JP2022043592A - Occupant detection device, and occupant detection system - Google Patents

Abstract

To provide an occupant detection device and the like that do not need computation processing of a frequency analysis and the like in a moving body, secure occupant detection accuracy even with a device configuration made simple, and can detect occupants in short time.SOLUTION: An occupant detection device includes: a comparison analysis unit that determines a reflection time determination value for determining whether an occupant is seated on a seat based on a reflection time until a reflection wave from a reflection body is received since a transmitted radio wave is transmitted, in which there is a case where the reflection body is the occupant to be seated on the seat, or a detected reflection body to be installed in the seat, and there is a case where the reflection body is provided in the seat, or adjacent to the seat; and a detection determination unit that, when the reflection time until the reflection wave from the reflection body is received since the transmitted radio wave is transmitted is smaller than the reflection time determination value, determines that the occupant is seated on the seat, and, when the reflection time until the reflection wave from the reflection body is received since the transmitted radio wave is transmitted is larger than the reflection time determination value, determines that the occupant is not seated on the seat.SELECTED DRAWING: Figure 4

Description

The present invention relates to an occupant detection device and an occupant detection system.

As a method of detecting an occupant of a moving object including a vehicle, a method of transmitting a radio wave as a transmission wave and receiving a radio wave reflected by an object as a reflected wave to generate a sensor signal has been conventionally proposed.

For example, the occupant state detection system of Patent Document 1 includes a radio wave sensor, a signal processing device, an absentee detection unit, and a notification unit. The radio wave sensor is attached above one of a plurality of seats, transmits radio waves as transmitted waves, receives radio waves reflected by an object as reflected waves, and generates a sensor signal. The signal processing device determines whether or not the object is a human from the movement of the object in the detection area based on the sensor signal, and executes the determination process of outputting the determination result. Therefore, sampling is required a plurality of times in order to detect changes due to minute movements of the occupant, and a sufficient detection time is required. The departure detection unit detects whether or not a person has left the front seat. When the absentee detection unit detects the occurrence of an absentee state, the notification unit outputs an alarm if the signal processing device determines that the object in the detection area is a person. The signal processing device detects whether or not a person is present in the detection area by detecting the presence or absence of a characteristic of human breathing based on the sensor signal.

Japanese Unexamined Patent Publication No. 2020-101415

However, in the above-mentioned occupant state detection system, it takes time to detect the occupant state because arithmetic processing such as frequency analysis is required. Further, compared to a system that does not require arithmetic processing such as frequency analysis, there is a concern that the above-mentioned occupant state detection system has a complicated configuration and an increase in cost.

The present invention has been made in view of the problems of the prior art. Further, an object of the present invention is to ensure occupant detection accuracy and detect occupants in a short time while simplifying the device configuration without the need for arithmetic processing such as frequency analysis in a moving body such as a vehicle. It is to provide a possible occupant detection device and occupant detection system.

An occupant detection device according to an aspect of the present invention, which is arranged on a moving body and detects whether or not a occupant is seated on the seat of the moving body by radio waves, and is initially set to the operation mode of the occupant detecting device. An operation mode and a detection operation mode are included, and when the occupant detection device operates in the detection operation mode, the occupant is determined by the reflection time from the time of transmission of the transmitted radio wave to the time when the reflected wave from the reflector is received. Is a comparative analysis unit that determines a reflection time determination value for determining whether or not is seated in a seat, and the reflector is a occupant seated in the seat or a test reflector installed in the seat. In some cases, the comparative analysis unit may be a reflector provided in or adjacent to the seat, and the reflection time from the time of transmission of the transmitted radio wave to the reception of the reflected wave from the reflector is the reflection. If it is smaller than the time determination value, it is determined that the occupant is seated in the seat, and the reflection time from the transmission of the transmitted radio wave to the reception of the reflected wave from the reflector is the reflection time. When it is larger than the determination value, it is preferable to include a detection determination unit for determining that the occupant is not seated in the seat.

When the occupant detection device operates in the initial operation mode, it is a directional control unit that determines transmission / reception directional information for determining the transmission / reception direction of radio waves, and is between the seat and the occupant detection device. The directional control unit further includes the directional control unit that determines the beam direction in which the reflected wave received from the reflector provided in or adjacent to the seat is received as transmission / reception directional information in a state where there is no radio obstacle in the propagation path of the radio wave. The comparative analysis unit transmits the radio wave transmitted to the reflector provided in or adjacent to the seat in a state where there is no radio wave obstacle in the propagation path of the radio wave between the seat and the occupant detection device according to the transmission / reception directional information. The reference reflection time indicating the time from the time of transmission to the reception of the reflected wave from the reflector is determined, and the person is seated in the seat between the reflector and the occupant detection device according to the transmission / reception directional information. The test reflection time, which indicates the time until the reflected wave of the radio wave transmitted to the occupant or the test reflector installed in the seat, is received, is determined from the time between the reference reflection time and the test reflection time. It is preferable to determine the reflection time determination value.

Further including the update operation mode, when the occupant detection device operates in the update operation mode, the directivity control unit has a radio wave obstacle in the propagation path of the radio wave between the seat and the occupant detection device. The beam direction in which the reflected wave from the reflector provided in or adjacent to the seat is received is determined as new transmission / reception directivity information, and the comparative analysis unit determines the new transmission / reception directivity information according to the new transmission / reception directivity information. The reference reflection time was remeasured, the test reflection time was remeasured according to the new transmission / reception directivity information, and the time between the remeasured reference reflection time and the test reflection time was calculated. It is preferable to update the reflection standard determination value.

The transmission / reception directivity information is information indicating the beam direction in which the amplitude of the reflected wave is the largest, or information indicating the beam direction in which the radio wave is directed to be transmitted to the central portion of the region where the reflected wave can be measured. Is preferable.

When the occupant detection device operates in the detection operation mode, the comparative analysis unit cannot determine the reflected wave, or the peak value of the amplitude of the reflected wave is smaller than a predetermined value. The beam direction is changed by the directional control unit, a region where the reflected wave can be measured is searched, and the shape of the region is seated by the occupant from the shape of the region where the reflected wave can be measured by the comparative analysis unit. It is preferable to include an abnormal value control unit that analyzes whether or not the shape is the same and controls the detection determination unit to determine whether or not the occupant is seated in the seat from the shape of the region.

The occupant detection system according to another aspect of the present invention includes a occupant detection device, the seat arranged on the moving body, and a directional antenna of the radio wave, and the occupant detection device is in front of the seat. Therefore, it is preferable that the reflector is provided inside the moving body having no radio wave obstacle in the propagation path of the radio wave between the seat and the occupant detection device, and the reflector is provided on the backrest portion of the seat.

According to the present invention, in a moving body such as a vehicle, arithmetic processing such as frequency analysis is not required, and it is possible to secure occupant detection accuracy and detect occupants in a short time while simplifying the device configuration. It becomes possible to provide an occupant detection device and an occupant detection system.

It is a schematic diagram which shows an example of the occupant detection system which concerns on this embodiment. It is a schematic diagram which shows an example of the seat of the vehicle which concerns on this embodiment. It is a measurement result which shows an example of the reflected wave received by the occupant detection device which concerns on this embodiment. It is a block diagram which shows an example of the structure of the occupant detection device which concerns on this embodiment. It is a flowchart which shows an example of the operation of the occupant detection device which concerns on this embodiment. It is a flowchart which shows an example of the operation of the occupant detection device which concerns on this embodiment. It is a flowchart which shows an example of the operation of the occupant detection device which concerns on this embodiment. It is a block diagram which shows the other example of the structure of the occupant detection device which concerns on this embodiment. It is a schematic diagram which shows the other example of the occupant detection system which concerns on this embodiment. It is a schematic diagram which shows an example of the structure related to the seat of the vehicle in the occupant detection system of FIG. 7 which concerns on this embodiment. It is a schematic diagram which shows an example of the principle of the Doppler effect which concerns on a comparative example.

Hereinafter, an example of the occupant detection device and the occupant detection system according to the present embodiment will be described in detail with reference to the drawings. The embodiments described below are comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, the order of steps, and the like shown in the following embodiments are examples, and are not intended to be limited to the present disclosure. Further, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept are described as arbitrary components. Furthermore, the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

The same functions and configurations are designated by the same or similar reference numerals, and the description thereof will be omitted as appropriate.

(Overview of occupant detection system)
The occupant detection system according to the present embodiment includes at least one radio wave transmitting unit, at least one radio wave reflecting unit, and at least one radio wave receiving unit. When the occupant is not seated on a seat such as a seat between the radio wave transmitting section and the radio wave reflecting section, the radio wave transmitted from the radio wave transmitting section is reflected by the radio wave reflecting section, and the reflected radio wave is reflected by the radio wave receiving section. Receive at. When an occupant sits on a seat such as a seat between the radio wave transmitting section and the radio wave reflecting section, the radio wave transmitted from the radio wave transmitting section is reflected by the occupant, and the reflected radio wave is received by the radio wave receiving section. do. Since the radio wave propagation path between the radio wave reflected by the radio wave reflecting unit and the radio wave reflected by the occupant is different, the time from the transmission of the radio wave to the reception by the radio wave receiving unit is different. The occupant detection system according to the present embodiment makes it possible to detect whether or not an occupant is seated by the difference in the time from the transmission of the radio wave to the reception of the radio wave. The radio wave transmitting unit and the radio wave receiving unit can also be configured as a radio wave transmitting / receiving unit.

