Electronic device, method for controlling electronic device, and program

Abstract

To provide an electronic device, a control method for the electronic device, and a program that can detect an existence and an existence position of a human or the like with high accuracy by transmitting and receiving radio waves in at least a partially closed space.SOLUTION: An electronic device includes a signal processing unit that generates information about the speed of a first detection target from a reflected wave which is a reflected transmitted wave, and generates information about a position of the first detection target based on the information about the speed of the first detection target and pre-acquired specified information about the speed of a second detection target corresponding to the existence position of the second detection target.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This disclosure relates to electronic equipment, methods for controlling electronic equipment, and programs. [Background technology]

[0002] For example, in fields such as the automotive industry, technologies for measuring the distance between a vehicle and a designated object are considered important. In particular, in recent years, various radar (RADAR (Radio Detecting and Ranging)) technologies have been researched, which measure the distance to an object by transmitting radio waves such as millimeter waves and receiving reflected waves that are reflected from obstacles and other objects. The importance of such distance measurement technologies is expected to increase even further in the future with the development of technologies that assist drivers and technologies related to autonomous driving that automate part or all of the driving process.

[0003] Furthermore, various technologies have been proposed for detecting the presence of an object by receiving reflected waves that have been reflected by a predetermined object. For example, Patent Document 1 proposes a technology for detecting the number and location of occupants in a vehicle using a radar unit installed inside the vehicle. Patent Document 1 discloses a technology for detecting the state of occupants in a vehicle using a transceiver positioned closest to the driver's seat among the seats in the vehicle. Also, for example, Patent Document 2 proposes a technology for detecting living organisms inside a vehicle by irradiating the vehicle with millimeter waves from outside the vehicle. Patent Document 2 discloses that the presence or absence of living organisms inside the vehicle is determined by irradiating millimeter waves into the vehicle from the front of the vehicle through the windshield and receiving the reflected wave data. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-181225 [Patent Document 2] Japanese Patent Publication No. 2022-039539 [Overview of the project] [Problems that the invention aims to solve]

[0005] For example, if the presence and location of occupants, including the driver, can be detected with good accuracy in at least partially enclosed spaces such as the interior of a car, by transmitting and receiving radio waves such as millimeter waves, it is expected to be useful in a wide variety of fields.

[0006] The purpose of this disclosure is to provide electronic equipment, a control method for electronic equipment, and a program that can detect the presence and location of humans or other objects with good accuracy by transmitting and receiving radio waves in at least a partially enclosed space. [Means for solving the problem]

[0008] An electronic device according to one embodiment is The system includes a signal processing unit that detects an object based on a transmitted signal that is transmitted as a transmitted wave and a received signal that is received as a reflected wave when the transmitted wave is reflected off the object. The signal processing unit, A spectrogram R is calculated that shows the intensity of the reflected wave corresponding to a predetermined distance at a predetermined time. The base F0 is the time-averaged base of the spectrogram R when the aforementioned object is not present in the predetermined region. The object at a predetermined position X in the predetermined region i The basis F is the time-averaged basis of the spectrogram R when it exists in (i is an integer greater than or equal to 1). i year, The spectrogram R, and the basis F0 and the basis F i Based on the teacher matrix F generated from and the activation matrix G, the activation matrix G is calculated using a distance function such that the value of Y = R - FG is minimized.

[0009] A control method for electronic equipment according to one embodiment is: Detecting the target based on a transmission signal transmitted as a transmission wave and a reception signal received as a reflected wave obtained by reflecting the transmission wave from the target; Calculating a spectrogram R indicating the intensity corresponding to a predetermined distance at a predetermined time of the reflected wave; When the target does not exist in a predetermined region, the base obtained by time-averaging the spectrogram R is defined as base F0, and when the target exists at a predetermined position X i (i is an integer of 1 or more) in the predetermined region, the base obtained by time-averaging the spectrogram R is defined as base F i Calculating the activation matrix G such that the value of Y = R - FG is minimized by using a distance function based on the spectrogram R, the base F0, the base F [[ID=…]] i and the teacher matrix F and the activation matrix G generated therefrom; including.

[0010] A program according to an embodiment causes an electronic device to Detect the target based on a transmission signal transmitted as a transmission wave and a reception signal received as a reflected wave obtained by reflecting the transmission wave from the target; Calculate a spectrogram R indicating the intensity corresponding to a predetermined distance at a predetermined time of the reflected wave; When the target does not exist in a predetermined region, the base obtained by time-averaging the spectrogram R is defined as base F0, and when the target exists at a predetermined position X i (i is an integer of 1 or more) in the predetermined region, the base obtained by time-averaging the spectrogram R is defined as base F i Calculate the activation matrix G such that the value of Y = R - FG is minimized by using a distance function based on the spectrogram R, the base F0, the base F i and the teacher matrix F and the activation matrix G generated therefrom; and execute.

Advantages of the Invention

[0011] It should be noted that the text contains some tags like i , i , etc. which are likely part of a specific technical or patent-related format and are left unchanged as per the requirement. Also, in the original text, there seems to be an incomplete reference in some lines like "前記対象が前記所定の領域における所定位置X i (iは1以上の整数)に存在している場合の……" where the full meaning might be clearer with more context. The translation attempts to be as literal as possible while maintaining the integrity of the text structure and the tags. According to one embodiment, in at least a partially closed space, an electronic device, a method for controlling an electronic device, and a program capable of detecting the presence and position of a human or the like with good accuracy by transmitting and receiving radio waves can be provided.

Brief Description of Drawings

[0012] [Figure 1] It is a diagram for explaining a usage mode of an electronic device according to one embodiment. [Figure 2] It is a functional block diagram schematically showing the configuration of an electronic device according to one embodiment. [Figure 3] It is a diagram for explaining the configuration of a signal processed by an electronic device according to one embodiment. [Figure 4] It is a diagram for explaining signal processing by an electronic device according to one embodiment. [Figure 5] It is a diagram for explaining signal processing by an electronic device according to one embodiment. [Figure 6] It is a diagram for explaining signal processing by an electronic device according to one embodiment. [Figure 7] It is a diagram schematically showing an example of the arrangement of antennas in an antenna array of an electronic device according to one embodiment and the operating principle. [Figure 8] It is a diagram showing an example of the arrangement of antennas in an antenna array of an electronic device according to one embodiment. [Figure 9] It is a diagram showing an example of a state where an electronic device according to one embodiment is installed in an automobile. [Figure 10] It is a diagram showing an example of the position where an electronic device according to one embodiment is installed in an automobile and the position of a seat arranged in the automobile. [Figure 11] It is a diagram showing an example of a result of detecting a passenger by a radar sensor in the passenger compartment of an automobile. [Figure 12] It is a flowchart for explaining the operation of an electronic device according to one embodiment. [Figure 13] It is a diagram showing an example of a spectrogram generated in an electronic device according to one embodiment. [Figure 14] This is a flowchart illustrating the operation of an electronic device according to one embodiment. [Figure 15] This figure illustrates the dimensions of a matrix processed by an electronic device according to one embodiment. [Figure 16] This figure shows an example of the components of an activation matrix G generated by an electronic device according to one embodiment. [Modes for carrying out the invention]

[0013] One embodiment will be described in detail below with reference to the drawings.

[0014] In this disclosure, “electronic device” may mean an electrical device. “User” may mean a person (typically a human) or animal using the system and / or electronic device according to one embodiment. A user may also include a person who uses the electronic device according to one embodiment to monitor or observe a subject, such as a human. “Subject” may mean a person (e.g., a human or animal) who is monitored by the electronic device according to one embodiment. Furthermore, a user may include a subject.

[0015] An electronic device according to one embodiment can detect the presence and location of, for example, passengers including the driver, in at least a partially enclosed space such as the interior of a car in which the electronic device is installed. Therefore, the electronic device according to one embodiment may be used in a moving body such as the interior of a car in which the electronic device is installed. Here, the moving body in which the electronic device according to one embodiment can be installed is not limited to cars. For example, the electronic device according to one embodiment may be installed in various moving bodies such as autonomous vehicles, buses, trucks, taxis, ships, aircraft, helicopters, spacecraft, rockets, agricultural equipment such as tractors, snowplows, street sweepers, police cars, and ambulances. Furthermore, the moving bodies such as cars included in this disclosure are not limited by length, width, height, engine displacement, passenger capacity, or load capacity. For example, the cars in this disclosure include cars with an engine displacement greater than 660cc and cars with an engine displacement of 660cc or less, so-called kei cars. Furthermore, the cars included in this disclosure also include cars that use electricity for part or all of their energy and use motors.

[0016] Furthermore, the electronic device according to one embodiment may not be limited to being used inside a mobile vehicle. For example, the electronic device according to one embodiment may be installed indoors, such as in a room. For example, the electronic device according to one embodiment may be installed in an office, a conference room, a storage room, a hospital room, a toilet, a bathroom, a sauna, a movie theater, a theater, a stadium, a concert hall, an office, a restaurant, a cafe, a shop, a factory, etc. Also, the electronic device according to one embodiment may not only be used in places where humans are present, but also in places where animals other than humans are present. For example, the electronic device according to one embodiment may be installed in a cage where pets are kept, in a barn where livestock are kept, or in a container used when transporting animals.

[0017] An electronic device according to one embodiment may be installed on any moving object or on any stationary object. The electronic device according to one embodiment can transmit a wave to the surrounding area from a transmitting antenna. The transmitting antenna may consist of multiple antennas. The electronic device according to one embodiment can also receive reflected waves from a receiving antenna. The receiving antenna may consist of multiple antennas. At least one of the transmitting antenna and the receiving antenna may be provided on the electronic device or, for example, on a radar sensor.

