This application claims priority from Japanese Patent Application No. 2020-197127 filed in Japan on Nov. 27, 2020, the entire disclosure of which is incorporated herein by reference.
The present disclosure relates to an electronic device, a method for controlling an electronic device, and a program.
For example, in fields such as automobile-related industries, a technology for measuring a distance or the like between a vehicle of interest and a predetermined object is regarded as important. Recently, various studies have been conducted particularly on a radar (Radio Detecting and Ranging) technology for measuring a distance or the like to an object such as an obstacle by transmitting a radio wave such as a millimeter wave and then receiving a reflected wave reflected off the object. Such a technology for measuring a distance or the like expectedly becomes more important in the future with progresses of a technology for assisting drivers in driving and an automated-driving-related technology for partially or entirely automating driving.
Various suggestions have been made on a technology for detecting the presence of an object by receiving a reflected wave of a radio wave that has been transmitted and reflected off the object. For example, studies have been conducted on a technology for detecting an object in a relatively wide range by a sensor transmitting a transmission wave and then receiving a reflected wave that arrives not only from a front direction of the sensor but also from a wider angle range. For example, Patent Literature 1 has suggested a radar device that detects an azimuth in a wide angle range.
In one embodiment, an electronic device includes a first sensor and a second sensor.
Each of the first sensor and the second sensor includes a transmission antenna, a reception antenna, and a controller.
The transmission antenna transmits a transmission wave.
The reception antenna receives a reflected wave that is the transmission wave having been reflected.
The controller detects an object that reflects the transmission wave, based on a transmission signal transmitted as the transmission wave and a reception signal received as the reflected wave.
The first sensor and the second sensor are disposed in respective directions that form a predetermined angle with respect to each other.
In one embodiment, a method for controlling an electronic device is a method for controlling an electronic device including a first sensor and a second sensor disposed in respective directions that are not parallel to each other.
The method includes
In one embodiment, a program causes
A technology for detecting an object by receiving a reflected wave that is a transmitted transmission wave reflected off the object desirably enables object detection with a good accuracy in a wide range. The present disclosure provides an electronic device, a method for controlling an electronic device, and a program that enable object detection with a good accuracy in a wide range. One embodiment can provide an electronic device, a method for controlling an electronic device, and a program that enable object detection with a good accuracy in a wide range. One embodiment is described in detail below with reference to the drawings.
An electronic device according to one embodiment is mounted in a vehicle (mobility device) such as an automobile, for example, and is capable of detecting, as a target, a predetermined object located around the mobility device. To this end, the electronic device according to the one embodiment is capable of transmitting a transmission wave to an area around the mobility device from a transmission antenna installed on or in the mobility device. The electronic device according to the one embodiment is also capable of receiving a reflected wave that is the reflected transmission wave, from a reception antenna installed on or in the mobility device. For example, a radar sensor or the like installed on or in the mobility device may include at least one of the transmission antenna or the reception antenna.
A typical configuration example is described below in which the electronic device according to the one embodiment is mounted in an automobile such as a passenger car. However, the mobility device in which the electronic device according to the one embodiment is mounted is not limited to an automobile. The electronic device according to the one embodiment may be mounted in various mobility devices such as an autonomous car, a bus, a truck, a taxi, a motorcycle, a bicycle, a ship, an aircraft, a helicopter, agricultural machinery such as a tractor, a snowplow, a garbage truck, a police car, an ambulance, and a drone. The mobility device in which the electronic device according to the one embodiment is mounted is not necessarily limited to a mobility device that moves by its own motive power. For example, the mobility device in which the electronic device according to the one embodiment is mounted may be a trailer towed by a tractor. The electronic device according to the one embodiment is capable of measuring a distance or the like between a sensor and a predetermined object when at least one of the sensor or the object is movable. The electronic device according to the one embodiment is also capable of measuring a distance or the like between the sensor and the object even when both the sensor and the object are stationary. The automobile encompassed by the present disclosure is not limited by the overall length, the overall width, the overall height, the displacement, the seating capacity, the load, or the like. For example, the automobiles of the present disclosure include an automobile having a displacement greater than 660 cc and an automobile having a displacement equal to or less than 660 cc that is a so-called light automobile. The automobiles encompassed by the present disclosure also include an automobile that partially or entirely uses electricity as energy and uses a motor.