(Example of occupant detection system)
A part of an example of the occupant detection system is shown as a schematic diagram in FIG. FIG. 1 is an example of a case where the present embodiment is applied to a passenger seat of a vehicle as a moving body. The occupant detection device 100 is arranged in front of the occupant J1 so that there is no obstacle of radio waves between the occupant detection device 100 and the occupant J1. As an example, as shown in FIG. 1, the occupant detection device 100 may be attached to the surface of the instrument panel IP of the vehicle. A magazine rack M1 is arranged on the back surface of the backrest portion SS1 of the seat S1 on which the occupant J1 sits, and the magazine rack M1 may function as a main radio wave reflector. Further, the occupant detection device 100 may be capable of functioning as a wireless communication terminal. The occupant detection device 100 can also function as a radar. The radio wave transmitted from the occupant detection device 100 may be an electromagnetic wave. It is also possible to apply this embodiment to a driver's seat and a rear seat (not shown) of a vehicle as a moving body.

In FIG. 1, when a radio wave is transmitted from the occupant detection device 100, when the occupant J1 is not seated, the main component of the radio wave is reflected by the magazine rack M1 and the reflected wave is received by the occupant detection device 100. Ru. In this case, the radio wave reciprocates a distance x1. Further, when the occupant J1 is seated, the radio wave is reflected by the surface of the occupant J1's body, and the reflected wave is received by the occupant detection device 100. In this case, the radio wave reciprocates a distance x2. Therefore, since the propagation distance of the radio wave differs between the case where the occupant J1 is seated and the case where the occupant J1 is not seated, the time from the transmission of the radio wave to the reception from the occupant detection device 100 is different. different. The occupant detection device 100 can determine whether or not the occupant J1 is seated by the different transmission / reception time differences. The magazine rack M1 is preferably made of resin, but the magazine rack M1 may be a radio wave reflector, or the magazine rack M1 may include a radio wave reflector. For example, a radio wave reflector sheet may be included inside the magazine rack M1. Further, an example of the radio wave reflector is metal.

Further, it may be preferable that the radio wave transmitted from the occupant detection device 100 has directivity in order to improve the accuracy for detecting the occupant J1. For example, it may be preferable that the radiation range of the radio wave transmitted from the occupant detection device 100 is the same as, about the same as, or less than or equal to the body width of the occupant J1. If the radiation range of the radio wave transmitted from the occupant detection device 100 is too wide, the occupant detection device 100 may not be able to receive the reflected wave from the occupant J1 with sufficient intensity when the occupant J1 is seated. This is because it may be necessary to prevent this. Further, if the radiation range of the radio wave transmitted from the occupant detection device 100 is too wide, the occupant detection device 100 receives the reflected wave from an object other than the surface of the body of the seat S1 and the occupant J1, and the S / N ratio decreases. It may be necessary to prevent this. Further, it may be preferable that the vertical direction of the radiation range of the radio wave transmitted from the occupant detection device 100 is the same as, about the same as, or equal to or less than the vertical length of the magazine rack M1.

FIG. 2 is a schematic view in which a magazine rack M1 is arranged on the back surface of the backrest portion SS1 of the seat S1, and the magazine rack M1 is provided with a magazine pocket MP1. Although the magazine pocket MP1 is made of resin, the reflection in the sheet S1 is particularly strong in the magazine pocket MP1.

(Determination of reflection time judgment value)
FIG. 3 is a measurement result showing the relationship between the propagation loss of the reflected wave measured by the occupant detection device 100 and the transmission / reception time interval in the situation of FIG. 1 to which the present embodiment is applied. The solid line is the measurement result of the reflected wave when the occupant J1 is not seated on the seat S1. Further, the broken line is the measurement result of the reflected wave when the occupant J1 is seated on the seat S1. The reflected wave from the magazine pocket MP1 at the position of x1 in FIG. 1 corresponds to tmax1 indicating the peak of the solid line in FIG. That is, it is shown from the experimental results that the reflected wave is more strongly reflected in the magazine pocket MP1 than in the sheet S1. Further, the reflected wave from the occupant J1 at the position of x2 in FIG. 1 corresponds to tmax2 showing the peak of the broken line in FIG. Therefore, it is also possible to determine whether or not the occupant J1 is seated on the seat S1 from the time difference between tmax1 and tmax2.

The peak of the reflected wave when the occupant J1 is not seated on the seat S1 may be an average value measured a plurality of times in advance at the time of manufacturing the vehicle by a known method. Further, at the time of servicing the vehicle, tmax1 may be measured a plurality of times again, and tmax1 may be updated by the average value measured a plurality of times by a known method. For example, when the radio wave environment inside the vehicle may change due to changes over time due to the use of the vehicle, it is expected that the accuracy of detecting the occupant J1 will be improved by updating tmax1 during maintenance of the vehicle. There is.

Further, since the occupant J1 may be a human being of various body shapes such as men and women of all ages, when the initial measurement of tmax2 is performed, it is preferable that the occupant assumed as the occupant J1 is a subject having the minimum body thickness. By determining tmax2 in advance in this way, it becomes possible to detect the occupant J1 having a fuselage thickness equal to or greater than the minimum value of the fuselage thickness assumed to be detected. As an example, it is also possible to use the torso thickness of a minor whose torso thickness is smaller than that of an adult as the minimum value of the torso thickness. Further, when measuring tmax2, it may be possible to use a test object having a radio wave reflectance similar to that of a human torso and having the same thickness as the minimum value of the torso thickness instead of the subject. Further, at the time of measuring tmax2, in the occupant J1 of FIG. 1, the subject sits deeply on the seat S1 so that x2 becomes the largest, and the tmax2 is measured in a state where the subject is closest to the magazine pocket MP1 which is the main reflector. Is preferably executed. It is preferable to determine the maximum value of tmax2 by such a measurement. According to the maximum value of tmax2, when the occupant J1 sits shallowly on the seat S1 or when the occupant J1 changes his / her posture on the seat S1, the value of x2 becomes small, so that the detection accuracy of the occupant J1 May be possible to improve.

Using the tmax1 and tmax2 measured as described above, it is also possible to determine the reflection time determination value TH1 shown in FIG. 3 as follows. As an example, | tmax1 + tmax2 | / 2 can be determined as the reflection time determination value TH1. As described above, tmax1 may be the average value of the peak values measured a plurality of times, and tmax2 may also be the average value of the peak values measured a plurality of times. Further, the reflection time determination value may be finely adjusted so that the presence or absence of an occupant can be accurately detected from a plurality of different occupants. Further, the time corresponding to the minimum value of | (amplitude of the reflected signal when there is no occupant)-(amplitude of the reflected signal when there is an occupant) | between tmax1 and tmax2 may be determined as the reflection time determination value TH1. It is possible. The reflection time determination value TH1 determined as described above can be stored in a predetermined area of the storage unit 160.

An example of the case where the occupant J1 changes his / her posture on the seat S1 includes the case where the occupant J1 turns his / her upper body toward the door window side and the case where the occupant J1 takes a forward leaning posture. As described above, it may be possible to detect the occupant J1 having a thickness equal to or greater than the minimum value of the set fuselage thickness regardless of the posture of the occupant J1. This is because the transmission / reception time of the reflected wave by the occupant J1 having the body thickness equal to or larger than the set minimum value of the body thickness is theoretically smaller than the reflection time determination value TH1. As described above, it is preferable that the measurements of tmax1 and tmax2 are performed and set at the time of vehicle development and updated at the time of manufacturing and maintenance. Alternatively, the measurements of tmax1 and tmax2 are preferably performed, set and updated during maintenance of the vehicle.

(Configuration example of occupant detection device)
FIG. 4 is a block diagram showing an example of the configuration of the occupant detection device 100. As shown in FIG. 4, the occupant detection device 100 includes a transmission signal processing unit 110 and a transmission unit 120. It includes a receiving unit 130, a receiving signal processing unit 140, a control unit 150, a storage unit 160, and an external I / F unit 170. Hereinafter, only the portion related to the feature in the present embodiment will be described, but the occupant detection device 100 may include other functional blocks not directly related to the feature in the present embodiment. The occupant detection device 100 may or may not include the transmission array antenna unit SAA and the reception array antenna unit RAA. Further, the transmission array antenna unit SAA and the reception array antenna unit RAA may be arranged outside the occupant detection device 100 or inside the occupant detection device 100.

Further, although not shown in FIG. 4, the transmission array antenna unit SAA and the reception array antenna unit RAA of the occupant detection device 100 may be used as one array antenna unit AA, and may include a transmission / reception switching unit. In this case, the transmission unit 120 and the reception unit 130 are configured as one transmission / reception unit, and the transmission / reception switching unit (not shown) switches the connection between the transmission signal processing unit 110 and the reception signal processing unit 140 and the transmission / reception unit (not shown). ..

The transmission signal processing unit 110 has a function of generating a transmission signal transmitted via the transmission unit 120 and the transmission array antenna unit SAA. For example, the transmission signal processing unit 110 may include a variable frequency transmitter. Further, the transmission signal may be a sine wave waveform, a pulse waveform, or an arbitrary modulated waveform generated by a single frequency. Further, it is preferable that the main frequency component of the transmission signal does not include the frequency component used for communication in the mobile body, between the mobile bodies, and between the mobile body and the electronic device outside the mobile body.

