11 shows the waveform after frequency filtering (0.1 to 1 Hz).

[0026] Even when a child is present in the trunk, no waveforms corresponding to breathing could be detected, as shown in Figures 10 and 11. The trunk is located away from the radar 30, and there are obstacles such as seats on the straight line from the radar 30 to the trunk. This is thought to cause radio wave attenuation, making breathing detection difficult.

[0027] The living body detection device according to this embodiment is based on the above findings. Next, a schematic configuration of the living body detection device will be described.

[0028] <Biodetection device> Fig. 12 shows a schematic configuration of a living body detection device according to this embodiment. Fig. 13 shows an indirect wave. As shown in Fig. 12, the living body detection device 20 includes at least one radar 30 and an ECU 40. ECU is an abbreviation for Electronic Control Unit. The ECU 40 is sometimes called an electronic control device.

[0029] The radar 30 transmits a pulse wave of a predetermined frequency and receives a reflected wave of the pulse wave. The radar 30 has an antenna 31. The antenna 31 may include a transmitting antenna and a receiving antenna, or may include an antenna for both transmitting and receiving. The frequency of the pulse wave is a high frequency, for example, a frequency of 1 GHz or more, as described above. The radar 30 is a UWB radar or a millimeter wave radar. As an example, the radar 30 of this embodiment is an IR type UWB radar. IR is an abbreviation for Impulse Radio. The impulse signal used in UWB communication may be a signal having a very short pulse width (for example, 2 ns) and a bandwidth of 500 MHz (strictly speaking, 499.2 MHz) or more, that is, an ultra-wide bandwidth.

[0030] The radar 30 is attached to the vehicle 10. The living body detection device 20 may include only one radar 30, or may include multiple radars 30. As an example, the living body detection device 20 of this embodiment includes only one radar 30. As shown in Figures 4 and 13, the radar 30 is disposed inside the vehicle near the front end of the ceiling 11 and near the center in the left-right direction. The radar 30 is disposed in the overhead console. The radar 30 may be used in combination with a radar of a smart entry system, for example. The antenna 31 may be, for example, an omnidirectional antenna.

[0031] The radar 30 performs transmission and reception multiple times at a predetermined interval during a living body detection period described later. The radar 30 performs transmission and reception multiple times at a time interval that is sufficiently short with respect to the breathing cycle. The reception time of the reflected wave is longer than the time corresponding to the distance between the radar 30 and the position at the end of the vehicle 10 that is the furthest from the radar 30. Therefore, as shown in FIG. 13, the radar 30 receives an indirect wave that passes from the living body via the metal body of the vehicle 10. In this way, the living body detection device 20 actively uses multipath. As an example, in this embodiment, the vehicle 10 is a five-seater passenger car. The end of the vehicle 10 that is the furthest from the radar 30 is the rear end of the vehicle, and the distance from the radar 30 to the rear end of the vehicle is about 2 m. The reception time of the reflected wave is longer than the time corresponding to the distance of 2 m to the rear end of the vehicle. The reception time may be, for example, a time (about 13 ns) corresponding to a round-trip distance of 4 m between the radar 30 and the rear end of the vehicle. The radar 30 may perform the next transmission and reception after 100 ms has elapsed after the previous transmission and reception.

[0032] The ECU 40 controls the operation of the radar 30. The ECU 40 detects the presence or absence of a living body inside the vehicle based on a signal received by the radar 30. The ECU 40 corresponds to a detection unit. The ECU 40 detects the presence or absence of a living body based on a plurality of received signals. As an example, the ECU 40 of this embodiment detects the presence or absence of a living body based on the amount of time variation of a plurality of received signals. The ECU 40 is configured to include a processor 41, a memory 42, and a storage 43.

[0033] The processor 41 executes various processes by accessing the memory 42. The memory 42 is a rewritable volatile storage medium. The memory 42 is, for example, a RAM. RAM is an abbreviation for Random Access Memory. The storage 43 is a rewritable non-volatile storage medium. The storage 43 stores programs executed by the processor 41. The ECU 40 executes the programs while accessing the memory to construct multiple functional units. The execution of the programs by the processor 41 corresponds to the execution of a living body detection method described below. The ECU 40 may include multiple processors 41. The ECU 40 may also be used as an ECU for a smart entry system, for example. The ECU 40 may include a function for detecting the presence or absence of a living body in the vehicle together with the radar 30, for example, a function for detecting whether a child has been left behind.

[0034] <Body detection method> 14 is a flowchart showing the process executed by the living body detection device, that is, the living body detection method. When the doors of the vehicle 10 are locked, for example, the living body detection device 20 executes the living body detection process shown in FIG.

