Electronic device, method of controlling the same, and program

Abstract

To provide an electronic device capable of accurately detecting vibration of a vibrating object through transmission and reception of waves, a method of controlling the same, and a program.SOLUTION: A method of controlling an electronic device for measuring vibration of a target object based on an electromagnetic wave reflected from the target object using calibration information stored in a calibration coefficient memory is provided, the method comprising a calibration step of calibrating a measurement result of the electronic device on the basis of a result of vibration measurement of a reference vibrating body.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an electronic device, a control method for an electronic device, and a program. [Background technology]

[0002] For example, in the field of automobile-related industries, a technology for measuring the distance between a vehicle and a predetermined object is considered important. In particular, in recent years, various RADAR (Radio Detecting and Ranging) technologies have been researched, which transmit radio waves such as millimeter waves and receive the waves reflected by an object such as an obstacle to measure the distance between the object and the vehicle. The importance of such a technology for measuring the distance is expected to increase in the future with the development of technologies for assisting the driver's driving and technologies related to autonomous driving that automates a part or all of driving. Various technologies for detecting objects by transmitting and receiving radio waves such as millimeter waves have been proposed. For example, Patent Document 1 proposes a technology that can improve the detection accuracy of a detection target in a space where radio wave reflection exists.

[0003] Furthermore, a technique has been proposed for acquiring information about vibrations at the position of a specific vibration source by using the above-mentioned radar technique (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-196195 [Patent Document 2] JP 2023-108329 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, if the vibration of a vibrating body can be detected with a high degree of accuracy by transmitting and receiving waves such as millimeter waves, it is expected that this will be useful in a wide variety of fields.

[0006] An object of the present disclosure is to provide an electronic device, a control method for an electronic device, and a program that can detect vibrations of a vibrating body with high accuracy by transmitting and receiving waves. [Means for solving the problem]

[0007] A control method according to an embodiment includes the steps of: A method for controlling an electronic device that measures vibration of an object based on electromagnetic waves reflected from the object by using calibration information stored in a storage unit, comprising: The method further includes a calibration step of calibrating the measurement results of the electronic device based on the results of measuring the vibration of the reference oscillator.

[0008] A program according to an embodiment includes: An electronic device that measures vibration of an object based on electromagnetic waves reflected from the object by using calibration information stored in a storage unit, A calibration step is executed to calibrate the measurement results of the electronic device based on the result of measuring the vibration of the reference oscillator.

[0009] The electronic device according to an embodiment includes: a signal processing unit that measures vibration of an object based on electromagnetic waves reflected from the object by using calibration information stored in a storage unit; A correction processing unit that calibrates a measurement result of the electronic device based on a result of measuring the vibration of the reference oscillator; Equipped with. Effect of the Invention

[0010] According to one embodiment, it is possible to provide an electronic device, a control method for an electronic device, and a program that can detect vibrations of a vibrating body with high accuracy by transmitting and receiving waves. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating a usage mode of an electronic device according to an embodiment. [Diagram 2]1 is a functional block diagram illustrating a schematic configuration of an electronic device according to an embodiment. [Diagram 3] 1 is a diagram illustrating a configuration of a signal processed by an electronic device according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating signal processing by an electronic device according to an embodiment. [Diagram 5] FIG. 2 is a diagram illustrating signal processing by an electronic device according to an embodiment. [Figure 6] FIG. 2 is a diagram illustrating signal processing by an electronic device according to an embodiment. [Figure 7] 1A and 1B are diagrams illustrating an example of an antenna arrangement and an operation principle in an antenna array of an electronic device according to an embodiment. [Figure 8] 1 is a diagram illustrating an example of an arrangement of antennas in an antenna array of an electronic device according to an embodiment. [Figure 9] 11A and 11B are diagrams illustrating an example of a detection result of a vibrator by the electronic device according to an embodiment. [Figure 10] 1 is a diagram illustrating an example of vibration detection by an electronic device according to an embodiment; [Figure 11A] 11 is a graph showing an example of a result of vibration detection by a radar sensor. [Figure 11B] 1 is a graph showing an example of a result of vibration detection by a laser Doppler vibrometer. [Figure 12] 11 is a graph showing an example of a calculation result of a finite element method according to an embodiment. [Figure 13] 1 is a diagram showing an example of a relationship between an FOV and a reference oscillator in an electronic device according to an embodiment; [Figure 14] 10 is a flowchart for explaining generation of data on average vibration displacement of a reference vibration body. [Figure 15] 10 is a flowchart illustrating an operation of an electronic device according to an embodiment. [Figure 16] FIG. 11 is a diagram illustrating an example of a result of processing according to an embodiment. [Figure 17] 13A and 13B are diagrams illustrating an example of a vibrating body according to another embodiment. [Figure 18]13A and 13B are diagrams illustrating an example of vibration displacement of a vibrating body according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, one embodiment will be described with reference to the drawings.

[0013] In the present disclosure, an "electronic device" may be a device that is driven by electricity. Furthermore, a "user" may be a person (typically a human) or an animal that uses an electronic device according to an embodiment and / or a system including the electronic device. The user may include a person who detects vibrations of a human body, a living thing, or various objects by using an electronic device according to an embodiment. Furthermore, an "object" may be a person or thing (a monitoring target, for example, a human or a living thing, or various objects) that is monitored by an electronic device according to an embodiment. Furthermore, a user may include an object. In the present disclosure, an "object" may include, for example, an automobile, an automobile engine, a motor, a motorcycle, a ship, a building, an apartment building or other structure, a bridge, a road, a highway, a structure under construction, a tunnel, a machine tool, and a shovel.

[0014] The electronic device according to an embodiment can detect the heartbeat of a target such as a human being present around the electronic device. Therefore, the electronic device according to an embodiment can be used in specific facilities used by people who engage in social activities, such as companies, hospitals, nursing homes, schools, sports gyms, and nursing homes. For example, in a company, it is very important to understand and / or manage the health of employees. Similarly, in a hospital, it is very important to understand and / or manage the health of patients and medical professionals, and in a nursing home, it is very important to understand and / or manage the health of residents and staff. The electronic device according to an embodiment can be used in any facility where it is desired to understand and / or manage the health of a target, and is not limited to the above-mentioned facilities such as companies, hospitals, and nursing homes. The facility may include, for example, a non-commercial facility such as a user's home. The electronic device according to an embodiment can be used in any facility, not limited to indoors, but may be used outdoors. For example, the electronic device according to an embodiment can be used in a moving body such as a train, bus, or airplane, as well as in a station or a boarding area. Moreover, the electronic device according to the embodiment may be used in a moving body such as an automobile, an airplane, or a ship, a hotel, a user's home, a living room in the home, a bathroom, a toilet, or a bedroom, etc. The electronic device according to the embodiment may be used to measure the heart rates of cows, pigs, or other livestock or animals in a zoo, a ranch, a farm, or the like.

[0015] The electronic device according to an embodiment may be used, for example, in a nursing facility or the like, for detecting or monitoring the heartbeat of a target such as a person requiring nursing care or a person requiring care. In addition, the electronic device according to an embodiment may issue a predetermined warning to the target and / or other people when an abnormality is found in the heartbeat of the target such as a person requiring nursing care or a person requiring care. Therefore, according to the electronic device according to an embodiment, for example, the target and / or staff of a nursing facility or the like may recognize that an abnormality is found in the pulse of a target such as a person requiring nursing care or a person requiring care. On the other hand, the electronic device according to an embodiment may notify the target and / or other people when an abnormality is not found (for example, recognized as normal) in the heartbeat of a target such as a person requiring nursing care or a person requiring care. Therefore, according to the electronic device according to an embodiment, for example, the target and / or staff of a nursing facility or the like may recognize that the pulse of a target such as a person requiring nursing care or a person requiring care is normal. An electronic device according to one embodiment may, from the heart rate of a monitored person or animal, determine the heart rate interval (RR interval = RRI in an electrocardiogram), detect dozing or other distracted driving and estimate signs of such driving, estimate the level of alertness, estimate the level of fatigue, or identify the monitored person or animal.

[0016] Moreover, the electronic device according to an embodiment may detect the pulse of animals other than humans. The electronic device according to an embodiment described below will be described as detecting the vibration of a speaker (loudspeaker) as the detection target by a sensor based on a technology such as millimeter wave radar, as an example. Note that the electronic device configured according to the present disclosure may be used to measure the heart rate or respiration of a human or animal, or the vibration of a building or machine, or any other measurement object, after being calibrated based on the vibration of the speaker as described later.