The transmission unit 120 has a function of outputting the transmission signal generated by the transmission signal processing unit 110 to the transmission array antenna unit SAA. Further, the transmission unit 120 may include an amplifier (not shown) for amplifying the transmission signal. As shown in FIG. 4, when the transmission array antenna unit SAA is connected to the transmission unit 120, the transmission unit 120 has a phase (not shown) in order to control the directivity of the radio wave radiated from the transmission array antenna unit SAA. It is possible to include a vessel. The phase detector can be arranged as many as the number of antenna elements so as to give different phases to each antenna element of the transmission array antenna unit SAA. The phase information of each phase unit is generated by the directivity control unit 152 and input to the transmission unit 120. Further, the transmission signal is transmitted from the transmission unit 120 to each antenna element of the transmission array antenna unit SAA, and at the same time, the transmission trigger signal is transmitted from the transmission unit 120 to the timing unit 151, and the timing unit 151 starts timing. Further, in FIG. 4, three antenna elements, the antenna element SAA1, the antenna element SAA2, and the antenna element SAA3, are shown as the antenna elements of the transmission array antenna unit SAA, but the number of antenna elements may be arbitrary.

The reception unit 130 has a function of outputting the reception signal received by the reception array antenna unit RAA to the reception signal processing unit 140. The received signal received by the receiving array antenna unit RAA is preferably a reflected wave of the transmitted signal. Further, the receiving unit 130 may include an amplifier (not shown) for amplifying the received signal. Further, in order to match the phase of the received signal received by each antenna element of the receiving array antenna unit RAA, the receiving unit 130 can include a phase detector (not shown). The phase detector can be arranged as many as the number of antenna elements. The phase information of each phase unit is generated by the directivity control unit 152 and input to the reception unit 130. Further, the received signal of each antenna element that has passed through a phase device (not shown) is added by an adder (not shown) to form the received signal shown in FIG. 3 and the like. Further, when the reception signal is received by the reception unit 130, the reception trigger signal is transmitted to the time measurement unit 151, and the time measurement unit 151 can measure the transmission / reception time.

The reception signal processing unit 140 has a function of receiving processing of a reception signal transmitted via the reception array antenna unit RAA and the reception unit 130. For example, the received signal processing unit 140 includes an A / D converter (Analog-to-digital converter) (not shown), and can convert the received signal into a digital signal. Further, when the received signal is modulated, the received signal processing unit 140 can also demodulate the modulated received signal. Further, the received signal processing unit 140 may be able to smooth the received signal. When the smoothing process is executed, either the received signal as an analog signal or the digitized received signal, or both the received signal as an analog signal and the digitized received signal are sent. On the other hand, it is possible to execute smoothing processing.

When the received signal is digitized, the digitized received signal can be stored in the storage unit 160. For example, as shown in FIG. 3, the amplitude information and the time information for reproducing the received signal waveform reflected by the magazine pocket MP1 of the sheet S1 shown by the solid line are stored in the storage unit 160 as a pair of information. Is possible. Similarly, the amplitude information and the time information for reproducing the received signal waveform reflected by the occupant J1 shown by the broken line in FIG. 3 can be stored in the storage unit 160 as a pair of information. The time information indicates the time interval between adjacent digital signals. Further, instead of the time information, the time information indicated by the time measuring unit 151 may be used. In this case, the time information at which the radio wave is transmitted is also stored in the storage unit 160, and the difference from the time information of each received signal can be used as the reflection time.

The received signal processing unit 140 may be able to output a non-digitized received signal to the comparative analysis unit 153, which will be described later. For example, the comparative analysis unit 153 may include a peak hold circuit. The received signal as a non-digitized analog signal is input from the received signal processing unit 140 to the peak hold circuit of the comparative analysis unit 153, and tmax1 and tmax2 as shown in FIG. 4 can be detected. In some cases. In this case, the occupant detection device 100 does not need to store the digitized data in the storage unit 160 and extract the peak value from the stored data, so that high-speed processing may be possible. The time detection method in this case will be described in detail in the comparative analysis unit 153 described later.

As shown in FIG. 4, the control unit 150 can include a timekeeping unit 151, a directivity control unit 152, a comparative analysis unit 153, an abnormal value control unit 154, a detection determination unit 155, and a mode determination control unit 156. Is.

The timekeeping unit 151 has a function of ensuring synchronization between the transmission signal and the reception signal and measuring the time from the transmission time of the transmission signal to the reception time of the reflection signal from the reflector such as the magazine pocket MP1 or the occupant J1. For example, the transmission time of the transmission signal is set to time 0, and the change in the amplitude value of the reception signal received by the reception unit 130 from time 0 can be associated with the time information. For example, it is possible to add time information to the output digital signal from the sampling start time of the received signal input to the A / D converter, the sampling time interval, and the order of the output digital signals. For example, by setting the sampling start time to time 0, it becomes possible to specify the time information at the peak of the received signal as shown in FIG.

The directivity control unit 152 has a function of controlling the directivity which is the beam direction of the transmission array antenna unit SAA and the reception array antenna unit RAA. The directivity can be controlled by a phase detector (not shown) included in the transmitting unit 120 and the receiving unit 130. The beam direction is adjusted so as to face the direction in which the reflector of the radio wave is arranged, and the adjusted phase information to be input to each phase device can be stored in the storage unit 160.

For example, when the occupant detection device 100 operates in the initial operation mode or the update operation mode, the directivity control unit 152 scans the beam direction up, down, left, and right, and determines the beam direction in which the reflected wave is maximum in the update beam direction. It is stored in the storage unit 160 as information. Alternatively, the directivity control unit 152 may store the central direction of the beam direction in which the reflected wave is obtained in the storage unit 160 as updated beam direction information.

As an example, the comparative analysis unit 153 may have a function of sequentially comparing the amplitude values of the reflected signals, which are the received signals, stored in the storage unit 160. The reflected signal to be compared is a series of reflected signals having different reception times for one transmitted signal. For example, the amplitude values of the reflected signals reflected by the magazine pocket MP1 of the sheet S1 shown by the solid line in FIG. 3 are sequentially compared, and the peak value is extracted. An example of the peak value is tmax1. Similarly, the amplitude values of the reflected signals reflected by the occupant J1 shown by the broken line in FIG. 3 are sequentially compared, and the peak value is extracted. An example of the peak value is tmax2. Further, since the time information is associated with the amplitude value, the comparison analysis unit 153 can extract the time information for the peak value from the storage unit 160.

When the comparative analysis unit 153 includes a peak hold circuit (not shown), it is possible to hold the peak value of the analog waveform from the analog waveform of the reflected signal which is the received signal. Further, the hold timing of the peak value can be detected by the level change of the output of the comparator circuit included in the peak hold circuit. For example, when the held peak value is input to one end of the comparator circuit, the analog waveform of the reflected signal is input to the other end of the comparator circuit, and the reflected signal whose amplitude value is lower than the peak value is input, the comparator circuit The output level of is configured to be inverted. When the signal whose output level of the comparator circuit is inverted is referred to as an inverted signal, the inverted signal is input to the time measuring unit 151, so that the hold timing of the peak value can be detected. As described above, in this case, the occupant detection device 100 does not need to store the digitized data in the storage unit 160 and extract the peak value from the stored data, so that high-speed processing is possible. May be.

Further, the comparative analysis unit 153 executes different operations depending on the operation mode determined by the mode determination control unit 156. For example, when the operation mode determined by the mode determination control unit 156 is the initial operation mode, the storage unit 160 stores information on the reflected signal at the time of development or manufacture of the moving body. The reflected signal information may be measured by the occupant detection device 100 and stored in the storage unit 160, or a predetermined value may be stored in the storage unit 160 via the external I / F unit 170 or the like. May be good.

For example, the reflected signal information when the occupant detection device 100 actually measures and stores it in the storage unit 160 includes the amplitude information of the reflected signal and the reflected signal after the transmission signal is transmitted, as described above. May include time information. In this case, the reflected signal included in the storage unit 160 is reflected by the reflected signal reflected by the magazine pocket MP1 of the sheet S1 shown by the solid line in FIG. 3 and by the occupant J1 shown by the broken line in FIG. Reflected signals are included. When the comparative analysis unit 153 is in the initial operation mode, the comparative analysis unit 153 extracts the occupant-less reflection time corresponding to the peak value of the reflected signal reflected by the magazine pocket MP1 of the sheet S1 stored in the storage unit 160. do. For example, the occupant-free reflex time may be tmax1. When the comparative analysis unit 153 is in the initial operation mode, the comparative analysis unit 153 extracts the occupant reflection time corresponding to the peak value of the reflected signal reflected by the occupant J1 stored in the storage unit 160. For example, the occupant reflection time may be tmax2. Then, as an example, the comparative analysis unit 153 can determine | (reflex time without occupant) + (reflection time with occupant) | / 2 as the reflection time determination value. The unoccupied reflection time may be the average value of the peak values measured a plurality of times, and the occupant-less reflection time may be the average value of the peak values measured a plurality of times. Further, the reflection time determination value may be finely adjusted so that the presence or absence of an occupant can be accurately detected from a plurality of different occupants. In addition, the time corresponding to the minimum value of | (amplitude of the reflected signal with no occupant)-(amplitude of the reflected signal with occupant) | between (reflection time without occupant) and (reflection time with occupant) | is reflected. It can also be determined as a time determination value. The reflection time determination value determined as described above can be stored in a predetermined area of the storage unit 160 by the comparative analysis unit 153.

Further, for example, the information of the reflected signal to be stored in the storage unit 160 assumed at the time of design or development may include a reflection time without a occupant, a reflection time with a occupant, and a reflection time determination value. In this case, information values such as the reflection time determination value may be set in advance and stored in the storage unit 160. Further, in this case, the mounting position of the occupant detection device 100 and the seat position of the seat or the like may be determined.