[0018] An electronic device according to one embodiment will be described in detail below with reference to the drawings. First, an example of object detection by the electronic device according to one embodiment will be described.

[0019] Figure 1 illustrates an example of how an electronic device according to one embodiment is used. Figure 1 shows an example of an electronic device that has the function of a sensor equipped with a transmitting antenna and a receiving antenna according to one embodiment. The electronic device according to one embodiment may include, for example, a function based on FMCW radar (Frequency Modulated Continuous Wave radar) technology.

[0020] An electronic device 1 according to one embodiment may include a transmitting unit and a receiving unit, which will be described later. As described later, the transmitting unit may include a transmitting antenna array 24. The receiving unit may also include a receiving antenna array 31. The specific configurations of the electronic device 1, the transmitting unit, and the receiving unit will be described later. For ease of viewing, Figure 1 schematically shows the electronic device 1 equipped with a transmitting antenna array 24 and a receiving antenna array 31. The electronic device 1 may also appropriately include at least one of other functional units, such as at least a part of the signal processing unit 10 (see Figure 2) included in the electronic device 1. Furthermore, the electronic device 1 may have at least one of other functional units, such as at least a part of the signal processing unit 10 (see Figure 2) included in the electronic device 1, located outside the electronic device 1. In Figure 1, the electronic device 1 may be moving, or it may be stationary.

[0021] In the example shown in Figure 1, the electronic device 1 is shown in a simplified form, comprising a transmitting unit with a transmitting antenna array 24 and a receiving unit with a receiving antenna array 31. The electronic device 1 may, for example, comprise multiple transmitting units and / or multiple receiving units. The transmitting unit may comprise a transmitting antenna array 24 composed of multiple transmitting antennas. The receiving unit may comprise a receiving antenna array 31 composed of multiple receiving antennas. Here, the location in which the transmitting unit and / or receiving unit are installed in the electronic device 1 is not limited to the location shown in Figure 1, but may be in other locations as appropriate. Furthermore, the number of transmitting units and / or receiving units may be one or more arbitrary numbers depending on various conditions (or requirements) such as the heart rate detection range and / or detection accuracy by the electronic device 1.

[0022] As described later, the electronic device 1 transmits electromagnetic waves as transmitted waves from the transmitting antenna array 24. For example, if a predetermined object (for example, the object 200 shown in Figure 1) is present around the electronic device 1, at least a portion of the transmitted waves transmitted from the electronic device 1 will be reflected by the object and become reflected waves. By receiving such reflected waves with, for example, the receiving antenna array 31 of the electronic device 1, the electronic device 1 can detect the object as a target.

[0023] The electronic device 1, equipped with a transmitting antenna array 24, may typically be a radar (RADAR (Radio Detecting and Ranging)) sensor that transmits and receives radio waves. However, the electronic device 1 is not limited to a radar sensor. In one embodiment, the electronic device 1 may be a sensor based on, for example, light wave-based LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) technology. Such sensors may be configured to include, for example, a patch antenna. Since technologies such as RADAR and LIDAR are already known, detailed explanations may be simplified or omitted as appropriate. Furthermore, in one embodiment, the electronic device 1 may be a sensor based on, for example, a technology that detects objects by transmitting and receiving sound waves or ultrasound.

[0024] The electronic device 1 shown in Figure 1 receives the reflected wave of the transmitted wave from the transmitting antenna array 24 from the receiving antenna array 31. In this way, the electronic device 1 can detect a predetermined object 200 located within a predetermined distance from the electronic device 1 as a target. For example, as shown in Figure 1, the electronic device 1 can measure the distance L between the electronic device 1 and the predetermined object 200. The electronic device 1 can also measure the relative velocity between the electronic device 1 and the predetermined object 200. Furthermore, the electronic device 1 can measure (estimate) the direction in which the reflected wave from the predetermined object 200 arrives at the electronic device 1, i.e., the direction of arrival (angle of arrival θ).

[0025] In Figure 1, the XY plane may be, for example, a plane approximately parallel to the Earth's surface. In this case, the positive direction of the Z axis shown in Figure 1 may be considered to be vertically upward. In Figure 1, the electronic device 1 may be positioned on a plane parallel to the XY plane. Also, in Figure 1, the object 200 may be, for example, located on the Earth's surface approximately parallel to the XY plane.

[0026] Here, "Subject 200" may refer to, for example, a person present around the electronic device 1. Alternatively, "Subject 200" may refer to a living being other than a human, such as an animal present around the electronic device 1. As mentioned above, "Subject 200" may be moving, stationary, or still. In this disclosure, objects detected by the electronic device 1 include not only inanimate objects but also living beings such as people, dogs, cats, horses, and other animals. Objects detected by the electronic device 1 in this disclosure may also include targets, such as people, objects, and animals, detected by radar technology. In this disclosure, "target" may refer to people, objects, and animals. Hereafter, we will assume that objects such as "Subject 200" present around the electronic device 1 are humans (or animals). Hereafter, "Subject 200" will also be referred to as "Passenger 200" as appropriate. A passenger 200 may be, for example, a person in a moving vehicle such as a car on which the electronic device 1 is installed. Also, in this disclosure, "target" may refer to the above-mentioned "Subject 200".

[0027] In Figure 1, the ratio of the size of the electronic device 1 to the size of the object 200 does not necessarily represent the actual ratio. Also, in Figure 1, the transmitting antenna array 24 of the transmitting unit and the receiving antenna array 31 of the receiving unit are shown installed outside the electronic device 1. However, in one embodiment, the transmitting antenna array 24 of the transmitting unit and / or the receiving antenna array 31 of the receiving unit may be installed at various positions on the electronic device 1. For example, in one embodiment, the transmitting antenna array 24 of the transmitting unit and / or the receiving antenna array 31 of the receiving unit may be installed inside the electronic device 1 so that they are not visible from the outside of the electronic device 1.

[0028] In the following explanation, we will assume that the transmitting antenna of electronic device 1 transmits radio waves in a frequency band such as millimeter waves (30 GHz or higher) or quasi-millimeter waves (e.g., around 20 GHz to 30 GHz). On the other hand, the transmitting antenna of electronic device 1 may also transmit radio waves with a frequency bandwidth of 4 GHz, such as 77 GHz to 81 GHz.

[0029] Figure 2 is a functional block diagram schematically showing an example of the configuration of the electronic device 1 according to one embodiment. An example of the configuration of the electronic device 1 according to one embodiment will be described below.

[0030] When measuring distance and other parameters using millimeter-wave radar, frequency-modulated continuous wave radar (FMCW radar) is often used. FMCW radar generates its transmission signal by sweeping the frequency of the transmitted radio waves. Therefore, in a millimeter-wave FMCW radar using, for example, the 79 GHz frequency band, the radio wave frequencies used will have a frequency bandwidth of 4 GHz, such as 77 GHz to 81 GHz. Radar in the 79 GHz frequency band has the advantage of a wider usable frequency bandwidth than other millimeter-wave / sub-millimeter-wave radars, such as those in the 24 GHz, 60 GHz, and 76 GHz frequency bands. The following describes such an embodiment as an example.

[0031] The radar scheme of the FMCW radar used in this disclosure may include the Fast-Chirp Modulation (FCM) scheme, which transmits chirp signals at a shorter period than usual. The signals generated by the electronic device 1 are not limited to FMCW signals. The signals generated by the electronic device 1 may be signals of various schemes other than FMCW. The transmitted signal sequence stored in any memory unit may differ depending on these various schemes. For example, in the case of the FMCW radar signal described above, signals whose frequency increases and decreases with each time sample may be used. Since known techniques can be appropriately applied to the various schemes described above, a more detailed explanation is omitted.

[0032] As shown in Figure 2, the electronic device 1 according to one embodiment includes a signal processing unit 10. The signal processing unit 10 may include a signal generation processing unit 11 and a received signal processing unit 12. The signal generation processing unit 11 and the received signal processing unit 12 will be described further later.

[0033] Furthermore, the electronic device 1 according to one embodiment includes a transmitting DAC 21, a transmitting circuit 22, a millimeter-wave transmitting circuit 23, and a transmitting antenna array 24 as a transmitting unit. Furthermore, the electronic device 1 according to one embodiment includes a receiving antenna array 31, a mixer 32, a receiving circuit 33, and a receiving ADC 34 as a receiving unit. The electronic device 1 according to one embodiment does not have to include at least one of the functional units shown in Figure 2, and may include functional units other than those shown in Figure 2. The electronic device 1 shown in Figure 2 may be configured using a circuit that is basically the same as that of a general radar using electromagnetic waves such as millimeter waves. On the other hand, in the electronic device 1 according to one embodiment, the signal processing by the signal processing unit 10 may include processing that differs from that of a conventional general radar.

[0034] The signal processing unit 10 provided in the electronic device 1 according to one embodiment can control the operation of the entire electronic device 1, including the control of each functional unit constituting the electronic device 1. In particular, the signal processing unit 10 performs various processing on the signals handled by the electronic device 1. The signal processing unit 10 may include at least one processor, such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), in order to provide control and processing capabilities for executing various functions. The signal processing unit 10 may be implemented as a single processor, as several processors, or as separate processors. The processor may be implemented as a single integrated circuit. An integrated circuit is also called an IC (Integrated Circuit). The processor may be implemented as a plurality of communicably connected integrated circuits and discrete circuits. The processor may be implemented based on various other known technologies. In one embodiment, the signal processing unit 10 may be configured as, for example, a CPU (hardware) and a program (software) executed by the CPU. The signal processing unit 10 may appropriately include a storage unit (memory) necessary for the operation of the signal processing unit 10.

