Patent ID: 12248063

DESCRIPTION OF EMBODIMENTS

The convenience can be improved if whether installed states of a plurality of sensors are appropriate can be determined in an electronic device including the sensors that receive a reflected wave that is a transmission wave transmitted and reflected off a predetermined object. An object of the present disclosure is to provide an electronic device capable of determining whether installed states of a plurality of sensors are appropriate in the electronic device that performs detection of an object by using the sensors, a method for controlling the electronic device, and a program for controlling the electronic device. According to one embodiment, an electronic device capable of determining whether installed states of a plurality of sensors are appropriate in the electronic device that performs detection of an object by using the sensors, a method for controlling the electronic device, and a program for controlling the electronic device can be provided. 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 thus is capable of detecting 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 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 the mobility device. At least one of the transmission antenna and the reception antenna may be included in a radar sensor or the like installed on the mobility device, for example.

A configuration in which the electronic device according to the one embodiment is mounted in an automobile such as a passenger car is described below as a typical example. 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 a bus, a truck, a taxi, a motorcycle, a bicycle, a ship, an aircraft, an ambulance, a fire engine, a helicopter, 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 the sensor and a predetermined object when at least one of the sensor and the object is movable. The electronic device according to the one embodiment is also capable of measuring e distance or the like between the sensor and the object even when both the sensor and the object are stationary. In addition, 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 less than or equal to 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 electronic device according to the one embodiment detects an object is described first.

FIG.1is a diagram for describing how the electronic device according to the one embodiment is used.FIG.1illustrates an example in which a sensor including a transmission antenna and a reception antenna according to the one embodiment is installed on a mobility device.

A sensor5including a transmission antenna and a reception antenna according to the one embodiment is installed on a mobility device100illustrated inFIG.1. It is assumed that an electronic device1according to the one embodiment is also mounted (for example, built) in the mobility device100illustrated inFIG.1. A specific configuration of the electronic device1is described later. The sensor5may include at least one of the transmission antenna and the reception antenna, for example. The sensor5may also appropriately include at least any of other functional units, such as at least part of a control unit10(FIG.2) included in the electronic device1. The mobility device100illustrated inFIG.1may be an automotive vehicle such as a passenger car but may be a mobility device of any type. InFIG.1, the mobility device100may move (travel or slowly travel), for example, in a positive Y-axis direction (traveling direction) illustrated inFIG.1or in another direction, or may be stationary without moving.

As illustrated inFIG.1, the sensor5including the transmission antenna is installed on the mobility device100. In the example illustrated inFIG.1, only one sensor5including the transmission antenna and the reception antenna is installed at a front portion of the mobility device100. The position where the sensor5is installed on the mobility device100is not limited to the position illustrated inFIG.1and may be another appropriate position. For example, the sensor5illustrated inFIG.1may be installed on a left side, on a right side, and/or at a rear portion of the mobility device100. The number of such sensors5may be any number equal to or greater than 1 depending on various conditions (or requirements) such as a range and/or an accuracy of measurement performed at the mobility device100.

The sensor5transmits an electromagnetic wave as a transmission wave from the transmission antenna. For example, when a predetermined object (for example, an object200illustrated inFIG.1) is located around the mobility device100, at least part of the transmission wave transmitted from the sensor5is reflected off the object to become a reflected wave. For example, the reception antenna of the sensor5receives such a reflected wave. In this manner, the electronic device1mounted in the mobility device100can detect the object.

The sensor5including the transmission antenna may be typically a radar (Radio Detecting and Ranging) sensor that transmits and receives a radio wave. However, the sensor5is not limited to a radar sensor. The sensor5according 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. Each of these sensors can include, for example, a patch antenna. Since the technologies such as RADAR and LIDAR are already known, detailed description may be appropriately simplified or omitted.

The electronic device1mounted in the mobility device100illustrated inFIG.1receives, from the reception antenna, the reflected wave of the transmission wave transmitted from the transmission antenna of the sensor in this manner, the electronic device1can detect the predetermined object200located within a predetermined distance from the mobility device100. For example, as illustrated inFIG.1, the electronic device1can measure a distance L between the mobility device100, which is vehicle of interest, and the predetermined object200. The electronic device1can also measure a relative velocity between the mobility device100, which is the vehicle of interest, and the predetermined object200. The electronic device1can further measure a direction (an angle of arrival9) from which the reflected wave from the predetermined object200arrives at the mobility device100, which is the vehicle of interest.

The object200may be, for example, at least any of an oncoming automobile traveling in a lane adjacent to a lane of the mobility device100, an automobile traveling side by side with the mobility device100, an automobile traveling in front of or behind the mobility device100in the same lane, and the like. The object200may also be any object located around the mobility device100, such as a motorcycle, a bicycle, a stroller, a pedestrian, a guardrail, a median strip, a road sign, a step on a sidewalk, a wall, a manhole, or an obstacle. The object200may be in motion or stationary. For example, the object200may be an automobile or the like that is parked or stationary around the mobility device100. In addition the object200may be located not only on a road but also at an appropriate place such as on a sidewalk, in a farm, on a farmland, in a parking lot, in a vacant lot, a space on a road, in a store, at a crossing, on the water, in the air, in a gutter, in a river, in another mobility device, in a building, inside or outside of other structures. In the present disclosure, the object200detected by the sensor includes living things such as a person, a dog, a cat, a horse, and other animals in addition to non-living things. The object200detected by the sensor5in the present disclosure includes a target, which includes a person, an object, and an animal, to be detected with the radar technology.

InFIG.1, a ratio between a size of the sensor5and a size of the mobility device100does not necessarily indicate an actual ratio.FIG.1illustrates the sensor5that is installed on an outer portion of the mobility device100. However, in one embodiment, the sensor5may be installed at various positions of the mobility device100. For example, in one embodiment, the sensor5may be installed inside a bumper of the mobility device100so as not to be seen in the appearance of the mobility device100. In addition, the position where the sensor5is installed in the mobility device100may be either outside or inside of the mobility device100. The inside of the mobility device100may refer to, for example, inside of the body of the mobility device100, inside of the bumper, inside of a headlight, a space in the mobility device100, or any combination of these.

Description is given below on the assumption that the transmission antenna of the sensor5transmits 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) as a typical example. For example, the transmission antenna of the sensor5may transmit a radio wave having a frequency bandwidth of 4 GHz such as from 77 GHz to 81 GHz.

FIG.2is a functional block diagram schematically illustrating an example of a configuration of the electronic device1according to the one embodiment. An example of the configuration of the electronic device1according to the one embodiment is described below.

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 bandwidth of 79 GHz has a characteristic that the usable frequency bandwidth is wider than another millimeter-wave and/or quasi-millimeter-wave radar of a frequency band of 24 GHz, 60 GHz, or 76 GHz, for example. Such an embodiment is described below. The FMCW radar scheme used in the present disclosure may include an FCM scheme (Fast-Chirp Modulation) for transmitting chirp signals at a shorter period than usual. A signal generated by a signal generating unit21is not limited to a signal of the FM-CW scheme. The signal generated by the signal generating unit21may be a signal of various schemes other than the FM-CW scheme. A transmission signal sequence stored in a storage unit40may change in accordance with these various schemes. For example, in the case of a radar signal of the FM-CW scheme described above, a signal whose frequency increases for each time sample and a signal whose frequency decreases for each time sample may be used. More detailed description of the various schemes described above is omitted because known techniques can be appropriately employed.

As illustrated inFIG.2, the electronic device1according to the one embodiment includes the sensor5and an ECU (Electronic Control Unit)50. The ECU50controls various operations of the mobility device100. The ECU50may be constituted by at least one or more ECUs. The electronic device1according to the one embodiment includes the control unit10. The electronic device1according to the one embodiment may also appropriately include another functional unit such as at least any of a transmission unit20, reception units30A to30D, and the storage unit40. As illustrated inFIG.2, the electronic device1may include a plurality of reception units such as the reception units30A to30D. When the reception units30A,30B,30C, and30D are not distinguished from one another, the reception units30A,30B,30C, and30D are simply referred to as “reception units30” below.

The control unit10may include a distance FFT processing unit11, a velocity FF1processing unit12, an angle-of-arrival estimating unit13, an object detecting unit14, a detection range determining unit15, and a parameter setting unit16. These functional units included in the control unit10are further described later.

As illustrated inFIG.2, the transmission unit20may include the signal generating unit21, a synthesizer22, phase control units23A and23B, amplifiers24A and24B, and transmission antennas25A and25B. When the phase control units23A and23B are not distinguished from each other, the phase control units23A and23B are simply referred to as phase control units23″ below. When the amplifiers24A and24B are not distinguished from each other, the amplifiers24A and24B are simply referred to as “amplifiers24” below. When the transmission antennas25A and25B are not distinguished from each other, the transmission antennas25A and25B are simply referred to as “transmission antennas25” below.

As illustrated inFIG.2, each of the reception units30may include a respective one of reception antennas31A to31D. When the reception antennas31A,31B,31C, and31D are not distinguished from one another, the reception antennas31A,31B,31C, and31D are simply referred to as “reception antennas31” below. As illustrated inFIG.2, each of the plurality of reception units30may include an LNA32, a mixer33, an IF unit34, and an AD conversion unit35. The reception units30A to30D may have the same and/or similar configuration.FIG.2schematically illustrates the configuration of only the reception unit30A as a representative example.

The sensor5described above may include, for example, the transmission antennas25and the reception antennas31. The sensor5may also appropriately include at least any of other functional units such as the control unit10.

The control unit10included in the electronic device1according to the one embodiment is capable of controlling the individual functional units of the electronic device1and also controlling operations of the entire electronic device1. To provide control and processing capabilities for executing various functions, the control unit10may include at least one processor, for example, a CPU (Central Processing Unit). The control unit10may 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 a plurality of integrated circuits and discrete circuits connected to be able to perform communication. The processor may be implemented on the basis of various other known technologies. In the one embodiment, the control unit10may be configured as, for example, a CPU and a program executed by the CPU. The control unit10may appropriately include a memory required for operations of the control unit10.