[0035] The ECU 40 controls the operation of the radar 30 so as to execute the transmission and reception process for a predetermined period (step S10). As a result, the radar 30 executes the transmission and reception process. In this embodiment, as an example, the predetermined period is set to 10 seconds from the door lock. During the predetermined period, the radar 30 repeatedly executes multiple transmissions and receptions at predetermined intervals. As described above, the reception time for one transmission is set to 13 ns, and multiple transmissions and receptions are performed at intervals of 100 ms.

[0036] Next, the ECU 40 acquires a plurality of received signals from the radar 30 during the predetermined period, and starts loop processing (step S20). The ECU 40 executes the loop processing sequentially for preset sampling points. The sampling points are, for example, predetermined distance values ​​shown in FIG. 6, or predetermined time values ​​shown in FIG. 5. A plurality of sampling points may be set for each predetermined distance or each predetermined time. The sampling points may be set, for example, every 0.1 m, or every 1 ns. The sampling points may be set based on data obtained by a test or the like.

[0037] The ECU 40 calculates the time variation of the reception strength at a predetermined sampling point, i.e., the amplitude (step S30). Next, the ECU 40 compares the calculated amplitude with a threshold value, and determines whether the amplitude is greater than the threshold value (step S40). As described above, the reception strength of the base waveform is generally greater the closer it is to the radar 30. The threshold value is set according to the sampling point. The threshold value is set according to the amplitude of the base waveform. The threshold value is set taking into consideration sampling variation, i.e., variation in the reception strength of the base waveform. This makes it possible to suppress erroneous judgments.

[0038] If the amplitude is equal to or less than the threshold, the ECU 40 executes the processes of steps S30 and S40 for the next sampling point. If the amplitude is equal to or less than the threshold for all sampling points, the ECU 40 ends the loop process (step S50). Next, the ECU 40 determines that the living body 100 is not present inside the vehicle (step S60) and ends the series of processes. If the amplitude is greater than the threshold in step S40, the ECU 40 determines that breathing or body movement is superimposed on the base waveform, that is, the living body 100 is present inside the vehicle (step S70) and ends the series of processes.

[0039] The ECU 40 detects the presence or absence of the living body 100 based on the time variation of the reception strength at the sampling point. As described above, the direct wave from the metal object such as the ceiling 11 is superimposed on the sampled reflected wave immediately after transmission. Therefore, the variation such as respiration is easily buried in the change of reception strength caused by the sampling variation.

[0040] On the other hand, when sampling the reflected wave after a certain time has passed since transmission, the influence of the direct wave by the metal object has weakened, and a waveform is observed in which the reflected wave from the living body 100 is further diffusely reflected inside the vehicle body and reaches the radar 30. The indirect wave that passes from the living body 100 through the metal object reaches the radar 30 later than the direct wave from the metal object. Therefore, fluctuations such as respiration are more likely to appear compared to points where the reflection strength of the base waveform is high.

[0041] FIG. 15 shows the time variation of the reception intensity at the sampling point SP1 shown by the two-dot chain line in FIG. 6. FIG. 15 corresponds to FIG. 3. FIG. 16 shows the waveform after filtering of FIG. 15. Like FIG. 8, FIG. 16 shows the waveform after frequency filtering (0.1 to 1 Hz). The sampling point SP1 is at a distance, for example 2.4 m, longer than the distance of 2 m to the rear end of the vehicle. The distance of the sampling point SP1 is longer than twice the distance of the front seat (distance L1). The ECU 40 includes the sampling point SP1 as a sampling point. As shown in FIG. 16, at the sampling point SP1, the influence of the direct wave from the metal body is weakened, and an indirect wave passing through the metal body from the living body 100 is observed. In FIG. 16, the variation due to breathing appears as an amplitude.

[0042] Furthermore, in a location away from the radar 30, such as the trunk, the direct wave may attenuate as described above and may not reach the living body 100 present in the trunk. However, the pulse wave may reach the living body 100 via a reflection path from the floor, and the reflected wave from the living body 100 may be diffused within the vehicle body and reach the radar 30. Therefore, as described above, at the sampling point where the influence of the direct wave from the metal body is weakened, it is possible to detect fluctuations due to breathing, etc.

[0043] <Summary of the First Embodiment> In this embodiment, attention is paid to the fact that the reflected wave that hits the living body (occupant) is superimposed on the received waveform of the radar 30 while being delayed in the time direction along various paths inside the vehicle. According to the living body detection device 20 of this embodiment, the radar 30 executes transmission and reception multiple times, and the ECU 40 (detection unit) detects the presence or absence of the living body 100 based on the multiple received signals. In each transmission and reception, the reception time of the reflected wave is longer than the time corresponding to the distance between the radar 30 and the position at the end of the vehicle 10 that is farthest from the radar 30. By lengthening the reception time, the radar 30 receives an indirect wave that passes from the living body 100 through a metal body of the vehicle 10. In this way, multipath is actively utilized.