[0035] The signal generation processing unit 11 of the signal processing unit 10 generates a signal to be transmitted from the electronic device 1. In the electronic device 1 according to one embodiment, the signal generation processing unit 11 may generate a transmission signal (transmission chirp signal), such as a chirp signal. In particular, the signal generation processing unit 11 may generate a signal whose frequency changes periodically linearly (linear chirp signal). For example, the signal generation processing unit 11 may generate a chirp signal whose frequency increases periodically linearly from 77 GHz to 81 GHz as time progresses. Alternatively, for example, the signal generation processing unit 11 may generate a signal whose frequency periodically repeats a linear increase (up chirp) and decrease (down chirp) from 77 GHz to 81 GHz as time progresses. The signal generated by the signal generation processing unit 11 may be pre-set in, for example, the signal processing unit 10. Alternatively, the signal generated by the signal generation processing unit 11 may be pre-stored in, for example, any memory unit in the signal processing unit 10. Since chirp signals used in technical fields such as radar are known, a more detailed explanation will be simplified or omitted as appropriate. The signal generated by the signal generation processing unit 11 is supplied to the transmitting DAC 21. For this reason, the signal generation processing unit 11 may be connected to the transmitting DAC 21.

[0036] The transmitting DAC (digital-to-analog converter) 21 has the function of converting the digital signal supplied from the signal generation processing unit 11 into an analog signal. The transmitting DAC 21 may be configured to include a general-purpose digital-to-analog converter. The signal converted to analog by the transmitting DAC 21 is supplied to the transmitting circuit 22. For this reason, the transmitting DAC 21 may be connected to the transmitting circuit 22.

[0037] The transmitting circuit 22 has the function of converting the signal, which has been converted to analog by the transmitting DAC 21, into an intermediate frequency (IF) band. The transmitting circuit 22 may be configured to include a transmitting circuit for a general IF band. The signal processed by the transmitting circuit 22 is supplied to the millimeter-wave transmitting circuit 23. For this reason, the transmitting circuit 22 may be connected to the millimeter-wave transmitting circuit 23.

[0038] The millimeter-wave transmitting circuit 23 has the function of transmitting the signal processed by the transmitting circuit 22 as a millimeter wave (RF wave). The millimeter-wave transmitting circuit 23 may be configured to include a general millimeter-wave transmitting circuit. The signal processed by the millimeter-wave transmitting circuit 23 is supplied to the transmitting antenna array 24. For this reason, the millimeter-wave transmitting circuit 23 may be connected to the transmitting antenna array 24. In addition, the signal processed by the millimeter-wave transmitting circuit 23 is also supplied to the mixer 32. For this reason, the millimeter-wave transmitting circuit 23 may also be connected to the mixer 32.

[0039] The transmitting antenna array 24 is an array of multiple transmitting antennas. Figure 2 shows a simplified configuration of the transmitting antenna array 24. The transmitting antenna array 24 transmits the signal processed by the millimeter-wave transmitting circuit 23 to the outside of the electronic device 1. The transmitting antenna array 24 may include a transmitting antenna array used in a typical millimeter-wave radar.

[0040] In this way, the electronic device 1 according to one embodiment is equipped with a transmitting antenna (transmitting antenna array 24) and can transmit a transmission signal (for example, a transmitting chirp signal) as a transmission wave from the transmitting antenna array 24.

[0041] For example, consider the case where an object such as a passenger 200 (e.g., a person) is present around the electronic device 1, as shown in Figure 2. In this case, at least a portion of the transmitted waves sent from the transmitting antenna array 24 will be reflected by the object such as the passenger 200. At least a portion of the transmitted waves sent from the transmitting antenna array 24 that are reflected by the object such as the passenger 200 may be reflected towards the receiving antenna array 31.

[0042] The receiving antenna array 31 receives reflected waves. Here, these reflected waves may be at least a portion of the transmitted waves sent from the transmitting antenna array 24 that have been reflected by an object such as a passenger 200.

[0043] The receiving antenna array 31 is an array of multiple receiving antennas. Figure 2 shows a simplified configuration of the receiving antenna array 31. The receiving antenna array 31 receives the reflected wave that is transmitted from the transmitting antenna array 24. The receiving antenna array 31 may include a receiving antenna array used in a typical millimeter-wave radar. The receiving antenna array 31 supplies the received signal, which is received as a reflected wave, to the mixer 32. For this reason, the receiving antenna array 31 may be connected to the mixer 32.

[0044] Mixer 32 converts the signal processed by the millimeter-wave transmitting circuit 23 (transmitted signal) and the received signal received by the receiving antenna array 31 into an intermediate frequency (IF) bandwidth. Mixer 32 may include a mixer commonly used in millimeter-wave radar. Mixer 32 supplies the resulting combined signal to the receiving circuit 33. For this reason, mixer 32 may be connected to the receiving circuit 33.

[0045] The receiving circuit 33 has the function of analog processing the signal converted to the IF band by the mixer 32. The receiving circuit 33 may be configured to include a receiving circuit that converts to a general IF band. The signal processed by the receiving circuit 33 is supplied to the receiving ADC 34. For this reason, the receiving circuit 33 may be connected to the receiving ADC 34.

[0046] The receiving ADC (analog-to-digital converter) 34 has the function of converting the analog signal supplied from the receiving circuit 33 into a digital signal. The receiving ADC 34 may be configured to include a general analog-to-digital converter. The signal digitized by the receiving ADC 34 is supplied to the receiving signal processing unit 12 of the signal processing unit 10. For this reason, the receiving ADC 34 may be connected to the signal processing unit 10.

[0047] The received signal processing unit 12 of the signal processing unit 10 has the function of performing various processes on the digital signal supplied from the receiving ADC 34. For example, the received signal processing unit 12 calculates the distance from the electronic device 1 to an object such as a passenger 200 based on the digital signal supplied from the receiving ADC 34 (distance measurement). The received signal processing unit 12 also calculates the relative velocity of an object such as a passenger 200 with respect to the electronic device 1 based on the digital signal supplied from the receiving ADC 34 (velocity measurement). Furthermore, the received signal processing unit 12 calculates the azimuth angle of an object such as a passenger 200 as seen from the electronic device 1 based on the digital signal supplied from the receiving ADC 34 (angle measurement or arrival angle estimation). Specifically, I / Q converted data may be input to the received signal processing unit 12. Upon input of such data, the received signal processing unit 12 performs two-dimensional fast fourier transform (2D-FFT) processing in the distance (range) direction and the velocity (velocity) direction, respectively. Subsequently, the received signal processing unit 12 performs processing such as CFAR (Constant False Alarm Rate) to suppress false alarms by removing noise points and to maintain a constant probability. Then, the received signal processing unit 12 obtains the position of an object such as a passenger 200 by estimating the arrival angle for points that satisfy the CFAR criteria. In one embodiment, the received signal processing unit 12 does not necessarily have to perform CFAR processing when estimating the arrival angle. The information generated as a result of distance measurement, speed measurement, and angle measurement (arrival angle estimation) by the received signal processing unit 12 may be supplied to the communication interface 50. In addition, various information output as a result of processing by the received signal processing unit 12 may also be supplied to the communication interface 50. For this reason, the signal processing unit 10 may be connected to the communication interface 50. Various information calculated and / or processed by the signal processing unit 10 may be supplied to other functional units other than the communication interface 50.

[0048] The communication interface 50 is configured to include an interface that outputs information supplied from the signal processing unit 10 to, for example, an external device 60. The communication interface 50 may output information such as the position, velocity, and angle of an object such as a passenger 200 as a signal such as CAN (Controller Area Network) to the external device 60. For example, information such as the position, velocity, and angle of an object such as a passenger 200 may be supplied to the external device 60 via the communication interface 50. For this reason, the communication interface 50 may be connected to the external device 60. In one embodiment, various types of information calculated and / or processed by the signal processing unit 10 may be supplied to, for example, an external device 60 via the communication interface 50.

[0049] As shown in Figure 2, in one embodiment, the electronic device 1 may be connected to an external device 60 by wire or wirelessly via a communication interface 50. In one embodiment, the external device 60 may include any computer and / or any control device. Furthermore, the electronic device 1 in one embodiment may be configured to include the external device 60. The external device 60 may include a display unit, such as a display, that displays any image and / or video. The external device 60 may also include an audio output unit, such as a speaker, that outputs any sound and / or voice. The external device 60 may also include a tactile presentation unit that presents a predetermined tactile sensation, such as vibration or click, to the user of the electronic device 1. With this configuration, the external device 60 can transmit the processing results from the signal processing unit 10 to the user of the electronic device 1, for example, as visual information, auditory information, and / or tactile information.

[0050] Figure 3 illustrates an example of a chirp signal generated by the signal generation processing unit 11 of the signal processing unit 10.

[0051] Figure 3 shows the temporal structure of one frame when using the FCM (Fast-Chirp Modulation) method. Figure 3 shows an example of a received signal using the FCM method. FCM is a method that repeats chirp signals, shown as c1, c2, c3, c4, ..., cn in Figure 3, at short intervals (for example, longer than the round-trip time between the radar and the target of electromagnetic waves calculated from the maximum measuring distance). In FCM, for the convenience of signal processing of the received signal, it is often performed by dividing it into subframe units as shown in Figure 3.

[0052] In Figure 3, the horizontal axis represents elapsed time, and the vertical axis represents frequency. In the example shown in Figure 3, the signal generation processing unit 11 generates a linear chirp signal whose frequency changes linearly and periodically. In Figure 3, each chirp signal is shown as c1, c2, c3, c4, ..., cn. As shown in Figure 3, the frequency of each chirp signal increases linearly with the passage of time.