[0017] The electronic device according to an embodiment can detect vibrations such as the pulse of a living organism such as a human or an animal, as well as vibrations of various objects. Here, the various objects may include living organisms such as a human or an animal, or may include any object other than a living organism such as a human or an animal. For example, the electronic device according to an embodiment may detect vibrations of various electronic devices and / or vibrations of a part of various electronic devices. Here, the vibrations of various electronic devices may include vibrations caused by any vibrating body, such as vibrations caused by the operation of a machine installed in a factory, vibrations of a tool, or vibrations of a building. In addition, the detection target may include, for example, automobiles, automobile engines, motors, motorcycles, ships, buildings, apartments, other buildings, bridges, roads, highways, buildings under construction, tunnels, machine tools, and shovels.

[0018] The electronic device according to an embodiment may be installed on any stationary object or any moving object. The electronic device according to an embodiment can transmit a transmission wave to the surroundings of the electronic device from a transmission antenna. The electronic device according to an embodiment can receive a reflected wave of the transmission wave from a reception antenna. At least one of the transmission antenna and the reception antenna may be provided in the electronic device, or may be provided in, for example, a radar sensor or the like.

[0019] Hereinafter, the electronic device according to the embodiment will be described as being stationary. The electronic device according to the embodiment may be installed in a moving body such as an automobile. The electronic device according to the embodiment may be installed in a moving body such as an automobile to detect vibrations such as the heartbeat of a passenger riding in the moving body. On the other hand, an object whose vibration is detected by the electronic device according to the embodiment may be stationary, may be moving, or may vibrate in a stationary state. The electronic device according to the embodiment can measure the distance between the electronic device and an object in a situation where the object around the electronic device may move, similar to a normal radar sensor. The electronic device according to the embodiment can measure the distance between the electronic device and an object even if both the electronic device and the object are stationary.

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic device according to an embodiment will be described in detail below with reference to the drawings. First, an example of object detection by the electronic device according to an embodiment will be described.

[0021] Fig. 1 is a diagram for explaining an example of a usage mode of an electronic device according to an embodiment. Fig. 1 shows an example of an electronic device having a function of a sensor and including a transmitting antenna and a receiving antenna according to an embodiment.

[0022] As shown in FIG. 1, the electronic device 1 according to an 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. Also, the receiving unit may include a receiving antenna array 31. Specific configurations of the electronic device 1, the transmitting unit, and the receiving unit will be described later. For ease of viewing, FIG. 1 shows a state in which the electronic device 1 includes a transmitting antenna array 24 and a receiving antenna array 31. Also, the electronic device 1 may include at least one of the other functional units, such as at least a part of the signal processing unit 10 (FIG. 2) included in the electronic device 1, as appropriate. Also, the electronic device 1 may include at least one of the other functional units, such as at least a part of the signal processing unit 10 (FIG. 2) included in the electronic device 1, outside the electronic device 1. In FIG. 1, the electronic device 1 may be moving, or may be stationary without moving.

[0023] In the example shown in FIG. 1, the electronic device 1 is shown in a simplified form with a transmitting section including a transmitting antenna array 24 and a receiving section including a receiving antenna array 31. The electronic device 1 may include, for example, a plurality of transmitting sections and / or a plurality of receiving sections. The transmitting section may include a transmitting antenna array 24 consisting of a plurality of transmitting antennas. Furthermore, the receiving section may include a receiving antenna array 31 consisting of a plurality of receiving antennas. Here, the positions at which the transmitting section and / or the receiving section are installed in the electronic device 1 are not limited to the positions shown in FIG. 1, and may be other positions as appropriate. Furthermore, the number of transmitting sections and / or receiving sections may be any number equal to or greater than one, depending on various conditions (or requirements) such as the detection range and / or detection accuracy of vibration by the electronic device 1.

[0024] As described below, the electronic device 1 transmits electromagnetic waves as transmission waves from the transmitting antenna array 24. For example, if a specific object (e.g., the target 200 shown in FIG. 1) is present around the electronic device 1, at least a part of the transmission wave transmitted from the electronic device 1 is reflected by the object and becomes a reflected wave. Then, by receiving such a reflected wave, for example, by the receiving antenna array 31 of the electronic device 1, the electronic device 1 can detect the object as a target.

[0025] The electronic device 1 equipped with the transmitting antenna array 24 may typically be a RADAR (Radio Detecting and Ranging) sensor that transmits and receives radio waves. However, the electronic device 1 is not limited to a radar sensor. The electronic device 1 according to an embodiment may be a sensor based on, for example, a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) technology using light waves. Such sensors may be configured to include, for example, a patch antenna. Since technologies such as RADAR and LIDAR are already known, detailed descriptions thereof may be appropriately simplified or omitted. Furthermore, the electronic device 1 according to an embodiment may be a sensor based on a technology that detects an object by transmitting and receiving, for example, sound waves or ultrasonic waves.

[0026] The electronic device 1 shown in FIG. 1 receives, from the receiving antenna array 31, a reflected wave of a transmission wave transmitted from the transmitting antenna array 24. In this way, the electronic device 1 can detect a predetermined object 200 existing within a predetermined distance from the electronic device 1 as a target. For example, as shown in FIG. 1, the electronic device 1 can measure a distance L between the electronic device 1 and the predetermined object 200. The electronic device 1 can also measure the relative speed between the electronic device 1 and the predetermined object 200. Furthermore, the electronic device 1 can also measure the direction (arrival angle θ) in which the reflected wave from the predetermined object 200 arrives at the electronic device 1.

[0027] In Fig. 1, the XY plane may be, for example, a plane that is approximately parallel to the ground surface. In this case, the positive direction of the Z axis shown in Fig. 1 may indicate a vertically upward direction. In Fig. 1, the electronic device 1 may be disposed on a plane that is parallel to the XY plane. Also, in Fig. 1, the target 200 may be, for example, standing on the ground surface that is approximately parallel to the XY plane.

[0028] Here, the target 200 may be, for example, a human being present around the electronic device 1. The target 200 may be a living thing other than a human being, such as an animal present around the electronic device 1. The target 200 may include, for example, an automobile, an automobile engine, a motor, a motorcycle, a ship, a building, an apartment building, or other buildings, a bridge, a road, a highway, a building under construction, a tunnel, a machine tool, and a shovel present around the electronic device 1. As described above, the target 200 may be moving, stopped, or stationary. In the present disclosure, the object detected by the electronic device 1 includes not only inanimate objects such as any object, but also living things such as people, dogs, cats, horses, and other animals. The object detected by the electronic device 1 of the present disclosure may include targets including people, objects, and animals detected by radar technology. In the present disclosure, the targets may include people, objects, and animals. Hereinafter, the object such as the target 200 present around the electronic device 1 will be described assuming that it is a living or inanimate object. The electronic device 1 according to one embodiment detects vibrations of an object such as the target 200. Therefore, hereinafter, the "target 200" will also be referred to as a "vibrating body 200" as appropriate.

[0029] 1, the ratio between the size of the electronic device 1 and the size of the target 200 does not necessarily indicate the actual ratio. Also, in FIG. 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 of 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 as not to be visible from the outside of the electronic device 1.

[0030] In the following, as a typical example, the transmitting antenna of the electronic device 1 will be described as transmitting radio waves in a frequency band such as millimeter waves (30 GHz or higher) or quasi-millimeter waves (for example, around 20 GHz to 30 GHz). On the other hand, the transmitting antenna of the electronic device 1 may transmit radio waves having a frequency bandwidth of 4 GHz, such as 77 GHz to 81 GHz. In addition, the transmitting antenna of the electronic device 1 may transmit radio waves of a high frequency (for example, 30 GHz to 300 GHz) equal to or higher than the millimeter wave band.

[0031] 2 is a functional block diagram illustrating an example of the configuration of the electronic device 1 according to an embodiment. An example of the configuration of the electronic device 1 according to an embodiment will be described below.

[0032] When measuring distances and the like using a millimeter wave radar, a frequency modulated continuous wave radar (hereinafter, referred to as FMCW radar) is often used. In an FMCW radar, a transmission signal is generated by sweeping the frequency of radio waves to be transmitted. Therefore, in a millimeter wave FMCW radar using radio waves in a frequency band of, for example, 79 GHz, the frequency of the radio waves used has a frequency bandwidth of 4 GHz, for example, 77 GHz to 81 GHz. A radar in the 79 GHz frequency band has a feature that the available frequency bandwidth is wider than other millimeter wave / quasi-millimeter wave radars in frequency bands of, for example, 24 GHz, 60 GHz, and 76 GHz. Hereinafter, such an embodiment will be described as an example.