[0044] At the sampling point where the indirect wave is superimposed, the influence of the direct wave from the metal object is small, and for example, the reception strength of the base waveform is low. Therefore, even if a time lag of the order of nanoseconds occurs in multiple receptions, that is, sampling variations occur, as illustrated in Fig. 9, the presence or absence of the living body 100 can be detected. Therefore, the detection accuracy of the living body 100 in the car can be improved. For example, the accuracy of detecting whether a child has been left behind can be improved.

[0045] The ECU 40 may detect the presence or absence of the living body 100 based on the time variation of the reception strength in multiple receptions, that is, the amplitude. Fluctuations such as respiration and body movement are superimposed on the base waveform. That is, the amplitude increases by the amount of respiration and body movement. Therefore, the presence or absence of the living body 100 can be detected based on the amplitude. By using the amplitude, it is possible to detect not only respiration but also fluctuations due to body movement.

[0046] A UWB radar may be used as the radar 30. In recent years, there has been a growing market need to use smartphones as car keys. One method of this is UWB, which uses radio waves compressed into a pulse shape to measure the communication time between the smartphone and the car to identify the smartphone's location and use this as a trigger for opening and closing the car key and starting the engine. By using a UWB radar, it can be used in combination with a smart entry system, reducing costs. There is no need to install a separate sensing radar. A millimeter wave radar may be used instead of the UWB radar.

[0047] Second embodiment This embodiment is a modification of the previous embodiment as a basic form, and the description of the previous embodiment can be used. In the previous embodiment, the presence or absence of a living body is detected based on the amplitude. Instead of this, the presence or absence of a living body may be detected based on the frequency characteristic.

[0048] Fig. 17 shows the process executed by the living body detection device according to this embodiment, that is, the living body detection method. In the living body detection process shown in Fig. 17, the processes of steps S130 and S140 are different from the processes of steps S30 and S40 shown in Fig. 14. The other processes are the same as those shown in Fig. 14.

[0049] For example, when the doors of the vehicle 10 are locked, the living body detection device 20 executes the living body detection process shown in FIG. 17. The processes of steps S110 and S120 are similar to the processes of steps S10 and S20 shown in FIG. 14. In the loop process, the ECU 40 calculates the frequency characteristic (step S130). The ECU 40 calculates the frequency characteristic based on, for example, the time fluctuation of the reception strength at a predetermined sampling point. The ECU 40 calculates the frequency characteristic by using a fast Fourier transform (FFT) on the time fluctuation (amplitude) of the reception strength. The ECU 40 calculates, for example, kurtosis as the frequency characteristic. The kurtosis is obtained by dividing the reception strength at the peak frequency by the average strength of the other frequencies.

[0050] Next, the ECU 40 compares the calculated kurtosis with a threshold value and determines whether the kurtosis is greater than the threshold value (step S140). If the kurtosis is equal to or less than the threshold value, the ECU 40 executes the processes of steps S130 and S140 for the next sampling point. If the kurtosis is equal to or less than the threshold value for all sampling points, the ECU 40 ends the loop process (step S150), determines that the living body 100 is not present in the vehicle (step S160), and ends the series of processes. The process of step S150 is the same as the process of step S50. The process of step S160 is the same as the process of step S60.

[0051] In step S140, if the kurtosis is greater than the threshold, the ECU 40 detects breathing, that is, determines that the living body 100 is present inside the vehicle (step S170), and ends the series of processes. The process of step S170 is the same as the process of step S70. The other configurations are the same as those described in the preceding embodiment.

[0052] <Summary of the second embodiment> According to this embodiment, it is possible to obtain the same effect as the preceding embodiment. For example, even if a time lag of the order of ns occurs in multiple receptions, that is, sampling variations occur, it is possible to detect the presence or absence of the living body 100. Therefore, it is possible to improve the detection accuracy of the living body 100 in the vehicle.

[0053] The ECU 40 may detect the presence or absence of the living body 100 based on the frequency characteristics of the signal received multiple times. The presence or absence of the living body 100 can be detected based on whether or not the frequency characteristics are specific to breathing.

[0054] Third embodiment This embodiment is a modification based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, the presence or absence of a living body is detected based on the amplitude or frequency characteristics. Instead, the presence or absence of a living body may be detected based on the amplitude and frequency characteristics.

[0055] Fig. 18 shows a process executed by the living body detection device according to this embodiment, that is, a living body detection method. The living body detection process shown in Fig. 18 is configured by adding steps S130 and S140 in Fig. 17 to the process shown in Fig. 14.

[0056] For example, when the doors of the vehicle 10 are locked, the living body detection device 20 executes the living body detection process shown in FIG. 18. The processes of steps S210, S220, S230, and S240 are similar to the processes of steps S10, S20, S30, and S40 shown in FIG. 14. If the amplitude is equal to or less than the amplitude threshold in step S240, the ECU 40 calculates the frequency characteristic (step S250). The ECU 40 calculates, for example, kurtosis as the frequency characteristic. Next, the ECU 40 determines whether the kurtosis is greater than the kurtosis threshold (step S260). The processes of steps S250 and S260 are similar to the processes of steps S130 and S140 shown in FIG. 17.

