Passenger position estimation device and passenger position estimation method

Abstract

A passenger position estimation device is provided with: a transmission control unit (307) that transmits radio waves from three UWB anchor points (320) that transmit and receive the radio waves in the interior of a vehicle; a reception value acquisition unit (308) that acquires the reception intensities of the radio waves received by the UWB anchor points (320); a separation unit (309) that separates, for each passenger, a waveform indicating a plurality of time fluctuations in the reception intensity of each UWB anchor point (320); a passenger number determination unit (310) that determines the number of passengers in the room on the basis of the separated waveform; a passenger distance determination unit (311) that determines a passenger distance from each UWB anchor point (320) for each passenger corresponding to the determined number of passengers on the basis of the timing at which there is a variation specific to the person in the separated waveform; and an occupant position estimation unit (312) that estimates an occupant position for each occupant on the basis of the identified occupant distance for each occupant.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on Japanese Patent Application No. 2022-140167 filed in Japan on September 2, 2022, and the contents of the basic application are cited in their entirety by reference. Technical Field

[0003] The present disclosure relates to a passenger position estimating device and a passenger position estimating method for estimating the position of a passenger in a vehicle interior. Background Art

[0004] In many countries, all passengers in a vehicle are required to wear seat belts. As a result, vehicle manufacturers are required to install systems that warn passengers when they are not wearing seat belts. In order to warn passengers not wearing seat belts, it is necessary to detect the seat position of passengers. As a detection device for detecting the seat position, there is a known technology that uses a pressure-sensitive sensor embedded in the seat portion of the seat. However, if dedicated pressure-sensitive sensors are provided on all seats to detect the seat position, the cost increases.

[0005] In contrast, Patent Document 1 discloses a technology that attempts to detect the presence of passengers on each seat in a vehicle without using dedicated cameras and sensors. In the technology of Patent Document 1, the presence of passengers is detected by transmitting and receiving UWB (Ultra Wide Band) wireless signals between two terminals arranged in the vehicle. Specifically, based on the changes in the received power value and the delay spread value of the wireless signal, the passenger's boarding and alighting status relative to the vehicle is determined to detect the presence of passengers. In the technology of Patent Document 1, the difference in the combination of the configuration positions of the two terminals can detect the presence of passengers on each seat in the vehicle.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-186922

[0007] The changes in the received power value and delay spread value of the wireless signal in Patent Document 1 may not differ greatly between a human body and a cargo. Therefore, in the technology disclosed in Patent Document 1, when a large cargo is present in the detection range inside the vehicle instead of a human, there is a risk that the cargo may be mistakenly detected as a human. In addition, Patent Document 1 does not assume that a plurality of passengers can be detected separately. Summary of the invention

[0008] An object of the present disclosure is to provide a passenger position estimating device and a passenger position estimating method that can estimate the position of a passenger in a vehicle cabin with high accuracy and can also estimate the passenger position by distinguishing between a plurality of passengers.

[0009] The above-mentioned object is achieved by the combination of features described in the independent claims, and the dependent claims provide for further advantageous specific examples disclosed. The reference numerals in parentheses in the claims indicate the correspondence with the specific units described in the embodiments described later as one mode, and do not limit the technical scope of the present disclosure.

[0010] In order to achieve the above-mentioned purpose, the passenger position estimation device disclosed in the present invention is a passenger position estimation device for estimating the position of a passenger located in a vehicle interior, wherein the device comprises: a transmission control unit for transmitting radio waves from two or more radars that receive and send radio waves in the interior; a receiving intensity acquisition unit for respectively acquiring the receiving intensity of the radio waves received by each radar; a separation unit for separating the waveform by processing for separating the components of each passenger mixed in the waveform, wherein the waveform represents the time variation of multiple receiving intensities of each radar received by the receiving intensity acquisition unit; a number determination unit for determining the number of passengers located in the interior based on the waveform separated by the separation unit; a distance determination unit for determining the distance of the passenger from each radar according to the timing of the occurrence of human-specific changes in the waveform separated by the separation unit, according to the number of passengers determined by the number determination unit; and a passenger position estimation unit for estimating the position of the passenger in the interior according to each passenger based on the distance from each radar determined by the distance determination unit.

[0011] In order to achieve the above-mentioned purpose, the passenger position inference method of the present invention is a passenger position inference method executed by at least one processor for inferring the position of passengers located in the interior of a vehicle, and includes: a sending control process, which causes radio waves to be sent from more than two radars that receive and send radio waves in the interior; a receiving intensity acquisition process, which respectively acquires the receiving intensity of the radio waves received by each radar; a separation process, which separates the waveform by processing for separating the components of each passenger mixed in the waveform, and the above waveform represents the time variation of multiple receiving intensities of each radar received by the receiving intensity acquisition process; a number determination process, which determines the number of passengers located in the interior according to the waveform separated by the separation process; a distance determination process, which determines the distance of the passenger from each radar according to the timing of the changes unique to humans in the waveform separated by the separation process, according to the number of passengers determined by the number determination process; and a passenger position inference process, which infers the position of the passenger in the interior according to each passenger according to the distance from each radar determined by the distance determination process.

[0012] According to the above structure, the position of the passenger in the vehicle is inferred based on the distance from two or more radars to the passenger, so the passenger position can be determined with high accuracy. The waveform representing the time variation of the multiple reception intensity obtained by the radar receiving the radio wave sent from the radar in the room produces a human-specific change in the part reflected by the passenger. According to the above structure, the distance of the passenger from each radar is determined according to the timing of the human-specific change in the waveform. Therefore, the position of the passenger will not be inferred by mistaking the cargo for the passenger. From this point of view, the position of the passenger in the vehicle can also be inferred with high accuracy. In addition, the number of passengers in the room is determined based on the waveform separated by the processing for separating the components of each passenger mixed in the waveform representing the time variation of the multiple reception intensity of each radar. Therefore, the position of the passenger in the room can be inferred by each passenger using the waveform of each passenger among the multiple passengers. As a result, the position of the passenger in the vehicle can be inferred with high accuracy, and the position of the passenger can be inferred by distinguishing multiple passengers. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a diagram showing an example of a schematic configuration of a vehicle system.

[0014] Figure 2 This is a diagram showing an example of a schematic structure of a portable terminal.

[0015] Figure 3 It is a diagram showing an example of a schematic configuration of a vehicle-side unit.

[0016] Figure 4 This is a diagram showing an example of the configuration of UWB anchor points.

[0017] Figure 5 This is a diagram for explaining an example of a waveform of a pulse signal.

[0018] Figure 6 This is a diagram showing an example of temporal changes in the intensity of radio waves received by a UWB anchor point.

[0019] Figure 7 This is a schematic diagram showing an example of a path based on obtaining reflection characteristic values ​​and passage characteristic values.

[0020] Figure 8 This is a diagram showing an example of a waveform obtained by superimposing received waveforms of a plurality of pulse signals.

[0021] Fig. 9 This is a diagram for explaining an example in which unique changes of a plurality of persons are superimposed on the received waveform.

[0022] Fig.10This is a flowchart showing an example of the flow of passenger position estimation-related processing in the communication ECU.

[0023] Fig.11 This is a diagram showing an example of a schematic configuration of a vehicle system.

[0024] Fig.12 This is a diagram showing an example of a schematic structure of a portable terminal.

[0025] Fig.13 It is a diagram showing an example of a schematic configuration of a vehicle-side unit.

[0026] Fig.14 This is a diagram showing an example of the configuration of UWB anchor points.

[0027] Fig.15 This is a diagram for explaining that radio waves are blocked by a seat in a vehicle when the seat is located between a passenger and a portable terminal.

[0028] Fig.16 This is a flowchart showing an example of the flow of distance correction related processing in the communication ECU.

[0029] Fig.17 This is a flowchart showing an example of the flow of processing related to terminal position re-estimation in the communication ECU. DETAILED DESCRIPTION

[0030] A plurality of embodiments disclosed are described with reference to the accompanying drawings. In addition, for the convenience of description, between the plurality of embodiments, parts having the same functions as parts shown in the accompanying drawings used in the previous description are sometimes marked with the same reference numerals, and their descriptions are omitted. For parts marked with the same reference numerals, the descriptions in other embodiments can be referred to.