[0033] The FMCW radar system used in the present disclosure may include an FCM (Fast-Chirp Modulation) system that transmits a chirp signal at a shorter period than normal. The signal generated by the electronic device 1 is not limited to an FMCW signal. The signal generated by the electronic device 1 may be a signal of various systems other than the FMCW system. The transmission signal sequence stored in an arbitrary storage unit may differ depending on these various systems. For example, in the case of the radar signal of the above-mentioned FMCW system, a signal whose frequency increases and decreases for each time sample may be used. Since the above-mentioned various systems can be appropriately applied using known technologies, a more detailed description will be omitted.

[0034] As shown in FIG. 2, the electronic device 1 according to the embodiment includes a signal processing unit 10. The signal processing unit 10 may include a signal generation processing unit 11, a received signal processing unit 12, a correction processing unit 13, a calibration coefficient memory 14, and a waveform analysis processing unit 15. The signal generation processing unit 11 performs processing to generate a transmission signal transmitted from the electronic device 1. The received signal processing unit 12 can perform various signal processing on a received signal received by the electronic device 1. The correction processing unit 13 can perform processing to correct the result of signal processing performed by the received signal processing unit 12. The calibration coefficient memory 14 stores data (e.g., calibration coefficients or correction values) based on the result of correction processing performed by the correction processing unit 13. The waveform analysis processing unit 15 can perform, for example, waveform analysis processing on the result of correction performed by the correction processing unit 13. The signal generation processing unit 11, the received signal processing unit 12, the correction processing unit 13, the calibration coefficient memory 14, and the waveform analysis processing unit 15 will be described further below as appropriate. In this embodiment, the calibration coefficient memory 14 will be described as being included in the signal processing unit 10, but the calibration coefficient memory 14 may be provided outside the electronic device 1. Calibration coefficient memory 14 may be connected to electronic device 1 via a network that is wired, wireless, or a combination of these, and may transmit data in calibration coefficient memory 14 to correction processing unit 13 or the like of electronic device 1. Calibration coefficient memory 14 may be a storage medium that is removable from electronic device 1, and data in calibration coefficient memory 14 may be transmitted from the storage medium to correction processing unit 13 or the like of electronic device 1.

[0035] The electronic device 1 according to an embodiment includes a transmission DAC 21, a transmission circuit 22, a millimeter wave transmission circuit 23, and a transmission antenna array 24 as a transmission unit. The electronic device 1 according to an embodiment includes a reception antenna array 31, a mixer 32, a reception circuit 33, and a reception ADC 34 as a reception unit. The electronic device 1 according to an embodiment may not include at least one of the functional units shown in FIG. 2, or may include a functional unit other than the functional unit shown in FIG. 2. The electronic device 1 shown in FIG. 2 may be configured using a circuit basically configured similarly to a general radar using electromagnetic waves such as a millimeter wave band. On the other hand, in the electronic device 1 according to an embodiment, the signal processing by the signal processing unit 10 may include processing different from that of a conventional general radar.

[0036] The signal processing unit 10 included in the electronic device 1 according to an 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 processes on 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 realized as one processor collectively, as several processors, or as individual processors. The processor may be realized as a single integrated circuit. The integrated circuit is also called an IC (Integrated Circuit). The processor may be realized as a plurality of integrated circuits and discrete circuits connected to each other so as to be able to communicate with each other. The processor may be realized based on various other known technologies. In an embodiment, the signal processing unit 10 may be configured as, for example, a CPU (hardware) and a program (software) executed by the CPU. At least a part of each functional unit constituting the electronic device 1 according to an embodiment may be configured by a specific means in which software and hardware resources work together. The signal processing unit 10 may include a storage unit (memory) necessary for the operation of the signal processing unit 10 as appropriate.

[0037] 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 an 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 (linear chirp signal) whose frequency changes periodically and linearly. For example, the signal generation processing unit 11 may generate a chirp signal whose frequency increases periodically and linearly from 77 GHz to 81 GHz over time. Also, 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 over time. The signal generated by the signal generation processing unit 11 may be set in advance in, for example, the signal processing unit 10. Also, the signal generated by the signal generation processing unit 11 may be stored in advance in, for example, an arbitrary storage unit in the signal processing unit 10. Since chirp signals used in technical fields such as radar are known, a more detailed description will be appropriately simplified or omitted. The signal generated by the signal generating and processing unit 11 is supplied to the transmitting DAC 21. For this reason, the signal generating and processing unit 11 may be connected to the transmitting DAC 21.

[0038] The transmission DAC (digital-analog converter) 21 has a function of converting the digital signal supplied from the signal generating processing unit 11 into an analog signal. The transmission DAC 21 may be configured to include a general digital-analog converter. The signal converted into an analog signal by the transmission DAC 21 is supplied to the transmission circuit 22. For this reason, the transmission DAC 21 may be connected to the transmission circuit 22.

[0039] The transmission circuit 22 has a function of converting the signal converted into an analog signal by the transmission DAC 21 into an intermediate frequency (IF) band. The transmission circuit 22 may be configured to include a general IF band transmission circuit. The signal processed by the transmission circuit 22 is supplied to the millimeter wave transmission circuit 23. For this reason, the transmission circuit 22 may be connected to the millimeter wave transmission circuit 23.

[0040] The millimeter wave transmission circuit 23 has a function of transmitting the signal processed by the transmission circuit 22 as a millimeter wave (RF wave). The millimeter wave transmission circuit 23 may be configured to include a general millimeter wave transmission circuit. The signal processed by the millimeter wave transmission circuit 23 is supplied to the transmission antenna array 24. Therefore, the millimeter wave transmission circuit 23 may be connected to the transmission antenna array 24. The signal processed by the millimeter wave transmission circuit 23 is also supplied to the mixer 32. Therefore, the millimeter wave transmission circuit 23 may also be connected to the mixer 32.

[0041] The transmitting antenna array 24 is an array of a plurality of transmitting antennas. In Fig. 2, the configuration of the transmitting antenna array 24 is shown in a simplified form. 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 be configured to include a transmitting antenna array used in a general millimeter wave radar.

[0042] In this manner, the electronic device 1 according to the embodiment includes a transmitting antenna (the transmitting antenna array 24), and can transmit a transmitting signal (for example, a transmitting chirp signal) from the transmitting antenna array 24 as a transmitting wave.

[0043] For example, as shown in FIG. 2, a case is assumed where an object such as a vibrating body 200 is present around the electronic device 1. At least a portion of the vibrating body 200 may generate vibration. In such a situation, at least a portion of the transmission wave transmitted from the transmitting antenna array 24 is reflected by the object such as the vibrating body 200. At least a portion of the transmission wave transmitted from the transmitting antenna array 24 that is reflected by the object such as the vibrating body 200 may be reflected toward the receiving antenna array 31.

[0044] The receiving antenna array 31 receives the reflected wave. Here, the reflected wave may be at least a part of the transmission wave transmitted from the transmitting antenna array 24 that is reflected by an object such as the vibrating body 200.

[0045] The receiving antenna array 31 is an array of multiple receiving antennas. In Fig. 2, the configuration of the receiving antenna array 31 is shown in a simplified form. The receiving antenna array 31 receives reflected waves of the transmission waves transmitted from the transmitting antenna array 24. The receiving antenna array 31 may be configured to include a receiving antenna array used in a general millimeter wave radar. The receiving antenna array 31 supplies a reception signal received as a reflected wave to the mixer 32. For this reason, the receiving antenna array 31 may be connected to the mixer 32.

[0046] The mixer 32 converts the signal (transmission signal) processed by the millimeter wave transmission circuit 23 and the reception signal received by the reception antenna array 31 into an intermediate frequency (IF) band. The mixer 32 may be configured to include a mixer used in a typical millimeter wave radar. The mixer 32 supplies a signal generated as a result of the synthesis to the reception circuit 33. For this reason, the mixer 32 may be connected to the reception circuit 33.

[0047] The receiving circuit 33 has a function of performing analog processing on 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.

[0048] The receiving ADC (analog-digital converter) 34 has a function of converting an analog signal supplied from the receiving circuit 33 into a digital signal. The receiving ADC 34 may be configured to include a general analog-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.

[0049] The reception signal processing unit 12 of the signal processing unit 10 has a function of performing various processes on the digital signal supplied from the reception ADC 34. For example, the reception signal processing unit 12 calculates the distance from the electronic device 1 to an object such as the vibrating body 200 based on the digital signal supplied from the reception ADC 34 (distance measurement). Also, the reception signal processing unit 12 calculates the relative speed of the object such as the vibrating body 200 with respect to the electronic device 1 based on the digital signal supplied from the reception ADC 34 (speed measurement). Furthermore, the reception signal processing unit 12 calculates the azimuth angle of the object such as the vibrating body 200 as seen from the electronic device 1 based on the digital signal supplied from the reception ADC 34 (angle measurement or arrival angle estimation). Specifically, I / Q converted data may be input to the reception signal processing unit 12. By inputting such data, the reception signal processing unit 12 performs fast Fourier transform (2D-FFT) in the range direction and the velocity direction, respectively. Thereafter, the reception signal processing unit 12 may suppress false alarms and make the probability constant by removing noise points using, for example, processing such as CFAR (Constant False Alarm Rate).The reception signal processing unit 12 may obtain the position of an object such as the vibrating body 200 by estimating the arrival angle for points that satisfy the CFAR criteria.Information generated as a result of distance, speed, and angle measurement by the reception signal processing unit 12 may be supplied to the correction processing unit 13.