[0053] In the example shown in Figure 3, several chirp signals, such as c1, c2, c3, c4, ..., cn, are included to form one subframe. That is, subframe 1 and subframe 2, etc., shown in Figure 3, are each composed of several chirp signals, such as c1, c2, c3, c4, ..., cn. Also, in the example shown in Figure 3, several subframes, such as subframe 1, subframe 2, ..., subframe N, are included to form one frame (1 frame). That is, 1 frame shown in Figure 3 is composed of N subframes. Furthermore, 1 frame shown in Figure 3 may be designated as frame 1, followed by frame 2, frame 3, ..., etc. Each of these frames may be composed of N subframes, similar to frame 1. In addition, a frame interval of a predetermined length may be included between frames. One frame shown in Figure 3 may be, for example, about 30 to 50 milliseconds long.

[0054] In one embodiment of the electronic device 1, the signal generation processing unit 11 may generate the transmission signal as any number of frames. Also, in Figure 3, some chirp signals are omitted. Thus, the relationship between the time and frequency of the transmission signal generated by the signal generation processing unit 11 may be stored, for example, in the memory unit of the signal processing unit 10.

[0055] Thus, the electronic device 1 according to one embodiment may transmit a transmission signal consisting of subframes containing multiple chirp signals. Alternatively, the electronic device 1 according to one embodiment may transmit a transmission signal consisting of frames containing a predetermined number of subframes.

[0056] Hereinafter, the electronic device 1 will be described as transmitting a transmission signal with a frame structure as shown in Figure 3. However, the frame structure shown in Figure 3 is just one example, and the number of chirp signals included in a single subframe may be arbitrary. That is, in one embodiment, the signal generation processing unit 11 may generate subframes containing any number (e.g., any multiple) chirp signals. Also, the subframe structure shown in Figure 3 is just one example, and the number of subframes included in a single frame may be arbitrary. That is, in one embodiment, the signal generation processing unit 11 may generate a frame containing any number (e.g., any multiple) subframes. The signal generation processing unit 11 may generate signals of different frequencies. The signal generation processing unit 11 may generate multiple discrete signals with different bandwidths and frequencies f.

[0057] Figure 4 shows a portion of the subframe shown in Figure 3 in a different configuration. Figure 4 shows individual samples of the received signal after receiving the transmitted signal shown in Figure 3, as a result of performing a 2D-FFT, which is a process performed in the received signal processing unit 12 (Figure 2) of the signal processing unit 10.

[0058] As shown in Figure 4, each subframe, such as subframe 1, ..., subframe N, stores each chirp signal c1, c2, c3, c4, ..., cn. In Figure 4, each chirp signal c1, c2, c3, c4, ..., cn is composed of samples represented by horizontally arranged grids. The received signals shown in Figure 4 are subjected to 2D-FFT, CFAR, and / or integrated signal processing of each subframe by the received signal processing unit 12 shown in Figure 2.

[0059] Figure 5 shows an example in which a point cloud on the range-Doppler (distance-velocity) plane is calculated as a result of 2D-FFT, CFAR, and integrated signal processing of each subframe performed in the received signal processing unit 12 shown in Figure 2.

[0060] In Figure 5, the horizontal direction represents range (distance), and the vertical direction represents velocity. In Figure 5, the filled square s1 represents a point cloud indicating signals that exceeded the CFAR threshold. In Figure 5, the unfilled square s2 represents a bin (2D-FFT sample) with no point cloud, where the CFAR threshold was not exceeded. The point cloud on the range-Doppler plane calculated in Figure 5 has its bearing from the radar calculated by direction estimation, and its position and velocity on the 2D plane are calculated as a point cloud representing an object such as occupant 200. Here, direction estimation may be calculated by beamformer and / or subspace method. Representative subspace method algorithms include MUSIC (Multiple Signal Classification) and ESPRIT (Estimation of Signal Parameters via Rotation Invariance Technique).

[0061] Figure 6 shows an example of the result of the receiving signal processing unit 12 performing direction estimation and then converting the point cloud coordinates from the range-Doppler plane shown in Figure 5 to the XY plane. As shown in Figure 6, the receiving signal processing unit 12 can plot the point cloud PG on the XY plane. Here, the point cloud PG is composed of points P (coordinates (x,y)). Each point P also has an angle θ and a radial velocity Vr in polar coordinates.

[0062] The received signal processing unit 12 detects objects within the range to which the transmitted wave T was transmitted, based on at least one of the results of 2D-FFT and angle estimation. The received signal processing unit 12 may also perform object detection by, for example, clustering processing based on the estimated distance information, velocity information, and angle information, respectively. An algorithm known for clustering data is DBSCAN (Density-based spatial clustering of applications with noise). This is an algorithm that performs density-based clustering. In the clustering process, for example, the average power of the points constituting the detected object may be calculated. The distance information, velocity information, angle information, and power information of the object detected by the received signal processing unit 12 may be supplied to an external device 60, for example, via the communication interface 50.

[0063] As described above, the electronic device 1 may include a transmitting antenna (transmitting antenna array 24), a receiving antenna (receiving antenna array 31), and a signal processing unit 10. The transmitting antenna array 24 transmits a transmission wave T. The receiving antenna array 31 receives a reflected wave R, which is the transmission wave T reflected off an object. The signal processing unit 10 then detects an object (such as a passenger 200) that reflects the transmission wave T, based on the transmission signal transmitted as the transmission wave T and the received signal received as the reflected wave R. Thus, the electronic device 1 includes a signal processing unit 10 that detects an object (such as a passenger) based on the transmission signal transmitted as the transmission wave and the received signal received as the reflected wave that the transmission wave has reflected off an object.

[0064] Next, we will further explain the estimation of the direction of the arriving wave (arrival angle estimation) using the antenna array of the electronic device 1 according to one embodiment.

[0065] Figure 7 illustrates the configuration of the receiving antenna array 31 of the electronic device 1 according to one embodiment, and the principle of direction estimation of the incoming wave by the receiving antenna array 31. Figure 7 shows an example of radio wave reception by the receiving antenna array 31.

[0066] As shown in Figure 7, the receiving antenna array 31 may be an array of sensors such as receiving antennas arranged in a straight line. As shown in Figure 7, in one embodiment, the receiving antenna array 31 may be configured to include a plurality of receiving antennas arranged in a straight line. In Figure 7, the receiving antenna array 31 is antenna x1, x2, x3, ..., x MMultiple antennas, such as those shown, are indicated by small circles. Figure 7 conceptually shows the arrangement of multiple antennas constituting the receiving antenna array 31. The actual shapes of the multiple antennas constituting the receiving antenna array 31 may be different from the small circles, for example, patch antennas. The receiving antenna array 31 may be composed of any number of antennas. Also, as shown in Figure 7, the multiple antennas constituting the receiving antenna array 31 are arranged at intervals of the array pitch d. A sensor array in which sensors corresponding to various physical waves (antennas, ultrasonic transducers, microphones, etc.) are arranged in an array is also called a Uniform Linear Array (ULA). As shown in Figure 7, physical waves (electromagnetic waves and sound waves, etc.) arrive from various directions, such as θ1 and θ2. Here, θ1 and θ2 may be the (estimated) angles of arrival described above. In this way, a sensor array such as the receiving antenna array 31 can estimate the direction of arrival (angle of arrival) by utilizing the phase difference that occurs in the measured values ​​between sensors according to the direction of arrival of the physical wave. Thus, the method for estimating the direction of arrival of a wave is also referred to as arrival angle estimation, arrival angle estimation, or direction of arrival estimation (DoA).

[0067] In one embodiment of the electronic device 1, at least one of the transmitting antenna array 24 and the receiving antenna array 31 may be configured with multiple antennas arranged in a straight line. This allows for appropriately narrowing the directivity during transmission and reception of radio waves, for example, in millimeter-wave radar. When transmitting a wave, the direction of the transmitting beam is often controlled by a beamformer. On the other hand, when receiving a reflected wave, the direction of arrival of the reflected wave is often estimated by a subspace method (such as MUSIC and ESPRIT mentioned above) rather than a beamformer. In beamformers and subspace methods, in a ULA as shown in Figure 7, a phase difference occurs in the measured values ​​between sensors depending on the direction of arrival of electromagnetic waves arriving from various directions. Therefore, the direction of arrival of the reflected wave can be estimated by utilizing this phase difference.

[0068] Next, we will further explain the estimation of the angles of the incoming wave in two directions using the antenna array of the electronic device 1 according to one embodiment.

[0069] Figure 8 shows an example of an antenna arrangement for estimating the direction of arrival of two orthogonal angles.

[0070] As shown in Figure 8, in one embodiment of the electronic device 1, the transmitting antenna array 24 and / or receiving antenna array 31 may be configured to include an array of multiple patch antenna units.

[0071] In the transmitting antenna array 24 shown in Figure 8, one patch antenna unit may consist of multiple elements electrically connected in the direction 1 shown in the figure. In each patch antenna unit, the multiple elements may be electrically connected by wiring such as striplines on a substrate. In each patch antenna unit, each of the multiple elements is spaced at intervals d shorter than half the wavelength λ of the transmitted wave. 1,t They may be spaced apart by only a certain amount. In Figure 8, each patch antenna unit may consist of two or any number of elements electrically connected.

[0072] Furthermore, as shown in Figure 8, the transmitting antenna array 24 may be arranged as a plurality of patch antenna units arranged in the direction 2 shown in the figure. Each patch antenna unit is spaced at intervals d shorter than half the wavelength λ of the transmitted wave. 2,t They may be spaced apart by only a certain amount. In one embodiment, the transmitting antenna array 24 may include two or any number of patch antenna units.

[0073] As shown in Figure 8, in one embodiment, the receiving antenna array 31 may be a modified arrangement of the elements in the transmitting antenna array 24. That is, in the receiving antenna array 31 shown in Figure 8, one patch antenna unit may be composed of multiple elements electrically connected in the direction 2 shown in the figure. In each patch antenna unit, the multiple elements may be electrically connected by wiring such as striplines on a substrate. In each patch antenna unit, each of the multiple elements is spaced at intervals d shorter than half the wavelength λ of the transmitted wave. 2,s They may be spaced apart by only a certain amount. In Figure 8, each patch antenna unit may consist of two or any number of elements electrically connected.