[0031] (Implementation Method 1)

[0032] <Schematic structure of vehicle system 1>

[0033] Hereinafter, this embodiment will be described using the accompanying drawings. Figure 1 As shown, the vehicle system 1 includes a portable terminal 2 and a vehicle-side unit 3 .

[0034] The portable terminal 2 is, for example, an information processing terminal such as a multifunctional mobile phone. The multifunctional mobile phone can also be referred to as a smart phone. The portable terminal 2 is carried by a user. Hereinafter, the portable terminal 2 is described as a multifunctional mobile phone.

[0035] The vehicle-side unit 3 is used in the vehicle. The details of the vehicle-side unit 3 will be described later. The vehicle using the vehicle-side unit 3 is, for example, a car for the following description. The vehicle using the vehicle-side unit 3 is referred to as the vehicle. The portable terminal 2 is carried by a passenger of the vehicle. In addition, the so-called "carried by a passenger" is not limited to the state of being carried by the passenger. It also includes the state of being placed in a place different from the passenger's seat position in the vehicle, the state of being left in the vehicle, and other states where the portable terminal 2 is not carried by the user.

[0036] <Schematic Configuration of Portable Terminal 2>

[0037] Next, use Figure 2 The portable terminal 2 is described below. Figure 2 As shown, the portable terminal 2 includes a terminal control unit 20, a BLE module 21, and a UWB module 22. In addition, in the present embodiment, for the sake of convenience, the description of the configurations of the portable terminal 2 other than the configurations related to the present disclosure is omitted.

[0038] The BLE module 21 is a communication module capable of short-range wireless communication based on Bluetooth Low Energy (Bluetooth is a registered trademark). Bluetooth Low Energy is referred to as BLE. The BLE module 21 may be configured to include, for example, an IC, an antenna, a communication circuit, etc. A communication connection is established between the BLE module 21 and the vehicle-side unit 3 for short-range wireless communication.

[0039] The BLE module 21 periodically scans and receives the advertising data packets periodically transmitted from the vehicle-side unit 3. The BLE module 21 that has received the advertising data packets transmits a connection request to the vehicle-side unit 3. When the connection request is received, the communication connection between the BLE module 21 and the vehicle-side unit 3 is established.

[0040] The UWB module 22 is a communication module capable of short-distance wireless communication in the UWB-IR (Ultra Wide Band-Impulse Radio) mode. Hereinafter, the short-distance wireless communication in the UWB-IR mode is referred to as UWB communication. UWB communication can also be referred to as ultra-wideband wireless communication. The UWB module 22 may be configured to include, for example, an IC, an antenna, a communication circuit, and the like.

[0041] The UWB module 22 performs UWB communication by sending and receiving pulse-shaped radio waves (hereinafter referred to as pulse signals). The pulse signal used in UWB communication is a signal with an extremely short pulse width. For example, it can be a signal with a pulse width of 2ns. In addition, the pulse signal used in UWB communication is a signal with a bandwidth of more than 500MHz (that is, an ultra-wide bandwidth). In addition, as frequency bands that can be used for UWB communication (hereinafter referred to as UWB frequency bands), there are 3.1GHz~10.6GHz, 3.4GHz~4.8GHz, 7.25GHz~10.6GHz, 22GHz~29GHz, etc. When the UWB module 22 receives a pulse signal sent from the vehicle-side unit 3, it replies with a response signal corresponding to the signal.

[0042] The terminal control unit 20 includes, for example, a processor, a memory, an I / O, and a bus connecting them. The terminal control unit 20 performs various processes by executing a control program stored in the memory. The terminal control unit 20 performs various processes related to the control of the transmission and reception of radio waves in the BLE module 21 and the UWB module 22. The memory mentioned here is a non-transitory tangible storage medium that non-temporarily stores programs and data that can be read by a computer. In addition, the non-transitory tangible storage medium is implemented by a semiconductor memory or the like.

[0043] <Schematic Structure of Vehicle-Side Unit 3>

[0044] Next, use Figure 3 An example of a schematic structure of the vehicle-side unit 3 is described below. Figure 3 As shown, the vehicle-side unit 3 includes a communication ECU 30, a BLE module 31, and a UWB anchor point 32. For example, the communication ECU 30 may be connected to the in-vehicle LAN 40. In addition, the BLE module 31 and the UWB anchor point 32 may be connected to the communication ECU 30.

[0045] The BLE module 31 is a communication module composed of, for example, an IC, an antenna, a communication circuit, etc. The BLE module 31 performs short-distance wireless communication based on BLE according to an instruction of the communication ECU 30 .

[0046] The UWB anchor point 32 is, for example, a communication module composed of an IC, an antenna, a communication circuit, and the like. The UWB anchor point 32 performs short-range wireless communication in the UWB-IR mode according to the instruction of the communication ECU 30. In other words, UWB communication is performed. UWB communication is performed between the UWB anchor point 32 and the portable terminal 2. The UWB anchor points 32 are arranged in multiple locations inside and outside the interior of the vehicle. For example, the UWB anchor points 32 outside the interior of the vehicle can be respectively arranged near the left and right corners of the front end and the rear end of the vehicle. The UWB anchor points 32 inside the interior of the vehicle can be, for example, arranged in three in the interior of the vehicle. The following description will be continued assuming that three UWB anchor points 32 are arranged in the interior of the vehicle.

[0047] The UWB anchor point 32 in the vehicle interior has a function as a radar. The function as a radar refers to the function of sending radio waves and receiving reflected waves from objects. The UWB anchor point 32 can realize the function as a radar by, for example, using an IC that can speed up the switching speed of sending and receiving radio waves. Hereinafter, when the UWB anchor point 32 in the vehicle interior is described separately, it is recorded as a UWB anchor point 320. The UWB anchor point 320 is equivalent to a radar and a radio wave detector. When the UWB anchor point 320 is used as a radar, it is sufficient to send a pulse signal used for UWB communication.

[0048] Here, use Figure 4 An example of arrangement of the UWB anchor point 320 in this embodiment will be described. Figure 4 321 to 323. The following is a diagram showing an example of the configuration of the UWB anchor points 320 (321 to 323). The three UWB anchor points 320 are distinguished as UWB anchor points 321, 322, and 323. The UWB anchor point 321 is configured at the front center of the interior of the vehicle. The UWB anchor point 322 is configured at the rear left side of the interior of the vehicle. The UWB anchor point 323 is configured at the rear right side of the interior of the vehicle. The UWB anchor point 320 may be configured as a structure provided in the ceiling portion of the interior of the vehicle.

[0049] The UWB anchor point 32 has a timer that measures the time (hereinafter referred to as the round-trip time) from the transmission of a pulse signal to the reception of a pulse signal as a response signal to the pulse signal. The UWB anchor point 32 measures the round-trip time by means of the timer. The UWB anchor point 32 outputs the measured round-trip time to the communication ECU 30. When the UWB anchor point 320 is used as a radar, after transmitting a pulse signal, it receives a reflected wave of the pulse signal. When the UWB anchor point 320 is used as a radar, it receives a pulse signal transmitted from another UWB anchor point 320. The UWB anchor point 320 outputs the reception strength of the received radio wave to the communication ECU 30. The reception strength of the radio wave can be expressed in other words as received signal strength, RSSI (Received Signal Strength Indication), etc.

[0050] The communication ECU 30, for example, includes a processor, a memory, an I / O, and a bus connecting them. The communication ECU 30 performs various processes by executing a control program stored in the memory. The communication ECU 30 performs various processes related to the control of the transmission and reception of radio waves in the BLE module 31 and the UWB anchor point 32. The communication ECU 30 performs processes related to the inference of the position of the portable terminal 2 relative to the vehicle. The communication ECU 30 performs processes related to the inference of the position of the passenger in the interior of the vehicle. The memory mentioned here is a non-transitory tangible storage medium that non-temporarily stores programs and data that can be read by a computer. In addition, the non-transitory tangible storage medium is implemented by a semiconductor memory or a magnetic disk, etc. The communication ECU 30 is equivalent to a passenger position inference device. In addition, the details of the communication ECU 30 are described below.