[0050] The correction processing unit 13 corrects the information generated by the received signal processing unit 12. The correction processing by the correction processing unit 13 will be described further below. The information on the vibration of the vibrating body corrected by the correction processing unit 13 may be supplied to a calibration coefficient memory 14 and / or a waveform analysis processing unit 15, etc.

[0051] Calibration coefficient memory 14 stores data based on the results of the correction process performed by correction processor 13 (for example, calibration coefficients or correction values).

[0052] The waveform analysis processing unit 15 performs a process of analyzing the vibration waveform by performing various calculation processes and / or arithmetic processes on information on the vibration of the vibrating body supplied from the correction processing unit 13 or the calibration coefficient memory 14. The various calculation processes and / or arithmetic processes by the waveform analysis processing unit 15 will be described further below. The waveform information analyzed by the waveform analysis processing unit 15 may be supplied to, for example, a communication interface 50. For this reason, the waveform analysis processing unit 15 and / or the signal processing unit 10 may be connected to the communication interface 50. The 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.

[0053] The communication interface 50 includes 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 at least one of information regarding the position, speed, and angle of an object such as the vibrating body 200 to the external device 60 as a signal such as a CAN (Controller Area Network). For example, at least one of information regarding the position, speed, and angle of an object such as the vibrating body 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.

[0054] As shown in FIG. 2, the electronic device 1 according to an embodiment may be connected to an external device 60 via a communication interface 50 in a wired or wireless manner. In an embodiment, the external device 60 may be configured to include any computer and / or any control device. The electronic device 1 according to an embodiment may also be configured to include the external device 60. The external device 60 may have various configurations depending on the manner in which information on vibrations detected by the electronic device 1 is used. Therefore, a more detailed description of the external device 60 will be omitted.

[0055] FIG. 3 is a diagram for explaining an example of a chirp signal generated by the signal generation processing unit 11 of the signal processing unit 10. In FIG.

[0056] FIG. 3 shows the time structure of one frame when the FCM (Fast-Chirp Modulation) method is used. FIG. 3 shows an example of a received signal in the FCM method. FCM is a method in which chirp signals shown as c1, c2, c3, c4, ..., cn in FIG. 3 are repeated at relatively short intervals (for example, longer than the round-trip time between the electromagnetic radar and the target calculated from the maximum ranging distance). In FCM, for convenience of signal processing of the received signal, transmission and reception processing is often performed by dividing it into subframe units as shown in FIG. 3.

[0057] In Fig. 3, the horizontal axis represents the elapsed time, and the vertical axis represents the frequency. In the example shown in Fig. 3, the signal generation processing unit 11 generates a linear chirp signal whose frequency changes periodically and linearly. In Fig. 3, each chirp signal is shown as c1, c2, c3, c4, ..., cn. As shown in Fig. 3, in each chirp signal, the frequency increases linearly with the passage of time.

[0058] In the example shown in FIG. 3, several chirp signals such as c1, c2, c3, c4, ..., cn are included to form one subframe. That is, subframe 1 and subframe 2 shown in FIG. 3 are each configured to include several chirp signals such as c1, c2, c3, c4, ..., cn. Also, in the example shown in FIG. 3, several subframes such as subframe 1, subframe 2, ..., subframe N are included to form one frame (1 frame). That is, one frame shown in FIG. 3 is configured to include N subframes. Also, one frame shown in FIG. 3 may be frame 1, followed by frame 2, frame 3, ..., etc. Each of these frames may be configured to include N subframes, similar to frame 1. Also, a frame interval of a predetermined length may be included between the frames. One frame shown in FIG. 3 may be, for example, about 30 milliseconds to 50 milliseconds long.

[0059] In the electronic device 1 according to an embodiment, the signal generation processing unit 11 may generate a transmission signal as an arbitrary number of frames. Also, some chirp signals are omitted in Fig. 3. In this manner, the relationship between the time and frequency of the transmission signal generated by the signal generation processing unit 11 may be stored as various setting parameters in, for example, a storage unit of the signal processing unit 10.

[0060] In this manner, the electronic device 1 according to an embodiment may transmit a transmission signal consisting of subframes including a plurality of chirp signals. Also, the electronic device 1 according to an embodiment may transmit a transmission signal consisting of a frame including a predetermined number of subframes.

[0061] Hereinafter, the electronic device 1 will be described as transmitting a transmission signal having a frame structure as shown in FIG. 3. However, the frame structure as shown in FIG. 3 is an example, and for example, the chirp signal included in one subframe may be arbitrary. That is, in one embodiment, the signal generation processing unit 11 may generate a subframe including an arbitrary number (for example, an arbitrary multiple) of chirp signals. Also, the subframe structure as shown in FIG. 3 is an example, and for example, the subframe included in one frame may be arbitrary. That is, in one embodiment, the signal generation processing unit 11 may generate a frame including an arbitrary number (for example, an arbitrary multiple) of subframes. The signal generation processing unit 11 may generate signals of different frequencies. The signal generation processing unit 11 may generate a plurality of discrete signals having different bandwidths of frequency f.

[0062] Fig. 4 is a diagram showing, in another aspect, a part of the subframe shown in Fig. 3. Fig. 4 shows each sample of the received signal that has received the transmission signal shown in Fig. 3 as a result of 2D-FFT (Two Dimensional Fast Fourier Transform) processing performed by the received signal processing unit 12 (Fig. 2) of the signal processing unit 10.

[0063] As shown in Fig. 4, chirp signals c1, c2, c3, c4, ..., cn are stored in each subframe such as subframe 1, ..., subframe N. In Fig. 4, each chirp signal c1, c2, c3, c4, ..., cn is composed of samples represented by squares arranged in the horizontal direction. The received signal shown in Fig. 4 is subjected to 2D-FFT, CFAR, and / or integrated signal processing of each subframe by the received signal processing unit 12 shown in Fig. 2.

[0064] FIG. 5 is a diagram showing an example in which a group of points on a range-Doppler (distance-velocity) plane is calculated as a result of 2D-FFT, CFAR, and integrated signal processing of each subframe being performed in the received signal processing unit 12 shown in FIG. 2.

[0065] In FIG. 5, the horizontal direction represents range, and the vertical direction represents velocity. The filled squares s1 in FIG. 5 represent point clouds indicating signals that exceed the CFAR threshold processing. The unfilled squares s2 in FIG. 5 represent bins (2D-FFT samples) without point clouds that do not exceed the CFAR threshold. The points on the range-Doppler plane calculated in FIG. 5 have their orientation from the radar calculated by direction estimation, and the position and velocity on a two-dimensional plane are calculated as a point cloud indicating an object such as the vibrating body 200. Here, the direction estimation may be calculated by a beamformer and / or a subspace method. Representative subspace method algorithms include MUSIC (MUltiple SIgnal Classification) and ESPRIT (Estimation of Signal Parameters via Rotation Invariance Technique).

[0066] Fig. 6 is a diagram showing an example of the result of conversion of point cloud coordinates from the range-Doppler plane shown in Fig. 5 to the XY plane after the received signal processing unit 12 performs direction estimation. The XY plane shown in Fig. 6 may be the same as the XY plane shown in Fig. 1. As shown in Fig. 6, the received signal processing unit 12 can plot a point cloud PG on the XY plane. Here, the point cloud PG is composed of each point P. Furthermore, each point P has an angle θ and a radial velocity Vr in polar coordinates.

[0067] The reception signal processing unit 12 detects an object present within the range where the transmission wave is transmitted based on at least one of the results of the 2D-FFT and the angle estimation. The reception signal processing unit 12 may perform object detection by, for example, clustering processing based on the estimated distance information, speed information, and angle information. As an algorithm used for clustering data, for example, DBSCAN (Density-based spatial clustering of applications with noise) is known. This is an algorithm that performs clustering based on density. In the clustering processing, for example, the average power of the points constituting the detected object may be calculated. The distance information, speed information, angle information, and power information of the object detected in the reception signal processing unit 12 may be supplied to an external device 60 or the like via a communication interface 50, for example.