[0074] Furthermore, as shown in Figure 8, the receiving antenna array 31 may be arranged in an array of multiple patch antenna units in the direction 1 shown in the figure. Each patch antenna unit is spaced at intervals d shorter than half the wavelength λ of the transmitted wave. 1,s They may be spaced apart by only a certain amount. In one embodiment, the receiving antenna array 31 may include two or any number of patch antenna units.

[0075] All elements included in the transmitting antenna array 24 and the receiving antenna array 31 may be arranged on the same plane (for example, on the surface layer of the same substrate). Furthermore, the transmitting antenna array 24 and the receiving antenna array 31 may be arranged in close proximity (monostatic). Additionally, directions 1 and 2 shown in Figure 8 may be geometrically orthogonal.

[0076] The transmitting antenna array 24 and receiving antenna array 31 shown in Figure 8 allow for the appropriate narrowing of the directivity of the transmitting and receiving antennas. Furthermore, by using the transmitting antenna array 24 shown in Figure 8 to control the direction of transmission for each transmitted wave (transmitted signal) at each transmission timing, a beamformer can be realized in the direction 2 shown in Figure 8. In addition, by using the receiving antenna array 31 shown in Figure 8, the direction of arrival of the reflected wave can be estimated in the direction 1 shown in Figure 8. In this way, it becomes possible to estimate the direction of arrival of the reflected wave for two substantially orthogonal angles. Therefore, it becomes possible to acquire a three-dimensional point cloud representing an object such as a passenger 200.

[0077] Next, a method for detecting the presence and location of passengers, including the driver, within the space inside a vehicle, using an electronic device 1 according to one embodiment, will be described.

[0078] Figure 9 shows an example of how the electronic device 1 according to one embodiment is installed inside a car. Figure 10 shows an example of the position in which the electronic device 1 according to one embodiment is installed inside a car, and the position of the seats arranged inside the car. The electronic device 1 according to one embodiment may be installed in the positions shown in Figures 9 and 10, for example. Figures 9 and 10 assume a right-hand drive car, which is the mainstream in Japan, that is, a car with the steering wheel mounted on the right side in the direction of travel. For example, the driver's seat may be located at position P1 shown in Figure 10. The passenger seat may be located at position P2 shown in Figure 10. The rear seat on the driver's side may be located at position P3 shown in Figure 10. The rear seat on the passenger side may be located at position P4 shown in Figure 10. On the other hand, the electronic device 1 according to one embodiment may be installed inside a left-hand drive car. Furthermore, the car in which the electronic device 1 according to one embodiment is installed is not limited to those shown in Figures 9 or 10, but may be various types of cars. For example, the automobile in which the electronic device 1 according to one embodiment is installed may have three seats as rear seats. Alternatively, the automobile in which the electronic device 1 according to one embodiment is installed may have three or more rows of seats.

[0079] As shown in Figures 9 and 10, the electronic device 1 may be installed, for example, near the driver seated in the driver's seat. Also, as shown in Figure 9, the electronic device 1 may be mounted, for example, on the car's sun visor or nearby, or for example, on the ceiling of the car (the upper part of the passenger compartment). Patent document 1, mentioned earlier, instructs that the transceiver be placed as close as possible to the driver's seat among the seats in the passenger compartment. However, in one embodiment of the electronic device 1, it is not necessary to place it as close as possible to the driver's seat among the seats in the passenger compartment.

[0080] On the other hand, in one embodiment, the electronic device 1 may be installed at a position where the distance to a person seated in each seat is different. That is, in the example shown in Figure 10, the electronic device 1 may be positioned such that the distance from the electronic device 1 to the people seated in positions P1 to P4 is different. For example, let α1 be the distance from the electronic device 1 to the person seated in the seat at position P1. Let α2 be the distance from the electronic device 1 to the person seated in the seat at position P2. Let α3 be the distance from the electronic device 1 to the person seated in the seat at position P3. Let α4 be the distance from the electronic device 1 to the person seated in the seat at position P4. In this case, the electronic device 1 may be positioned such that α1, α2, α3, and α4 are all different distances (lengths). The electronic device 1 may be positioned such that the antenna gain is sufficient at each seat from position P1 to P4.

[0081] Furthermore, in one embodiment, the electronic device 1 may be positioned such that the angles from the electronic device 1 to each seat are as different as possible. That is, in one embodiment, the electronic device 1 may be positioned such that the difference in angles from the electronic device 1 to each seat is as large as possible. With such an arrangement of the electronic device 1, the body surface of a person sitting in each seat becomes relatively visible from the electronic device 1. Therefore, from the viewpoint of signal-to-noise ratio, a person sitting in each seat becomes easier to detect by the electronic device 1.

[0082] The electronic device 1 according to one embodiment may be pre-installed in the vehicle. That is, the electronic device 1 according to one embodiment may be shipped pre-installed in the vehicle. Alternatively, the electronic device 1 according to one embodiment may be installed in the vehicle later. That is, the electronic device 1 according to one embodiment may be shipped in a state where it can be retrofitted into the vehicle.

[0083] As described above, the electronic device 1 according to one embodiment may be configured to include a radio wave sensor such as an FMCW type millimeter-wave radar sensor. The electronic device 1 according to one embodiment is installed, for example, inside the interior of a vehicle such as an automobile, and detects occupants seated inside the vehicle using a radio wave sensor such as an FMCW type millimeter-wave radar sensor. The surface of the human body is constantly undergoing minute vibrations due to body movement, breathing, and / or heartbeat. Therefore, the electronic device 1 according to one embodiment can distinguish the human body from a stationary object by detecting the movement caused by vibrations of the human body using a radio wave sensor such as a millimeter-wave radar sensor.

[0084] On the other hand, when using radio wave sensors such as millimeter-wave sensors for detection in a space that is at least partially enclosed, such as the interior of a car, the so-called multipath problem arises. Multipath is a phenomenon caused by multiple reflections and is known to occur particularly easily in enclosed spaces such as the interior of a car. Radio waves transmitted from a transmitting antenna not only travel directly between the transmitting antenna and the target object, but some are also reflected one or more times by surrounding objects before being received by a receiving antenna. If object detection is performed based on the multipath component of the radio waves that have followed extra paths, the object may be detected as being at a greater distance than it actually is. Performing signal processing based on such received signals can cause false detections or hinder correct detection. For example, when attempting to detect multiple passengers seated in a car using a radar sensor, multipath can occur due to passengers seated closer to the radar sensor. As a result, the accuracy of detecting passengers seated further away from the radar sensor may decrease. For example, if a process is performed to derive a point cloud with high intensity from the 2D Fourier transform result using constant false detection probability (CFAR) processing, passengers seated in seats closer to the radar sensor may be misdetected, resulting in passengers seated in the rear seats being misdetected.

[0085] Figure 11 shows an example of the results of detecting an occupant by a radar sensor inside a car. Figure 11 may show the signal strength obtained as a result of receiving radio waves transmitted by electronic device 1 in a situation (inside a car) as shown in Figures 9 and 10. As an example, Figure 11 shows an example of the results of performing a two-dimensional Fourier transform (2D-FFT) on a received signal detected in a situation where there is only one occupant inside the car. Figure 11 shows the results of performing two Fourier transforms on the signal received by electronic device 1. The distance component can be derived from the received signal by the first Fourier transform. The velocity component can be derived from the second Fourier transform. In the graph shown in Figure 11, the horizontal axis shows velocity and the vertical axis shows range. In the graph shown in Figure 11, the closer the color is to white, the stronger the signal strength, and the closer the color is to black, the weaker the signal strength. In the graph shown in Figure 11, the area that is close to black, which occupies most of the graph, corresponds to the noise intensity in the signal detected by electronic device 1. In Figure 11, the region labeled "Direct Wave Detection" (corresponding to a small distance) indicates the region where radio waves traveling directly between the electronic device 1 and the passenger were detected. Furthermore, as shown in Figure 11, the region labeled "Direct Wave Detection" is detected as a component with velocity. This is due to changes in the passenger's body surface caused by breathing. Thus, the passenger is detected as a component with velocity, which is due to changes in the body surface associated with breathing. Also, as shown in Figure 11, a signal with some intensity is detected in a region slightly further away than the region labeled "Direct Wave Detection" (the region labeled "Multipath Effects"). This region indicates the area where radio waves not traveling directly between the electronic device 1 and the passenger were detected, i.e., the region caused by multipath effects. Additionally, the signal components detected in the region at zero velocity or near zero velocity at the left end of the graph in Figure 11 are mainly due to reflections from stationary objects inside the vehicle. As shown in Figure 11, multipath problems arise when detection is performed using a millimeter-wave sensor inside a car.Therefore, using signals detected by millimeter-wave sensors inside a car cabin directly can lead to false detections or hinder correct detection. However, according to one embodiment of the electronic device 1, it is possible to determine the seat in which an occupant is seated with relatively high accuracy, even in environments where the effects of multipath described above occur.

[0086] Furthermore, the distance resolution of FMCW radar sensors depends on the occupied bandwidth. Typically, the distance resolution of millimeter-wave sensors is several centimeters or more. Therefore, the resolution of detection by millimeter-wave sensors is not sufficient to distinguish a person seated in a seat in a relatively narrow space such as the interior of a car. The distance between a seated occupant and the radar sensor may also depend on the occupant's sitting position and / or body type. For this reason, depending on the circumstances in which each occupant is seated, the resolution of detection by millimeter-wave sensors may be insufficient. Non-patent document 1, mentioned earlier, teaches a technique for detecting occupants in a car using machine learning to process detection signals from millimeter-wave radar. Because the radar system employed in Non-patent document 1 has relatively low angular resolution, it is limited to recognizing the row in which occupants are seated in the car interior, and does not distinguish the seat in which an occupant is seated within that row. However, according to one embodiment of electronic device 1, even with a sensor that does not have sufficient distance resolution, it is possible to distinguish the seat in which an occupant is seated with relatively high accuracy.