[0051] <Schematic Configuration of Communication ECU 30 >

[0052] Here, use Figure 3 An example of a schematic structure of the communication ECU 30 will be described. Figure 3As shown, the communication ECU 30 has a BLE indication unit 301, a BLE acquisition unit 302, a UWB indication unit 303, a UWB acquisition unit 304, a terminal distance inference unit 305, a terminal position inference unit 306, a transmission control unit 307, a reception value acquisition unit 308, a separation unit 309, a number determination unit 310, a passenger distance determination unit 311 and a passenger position inference unit 312 as functional modules. Executing the processing of each functional module of the communication ECU 30 by a computer is equivalent to executing the passenger position inference method. In addition, part or all of the functions performed by the communication ECU 30 can also be constituted in hardware by one or more ICs, etc. In addition, part or all of the functional modules possessed by the communication ECU 30 can also be implemented by a combination of processor-based software execution and hardware components.

[0053] The BLE indicator 301 causes the advertising data packet to be sent from the BLE module 31. For example, the BLE indicator 301 may periodically send the advertising data packet after a certain period of time has passed since the vehicle is parked and all the doors of the vehicle are locked. In addition, the end timing of the transmission of the periodic advertising data packet may be, for example, the timing of the start of the vehicle's travel.

[0054] The BLE acquisition unit 302 acquires information related to wireless communication with the portable terminal 2 received by the BLE module 31. The BLE acquisition unit 302 acquires information received by the BLE module 31 through short-range wireless communication with the BLE module 21. This process can be performed when the BLE module 21 of the portable terminal 2 that has received the advertising data packet and the BLE module 31 have established a connection.

[0055] The UWB indicator unit 303 causes a pulse signal to be sent from the UWB anchor point 32. As an example, pulse signals are sent in sequence from a plurality of UWB anchor points 32 provided in the vehicle. The UWB indicator unit 303 starts sending pulse signals by triggering the establishment of the above-mentioned connection or the establishment of the connection. Accordingly, it is possible to suppress waste of sending pulse signals from the UWB anchor point 32 even when there is no portable terminal 2 around the vehicle. The UWB indicator unit 303 determines, for example, that the above-mentioned connection is established or has been established based on the information obtained by the BLE acquisition unit 302. With regard to establishing a connection, it can be determined based on the BLE module 31 receiving a connection request sent from the BLE module 21. With regard to whether a connection has been established, it can be determined based on the information sent by the BLE module 31 through the short-range wireless communication performed by establishing a connection.

[0056] The UWB acquisition unit 304 acquires information related to UWB communication received by the UWB anchor point 32. UWB communication is performed between the UWB module 22 of the portable terminal 2 and the UWB anchor point 32. The UWB acquisition unit 304 acquires round trip time output from each of a plurality of UWB anchor points 32 provided in the vehicle.

[0057] The terminal distance estimation unit 305 estimates the distance from the UWB anchor point 32 to the portable terminal 2 based on the pulse signal that can be sent and received between the portable terminal 2 and the UWB anchor point 32. The distance from the UWB anchor point 32 to the portable terminal 2 is referred to as the terminal distance below. The terminal distance estimation unit 305 estimates the terminal distance for each of the multiple UWB anchor points 32 that can receive the response signal. The terminal distance estimation unit 305 can estimate the terminal distance using the round-trip time acquired by the UWB acquisition unit 304. In detail, the value obtained by subtracting the internal processing time of the portable terminal 2 in the UWB communication from the round-trip time is divided by 2 to calculate the propagation time. Then, the value obtained by multiplying the calculated propagation time by the speed of light can be estimated as the terminal distance. In addition, regarding the internal processing time, it is sufficient to store a standard value in the non-volatile memory of the communication ECU 30 in advance.

[0058] The terminal position estimation unit 306 estimates the position of the portable terminal 2 relative to the vehicle using the terminal distance estimated by the terminal distance estimation unit 305. The position of the portable terminal 2 relative to the vehicle is referred to as the terminal position below. The terminal position estimation unit 306 estimates the terminal position using the above-mentioned terminal distances about the three UWB anchor points 32. Regarding the selection of the three UWB anchor points 32, three anchor points with shorter terminal distances can be selected. As an example of estimating the terminal position, it can be as follows.

[0059] First, in a coordinate system of a horizontal plane with the reference point of the vehicle as the origin (hereinafter referred to as a plane coordinate system), three circles are drawn with the respective positions of the three UWB anchor points 32 as the center and the terminal distance as the radius. Then, based on the three circles, the terminal position is inferred by three-point positioning. Three-point positioning can also be referred to as triangulation. The reference point of the vehicle can be appropriately determined. As an example, it can be set to the position in the center of the vehicle width direction of the rear axle. The position of the UWB anchor point 32 relative to the vehicle can be used by pre-storing it in the non-volatile memory of the communication ECU 30. The terminal position inference unit 306 outputs the inferred terminal position to the in-vehicle LAN 40. The terminal position is used, for example, for notification that a digital key system or a portable terminal 2 has fallen into the vehicle interior.

[0060] The transmission control unit 307 transmits radio waves from three UWB anchor points 320 as a radar function. In the example of this embodiment, a pulse signal used for UWB communication is transmitted. The transmission control unit 307 switches the UWB anchor points 320 that operate at a predetermined cycle so that interference does not occur between the UWB anchor points 320.

[0061] The transmission control unit 307 transmits radio waves with different transmission signal strengths multiple times at a transmission time shorter than the transmission period during the transmission period allocated to each UWB anchor point 320 (see Figure 5 ). Figure 5 3 is a diagram showing an example of a pulse waveform of a pulse signal transmitted from the UWB anchor point 320. Figure 5 As shown in FIG. 1 , the envelope formed by the transmission signal strength of the pulse signal becomes a mountain shape. In other words, the transmission signal strength is the lowest at the beginning and the end of the transmission period, and the transmission signal strength is the highest in the middle of the transmission period. The transmission control unit 307 transmits multiple times during the transmission period. Figure 5 The transmission interval at this time is set to be sufficiently small relative to the breathing and body movement cycle of a person. The transmission interval can be set to every 100ms, for example. The following will further explain the case where the transmission interval is every 100ms. The processing in the transmission control unit 307 is equivalent to the transmission control process.

[0062] The reception value acquisition unit 308 acquires the reception intensity of the radio waves received by each UWB anchor point 320. In the example of the present embodiment, the reception values ​​received by the UWB anchor points 321, 322, and 323 are acquired. The reception value is at least the reception intensity of the received radio waves. The reception value may also include, for example, the arrival time of the radio waves, the frequency of the radio waves, the signals included in the radio waves, etc. The reception value acquisition unit 308 is equivalent to the reception intensity acquisition unit. In addition, the processing in the reception value acquisition unit 308 is equivalent to the reception intensity acquisition process. The arrival time of the radio waves is the arrival time of the radio waves after the pulse signal is sent in the UWB anchor point 320. For example, for the radio waves received by the UWB anchor point 321 during the transmission period of the UWB anchor point 321, the transmission of the pulse signal in the UWB anchor point 321 becomes the reference. For the radio waves received by the UWB anchor point 322 during the transmission period of the UWB anchor point 321, the transmission of the pulse signal in the UWB anchor point 321 also becomes the reference. Regarding the radio waves received by the UWB anchor point 322 during the transmission period of the UWB anchor point 322 , the transmission of the pulse signal in the UWB anchor point 322 serves as a reference.

[0063] Here, use Figure 6 , which shows an example of the time variation of the intensity of the radio wave received by the UWB anchor point 320. Figure 6In the figure, the intensity of the received radio wave is shown from the time the pulse signal is sent to the time 20ns have passed. Figure 6 As shown in FIG. 1 , as a waveform, a waveform obtained by synthesizing the waveforms reflected and returned from various obstacles can be obtained. Figure 6 In the example shown, there are four hills, so there are likely to be obstacles at four locations.