[0057] If the kurtosis is equal to or less than the threshold, the ECU 40 executes the process from step S230 onwards for the next sampling point. If the amplitude is equal to or less than the amplitude threshold and the kurtosis is equal to or less than the kurtosis threshold for all sampling points, the ECU 40 ends the loop process (step S270), determines that the living body 100 is not present in the vehicle (step S280), and ends the series of processes. The processes of steps S270 and S280 are similar to the processes of steps S50 and S60.

[0058] If the amplitude is greater than the amplitude threshold in step S240, the ECU 40 determines that the living body 100 is present in the vehicle (step S290) and ends the series of processes. If the kurtosis is greater than the kurtosis threshold in step S260, the process of step S290 is also executed and the series of processes ends. The process of step S290 is the same as the process of step S70. The other configurations are the same as those described in the preceding embodiment.

[0059] <Summary of the third embodiment> According to this embodiment, it is possible to obtain the same effect as the preceding embodiment. For example, even if a time lag of the order of ns occurs in multiple receptions, that is, sampling variations occur, it is possible to detect the presence or absence of the living body 100. Therefore, it is possible to improve the detection accuracy of the living body 100 in the vehicle.

[0060] The ECU 40 may first determine the presence or absence of the living body 100 based on the time fluctuation of the multiple received signals, that is, the amplitude, and if the living body 100 is not detected based on the amplitude, determine the presence or absence of the living body 100 based on the frequency characteristics of the multiple received signals. By using the amplitude as described above, not only the fluctuation due to breathing of the living body 100 but also the fluctuation due to body movement can be detected. Furthermore, even if the minute fluctuation due to breathing is buried in the fluctuation of the received signal due to sampling variation and the living body 100 cannot be detected based on the amplitude, the breathing can be detected by using the frequency characteristics, that is, the living body 100 can be detected. In other words, the detection accuracy of the living body 100 in the vehicle can be further improved.

[0061] <Modification> The ECU 40 may first detect the presence or absence of the living body 100 based on the amplitude, and when the living body 100 is detected based on the amplitude, detect the presence or absence of the living body 100 based on the frequency characteristics of the received signal multiple times. As shown in FIG. 19, the ECU 40 judges whether the amplitude is greater than the amplitude threshold (step S240), and calculates the frequency characteristics when the amplitude is greater than the amplitude threshold (step S250). The ECU 40 judges whether the kurtosis is greater than the kurtosis threshold (step S260), and when the kurtosis is greater than the kurtosis threshold, it determines that a living body is present (step S290). That is, when the amplitude>amplitude threshold and the kurtosis>kurtosis threshold, it determines that a living body is present. When the values ​​are equal to or less than the thresholds in steps S240 and S260, the loop process is executed until there are no more sampling points, and when there are no more sampling points, the loop process is terminated (step S270) and it is determined that there is no living body (step S280).

[0062] Increasing the number of sampling points increases the possibility of detecting the living body 100, but also increases the possibility of responding to disturbances such as pedestrians outside the vehicle. When using amplitude, for example, when the radar 30 is attached to the ceiling, the amount of minute breathing fluctuation at a position far from the radar 30, such as at the feet, may be equivalent to the amount of breathing fluctuation outside the vehicle. According to this embodiment, not only the amplitude but also the frequency characteristic is used. Since the presence or absence of the living body 100 is detected in two stages, erroneous detection can be suppressed.

[0063] (Fourth embodiment) This embodiment is a modification based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, an example of removing disturbances by using amplitude and frequency characteristics is shown. Instead of or in addition to this, disturbances may be removed by using relative speed.

[0064] Fig. 20 shows the process executed by the living body detection device according to this embodiment, that is, the living body detection method. Fig. 21 shows an example of the displacement of a moving object relative to a radar (e.g., a UWB radar). Fig. 22 shows the change in the relative speed.

[0065] For example, when the doors of the vehicle 10 are locked, the living body detection device 20 executes a living body detection process shown in Fig. 20. The processes of steps S310, S320, S330, and S340 are similar to the processes of steps S10, S20, S30, and S40 shown in Fig. 14.

[0066] If the amplitude is greater than the threshold value in step S340, the ECU 40 calculates the relative speed based on an arbitrary received waveform among the multiple received signals (received waveforms) (step S350). The ECU 40 determines whether the object is a moving object 110 outside the vehicle based on the relative speed (step S360).