An example of how the sensor included in the electronic device according to the one embodiment detects an object is described.
A mobility device 100 illustrated in
The sensor 5 including the transmission antenna is installed on the mobility device 100 illustrated in
The sensor 5 transmits an electromagnetic wave as a transmission wave from the transmission antenna. For example, when a predetermined object (for example, an object 200 illustrated in
The sensor 5 including the transmission antenna may be typically a radar (Radio Detecting and Ranging) sensor that transmits and receives a radio wave. However, the sensor 5 is not limited to a radar sensor. The sensor 5 according to the one embodiment may be, for example, a sensor based on the LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) technology that uses an optical wave. Since the technologies such as the radar and the LIDAR are already known, detailed description may be appropriately simplified or omitted.
The electronic device 1 mounted in the mobility device 100 illustrated in
The object 200 may be, for example, at least any of an oncoming automobile traveling in a lane adjacent to a lane of the mobility device 100, an automobile traveling next to the mobility device 100, an automobile traveling in front of or behind the mobility device 100 in the same lane, and the like. The object 200 may also be any object located around the mobility device 100, such as a motorcycle, a bicycle, a stroller, a person such as a pedestrian, an animal, other forms of life such as an insect, a guardrail, a median strip, a road sign, a step on a sidewalk, a wall, a maintenance hole, or an obstacle. The object 200 may be in motion or stationary. For example, the object 200 may be an automobile or the like that is parked or stationary around the mobility device 100. In the present disclosure, the object detected by the sensor 5 includes a living thing such as a person or an animal in addition to a non-living thing. The object detected by the sensor 5 in the present disclosure includes a target, which includes a person, an object, and an animal, to be detected with the radar technology.
In
A typical example is described below in which the transmission antenna of the sensor 5 transmits a radio wave in a frequency band, such as a millimeter wave (equal to or higher than 30 GHz) or a quasi-millimeter wave (for example, around 20 GHz to 30 GHz). For example, the transmission antenna of the sensor 5 may transmit a radio wave having a frequency bandwidth of 4 GHz such as from 77 GHz to 81 GHz. For example, the transmission antenna of the sensor 5 may transmit a radio wave having a frequency bandwidth from 57 GHz to 64 GHz, from 76 GHz to 77 GHz, from 134 GHz to 141 GHz, or the like.
As described later, the sensor 5 includes a transmission antenna that transmits a transmission wave, and a reception antenna that receives a reflected wave. As described later, the sensor 5 may include multiple transmission antennas and multiple reception antennas (for example, a patch antenna). As illustrated in
As illustrated in
As illustrated in
The cover member 60 may be made of, for example, a resin. The cover member 60 may be made of a material through which a transmission wave transmitted by the electronic device 1 and a reflected wave received by the electronic device 1 pass. The cover member 60 may be made of a material having a predetermined dielectric constant. The cover member 60 may constitute a housing of the electronic device 1 or may constitute a radome of the electronic device 1.
The electronic device 1 illustrated in
The sensor 5 may be a quadrilateral plate-like member as illustrated in
As illustrated in
As illustrated in
For example, supports 66a and 66c may support the first sensor 5a. Likewise, for example, supports 66b and 66c may support the second sensor 5b. Each of the supports 66a, 66b, and 66c may be made of a material that is rigid enough to support the first sensor 5a and the second sensor 5b, such as a resin or a metal, for example. When the height of the support 66a (dimension in the Y-axis direction) is set different from the height of the support 66c (dimension in the Y-axis direction), the first sensor 5a is supported with inclined at a predetermined angle with respect to the cover bottom surface portion 62. Likewise, when the height of the support 66b (dimension in the Y-axis direction) is set different from the height of the support 66c (dimension in the Y-axis direction), the second sensor 5b is supported with inclined at a predetermined angle with respect to the cover bottom surface portion 62. When the height of the support 66a (dimension in the Y-axis direction) is set equal to the height of the support 66b (dimension in the Y-axis direction), the first sensor 5a and the second sensor 5b are symmetrically supported with inclined at the same angle.