[0064] Preferably, the reception value acquisition unit 308 separately acquires the reflection characteristic value and the pass characteristic value as the reception intensity. Accordingly, even when the number of UWB anchor points 320 is less than the number of passengers in the vehicle, the components of each passenger can be separated with high accuracy by the separation unit 309 described later. The reflection characteristic value is the reception intensity when the radio wave transmitted from the UWB anchor point 320 is received by the UWB anchor point 320 among each UWB anchor point 320. The pass characteristic value is the reception intensity when the UWB anchor point 320 among each UWB anchor point 320 receives the radio wave transmitted from other UWB anchor points 320 other than the UWB anchor point 320. The reception value acquisition unit 308 can distinguish the reflection characteristic value and the pass characteristic value based on the combination of the UWB anchor point 320 that transmits the radio wave at a certain timing and the UWB anchor point 320 that receives the reflected wave.

[0065] Here, use Figure 7 The reflection characteristic value and the transmission characteristic value are described. Figure 7 FIG. 1 is a schematic diagram showing an example of a path for obtaining a reflection characteristic value and a path for passing the characteristic value. Figure 7 In the description, a case where a radio wave transmitted by the UWB anchor point 321 is received by the UWB anchor point 321 and the UWB anchor point 322 is taken as an example. Figure 7 The solid line indicated by R indicates a path of the radio wave transmitted from the UWB anchor point 321 until it is received by the UWB anchor point 321 . Figure 7 The dotted line indicated by T represents a path of the radio wave transmitted from the UWB anchor point 321 until it is received by the UWB anchor point 322 . Figure 7 P represents a passenger. The reflection characteristic value is the reception intensity of the reflected wave obtained by the reflection of the radio wave sent by the UWB anchor point 321 and received by the same UWB anchor point 321. The passing characteristic value is the reception intensity of the reflected wave obtained by the reflection of the radio wave sent by the UWB anchor point 321 and received by the other UWB anchor points 322.

[0066] The receiving value acquisition unit 308 combines the reflection characteristic value and the through characteristic value to obtain the same number of types as the capacity of the vehicle. In the example of the present embodiment, the case where the capacity of the vehicle is 5 people is cited for explanation. The receiving value acquisition unit 308 obtains, for example, three types of reflection characteristic values ​​and two types of through characteristic values. The first type of reflection characteristic value is the reception intensity when the UWB anchor point 321 receives the radio wave sent from the UWB anchor point 321. The second type of reflection characteristic value is the reception intensity when the UWB anchor point 322 receives the radio wave sent from the UWB anchor point 322. The third type of reflection characteristic value is the reception intensity when the UWB anchor point 323 receives the radio wave sent from the UWB anchor point 323. The first type of through characteristic value is the reception intensity when the UWB anchor point 322 receives the radio wave sent from the UWB anchor point 321. The second type of through characteristic value is the reception intensity when the UWB anchor point 323 receives the radio wave sent from the UWB anchor point 321.

[0067] Here, the method of estimating the passenger position as a premise is described. The waveform of the time variation of the reception intensity acquired by the reception value acquisition unit 308 (hereinafter, the reception waveform) is as follows: Figure 6 As shown. The set of received waveforms obtained by sending multiple pulse signals at intervals sufficiently small relative to the human breathing and body movement cycle becomes Figure 8 The set of waveforms shown in FIG. 1 shows a collection of waveforms. A person breathes and moves his body relative to a non-living object such as a cargo. Therefore, changes unique to humans such as breathing and body movement occur in the waveforms received multiple times. Figure 8 The change shown in FL represents a change that is unique to a person (hereinafter, unique change). The timing of the start of this unique change is regarded as the timing when the pulse signal is reflected by the human body, so that the distance from the UWB anchor point 320 to the passenger can be determined. The distance from the UWB anchor point 320 to the passenger is referred to as the passenger distance. Based on the passenger distance determined for two or three UWB anchor points 320, the passenger position is estimated through two-point positioning or three-point positioning. Figure 4 RC represents an example of a ranging circle based on the passenger distance determined for each UWB anchor point 320. In addition, in the case of two-point positioning, the two-point passenger position is inferred. Therefore, in the case of two-point positioning, the two UWB anchor points 320 are configured so that one of the inferred passenger positions is definitely outside the vehicle. Thus, even in two-point positioning, the passenger position inside the vehicle can be reduced to one point for inference. In addition, the method of inferring the passenger position by three-point positioning can more easily infer the passenger position with high accuracy.

[0068] According to the above structure, the position of the passenger can be determined with high accuracy. In addition, according to the above structure, the distance of the passenger from each UWB anchor point 320 is determined based on the timing of the occurrence of the unique change. Therefore, the position of the passenger will not be inferred by mistaking cargo for passengers. From this point of view, the position of the passenger in the interior of the vehicle can also be inferred with high accuracy.

[0069] When there is only one passenger in the vehicle, the above-mentioned inference method can be used to infer the passenger position of the one passenger, but the number of passengers in the vehicle is not limited to one person. Consider determining the number of passengers based on the number of regions that produce unique changes in the received waveform. However, there are cases where it is difficult to determine the number of passengers based on the number of regions that produce unique changes in the received waveform. For example, there is a case where the distances from the UWB anchor point 320 to multiple passengers are equal. In addition, there is also a case where the unique changes of multiple passengers overlap due to the influence of multipath. In such a case, Fig. 9 As shown, the changes that appear to be unique to one person actually overlap with the changes that are unique to multiple people. Fig. 9 A+B represents the waveform after the unique changes of multiple people are overlapped. Fig. 9 A and B respectively represent waveforms of unique changes of different passengers. In order to easily determine the number of passengers for such a problem, the following processing in the separation unit 309 is performed.

[0070] The separation unit 309 separates the waveform representing the time variation of the multiple reception intensities of each UWB anchor point 320 by a process for separating the components of each passenger mixed in the waveform. The process in the separation unit 309 is equivalent to the separation process. The multiple reception intensities of each UWB anchor point 320 use the intensities received by the reception value acquisition unit 308. As the reception intensity, it is preferred to use a reflection characteristic value and a pass characteristic value. As a process for separating the components of each passenger mixed in the waveform, independent component analysis can be used. In addition, the components of each passenger mixed in the waveform can also be separated by a process other than independent component analysis. The following will continue to explain the case of separating the components of each passenger mixed in the waveform by independent component analysis. The waveform separated in the separation unit 309 will be referred to as a separated waveform.

[0071] When independent component analysis is used, the input waveform becomes a waveform representing the time variation of the receiving intensity received by the receiving value acquisition unit 308. The output waveform becomes a waveform obtained by separating the input waveform into the number of input waveforms by independent component analysis. Generally speaking, the number of input waveforms needs to be the same as the number of output waveforms. For example, in the example of the present embodiment, the capacity of the vehicle is 5 people, so the maximum number of passengers in the vehicle is 5. Therefore, in order to obtain the output waveform of the maximum number of passengers of 5 people, the input waveform also needs to be five. In contrast, in the present embodiment, as the receiving intensity, not only the reflection characteristic value but also the through characteristic value is used. Therefore, even when the number of UWB anchor points 320 is less than the capacity of the vehicle, the input waveform of the number of the capacity can be prepared. Therefore, although the number of UWB anchor points 320 set to the vehicle is suppressed, it is easy to determine the number of passengers in the vehicle. In addition, when the capacity of the vehicle is less than 3 people, it can also be configured to use only the reflection characteristic value as the receiving intensity.

[0072] As the receiving waveform in the UWB anchor point 320, as the time becomes later, the multipath overlaps, and the receiving waveform after the unique fluctuations of all passengers in the vehicle are overlapped. Therefore, the receiving value acquisition unit 308 can draw the receiving waveform after the pulse signal is sent every 100ms, which is inferred to be the time when the overlapping receiving waveform begins to be obtained. Thus, the receiving value acquisition unit 308 obtains the receiving waveform as the object. This receiving waveform is a receiving waveform that the breathing of all passengers in the vehicle should be synthesized, so it is possible to use the receiving waveform of each UWB anchor point 320 and separate it according to each passenger through independent component analysis. In the following, the time when it is inferred that the overlapping receiving waveform begins to be obtained is called the object time. The object time is the time when the receiving waveform of the passenger in the seat farthest from the UWB anchor point 320 as the object is inferred to be obtained.