The storage unit40may store a program executed by the control unit10, results of processing performed by the control unit10, etc. The storage unit40may function as a work memory of the control unit10. The storage unit40may be constituted by, for example, a semiconductor memory or a magnetic disk. However, the storage unit40is not limited to these, and can be any storage device. The storage unit40may be, for example, a storage medium such as a memory card inserted to the electronic device1according to the present embodiment. The storage unit40may be an internal memory of the CPU used as the control unit10as described above.

In the one embodiment, the storage unit40may store various parameters for setting a range in which an object is detected on the basis of a transmission wave T transmitted from each transmission antenna25and a reflected wave R received from each reception antenna31. Such parameters are further described later.

In the electronic device1according to the one embodiment, the control unit10is capable of controlling at least one of the transmission unit20and the reception units30. In tris case, the control unit10may control at least one of the transmission unit20and the reception units30on the basis of various kinds of information stored in the storage unit40. In the electronic device1according to the one embodiment, the control unit10may instruct the signal generating unit21to generate a signal or may control the signal generating unit21to generate a signal.

In accordance with control performed by the control unit10, the signal generating unit21generates a signal (transmission signal) to be transmitted as the transmission wave T from each of the transmission antennas25. When generating the transmission signal, the signal generating unit21may allocate a frequency of the transmission signal in accordance with control performed by the control unit10, for example. Specifically, the signal generating unit21may allocate a frequency of the transmission signal in accordance with a parameter set by the parameter setting unit16. For example, the signal generating unit21receives frequency information from the control unit10(the parameter setting unit16) 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 unit21may include a functional unit serving as a voltage control oscillator (VCO), for example.

The signal generating unit21may be configured as hardware having the function, as for example a microcomputer, or as for example 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, as for example a microcomputer if possible, or as for example a processor such as a CPU and a program or the like executed by the processor.

In the electronic device1according to the one embodiment, the signal generating unit21may generate a transmission signal (transmission chirp signal) such as a chirp signal, for example. In particular, the signal generating unit21may generate a signal (linear chirp signal) whose frequency changes linearly and periodically. For example, the signal generating unit21may generate a chirp signal whose frequency linearly and periodically increases from 77 GHz to 81 GHz as time elapses. For example, the signal generating unit21may 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. The signal generated by the signal generating unit21may be set in advance by the control unit10, for example. The signal generated by the signal generating unit21may be stored in advance in the storage unit40or the like, for example. Since chirp signals used in a technical field such as the radar are known, more detailed description is appropriately simplified or omitted. The signal generated by the signal generating unit21is supplied to the synthesizer22.

FIG.3is a diagram for describing an example of chirp signals generated by the signal generating unit21.

InFIG.3, the horizontal axis represents elapsed time, and the vertical axis represents a frequency. In the example illustrated inFIG.3, the signal generating unit21generates linear chirp signals whose frequency changes linearly and periodically. InFIG.3, the individual chirp signals are denoted by c1, c2, . . . , c8. As illustrated inFIG.3, the frequency of each chirp signal linearly Increases as time elapses.

In the example illustrated inFIG.3, eight chirp signals c1, c2, . . . , c8constitute one subframe. That is, each of subframes such as a subframe1and a subframe2illustrated inFIG.3includes eight chirp signals c1, c2, . . . , c8. In the example illustrated inFIG.3,16subframes such as the subframes1to16constitute one frame. That is, each of frames such as a frame1and a frame2illustrated inFIG.3includes16subframes. As illustrated inFIG.3, a frame interval of a predetermined length may be included between frames.

InFIG.3, the frame2and subsequent frames may have the same and/or similar configuration. InFIG.3, the frame3and subsequent frames may have the same and/or similar configuration. In the electronic device1according to the one embodiment, the signal generating unit21may generate a transmission signal as any number of frames. InFIG.3, an illustration of some chirp signals is omitted. As described above, a relationship between time and a frequency of the transmission signal generated by the signal generating unit21may be stored in the storage unit40or the like, for example.

As described above, the electronic device according to the one embodiment may transmit a transmission signal constituted by subframes each including a plurality of chirp signals. The electronic device1according to the one embodiment may transmit a transmission signal constituted by frames each including a predetermined number of subframes.

Description is given below on the assumption that the electronic device1transmits a transmission signal having a frame structure illustrated inFIG.3. However, the frame structure illustrated inFIG.3is an example. For example, the number of chirp signals included in one subframe is not limited to eight. In the one embodiment, the signal generating unit21may generate a subframe including any number (for example, a plurality) of chirp signals. A subframe structure illustrated inFIG.3is also an example. For example, the number of subframes included in one frame is not limited to16. In the one embodiment, the signal generating unit21may generate a frame including any number (for example, a plurality) of subframes.

Referring back toFIG.2, the synthesizer22increases the frequency of the signal generated by the signal generating unit21to a frequency in a predetermined frequency band. The synthesizer22may increase the frequency of the signal generated by the signal generating unit21to a frequency selected as a frequency of the transmission wave T to be transmitted from each of the transmission antennas25. The frequency selected as the frequency of the transmission wave T to be transmitted from each of the transmission antennas25may be set by the control unit10, for example. For example, the frequency selected as the frequency of the transmission wave T to be transmitted from each of the transmission antennas25may be a frequency selected by the parameter setting unit16. The frequency selected as the frequency of the transmission wave T to be transmitted from each of the transmission antennas25may be stored in the storage unit40, for example. The signal whose frequency has been increased by the synthesizer22is supplied to a phase control unit23and the mixer33. When the plurality of phase control units23are present, the signal whose frequency has been increased by the synthesizer22may be supplied to each of the plurality of phase control units23. When the plurality of reception units30are present, the signal whose frequency has been increased by the synthesizer22may be supplied to the mixer33of each of the plurality of reception units30.

Each of the phase control units23controls a phase of the transmission signal supplied from the synthesizer22. Specifically, for example, in accordance with control performed by the control unit10, each of the phase control units23may appropriately advance or delay the phase of the signal supplied from the synthesizer22to adjust the phase of the transmission signal. In this case, on the basis of a difference between paths of the transmission waves T to be transmitted from the plurality of transmission antennas25, the phase control units23may adjust the phases of the respective transmission signals. The phase control units23appropriately adjust the phases of the respective transmission signals, so that the transmission waves T transmitted from the plurality of transmission antennas25enhance with each other in a predetermined direction to form a beam (beamforming). In this case, a correlation between a direction of beamforming and amounts of phase by which the respective transmission signals transmitted by the plurality of transmission antennas25are to be controlled may be stored in the storage unit40, for example. The transmission signal whose phase is controlled by each of the phase control units23is supplied to a respective one of the amplifiers24.

The amplifier24amplifies power (electric power) of the transmission signal supplied from the phase control unit23in accordance with control performed by the control unit10, for example. When the sensor5includes the plurality of transmission antennas25, each of the plurality of amplifiers24may amplify power (electric power) of the transmission signal supplied from a respective one of the plurality of phase control units23in accordance with control performed by the control unit10, for example. Since the technology for amplifying power of a transmission signal is already known, more detailed description is omitted. Each of the amplifiers24is connected to a respective one of the transmission antennas25.

The transmission antenna25outputs (transmits), as the transmission wave. The transmission signal amplified by the amplifier24. When the sensor5includes the plurality of transmission antennas25, each of the plurality of transmission antennas25may output (transmit), as the transmission wave T, the transmission signal amplified by a respective one of the plurality of amplifiers24. Since the transmission antennas25can be configured in a manner that is the same as and/or similar to that of transmission antennas for use in the known radar technology, more detailed description is omitted.

The electronic device1according to the one embodiment includes the transmission antennas25and is capable of transmitting transmission signals (for example, transmission chirp signals) as the transmission waves T from the respective transmission antennas25in this manner. At least one of the functional units constituting the electronic device1may be housed in one housing. In this case, the one housing may have a hard-to-open structure. For example, the transmission antennas25, the reception antennas31, and the amplifiers24are desirably housed in one housing, and this housing desirably has a hard-to-open structure. When the sensor is installed on the mobility device100such as an automobile, each of the transmission antennas25may transmit the transmission wave T to outside the mobility device100through 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 electromagnetic waves to pass therethrough. This radar cover may also serve as a housing of the sensor5, for example. The transmission antennas25are covered with a member such as the radar cover, so that a risk of the transmission antennas25being damaged or malfunctioning because of a contact with an external object can be reduced. The radar cover and the housing may also be referred to as a radome.

FIG.2illustrates an example in which the electronic device1includes two transmission antennas25. However, in the one embodiment, the electronic device1may include any number of transmission antennas25. On the other hand, in the one embodiment, the electronic device1may include the plurality of transmission antennas25in the case where the transmission waves T transmitted from the respective transmission antennas25form a beam in a predetermined direction. In the one embodiment, the electronic device1may include a plurality of transmission antennas25. In this case, the electronic device1may include the plurality of phase control units23and the plurality of amplifiers24to correspond to the plurality of transmission antennas25. Each of the plurality of phase control units23may control the phase of a respective one of the plurality of transmission waves supplied from the synthesizer22and to be transmitted from the plurality of transmission antennas25. Each of the plurality of amplifiers24may amplify power of a respective one of the plurality of transmission signals to be transmitted from the plurality of transmission antennas25. In this case, the sensor5may include the plurality of transmission antennas. As described above, when the electronic device1illustratedFIG.2includes the plurality of transmission antennas25, the electronic device1may include a plurality of functional units necessary for transmitting the transmission waves T from the plurality of transmission antennas25.

The reception antenna31receives the reflected wave R. The reflected wave R may be the transmission wave T reflected off the predetermined object200. As the reception antenna31, a plurality of antennas such as the reception antennas31A to31D, for example, may be included. Since the reception antennas31can be configured in a manner that is the same as and/or similar to that of reception antennas for use in the known radar technology, more detailed description is omitted. The reception antenna31is connected to the LNA32. A reception signal based on the reflected wave R received by the reception antenna31is supplied to the LNA

The electronic device1according to the one embodiment can receive, from each of the plurality of reception antennas31, 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 object200. 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 electronic device1receives the reception signal (for example, the reception chirp signal) as the reflected wave R from each of the reception antennas31. When the sensor5is installed on the mobility device100such as an automobile, each of the reception antennas31may receive the reflected wave R from outside the mobility device100through 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 electromagnetic waves to pass therethrough. This radar cover may also serve as a housing of the sensor5, for example. The reception antennas31are covered with a member such as the radar cover, so that a risk of the reception antennas31being damaged or malfunctioning because of a contact with an external object can be reduced. The radar cover and the housing may also be referred to as a radome.