[0067] By using the radar 30 as a Doppler sensor, the relative speed of the moving object 110 with respect to the radar 30 can be calculated. When calculating the relative speed by the Doppler principle, the time width used for measurement, that is, the reception time of the reflected wave, is lengthened. This results in a result that includes the component of the relative speed during that time width. As shown in FIG. 21, when the moving object 110 moves so as to cross the radar 30, if the time width is widened, the relative speed will change from moment to moment because a line-of-sight component is obtained. As a result, as shown in FIG. 22, the relative speed has various values, and it is possible to determine whether or not the moving object 110 is outside the vehicle using this as a feature. The moving object 110 outside the vehicle is, for example, a pedestrian outside the vehicle or an adjacent vehicle.

[0068] It is also possible to calculate the distance of the moving object 110 together with the relative speed, and determine whether or not the moving object 110 is outside the vehicle based on the distance and the relative speed. By adding the distance, it is possible to more reliably detect whether or not the moving object 110 is outside the vehicle.

[0069] If the amplitude is equal to or smaller than the threshold value in step S340, or if it is determined in step S360 that the object is a moving object 110 outside the vehicle, the ECU 40 executes the loop process until there are no more sampling points. When there are no more sampling points, the loop process ends (step S370) and it is determined that there is no living body (step S380). The processes of steps S370 and S80 are the same as those of steps S50 and S60.

[0070] If it is determined in step S360 that the object is not a moving object 110 outside the vehicle, the ECU 40 determines that a living body is present (step S390). That is, if the amplitude is greater than the threshold and the object is not a moving object 110 outside the vehicle, the ECU 40 determines that a living body is present. The process of step S390 is the same as the process of step S70. The other configurations are the same as those described in the preceding embodiment.

[0071] <Summary of the Fourth Embodiment> According to this embodiment, it is possible to obtain the same effect as the preceding embodiment. For example, even if a time lag of the order of ns occurs in multiple receptions, that is, sampling variations occur, it is possible to detect the presence or absence of the living body 100. Therefore, it is possible to improve the detection accuracy of the living body 100 in the vehicle.

[0072] When detecting the presence or absence of the living body 100 inside the vehicle, the ECU 40 may calculate the relative speed of the moving body 110 based on any received signal and determine whether the moving body 110 is outside the vehicle. By using the relative speed, it is possible to determine whether the living body 100 detected using the amplitude is a moving body 110 outside the vehicle. By using the relative speed, it is possible to remove disturbances such as pedestrians outside the vehicle and adjacent vehicles, and to suppress erroneous detection. In other words, it is possible to improve the accuracy of detecting the presence or absence of the living body 100 inside the vehicle.

[0073] Although an example of combining the detection of the living body 100 using the amplitude and the detection of the moving body 110 outside the vehicle using the relative speed has been shown, the present invention is not limited to this. The detection of the living body 100 using the frequency characteristic and the detection of the moving body 110 outside the vehicle using the relative speed may be combined. The detection of the living body 100 using the amplitude and frequency characteristic and the detection of the moving body 110 outside the vehicle using the relative speed may be combined.

[0074] Fifth embodiment This embodiment is a modification based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, the living body detection device includes only one radar disposed inside the vehicle. Instead of this, the living body detection device may include a radar disposed inside the vehicle and a radar disposed outside the vehicle.

[0075] Fig. 23 shows an example of radar arrangement in the living body detection device according to this embodiment. Fig. 24 shows the process executed by the living body detection device, that is, the living body detection method. Fig. 25 shows the received waveforms of one pulse of the in-vehicle radar and the external radar.

[0076] As illustrated in FIG. 23, the living body detection device 20 includes an in-vehicle radar 301 and an external radar 302 as radars 30. The in-vehicle radar 301 is a radar 30 arranged inside the vehicle, and the external radar 302 is a radar 30 arranged outside the vehicle. In this embodiment, as an example, the multiple radars 30 are also used as a smart entry system. The multiple radars 30 are, for example, UWB radars. The radar 30 includes one in-vehicle radar 301 and four external radars 302. The in-vehicle radar 301 is used, for example, for starting the engine. The external radars 302 are arranged near the four corners of the vehicle 10. The external radars 302 are used for unlocking and unlocking the door.

[0077] For example, when the doors of the vehicle 10 are locked, the living body detection device 20 executes the living body detection process shown in FIG. 24. The living body detection device 20 controls the operation of the radar 30 (301, 302) so as to execute the transmission / reception process for a predetermined period (step S410). The ECU 40 operates the external radar 302 in parallel with the internal radar 301. The ECU 40 controls, for example, the internal radar 301 and the external radar 302 so that the pulse transmission timing, the reflected wave reception time, and the transmission / reception interval are approximately the same. The processes of steps S410, S420, S430, and S440 are the same as the processes of steps S10, S20, S30, and S40 shown in FIG. 14. The ECU 40 executes steps S430 and S440 based on the reception signal of the internal radar 301. If the amplitude is greater than the threshold in step S440, the ECU 40 calculates the amount of fluctuation in the reception strength caused by the moving object 110 (step S450). The ECU 40 determines whether the object is a moving object 110 outside the vehicle based on the magnitude relationship of the amount of fluctuation (step S460).