[0087] In one embodiment, the electronic device 1 records the detection results from a millimeter-wave radar sensor for all patterns of passengers sitting in each seat inside the vehicle, and uses this as training data to identify the seated passengers. By this method, the electronic device 1 in one embodiment can correctly identify the arrangement of passengers seated in the vehicle even in environments where multipath occurs or when using sensors with insufficient distance resolution. Therefore, according to the electronic device 1 in one embodiment, by knowing the distance from the electronic device 1 to each seat in advance, it is possible to identify the seats in the vehicle where passengers are seated.

[0088] According to one embodiment of the electronic device 1, it is possible to detect passengers seated in seats located at positions P1 to P4 in the interior of a car, for example, as shown in Figure 10. According to one embodiment of the electronic device 1, it is possible to determine whether or not a passenger is seated in at least one of the seats located at positions P1 to P4 in the interior of a car, for example, as shown in Figure 10. Furthermore, according to one embodiment of the electronic device 1, it is also possible to determine whether or not a passenger is seated in each of the seats located at positions P1 to P4 in the interior of a car, for example, as shown in Figure 10. Therefore, according to one embodiment of the electronic device 1, it is possible to detect the presence and location of people and other objects with good accuracy by transmitting and receiving radio waves in at least a partially enclosed space, such as the interior of a car.

[0089] The operation of the electronic device 1 according to one embodiment may include, for example, the following two phases: (1) Action to acquire (generate) training data (2) An operation to determine the presence and / or location of a passenger using training data. (1) above is the operation of acquiring (generating) training data in advance before actually determining whether a passenger is seated by the electronic device 1 according to one embodiment. (2) above is the operation of actually determining whether a passenger is seated by the electronic device 1 according to one embodiment using the training data generated in (1) above.

[0090] Figure 12 is a flowchart illustrating the operation of the electronic device 1 according to one embodiment. Figure 12 may represent the operation of acquiring (generating) training data as described above. That is, the operation shown in Figure 12 may represent the operation of acquiring (generating) training data in advance before the electronic device 1 according to one embodiment actually determines whether a passenger is seated.

[0091] At the start of the operation shown in Figure 12, the electronic device 1 is assumed to be installed in the passenger compartment of a car, for example, as shown in Figure 10. Furthermore, at the start of the operation shown in Figure 12, it is possible that only one passenger is seated in any of the seats in the passenger compartment of the car, for example, as shown in Figure 10, where the electronic device 1 is installed. For example, in the passenger compartment of a car, as shown in Figure 10, only one passenger may be seated in any of the seats from position P1 to position P4. In the following description, the general operation and processing of known millimeter-wave radar when transmitting and receiving radio waves may be simplified or omitted as appropriate.

[0092] When the operation shown in Figure 12 begins, the signal processing unit 10 of the electronic device 1 according to one embodiment controls the transmitting antenna 25 of the electronic device 1 to transmit a transmission wave (step S11). The transmission signal transmitted in step S11 may be, for example, a chirp signal as shown in Figure 3.

[0093] When the transmission wave is transmitted in step S11, the signal processing unit 10 controls the receiving antenna array 31 of the electronic device 1 to receive the reflected wave that the transmission wave has reflected off an object (step S12). The received signal received in step S12 may be based on a reflected wave that the transmission wave has reflected off, for example, an occupant seated in the interior of a car. Alternatively, the received signal received in step S12 may be based on a reflected wave that the transmission wave has reflected off, for example, a stationary object in the interior of a car.

[0094] When the reflected wave is received in step S12, the signal processing unit 10 acquires the received signal (ADC data) which has been converted from analog to digital by the receiving ADC 34 (step S13).

[0095] In step S13, when ADC data is acquired, the signal processing unit 10 performs distance FFT processing and velocity FFT processing (2D-FFT processing) on ​​the acquired ADC data (beat signal based on the transmitted wave and reflected wave) (step S14). In step S14, the signal processing unit 10 may perform two Fourier transforms on the acquired ADC data. The first Fourier transform derives the distance component from the received signal. The second Fourier transform derives the velocity component. The results of the processing performed in step S14 can be represented, for example, as shown in the graph in Figure 11. As described above, Figure 11 shows an example of the results of performing 2D-FFT processing on a received signal detected by a radar sensor in a situation where there is only one occupant in the passenger compartment of a car.

[0096] Next, the signal processing unit 10 may remove low-velocity components from the results of the 2D-FFT processing performed in step S14 (step S15). For example, the signal processing unit 10 may remove components caused by stationary objects with zero velocity and low-velocity components from the results of the 2D-FFT processing shown in Figure 11. The components detected as having zero velocity in the 2D-FFT processing performed in step S14 are assumed to be mainly due to reflections from stationary objects inside the vehicle. Therefore, components detected as having zero velocity in the 2D-FFT processing may be removed regardless of the presence or absence of passengers. The components detected as having zero velocity in the 2D-FFT processing are assumed to be due to the effect of performing a finite-length discrete Fourier transform. Therefore, such components are mixed in to a small extent not only in the zero-velocity bin but also in the bin corresponding to low velocity. Thus, in step S15, the signal processing unit 10 may replace the values ​​of the zero-velocity components and a certain amount of low-velocity components with an intensity of 0.

[0097] In step S15, once the low-velocity components have been removed, the signal processing unit 10 calculates the sum in the velocity axis direction (step S16). The result obtained in step S15 is a two-dimensional array of data having distance and velocity axes. In step S16, the signal processing unit 10 may calculate the sum of the velocity-direction components in this two-dimensional array of data. This allows the signal processing unit 10 to generate a one-dimensional array of data having a distance axis.

[0098] In step S16, once the sum of the data in the velocity axis direction of the two-dimensional array is calculated, the signal processing unit 10 generates a spectrogram according to one embodiment (step S17). In step S16, the signal processing unit 10 may generate a spectrogram according to one embodiment based on the results of performing the processes from step S11 to step S15 multiple times. Here, the number of times the processes from step S11 to step S15 are performed can be changed by setting. If the number of times the processes from step S11 to step S15 are performed is set too many times, it will take a long time to obtain the processing results. Therefore, the number of times the processes from step S11 to step S15 are performed can be set appropriately, taking into consideration the time it takes to obtain the processing results.

[0099] The processes performed from step S15 to step S17 can be expressed, for example, as shown in equation (1) below.

number

[0100] In equation (1) above, i is the number of 2D-FFT operations, j is the distance bin, k is the velocity bin, and k min P is the upper limit of the low-speed component. ijk This represents the result of 2D-FFT processing, R ij represents the components of the spectrogram. In this way, the signal processing unit 10 calculates a spectrogram R that shows the intensity corresponding to a predetermined distance at a predetermined time of the reflected wave.

[0101] Figure 13 shows an example of a spectrogram generated as described above. The spectrogram shown in Figure 13 was generated under the condition that only one passenger was seated in the seat inside the car, as described above. In the spectrogram shown in Figure 13, the horizontal axis represents time, and the vertical axis represents range. In the graph shown in Figure 13, the intensity of the color represents the detection intensity. In the graph shown in Figure 13, the closer the color is to white, the stronger the signal intensity, and the closer the color is to black, the weaker the signal intensity. Also, in the spectrogram shown in Figure 13, the areas with relatively strong signal intensity, indicated by solid lines on the horizontal axis, and the areas with relatively weak signal intensity, indicated by dashed lines on the horizontal axis, change over time. Such changes are due to the passenger's breathing. As shown in Figure 13, the cycle of the passenger's breathing (exhalation and inhalation) is approximately 3 seconds.

[0102] As shown in Figure 13, the region with a relatively short distance represents the detection intensity of the direct wave. Also, as shown in Figure 13, the region other than the region with a relatively short distance represents the detection intensity affected by multipath. As shown in Figure 13, it can be seen that, compared to the region showing the detection intensity of the direct wave, the component of the detection intensity affected by multipath is detected as a component at a relatively long distance, similar to the results of 2D-FFT processing. Comparing the two, it can be seen that when the direct wave is relatively strong, the multipath intensity has a strong influence, and conversely, when the direct wave intensity is relatively weak, the multipath intensity has a weak influence.

[0103] In step S17, once a spectrogram is generated, the signal processing unit 10 may generate training data by acquiring (saving) a time-averaged value (step S18). In step S18, the signal processing unit 10 may acquire (save) the time-averaged value as training data based on the results of performing the processes from step S11 to step S17 multiple times. In step S18, the signal processing unit 10 may average the time-direction components of the spectrogram generated in step S17. The length of the time axis of the spectrogram that forms the basis of the processing performed in step S18 may be sufficiently longer than the human respiratory cycle (for example, 3 seconds or more).

[0104] The training data generated in step S18 can be expressed as components of the training matrix F, for example, as shown in equation (2) below. Each column of the training matrix F is generated based on a spectrogram for the case where there is only one passenger in a seat, for example, as shown in Figure 10. Each column of the training matrix F is a vector that shows a typical distance-to-intensity pattern for each seating arrangement.

number

[0105] In equation (2) above, the variable o represents the seating arrangement in which passengers are seated, for example, as shown in Figure 10. For example, o=1 indicates the passenger seat arrangement (position P2), o=2 indicates the driver's seat arrangement (position P1), o=3 indicates the rear seat arrangement on the passenger side (position P4), and o=4 indicates the rear seat arrangement on the driver's side (position P3). o=0 may represent background data in which no passengers are seated in any of the seats. Also, R o This represents the spectrogram for a specific seating arrangement. In equation (2) above, I represents the upper limit of the number of 2D-FFT processing runs, i represents the number of 2D-FFT processing runs as in equation (1) above, and j represents the distance bin as in equation (1) above.