When the detection operation mode is determined by the mode determination control unit 156, the comparative analysis unit 153 analyzes whether or not the occupant is seated on the seat S1 based on the above-mentioned reflection time determination value. The peak value reception time corresponding to the peak value of the reflected signal is analyzed. As described above, the peak value reception time can be extracted from the reflected signal information extracted from the storage unit 160 by the comparative analysis unit 153. Further, the peak value reception time can be determined as described above by the peak hold circuit included in the comparative analysis unit 153.

When the update operation mode is determined by the mode determination control unit 156, the occupant detection device 100 transmits radio waves in a new beam direction determined by the directivity control unit 152 while the occupant is not seated on the seat. Send. Then, the comparative analysis unit 153 measures the reception time of the reflected wave from the magazine pocket MP1 of the sheet, and sets the reflection time of the reflected wave between the occupant detection device 100 and the magazine pocket MP1 as a new tmax1 in the storage unit 160. Remember.

Next, the occupant detection device 100 transmits radio waves in a new beam direction determined by the directivity control unit 152 while the occupant is seated on the seat. Then, the comparative analysis unit 153 measures the reflection time to the surface of the occupant seated on the seat, and stores the reflection time as a new tmax2 in the storage unit 160.

The comparative analysis unit 153 determines a new reflection time determination value from the new tmax1 and the new tmax2 stored in the storage unit 160, and stores the determined new reflection time determination value in the storage unit 160.

The outlier control unit 154 has a function of executing outlier processing as follows when it is determined that the reflection time is not a value in an appropriate range. When it is determined that the reflection time is not within an appropriate range, the outlier control unit 154 first retransmits the radio wave from the transmission unit 120, and the comparative analysis unit 153 measures the reflection time again. May be tried. For example, if the measured value of the reflection time is larger than tmax1 and the measured value of the reflection time is between tmax1 and the reflection time determination value, the occupant detection device 100 tries to measure the reflection time again. However, if it is determined that the measured value of the reflection time is not in an appropriate range even after re-measuring a predetermined number of times, the following processing may be executed. It is possible to set an arbitrary value for the predetermined number of times in the occupant detection system 1000.

For example, if there is a seat position sensor (not shown) and an angle sensor (not shown) of the backrest portion of the seat, the position of the magazine pocket MP1 may be estimated from the information and the reflection time determination value may be estimated. Even if the reflected wave cannot be detected or the peak value of the reflected wave is very small, if there is a seat position sensor or an angle sensor for the backrest, the position of the magazine pocket MP1 is estimated and the reflection time is determined. The value may be estimated. For example, when the position of the seat is slid backward, or when the backrest portion of the seat is tilted, the above processing may be required. In these cases, the beam direction is adjusted to the estimated magazine pocket MP1 placement direction, and the reflection time is measured.

Further, for example, a seat position sensor (not shown) and a seat angle sensor (not shown) may not be arranged. In this case, the directivity control unit 152 scans the beam direction, and the comparative analysis unit 153 determines whether the reflector is the magazine pocket MP1 or the occupant from the shape of the scanning range in which the reflected wave is measured. It may be possible to estimate. When the reflected wave is estimated to be the reflected wave from the magazine pocket MP1, it may be possible to optimize the beam direction of the reflected wave and estimate the reflection time determination value. A detailed description in this case will be described in FIG. 5 (c).

The detection determination unit 155 has a function of determining whether or not an occupant is seated on the seat of the moving body. When the reflection time analyzed by the comparative analysis unit 153 is within an appropriate range and the reflection time is smaller than the reflection time determination value, the detection / determination unit 155 seats the moving body on the occupant. Is determined to be seated. Further, when the reflection time analyzed by the comparative analysis unit 153 is in an appropriate range and the reflection time is larger than the reflection time determination value, the detection determination unit 155 is a moving sheet. It is determined that the occupant is not seated.

If the detection determination unit 155 determines that the measured value of the reflection time is not in the appropriate range, the measurement of the reflection time is simply repeated and continuously, and the measured value of the reflection time is not in the appropriate range. If determined, it may be configured to perform the above actions.

The mode determination control unit 156 has a function of determining the operation mode of the occupant detection device 100. Examples of the operation mode include operation modes such as an initial operation mode, a detection operation mode, and an update operation mode, but the operation mode is not limited to these operation modes. For example, the operation mode may include a mode that enables the occupant detection device 100 to operate as a wireless transmission / reception terminal.

The operation mode information indicating the operation mode can be input from an external electronic device connected to the external I / F unit 170. The external electronic device may be an electronic device including a CPU (Central Processing Unit). As an example, an arbitrary input device may be connected to an external electronic device, and the information input from the input device may be configured to identify any operation mode information. Further, a user interface may be arranged in the mode determination control unit 156 so that the operation mode information can be identified by the information input via the user interface. In any case, the operation mode information can be input by any known method.

When the occupant detection device 100 is set to the initial operation mode by the mode determination control unit 156, the reflection time determination value indicating whether or not the occupant is seated is stored via the external I / F unit 170. It can be stored in a predetermined area of the unit 160. Further, the reflection time determination value indicating whether or not the occupant is seated via the user interface included in the mode determination control unit 156 is predetermined by the storage unit 160 via the external I / F unit 170. It can be stored in the area. Further, when the occupant detection device 100 is set to the initial operation mode, occupant presence / absence information indicating the presence / absence of an occupant as a subject is input, and the reflection time when the occupant is not seated and the occupant are seated. In some cases, the reflection time may be measured by the occupant detection device 100. In this case, the occupant detection device 100 can determine the reflection time determination value indicating whether or not the occupant is seated by the method described above. How to store the reflection time determination value in the storage unit 160 is determined by information input by an external electronic device (not shown) or a device such as a user interface included in the mode determination control unit 156. Is possible. That is, when the reflection time determination value is a value determined by the design, the reflection time determination value determined by the design is stored in the storage unit without actually measuring the reflection time on the moving body on which the occupant detection device 100 is mounted. It may be stored in 160. Further, the reflection time is measured when the occupant is seated and when the occupant is not seated in the moving body on which the occupant detection device 100 is mounted, and the reflection time determination value is determined by the comparative analysis unit 153 and stored in the storage unit 160. It may be stored in. It is preferable that the operation mode of the occupant detection device 100 is set to the initial operation mode at the time of development or manufacture of the moving body.

When the operation mode of the occupant detection device 100 is set to the detection operation mode by the mode determination control unit 156, the occupant detection device 100 transmits a radio wave, and the transmitted radio wave is the reflected wave reflected by the reflector. Whether or not the occupant is seated is determined based on the reflection time. Since the method for determining whether or not the occupant is seated has been described above, the description will be omitted in order to avoid duplication.

When the mode determination control unit 156 sets the occupant detection device 100 to the update operation mode, the radio wave environment due to changes in the moving body and the arrangement in the moving body, the arrangement of the arrangement, the attachment or detachment of the arrangement, and the like. Assuming a change, the reflection time judgment value is updated. For example, occupant presence / absence information indicating the presence / absence of an occupant as a subject is input to the occupant detection device 100, and the occupant detection device 100 determines the reflection time when the occupant is not seated and the reflection time when the occupant is seated. May be measured. In this case, the occupant detection device 100 can determine the reflection time determination value indicating whether or not the occupant is seated by the method described above. Then, the occupant detection device 100 rewrites the old reflection time determination value to the determined new reflection time determination value. It is preferable that the operation mode of the occupant detection device 100 is set to the update operation mode at the time of inspection or inspection of the moving body. When the moving body is a vehicle, it is preferable that the operation mode of the occupant detection device 100 is set to the update operation mode at the time of periodic inspection or vehicle inspection of the vehicle.

In some cases, the mode determination control unit 156 can set the operation mode of the occupant detection device 100 to a mixed mode of the detection operation mode and the wireless transmission / reception terminal mode. In this case, the operation of the detection operation mode described above and the operation of the wireless transmission / reception terminal mode described later can be executed in a time-division manner.

The external I / F unit 170 has an interface function with an external electronic device connected to the occupant detection device 100. It can be connected to an external electronic device by wire or wirelessly. Further, the external electronic device may be a node connected to a network in the mobile body. The external electronic device may include a vehicle control device as an in-vehicle device, a vehicle sensing device, a vehicle peripheral information acquisition device, and an electronic device such as an entertainment device. The vehicle control device may include a navigation device and an automatic driving control device. It is also possible to connect to an external I / F unit of an external electronic device to send and receive information. Further, an ECU (Electronic Control Unit) may be configured by a device connected to the external I / F unit 170.

The occupant detection system according to the present embodiment according to the above description can be mounted on a moving body such as a vehicle.

(Operation example of occupant detection device 100)
An operation example of the occupant detection device 100 according to the present embodiment will be described with reference to FIGS. 5A to 5C.

The processing procedure of FIGS. 5A to 5C of the occupant detection device 100 is executed by the CPU (Central Processing Unit) of the occupant detection device 100. The CPU (for example, the control unit 150 in FIG. 4) is executed by the CPU according to a program stored in a ROM (Read Only Memory) (for example, a part of the storage unit 160 in FIG. 4).

It should be noted that some or all of the following processing procedures can be executed by hardware such as DSP and ASIC. However, in this embodiment, a case where the CPU executes according to the ROM program will be described.

In step S501, the mode determination control unit 156 acquires the operation mode information indicating the mode in which the occupant detection device 100 should operate via the external I / F unit 170 or the user interface included in the mode determination control unit 156. do. Next, the occupant detection device 100 proceeds to step S502.