When the reception antennas31are installed near the transmission antennas25, these may be collectively included in one sensor5. That is, for example, one sensor5may Include at least one transmission antenna25and at least one reception antenna31. For example, one sensor5may include the plurality of transmission antennas25and the plurality of reception antennas31. In such a case, one radar sensor may be covered with a cover member such as one radar cover, for example.

The LNA32amplifies, with low noise, the reception signal based on the reflected wave R received by the reception antenna31. The LNA32may be a low-noise amplifier and amplifies, with low noise, the reception signal supplied from the reception antenna31. The reception signal amplified by the LNA32is supplied to the mixer33.

The mixer33mixes (multiplies) the reception signal having a radio frequency (RF) supplied from the LNA32and the transmission signal supplied from the synthesizer22to generate a beat signal. The beat signal obtained by the mixer33through mixing is supplied to the IF unit34.

The IF unit34performs frequency conversion on the beat signal supplied from the mixer33to decrease the frequency of the beat signal to an intermediate frequency (IF). The beat signal whose frequency has been decreased by the IF unit34is supplied to the AD conversion unit35.

The AD conversion unit35digitizes the analog beat signal supplied from the IF unit34. The AD conversion unit35may be constituted by any analog-to-digital conversion circuit (Analog to Digital Converter (ADC)). The digitized beat signal obtained by the AD conversion unit35is supplied to the distance FFT processing unit11of the control unit10. In the case where there are the plurality of reception units30, the digitized beat signals obtained by the plurality of AD conversion units35may be supplied to the distance FFT processing unit11.

The distance FFT processing unit11estimates a distance between the mobility device100equipped with the electronic device1and the object200on the basis of the beat signals supplied from the respective AD conversion units35. The distance FFT processing unit11may include a processing unit that performs fast Fourier transform, for example. In this case, the distance FFT processing unit11may be constituted by any circuit, any chip, or the like that performs fast Fourier transform (FFT). The distance FFT processing unit11may preform Fourier transform other than fast Fourier transform.

The distance FFT processing unit11performs FFT processing (hereinafter, appropriately referred to as “distance FFT processing”) on the digitized beat signals obtained by the AD conversion units35. For example, the distance FFT processing unit11may perform the FFT processing on a complex signal supplied from each of the AD conversion units35. The digitized beat signal obtained by each of the AD conversion units35can be represented as a temporal change in signal intensity (power). The distance FFT processing unit11performs 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 unit11may determine that the predetermined object200is located at the distance corresponding to the peak. For example, a method for determining that there is an object (reflecting object) that reflects a transmission wave when a peak value that is equal to or greater than a threshold is detected from the average power or amplitude of a disturbance signal, such as a constant false alarm rate (CFAR) detection process, is known.

As described above, the electronic device1according to the one embodiment can detect the object200that reflects the transmission wave T on the basis of the transmission signal transmitted as the transmission wave T and the reception signal received as the reflected wave R. In the one embodiment, the operation described above may be performed by the control unit10of the electronic device1.

The distance FFT processing unit11can estimate a distance to the predetermined object on the basis of one chirp signal (for example, c1illustrated inFIG.3). That is, the electronic device1can measure (estimate) the distance L illustrated inFIG.1by performing the distance FFT processing. Since a technique for measuring (estimating) a distance to a predetermined object by performing FFT processing on a beat signal is known, more detailed description is appropriately simplified or omitted. The results (for example, distance information) of the distance FFT processing performed by the distance FFT processing unit11may be supplied to the velocity FFT processing unit12. The results of the distance FFT processing performed by the distance FFT processing unit11may also be supplied to the object detecting unit14, etc.

The velocity FFT processing unit12estimates a relative velocity between the mobility device100equipped with the electronic device1and the object200on the basis of the beat signals on which the distance FFT processing has been performed by the distance FFT processing unit11. The velocity FFT processing unit12may include a processing unit that performs fast Fourier transform, for example. In this case, the velocity FFT processing unit12may be constituted by any circuit, any chip, or the like that performs fast Fourier transform (FFT). The velocity FFT processing unit12may preform Fourier transform other than fast Fourier transform.

The velocity FFT processing unit12further performs FFT processing (hereinafter, appropriately referred to as “velocity FFT processing”) on each beat signal on which the distance FFT processing has been performed by the distance FFT processing unit11. For example, the velocity FFT processing unit12may perform the FFT processing on a complex signal supplied from the distance FFT processing unit11. The velocity FFT processing unit12can estimate a relative velocity to the predetermined object on the basis of a subframe (for example, the subframe1illustrated inFIG.3) including chirp signals. When the distance FFT processing is performed on the beat signal in the above-described manner, a plurality of vectors can be generated. The velocity FFT processing unit12can estimate a relative velocity to the predetermined object by determining a phase of a peak in a result of the velocity FFT processing performed on the plurality of vectors. That is, the electronic device1can measure (estimate) a relative velocity between the mobility device100and the predetermined object200illustrated inFIG.1by performing the velocity FFT processing. Since a technique for measuring (estimating) a relative velocity to a predetermined object by performing velocity FFT processing on a result of distance FFT processing is known, more detailed description is appropriately simplified or omitted. Results (for example, velocity information) of the velocity FFT processing performed by the velocity FFT processing unit12may be supplied to the angle-of-arrival estimating unit13. The results of the velocity FFT processing performed by the velocity FFT processing unit12may also be supplied to the object detecting unit14, etc.

The angle-of-arrival estimating unit13estimates a direction from which the reflected wave R arrives from the predetermined object200on the basis of the results of the velocity FFT processing performed by the velocity FFT processing unit12. The electronic device1can estimate the direction from which the reflected wave R arrives by receiving the reflected wave R from the plurality of reception antennas31. For example, the plurality of reception antennas31are arranged at a predetermined interval. In this case, the transmission wave T transmitted from each of the transmission antennas25is reflected off the predetermined object200to become the reflected wave R. Each of the plurality of reception antennas31arranged at the predetermined interval receives the reflected wave R. The angle-of-arrival estimating unit13can estimate the direction from which the reflected wave R arrives at each of the plurality of reception antennas31on the basis of the phase of the reflected wave R received by the reception antenna31and a difference in path of the reflected wave R. That is, the electronic device1can measure (estimate) the angle of arrival θ illustrated inFIG.1on the basis of the results of the velocity FFT processing.

Various techniques for estimating a direction from which the reflected wave R arrives on the basis of 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 as known arriving direction estimation algorithms. Thus, more detailed description of the known techniques is appropriately simplified or omitted. Information (angle information) of the angle of arrival θ estimated by the angle-of-arrival estimating unit13may be supplied to the object detecting unit14.

The object detecting unit14detects an object located in a range in which the transmission waves T are transmitted, on the basis of the information supplied from at least any of the distance FFT processing unit11, the velocity FFT processing unit12, and the angle-of-arrival estimating unit13. The object detecting unit14may perform detection of an object by performing, for example, clustering processing on the basis of the supplied distance information, velocity information, and angle information. For example, DBSCAN (Density-based spatial clustering of applications with noise) or the like is known as an 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 power information of the object detected by the object detecting unit14may be supplied to the detection range determining unit15. The distance information, the velocity information, the angle information, and the power information of the object detected by the object detecting unit14may be supplied to the ECU50. In this case, when the mobility device100is an automobile, communication may be performed using a communication interface such as a CAN (Controller Area Network), for example.

The detection range determining unit15determines a range (hereinafter, also referred to as an “object detection range”) in which an object that reflects the transmission wave T is to be detected on the basis of the transmission signal and the reception signal. The detection range determining unit15may determine the object detection range on the basis of an operation performed by a driver or the like of the mobility device100equipped with the electronic device1, for example. For example, the detection range determining unit15may determine the object detection range suitable for parking assist when a parking assist button is operated by a driver or the like of the mobility device100. The detection range determining unit15may determine the object detection range on the basis of an instruction from the ECU50, for example. For example, when the ECU50determines that the mobility device100is to travel backward, the detection range determining unit15may determine, on the basis of an instruction from the ECU50, the object detection range suitable when the mobility device100travels backward. The detection range determining unit15may determine the object detection range on the basis of a change in an operation state for steering, an accelerator, gears, or the like of the mobility device100, for example. The detection range determining unit15may determine the object detection range on the basis of a result of detection of an object performed by the object detecting unit14.

The parameter setting unit16sets various parameters that define a transmission signal and a reception signal with which an object that reflects the transmission wave T as the reflected wave R is to be detected. That is, the parameter setting unit16sets various parameters for transmitting the transmission wave T from each transmission antenna25and various parameters for receiving the fleeted wave R from each reception antenna31.

In particular, in the one embodiment, the parameter setting unit16may set various parameters related to transmission of the transmission wave T and reception of the reflected wave R in order to detect an object in the object detection range described above. For example, the parameter setting unit16may define a range or the like in which the reflected wave R is desirably received in order to detect the object located in the object detection range by receiving the reflected wave R. For example, the parameter setting unit16may define a range or the like to which a beam of the transmission waves T is desirably directed in order to detect an object located in the object detection range by transmitting the transmission waves T from the plurality of transmission antennas25. The parameter setting unit16may also set various parameters for transmitting the transmission wave T and receiving the reflected wave R.

The various parameters set by the parameter setting unit16may be supplied to the signal generating unit21. Thus, the signal generating unit21can generate the transmission signal to be transmitted as the transmission waves T on the basis of the various parameters set by the parameter setting unit16. The various parameters set by the parameter setting unit16may be supplied to the object detecting unit14. Thus, the object detecting unit14can perform object detection processing in the object detection range determined on the basis of the various parameters set by the parameter setting unit16.