The configuration has been described in which the supports 66a, 66b, and 66c support the first sensor 5a and the second sensor 5b. The configuration of the electronic device 1 according to the one embodiment is not limited to such a configuration. For example, a support plate 68a may support the first sensor 5a inside the cover member 60. In this case, the supports 66a and 66c may support the support plate 68a. Likewise, a support plate 68b may support the second sensor 5b inside the cover member 60. In this case, the supports 66b and 66c may support the support plate 68b.
As illustrated in
In
As illustrated in
As illustrated in
A range in which the electronic device 1 according to the one embodiment can detect an object is described.
As illustrated in
As illustrated in
As described above, in the electronic device 1 according to the one embodiment, the angle at which an object that reflects the transmission wave T is detectable may be made larger than 1800 by the first sensor 5a and the second sensor 5b. The electronic device 1 according to the one embodiment can avoid a decrease in the object detection accuracy in a wide angle range in which the angle exceeds 180°. Thus, the electronic device 1 according to the one embodiment can detect an object with a good accuracy in a wide range. The electronic device 1 according to the one embodiment expectedly reduces a blind spot in object detection even if an installation position or the like is restricted when the electronic device 1 is installed in a mobility device, for example.
When the electronic device 1 including the first sensor 5a and the second sensor 5b illustrated in
For example, when the first sensor 5a and the second sensor 5b transmit radio waves having the same frequency, the electronic device 1 may control a direction of a beam of the transmission waves of at least one of the first sensor 5a and the second sensor 5b such that the overlapping portion of the ranges Ta and Tb narrows or is no longer exist. When the first sensor 5a and the second sensor 5b transmit radio waves toward the overlapping portion of the ranges Ta and Tb, the transmission waves may have different frequencies. This configuration allows detection results obtained by the first sensor 5a and the second sensor 5b to be superimposed in the overlapping portion of the ranges Ta and Tb. When the first sensor 5a and the second sensor 5b transmit radio waves toward the overlapping portion of the ranges Ta and Tb, the first sensor 5a and the second sensor 5b may transmit the radio waves such that the radio waves do not overlap spatially (in the Z-axis direction illustrated in
The electronic device 1 according to the one embodiment is further described in view of functions and/or operations.
As illustrated in
For example, as illustrated in
As described above, the first sensor 5a may control transmission of a transmission wave performed by the second sensor 5b in the electronic device 1 according to the one embodiment. The first sensor 5a may control a transmission timing of a transmission wave transmitted by the second sensor 5b in the electronic device 1 according to the one embodiment. The first sensor 5a may perform control for making the frequency of a transmission wave transmitted by the first sensor 5a and the frequency of a transmission wave transmitted by the second sensor 5b different from each other in the electronic device 1 according to the one embodiment. The first sensor 5a and the second sensor 5b may be controlled independently of each other in the electronic device 1 according to the one embodiment.
As illustrated in
The configuration of each of the first sensor 5a and the second sensor 5b is described in detail.
As described above, the first sensor 5a may include the transmission control unit 28 illustrated in
When a distance or the like is measured by using a millimeter-wave radar, a frequency-modulated continuous wave radar (hereinafter, referred to as an FMCW radar) is often used. The FMCW radar sweeps a frequency of a to-be-transmitted radio wave to generate a transmission signal. Thus, a frequency of the radio wave used by such a millimeter-wave FMCW radar, which uses a radio wave of a frequency band of 79 GHz, for example, has a frequency bandwidth of 4 GHz such as from 77 GHz to 81 GHz, for example. The radar of the frequency band of 79 GHz has a feature that a usable frequency bandwidth is wider than other millimeter-wave and/or quasi-millimeter-wave radars of frequency bands of 24 GHz, 60 GHz, and 76 GHz, for example. Such an embodiment is described below as an example.