In step S502, the mode determination control unit 156 determines whether or not the operation mode to be operated by the occupant detection device 100 is the detection operation mode from the operation mode information acquired in step S501. When the operation mode of the occupant detection device 100 is the detection operation mode (step S502: YES), the occupant detection device 100 proceeds to step S503. If the operation mode of the occupant detection device 100 is not the detection operation mode (step S502: NO), the occupant detection device 100 proceeds to step S511.

In step S503, the transmission unit 120 sets the beam direction according to the directivity information input from the directivity control unit 152, and transmits radio waves from the transmission array antenna unit SAA. Timekeeping is started in the timekeeping unit 151 from the time when the radio wave is transmitted. Next, the occupant detection device 100 proceeds to step S504.

In step S504, the reception unit 130 converts the information received in each reception element of the reception array antenna unit RAA into one reception signal and outputs it to the reception signal processing unit 140. As will be described later, information that exceeds a predetermined level and can be recognized as a reflected wave may not be acquired, but the receiving unit 130 executes the above processing based on the information received by each receiving element. do. Next, the occupant detection device 100 proceeds to step S505.

In step S505, the comparative analysis unit 153 calculates the time from the peak value of the received signal received and processed by the received signal processing unit 140 from the transmission of the radio wave to the reception of the reflected wave by the reflector. When the radio wave environment changes due to a change in the arrangement of the magazine pocket MP1, there is no peak value of the reflected wave, the peak value of the reflected wave is abnormally small, or there is no reflected wave and the peak. In some cases, it may not be possible to calculate the value. In these cases, the next process is determined in step S506. The occupant detection device 100 proceeds to step S506.

In step S506, the comparative analysis unit 153 determines whether or not the reflection time from the peak value of the received signal to the reception of the reflected wave from the transmission of the radio wave is an abnormal value. The abnormal value includes the above-mentioned case where there is no peak value of the reflected wave, the case where the peak value of the reflected wave is abnormally small, or the case where there is no reflected wave and the peak value cannot be calculated. Is also included. Further, when the reflection time calculated by the peak value of the received signal is larger than tmax1 and when it is a value between the reflection time determination value and tmax1, it is determined that the reflection time is an abnormal value. To. When the reflection time from the transmission of the radio wave to the reception of the reflected wave is an abnormal value (step S506: YES), the occupant detection device 100 proceeds to step S526. If the time from the transmission of the radio wave to the reception of the reflected wave is not an abnormal value (step S506: NO), the occupant detection device 100 proceeds to step S507.

In step S507, the detection determination unit 155 extracts the reflection time determination value stored in the storage unit 160. Next, the occupant detection device 100 proceeds to step S508.

In step S508, the detection determination unit 155 compares the calculated reflection time with the reflection time determination value extracted from the storage unit 160. When the calculated reflection time is smaller than the reflection time determination value (step S508: YES), the occupant detection device 100 proceeds to step S509. When the calculated reflection time is larger than the reflection time determination value (step S508: NO), the occupant detection device 100 proceeds to step S510.

In step S509, the detection determination unit 155 determines that the occupant is seated on the seat of the moving body, and transmits the occupant seating information to the external electronic device via the external I / F unit 170. Next, the occupant detection device 100 returns to step S501.

In step S510, the detection determination unit 155 determines that the occupant is not seated on the seat of the moving body, and transmits the occupant unseat information to the external electronic device via the external I / F unit 170. Next, the occupant detection device 100 returns to step S501.

In step S511, the mode determination control unit 156 determines whether or not the operation mode to be operated by the occupant detection device 100 is the initial operation mode from the operation mode information acquired in step S501. When the operation mode set in the occupant detection device 100 is the initial operation mode (step S511: YES), the occupant detection device 100 proceeds to step S512. If the operation mode set in the occupant detection device 100 is not the initial operation mode (step S511: NO), the occupant detection device 100 proceeds to step S517.

In step S512, the directivity control unit 152 scans the beam direction up, down, left, and right, and stores the beam direction in which the reflected wave is maximized in the storage unit 160 as initial beam direction information. Alternatively, the central direction of the beam direction in which the reflected wave is obtained may be stored in the storage unit 160 as initial beam direction information. Further, when the occupant detection device 100 is attached to the position determined by the design, the pre-designed initial beam direction information may be stored in the storage unit 160. Further, the occupant detection device 100 calculates the distance from the reflected wave in the beam direction corresponding to the initial beam direction information to the reflector, and stores the calculated distance to the reflector as the initial reflector distance information in the storage unit 160. Remember. Next, the occupant detection device 100 proceeds to step S513.

In step S513, the occupant detection device 100 outputs the initial beam direction information and the initial reflector distance information acquired in step S512. The initial beam direction information and the initial reflector distance information may be output via the external I / F unit 170 or may be output via the user interface of the mode determination control unit 156. Then, when the initial beam direction information and the appropriate range information indicating that the initial reflector distance information is in the appropriate range are input (step S513: YES), the occupant detection device 100 proceeds to step S514. If the appropriate range information is not detected (step S513: NO), the occupant detection device 100 returns to step S512.

In step S514, the occupant detection device 100 transmits radio waves in the beam direction corresponding to the initial beam direction information determined in step S512 in a state where the occupant is not seated on the seat. Then, the occupant detection device 100 measures the reception time of the reflected wave from the magazine pocket MP1 of the seat, and stores the reflection time of the reflected wave between the occupant detection device 100 and the magazine pocket MP1 as tmax1 in the storage unit 160. .. tmax1 may be a single measurement or an average of a plurality of measurements measured by various known methods. Next, the occupant detection device 100 proceeds to step S515.

In step S515, the occupant detection device 100 transmits radio waves in the beam direction corresponding to the initial beam direction information determined in step S512 while the occupant is seated on the seat. Then, the occupant detection device 100 measures the reflection time to the surface of the occupant seated on the seat, and stores the reflection time as tmax2 in the storage unit 160. tmax2 may be a single measurement or an average of a plurality of measurements measured by various known methods. Since the method for measuring tmax2 has been described above, detailed description thereof will be omitted. Next, the occupant detection device 100 proceeds to step S516.

In step S516, the occupant detection device 100 determines a reflection time determination value from tmax1 and tmax2 stored in the storage unit 160, and stores the determined reflection time determination value in the storage unit 160. Since the method for measuring the reflection time determination value has been described above, detailed description thereof will be omitted. Next, the occupant detection device 100 returns to step S501.

In step S517, the mode determination control unit 156 determines whether or not the operation mode to be operated by the occupant detection device 100 is the update operation mode from the operation mode information acquired in step S501. When the operation mode set in the occupant detection device 100 is the update operation mode (step S517: YES), the occupant detection device 100 proceeds to step S518. If the operation mode set in the occupant detection device 100 is not the update operation mode (step S517: NO), the occupant detection device 100 proceeds to step S525.

In step S518, the directivity control unit 152 scans the beam direction up, down, left, and right, and stores the beam direction in which the reflected wave is maximized in the storage unit 160 as updated beam direction information. Alternatively, the central direction of the beam direction in which the reflected wave is obtained may be stored in the storage unit 160 as updated beam direction information. Further, the occupant detection device 100 calculates the distance from the reflected wave in the beam direction corresponding to the updated beam direction information to the reflector, and stores the calculated distance to the reflector as the updated reflector distance information in the storage unit 160. Remember. Next, the occupant detection device 100 proceeds to step S519.

In step S519, the occupant detection device 100 outputs the updated beam direction information and the updated reflector distance information acquired in step S518. The updated beam direction information and the updated reflector distance information may be output via the external I / F unit 170, or may be output via the user interface of the mode determination control unit 156. Then, when the update beam direction information and the appropriate range information indicating that the update reflector distance information is in the appropriate range are input (step S519: YES), the occupant detection device 100 proceeds to step S520. If the appropriate range information is not detected (step S519: NO), the occupant detection device 100 returns to step S518.

In step S520, tmax1 update information indicating whether or not tmax1 should be updated is input via the user interface of the external I / F unit 170 or the mode determination control unit 156. If tmax1 should be updated (step S520: YES), the occupant detection device 100 proceeds to step S521. If tmax1 should not be updated (step S520: NO), the occupant detection device 100 proceeds to step S522.

In step S521, the occupant detection device 100 transmits radio waves in the beam direction corresponding to the updated beam direction information determined in step S518 in a state where the occupant is not seated on the seat. Then, the occupant detection device 100 measures the reflection time up to the magazine pocket MP1 of the seat, and updates and stores the reflection time between the occupant detection device 100 and the magazine pocket MP1 as a new tmax1 in the storage unit 160. The new tmax1 may be a single measurement or an average of a plurality of measurements measured by various known methods. Next, the occupant detection device 100 proceeds to step S522.

In step S522, tmax2 update information indicating whether or not tmax2 should be updated is input via the user interface of the external I / F unit 170 or the mode determination control unit 156. If tmax2 should be updated (step S522: YES), the occupant detection device 100 proceeds to step S523. If tmax2 should not be updated (step S522: NO), the occupant detection device 100 proceeds to step S524.

In step S523, the occupant detection device 100 transmits radio waves in the beam direction corresponding to the updated beam direction information determined in step S518 while the occupant is seated on the seat. Then, the occupant detection device 100 measures the reflection time to the surface of the occupant seated on the seat, and updates the reflection time between the occupant detection device 100 and the surface of the occupant to the storage unit 160 as a new tmax2. And remember. The new tmax2 may be a single measurement or an average of a plurality of measurements measured by various known methods. Since the method for measuring tmax2 has been described above, detailed description thereof will be omitted. Next, the occupant detection device 100 proceeds to step S524.