The ECU50included in the electronic device1according to the one embodiment is capable of controlling the functional units of the mobility device100and also controlling operations of the entire mobility device100. In the electronic device1according to the one embodiment, the ECU50may control the plurality of sensors5as described below. To provide control and processing capabilities for executing various functions, the ECU50may include at least one processor, for example, a CPU (Central Processing Unit). The ECU50may 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 a plurality of integrated circuits and discrete circuits connected to be able to perform communication. The processor may be implemented on the basis of various other known technologies. In the one embodiment, the ECU50may be configured as, for example, a CPU and a program executed by the CPU. The ECU50may appropriately include a memory required for operations of the ECU50. At least part of the functions of the control unit10may be functions of the ECU50, or at least part of the functions of the ECU50may be functions of the control unit10.

The electronic device1illustrated inFIG.2includes the two transmission antennas25and the four reception antennas31. However, the electronic device1according to the one embodiment may include any number of transmission antennas25and any number of reception antennas31. For example, by including the two transmission antennas25and the four reception antennas31, the electronic device1can be regarded to include a virtual antenna array that is virtually constituted by eight antennas. As described above, the electronic device1may receive the reflected wave R of16subframes illustrated inFIG.3by using, for example, the eight virtual antennas.

FIG.4is a diagram illustrating an example of the arrangement of the transmission antennas and the reception antennas in the sensor of the electronic device according to the one embodiment.

As illustrated inFIG.4, the sensor5of the electronic device1according to the one embodiment may include, for example, two transmission antennas25A and25A′. As illustrated inFIG.4, the sensor5of the electronic device1according to the one embodiment may include four reception antennas31A,31B,31C, and31D.

The four reception antennas31A,31B,31C, and31D are arranged in the horizontal direction (in an X-axis direction) at an interval of λ/2, where λ denotes a wavelength of the transmission wave T. By arranging the plurality of reception antennas31in the horizontal direction and receiving the transmission wave T with the plurality of reception antennas31in this manner, the electronic device1can estimate the direction from which the reflected wave R arrives. The wavelength λ of the transmission wave T may be a wavelength of the transmission wave T having a center frequency of 79 GHz when a frequency band of the transmission wave T is, for example, from 77 GHz to 81 GHz.

The two transmission antennas25A and25A′ are arranged in a vertical direction (a Z-axis direction) at an interval of λ/2, where λ denotes the wavelength of the transmission wave T. By arranging the plurality of transmission antennas25in the vertical direction and transmitting the transmission waves T with the plurality of transmission antennas25in this manner, the electronic device1can change the direction of the beam of the transmission waves T in the vertical direction.

As illustrated inFIG.4, the sensor5of the electronic device1according to the one embodiment may include, for example, four transmission antennas25A,25A′,25B, and25B′.

As illustrated inFIG.4, the two transmission antennas25A and25B are arranged in the horizontal direction (the X-axis direction) at an interval of λ/2, where λ denotes the wavelength of the transmission wave T. As illustrated inFIG.4, the two transmission antennas25A′ and25B′ are arranged also in the horizontal direction (the X-axis direction) at an interval of λ/2, where λ denotes the wavelength of the transmission wave T. By arranging the plurality of transmission antennas25in the horizontal direction and transmitting the transmission waves T with the plurality of transmission antennas25in this manner, the electronic device1can change the direction of the beam of the transmission waves T also in the horizontal direction.

On the other hand, as illustrated inFIG.4, the two transmission antennas25B and25B′ are arranged in the vertical direction (the Z-axis direction) at an interval of λ/2, where λ denotes the wavelength of the transmission wave T. In the arrangement illustrated inFIG.4, by arranging the plurality of transmission antennas25in the vertical direction and transmitting the transmission waves T with the plurality of transmission antennas25in this manner, the electronic device1can change the direction of the beam of the transmission waves T in the vertical direction.

When the electronic device1according to the one embodiment performs beamforming of the transmission waves T transmitted from the plurality of transmission antennas25, the plurality of transmission waves T may be set in phase in a predetermined direction on the basis of a difference between paths along which the transmission waves T are transmitted. In the electronic device1according to the one embodiment, in order to set the individual transmission waves T in phase in a predetermined direction, for example, the phase control units23may control the phase of at least one of the transmission waves transmitted from the plurality of transmission antennas25.

An amount of phase to be controlled to set the plurality of transmission waves T in phase in a predetermined direction may be stored in the storage unit40in association with the predetermined direction. That is, a relationship between a direction of the beam and an amount of phase for beamforming may be stored in the storage unit40.

Such a relationship may be determined on the basis of actual measurement performed in a test environment, for example, before the electronic device1performs detection of an object. When such a relationship is not stored in the storage unit40, a relationship appropriately estimated by the phase control units23on the basis of predetermined data such as past measurement data may be used. When such a relationship is not stored in the storage unit40, the phase control units23may acquire an appropriate relationship by connecting to an external device via a network, for example.

In the electronic device1according to the one embodiment, at least one of the control unit10and the phase control units23may perform control for performing beamforming of the transmission waves T transmitted from the plurality of transmission antennas25. In the electronic device1according to the one embodiment, a functional unit including at least the phase control units23is also referred to as a transmission control unit.

As described above, in the electronic device1according to the one embodiment, the transmission antenna25may include a plurality of transmission antennas. In the electronic device1according to the one embodiment, the reception antenna31may also include a plurality of reception antennas. In the electronic device1according to the one embodiment, the transmission control unit (for example, the phase control units23) may perform control such that the transmission waves T transmitted from the plurality of transmission antennas25form a beam in a predetermined direction (beamforming). In the electronic device1according to the one embodiment, the transmission control unit (for example, the phase control units23) may form a beam in a direction toward the object detection range.

In the electronic device1according to the one embodiment, the transmission antennas25may include a plurality of transmission antennas25arranged to include a vertical direction component as described above. In this case, in the electronic device1according to the one embodiment, the phase control units23(transmission control unit) may change the direction of the beam to the direction toward the object detection range with the vertical direction component included.

In the electronic device1according to the one embodiment, the transmission antennas25may include a plurality of transmission antennas25arranged to include a horizontal direction component as described above. In this case, in the electronic device1according to the one embodiment, the phase control units23(transmission control unit) may change the direction of the beam to the direction toward the object detection range with the horizontal direction component included.

In the electronic device1according to the one embodiment, the transmission control unit (for example, the phase control units23) may form a beam in a direction that covers at least part of the object detection range. In the electronic device1according to the one embodiment, the transmission control unit (for example, the phase control units23) may control the phase of at least one of the plurality of transmission waves such that the transmission waves T each transmitted from a respective one of the plurality of transmission antennas25are in phase in a predetermined direction.

The electronic device1according to the one embodiment is capable of calculating a phase compensation value on the basis of frequency information of wide frequency band signals (for example, FMCW signals) output from the plurality of transmission antennas25and performing frequency-dependent phase compensation for each of the plurality of transmission antennas. Consequently, the electronic device1according to the one embodiment can perform, with high accuracy, beamforming in a particular direction in the entire frequency band which the transmission signal can have.

Such beamforming can extend an object detectable distance in a particular direction in which object detection is needed. The beamforming described above can reduce a reflected signal from an unnecessary direction. Therefore, the accuracy of detecting the distance and/or the angle can be improved.

FIG.5is a diagram illustrating types of a detection distance of a radar implemented by the electronic device1according to the one embodiment.

As described above, the electronic device1according to the one embodiment is capable of clipping the object detection range and/or performing beamforming of the transmission waves. By employing at least one of clipping of the object detection range and beamforming of the transmission waves, the electronic device1is capable of defining a distance range in which an object can be detected on the basis of the transmission signal and the reception signal.

As illustrated inFIG.5, the electronic device according to the one embodiment is capable of performing detection of an object in a range r1, for example. The range r1illustrated inFIG.5may be a range in which detection of an object can be performed by an ultra-short range radar (USRR), for example. As illustrated inFIG.5, the electronic device1according to the one embodiment is also capable of performing detection of an object in a range r2, for example. The range r2illustrated inFIG.5may be a range in which detection of an object can be performed by a short-range radar (SRR), for example. As illustrated inFIG.5, the electronic device1according to the one embodiment is further capable of performing detection of an object in a range r3, for example. The range r3illustrated inFIG.5may be a range in which detection of an object can be performed by a mid-range radar (MRR), for example. As described above, the electronic device1according to the one embodiment is capable of performing detection of an object by appropriately switching the range to any of the range r1, the range r2, and the range r3, for example. In such radars having different detection distances, the distance measurement accuracy tends to decrease as the detection distance increases.

As described above, in the electronic device1according to the one embodiment, the electronic device may set the distance range in which detection of an object is performed on the basis of the transmission signal and the reception signal, in accordance with the object detection range.

Connections of the sensors5and the ECU50in the electronic device1is described next.

FIG.6is a diagram illustrating an example of connections of the sensors5and the ECU50in the electronic device according to the one embodiment.

FIG.6is a diagram schematically illustrating connections of the sensors5and the mobility device100illustrated inFIG.1, for example. The electronic device1according to the one embodiment includes the plurality of sensors5. As illustrated inFIG.6, the plurality of sensors5may include four sensors such as sensors5a,5b,5c, and5d, for example. When the plurality of sensors such as the sensors5a,5b,5c, and5d, for example, are not distinguished from each other in the electronic device1according to the one embodiment, the plurality of sensors are hereinafter simply referred to as “sensors5”. InFIG.2, an example in which only one sensor5is connected to the ECU50has been described. InFIG.6, an example in which four sensors5are connected to the ECU50is described.

As illustrated inFIG.6, in the one embodiment, each of the plurality of sensors5is connected to the ECU50. The ECU50may be connected to, for example, steering, gears, and/or the like used for causing the mobility device100to operate. The ECU50may be connected to another functional unit, for example, a brake and/or the like, used for causing the mobility device100to operate. The ECU50may be connected to any functional unit used for causing the mobility device100to operate, or to any functional unit controlled in the mobility device100. As illustrated inFIG.6, the ECU50may also be connected to a reporting unit90. In the one embodiment, these functional units can communicate various kinds of information via respective connections.