[0068] 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, for example, an electric wave. The receiving antenna array 31 receives a reflected wave of the transmission wave. The signal processing unit 10 detects an object (for example, an object such as the vibrating body 200) that reflects the transmission wave, based on the transmission signal transmitted as the transmission wave and the reception signal received as the reflected wave.

[0069] Next, the estimation of the direction of an incoming wave (an incoming reflected wave) by the antenna array of the electronic device 1 according to an embodiment will be further described.

[0070] 7 is a diagram for explaining the configuration of the receiving antenna array 31 of the electronic device 1 according to an embodiment, and the principle of estimating the direction of an incoming wave by the receiving antenna array 31. FIG. 7 shows an example of reception of radio waves by the receiving antenna array 31.

[0071] As shown in Fig. 7, the receiving antenna array 31 may be a linear arrangement of sensors such as receiving antennas. As shown in Fig. 7, in one embodiment, the receiving antenna array 31 may include a plurality of receiving antennas arranged in a linear arrangement. In Fig. 7, the receiving antenna array 31 includes antenna x 1 , x 2 , x 3 , …, x M A plurality of antennas such as these are indicated by small circles. The receiving antenna array 31 may be composed of any number of antennas. As shown in FIG. 7, the plurality of antennas constituting the receiving antenna array 31 are arranged at an interval of the array pitch d. A sensor array in which sensors (antennas, ultrasonic transducers, microphones, etc.) corresponding to various physical waves are arranged in an array in this manner is also called a Uniform Linear Array (ULA). As shown in FIG. 7, physical waves (electromagnetic waves, sound waves, etc.) are transmitted along a line having a wavelength of, for example, θ 1 and θ 2 Here, θ 1 and θ 2 may be the above-mentioned angle of arrival. 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 measurements between the sensors according to the direction of arrival of the physical wave. This method of estimating the direction of arrival of the wave is also referred to as angle of arrival estimation or direction of arrival (DoA).

[0072] In the electronic device 1 according to an embodiment, at least one of the transmitting antenna array 24 and the receiving antenna array 31 may be a linear array of multiple antennas. This allows, for example, a millimeter wave radar to appropriately narrow the directivity when transmitting and receiving radio waves. When transmitting a transmission wave, the direction of the transmission beam is often controlled by a beamformer. On the other hand, when receiving a reflected wave, the arrival direction of the reflected wave is often estimated by a subspace method (such as the above-mentioned MUSIC and ESPRIT) rather than by a beamformer. In the beamformer and subspace method, in a ULA as shown in FIG. 7, a phase difference occurs in the measurement values ​​between sensors depending on the arrival direction of electromagnetic waves arriving from various directions. Therefore, the arrival direction of the reflected wave can be estimated by utilizing the phase difference.

[0073] Next, the estimation of angles of incoming waves in two directions by the antenna array of the electronic device 1 according to an embodiment will be further described.

[0074] FIG. 8 is a diagram showing an example of an antenna arrangement for estimating directions of arrival at two orthogonal angles.

[0075] As shown in FIG. 8, in the electronic device 1 according to an embodiment, the transmitting antenna array 24 and / or the receiving antenna array 31 may include an array of a plurality of patch antenna units.

[0076] In the transmitting antenna array 24 shown in FIG. 8, one patch antenna unit may be configured to include a plurality of elements electrically connected in a direction 1 shown in the figure. In each patch antenna unit, the plurality of elements may be electrically connected by wiring such as a strip line on a substrate. In each patch antenna unit, each of the plurality of elements is spaced apart at an interval d shorter than half the wavelength λ of the transmission wave. 1,t 8, each patch antenna unit may have any number of elements, two or more, electrically connected.

[0077] 8, the transmitting antenna array 24 may be configured by arraying a plurality of patch antenna units in a direction 2 shown in the figure. The patch antenna units are spaced apart from each other by an interval d shorter than half the wavelength λ of the transmitting wave. 2,t In one embodiment, the transmit antenna array 24 may include any number of patch antenna units greater than or equal to two.

[0078] As shown in Fig. 8, in one embodiment, the receiving antenna array 31 may be a modified version of the arrangement of the elements in the transmitting antenna array 24. That is, in the receiving antenna array 31 shown in Fig. 8, one patch antenna unit may be configured to include a plurality of elements electrically connected in the direction 2 shown in the figure. In each patch antenna unit, the plurality of elements may be electrically connected by wiring such as a strip line on a substrate. In each patch antenna unit, each of the plurality of elements is spaced apart at an interval d shorter than half the wavelength λ of the transmission wave. 2,s 8, each patch antenna unit may have any number of elements, two or more, electrically connected.

[0079] 8, the receiving antenna array 31 may be configured by arraying a plurality of patch antenna units in a direction 1 shown in the figure. The patch antenna units are spaced apart from each other by an interval d shorter than half the wavelength λ of the transmission wave. 1,s In one embodiment, the receive antenna array 31 may include any number of patch antenna units greater than or equal to two.

[0080] 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). The transmitting antenna array 24 and the receiving antenna array 31 may be arranged close to each other (monostatic). Furthermore, the direction 1 and the direction 2 shown in FIG. 8 may be geometrically orthogonal to each other.

[0081] The directivity of each of the transmitting antenna and the receiving antenna can be appropriately narrowed by the transmitting antenna array 24 and the receiving antenna array 31 as shown in FIG. 8. In addition, by using the transmitting antenna array 24 as shown in FIG. 8, the direction of transmission of each transmitting wave (transmitting signal) can be controlled at each timing of transmitting the transmitting wave, thereby realizing a beamformer for the direction 2 shown in FIG. 8. Furthermore, by using the receiving antenna array 31 as shown in FIG. 8, the arrival direction of the reflected wave can be estimated for the direction 1 shown in FIG. 8. In this way, it is possible to estimate the arrival direction of the reflected wave for two angles that are substantially orthogonal. Therefore, it is possible to obtain a point cloud showing an object such as the vibrating body 200 in three dimensions.

[0082] Next, a method for detecting the vibration of the vibrating body 200 by the electronic device 1 according to an embodiment will be described.

[0083] As described above, a millimeter wave radar sensor (millimeter wave sensor) can detect the vibration of an object by using the micro-Doppler phenomenon. A millimeter wave sensor can measure distance and / or angle. Therefore, the millimeter wave sensor can measure the average vibration displacement within a range (surface) included in a narrowed area for measuring distance and / or angle. However, it is not necessarily easy to measure the average vibration displacement within a predetermined range (surface) using a vibration sensor other than a millimeter wave sensor. Therefore, ingenuity is required to calibrate the millimeter wave sensor using another vibration sensor that has already been calibrated. If the millimeter wave sensor can be calibrated using another sensor that can detect vibration more accurately, the vibration of the vibrating body can be detected with good accuracy by transmitting and receiving millimeter waves. If the vibration of the vibrating body can be detected with good accuracy by transmitting and receiving waves such as millimeter waves, it is expected to be useful in a wide variety of fields.

[0084] Hereinafter, a mode in which the millimeter wave sensor is calibrated using another sensor capable of detecting vibrations more accurately will be described.

[0085] How, for example, the vibrating body 200 is detected on a 2D-FFT plane as a result of 2D-FFT (FIGS. 3 and 4) by a sensor based on millimeter wave radar technology such as the electronic device 1 according to one embodiment will be described.

[0086] FIG. 9 is a diagram showing an example of a 2D-FFT processing result when the vibrating body 200 is measured by the electronic device 1 according to an embodiment. The graph shown in FIG. 9 shows the entire result of the 2D-FFT processing executed by the signal processing unit 10 (the reception signal processing unit 12) of the electronic device 1 according to an embodiment. The horizontal axis of the graph shown in FIG. 9 indicates the distance (range), and the vertical axis indicates the velocity. The graph shown in FIG. 9 shows that in the range of distances from 0 to 6.3 m, the brighter the color, the stronger the signal strength. In the vicinity of the distance R1 shown in FIG. 9, a portion where a spectrum indicating the vibration of the vibrating body 200 exists is shown. The component of the spectrum shown in the vicinity of the distance R1 contains information on the vibration caused by the vibrating body 200.

[0087] In the 2D-FFT processed data shown in FIG. 9, the vibration data of the vibrating body 200 is filtered by extracting only the signals of range bins in the bright color area in the distance range of about 0 to 6.3 m, and the filtered data is called data S(Ω R [m],Ω D [n]). This data S(Ω R [m],Ω D By performing an inverse Fourier transform on the signal s(t [n]), an intermediate frequency signal (I / F signal) mainly including only the vibration of the vibrating body 200 is obtained. R ,t D ) can be obtained, where Ω R [m] and Ω D [n] indicates the range frequency and Doppler frequency on the 2D-FFT, respectively. R [l],t D[k] are the time sampling times of the I / F signal. Since these are all discrete values, the I / F signal is reconstructed by the discrete Fourier transform as shown in the following equation (1).