In step S524, the occupant detection device 100 determines a reflection time determination value from tmax1 and tmax2 stored in the storage unit 160, and stores the determined reflection time determination value in the storage unit 160. Even if tmax1 and tmax2 are initial values. It may also be an updated value. Since the method for measuring the reflection time determination value has been described above, detailed description thereof will be omitted. Next, the occupant detection device 100 returns to step S501.

In step S525, the mode determination control unit 156 determines the operation mode in which the occupant detection device 100 should operate from the operation mode information acquired in step S501, and the occupant detection device 100 operates according to the determined mode. For example, the operation mode information may be a mixed mode in which a detection mode and a wireless transmission / reception terminal mode are mixed. In this case, the occupant detection device 100 can be configured to function as a transmission / reception terminal when a transmission request or a reception request occurs, and to execute the operations of steps S503 to S510 in other cases. Is. Alternatively, it may be configured to function as a transmission / reception terminal when a transmission request or a reception request occurs when the operations of steps S503 to S510 are being executed, and to execute the next step from an intermediate step. It is possible. When the operation mode information is the wireless transmission / reception terminal mode, the occupant detection device 100 can also function as a transmission / reception terminal included in the mobile network until new operation mode information is input.

In step S526, when the reflection time is an abnormal value, the occupant detection device 100 determines whether or not the radio wave has been retransmitted a predetermined number of times. When the occupant detection device 100 retransmits the radio wave a predetermined number of times (step S526: YES), the occupant detection device 100 proceeds to step S527. If the occupant detection device 100 does not retransmit the radio wave a predetermined number of times (step S526: NO), the occupant detection device 100 returns to step S503. The default number of times can be set to any number of times in the occupant detection system 1000. For example, in order to improve the occupant detection speed of the occupant detection device 100, the occupant detection system 1000 can set the default number of retransmissions to 0.

In step S527, the occupant detection device 100 determines whether or not a seat-related sensor such as a seat position sensor (not shown) and an angle sensor of the backrest portion of the seat is arranged in the occupant detection system 1000. When the seat-related sensor is arranged (step S527: YES), the occupant detection device 100 proceeds to step S528. When the seat-related sensor is not arranged (step S527: NO), the occupant detection device 100 proceeds to step S531.

In step S528, the occupant detection device 100 acquires seat position information from a seat position sensor (not shown), acquires angle sensor information of the backrest portion from an angle sensor of the backrest portion (not shown), and estimates the position of the magazine pocket MP1. Further, the occupant detection device 100 estimates the beam direction information of the radio wave to be transmitted from the estimated position of the magazine pocket MP1, and overwrites the estimated beam direction information in the storage area of the beam direction information of the storage unit 160. do. Next, the occupant detection device 100 proceeds to step S529.

In step S529, the occupant detection device 100 estimates the reflection time from the position of the magazine pocket MP1 estimated from the seat position information and the angle sensor information of the backrest portion acquired in step S528. The occupant detection device 100 stores the estimated reflection time as tmax1 in the storage unit 160. Next, the occupant detection device 100 proceeds to step S530.

In step S530, the occupant detection device 100 estimates the reflection time determination value from the difference time between the tmax1 estimated in step S529 and the initial tmax1 and tmax2 stored in the storage unit 160. Since the calculation method of the reflection time determination value has been described above, detailed description thereof will be omitted. The comparative analysis unit 153 can also use the value obtained by adding the difference time between the initial tmax1 and tmax2 to the tmax1 estimated in step S529 as a new reflection time determination value. Next, the occupant detection device 100 returns to step S503.

In step S531, the occupant detection device 100 scans the beam direction of the radio wave to be transmitted up, down, left, and right in the directivity control unit 152, and detects the beam direction in which the reflected wave can be received. Next, the occupant detection device 100 proceeds to step S532.

In step S532, the occupant detection device 100 calculates the solid angle of the reflected wave from the beam direction in which the reflected wave can be received, and estimates the surface shape of the reflector from the solid angle. Then, the occupant detection device 100 determines whether the reflector is the magazine pocket MP1 or the occupant from the estimated surface shape of the reflector. When the reflector is an occupant, a long surface shape in the vertical direction of the sheet is estimated, and when the reflector is a magazine pocket MP1, a square surface shape is estimated. If it is presumed that the reflector is the magazine pocket MP1 (step S532: YES), the process proceeds to step S533. If the reflector is presumed to be an occupant (step S532: NO), the process proceeds to step S509.

In step S533, the directivity control unit 152 stores in the storage unit 160 the beam direction in which the amplitude of the reflected wave received in step S531 becomes the maximum value as beam direction information. Alternatively, the central direction of the beam direction in which the reflected wave is obtained may be stored in the storage unit 160 as initial beam direction information. Further, the occupant detection device 100 measures the reflection time with the reflector from the reflected wave in the beam direction corresponding to the beam direction information, and stores the measured reflection time as tmax1 in the storage unit 160. Next, the occupant detection device 100 proceeds to step S534.

In step S534, the occupant detection device 100 estimates the reflection time determination value from the difference time between the tmax1 measured in step S533 and the initial tmax1 and tmax2 stored in the storage unit 160 and the new beam direction. .. Since the method for measuring the reflection time determination value has been described above, detailed description thereof will be omitted. The comparative analysis unit 153 uses the value obtained by adding the value obtained by correcting the difference time between the initial tmax1 and tmax2 in the new beam direction to the tmax1 measured in step S533 as a new reflection time determination value. It is also possible. Next, the occupant detection device 100 returns to step S503.

According to the occupant detection device 100 having the above configuration, in a moving body such as a vehicle, arithmetic processing such as frequency analysis is not required, and while the device configuration is simplified, the occupant detection accuracy is ensured and the occupant can be occupy in a short time. It becomes possible to provide an occupant detection device capable of detecting.

(Modification 1)
In the above description of the embodiment, the case where the array antenna is used for transmitting and receiving the radio wave of the occupant detection device 100 has been described, but the antenna used for the occupant detection device 100 is not limited to the array antenna. Any antenna can be used as long as the antenna used for the occupant detection device 100 is a directional antenna. For example, as shown in FIG. 6, a transmitting antenna SAT and a receiving antenna RAT that can mechanically change the beam direction of the antenna can also be used for the occupant detection device 100.

The beam directions of the transmitting antenna SAT and the receiving antenna RAT can be controlled by the transmitting unit 120 and the receiving unit 130 based on the directivity information generated by the directivity control unit 152.

Further, although not shown in FIG. 6, there is a case where the transmitting antenna SAT and the receiving antenna RAT of the occupant detection device 100 are used as one antenna and include a transmission / reception switching unit. In this case, the transmission unit 120 and the reception unit 130 are configured as one transmission / reception unit, and the transmission / reception switching unit (not shown) switches the connection between the transmission signal processing unit 110 and the reception signal processing unit 140 and the transmission / reception unit (not shown). ..

(Modification 2)
In the description of the above embodiment, whether or not the occupant is seated on the seat by the occupant detection device 100 installed in the automobile is described as an example. However, the embodiment is not limited to the inside of the automobile, and the occupant is seated in a moving body on which the occupant is boarded, such as an internal space of a moving body such as a bus, a train, an airplane, a spaceship, a ship, or a submersible. It can be applied to all purposes of detecting the presence or absence of.

(Modification 3)
In the above description of the embodiment, since the presence or absence of seating of the occupant J1 is determined by the reflection time from the magazine pocket MP1, it is necessary for the occupant detection device 100 to receive the reflected wave of sufficient strength from the magazine pocket MP1. There is.

Therefore, when a reflected wave having sufficient strength cannot be obtained from the magazine pocket MP1, a reflector such as a film sheet having a high radio wave reflectance can be attached to the inside or the outside of the magazine pocket MP1. It is also possible to insert a reflector between the front and back surfaces of the magazine pocket MP1. Further, even when the sheet S1 does not have a strong reflector such as the magazine pocket MP1, it is possible to attach a reflector such as a film sheet having a high radio wave reflectance to the area where the magazine pocket MP1 is expected to be provided. .. The surface shape of the reflector is preferably a shape that can be recognized as the surface shape of the occupant J1 in the seated state.

(Modification example 4)
In the above description of the embodiment, the case where the occupant detection device 100 is attached to the instrument panel has been described, but the position where the occupant detection device 100 is attached is not limited to the instrument panel. For example, the occupant detection device 100 can be attached to a windshield, a rear-view mirror, or a roof. When the occupant detection device 100 is attached to the roof, it may be attached in front of the occupant or above the occupant.

FIG. 7A shows a schematic view when the occupant detection device 100 is attached to the roof C1 above the occupant J1. The occupant detection device 100 attached to the roof C1 transmits radio waves downward, and stores the reflection time when the occupant J1 is absent as tmax1 in the storage unit 160. The radio wave transmitted from the occupant detection device 100 can be reflected by a reflector FR1 such as a metal sheet arranged under the sheet S1. The reflector FR1 is not limited to the metal sheet, and any object can be used as the reflector FR1 as long as it is an object made of a material that reflects radio waves. Further, if the floor of the moving body can function as a reflector instead of the reflector FR1, the reflector FR1 may not be used. Further, even when the reflector is formed by the metal frame of the sheet S1 or the metal parts attached to the metal frame, the reflector FR1 may not be used.