Each of the plurality of sensors5illustrated inFIG.6may have the same and/or similar configuration as that of the sensor5illustrated inFIG.2. Each of the plurality of sensors5illustrated inFIG.6may be connected to the ECU50and thus controlled individually by the ECU50.

The ECU50is capable of performing various kinds of detection such as detection of an object located around the mobility device100, on the basis of information output from the plurality of sensors5. The ECU50is also capable of controlling each of the plurality of sensors5when performing the various kinds of detection described above. In the one embodiment, the ECU50may function as a determination unit that determines a shift in orientation of at least any of the plurality of sensors5. Hereinafter, the ECU50may also be referred to as the “determination unit50” as appropriate. The shift in orientation of at least any of the plurality of sensors5, which is determined by the determination unit50, is further described below.

The ECU (Electronic Control Unit))50is capable of acquiring states of various functional units, such as steering and gears, of the mobility device100when the mobility device100is an automobile, for example. The ECU50may be connected to functional units such as a throttle and/or a brake in addition to steering and gears. The throttle, the brake, and/or the like of the mobility device100may be the same as and/or similar to those used for changing the speed of a common automobile, for example. In the one embodiment, the throttle, the brake, and/or like of the mobility device100may be operated by a driver or may be operated by the ECU50in automated driving.

The reporting unit90reports predetermined information to a driver or the like of the mobility device100. The reporting unit90may be any functional unit that stimulates at least any of the sense of hearing, the sense of sight, and the sense of touch of the driver of the mobility device100with sound, voice, light, text, video, vibration, and the like, for example. Specifically, the reporting unit90may be, for example, a buzzer, a speaker, a light-emitter such as an LED, a display such as an LCD, and a touch presenting unit such as a vibrator. In the one embodiment, the reporting unit90reports information on a detection result of an object located around the mobility device100to the driver or the like of the mobility device100, for example. For example, in the one embodiment, in response to detection of an object located around the mobility device100, the reporting unit90that reports visual information may report detection of the object to the driver of the mobility device through light emission or an indication. In addition, in the one embodiment, in response to detection of an object located around the mobility device100, the reporting unit90that reports auditory information may report detection of the object to the driver of the mobility device by sound or voice. Further, in the one embodiment, the reporting unit90may report information on a result of determining a shift in orientation of at least any of the plurality of sensors5to the driver or the like of the mobility device100, for example.

When the mobility device100is driven by a driver, the ECU50is capable of detecting states of various functional units of the mobility device100. For example, the ECU50is capable of detecting a turn angle (steering angle) of steering of the mobility device100. For example, the ECU50is capable of detecting which of forward traveling or backward traveling the gear of the mobility device100is operated in and which gear the gearbox is operated in. For example, the ECU50may also detect ON/OFF of a throttle and a brake of the mobility device100, degrees of the throttle and the brake, and so on.

In addition, as described above, when the mobility device100is driven by a driver, the reporting unit90may report information on a result of determining a shift in orientation of at least any of the plurality of sensors5. In this case, the control unit10and/or the ECU50may control the reporting unit90to report the information on the result of determining a shift in orientation of at least any of the plurality of sensors5.

On the other hand, when the mobility device100is driven by automated driving, the ECU50is capable of controlling various functional units of the mobility device100. Automated driving may refer to, for example, automated driving of levels1to5defined by the Japanese Government and the National Highway Traffic Safety Administration (NHTSA). For example, the ECU50may automatically control steering of the mobility device100in accordance with detection results obtained by the sensors5. The ECU50may automatically control the gears of the mobility device100(to travel forward/backward, for example) in accordance with detection results obtained by the sensors5. For example, the ECU50may automatically control the gear in which the gearbox is operated in, in accordance with detection results obtained by the sensors5. For example, the ECU50may also automatically control ON/OFF of a throttle and a brake of the mobility device100, degrees of the throttle and the brake, and so on in accordance with detection results obtained by the sensors5.

As described above, the electronic device1may include the ECU50that controls the operation of the mobility device100. In this case, the plurality of sensors5may supply information on a result of detecting an object located around the mobility device100to the ECU50. The ECU50may then determine a shift in orientation of at least any of the plurality of sensors5on the basis of the information supplied from at least any of the plurality of sensors5.

A shift in orientation of the plurality of sensors5of the electronic device1according to the one embodiment is described next.

In general, for example, when a sensor, such as a radar device, that detects a location of an object is installed on a mobility device such as an automobile, the sensor is calibrated at the time of shipment from a factory to adjust the sensor so that the correct location is to be detected, for example. For example, when a plurality of sensors are installed on a body of a mobility device such as an automobile, the sensors can be adjusted in terms of hardware such that the orientation in which (angle at which) each sensor is installed on the mobility device is adjusted. The sensors can also be calibrated in terms of software such that a relative positional relationship between an object detected by each of the sensors thus installed and the mobility device is correct. By performing adjustment and calibration in this way, information on the object located around the mobility device can be correctly grasped on the basis of detection results obtained by the plurality of sensors.

However, even if the adjustment and calibration are appropriately performed in the above-described manner, it is expected that the installed orientation (angle) of the sensor changes to an extent because the sensor receives a physical impact. For example, another mobility device or the like may come into contact with the sensor of the traveling mobility device, or the sensor may be scraped by the wall when the mobility device is parked. In such a case, the installed orientation (angle) of the sensor installed on the body or the bumper may change to an extent. In addition, even if the sensor does not directly receive a physical impact, it is expected that the installed orientation (angle) of the sensor may change to an extent because the sensor keeps receiving vibration while the mobility device travels over a certain distance, for example. If the installed orientation (angle) of the sensor changes because of any reason, the sensor is no longer able to correctly detect the location of the object.

To cope with such a circumstance, means for detecting the installed orientation (angle) of the sensor may be separately provided, and a change in installed orientation (angle) of tie sensor may be detected. However, the electronic device1according to the one embodiment determines, with the plurality of sensors, whether the installed orientations (angles) of the plurality of sensors are appropriate. Hereinafter, the installed orientation (angle) of a sensor may also be referred to as an “orientation of the sensor”. In addition, a change in installed orientation (angle) of the sensor, that is, a change in orientation of the sensor may also be referred to as a “shift in orientation of the sensor”. In addition, the one embodiment, a shift in orientation of the sensor may be a shift from the installed orientation of the sensor, for example.

An operation of the electronic device1according to the one embodiment is described next.

The electronic device1according to the one embodiment may include the plurality of sensors5. In the electronic device1according to the one embodiment, the ECU50may control the plurality of sensors5independently of each other. Control of the plurality of sensors5may refer to, for example, changing the object detection ranges of the sensors5or the transmission-wave reachable distances of the sensors5. Control of the plurality of sensors5may also refer to clipping the object detection ranges of the sensors5and/or controlling beamforming of transmission waves of the sensors5.

First, an example in which the electronic device1includes two sensors5as the plurality of sensors5is described.FIG.7is a diagram for describing an example of an operation of the electronic device1according to the one embodiment. When the electronic device1according to the one embodiment includes two sensors5, the two sensors5may be installed at two positions of the mobility device100as illustrated inFIG.7.

In the example illustrated inFIG.7, the sensor5ais installed in a left front portion of the mobility device100, and the sensor5bis installed in a right front portion of the mobility device100. In addition, as illustrated inFIG.7, the sensor5ain the left front portion of the mobility device100faces in a direction Dan, and the sensor5bin the right front portion of the mobility device100faces in a direction Dbn. Thus, in the electronic device1according to the one embodiment, the plurality of sensors5may be installed in predetermined orientations at different positions. Hereinafter, in the example illustrated inFIG.7, an object detection range of the sensor5amay also be referred to as a detection range Ta. In addition, an object detection range of the sensor5bmay also be referred to as a detection range Tb. As illustrated inFIG.7, the sensors5aand5bhave detection ranges having predetermined central angles with the directions Dan and Dbn at the center, respectively. In addition, in the example illustrated inFIG.7, it may be assumed that a transmission wave Ta is transmitted from the sensor5aand a transmission wave Tb is transmitted from the sensor5b.

In addition, in the electronic device1according to the one embodiment, the sensors5aand5bare installed such that the detection ranges of the respective sensors5partially overlap as illustrated inFIG.7. In the example illustrated inFIG.7, a portion of a right end (end in a clockwise direction) of the detection range Ta of the sensor5aand a portion of a left end (end in a counterclockwise direction) of the detection range Tb of the sensor5bhave an overlap. That is, both the sensor5aand the sensor5bcan detect an object in this overlapping portion of the detection range Ta and the detection range Tb. For example, an object P1illustrated inFIG.7is present at a location represented by coordinates (x1, y1). In this case, the object P1is located in the detection range Ta of the sensor5aand also in the detection range Tb of the sensor5b. Thus, both the sensor5aand the sensor5bcan detect the object P1. As described above, in the electronic device1according to the one embodiment, a first sensor5aand a second sensor5bmay be installed in predetermined orientations such that an object detection range Ta of the first sensor5aand an object detection range Tb of the second sensor5bpartially overlap.

As illustrated inFIG.7, in the electronic device1according to the one embodiment, after the sensors5aand5bare installed in correct orientations, calibration of the sensors5may be then performed. Specifically, for example, calibration is performed such that the locations detected for the object P1by the sensor5aand the sensor5bindicate the same location in the electronic device1as illustrated inFIG.7. That is, for example, suppose that the coordinates of the object P1detected by the sensor5aindicate the point (x1, y1) in the front direction of the mobility device100. In this case, calibration is performed such that the coordinates of the object P1detected by the sensor5balso indicate the point (x1, y1) in the front direction of the mobility device100. If such calibration is performed, the object P1is detected by both the sensor5aand the sensor5bto be at the same location (x1, y1) in the electronic device1.

The adjustment of the orientations of the sensors5and the calibration of the sensors5illustrated inFIG.7may be performed, for example, at the time of shipment of the mobility device100from a factory or at the time of various inspections such as a vehicle inspection. In this case, for example, a corner reflector or the like having a high reflectivity may be used as the object P1. The object P1such as a corner reflector may be disposed at a known point (x1, y1), and may be detected by the sensors5aand5b. In this manner, calibration may be performed.