[0073] The number determination unit 310 determines the number of passengers in the interior of the vehicle based on the separated waveforms. The processing in the number determination unit 310 is equivalent to the number determination process. The number determination unit 310 groups the waveforms of the number of passengers of the vehicle separated in the separation unit 309. Regarding the grouping, for example, a threshold is set by a correlation coefficient, and the related waveforms above the threshold are set as the waveforms of the same person. And the number of people separated by grouping can be determined as the number of passengers in the interior of the vehicle.

[0074] The passenger distance determination unit 311 determines the passenger distance based on the timing of the unique change in the separation waveform. The passenger distance determination unit 311 determines the passenger distance for each passenger corresponding to the number of passengers determined by the number determination unit 310. The passenger distance determination unit 311 is equivalent to the distance determination unit. In addition, the processing in the passenger distance determination unit 311 is equivalent to the passenger distance determination process. The passenger distance determination unit 311 can also use changes unique to body motion as the unique change, but it is preferred to use changes unique to breathing. This is because changes in the waveform based on breathing are easier to distinguish from cargo than changes in the waveform based on body motion, and reliability is improved.

[0075] The passenger distance determination unit 311 may determine the timing of the occurrence of a characteristic change, for example, for the waveform before separation by the separation unit 309. The passenger distance determination unit 311 may determine the timing of the occurrence of a characteristic change based on the frequency characteristics corresponding to the characteristic change, etc. The passenger distance determination unit 311 determines which of the waveforms separated by the separation unit 309 is used to form the waveform of the part where the characteristic change occurs. This determination may be performed, for example, using multiple regression analysis, etc. Next, the timing of the start of the characteristic change is determined for the separated waveforms that are grouped as waveforms of different characters in the separated waveforms. Moreover, the passenger distance may be determined by TOF (Time of Flight) based on the time from the transmission of the pulse signal to the timing. In addition, the accuracy of the passenger distance determined by the received waveform is poor compared to the reflection characteristic value by the characteristic value. Therefore, it is preferred to use the reflection characteristic value to determine the passenger distance.

[0076] The passenger position estimation unit 312 estimates the passenger position for each passenger based on the passenger distance from each UWB anchor point 320 determined by the passenger distance determination unit 311. The processing in the passenger position estimation unit 312 corresponds to the passenger position estimation step. Specifically, similar to the estimation of the terminal position, the passenger position of each passenger is estimated by three-point positioning based on the three passenger distances to the UWB anchor points 321, 322, and 323 of each passenger.

[0077] According to the above configuration, the position of the passenger in the vehicle can be estimated for each passenger using the waveforms of the plurality of passengers. As a result, the position of the passenger in the vehicle can be estimated with high accuracy, and the position of the passenger can be estimated by distinguishing a plurality of passengers.

[0078] <Processing Related to Passenger Position Estimation in Communication ECU 30>

[0079] Next, use Fig.10 An example of the flow of processing related to the estimation of the passenger position (hereinafter referred to as passenger position estimation related processing) in the communication ECU 30 will be described with reference to the flowchart of FIG. Fig.10 The flowchart may be configured to be repeatedly executed periodically when the power switch of the vehicle is turned on. The power switch is a switch for starting the internal combustion engine or the motor generator of the vehicle.

[0080] First, in step S1, the transmission control unit 307 transmits a pulse signal multiple times from the UWB anchor point 320. The transmission interval is, for example, every 100 ms. In S1, a pulse signal is transmitted from only one of the three UWB anchor points 320. In step S2, the reception value acquisition unit 308 acquires a reception waveform as a target. Specifically, a waveform is acquired by plotting the reception waveform after the target time after the pulse signal is transmitted from the UWB anchor point 320 every 100 ms.

[0081] In step S3, when all three UWB anchor points 320 have completed the transmission of pulse signals ("Yes" in S3), the process proceeds to step S4. On the other hand, when there is a UWB anchor point 320 that has not completed the transmission of pulse signals ("No" in S3), the process returns to S1 and repeats the process. In this case, the transmission of pulse signals from the UWB anchor point 320 in the next order is performed in the predetermined transmission order. As an example, the transmission order may be the order of UWB anchor point 321, UWB anchor point 322, and UWB anchor point 323.

[0082] In the example of this embodiment, when a pulse signal is transmitted from the UWB anchor point 321, in S2, the received waveforms of the UWB anchor points 321, 322, and 323 are acquired as targets. When a pulse signal is transmitted from the UWB anchor point 322, in S2, the received waveform of the UWB anchor point 322 is acquired as targets. When a pulse signal is transmitted from the UWB anchor point 323, in S2, the received waveform of the UWB anchor point 323 is acquired as targets.

[0083] In step S4, the separation unit 309 separates the waveform acquired in S3. The separation can be performed, for example, by independent component analysis. In step S5, the number determination unit 310 determines the number of passengers located in the interior of the vehicle based on the separation waveform separated in S4. In step S6, the passenger distance determination unit 311 determines the passenger distance based on the timing of the unique changes in the separation waveform separated in S4. In S6, the passenger distance is determined for each passenger corresponding to the number of passengers determined in S5. In step S7, the passenger position inference unit 312 infers the position of the passenger in the interior of the vehicle for each passenger based on the distance of each passenger from each UWB anchor point 320 determined in S6. Then, the passenger position inference related processing is terminated.

[0084] (Implementation Method 2)

[0085] The structure of the embodiment 1 is not limited thereto, and the structure of the following embodiment 2 may be used. Hereinafter, an example of the structure of the embodiment 2 will be described with reference to the drawings.

[0086] <Schematic Configuration of Vehicle System 1a>

[0087] Hereinafter, this embodiment will be described using the accompanying drawings. Fig.11 As shown, the vehicle system 1a includes a portable terminal 2a and a vehicle-side unit 3a. The portable terminal 2a will be described in detail later. The vehicle-side unit 3a will be described in detail later.

[0088] <Schematic Configuration of Portable Terminal 2a>

[0089] Next, use Fig.12 The portable terminal 2a is described below. Fig.12 As shown, the portable terminal 2a includes a terminal control unit 20a, a BLE module 21, and a UWB module 22a. The portable terminal 2a is the same as the portable terminal 2 of the first embodiment except that the terminal control unit 20a is replaced with the terminal control unit 20.

[0090] The UWB module 22a is the same as the UWB module 22 of Embodiment 1 except that it must have the function of the above-mentioned radar. The UWB module 22a can realize the function of the radar by, for example, using an IC that can speed up the switching speed of the transmission and reception of radio waves. Therefore, the portable terminal 2a equipped with the UWB module 22a is equivalent to a radar. When the portable terminal 2a is used as a radar, it is sufficient to send a pulse signal used for UWB communication.

[0091] The terminal control unit 20a is the same as the terminal control unit of embodiment 1 except that some processing is different. The terminal control unit 20a enables the UWB module 22a to function as a radar according to the instruction from the vehicle side unit 3a. That is, as a function of the radar, radio waves are sent from the UWB module 22a. In the example of this embodiment, a pulse signal used for UWB communication is sent. The terminal control unit 20a can obtain instructions from the vehicle side unit 3a via the BLE module 21. The terminal control unit 20a obtains the reception intensity of the reflected wave of the radio wave sent as a function of the radar. In the example of this embodiment, the reception value received by the UWB module 22a is obtained. The reception value is at least the reception intensity of the received radio wave. The reception value may also include, for example, the arrival time of the radio wave, the frequency of the radio wave, the signal included in the radio wave, etc. The terminal control unit 20a causes the reception value received by the UWB module 22a to be sent to the vehicle side unit 3a. This transmission can also be performed by any one of the BLE module 21 and the UWB module 22a.