As shown in FIG. 7A, when the reflector FR1 is arranged and the occupant J1 is not seated, the radio wave reciprocating the distance x1 from the occupant detection device 100 to the reflector FR1. The time measured by is stored in the storage unit 160 as tmax1. Further, when the occupant J1 is seated, the radio wave is reflected by the head and thigh of the occupant J1, and the reflection time becomes a value smaller than tmax1. It is also possible to determine the reflection time determination value on the assumption that tmax1 rarely fluctuates when the reflector FR1 or the floor of the moving object functions as a reflector. For example, when the height of the sheet S1 can be adjusted, the reflection time from the lowest height position of the sheet S1 is calculated to calculate tmax2, which is stored in the storage unit 160. Alternatively, when the height of the sheet S1 cannot be adjusted, the reflection time from the height position of the sheet S1 is calculated, calculated as tmax2, and stored in the storage unit 160. The comparative analysis unit 153 calculates the reflection time determination value from the above-mentioned tmax1 and tmax2 by the method described in the embodiment, and stores it in the storage unit 160. When the main reflected wave from the occupant J1 is the reflected wave from the thigh of the occupant J1, and the occupant J1 is a minor or the like and the thigh is thin, the arrival time of the reflected wave is incorrect. May occur and the accuracy may decrease. Therefore, the above-mentioned method may be used for processing. The occupant detection device 100 can be operated as follows using the reflection time determination value calculated in this way. That is, when the occupant detection device 100 is in the detection operation mode, if the reflection time is smaller than the reflection time determination value, it is determined that the occupant J1 is seated, and if the reflection time is larger than the reflection time determination value. Can be determined that the occupant J1 is not seated.

FIG. 7B is a diagram schematically showing how the reflector FR1 is arranged directly under the sheet S1. A detailed description will be omitted.

FIG. 8A is a schematic view showing an example of the beam direction determined by the directivity control unit 152 when the occupant detection device 100 is attached to the roof C1 or the like above the occupant J1. If the beam direction is determined at the central portion of the reflector FR1 as in SD1, it is assumed that the intensity of the reflected wave also increases. θ1 / 2 indicates the full width at half maximum.

FIG. 8A is a schematic diagram showing an example of the beam direction determined by the directivity control unit 152 when the occupant detection device 100 is attached to the instrument panel IP or the like in front of the occupant J1. If the beam direction is determined in the central portion of the magazine pocket MP1 as in SD2, it is assumed that the intensity of the reflected wave also increases. θ2 / 2 indicates the full width at half maximum.

(Comparative Example 1)
When performing occupant detection in a vehicle by radar technology, there is a method of detecting the Doppler effect caused by the reflected wave of the radio wave on the human body surface due to the occupant's breathing and / or heartbeat. 9 (a) and 9 (b) show schematic diagrams illustrating a method of detecting the Doppler effect. In FIG. 9A, when the human body surface of the occupant J2 is displaced at the velocity v, the reflected wave of the radio wave having the frequency fc transmitted from the antenna ANT changes to fc + fd. Since the frequency fc of the transmitted radio wave is a known value, it is possible to analyze and detect the frequency fd from the fc + fd of the received reflected wave. Since the velocity v on the surface of the human body is calculated from these frequencies fc and fd, it is possible to determine whether or not the displacement velocity is due to the occupant's respiration and / or heartbeat.

However, according to the method of Comparative Example 1, since frequency analysis is required, it is assumed that the configuration of the apparatus is complicated and expensive.

(Comparative Example 2)
As a configuration that does not use frequency analysis, a part of the energy of the transmitted radio wave and the reflected wave reflected from the reflector are mixed to generate a standing wave, and the magnitude of the amplitude of the generated standing wave There is a method for determining whether or not the human body is seated from the fluctuation.

Although the above method does not require frequency analysis, it is necessary to determine the seating of the occupant in consideration of the fact that the amplitude of the reflected wave fluctuates depending on the posture and direction of the occupant, which complicates the determination algorithm. May be. In addition, when the above method is adopted to determine the seating of the occupants in the front seats of the vehicle, if there are occupants in the rear seats, the reflected waves from the occupants in the rear seats exist, so that the front seats and the rear seats It may be difficult to identify the occupants. Therefore, when the above method is adopted, there may be a problem in the occupant detection accuracy.

(Comparative Example 3)
In addition, as a configuration that does not use frequency analysis and does not use standing waves, there is a method to calculate the amount of movement of the reflector over time and determine whether or not the reflector is an occupant based on the amount of movement. exist.

However, in the above method, since a plurality of samplings are required to detect minute movements of the occupant, it is expected that it will take time to detect. In the future, in technologies such as automatic driving control, it is preferable to detect the presence or absence of seating of an occupant in real time, so it is desirable that the time required for detection is short.

In other words, connected cars are required to have occupant detection technology in order to utilize big data services, but the device configuration for occupant detection has been simplified, the cost of the device has been reduced, the occupant detection time has been short, and responsiveness has been achieved. Highly accurate technology is required. However, the above-mentioned conventional comparison technique has a problem that the above-mentioned future requirements cannot be satisfied.

However, according to the configuration according to the present embodiment, in a moving body such as a vehicle, arithmetic processing such as frequency analysis is not required, and while simplifying the device configuration, the occupant detection accuracy is ensured and the occupant can be occupy in a short time. It becomes possible to provide an occupant detection device or the like capable of detecting.

The features of the occupant detection device 100 and the occupant detection system 1000 of the present embodiment will be described below.

The occupant detection device 100, which is arranged on the moving body and detects whether or not the occupant is seated on the seat of the moving body by radio waves, according to the first aspect of the present invention, includes an initial operation mode, a detection operation mode, and an update. It is preferable that each operation mode of the operation mode is included. When the occupant detection device 100 operates in the detection operation mode, whether or not the occupant is seated in the seat is determined by the reflection time from the transmission of the transmitted radio wave to the reception of the reflected wave from the reflector. It is preferable that a comparative analysis unit 153 for determining the reflection time determination value to be determined is included. The reflector may be a occupant sitting in the seat or a reflector installed in the seat, or a reflector provided in or adjacent to the seat. When the reflection time from the transmission of the transmitted radio wave to the reception of the reflected wave from the reflector is smaller than the reflection time determination value, the detection determination unit 155 for determining that the occupant is seated in the seat is used. It is preferable to include it. Further, in the detection determination unit 155, when the reflection time from the transmission of the transmitted radio wave to the reception of the reflected wave from the reflector is larger than the reflection time determination value, the occupant is not seated in the seat. It is preferable to determine that.

According to the above configuration, in a moving body such as a vehicle, arithmetic processing such as frequency analysis is not required, and it is possible to secure occupant detection accuracy and detect occupants in a short time while simplifying the device configuration. It becomes possible to provide an occupant detection device.

When the occupant detection device 100 according to the second aspect of the present invention operates in the initial operation mode, it is preferable to include a directivity control unit 152 for determining transmission / reception directivity information for determining the transmission / reception direction of radio waves. .. The directivity control unit 152 transmits and receives the beam direction in which the reflected wave from the reflector provided in or adjacent to the seat is received in a state where there is no radio interference in the radio wave propagation path between the seat and the occupant detection device. It is preferable to determine it as sexual information. The comparative analysis unit 153 uses the transmission / reception directivity information to transmit the radio wave transmitted to the reflector provided in the seat or adjacent to the reflector in a state where there is no radio interference in the propagation path between the seat and the occupant detection device. It is preferable to determine a reference reflection time indicating the time until reception of the reflected wave from. Further, the comparative analysis unit 153 receives the reflected wave of the radio wave transmitted between the reflector and the occupant detection device according to the transmission / reception directivity information to the occupant seated in the seat or the test reflector installed in the seat. It is preferable to determine the test reflection time, which indicates the time of. Further, it is preferable that the comparative analysis unit 153 determines the reflection reference determination value from the time between the reference reflection time and the test reflection time.

According to the above configuration, in a moving body such as a vehicle, the beam direction in which the reflected wave from the reflector of the reflector related to the occupant or the seat can be received is appropriately determined, so that the occupant detection accuracy is ensured and the occupant detection accuracy is secured in a short time. It is also possible to detect the occupants. Further, since the reflection reference determination value is determined from the time between the reference reflection time and the test reflection time, arithmetic processing such as frequency analysis is not required, and the device configuration can be simplified.

When the occupant detection device 100 according to the third aspect of the present invention operates in the update operation mode, it is preferable to execute the following processing. That is, the directivity control unit 152 determines the beam direction in which the reflected wave from the reflector provided in or adjacent to the seat is received in a state where there is no radio interference in the radio wave propagation path between the seat and the occupant detection device. It is preferable to determine it as new transmission / reception directional information. The comparative analysis unit 153 remeasures the reference reflection time based on the new transmission / reception directivity information, remeasures the test reflection time based on the new transmission / reception directivity information, and remeasures the reference reflection time and the test reflection. It is preferable to update the time between the times as a new reflection reference determination value.

According to the above configuration, when there is a change over time in a moving object such as a vehicle, it is possible to determine and update a new reflection reference determination value by the update operation mode, so that the occupant detection accuracy can be improved. It is also possible to maintain and secure. In addition, even if the position of the reflector related to the seat changes, it is possible to appropriately determine the new beam direction, so it is possible to ensure occupant detection accuracy even with a simple device configuration. It will be possible.

The transmission / reception directivity information of the occupant detection device 100 according to the fourth aspect of the present invention is information indicating the beam direction in which the amplitude of the reflected wave is the largest, or the radio wave is transmitted to the central portion of the region where the reflected wave can be measured. It is preferable that the information indicates the direction of the beam to be directed.

According to the above configuration, in a moving body such as a vehicle, it is possible to easily determine the beam direction for transmitting and receiving radio waves in an appropriate direction for measuring the reflected wave. Therefore, it is possible to provide an occupant detection device capable of ensuring occupant detection accuracy and detecting an occupant in a short time while simplifying the device configuration.