On the other hand, the timing at which the adjustment of the orientations of the sensors5and the calibration of the sensors5illustrated inFIG.7are performed is not limited to at the time of shipment of the mobility device100from a factory or at the time of various inspections, and may be performed at another timing. For example, the adjustment of the orientations of the sensors5and the calibration of the sensors5may be performed in response to the sensors5aand5bdetecting an object suitable for the object P1while the mobility device100is traveling normally. The timing at which the adjustment of the orientations of the sensors5and the calibration of the sensors5illustrated inFIG.7are performed may be various timings. For example, as such a timing, other cases such as a case where the mobility device100has traveled over a certain distance, a case where the mobility device100has detected a vibration of a predetermined value or greater with an acceleration sensor and/or a gyrosensor, a case where a predetermined time has passed from the previous calibration, a case where a user inputs a calibration start instruction, and a case where the mobility device100has detected an acceleration or speed of a predetermined value or greater with a velocity sensor and/or a gyrosensor may be combined in any manner. The case where the mobility device100has detected a vibration of a predetermined value or greater with an acceleration sensor and/or a gyrosensor may include, for example, a case where shaking of a predetermined frequency or higher has been detected.

After the adjustment of the orientations of the sensors5and the calibration of the sensors5are performed as illustrated inFIG.7, the electronic device1can detect an object located around the mobility device100during normal traveling, for example. That is, the electronic device detects an object located around the mobility device100, and reports the detection to a driver or the like of the mobility device100via the reporting unit90or may use the detection for the mobility device100.

As described above, after the adjustment of the orientations of the sensors5and the calibration of the sensors5are performed, the orientations of the sensors5may shift because of some reasons. For example, suppose that the sensor5acomes into contact with something and consequently the orientation of the sensor5ais shifted slightly in a circumstance illustrated inFIG.7.

FIG.8is a diagram illustrating a state in which the orientation of the sensor5ais shifted slightly. For example, suppose that the sensor5acomes into contact with something and consequently the orientation of the sensor5ais shifted counterclockwise by φ1as illustrated inFIG.8. In this case, the orientation of the sensor5ais shifted from the direction Dan to a direction Dan′. In response to this, the detection range of the sensor5ais also shifted from the detection range Ta to a detection range Ta′ as illustrated inFIG.8.

As inFIG.7, it is assumed also inFIG.8that the object P1is at the location (x1, y1) in the front direction of the mobility device100. In such a circumstance, detecting the object P1with the sensor5aand the sensor5bis discussed. As illustrated inFIG.8, the locations detected for the object P1by the sensor5aand the sensor5bare not the same location in the electronic device1. In the detection range Tb, the sensor5bstill detects the object P1to be at the point (x1, y1). On the other hand, since the detection range Ta is shifted to the detection range Ta′, the sensor5adetects the object P1to be at a location P1′. Here, it is assumed that coordinates of the location P1′ are coordinates (x1′, y1°). The location of the object detected by the sensor5awhose orientation is shifted is

identified on the basis of the coordinates allocated in the detection range Ta′. The object P1that is actually at the location of the coordinates (x1, y1) is detected at the right end (end in the clockwise direction) of the detection range Ta′. This detection range Ta′ corresponds to the detection range Ta before the orientation of the sensor5ais shifted. Thus, the sensor5adetects the object P1to be at the right end (end in the clockwise direction) of the detection range Ta, that is, at the location P1′ (coordinates (x1′, y1°)).

As described above, when the orientation of either the sensor5aor the sensor5bis shifted, even if the locations are detected for the same object P1in the electronic device1, the locations are not the same. From the above, in the one embodiment, when the sensor5aand the sensor5bdetect locations for the same object P1, if the locations (for example, coordinates) are not the same, it may be determined that the orientation of one of the sensor5aand the sensor5bis shifted. Conversely, in the one embodiment, when the sensor5aand the sensor5bdetect locations for the same object P1, if the locations (for example, coordinates) are substantially the same, it may be determined that the orientations of the sensor5aand the sensor5bare not shifted. Such a determination may be made by the ECU (determination unit)50, for example. In this case, it is impossible to determine which of the sensor5aand the sensor5bis shifted but it is possible to determine that the orientation of one of the sensor5aand the sensor5bis shifted. An operation for determining which of the sensor5aand the sensor5bis shifted when the orientation of one of the sensor5aand the sensor5bis shifted is further described later.

FIG.9is a flowchart for describing an operation for determining whether the orientation of either of the two sensors is shifted in the electronic device1as described inFIG.8. It is assumed that the adjustment of the orientations of the plurality of sensors5and the calibration of the plurality of sensors5as described above have been completed at the time point when the operation Illustrated inFIG.9starts. In addition, the operation of the electronic device1illustrated inFIG.9may be controlled by the control unit10and/or the ECU (determination unit)50, for example. The description is given below on the assumption that the operation of the electronic device1illustrated inFIG.9is controlled by the ECU50.

In response to the start of the operation illustrated inFIG.9, the ECU50detects an object with a first sensor (for example, the sensor5a) of the electronic device1(step S11). Then, the ECU50detects the object with a second sensor (for example, the sensor5b) of the electronic device1(step S12).

Then, the ECU50determines whether locations (for example, coordinates) detected for the same object (for example, the object P1) by the first and second sensors are separate by a predetermined distance or greater (step S13). To determine whether the locations for the same object are separate by the predetermined distance or greater in step S13, a distance at which the locations can be regarded as being the same location may be set and stored in, for example, the storage unit40or the like in advance. The distance at which the locations can be regarded as being the same location may be determined on the basis of various factors including the object detection accuracy of the electronic device1. For example, if the distance between the locations detected for the same object by the sensor5aand the sensor5bis equal to or less than 5 cm, it may be regarded that the sensor5aand the sensor5bdetect the same object to be at the same location. In this case, if the distance between the locations detected for the same object by the sensor5aand the sensor5bexceeds 5 cm, it may be regarded that the sensor5aand the sensor5bdetect the same object to be at different locations.

If it is determined in step S13that the locations for the same object are not separate by the predetermined distance or greater, the ECU50determines that neither the first sensor nor the second sensors is shifted (step S14). On the other hand, if it is determined in step S13that the locations for the same object are separate by the predetermined distance or greater, the ECU50determines either the first sensor or the second sensors is shifted (step S15).

As described above, in the one embodiment, the determination unit50may determine a shift in orientation of at least any of the plurality of sensors5on the basis of object detection results obtained by the plurality of sensors5. More specifically, the determination unit50may determine whether an orientation of at least any of the plurality of sensors5is shifted from the installed orientation on the basis of the locations detected for an object by the plurality of sensors5. The determination unit50may determine the shift in orientation of either the first sensor5aor the second sensor5bon the basis of detection results of the same object obtained by the first sensor5aand the second sensor5b. For example, the determination unit50may determine that the orientation of either the first sensor5aor the second sensor5bis shifted if the locations detected for the same object by the first second sensor5aand the second sensor5bare separate by a predetermined distance or greater.

The electronic device1according to the one embodiment can determine, with the plurality of sensors, whether the installed orientations (angles) of the plurality of sensors are appropriate. That is, the electronic device1according to the one embodiment need not use, for example, another functional unit for detecting the installed states of the plurality of sensors in determining whether the installed orientations (angles) of the sensors are appropriate.

The electronic device1according to the one embodiment is capable of determining whether the installed states of the plurality of sensors are appropriate in the electronic device that performs detection of an object by using the sensors. Thus, the electronic device1according to the one embodiment can improve the convenience of the electronic device including the plurality of sensors that receive a reflected wave that is a transmission wave transmitted and reflected off a predetermined object.

A case where the sensor5acomes into contact with something in the state illustrated inFIG.7, for example, and consequently the orientation of the sensor5ais shifted by a greater degree than that in the state illustrated inFIG.8is described next.

FIG.10is a diagram illustrating a state in which the orientation of the sensor5ais shifted to an extent. For example, suppose that the sensor5acomes into contact with something and consequently the orientation of the sensor5ais shifted counterclockwise by φ2as illustrated inFIG.10. In this case, the orientation of the sensor5as shifted from the direction Dan to a direction Dan′. In response to this, the detection range of the sensor5ais also shifted from the detection range Ta to a detection range Ta′ as illustrated inFIG.10.

It is assumed inFIG.10that an object Q1is at a location (x11, y11) on a slightly left side of the front direction of the mobility device100. In such a circumstance, detecting the object Q1with the sensor5aand the sensor5bis discussed. As illustrated inFIG.10, the location of the object Q1is not in the detection range Tb of the sensor5b. Thus, the sensor5bis unable to detect the object Q1in the detection range Tb. On the other hand, since the detection range Ta is shifted to the detection range Ta′, the sensor5adetects the object Q1to be at a location Q1′. Here, it is assumed that coordinates of the location Q1′ are (x11′, y11′). The location of the object detected by the sensor5awhose orientation is shifted is identified on the basis of the coordinates allocated in the detect ion range Ta′. The object Q1that is actually at the location of the coordinates (x11, y11) is detected to be near the right end (end in the clockwise direction) of the detect ion range Ta′. This detection range Ta′ corresponds to the detection range Ta before the orientation of the sensor5ais shifted. Thus, the sensor5adetects the object Q1to be near the right end (end in the clockwise direction) of the detection range Ta, that is, at the location Q1′ (coordinates (x11′, y11′)).

As illustrated inFIG.10, the location Q1′ is a location in the detection range Tb of the sensor5band in the detection range Ta of the sensor5abefore the orientation is shifted. That is, the location Q1′ is in a partially overlapping region of the object detection ranges (Ta and Tb) of the sensors5aand5bwhen the sensors5aand5bare installed in predetermined orientations (in the directions Dan and Dbn) (before the shifting). Thus, if the orientations of the sensors5aand5bare not shifted from the orientations (the directions Dan and Dbn) in which the sensors5aand5bare installed, both the sensors5aand5bdetect the object to be at the location Q1′. However, as described above, in this case, the sensor5adetects the object Q1(to be at the location Q1′ in the electronic device1) but the sensor5bdoes not detect the object Q1.