As illustrated in
The controller 10 may include a distance FFT processing unit 11, a velocity FFT processing unit 12, a distance-velocity detection determining unit 13, an angle-of-arrival estimating unit 14, and an object detecting unit 15. These functional units included in the controller 10 are further described later.
As illustrated in
As illustrated in
The controller 10 included in the sensor 5 according to the one embodiment is capable of controlling the individual functional units of the sensor 5 and controlling operations of the entire sensor 5. To provide control and processing capabilities for executing various functions, the controller 10 may include at least one processor, for example, a CPU (Central Processing Unit) or a DSP (Digital Signal Processor). The controller 10 may be collectively implemented by one processor, may be implemented by some processors, or may be implemented by discrete individual processors. The processor may be implemented as one integrated circuit. The integrated circuit is also referred to as an IC. The processor may be implemented as multiple integrated circuits and discrete circuits connected to be able to perform communication. The processor may be implemented based on various other known technologies. In the one embodiment, the controller 10 may be configured as, for example, a CPU and a program executed by the CPU. The controller 10 may appropriately include a memory necessary for operations of the controller 10.
The storage unit 40 may store a program executed by the controller 10, results of processing performed by the controller 10, and so on. The storage unit 40 may function as a work memory of the controller 10. The storage unit 40 may include, for example, a semiconductor memory or a magnetic disk. However, the storage unit 40 is not limited to these, and can be any storage device. The storage unit 40 may be, for example, a storage medium such as a memory card inserted to the electronic device 1 according to the present embodiment. The storage unit 40 may be an internal memory of the CPU used as the controller 10 as described above.
In the one embodiment, the storage unit 40 may store various parameters for setting a range in which an object is detected based on a transmission wave T transmitted from each transmission antenna 25 and a reflected wave R received from each reception antenna 31.
In the sensor 5 according to the one embodiment, the controller 10 is capable of controlling at least one of the transmission unit 20 or the reception units 30. In this case, the controller 10 may control at least one of the transmission unit 20 or the reception units 30, based on various kinds of information stored in the storage unit 40. In the sensor 5 according to the one embodiment, the controller 10 may instruct the signal generating unit 21 to generate a signal or may control the signal generating unit 21 to generate a signal.
In accordance with control performed by the transmission control unit 28, the signal generating unit 21 generates a signal (transmission signal) to be transmitted as a transmission wave T from each of the transmission antennas 25. When generating a transmission signal, the signal generating unit 21 may allocate a frequency of the transmission signal in accordance with control performed by the transmission control unit 28, for example. Specifically, the signal generating unit 21 may allocate the frequency of the transmission signal in accordance with a parameter set by the transmission control unit 28, for example. For example, the signal generating unit 21 receives frequency information from the transmission control unit 28 or the storage unit 40 and generates a signal having a predetermined frequency in a frequency band such as from 77 GHz to 81 GHz, for example. The signal generating unit 21 may include a functional unit such as a voltage control oscillator (VCO), for example.
The signal generating unit 21 and/or the transmission control unit 28 may be configured as hardware having the function, for example as a microcomputer, or for example as a processor such as a CPU and a program or the like executed by the processor. Each functional unit described below may also be configured as hardware having the function, for example as a microcomputer if possible, or for example as a processor such as a CPU and a program or the like executed by the processor if possible.