[0078] As described above, the living body detection device 20 includes the in-vehicle radar 301 and the external radar 302. Disturbances from the moving object 110 outside the vehicle can be removed based on the difference between the reception strength of the in-vehicle radar 301 and the reception strength of the external radar 302. For example, when a moving object 110 such as a pedestrian or an adjacent vehicle crosses outside the vehicle, the fluctuation in the reception strength of the in-vehicle radar 301 is small and the fluctuation in the reception strength of the external radar 302 is large, as shown by the arrows in FIG. 25. Therefore, this difference can be used to determine whether or not the moving object is an external moving object 110. For example, when the amount of fluctuation of the external radar 302 is larger than the amount of fluctuation of the in-vehicle radar 301, the ECU 40 determines that the moving object is an external moving object 110.

[0079] If the amplitude is equal to or smaller than the threshold value in step S440, or if it is determined in step S460 that the object is a moving object 110 outside the vehicle, the ECU 40 executes the loop process until there are no more sampling points. When there are no more sampling points, the loop process ends (step S470) and it is determined that there is no living body (step S480). The processes of steps S470 and S480 are the same as those of steps S50 and S60.

[0080] If it is determined in step S460 that the object is not a moving object 110 outside the vehicle, the ECU 40 determines that a living body is present (step S490). That is, if the amplitude is greater than the threshold and the object is not a moving object 110 outside the vehicle, the ECU 40 determines that a living body is present. The process of step S490 is the same as the process of step S70. The other configurations are the same as those described in the preceding embodiment.

[0081] <Summary of the Fifth Embodiment> According to this embodiment, it is possible to obtain the same effect as the preceding embodiment. For example, even if a time lag of the order of ns occurs in multiple receptions, that is, sampling variations occur, it is possible to detect the presence or absence of the living body 100. Therefore, it is possible to improve the detection accuracy of the living body 100 in the vehicle.

[0082] The radar 30 may include an in-vehicle radar 301 and an external radar 302. The ECU 40 may detect the presence or absence of the living body 100 based on the received signal of the in-vehicle radar 301 and the received signal of the external radar 302. The external radar 302 is more susceptible to the influence of moving objects 110 outside the vehicle, such as pedestrians outside the vehicle and adjacent vehicles, than the in-vehicle radar 301. By using the received signal of the in-vehicle radar 301 and the received signal of the external radar 302, disturbances such as pedestrians outside the vehicle and adjacent vehicles can be removed, and false detections can be suppressed. In other words, the accuracy of detecting the presence or absence of the living body 100 inside the vehicle can be improved.

[0083] Although an example has been shown in which detection of a moving body 110 outside the vehicle using the reception signal of the in-vehicle radar 301 and the reception signal of the external radar 302 is combined with detection of a living body 100 using amplitude, the present invention is not limited to this. Detection of a moving body 110 outside the vehicle using the reception signal of the in-vehicle radar 301 and the reception signal of the external radar 302 may be combined with detection of a living body 100 using frequency characteristics. Detection of a moving body 110 outside the vehicle using the reception signal of the in-vehicle radar 301 and the reception signal of the external radar 302 may be combined with detection of a living body 100 using amplitude and frequency characteristics.

[0084] Sixth embodiment This embodiment is a modification based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, an example in which the input / output modules are replaced depending on the vehicle model and specifications is shown. Alternatively or additionally, the number of input / output modules may be increased or decreased.

[0085] Fig. 26 shows an example of mounting positions of a plurality of radars on a vehicle. Fig. 27 shows the process executed by the living body detection device according to this embodiment, that is, the living body detection method.

[0086] As illustrated in Fig. 26, the living body detection device 20 includes a plurality of radars 30 arranged inside the vehicle. The plurality of radars 30 are, for example, UWB radars. The plurality of radars 30 are arranged in the front-rear direction of the vehicle 10 at a predetermined interval. Each radar 30 is attached to the ceiling. In this embodiment, the vehicle 10 is a bus as an example. Three radars 30 are attached to the vehicle 10.

[0087] For example, when the doors of the vehicle 10 are locked, the living body detection device 20 executes the living body detection process shown in FIG. 27. The ECU 40 first starts loop process 1 (step S510). The living body detection device 20 executes the loop process for the multiple radars 30 in sequence. Next, the ECU 40 controls the operation of the radar 30 so as to execute the transmission and reception process for a predetermined period (step S520). The ECU 40 acquires a plurality of reception signals from the radar 30 during the predetermined period, and starts loop process 2 (step S530). Steps S520, S530, S540, S550, S560, S570, and S580 are the same as the processes of steps S10, S20, S30, S40, S50, S60, and S70 shown in FIG. 14. The loop process 2 (loop 2) corresponds to the loop process described in the preceding embodiment.