As described above, there may be a case where an object located in a partially overlapping region of the object detection ranges (Ta and Tb) of the sensors5aand5bis detected by one of the sensors5but is not detected by the other of the sensors5. In such a case, it may be determined that the orientation of one of the sensors5aand5bis shifted. Such a determination may be made by the ECU (determination unit)50, for example. In addition, when the object located in the partially overlapping region of the object detection ranges (Ta and Tb) of the sensors5aand5bis detected by both the sensors5aand5b, the operation described inFIGS.8and9may be performed. Also in this case, it is impossible to determine which of the sensor5aand the sensor5bis shifted but it is possible to determine that the orientation of one of the sensor5aand the sensor5bis shifted. An operation for determining which of the sensor5aand the sensor5bis shifted when the orientation of one of the sensor5aand the sensor5bis shifted is further described later.

FIG.11flowchart for describing an operation for determining whether the orientation of either of the two sensors is shifted in the electronic device1as described inFIG.10. It is assumed that the adjustment of the orientations of the plurality of sensors5and the calibration of the plurality of sensors5as described above have been completed at the time point when the operation illustrated inFIG.11starts. In addition, tie operation of the electronic device1illustrated inFIG.11may be controlled by the control unit10and/or the ECU (determination unit)50, for example. The description is given below on the assumption that the operation of the electronic device1illustrated inFIG.11is controlled by the ECU50.

As in the operation illustrated inFIG.9, the ECU50performs the processing of steps S11and S12in response to the start of the operation illustrated inFIG.11.

Then, the ECU50determines whether only one of the first and second sensors5has detected an object in a detection range in which the detection ranges of the first and second sensors5partially overlap originally (for example, at the time of installation of the sensors5) (step S23). Only one of the first and second sensors5detecting an object in step S23may refer to, for example, a state in which the second sensor5does not detect the object detected by the first sensor5. In addition, only one of the first and second sensors5detecting an object in step S23may refer to, for example, a state in which the first sensor5does not detect the object detected by the second sensor5.

If the sensor5that detects the object is not only one of the sensors5in step S23and if it is determined that the locations for the same object are not separate by a predetermined distance or greater, the ECU50determines that neither the first sensor nor the second sensor is shifted (step S14). The case where the sensor5that detects the object is not only one of the sensors5may be, for example, the case where both the first and second sensors detect the object. In addition, the case where the sensor5that detects the object is not only one of the sensors5may be, for example, a case where the object detected by one of the first and second sensors5is detected by the other. On the other hand, if only one of the sensors5detects the object in step S23, the ECU50determines that either the first sensor or the second sensor is shifted (step S15).

As described above, in the one embodiment, the determination unit50may determine a shift in orientation of at least any of the plurality of sensors5on the basis of object detection results obtained by the plurality of sensors5. More specifically, the determination unit50may determine whether an orientation of at least any of the plurality of sensors5is shifted from the installed orientation on the basis of the locations detected for an object by the plurality of sensors5. The determination unit50may determine the shift in orientation of either the first sensor5aor the second sensor5bon the basis of detection results of the same object obtained by the first sensor5aand the second sensor5b. For example, a region where the object detection ranges of the sensors partially overlap when the first sensor5aand the second sensor5bare installed in the predetermined orientations is referred to an overlapping region. In this case, if the object detected by one of the first sensor5aand the second sensor5bis not detected by the other in the overlapping region, the determination unit50may determine that the orientation of either the first sensor5aor the second sensor5bis shifted.

The electronic device1according to the one embodiment can determine, with the plurality of sensors, whether the installed orientations (angles) of the plurality of sensors are appropriate. That is, the electronic device1according to the one embodiment no longer needs, for example, another functional unit for detecting the installed states of the plurality of sensors in determining whether the installed orientations (angles) of the sensors are appropriate.

The electronic device1according to the one embodiment is capable of determining whether the installed states of the plurality of sensors are appropriate in the electronic device that performs detection of an object by using the sensors. Thus, the electronic device1according to the one embodiment can improve the convenience of the electronic device including the plurality of sensors that receive a reflected wave that is a transmission wave transmitted and reflected off a predetermined object.

An example in which the electronic device1includes three or more sensors5as the plurality of sensors5is described next. By including three or more sensors5, the electronic device1according to the one embodiment can determine which of the sensors5is shifted in orientation when it is determined that the orientation of either of two sensors5is shifted.

FIG.12is a diagram for describing an example of an operation of the electronic device1according to the one embodiment. When the electronic device1according to the one embodiment includes four sensors5, the four sensors5may be installed at four positions of the mobility device100as illustrated inFIG.12.

In the example illustrated inFIG.12, two more sensors5may be installed on the mobility device100illustrated inFIG.7. Thus, more detailed description of the sensor installed in the left front portion of the mobility device100and the sensor5binstalled in the right front portion of the mobility device100is omitted inFIG.12.

In the example illustrated inFIG.12, the sensor5cis installed in a right rear portion of the mobility device100, and the sensor5dis installed in a left rear portion of the mobility device100. In addition, as illustrated inFIG.12, the sensor5cin the right rear portion of the mobility device100faces in a direction Dcn, and the sensor5din the left rear portion of the mobility device100faces in a direction Ddn. Thus, in the electronic device1according to the one embodiment, the plurality of sensors5may be installed in predetermined orientations at different positions. Hereinafter, in the example illustrated inFIG.12, an object detection range of the sensor5cmay also be referred to as a detection range Tc. In addition, an object detection range of the sensor5dmay also be referred to as a detection range Td. As illustrated inFIG.12, the sensors5cand5dhave detection ranges having predetermined central angles with the directions Dcn and Ddn at the center, respectively. In addition, in the example illustrated inFIG.12, it may be assumed that a transmission wave Tc transmitted from the sensor5cand a transmission wave Td is transmitted from the sensor5d.

In the electronic device1according to the one embodiment, the sensors5band5care installed such that the detection ranges of the respective sensors5partially overlap as illustrated inFIG.12. In the example illustrated inFIG.12, a portion of a right end (end in a clockwise direction) of the detection range Tb of the sensor5band a portion of a left end (end in a counterclockwise direction) of the detection range Tc of the sensor5chave an overlap. That is, both the sensor5band the sensor5ccan detect an object in this overlapping portion of the detection range Tb and the detection range Tc. For example, an object P2illustrated inFIG.12is present at a location represented by coordinates (x2, y2). In this case, the object P2is located in the detection range Tb of the sensor5band also in the detection range Tc of the sensor5c. Thus, both the sensor5band the sensor5ccan detect the object P2.

In the electronic device1according to the one embodiment, the sensors5cand5dare installed such that the detection ranges of the respective sensors5partially overlap as illustrated inFIG.12. In the example illustrated inFIG.12, a portion of a right end (end in a clockwise direction) of the detection range Tc of the sensor5cand a portion of a left end (end in a counterclockwise direction) of the detection range Td of the sensor5dhave an overlap. That is, both the sensor5cand the sensor5dcan detect an object in this overlapping portion of the detection range Tc and the detection range Td. For example, an object P3illustrated inFIG.12is present at a location represented by coordinates (x3, y3). In this case, the object P3is located in the detection range Tc of the sensor5cand also in the detection range Td of the sensor5d. Thus, both the sensor5cand the sensor5dcan detect the object P3.

In the electronic device1according to the one embodiment, the sensors5dand5aare installed such that the detection ranges of the respective sensors5partially overlap as illustrated inFIG.12. In the example illustrated inFIG.12, a portion of a right end (end in a clockwise direction) of the detection range Td of the sensor5dand a portion of a left end (end in a counterclockwise direction) of the detection range Ta of the sensor5ahave an overlap. That is, both the sensor5dand the sensor5acan detect an object in this overlapping portion of the detection range Td and the detection range Ta. For example, an object P4illustrated inFIG.12is present at a location represented by coordinates (x4, y4). In this case, the object P4is located in the detection range Td of the sensor5dand also in the detection range Ta of the sensor Thus, both the sensor5dand the sensor5acan detect the object P4.

As described above, in the electronic device1according to the one embodiment, the plurality of sensors5may include the first sensor5a, the second sensor5a, and the third sensor5c(and/or5d). In addition, the third sensor5c(or5d) may be installed in a predetermined orientation such that the object detection range (Ta or Tb) of the first sensor5aor the second sensor5band the object detection range Tc (or Td) of the third sensor5c(or5d) partially overlap.

As illustrated inFIG.12, in the electronic device according to the one embodiment, after the sensors5a,5b,5c, and5dare installed in correct orientations, calibration of the individual sensors5may be then performed in a manner that is same as and/or similar to that described inFIG.7.

As described above, after the adjustment of the orientations of the sensors5and the calibration of the sensors5are performed, the orientations of the sensors5may shift because of some reasons. For example, suppose that the sensor5acomes into contact with something and consequently the orientation of the sensor5ais shifted slightly in a circumstance illustrated inFIG.12.

FIG.13is a diagram illustrating a state in which the orientation of the sensor5ais shifted slightly. For example, suppose that the sensor5acomes into contact with something and consequently the orientation of the sensor5ais shifted counterclockwise by φ1as illustrated inFIG.13. In this case, the orientation of the sensor5ais shifted from the direction Dan to the direction Dan′. In response to this, the detection range of the sensor5ais also shifted from the detection range Ta to the detection range Ta′ as illustrated inFIG.13.FIG.13illustrates a state in which the same circumstance as that illustrated inFIG.8has occurred in the mobility device100on which the sensors5a,5b,5c, and5dare installed. Thus, the description that is same as and/or similar to the description inFIG.8is omitted as appropriate.

As described inFIGS.8and9, when two sensors such as the sensors5aand5bare installed, it is possible to determine that the orientation of one of the sensors5aand5bis shifted. However, in the operation described inFIGS.8and9, it is impossible to determine which of the sensors5aand5bis shifted. In contrast, the electronic device1including three or more sensors5as illustrated inFIG.13is capable of determining which of the sensors5aand5bis shifted when the orientation of one of the sensors5aand5bis shifted. Such an operation is described below.