When the occupant detection device 100 according to the fifth aspect of the present invention operates in the detection operation mode, the reflected wave cannot be determined, or the peak value of the amplitude of the reflected wave is smaller than a predetermined value. It is preferable that the outlier control unit 154 executes the following processing. That is, the directivity control unit 152 changes the beam direction, searches for a region where the reflected wave can be measured, and the shape of the region is changed from the shape of the region where the reflected wave can be measured by the comparative analysis unit 153, and the occupant sits down. It is preferable to control so as to analyze whether or not the shape has a shape. Then, it is preferable to have the detection determination unit 155 control the shape of the region so as to determine whether or not the occupant is seated in the seat.

According to the above configuration, even if an abnormal value occurs in the reflected wave due to a change in the position of the reflector related to the seat in a moving body such as a vehicle, the beam direction is scanned and the reflected wave is scanned. From the shape of the measurable area, it is possible to configure the configuration so that the occupant can be detected. Therefore, even if the radio wave environment related to the reflected wave changes, the occupant detection device can automatically and appropriately continue the occupant detection.

The occupant detection system 1000 according to the sixth aspect of the present invention includes the occupant detection device 100 according to any one of the first to fifth aspects, a seat arranged in a mobile body, and a directional antenna for radio waves. Is preferable. Further, the occupant detection device 100 is arranged in front of the seat and inside a moving body having no radio interference in the radio wave propagation path between the seat and the occupant detection device, and the reflector is placed on the backrest portion of the seat. It is preferable to be provided.

According to the above configuration, in a moving body such as a vehicle, it is not necessary to perform arithmetic processing such as frequency analysis on all seats, and while simplifying the device configuration, the occupant detection accuracy is ensured and the occupant can be occupied in a short time. It becomes possible to provide an occupant detection device capable of detecting. Further, since the reflected wave of the seat and the space in front of the seat is used, interference with other seats can be suppressed and the occupant detection accuracy can be improved.

In the occupant detection system 1000 according to the seventh aspect of the present invention, the reflector provided on the backrest portion of the seat is preferably a magazine rack that reflects radio waves or a reflective sheet provided on the magazine rack.

According to the above configuration, in a moving body such as a vehicle, a new configuration related to a seat is not required or an expensive configuration is not required, so that the occupant detection accuracy is ensured while simplifying the device configuration. Will be possible.

The occupant detection system 1000 according to the eighth aspect of the present invention includes the occupant detection device 100 according to any one of the first to fifth aspects, a seat arranged in a mobile body, and a directional antenna for radio waves. Is preferable. Further, the occupant detection device 100 is arranged above the seat and inside a moving body having no radio interference in the radio wave propagation path between the seat and the occupant detection device, and the reflector adjacent to the seat is It is preferably placed below the seat.

According to the above configuration, in a moving body such as a vehicle, it is not necessary to perform arithmetic processing such as frequency analysis on all seats, and while simplifying the device configuration, the occupant detection accuracy is ensured and the occupant can be occupied in a short time. It becomes possible to provide an occupant detection device capable of detecting. Further, since the reflected wave of the seat and the space above the seat is used, interference with other seats can be suppressed and the occupant detection accuracy can be improved.

In the occupant detection system 1000 according to the ninth aspect of the present invention, the reflector adjacent to the seat reflects radio waves, constitutes a moving body, is a floor member provided directly under the seat, or reflects radio waves. It is preferable that the reflective sheet is provided directly under the seat.

According to the above configuration, in a moving body such as a vehicle, a new configuration related to a seat is not required or an expensive configuration is not required, so that the occupant detection accuracy is ensured while simplifying the device configuration. Will be possible.

In the occupant detection system 1000 according to the tenth aspect of the present invention, it is preferable that the moving body is a vehicle and the occupant detection device 100 is installed for each seat of the vehicle.

According to the above configuration, in the vehicle, arithmetic processing such as frequency analysis is not required for each seat, and it is possible to secure the occupant detection accuracy and detect the occupant in a short time while simplifying the device configuration. It becomes possible to provide an occupant detection device. Further, since the configuration is such that radio wave interference between seats can be suppressed, it is possible to secure occupant detection accuracy even if calculation is easy.

The block configuration diagram of FIG. 4 used in the description of the above-described embodiment shows a block of functional units. These functional blocks are realized by any combination of at least one of hardware and software. Further, the method for realizing each functional block is not particularly limited. For example, each functional block may be realized using one physically or logically coupled device, or two or more physically or logically separated devices may be directly or indirectly connected. , These may be realized by using a plurality of devices. The functional block may be realized by combining software with one device or a plurality of devices.

When the occupant detection device 100 is composed of a plurality of hardware elements, each functional block is realized by any hardware element or a combination of the hardware elements. Hardware elements include processors, memory, storage, communication devices, input devices, output devices, buses, and the like.

Further, in this case, each function of the occupant detection device 100 is realized by loading predetermined software or a program on hardware such as a processor and a memory. Specifically, each function is realized by loading a predetermined software on the hardware so that the processor performs an operation and controls reading and writing of data in the memory and the storage.

Although the embodiments have been described in detail with reference to the drawings, the present invention is not limited to the contents described in the above embodiments. In addition, the components described above include those that can be easily assumed by those skilled in the art and those that are substantially the same. Further, the configurations described above can be combined as appropriate. In addition, various omissions, substitutions or changes of the configuration can be made without departing from the gist of the present invention.

100 Crew detection device 110 Transmission signal processing unit 120 Transmission unit 130 Reception unit 140 Reception signal processing unit 150 Control unit 151 Timekeeping unit 152 Directivity control unit 153 Comparison analysis unit 154 Abnormal value control unit 155 Detection judgment unit 156 Mode judgment control unit 160 Storage unit 170 External I / F unit 1000 Crew detection system

Claims (6)

It is an occupant detection device that is arranged on a moving body and detects whether or not an occupant is seated on the seat of the moving body by radio waves. The operation modes of the occupant detection device include an initial operation mode and a detection operation mode. Included,
When the occupant detection device operates in the detection operation mode,
In the comparative analysis unit that determines the reflection time determination value for determining whether or not the occupant is seated in the seat based on the reflection time from the transmission of the transmitted radio wave to the reception of the reflected wave from the reflector. Therefore, the reflector may be a occupant seated in the seat or a test reflector installed in the seat, or may be a reflector provided in or adjacent to the seat, and the comparative analysis unit.
If the reflection time from the time of transmission of the transmitted radio wave to the reception of the reflected wave from the reflector is smaller than the reflection time determination value, it is determined that the occupant is seated in the seat and transmission is performed. If the reflection time from the time of transmission of the transmitted radio wave to the reception of the reflected wave from the reflector is larger than the reflection time determination value, the detection determination unit for determining that the occupant is not seated in the seat. Crew detection device including. When the occupant detection device operates in the initial operation mode,
A directivity control unit that determines transmission / reception directivity information for determining the transmission / reception direction of radio waves, and the seat is in a state where there is no radio interference in the radio wave propagation path between the seat and the occupant detection device. Further includes the directivity control unit for determining the beam direction in which the reflected wave from the reflector provided or adjacent to the receiver is received as the transmission / reception directivity information.
The comparative analysis unit transmitted to the reflector provided in or adjacent to the seat in a state where there is no radio obstacle in the propagation path of the radio wave between the seat and the occupant detection device according to the transmission / reception directional information. A reference reflection time indicating the time from the transmission of the radio wave to the reception of the reflected wave from the reflector is determined, and the seat is seated between the reflector and the occupant detection device according to the transmission / reception directional information. The test reflection time indicating the time until the reflected wave of the radio wave transmitted to the occupant or the test reflector installed in the seat is received is determined, and the time between the reference reflection time and the test reflection time is determined. The occupant detection device according to claim 1, wherein the reflection time determination value is determined from the above. Including update operation mode
When the occupant detection device operates in the update operation mode,
The directivity control unit has a beam direction in which reflected waves from a reflector provided on or adjacent to the seat are received in a state where there is no radio interference in the radio wave propagation path between the seat and the occupant detection device. Is determined as new transmission / reception directional information,
The comparative analysis unit remeasures the reference reflection time according to the new transmission / reception directivity information, remeasures the test reflection time according to the new transmission / reception directivity information, and remeasures the measurement. The occupant detection device according to claim 2, wherein the time between the reference reflection time and the test reflection time is updated as a new reflection reference determination value. The transmission / reception directivity information is information indicating the beam direction in which the amplitude of the reflected wave is the largest, or information indicating the beam direction in which the radio wave is directed to be transmitted to the central portion of the region where the reflected wave can be measured. The occupant detection device according to claim 2 or 3. When the occupant detection device operates in the detection operation mode,
If the reflected wave cannot be determined by the comparative analysis unit, or if the peak value of the amplitude of the reflected wave is smaller than a predetermined value, the directional control unit changes the beam direction, and the reflected wave is generated. A measurable region is searched, and whether or not the shape of the region is a shape in which an occupant is seated is analyzed from the shape of the region where the reflected wave can be measured by the comparative analysis unit, and the detection determination is made. The occupant detection device according to any one of claims 2 to 4, further comprising an outlier control unit that controls the occupant to determine whether or not the occupant is seated in the seat based on the shape of the region. The occupant detection device according to any one of claims 1 to 5.
The seats placed on the moving body and
Including the directional antenna of the radio wave
The occupant detection device is arranged in front of the seat and inside the moving body having no radio interference in the radio wave propagation path between the seat and the occupant detection device.
The reflector is an occupant detection system provided on the backrest portion of the seat.

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