In the sensor 5 according to the one embodiment, the signal generating unit 21 may generate a transmission signal (transmission chirp signal) such as a chirp signal, for example. In particular, the signal generating unit 21 may generate a signal (linear chirp signal) whose frequency changes linearly and periodically. For example, the signal generating unit 21 may generate a chirp signal whose frequency linearly and periodically increases from 77 GHz to 81 GHz as time elapses. For example, the signal generating unit 21 may generate a signal whose frequency periodically repeats a linear increase (up-chirp) from 77 GHz to 81 GHz and a decrease (down-chirp) as time elapses. For example, the controller 10 may set in advance the signal generated by the signal generating unit 21. For example, the storage unit 40 or the like may store in advance the signal generated by the signal generating unit 21. Since a chirp signal used in a technical field such as the radar is known, more detailed description is appropriately simplified or omitted. The signal generated by the signal generating unit 21 is supplied to the synthesizer 22.
The synthesizer 22 increases the frequency of the signal generated by the signal generating unit 21 to a frequency in a predetermined frequency band. The synthesizer 22 may increase the frequency of the signal generated by the signal generating unit 21 to a frequency selected as a frequency of the transmission wave T to be transmitted from each of the transmission antennas 25. For example, the controller 10 may set the frequency selected as the frequency of the transmission wave T to be transmitted from each of the transmission antennas 25. For example, the storage unit 40 may store the frequency selected as the frequency of the transmission wave T to be transmitted from each of the transmission antennas 25. The signal whose frequency has been increased by the synthesizer 22 is supplied to the phase control unit 23 and the mixer 33. When the multiple phase control units 23 are present, the signal whose frequency has been increased by the synthesizer 22 may be supplied to each of the multiple phase control units 23. When the multiple reception units 30 are present, the signal whose frequency has been increased by the synthesizer 22 may be supplied to the mixer 33 of each of the multiple reception units 30.
Each of the phase control units 23 controls a phase of the transmission signal supplied from the synthesizer 22. Specifically, for example, in accordance with control performed by the controller 10, each of the phase control units 23 may appropriately advance or delay the phase of the signal supplied from the synthesizer 22 to adjust the phase of the transmission signal. In this case, based on a difference between paths of the transmission waves T to be transmitted from the multiple transmission antennas 25, the phase control units 23 may adjust the phases of the respective transmission signals. The phase control units 23 appropriately adjust the phases of the respective transmission signals, so that the transmission waves T transmitted from the respective transmission antennas 25 enhance with each other in a predetermined direction to form a beam (beamforming). In this case, for example, the storage unit 40 may store a correlation between a direction of beamforming and amounts of phase by which the respective transmission signals transmitted by the respective transmission antennas 25 are to be controlled. The transmission signal whose phase is controlled by each of the phase control units 23 is supplied to a respective one of the amplifiers 24.
The amplifier 24 amplifies power (electric power) of the transmission signal supplied from the phase control unit 23 in accordance with control performed by the controller 10, for example. When the sensor 5 includes the multiple transmission antennas 25, each of the multiple amplifiers 24 may amplify power (electric power) of the transmission signal supplied from a respective one of the multiple phase control units 23 in accordance with control performed by the controller 10, for example. Since the technology for amplifying power of a transmission signal is already known, more detailed description is omitted. The amplifier 24 is connected to the transmission antenna 25.
The transmission antenna 25 outputs (transmits), as the transmission wave T, the transmission signal amplified by the amplifier 24. When the sensor 5 includes the multiple transmission antennas 25, each of the multiple transmission antennas 25 may output (transmit), as the transmission wave T, the transmission signal amplified by a respective one of the multiple amplifiers 24. Since the transmission antennas 25 can have a configuration that is the same as and/or similar to the configuration of transmission antennas for use in the known radar technology, more detailed description is omitted.