[0088]

number

[0089] From the I / F signal including the vibration of the vibrating body 200 obtained by the above formula (1), the vibration waveform is calculated as follows: First, as shown in the following formula (2), addition is performed in the range sampling direction of the I / F signal.

[0090]

number

[0091] Finally, the complex signal vector s sum By taking the argument on the Gaussian plane and multiplying it by a coefficient, we can obtain a time series vector of the vibration displacement, as shown in the following equation (3).

[0092]

number

[0093] Next, as an example, a model will be described in which the vibration of the vibrating body 200 configured as a loudspeaker is measured by the electronic device 1 configured as a millimeter wave sensor.

[0094] Fig. 10 is a diagram showing a model of an embodiment of an electronic device 1 measuring vibrations of a vibrating body 200. As shown in Fig. 10, the vibrating body 200 may be, for example, a loudspeaker. The electronic device 1 according to the embodiment may include a millimeter wave sensor.

[0095] 10, the electronic device 1 includes a transmitting antenna array 24 and a receiving antenna array 31. The transmission wave transmitted from the transmitting antenna array 24 reaches the vibrating body 200 after passing a distance R. At least a part of the transmission wave transmitted from the transmitting antenna array 24 becomes a reflected wave by being reflected by the vibrating body 200. The reflected wave reflected by the vibrating body 200 reaches the electronic device 1 after passing a distance R, and is received by the receiving antenna array 31. In this way, the electronic device 1 performs the above-mentioned processing on the vibrating body 200 by transmitting and receiving radio waves.

[0096] 10, the vibrating body 200 is shown in a schematic manner. In the vibrating body 200 shown in FIG. 10, a frame portion Γ constituting the outer frame of the loudspeaker 1 The vibrating body 200 is made of a highly rigid material such as metal. 2 The vibrating body 200 is bonded to the edge portion Γ of the loudspeaker using a dome made of a low elasticity material. 3 is a cone-type diaphragm Γ 2 and frame section Γ 1 Connect the edge part Γ 3 The cone-shaped diaphragm Γ is made of an elastic material. 2 is the frame part Γ 1 The cone-shaped diaphragm Γ is connected in a movable state to the 2 is electrically driven by a magnetic circuit consisting of a magnet, a yoke, a voice coil, etc.

[0097] As an example, the cone-type diaphragm Γ 2 The diaphragm 200 is made of a metal such as aluminum. With this configuration, the millimeter wave is completely reflected by the metal diaphragm surface. Therefore, in this configuration, the radar cross section (RCS) is simplified as the area of ​​the orthogonal projection of the entire diaphragm 200 as viewed from the antenna surface of the electronic device 1.

[0098] The I / F signal s(t R [l],tD [k]) is an I / F signal obtained by adding up all the reflected waves of the entire vibrating body 200 as seen from the electronic device 1, which is a millimeter wave sensor, and mixing them. Therefore, the vibration displacement in the above formula (3) is the average of the vibration of the entire surface of the vibrating body 200, as shown in the following formula (4).

[0099]

number

[0100] In the above formula (4), σ represents the area of ​​the orthogonal projection of the vibrating body 200 (loudspeaker) as viewed from the electronic device 1 (millimeter wave sensor). R represents the distance between the electronic device 1 and the vibrating body 200. Γ represents the entire area of ​​the vibrating body 200. Γ 1 indicates the frame part that can be considered vibrationally fixed. 2 indicates the cone-type diaphragm, which is the diaphragm of a loudspeaker. d vib (R) indicates the vibration displacement at the distance R from the electronic device 1.

[0101] The above formula (4) indicates that the vibration of the vibrating body 200 is caused by the frame portion Γ, which can be regarded as being vibrationally fixed. 1 The effect of the cone-type diaphragm Γ 2 The first term on the right-hand side of the above formula (4) represents the influence of both the vibrationally fixed frame part Γ 1 In this way, the vibrationally fixed frame part Γ 1 The contribution of is not necessary for the measurement of vibration displacement. 1 contributes as a bias to the constant or slow vibration displacement. 1 It is desirable to exclude the contribution of

[0102] Frame section Γ 1 It is difficult to eliminate the influence of the contribution of by ordinary millimeter wave radar signal processing, i.e., 2D-FFT processing, CFAR processing, range bin filtering, etc. For this reason, the influence of the contribution of the frame part Γ1 The influence of the contribution of the vibration waveform time series vector D vib It may be possible to remove the millimeter wave from the electronic device 1 by frequency filtering or the like. However, even if such filtering is performed, it is difficult to completely remove the influence on the vibration displacement. It is also expected that perturbation of the vibration displacement due to other influences may be added. Therefore, when the electronic device 1 according to the embodiment is configured to include a millimeter wave sensor, the millimeter wave sensor needs to be calibrated by a reference measuring instrument.

[0103] Next, a problem that arises when calibrating the electronic device 1 that includes a millimeter wave sensor will be described.

[0104] FIG. 11A is a graph showing a waveform of vibration displacement of a loudspeaker at 750 Hz measured by a millimeter wave sensor (electronic device 1). FIG. 11B is a graph showing a waveform of vibration displacement of the same loudspeaker at 750 Hz measured by a laser Doppler vibrometer (LDV). Both FIG. 11A and FIG. 11B show an example in which a voltage with a frequency of 750 Hz is applied to the loudspeaker and the voltage is increased in steps. In both FIG. 11A and FIG. 11B, the horizontal axis represents elapsed time and the vertical axis represents vibration displacement. The LDV measures the vibration of a point (e.g., the center point on the dust cap of the loudspeaker) where the laser is irradiated. In contrast, the millimeter wave sensor measures the average value of the vibration displacement by measuring the entire vibration surface. 11A and 11B, there is a difference of about 10 to 20% between the measured values ​​of both (the measurement result by the millimeter wave sensor is about 10 to 20% smaller). Therefore, it is difficult to calibrate the millimeter wave sensor itself by simply comparing the measurement result of vibration at one point by the LDV and the measurement result by the millimeter wave sensor.

[0105] Therefore, in order to calibrate a Doppler radar such as a millimeter wave sensor, the electronic device 1 according to an embodiment executes the following two stages of measurement and signal processing. A. Measurement of vibration of the reference oscillator B. Calibration of Electronic Device 1 (Millimeter Wave Sensor) Using a Reference Vibration Body The electronic device 1 according to one embodiment measures the vibration of the vibrating body using a high-frequency (20 GHz or higher) Doppler radar in the millimeter wave band or higher that performs distance measurement (ranging), angle estimation (angle measurement), and Doppler velocity detection using electromagnetic waves or sound waves. According to the electronic device 1 according to one embodiment, when measuring the vibration of the vibrating body using the Doppler radar as described above, the absolute value of the vibration amplitude can be calibrated. The electronic device 1 according to one embodiment can accurately measure the vibration amplitude of the vibrating body using the millimeter wave sensor by calibrating the millimeter wave sensor.

[0106] Hereinafter, each of the above-mentioned "A. Measurement of vibration of the reference oscillator" and "B. Calibration of the electronic device 1 (millimeter wave sensor) using the reference oscillator" will be further explained.

[0107] (A. Measurement of vibration of the reference oscillator) Here, an electromechanical acoustic transducer capable of generating vibrations from several tens of Hz to 10 kHz or more, such as a loudspeaker, is used as the reference vibrator. The millimeter wave sensor detects the average vibration displacement by integrating all vibration components within the range irradiated by the radio waves (Field of View (hereinafter referred to as FOV)). For this reason, here, it is necessary to obtain the average vibration displacement of the entire vibration surface for the electrical signal of the reference vibrator.

[0108] In order to obtain the average vibration displacement of the reference oscillator, it is possible to use an LDV to perform measurements in one of the following ways: (1) Vibration measurements are taken at one point on the reference vibration body, and the vibration amplitude at the measurement point and the frequency response of the average displacement are obtained using numerical analysis techniques such as the finite element method. (2) Scanning the entire vibration surface of the reference vibration body

[0109] Below, we will focus on the above (1), which is expected to be more realistically implemented.

[0110] In (1) above, it is important to know what frequency characteristics the ratio of the vibration displacement at the center (center of the dust cap) of a loudspeaker (diaphragm diameter about 10 cm) as shown in Figure 10 to the overall average vibration displacement has. There is no common method for measuring the vibration of the entire surface of a vibrating body such as a reference vibrator. For this reason, it is necessary to obtain the ratio of the vibration displacement to the overall average vibration displacement by performing a detailed analysis of the characteristics of the vibrating body using numerical analysis, etc.