[0106] Once the processing in step S18 is complete, the signal processing unit 10 may change the position of the seat where only one passenger is seated in the car interior, for example, as shown in Figure 10, and repeat the operation shown in Figure 12. In this way, the signal processing unit 10 may repeat the operation shown in Figure 12 for all patterns of seat positions where only one passenger is seated in the car interior, for example, as shown in Figure 10 (i.e., for all the variables o mentioned above). The signal processing unit 10 may also perform the operation shown in Figure 12 when, for example, no passengers are seated in the car interior, for example, as shown in Figure 10. In this way, the signal processing unit 10 can generate training data (training matrix F) under each condition. The training data generated in this way may be stored in any memory.

[0107] The training data generated by the operation shown in Figure 12 may be reacquired whenever conditions such as the type of automobile and / or the installation configuration of electronic equipment 1, such as a radar sensor, change.

[0108] Figure 14 is a flowchart illustrating the operation of the electronic device 1 according to one embodiment. Figure 14 may show the operation of determining the presence and / or location of a passenger using the training data described in (2) above. That is, Figure 14 may show the operation of actually determining the presence and / or location of a passenger by the electronic device 1 according to one embodiment using the training data generated in the operation of acquiring (generating) the training data described in (1) above.

[0109] The operations from step S31 to step S37 shown in Figure 14 may be performed in the same way as the operations from step S11 to step S17 described in Figure 12.

[0110] Once a spectrogram is generated in step S37, the signal processing unit 10 may decompose the spectrogram using the training data generated by the operation shown in Figure 12 (step S38).

[0111] In step S38, the signal processing unit 10 may decompose the spectrogram generated in step S37 into the form of equation (3) using the training data. That is, in step S38, the signal processing unit 10 may approximate the spectrogram R generated in step S37 to the form of the right-hand side of equation (3).

number

[0112] In equation (3) above, R represents the spectrogram generated in step S37 based on equation (1). F represents the training matrix generated by the operation shown in Figure 12. G represents a matrix called the activation matrix.

[0113] Figure 15 shows the dimensions of matrices R, F, and G shown in equation (3) above. As shown in Figure 15, the spectrogram R is a matrix with distance and time axes. The teacher matrix F is a matrix with distance and teacher basis axes. The activation matrix G is a dimensionless matrix with teacher basis and time axes. The spectrogram R and teacher matrix F are known matrices, while the activation matrix G is an unknown matrix.

[0114] Equation (3) above shows that the spectrogram R is approximated by the product of the teacher matrix F and the activation matrix G. Therefore, in step S38, the signal processing unit 10 may derive an activation matrix G that makes the product of the teacher matrix F and the activation matrix G closest to the spectrogram R. The final generated activation matrix G is a two-dimensional matrix that shows the intensity and time at which each column of the teacher matrix F, which is the teacher basis, exists in the spectrogram R shown in equation (1) above.

[0115] In one embodiment, the signal processing unit 10 may generate an activation matrix G from the spectrogram R and the training matrix F generated by processing the received signal, for example, as follows. That is, when generating the activation matrix G, the signal processing unit 10 may use a method based on semi-supervised non-negative matrix factorization (SSNMF). Specifically, the signal processing unit 10 may prepare an array G0 as the initial array of the activation matrix G, having an appropriate array length and each element being a random positive integer. Then, the signal processing unit 10 may calculate x = F * G0 for this array G0 and quantify the residual with matrix R using a function called a distance function. For example, the signal processing unit 10 may use the Euclidean distance (D EU You may use ) to perform the calculation shown in equation (4) below.

[0116]

number

[0117] In one embodiment, the Euclidean distance (D) shown in formula (4) above is used. EU ) can be considered as the difference between R and F*G. Therefore, the signal processing unit 10 is D EU We can derive an activation matrix G that minimizes . In this case, this solution can be derived using the update formula shown in equation (5) below. Equation (5) is derived using the auxiliary function method and Jensen's inequality.

number

[0118] For example, the signal processing unit 10 controls G on the right side of equation (5) above. o,i The result obtained by substituting array G into (the left side of equation (5) above) is then used again on the right side of G. o,iThe process of substituting into the above equation (4) can be repeated. By doing so, the distance (Euclidean distance) shown in equation (4) above can be reduced. The signal processing unit 10 is D shown in equation (4) above EU The process may be terminated when the value converges to a certain value. The signal processing unit 10 then retains the activation matrix G obtained at the end of the process (stored in any memory, etc.) and may proceed to the next step.

[0119] Once the spectrogram has been decomposed in step S38 (i.e., the activation matrix G has been derived), the signal processing unit 10 may determine from the activation matrix G whether or not there are passengers and / or the position of the passengers (step S39).

[0120] As shown in Figure 15, each row of the activation matrix G corresponds to a variable o (=0~4) that represents a column of the training basis. Figure 16 shows an example of the components of the activation matrix G derived by the signal processing unit 10. Figure 16 shows the components of the activation matrix G obtained using training data on a spectrogram R generated when an occupant is seated in a seat inside a car. In the example shown in Figure 16, the activation matrix G was derived by performing the process in step S38 on the spectrogram R when an occupant is seated in the driver's seat [position P1] and the rear passenger seat [position P4] as shown in Figure 10. In the example shown in Figure 16, the derived activation matrix G is separated into a one-dimensional array row by row, and the results of plotting the rows corresponding to o=1, 2, 3, and 4 are shown. The horizontal axis of the graph shown in Figure 16 represents the frame number, and the vertical axis of the graph shown in Figure 16 represents the activation intensity.

[0121] Figure 16(A) plots the activation intensity for each frame number in the driver's seat [position P1] (corresponding to the variable o=2, which represents the column of the teacher basis in the activation matrix G). Figure 16(B) plots the activation intensity for each frame number in the passenger seat [position P2] (corresponding to the variable o=1, which represents the column of the teacher basis in the activation matrix G). Figure 16(C) plots the activation intensity for each frame number in the rear seat on the driver's side [position P3] (corresponding to the variable o=4, which represents the column of the teacher basis in the activation matrix G). Figure 16(D) plots the activation intensity for each frame number in the rear seat on the passenger side [position P4] (corresponding to the variable o=3, which represents the column of the teacher basis in the activation matrix G).

[0122] As shown in Figure 16, the activation intensity of the row components corresponding to the driver's seat [position P1] and the rear passenger seat [position P4], where an occupant is seated, is greater than that of the passenger seat [position P2] and the rear driver's seat [position P3], where an occupant is not seated. Therefore, in one embodiment, the signal processing unit 10 can determine whether or not an occupant is seated in each seat by setting thresholds, for example, as shown by the dashed lines in Figure 16. Specifically, the signal processing unit 10 may determine that an occupant is seated in the driver's seat [position P1] and the rear passenger seat [position P4]. On the other hand, the signal processing unit 10 may determine that an occupant is not seated in the passenger seat [position P2] and the rear driver's seat [position P3].

[0123] If the presence or absence of a passenger and / or the position of a passenger is determined in step S39, the signal processing unit 10 may output the result of the determination to any function unit (step S40).

[0124] In step S40, the signal processing unit 10 may indicate the presence or absence of a passenger and / or the passenger's location by displaying it, for example, on the display unit of an external device 60. For example, the signal processing unit 10 may display an image as shown in Figure 10 on the display unit of the external device 60. In this case, if the signal processing unit 10 determines that a passenger is seated at any of the positions P1 to P4, it may indicate to the user that a passenger is seated by changing the display manner of any of the positions P1 to P4. The signal processing unit 10 may also indicate to the user the seat in which the passenger is seated as at least one of any visual information, audio information, and / or tactile information. Furthermore, the signal processing unit 10 may use the information indicating the seat in which the passenger is seated for other processing, or transmit it to other devices or other functional units. For example, in one embodiment, based on the result of detecting the arrangement of the seat in which the passenger is seated, other applications may perform processing such as measuring the passenger's respiratory rate and / or heart rate, and issuing a seatbelt non-fastening warning.

[0125] As described above, in one embodiment, the signal processing unit 10 processes the spectrogram R and the base F0 and base F i Based on the teacher matrix F generated from and the activation matrix G, the activation matrix G is calculated using a distance function so as to minimize the value of Y = R - FG. Here, the basis F0 is the time-averaged basis of the spectrogram R when the object (e.g., passenger) is not present in a predetermined area (e.g., inside a vehicle of a moving object such as a car). i This refers to a situation where the subject (e.g., a passenger) is at a predetermined position X in a predetermined area (e.g., inside a vehicle, such as a car). i Let the time-averaged spectrogram R be the basis for the case where (i is an integer greater than or equal to 1).

[0126] In one embodiment, the signal processing unit 10, if the components of the activation matrix G are greater than or equal to a predetermined threshold, determines a predetermined position X in a predetermined region (for example, inside a vehicle of a moving object such as an automobile). i It may be determined that the target exists.

[0127] In one embodiment, the signal processing unit 10 may calculate the spectrogram R by adding the velocity component to the result of the 2D-FFT processing generated based on the transmitted wave and the reflected wave at predetermined distances at predetermined times. In this case, the signal processing unit 10 may perform the process of adding the velocity component to the result of the 2D-FFT processing at predetermined distances at predetermined times after removing the result of the 2D-FFT processing where the velocity is up to a predetermined magnitude.