[0092] <Schematic Structure of Vehicle-Side Unit 3a>

[0093] Next, use Fig.13 An example of a schematic structure of the vehicle-side unit 3a is described below. Fig.13 As shown, the vehicle-side unit 3a includes a communication ECU 30a, a BLE module 31, and a UWB anchor point 32a. The vehicle-side unit 3a includes the communication ECU 30a instead of the communication ECU 30. The vehicle-side unit 3a includes a UWB anchor point 32a instead of the UWB anchor point 32. The vehicle-side unit 3a is the same as the vehicle-side unit 3 of the first embodiment except for these points.

[0094] The UWB anchor point 32a is the same as the UWB anchor point 32 of Embodiment 1 except that the installation method in the vehicle is different. Specifically, the installation method of the UWB anchor point 320a as the UWB anchor point 32a in the vehicle cabin is different from that of the UWB anchor point 320 of Embodiment 1.

[0095] Here, use Fig.14 An example of the arrangement of the UWB anchor point 320 a in this embodiment will be described. Fig.14 320a (321, 324). In the present embodiment, two UWB anchor points 320a are provided in the vehicle. In the following, the two UWB anchor points 320a are distinguished as UWB anchor points 321 and 324 for representation. The UWB anchor point 321 is arranged at the front center of the vehicle interior as in the first embodiment. The UWB anchor point 324 is arranged at the rear center of the vehicle interior. The UWB anchor point 320a may be configured to be arranged at the ceiling portion of the vehicle interior. The UWB anchor point 320a is also equivalent to a radar and a radio wave detector.

[0096] The communication ECU 30a is the same as the communication ECU 30 of the first embodiment except that some processing is different. The communication ECU 30a also corresponds to the passenger position estimation device. The details of the communication ECU 30a are described below.

[0097] <Schematic Configuration of Communication ECU 30a>

[0098] Here, use Fig.13 An example of a schematic structure of the communication ECU 30a will be described. Fig.13As shown, the communication ECU 30a includes a BLE instruction unit 301a, a BLE acquisition unit 302, a UWB instruction unit 303, a UWB acquisition unit 304, a terminal distance estimation unit 305, a terminal position estimation unit 306, a transmission control unit 307a, a reception value acquisition unit 308a, a separation unit 309, a number of people determination unit 310, a passenger distance determination unit 311a, a passenger position estimation unit 312a, and a correction unit 313 as functional modules. The communication ECU 30a includes a BLE instruction unit 301a instead of the BLE instruction unit 301. The communication ECU 30a includes a transmission control unit 307a instead of the transmission control unit 307. The communication ECU 30a includes a reception value acquisition unit 308a instead of the reception value acquisition unit 308. The communication ECU 30a includes a passenger distance determination unit 311a instead of the passenger distance determination unit 311. The communication ECU 30a includes a passenger position estimation unit 312a instead of the passenger position estimation unit 312. The communication ECU 30a includes a correction unit 313. Except for these points, the communication ECU 30a is the same as the communication ECU 30 of Embodiment 1. The execution of the processing of each functional block of the communication ECU 30a by a computer is equivalent to the execution of the passenger position estimation method.

[0099] The BLE indicator 301a is the same as the BLE indicator 301 of Embodiment 1 except that some processing is different. The processing different from the BLE indicator 301 is described below. The BLE indicator 301a causes the UWB module 22a to transmit radio waves as a radar function. The BLE indicator 301a performs this processing according to the instruction of the transmission control unit 307a.

[0100] The transmission control unit 307a causes radio waves to be transmitted from the two UWB anchor points 320a and the portable terminal 2a as a radar function. That is, the portable terminal 2a is used as a radar. The portable terminal 2a used as a radar may be, for example, a portable terminal 2a registered as a key of the vehicle in the digital key system. In addition, it is assumed that the portable terminal 2a is a portable terminal 2a brought into the vehicle. The communication ECU 30a can determine whether it is a portable terminal 2a brought into the vehicle based on the terminal position estimated by the terminal position estimation unit 306. In the example of this embodiment, a pulse signal used for UWB communication is transmitted. The transmission control unit 307a is the same as the transmission control unit 307 of the embodiment 1 except that the radio waves are transmitted from the portable terminal 2a as a radar function. The transmission control unit 307 switches the transmission source of the radio waves at a predetermined period so that no interference occurs between each UWB anchor point 320a and the portable terminal 2a.

[0101] The reception value acquisition unit 308a respectively acquires the reception intensity of the radio waves received by each UWB anchor point 320a and the portable terminal 2a. In the example of this embodiment, the reception values ​​received by the UWB anchor points 321 and 324 are acquired. In addition, the reception value received by the portable terminal 2a is acquired. The reception value acquisition unit 308a can acquire the reception value received by the portable terminal 2a via the BLE module 31 and the BLE acquisition unit 302. The reception value acquisition unit 308a is the same as the reception value acquisition unit 308 of embodiment 1 except that it also acquires the reception intensity of the radio waves received by the portable terminal 2a. The reception value acquisition unit 308a is also equivalent to the reception intensity acquisition unit. In addition, the processing in the reception value acquisition unit 308a is also equivalent to the reception intensity acquisition process. The radio wave arrival time in the reception value is the radio wave arrival time from the transmission of the pulse signal in the portable terminal 2a with respect to the portable terminal 2a.

[0102] The passenger distance determination unit 311a is the same as the passenger distance determination unit 311 of Embodiment 1 except that it also determines the passenger distance with respect to the portable terminal 2a. The passenger distance determination unit 311a also corresponds to the distance determination unit. In addition, the processing in the passenger distance determination unit 311a also corresponds to the passenger distance determination step.

[0103] The passenger position estimation unit 312a estimates the passenger position for each passenger based on the passenger distance from each UWB anchor point 320a and the portable terminal 2a determined by the passenger distance determination unit 311. The passenger position estimation unit 312a is the same as the passenger position estimation unit 312 of the first embodiment, except that the passenger distance from each passenger to the portable terminal 2a is also used. The processing in the passenger position estimation unit 312a is also equivalent to the passenger position estimation process. Specifically, the passenger position of each passenger is estimated by three-point positioning based on the three passenger distances from each passenger to the UWB anchor points 321, 324 and the portable terminal 2a. In this case, for the ranging circle of the portable terminal 2a, the position of the portable terminal 2a relative to the vehicle is used. For the position of the portable terminal 2a relative to the vehicle, the terminal position estimated by the terminal position estimation unit 306 can be used.

[0104] According to the structure of the second embodiment, by using the portable terminal 2a as a radar, the number of UWB anchor points 320a installed in the vehicle can be suppressed to a small number. In other words, the number of radars installed in the vehicle can be suppressed to a small number. For example, the cost of the UWB anchor point 320a with a radar function is high compared to the UWB anchor point 32 without a radar function. This is because an IC that can speed up the switching speed of the transmission and reception of radio waves is required. In contrast, according to the structure of the second embodiment, the number of radars installed in the vehicle is suppressed to a small number, and the cost of the vehicle can be suppressed. In addition, even with the structure of the second embodiment, it is possible to use the waveforms of multiple passengers in the same way as in the first embodiment to infer the position of the passenger in the interior of the vehicle according to each passenger. Therefore, the position of the passenger in the interior of the vehicle can be inferred with high accuracy, and the position of the passenger can also be inferred by distinguishing multiple passengers.

[0105] The correction unit 313 preferably corrects the distance from the portable terminal 2a to the passenger determined by the passenger distance determination unit 311a. In other words, it is preferred to correct the passenger distance with respect to the portable terminal 2a. This is because the passenger distance with respect to the portable terminal 2a (hereinafter referred to as the terminal-passenger distance) is determined to be longer than the true value according to the position of the portable terminal 2a in the vehicle. More specifically, as follows.

[0106] like Fig.15 As shown, when the seat of the vehicle is located between the passenger and the portable terminal 2a, the radio wave is shielded by the seat. In this case, the radio wave is transmitted and received by bypassing the seat, and the arrival time of the radio wave becomes longer accordingly. Therefore, the terminal-passenger distance determined by TOF is longer than the true value. Fig.15 The Sh stands for seat. Fig.15 The P stands for passenger. Fig.15 TV represents the true value of the terminal passenger distance. Fig.15 FV represents the terminal passenger distance determined by the passenger distance determination unit 311a.