Accordingly, the sensor 5 according to the one embodiment, which includes the transmission antennas 25, can transmit transmission signals (for example, transmission chirp signals) as the transmission waves T from the respective transmission antennas 25. At least one of the functional units of the electronic device 1 may be housed in one housing. In this case, the one housing may have a hard-to-open structure. For example, the transmission antennas 25, the reception antennas 31, and the amplifiers 24 are desirably housed in one housing, and this housing desirably has a hard-to-open structure. When the sensor 5 is installed on the mobility device 100 such as an automobile, each of the transmission antennas 25 may transmit the transmission wave T to outside the mobility device 100 through a cover member such as a radar cover, for example. In this case, the radar cover may be made of a material, for example, a synthetic resin or rubber, that allows an electromagnetic wave to pass therethrough. This radar cover may also serve as a housing of the sensor 5, for example. Covering the transmission antennas 25 with a member such as the radar cover can reduce a risk of the transmission antennas 25 being damaged or malfunctioning because of a contact with an external object. The radar cover and the housing may also be referred to as a radome.
The reception antenna 31 receives the reflected wave R. The reflected wave R may be the transmission wave T reflected off the predetermined object 200. The reception antenna 31 may include multiple antennas such as the reception antennas 31A to 31D, for example. Since the reception antennas 31 can have a configuration that is the same as and/or similar to the configuration of reception antennas for use in the known radar technology, more detailed description is omitted. The reception antenna 31 is connected to the LNA 32. A reception signal based on the reflected wave R received by the reception antenna 31 is supplied to the LNA 32.
The sensor 5 according to the one embodiment can receive, from each of the multiple reception antennas 31, the reflected wave R that is the transmission wave T that has been transmitted as the transmission signal (transmission chirp signal) such as a chirp signal, for example, and has been reflected off the predetermined object 200. When the transmission chirp signal is transmitted as the transmission wave T in this manner, the reception signal based on the received reflected wave R is referred to as a reception chirp signal. That is, the sensor 5 receives the reception signal (for example, the reception chirp signal) as the reflected wave R from each of the reception antennas 31. When the sensor 5 is installed on the mobility device 100 such as an automobile, each of the reception antennas 31 may receive the reflected wave R from outside the mobility device 100 through a cover member such as a radar cover, for example. In this case, the radar cover may be made of a material, for example, a synthetic resin or rubber, that allows an electromagnetic wave to pass therethrough. This radar cover may also serve as a housing of the sensor 5, for example. Covering the reception antennas 31 with a member such as the radar cover can reduce a risk of the reception antennas 31 being damaged or malfunctioning because of a contact with an external object. The radar cover and the housing may also be referred to as a radome.
When the reception antenna 31 is installed near the transmission antenna 25, these reception antenna 31 and transmission antenna 25 may be collectively included in one sensor 5. That is, for example, one sensor 5 may include at least one transmission antenna 25 and at least one reception antenna 31. For example, one sensor 5 may include the multiple transmission antennas 25 and the multiple reception antennas 31. In such a case, one radar sensor may be covered with a cover member such as one radar cover, for example.
The LNA 32 amplifies, with low noise, the reception signal based on the reflected wave R received by the reception antenna 31. The LNA 32 may be a low-noise amplifier and amplifies, with low noise, the reception signal supplied from the reception antenna 31. The reception signal amplified by the LNA 32 is supplied to the mixer 33.
The mixer 33 mixes (multiplies) the reception signal having a radio frequency (RF) and supplied from the LNA 32 and the transmission signal supplied from the synthesizer 22 to generate a beat signal. The beat signal obtained by the mixer 33 through mixing is supplied to the IF unit 34.
The IF unit 34 performs frequency conversion on the beat signal supplied from the mixer 33 to decrease the frequency of the beat signal to an intermediate frequency (IF). The beat signal whose frequency has been decreased by the IF unit 34 is supplied to the AD conversion unit 35.
The AD conversion unit 35 digitizes the analog beat signal supplied from the IF unit 34. The AD conversion unit 35 may be configured as any analog-to-digital conversion circuit (Analog-to-Digital Converter (ADC)). The digitized beat signal obtained by the AD conversion unit 35 is supplied to the distance FFT processing unit 11 of the controller 10. When the multiple reception units 30 are present, the digitized beat signals obtained by the respective AD conversion units 35 may be supplied to the distance FFT processing unit 11.