[0128] In one embodiment, the transmitted wave may be a chirp signal generated by electromagnetic waves. In this case, the signal processing unit 10 may calculate the spectrogram R based on the value obtained by Fourier transforming the beat signal based on the transmitted wave and the reflected wave.

[0129] In one embodiment, the predetermined region described above may be, for example, the interior of a vehicle, such as an automobile. In another embodiment, the predetermined position X in the predetermined region described above i This could refer to, for example, the position of a seat in a moving vehicle such as an automobile.

[0130] According to one embodiment of the electronic device 1, it is possible to detect in real time an occupant seated in a seat located at positions P1 to P4 in the interior of a car, for example, as shown in Figure 10. Therefore, according to one embodiment of the electronic device 1, the presence and location of a person or the like can be detected with good accuracy by transmitting and receiving radio waves in at least a partially enclosed space, such as the interior of a car. According to one embodiment of the electronic device 1, even in at least a partially enclosed space, such as the interior of a car, the effects of multipath described above can be suppressed and the presence or absence of a seated occupant and / or the location of the occupant can be detected.

[0131] (Other embodiments) Other embodiments will be described below.

[0132] The electronic device 1 according to one embodiment is not limited to employing millimeter-wave radar technology. For example, the electronic device 1 according to one embodiment can be realized in the same manner as the above-described embodiment by using the FMCW method, even if it employs centimeter-wave band radio waves or terahertz waves, which are radio waves near the millimeter wave.

[0133] Furthermore, the electronic device 1 according to one embodiment is not limited to a device that detects passengers seated in seats arranged inside a vehicle as shown in Figure 10. As described above, the vehicle in which the electronic device 1 according to one embodiment is installed is not limited to those shown in Figure 9 or Figure 10, but may be various types of vehicles. In the example shown in Figure 10, the electronic device 1 according to one embodiment detected four seats in the interior of a five-seater or four-seater passenger car (driver's seat [position P1], passenger seat [position P2], rear seat on the driver's side [position P3], and rear seat on the passenger's side [position P4]). However, the electronic device 1 according to one embodiment may, for example, detect all seats in a five-seater passenger car, or seats in a three-row passenger car, or seats in a mobile vehicle with other seating arrangements.

[0134] In one embodiment, by preparing a teacher basis F0 in which there are no passengers in the vehicle interior, the spectrogram R corresponding to the five basis sets o=0,1,2,3, and4, which include the teacher basis, may be decomposed. On the other hand, in one embodiment, before processing step S38 shown in Figure 14, the background component F may be extracted from each column of the spectrogram R. o=0 Alternatively, a matrix R' may be prepared by subtracting the values. In this case, using a teacher basis F'0 consisting of o=1, 2, 3, and 4 other than o=0, the process in step S39 may be performed by setting R to R', F to F'0, and G to G' in equation (3) above.

[0135] In the embodiment described above, in the process of step S38 shown in Figure 14, the distance function is the Euclidean distance (D EU The case where ) is used was explained. However, the distance function that can be used in the process of step S38 is the Euclidean distance (DEU ) are not limited to the above. The distance function used in the processing of step S38 may be, for example, the Kullback-Leibler distance or the Itakura-Saito (IS) distance. In step S38, the signal processing unit 10 may use an update formula for the activation matrix G based on such a distance function. Thus, in one embodiment, the signal processing unit 10 may use any of the above-mentioned distance functions: the Euclidean distance, the Kullback-Leibler distance, and the Itakura-Saito distance.

[0136] In the electronic device 1 shown in Figure 2, the signal processing unit 10 was described as having the function of performing various signal processing operations. However, in one embodiment, at least a portion of the processing performed by the signal processing unit 10 may be performed by an external computer or processor, such as a cloud server.

[0137] Furthermore, the signal processing unit 10 of the electronic device 1 according to one embodiment may generate information regarding the speed of a first detection target from the reflected wave obtained by reflecting the transmitted wave, and generate information regarding the position of the first detection target based on the information regarding the speed of the first detection target and predetermined information regarding the speed of a second detection target corresponding to the location of the second detection target, which has been acquired in advance.

[0138] While this disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art will find it easy to make various modifications or alterations based on this disclosure. Therefore, it should be noted that these modifications or alterations are within the scope of this disclosure. For example, the functions included in each functional part can be rearranged in a logically consistent manner. Multiple functional parts may be combined into one or divided. The embodiments relating to this disclosure described above are not limited to being implemented strictly according to the respective embodiments, but can be implemented by combining features or omitting parts as appropriate. In other words, the contents of this disclosure can be modified and altered in various ways based on this disclosure by those skilled in the art. Therefore, these modifications and alterations are within the scope of this disclosure. For example, in each embodiment, each functional part, each means, each step, etc. can be added to other embodiments in a logically consistent manner, or replaced with each functional part, each means, each step, etc. from other embodiments. Also, in each embodiment, multiple functional parts, each means, each step, etc. can be combined into one or divided. Furthermore, the embodiments of this disclosure described above are not limited to being implemented strictly according to the respective embodiments described, but can also be implemented by combining or omitting some of the features as appropriate.

[0139] The embodiments described above are not limited to implementation as electronic device 1. For example, the embodiments described above may be implemented as a control method for a device such as electronic device 1. Furthermore, the embodiments described above may be implemented as a program executed by a device such as electronic device 1, or as a storage medium or recording medium on which a program is recorded.

[0140] Furthermore, the electronic device 1 according to the above embodiment has been described as including components that constitute a so-called radar sensor, such as a transmitting antenna array 24 and a receiving antenna array 31. However, the electronic device according to one embodiment may be implemented with a configuration such as a signal processing unit 10. In this case, the signal processing unit 10 may be implemented as having a function to process signals handled by the transmitting antenna array 24 and the receiving antenna array 31, for example. [Explanation of symbols]

[0141] 1 Electronic equipment 10 Signal Processing Unit 11 Signal generation processing unit 12 Received signal processing unit 21 Transmitting DAC 22 Transmitter Circuit 23 mm wave transmission circuit 24 Transmitting Antenna Array 31 Receiving antenna array 32 Mixer 33 Receiving circuit 34 Receiving ADC 50 Communication Interfaces 60 External equipment

Claims

1. An electronic device comprising a signal processing unit that detects an object based on a transmitted signal transmitted as a transmitted wave and a received signal received as a reflected wave of the transmitted wave reflected from the object, The signal processing unit, A spectrogram R is calculated that shows the intensity of the reflected wave corresponding to a predetermined distance at a predetermined time. The base F0 is the time-averaged base of the spectrogram R when the aforementioned object is not present in the predetermined region. The base Fi is the time-averaged basis of the spectrogram R when the object is located at a predetermined position Xi (where i is an integer of 1 or more) in the predetermined region. An electronic device that calculates the activation matrix G such that the value of Y = R - FG is minimized by using a distance function based on the spectrogram R, the teacher matrix F generated from the basis F0 and the basis Fi, and the activation matrix G.

2. The electronic device according to claim 1, wherein the signal processing unit determines that an object exists at a predetermined position Xi in the predetermined region when the components of the activation matrix G are equal to or greater than a predetermined threshold.

3. The electronic device according to claim 1, wherein the signal processing unit calculates the spectrogram R by adding the velocity components at predetermined distances at predetermined time intervals to the result of a 2D-FFT process generated based on the transmitted wave and the reflected wave.

4. The electronic device according to claim 3, wherein the signal processing unit performs a process of adding velocity components to the result of the 2D-FFT processing for predetermined distances at predetermined time intervals, after removing the result of the 2D-FFT processing where the velocity is up to a predetermined magnitude.

5. The aforementioned predetermined area is the interior of the vehicle of the moving object, The electronic device according to claim 1, wherein the predetermined position Xi in the predetermined region is the position of a seat in the vehicle.

6. The electronic device according to claim 1, wherein the signal processing unit uses one of the following as the distance function: the Euclidean distance, the KL pseudo-distance, or the Itakura-Saito pseudo-distance between R and FG.

7. The aforementioned transmitted wave is a chirp signal using electromagnetic waves. The electronic device according to claim 1, wherein the signal processing unit calculates the spectrogram R based on the value obtained by Fourier transforming the beat signals based on the transmitted wave and the reflected wave.

8. A step of detecting the target based on the transmitted signal that is transmitted as a transmitted wave and the received signal that is received as a reflected wave when the transmitted wave is reflected off the target, The steps include: calculating a spectrogram R that shows the intensity of the reflected wave corresponding to a predetermined distance at a predetermined time; The steps include: setting the base F0 as the time-averaged basis of the spectrogram R when the target is not present in the predetermined region, and setting the base Fi as the time-averaged basis of the spectrogram R when the target is present at a predetermined position Xi (where i is an integer of 1 or more) in the predetermined region, and calculating the activation matrix G using a distance function such that the value of Y = R - FG is minimized, based on the spectrogram R, the teacher matrix F generated from the base F0 and the base Fi, and the activation matrix G; A method for controlling electronic devices, including...

9. In electronic devices, A step of detecting the target based on the transmitted signal that is transmitted as a transmitted wave and the received signal that is received as a reflected wave when the transmitted wave is reflected off the target, The steps include: calculating a spectrogram R that shows the intensity of the reflected wave corresponding to a predetermined distance at a predetermined time; The steps include: setting the base F0 as the time-averaged basis of the spectrogram R when the target is not present in the predetermined region, and setting the base Fi as the time-averaged basis of the spectrogram R when the target is present at a predetermined position Xi (where i is an integer of 1 or more) in the predetermined region, and calculating the activation matrix G using a distance function such that the value of Y = R - FG is minimized, based on the spectrogram R, the teacher matrix F generated from the base F0 and the base Fi, and the activation matrix G; A program that executes something.

Images