[0088] After executing the process of step S570 or the process of step S580 for one of the radars 30, the ECU 40 executes the living body detection process from step S520 onwards for the other radar 30. When the living body detection process is completed for all the radars 30, the ECU 40 ends the loop process (step S590) and ends the series of processes. The other configurations are the same as those described in the preceding embodiment.

[0089] <Summary of the Sixth Embodiment> According to this embodiment, it is possible to obtain the same effect as the preceding embodiment. For example, even if a time lag of the order of ns occurs in multiple receptions, that is, sampling variations occur, it is possible to detect the presence or absence of the living body 100. Therefore, it is possible to improve the detection accuracy of the living body 100 in the vehicle.

[0090] The living body detection device 20 may include a plurality of radars 30 arranged in the vehicle. The plurality of radars 30 may transmit and receive signals a plurality of times at different timings, and the ECU 40 may detect the presence or absence of the living body 100 based on the received signals in the plurality of transmissions and receptions of each radar 30. In the case of a vehicle 10 having a large size such as a bus, it is assumed that a plurality of radars 30 are installed in the vehicle to detect the presence or absence of the living body 100. In this case, if there is a direct wave that directly enters from one of the radars 30 into another of the radars 30, the reception strength increases as described above, and there is a risk that the fluctuation due to the living body 100 is buried in the fluctuation of the reception strength due to the sampling variation. In this embodiment, since the plurality of radars 30 transmit and receive signals a plurality of times at different timings, each radar 30 does not receive a direct wave from the other radars 30. Therefore, while detecting the presence or absence of the living body 100 in a wide vehicle, it is possible to suppress a decrease in the detection accuracy of the living body 100 due to the influence of the other radars 30. For example, it is possible to improve the accuracy of detecting an abandoned child.

[0091] The method of reducing or eliminating the influence of the direct wave from the other radar 30 is not limited to the method of shifting the transmission and reception timing exemplified in Fig. 27. For example, a method of removing the received direct wave based on a predetermined positional relationship of the antennas may be adopted.

[0092] The configuration described in this embodiment can be combined with any of the configurations described in the preceding embodiments.

[0093] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes the omission of parts and / or elements of the embodiments. The disclosure includes the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

[0094] The disclosure in the specification and drawings is not limited by the claims. The disclosure in the specification and drawings includes the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification and drawings without being bound by the claims.

[0095] When an element or layer is referred to as being "on," "coupled," "connected," or "bonded," it may be directly coupled, connected, or bonded to another element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly bonded" to another element or layer, there are no intervening elements or layers. Other words used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items. That is, a reference to A and / or B means at least one of A and B.

[0096] Spatially relative terms such as "inside," "outside," "back," "bottom," "low," "top," "top," and the like are utilized herein to facilitate the description of the relationship of one element or feature to another element or feature as depicted in the figures. Spatially relative terms may be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "directly below" other elements or features would be oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of top and bottom. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used in this specification would be interpreted accordingly.

[0097] The processor 41 may be a CPU, an MPU, a GPU, a DFP, or the like. CPU is an abbreviation for Central Processing Unit. MPU is an abbreviation for Micro-Processing Unit. GPU is an abbreviation for Graphics Processing Unit. DFP is an abbreviation for Data Flow Processor.

[0098] Some or all of the functions of the processor 41 may be realized by combining a plurality of types of arithmetic processing devices. Some or all of the functions of the processor 41 may be realized by using SoC, ASIC, FPGA, etc. SoC is an abbreviation for System on Chip. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array. Some or all of the functions of the processor 41 may be realized by using a hardware logic circuit.

[0099] The program may be stored in a computer-readable non-transitory tangible storage medium as instructions executed by a computer. The program may be stored in a storage medium such as an HDD, an SSD, or a flash memory. HDD is an abbreviation for Hard-disk Drive. SSD is an abbreviation for Solid State Drive.

[0100] In the above embodiment, an example of detecting the presence or absence of a living body using the intensity obtained from the IQ signal has been shown, but the present invention is not limited to this. For example, the presence or absence of a living body may be detected using the IQ signal itself, or the presence or absence of a living body may be detected using the phase obtained from the IQ signal. The phase corresponds to the output value of an arctangent whose input value is the ratio of the Q (Quadrature-Phase) component to the I (In-Phase) component of the received signal. The magnitude of the I component corresponds to the intensity of the in-phase component of the received signal. The magnitude of the Q component corresponds to the intensity of the quadrature component of the received signal. The I component is obtained by multiplying the received signal by a carrier wave output by a local oscillator. In addition, the Q component is obtained by multiplying the received signal by a signal whose phase is shifted by 90° from the output signal of the local oscillator. Furthermore, the presence or absence of a living body may be detected using only the I component of the IQ signal, or the presence or absence of a living body may be detected using only the Q component.