The distance FFT processing unit 11 estimates a distance between the mobility device 100 equipped with the sensor 5 and the object 200, based on the beat signals supplied from the respective AD conversion units 35. The distance FFT processing unit 11 may include a processing unit that performs fast Fourier transform, for example. In this case, the distance FFT processing unit 11 may be configured as any circuit, any chip, or the like that performs fast Fourier transform (FFT).
The distance FFT processing unit 11 performs FFT processing (hereinafter, appropriately referred to as “distance FFT processing”) on the digitized beat signals obtained by the AD conversion units 35. For example, the distance FFT processing unit 11 may perform FFT processing on complex signals supplied from the AD conversion units 35. The digitized beat signals obtained by the AD conversion units 35 can be represented as temporal changes in signal intensity (power). The distance FFT processing unit 11 performs FFT processing on such a beat signal, so that the beat signal can be represented as a signal intensity (power) for each frequency. If a peak in a result obtained by the distance FFT processing is equal to or greater than a predetermined threshold, the distance FFT processing unit 11 may determine that the predetermined object 200 is located at the distance corresponding to the peak. For example, in a known method such as constant false alarm rate (CFAR)-based detection processing, an object (reflecting object) that reflects a transmission wave is determined to be present if a peak value that is equal to or greater than a threshold is detected from the average power or amplitude of a disturbance signal.
As described above, the sensor 5 according to the one embodiment can detect, as the target, the object 200 that reflects the transmission wave T, based on the transmission signal transmitted as the transmission wave T and the reception signal received as the reflected wave R.
The distance FFT processing unit 11 can estimate a distance to the predetermined object, based on one chirp signal. That is, the electronic device 1 can measure (estimate) the distance L illustrated in
The velocity FFT processing unit 12 estimates a relative velocity between the mobility device 100 equipped with the sensor 5 and the object 200, based on the beat signals on which the distance FFT processing has been performed by the distance FFT processing unit 11. The velocity FFT processing unit 12 may include a processing unit that performs fast Fourier transform, for example. In this case, the velocity FFT processing unit 12 may be configured as any circuit, any chip, or the like that performs fast Fourier transform (FFT).
The velocity FFT processing unit 12 further performs FFT processing (hereinafter, appropriately referred to as “velocity FFT processing”) on the beat signals on which the distance FFT processing unit 11 has performed the distance FFT processing. For example, the velocity FFT processing unit 12 may perform FFT processing on the complex signals supplied from the distance FFT processing unit 11. The velocity FFT processing unit 12 can estimate a relative velocity of the predetermined object, based on a subframe including chirp signals. Through the distance FFT processing performed on the beat signals in the above-described manner, multiple vectors can be generated. The velocity FFT processing unit 12 can estimate a relative velocity of the predetermined object by determining a phase of a peak in a result of the velocity FFT processing performed on these multiple vectors. That is, the sensor 5 can measure (estimate) a relative velocity between the mobility device 100 and the predetermined object 200 illustrated in
The distance-velocity detection determining unit 13 performs determination processing for a distance and/or a relative velocity, based on the result of the distance FFT processing performed by the distance FFT processing unit 11 and/or the result of the velocity FFT processing performed by the velocity FFT processing unit 12. The distance-velocity detection determining unit 13 determines whether the target is detected at a predetermined distance and/or a predetermined relative velocity.