[0111] The ratio of the vibration displacement at the center of the loudspeaker (center of the dust cap) to the average vibration displacement of the whole loudspeaker, r(f i ) is formulated as shown in the following equation (5).

[0112]

number

[0113] In the above formula (5), d calc,point (f i ) indicates the displacement frequency response of the center point of the reference body. d calc,mean (f i ) indicates the average vibration displacement of the entire vibration plane of the reference vibration body. i denotes the i-th discrete frequency.

[0114] FIG. 12 shows the r(f i 12 is a graph showing an example of the result of calculating the ratio of the vibration displacement at the center position of a loudspeaker, which is a reference vibration body, to the average vibration displacement, using the finite element method. The horizontal axis of FIG. 12 shows the frequency, and the vertical axis shows the displacement ratio.

[0115] The dashed line in Fig. 12 shows the relationship between r(f i ) is shown. In an ideal piston diaphragm, the vibration displacement at a certain point and the average vibration are exactly the same. Therefore, in an ideal piston diaphragm, it is natural that r(f i) is 1. In other words, in an ideal piston diaphragm, even if the vibration frequency changes, the average value over the entire surface does not change. Therefore, in an ideal piston diaphragm, r(f i ) can be said to have no frequency dependence.

[0116] On the other hand, the solid line in Fig. 12 shows the r(f i ) for loudspeakers. i ) has a frequency characteristic centered around 1. That is, in a loudspeaker, r(f i ) is frequency dependent.

[0117] Next, we will discuss the relationship between the size of the reference oscillator and the FOV, which is determined by the directivity of the transmission and reception of waves.

[0118] FIG. 13 is a diagram showing an example of the relationship between the size of the reference vibrator and the FOV determined by the directivity of the transmission and reception of the wave. As shown in FIG. 13, the vibrator 200 is a reference vibrator, which is a loudspeaker in this case. In FIG. 13, the FOV is a range determined by the direction estimation process already described as the directivity of the transmission and reception of the wave and the reception signal processing. That is, the vibration within the range of the FOV is set so that it can be measured by the millimeter wave sensor. As shown in FIG. 13, by setting the FOV to include the entire reference vibrator, all the vibrations of the reference vibrator are added up.

[0119] Next, an operation for generating data of the average vibration displacement of the reference vibration body for use in the electronic device 1 according to an embodiment will be described. Fig. 14 is a flowchart for explaining the generation of data of the average vibration displacement of the reference vibration body serving as a reference.

[0120] First, in step S11, one point on the reference oscillator is measured using an LDV or the like. In step S11, the frequency characteristic d of the vibration displacement at one measurement point is obtained by measurement using the LDV or the like. ref,meas, (f i ) can be obtained.

[0121] Next, in step S12, it is determined whether or not the frequency i has reached the frequency point number I. If the frequency i has not reached the frequency point number I, the operation of step S11 is repeated to measure a plurality of frequencies. On the other hand, if the frequency i has reached the frequency point number I, the operation of step S13 may be proceeded to. That is, in FIG. 14, the operation loop of step S11 is a loop in which the measurement of one point on the reference vibrator by an LDV or the like is performed for a frequency f i This indicates that this should be done every time.

[0122] Next, in step S13, as described above, r(f i ) is obtained. As mentioned above, r(f i ) is the displacement frequency response of the center point of the reference body d calc,point (f i ) and the average vibration displacement d of the reference vibration body on the entire vibration plane calc,mean (f i ) (see formula (5) above).

[0123] Next, in step S14, d ref,meas, (f i ) and r(f i ) based on the above, a reference value of the average vibration displacement of the reference vibration body is calculated according to the following equation (6).

[0124]

number

[0125] d shown in the above formula (6) ref (f i ) is the data of the average vibration displacement of the reference vibration body obtained by the flowchart shown in FIG.

[0126] (B. Calibration of Electronic Device 1 (Millimeter Wave Sensor) Using a Reference Vibration Body) Next, an operation of calibrating the electronic device 1 (millimeter wave sensor) using the reference vibrator will be described. Here, the electronic device 1 (millimeter wave sensor) according to an embodiment is calibrated by taking into consideration the frequency characteristics of the average vibration displacement of the entire vibration surface with respect to the measured electrical signal of the reference vibrator.

[0127] Fig. 15 is a flowchart for explaining the operation executed by the electronic device 1 according to an embodiment. For example, Fig. 15 may be a flowchart showing the operation when calibrating each millimeter wave sensor unit. Fig. 15 shows the data d ref (f i ) may be used as a flowchart for calibrating each individual millimeter wave sensor.

[0128] When the operation shown in FIG. 5 starts, in step S21, the signal processing unit 10 of the electronic device 1 according to an embodiment may calculate and store a calibration coefficient (ratio) between the measurement value of the reference vibrator by the electronic device 1 and the reference value. In step S21, the signal processing unit 10 may calculate and store the calibration coefficient (ratio) by comparing the measurement value of the reference vibrator by the electronic device 1 with the reference value. In step S21, the signal processing unit 10 calculates and stores the calibration coefficient (ratio) c calib (f i ) can be calculated as follows:

[0129]

number

[0130] Here, the frequency response d of the vibration amplitude measured by electronic device 1 (mm wave sensor) mmwave (f i ) is the time waveform q of the vibration amplitude measured by electronic device 1 (millimeter wave sensor). mmwave (t i ) can be obtained by Fourier transform.

[0131] Next, in step S22, it is determined whether or not the frequency i has reached the number of frequency points I. If the frequency i has not reached the number of frequency points I, the operation of step S21 is repeated to calculate calibration coefficients for a plurality of frequencies. On the other hand, if the frequency i has reached the number of frequency points I, the operation shown in FIG. 15 may be ended. That is, in FIG. 15, the loop of the operation of step S21 is ref (f i ) to calculate the calibration coefficient for each frequency.

[0132] The calibration coefficient (correction value) c obtained by the operation shown in Figure 15 calib (f i ) is a coefficient on the frequency axis. Therefore, the time waveform q of the vibration amplitude of the calibrated electronic device 1 (millimeter wave sensor) mmwave,calib (t i ) can be obtained as follows: In equation (8), F -1 [ ] denotes the inverse Fourier transform.

[0133]

number

[0134] The calibration coefficient (correction value) c obtained from FIG. 15 and the above formula (7) calib (f i ) may be stored in any memory of each electronic device 1 (each millimeter wave sensor system). As a result, each electronic device 1 (each millimeter wave sensor system) is automatically calibrated every time a measurement is performed. The correction process by the electronic device 1 according to the embodiment described above may be performed by, for example, the correction processing unit 13 in the signal processing unit 10 shown in FIG. 2 calculating the above formula (8).

[0135] Next, a result of performing calibration by the electronic device 1 according to an embodiment will be described. Fig. 16 is a graph showing an example of a result of performing calibration by the electronic device 1 according to an embodiment. In Fig. 16, the horizontal axis indicates frequency, and the vertical axis indicates vibration displacement.

[0136] 16 is a plot of frequency characteristics of the average value of the vibration displacement over the entire surface of a vibrating body that is a loudspeaker, with the voltage value fixed. In one embodiment, the vibration displacement value output by the electronic device 1 (millimeter wave sensor) may be calibrated by acquiring a calibration value of the response of the electronic device 1 (millimeter wave sensor) for a reference vibrating body that serves as a reference.

[0137] The solid line in Fig. 16 indicates the average value of vibration displacement calculated using a reference device (LDV) for the standard vibration body. The plots with asterisks (*) in Fig. 16 indicate raw data (before calibration) of the measurement results by electronic device 1 (millimeter wave sensor). The plots with circles (◯) in Fig. 16 indicate the results of performing calibration on the raw data of the measurement results by electronic device 1 (millimeter wave sensor). As shown in Fig. 16, the data after calibration (◯) is approaching the reference graph (solid line), which shows that the calibration has been performed appropriately.

[0138] As described above, the control method of the electronic device 1 measures the vibration of the object (vibration body 200) based on the electromagnetic waves reflected from the object, using the calibration information stored in the storage unit (calibration coefficient memory 14). The control method of the electronic device 1 includes a calibration step of calibrating the measurement result of the electronic device 1 based on the result of measuring the vibration of the reference vibration body.

[0139] In the above-mentioned calibration step, the measurement result of the electronic device 1 may be calibrated based on the result of measuring the vibration of the reference oscillator by another vibrometer (eg, LDV) different from the electronic device 1.