[0107] The longer the distance that the radio wave detours, the lower the reception intensity of the reflected wave from the passenger (hereinafter, the reflection reception intensity). Therefore, even if the terminal passenger distance is the same, the longer the distance that the radio wave detours, the lower the reflection reception intensity is obtained. Therefore, the terminal passenger distance is corrected according to the error between the ideal and the actual correspondence between the terminal passenger distance and the reflection reception intensity. The ideal correspondence between the terminal passenger distance and the reflection reception intensity (hereinafter, the ideal relationship) can be set in advance by simulation or the like. The ideal relationship is the correspondence between the true value of the terminal passenger distance in free space and the reflection reception intensity. The ideal relationship can be used by pre-storing in the non-volatile memory of the communication ECU10a. The actual correspondence between the terminal passenger distance and the reflection reception intensity (hereinafter, the actual relationship) is the correspondence between the terminal passenger distance determined by the passenger distance determination unit 311a and the reception intensity of the radio wave corresponding to the point on the waveform used to determine the distance. The correction unit 313 corrects the distance to be shorter in response to the weakening of the reflection reception intensity compared with the ideal relationship for the terminal passenger distance determined by the passenger distance determination unit 311a. As an example, a correction of 3 cm is sufficient for every 1 db.

[0108] The passenger position estimation unit 312a estimates the passenger position for each passenger using the distance corrected by the correction unit 313 for the passenger distance from the portable terminal 2a determined by the passenger distance determination unit 311a. In this way, the passenger position can be estimated with higher accuracy. In the passenger position estimation related processing of the second embodiment, the UWB anchor point 320 can be replaced by the UWB anchor point 320a. In addition, one UWB anchor point 320 can be replaced by the portable terminal 2a.

[0109] <Distance Correction Related Processing in Communication ECU 30a>

[0110] Here, use Fig.16 An example of the flow of processing related to correction of the terminal passenger distance (hereinafter referred to as distance correction related processing) in the communication ECU 30a will be described with reference to the flowchart of FIG. Fig.16 The flowchart may be configured to start, for example, when the terminal passenger distance is determined by the passenger distance determination unit 311a.

[0111] First, in step S21, the correction unit 313 compares the reflected reception intensity in the actual relationship with the reflected reception intensity in the ideal relationship. The actual relationship in this case is the correspondence between the terminal passenger distance determined by the passenger distance determination unit 311a and the reception intensity of the radio wave corresponding to the point on the waveform used to determine the distance.

[0112] In step S22, when the correction unit 313 determines that there is a difference between the reflected reception intensity in the actual relationship and the reflected reception intensity in the ideal relationship ("Yes" in S22), the process moves to step S23. On the other hand, when the correction unit 313 determines that there is no difference ("No" in S22), the distance correction related processing ends. When the reflected reception intensity in the actual relationship and the reflected reception intensity in the ideal relationship have a difference of more than a certain value, the correction unit 313 can determine that there is a difference. The difference of more than a certain value can be a difference of more than the deviation of the value of the error degree.

[0113] In step S23, the correction unit 313 corrects the terminal passenger distance to be shorter in response to the reflection reception intensity of the actual relationship being lower than the ideal relationship. Then, the distance correction related processing is terminated. After the distance correction related processing is terminated, the passenger position estimation unit 312a estimates the passenger position. In the case where the terminal passenger distance is corrected in the distance correction related processing, the passenger position estimation unit 312a estimates the passenger position using the corrected terminal passenger distance. In the case where the terminal passenger distance is not corrected in the distance correction related processing, the passenger position estimation unit 312a estimates the passenger position using the uncorrected terminal passenger distance.

[0114] <Terminal position re-estimation related processing in the communication ECU 30a>

[0115] Sometimes the position of the portable terminal 2a is different from the position of the UWB anchor point 320a, and may change while the vehicle is traveling. Therefore, when the position of the portable terminal 2a changes, it is preferable to estimate the terminal position again. When the position of the portable terminal 2a changes, the reflection reception intensity obtained from the same passenger to the portable terminal should also change. Therefore, the communication ECU 30a can use the change of the reflection reception intensity as a trigger to estimate the terminal position again.

[0116] Here, use Fig.17 The flowchart of will now be described as an example of a process related to the re-estimation of the terminal position (hereinafter referred to as the terminal position re-estimation related process) in the communication ECU 30a. Fig.17 For example, the flowchart may be configured to start each time a reception value is acquired by the reception value acquisition unit 308a.

[0117] First, in step S41, the terminal position estimation unit 306 compares the reception intensity obtained from the portable terminal 2a this time through the reception value acquisition unit 308a with the reception intensity of the last time. In step S42, when the terminal position estimation unit 306 determines that there is a difference between the reception intensity this time and the last time ("Yes" in S42), it moves to step S43. On the other hand, when the terminal position estimation unit 306 determines that there is no difference ("No" in S42), the terminal position re-estimation related processing ends. When there is a difference of more than a certain value between the reception intensity this time and the last time, the terminal position re-estimation related processing can be determined as having a difference. The difference of more than a certain value can be a difference of more than the deviation of the value of the error degree.

[0118] In step S43, the terminal position estimation unit 306 starts to estimate the terminal position again. Then, the terminal position re-estimation related processing ends. When starting to estimate the terminal position again, the UWB instruction unit 303 can send a pulse signal from the UWB anchor point 32. Then, the terminal distance can be determined and the terminal position can be estimated in the future.

[0119] According to the above configuration, even when the position of the portable terminal 2a changes, the passenger position can be estimated with high accuracy using the portable terminal 2a. In addition, if the terminal position estimation unit 306 does not determine that there is a difference in the reception strength, the passenger position is not estimated again. Therefore, compared with the configuration of periodically re-estimating the passenger position, waste of processing can be suppressed. Therefore, it is possible to estimate the passenger position with high accuracy using the portable terminal 2a while suppressing waste of processing.

[0120] (Implementation 3)

[0121] In Embodiment 2, a configuration is shown in which one portable terminal 2a is used as a radar to estimate the position of a passenger, but the present invention is not necessarily limited to this. For example, it is also possible to configure such that two or more portable terminals 2a are used as radars to estimate the position of a passenger (hereinafter referred to as Embodiment 3). It is assumed that the two or more portable terminals 2a are portable terminals 2a brought into the vehicle. According to Embodiment 3, the number of portable terminals 2a that can be used as radars increases, and accordingly, the position of a passenger can be estimated with further high accuracy.

[0122] (Implementation 4)

[0123] In the above-mentioned embodiment, the communication ECU 30, 30a is shown to be responsible for the processing related to the estimation of the passenger position, but it is not necessarily limited to this. For example, the communication ECU 30, 30a and another ECU may be responsible for the processing related to the estimation of the passenger position. In addition, the ECU different from the communication ECU 30, 30a may be responsible for the processing related to the estimation of the passenger position.

[0124] In addition, the present disclosure is not limited to the above-mentioned embodiments, and various changes can be made within the scope indicated by the claims. The embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. In addition, the control unit and the method thereof described in the present disclosure may also be implemented by a special-purpose computer, which is composed of a processor programmed to execute one or more functions concretized by a computer program. Alternatively, the device and the method thereof described in the present disclosure may also be implemented by a special-purpose hardware logic circuit. Alternatively, the device and the method thereof described in the present disclosure may also be implemented by one or more special-purpose computers, which are composed of a combination of a processor that executes a computer program and one or more hardware logic circuits. In addition, the computer program may also be stored as an instruction executed by a computer in a computer-readable non-transient tangible recording medium.

[0125] (Disclosed technical ideas)

[0126] This specification discloses multiple technical ideas recorded in the following multiple items. Sometimes, several items are recorded by selectively referring to the multiple dependent forms of the previous items in the subsequent items. Also, sometimes, several items are recorded by referring to the multiple dependent forms of other multiple dependent forms of items (a multiple dependent form referring to another multiple dependent form). The items recorded in these multiple dependent forms define multiple technical ideas.