The angle-of-arrival estimating unit 14 estimates a direction from which the reflected wave R arrives from the predetermined object 200, based on the result of the velocity FFT processing performed by the velocity FFT processing unit 12. The sensor 5 can estimate the direction from which the reflected wave R arrives, by receiving the reflected wave R from the multiple reception antennas 31. For example, the multiple reception antennas 31 are arranged at a predetermined interval. In this case, the transmission wave T transmitted from each of the transmission antennas 25 is reflected off the predetermined object 200 to become the reflected wave R. Each of the multiple reception antennas 31 arranged at the predetermined interval receives the reflected wave R. The angle-of-arrival estimating unit 14 can estimate the direction from which the reflected wave R arrives at each of the multiple reception antennas 31, based on the phase of the reflected wave R received by the reception antenna 31 and a difference in path of the reflected wave R. That is, the electronic device 1 can measure (estimate) the angle of arrival θ illustrated in
Various techniques for estimating a direction from which the reflected wave R arrives, based on a result of velocity FFT processing have been proposed. For example, MUSIC (MUltiple SIgnal Classification), ESPRIT (Estimation of Signal Parameters via Rotational Invariance Technique), and the like are known direction-of-arrival estimation algorithms. Thus, more detailed description of the known techniques is appropriately simplified or omitted. Information (angle information) on the angle of arrival θ estimated by the angle-of-arrival estimating unit 14 may be supplied to the object detecting unit 15.
The object detecting unit 15 detects an object located in a range to which the transmission wave T is transmitted, based on the information supplied from at least any of the distance FFT processing unit 11, the velocity FFT processing unit 12, or the angle-of-arrival estimating unit 14. The object detecting unit 15 may perform detection of an object by performing, for example, clustering processing based on the supplied distance information, velocity information, and angle information. For example, DBSCAN (Density-based spatial clustering of applications with noise) or the like is a known algorithm used in clustering of data. In the clustering processing, for example, average power of points constituting the detected object may be calculated. The distance information, the velocity information, the angle information, and the power information of the object detected by the object detecting unit 15 may be supplied to an ECU (Electronic Control Unit) or the like, for example. In this case, when the mobility device 100 is an automobile, communication may be performed using a communication interface such as a CAN (Controller Area Network), for example.
The sensor 5 illustrated in
As described above, each of the first sensor 5a and the second sensor 5b according to the one embodiment may include the transmission antenna 25, the reception antenna 31, and the controller 10. The transmission antenna 25 transmits the transmission wave T. The reception antenna 31 receives the reflected wave R that is the transmission wave T having been reflected. The controller 10 detects an object that reflects the transmission wave T, based on a transmission signal transmitted as the transmission wave T and a reception signal received as the reflected wave R.
While the present disclosure has been described based on the various drawings and the embodiments, it is to be noted that a person skilled in the art can easily make various variations or corrections based on the present disclosure. Therefore, it is to be noted that these variations or corrections are within the scope of the present disclosure. For example, functions and the like included in each functional unit can be rearranged without causing any logical contradiction. Multiple functional units or the like may be combined into one or may be divided. The embodiments according to the present disclosure described above are not limited to strict implementation according to the respective embodiments described above, and may be implemented by appropriately combining the features or omitting part thereof. That is, a person skilled in the art can make various variations and corrections to the contents of the present disclosure based on the present disclosure. Therefore, these variations and corrections are within the scope of the present disclosure. For example, in each embodiment, each functional unit, each means, each step, or the like can be added to another embodiment or replaced with each functional unit, each means, each step, or the like in another embodiment without causing any logical contradiction. In each embodiment, multiple functional units, means, steps, or the like may be combined into one or may be divided. The embodiments of the present disclosure described above are not limited to strict implementation according to the respective embodiments described above, and may be implemented by appropriately combining the features or omitting part thereof.
For example, the electronic device 1 according to the above-described embodiment includes the two sensors 5 (the first sensor 5a and the second sensor 5b). However, the electronic device 1 according to the one embodiment may include the three or more sensors 5. As illustrated in
The embodiments described above are not limited to implementation as the electronic device 1. For example, the embodiments described above may be implemented as a method for controlling a device such as the electronic device 1. For example, the embodiments described above may be implemented as a program executed by a device such as the electronic device 1.
Number | Date | Country | Kind |
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2020-197127 | Nov 2020 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/041633 | 11/11/2021 | WO |