[0140] The above-mentioned calibration steps include: a first calculation step of calculating, by numerical analysis, a ratio of a displacement frequency response of a specific point of the reference vibration body to a position average frequency response averaged over the position of the displacement frequency response; A measurement step of measuring a specific point vibration, which is a vibration of a specific measurement point of the reference vibration body, using a reference inspection device (e.g., an LDV, etc.); A second calculation step of calculating a reference of an average vibration displacement of the reference vibration body based on the above ratio and the above specific point vibration; may include:

[0141] The above-mentioned calibration steps include: The measurement results of the electronic device 1 may be calibrated based on the average vibration displacement reference and the specific displacement frequency response of the reference vibration body measured by the electronic device 1.

[0142] The above-described embodiment may be implemented as a program executed by an electronic device that measures vibration of an object based on electromagnetic waves reflected from the object using calibration information stored in a storage unit. In this case, the program may execute a calibration step of calibrating the measurement result of the electronic device based on the result of measuring the vibration of the reference oscillator.

[0143] The above-described embodiment may be implemented as an electronic device 1 according to an embodiment. In this case, the electronic device 1 may include a signal processing unit 10 and a correction processing unit 13. The signal processing unit 10 measures the vibration of an object based on electromagnetic waves reflected from the object, using calibration information stored in a storage unit (calibration coefficient memory 14). The correction processing unit 13 calibrates the measurement result of the electronic device 1 based on the result of measuring the vibration of the reference oscillator.

[0144] According to the electronic device 1 and the calibration method for the electronic device 1 of the embodiment, the millimeter wave sensor can be calibrated by another sensor capable of detecting vibrations more accurately. Therefore, according to the electronic device 1 and the calibration method for the electronic device 1 of the embodiment, the vibration of the vibrating body can be detected with good accuracy by transmitting and receiving waves such as millimeter waves. Therefore, the electronic device 1 and the calibration method for the electronic device 1 of the embodiment can be expected to be useful in a wide variety of fields.

[0145] (Other embodiments) Other embodiments will be described below.

[0146] 10, an example of measuring vibrations using the vibrating body 200, which is an electrodynamic loudspeaker, as the reference vibrating body has been described. However, in one embodiment, the vibrating body 200 used as the reference vibrating body may be a piezoelectric or electrostatic loudspeaker, or a vibrating body based on another principle may be used.

[0147] In the above-described embodiment, the reference vibrometer is an LDV, but in one embodiment, the reference vibrometer may be, for example, a contact-type acceleration sensor.

[0148] 14 and 15 have been described assuming that the data of each frequency is changed in discrete steps, however, in one embodiment, processing and measurement may be performed by performing a frequency sweep to change the frequency continuously.

[0149] 10, an example has been described in which vibration is measured using the vibrating body 200, which is an electrodynamic loudspeaker, as the reference vibrating body. However, in one embodiment, a vibrating body formed of a piezoelectric element and a metal plate may be used as the reference vibrating body.

[0150] FIG. 17 is a diagram showing a schematic appearance of a vibrating body composed of a piezoelectric element and a metal plate. As shown in FIG. 17, the vibrating body 300 may include a piezoelectric element 310. As shown in FIG. 17, the vibrating body 300 may include fixed ends 320 at both ends to form a beam supported at both ends. FIG. 18 is a diagram showing the state of vibration amplitude (vibration displacement) of the vibrating body 300 at 710 Hz. As a vibrating body serving as a reference vibrating body that can be used in an embodiment, for example, a vibrating body having a cantilever structure or a support structure at both ends may be used. As a vibrating body serving as a reference vibrating body that can be used in an embodiment, for example, a vibrating body made of a piezoelectric element and a metal such as aluminum, plastic, ceramic, wood, or other material, or a combination of these materials may be used. As a resonant frequency of a vibrating body serving as a reference vibrating body that can be used in an embodiment, one having a first resonant frequency and a second resonant frequency can be used. In the present disclosure, the resonant frequency of a vibrating body serving as a reference vibrating body that can be used in an embodiment may have a third or higher resonant frequency.

[0151] The calibration method according to an embodiment can be used, for example, in the manufacturing process of the electronic device 1 (millimeter wave sensor). The calibration method according to an embodiment can be applied, for example, in the manufacturing process of the electronic device 1 (millimeter wave sensor), after manufacturing the substrate of the millimeter wave sensor (such as an antenna substrate or an electronic circuit with an LSI mounted thereon) or after the final assembly of the millimeter wave sensor is completed. In this case, in one embodiment, the calibration coefficient (correction value) c calib (f i ) may be written to a non-volatile memory in the electronic device 1 (millimeter wave sensor) and / or an external device 60 ( FIG. 2 ) to which the electronic device 1 (millimeter wave sensor) is connected. The electronic device 1 or the control method for the electronic device 1 according to an embodiment may be implemented as a manufacturing method for the electronic device 1 in which the above-mentioned calibration method is incorporated into, for example, the production process.

[0152] Although the present disclosure has been described based on the drawings and examples, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. Therefore, it should be noted that these modifications or corrections are included in the scope of the present disclosure. For example, the functions included in each functional unit can be rearranged so as not to be logically inconsistent. Multiple functional units, etc. may be combined into one or divided. Each embodiment of the present disclosure described above is not limited to being implemented faithfully to each of the embodiments described, and may be implemented by combining each feature as appropriate or omitting a part. In other words, the contents of the present disclosure can be modified and corrected in various ways by a person skilled in the art based on the present disclosure. Therefore, these modifications and corrections are included in the scope of the present disclosure. For example, in each embodiment, each functional unit, each means, each step, etc. can be added to other embodiments so as not to be logically inconsistent, or replaced with each functional unit, each means, each step, etc. of other embodiments. In addition, in each embodiment, multiple functional units, each means, each step, etc. can be combined into one or divided. Furthermore, each of the above-described embodiments of the present disclosure is not limited to being implemented faithfully according to each of the described embodiments, but may be implemented by combining each feature or omitting some features as appropriate.

[0153] The above-described embodiment is not limited to being implemented only as the electronic device 1. For example, the above-described embodiment may be implemented as a control method for an apparatus such as the electronic device 1. Furthermore, the above-described embodiment may be implemented as a program executed by an apparatus such as the electronic device 1, or as a storage medium or recording medium on which a program is recorded.

[0154] Moreover, the electronic device 1 according to the above-mentioned embodiment has been described as including components constituting a so-called radar sensor, such as the transmitting antenna array 24 and the receiving antenna array 31. However, the electronic device according to one embodiment may be implemented as, for example, a configuration such as a signal processing unit 10. In this case, the signal processing unit 10 may be implemented as having a function of processing signals handled by, for example, the transmitting antenna array 24 and the receiving antenna array 31. [Explanation of symbols]

[0155] 1 Electronic equipment 10 Signal Processing Section 11 Signal generation processing section 12 Receiving signal processing section 13 Correction processing section 14 Calibration coefficient (correction value) memory 14 Waveform analysis processing section 21 Transmit DAC 22 Transmitting circuit 23 Millimeter wave transmission circuit 24 Transmitting Antenna Array 31 Receiving Antenna Array 32 Mixer 33 Receiving circuit 34 Receive ADC 50 Communication Interface 60 External equipment

Claims

1. A method for controlling an electronic device that measures vibration of an object based on electromagnetic waves reflected from the object by using calibration information stored in a storage unit, comprising: A method for controlling an electronic device, comprising: a calibration step of calibrating a measurement result of the electronic device based on a result of measuring vibration of a reference oscillator.

2. 2. The control method according to claim 1, wherein the calibration step calibrates the measurement result of the electronic device based on a result of measuring the vibration of the reference vibration body by a vibrometer other than the electronic device.

3. The calibration step includes: a first calculation step of calculating, by numerical analysis, a ratio of a displacement frequency response of a specific point of the reference vibration body to a position average frequency response averaged over the position of the displacement frequency response; a measurement step of measuring a specific point vibration, which is a vibration of a specific measurement point of the reference vibration body, by using a reference inspection device; A second calculation step of calculating a reference of an average vibration displacement of the reference vibration body based on the ratio and the specific point vibration; The control method of claim 1 , comprising:

4. The calibration step includes: The control method according to claim 2 , further comprising the step of calibrating the measurement result of the electronic device based on the average vibration displacement reference and the specific displacement frequency response of the reference vibrator measured by the electronic device.

5. An electronic device that measures vibration of an object based on electromagnetic waves reflected from the object by using calibration information stored in a storage unit, A program that causes a calibration step to be executed in which a measurement result of the electronic device is calibrated based on a result of measuring the vibration of a reference oscillator.

6. a signal processing unit that measures vibration of an object based on electromagnetic waves reflected from the object by using calibration information stored in a storage unit; A correction processing unit that calibrates a measurement result of the electronic device based on a result of measuring the vibration of the reference oscillator; An electronic device comprising:

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