[0101] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple dependent claims. Some of the claims may be described in a multiple dependent form, referring to preceding claims in a subsequent claim as an alternative. Furthermore, some of the claims may be described in a multiple dependent form, referring to another multiple dependent form. The claims described in these multiple dependent forms define multiple technical ideas.

[0102] <Technical philosophy 1> At least one radar (30) mounted on a vehicle (10), transmitting a pulse wave of a predetermined frequency and receiving a reflected wave of the pulse wave; a detection unit (40) for detecting the presence or absence of a living body inside the vehicle based on a signal received by the radar; Equipped with The radar performs transmission and reception a plurality of times at predetermined intervals; a reception time of the reflected wave is longer than a time corresponding to a distance between the radar and a position at an end of the vehicle farthest from the radar, The detection unit detects the presence or absence of the living body based on a received signal from the multiple transmissions and receptions.

[0103] <Technical philosophy 2> The detection unit detects the presence or absence of the living body based on a time variation of the multiple received signals.

[0104] <Technical philosophy 3> The living body detection device according to Technical Idea 1 or 2, wherein the detection unit detects the presence or absence of the living body based on frequency characteristics of the multiple received signals.

[0105] <Technical philosophy 4> The detection unit is The living body detection device according to Technical Idea 2 detects the presence or absence of the living body based on the time variation, and then detects the presence or absence of the living body based on the frequency characteristics of the multiple received signals.

[0106] <Technical philosophy 5> The living body detection device according to any one of Technical Ideas 1 to 4, wherein the detection unit calculates a relative speed of a moving object based on any one of the received signals, and determines whether or not the moving object is present outside the vehicle.

[0107] <Technical philosophy 6> The radar includes an interior radar (301) disposed inside the vehicle and an exterior radar (302) disposed outside the vehicle, The living body detection device according to any one of Technical Ideas 1 to 4, wherein the detection unit detects the presence or absence of the living body based on a reception signal of the interior radar and a reception signal of the exterior radar.

[0108] <Technical philosophy 7> The radar system includes a plurality of the radars, The plurality of radars transmit and receive signals a plurality of times at different timings, The living body detection device according to any one of Technical Ideas 1 to 6, wherein the detection unit detects the presence or absence of the living body based on a received signal in the multiple transmissions and receptions of each radar.

[0109] <Technical philosophy 8> The biological detection device according to any one of Technical Concepts 1 to 7, wherein the radar is an UWB radar. [Explanation of symbols]

[0110] 10…Vehicle, 11…Ceiling, 20...Body detection device, 30…Radar, 301…In-vehicle radar, 302…External radar, 31…Antenna, 40…ECU, 41...processor, 42…Memory, 43…Storage, 100…Living organisms, 100s…body surface, 110...Mobile

Claims

1. At least one radar (30) mounted on a vehicle (10), transmitting a pulse wave of a predetermined frequency and receiving a reflected wave of the pulse wave; A detection unit (40) for detecting the presence or absence of a living body inside the vehicle based on a received signal from the radar; Equipped with The radar performs transmission and reception a plurality of times at predetermined intervals; a reception time of the reflected wave is longer than a time corresponding to a distance between the radar and a position at an end of the vehicle farthest from the radar, The detection unit detects the presence or absence of the living body based on a received signal from the multiple transmissions and receptions.

2. The living body detection device according to claim 1 , wherein the detection unit detects the presence or absence of the living body based on a time variation of the multiple received signals.

3. The living body detection device according to claim 1 , wherein the detection unit detects the presence or absence of the living body based on frequency characteristics of the multiple received signals.

4. The detection unit is The living body detection device according to claim 2 , further comprising: a detecting unit configured to detect the presence or absence of the living body based on the time variation, and then detect the presence or absence of the living body based on frequency characteristics of the multiple received signals.

5. 5. The living body detection device according to claim 1, wherein the detection unit calculates a relative speed of a moving object based on any one of the received signals, and determines whether or not the moving object is present outside the vehicle.

6. The radar includes an interior radar (301) arranged inside the vehicle and an exterior radar (302) arranged outside the vehicle, 5. The living body detection device according to claim 1, wherein the detection unit detects the presence or absence of the living body based on a signal received by the interior radar and a signal received by the exterior radar.

7. The vehicle includes a plurality of the radars arranged in a vehicle interior, The plurality of radars transmit and receive signals a plurality of times at different timings, 5. The living body detection device according to claim 1, wherein the detection unit detects the presence or absence of the living body based on a received signal in the multiple transmissions and receptions of each radar.

8. The living body detection device according to any one of claims 1 to 4, wherein the radar is an UWB radar.

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