[0127] Technical Thought 1

[0128] A passenger position estimation device estimates the position of a passenger in a vehicle cabin, wherein:

[0129] The above-mentioned passenger position estimation device comprises:

[0130] A transmission control unit (307, 307a) causes radio waves to be transmitted from two or more radars (320, 321, 322, 323, 324, 2a) that receive and send radio waves in the room;

[0131] A receiving strength acquisition unit (308, 308a) for acquiring the receiving strength of the radio waves received by each radar;

[0132] A separation unit (309) for separating the waveform by processing for separating the components of each of the passengers mixed in the waveform, wherein the waveform represents the time variation of the multiple reception intensities of each radar received by the reception intensity acquisition unit;

[0133] A number determination unit (310) determines the number of the passengers in the room based on the waveform separated by the separation unit;

[0134] a distance determination unit (311, 311a) for determining the distance between the passengers and the radars for each of the passengers corresponding to the number of passengers determined by the number determination unit, based on the timing of a change unique to a person occurring in the waveform separated by the separation unit; and

[0135] The passenger position estimation unit (312, 312a) estimates the position of the passenger in the room for each passenger based on the distance between each passenger and each radar determined by the distance determination unit.

[0136] Technical Thought 2

[0137] According to the passenger position estimation device described in technical idea 1,

[0138] The distance determination unit determines the distance between the passengers and each radar for each of the passengers corresponding to the number of passengers determined by the number determination unit, based on the timing of a change in the waveform separated by the separation unit that is estimated to be caused by human breathing.

[0139] Technical Thought 3

[0140] According to the passenger position estimation device described in technical idea 1 or 2,

[0141] The receiving intensity acquisition part separately acquires a reflection characteristic value and a passing characteristic value, wherein the reflection characteristic value is the receiving intensity when the radar in each radar receives the radio wave transmitted from the radar, and the passing characteristic value is the receiving intensity when the radar in each radar receives the radio wave transmitted from other radars other than the radar.

[0142] The separation unit separates the waveform by a process for separating the components of each of the passengers mixed in the waveform, and the waveform represents the time variation of the reflection characteristic values ​​and the passing characteristic values ​​of the multiple radars received by the receiving intensity acquisition unit.

[0143] The number-of-people specifying unit specifies the number of the passengers in the room based on the waveform separated by the separation portion.

[0144] Technical Thought 4

[0145] According to the passenger position estimation device described in any one of technical concepts 1 to 3,

[0146] The transmission control unit causes radio waves to be transmitted from the three or more radars.

[0147] Technical Thought 5

[0148] According to the passenger position estimation device described in technical idea 4,

[0149] At least one of the radars is a portable terminal (2a), which is carried by the passenger and whose position relative to the vehicle is determined by the vehicle system by communicating with three or more antennas arranged in the vehicle. On the other hand, the other radars are radio wave detectors (320a, 321, 324), which are arranged in the vehicle and whose positions relative to the vehicle are predetermined.

[0150] The passenger position estimation unit (312a) sets the distance from the portable terminal determined by the distance determination unit to the distance from the position of the portable terminal relative to the vehicle determined by the system, and on the other hand, sets the distance from the radio wave detector determined by the distance determination unit to the distance from the predetermined position of the radio wave detector relative to the vehicle, and estimates the position of the passenger in the room for each passenger.

[0151] Technical Thought 6

[0152] According to the passenger position estimation device described in technical idea 5,

[0153] A correction unit (313) is provided for correcting the distance from the portable terminal determined by the distance determination unit using the reception intensity of the radio wave corresponding to the point on the waveform used to determine the distance and a predetermined correspondence relationship between the distance in free space and the reception intensity of the radio wave,

[0154] The passenger position estimation unit estimates the position of the passenger in the room for each passenger using the distance corrected by the correction unit with respect to the distance to the mobile terminal determined by the distance determination unit.

Claims

1. A passenger position estimation device for estimating the position of a passenger located in a vehicle interior, wherein: The passenger position estimation device comprises: A transmission control unit (307, 307a) causes radio waves to be transmitted from two or more radars (320, 321, 322, 323, 324, 2a) that receive and send radio waves in the room; A receiving strength acquisition unit (308, 308a) for respectively acquiring the receiving strength of the radio waves received by each radar; A separation unit (309) for separating the waveform by processing for separating the components of each passenger mixed in the waveform, wherein the waveform represents the time variation of the receiving intensity of each radar received by the receiving intensity acquisition unit for a plurality of times; A number determination unit (310) for determining the number of the passengers in the room based on the waveform separated by the separation unit; a distance determination unit (311, 311a) for determining the distance between the passenger and each radar for each of the passengers corresponding to the number of passengers determined by the number determination unit, based on the timing of a change unique to a person occurring in the waveform separated by the separation unit; as well as A passenger position estimation unit (312, 312a) estimates the position of each passenger in the room based on the distance between each passenger and each radar determined by the distance determination unit.

2. The passenger position estimation device according to claim 1, wherein: The distance determination unit determines the distance between the passenger and each radar for each of the passengers corresponding to the number of passengers determined by the number determination unit, based on the timing of a change in the waveform separated by the separation unit that is estimated to be caused by human breathing.

3. The passenger position estimation device according to claim 1, wherein: The receiving intensity acquisition part separately acquires a reflection characteristic value and a passing characteristic value, wherein the reflection characteristic value is the receiving intensity when the radar in each radar receives the radio wave transmitted from the radar, and the passing characteristic value is the receiving intensity when the radar in each radar receives the radio wave transmitted from other radars than the radar. The separation unit separates the waveform by a process for separating the components of each passenger mixed in the waveform, the waveform representing the reflection characteristic values ​​of each radar received by the reception intensity acquisition unit and the time variation of the passing characteristic value for a plurality of times, The number of persons specifying unit specifies the number of the passengers in the room based on the waveform separated by the separation portion.

4. The passenger position estimation device according to any one of claims 1 to 3, wherein: The transmission control unit causes radio waves to be transmitted from three or more of the radars.

5. The passenger position estimation device according to claim 4, wherein: At least one of the radars is a portable terminal (2a) carried by the passenger and whose position relative to the vehicle is determined by the vehicle system by communicating with three or more antennas arranged in the vehicle, and the other of the radars is a radio wave detector (320a, 321, 324) arranged in the vehicle and whose position relative to the vehicle is predetermined. The passenger position estimation unit (312a) sets the distance from the portable terminal determined by the distance determination unit to the distance from the position of the portable terminal relative to the vehicle determined by the system, and on the other hand, sets the distance from the radio wave detector determined by the distance determination unit to the distance from the predetermined position of the radio wave detector relative to the vehicle, and estimates the position of the passenger in the room for each passenger.

6. The passenger position estimation device according to claim 5, wherein: A correction unit (313) is provided for correcting the distance from the portable terminal determined by the distance determination unit by using the reception intensity of the radio wave corresponding to the point on the waveform used to determine the distance and a predetermined correspondence relationship between the distance in free space and the reception intensity of the radio wave, The passenger position estimation unit estimates the position of the passenger in the room for each passenger using the distance corrected by the correction unit with respect to the distance from the mobile terminal determined by the distance determination unit.

7. A passenger position inference method, executed by at least one processor and used to infer the position of a passenger located in a cabin of a vehicle, wherein: The passenger position inference method comprises: a transmission control step of transmitting radio waves from two or more radars (320, 321, 322, 323, 324, 2a) that receive and send radio waves in the room; a receiving strength obtaining step of respectively obtaining the receiving strength of the radio waves received by each radar; a separation step of separating the waveform by a process for separating the components of each of the passengers mixed in the waveform, the waveform representing the time variation of the receiving intensity of each radar received by the receiving intensity acquisition step for a plurality of times; a number determination step of determining the number of the passengers in the room based on the waveform separated by the separation step; a distance determining step of determining the distance between the passengers and each radar for each of the passengers corresponding to the number of passengers determined in the number determining step, based on the timing of a change unique to a person occurring in the waveform separated in the separating step; and The passenger position estimating step estimates the position of the passenger in the room for each passenger based on the distance between each passenger and each radar determined in the distance determining step.

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