As illustrated inFIG.13, both the sensors5band5cdetect the same object P2to be at the same location (coordinates (x2, y2)). Thus, by applying the operation described inFIGS.8and9to the sensors5band5c, it may be determined that neither the sensor5bnor the sensor5cis shifted. In addition, as illustrated inFIG.13, both the sensors5cand5ddetect the same object P3to be at the same location (coordinates (x3, y3)). Thus, by applying the operation described inFIGS.8and9to the sensors5cand5d, it may be determined that neither the sensor5cnor the sensor5dis shifted.

On the other hand, as illustrated inFIG.13, the locations detected for the object P4by the sensor5dand the sensor5aare not the same location in the electronic device1. In the detection range Td, the sensor5ddetects the object P4to be at the point (x4, y4). In contrast, since the detection range Ta is shifted to the detection range Ta′, the sensor5adetects the object P4to be at a location P4′. Here, it is assumed that coordinates of the location P4′ are coordinates (x4′, y4′). The location of the object detected by the sensor5awhose orientation is shifted is identified on the basis of the coordinates allocated in the detection range Ta′. The object P4that is actually at the location of the coordinates (x4, y4) is detected to be near the left end (end in the counterclockwise direction) of the detection range Ta′. This detection range Ta′ corresponds to the detection range Ta before the orientation of the sensor5ais shifted. Thus, the sensor5adetects the object P4to be near the left end (end in the counterclockwise direction) of the detection range Ta, that is, at the location P4° (coordinates (x4′, y4′)). Thus, by applying the operation described inFIGS.8and9to the sensors5dand5a, it may be determined that either the sensor5dor the sensor5ais shifted.

The above results are summarized as follows. That it is determined that either the sensor5aor the sensor5bis shifted. In addition, it is determined that neither the sensor5bnor the sensor5cis shifted. In addition, it is determined that neither the sensor5cnor the sensor5dis shifted. In addition, it is determined that either the sensor5dor the sensor5ais shifted. From these results, the determination unit50can determine that shifted sensor5is the sensor5a.

In addition, for example, only the sensor5camong the sensors5cand5dis installed, it may be determined that the orientation of the sensor5bis not shifted if both the sensors5band5cdetect the same object P2to be at the same location. In addition, for example, only the sensor5damong the sensors5cand5dis installed, it may be determined that the orientation of the sensor5ais shifted if the sensors5dand5adetect the same object P2to be at different locations.

As described above, in the electronic device1according to the one embodiment, the determination unit50may perform processing below when the determination unit50determines that the orientation of either the first sensor5aor the second sensor5bis shifted. That is, the determination unit50may determine which of the first sensor5aand the second sensor5bis shifted in orientation on the basis of detection results of the same object obtained by the first sensor5aor the second sensor5band the third sensor5c(or5d).

FIG.14is a flowchart for describing an operation for determining which of the two sensors such as the sensors5aand5bis shifted in orientation in the electronic device1as described inFIG.13. The time point when the operation illustrated inFIG.14starts may be, for example, the time point when it is determined that either of the two sensors5such as the sensors5aand5b, for example, is shifted as in step S15ofFIGS.9and11, for example. The operation of the electronic device1illustrated inFIG.14may be controlled by the control unit10and/or the ECU (determination unit)50, for example. The description is given below on the assumption that the operation of the electronic device1illustrated inFIG.14is controlled by the ECU50.

In response to the start of the operation illustrated inFIG.14, the ECU50detects an object with the third sensor (for example, the sensor5cor5d) of the electronic device1(step S31).

Then, the ECU50determines whether the location of the object detected by the first sensor5aand the location of the object detected by the third sensor5cor5das the same object as the object detected by the first sensor5aare separate by a predetermined distance or greater (step S32). The operation for determining whether the object is separate by a predetermined distance or greater in step S32may be performed in a manner that is the same as and/or similar to that in step S13inFIG.9.

If it is determined in step S32that the locations detected for the object by the two sensors5are separate by the predetermined distance or greater, the ECU50may determine that the orientation of the first sensor5ais shifted (step S33).

On the other hand, if it is determined in step S32that the locations detected for the object by the two sensors5are not separate by the predetermined distance or greater, the ECU50may perform an operation of step S34. In step S34, the ECU50determines whether the location of the object detected by the second sensor5band the location of the object detected by the third sensor5cor5das the same object as the object detected by the second sensor5bare separate by a predetermined distance or greater (step S34). The operation for determining whether the object is separate by a predetermined distance or greater in step S34may be performed in a manner that is the same as and/or similar to that in step S13inFIG.9.

If it is determined in step S34that the locations detected for the object by the two sensors5are separate by the predetermined distance or greater, the ECU50may determine that the orientation of the second sensor5bis shifted (step S35).

As described above, by including three or more sensors5, the electronic device1can determine which of the sensors5aand5bis shifted when the orientation of one of the sensors5aand5bis shifted.

An example in which two sensors5are shifted in the same direction by substantially the same degree by coincidence when the electronic device1includes three or more sensors5as the plurality of sensors5is described next.

FIG.15is a diagram illustrating a state in which the orientation of the sensor5ais shifted slightly as illustrated inFIG.13and the orientation of the sensor5bis also shifted slightly. It is assumed that, for example, the sensor5acomes into contact with something and consequently the orientation of the sensor5ais shifted counterclockwise by φ1and, for example, the sensor5bcomes into contact with something and consequently the orientation of the sensor5bis also shifted counterclockwise by p1as illustrated inFIG.15. In this case, the orientation of the sensor5ais shifted from the direction Dan to the direction Dan′. In response to this, the detection range of the sensor5ais also shifted from the detection range Ta to the detection range Ta′ as illustrated inFIG.15. In addition, in this case, the orientation of the sensor5bis shifted from the direction Dbn to a direction Dbn′. In response to this, the detection range of the sensor5bis also shifted from the detection range Tb to a detection range Tb′ as illustrated inFIG.15.

As inFIG.13, it is assumed also inFIG.15that the object P1is present at the location (x1, y1) in the front direction of the mobility device100. In such a circumstance, detecting the object P1with the sensor5aand the sensor5bis discussed. Since the detection range Ta is shifted to the detection range Ta′, the sensor5adetects the object P1to be at the location P1′ as illustrated inFIG.15. Here, it is assumed that coordinates of the location P1′ are coordinates (x1′, y1′). Since the detection range Tb is shifted to the detection range Tb′, the sensor5balso detects the object P1to be at the location P1′. That is, in this case, the sensors5aand5bare shifted in the same direction by the same angle by coincidence. In such a case, even if the electronic device1performs the operation ofFIGS.8and9, for example, it is not determined that the orientation of either the sensor5aor the sensor5bis shifted.

However, as in the state illustrated inFIG.13, the sensor5ddetects the object P4to be located at the point (x4, y4) in the detection range Td in the state illustrated inFIG.15. In contrast, since the detection range Ta is shifted to the detection range Tag, the sensor5adetects the object P4to be at the location P4′. Likewise, the sensor5cdetects the object P2to be at the point (x2, y2) in the detection range Tc in the state illustrated inFIG.15. In contrast, since the detection range Tb is shifted to the detection range Tb′, the sensor5bdetects the object P2to be at the location P2′. In such a case, it can be determined that both the sensors5aand5bare shifted in the same direction by the same degree.

As described above, in the electronic device1according to the one embodiment, the determination unit50may perform processing below when the locations detected for a same first object by the first sensor5aand the second sensor5bare within a predetermined distance. That is, the determination unit50may determine whether the orientations of both the first sensor5aand the second sensor5bare shifted on the basis of detection results of a same second object obtained by the first sensor5aor the second sensor5band the third sensor5c(or5d).

FIG.16is a flowchart for describing an operation for determining that two sensors such as the sensors5aand5bare shifted in the same direction by the same degree in the electronic device1as illustrated inFIG.15.

The time point when the operation illustrated inFIG.16starts may be, for example, the time point when the adjustment of the orientations of the plurality of sensors5and the calibration of the plurality of sensors5are completed as in the operation illustrated inFIGS.9and11, for example.

In response to the start of the operation illustrated inFIG.16, the ECU50detects an object with the first sensor (for example, the sensor5a) of the electronic device (step S11). Then, the ECU50detects the object with the second sensor (for example, the sensor5b) of the electronic device1(step S12).

Then, the ECU50determines whether locations (for example, coordinates) detected for the same object (for example, the object P1) by the first and second sensors are separate by a predetermined distance or greater (step S13). To determine whether the locations for the same object are separate by the predetermined distance or greater in step S13, a distance at which the locations can be regarded as being the same location may be set and stored in, for example, the storage unit40or the like in advance. The distance at which the locations can be regarded as being the same location may be determined on the basis of various factors including the object detection accuracy of the electronic device1. For example, if the distance between the locations detected for the same object by the sensor5aand the sensor5bis equal to or less than 5 cm, it may be regarded that the sensor5aand the sensor5bdetect the same object to be at the same location. In this case, if the distance between the locations detected for the same object by the sensor5aand the sensor5bexceeds 5 cm, it may be regarded that the sensor5aand the sensor5bdetect the same object to be at different locations.

If it is determined in step S13that the locations for the same object are separate by the predetermined distance or greater, the ECU50determines one of the first sensor and the second sensors is shifted (step S15). In this case, the operation illustrated inFIG.14may be performed.

On the other hand, if it is not determined in step S13that the locations for the same object are separate by the predetermined distance or greater, the ECU50detects the object with the third sensor5c(or5d) (step S41). The ECU50determines whether the location of the object detected by the third sensor5c(or5d) in step S41and the location of the object detected by the first sensor5aand the second sensor5bas the same object as the object detected by the third sensor5care separate by a predetermined distance or greater (step S42). The operation for determining whether the object is separate by the predetermined distance or greater in step S42may be performed in a manner that is the same as and/or similar to that in step S13inFIG.9.

If it is determined in step S42that the locations for the object are separate by the predetermined distance or greater, the ECU50may determine that the orientations of the first sensor5aand the second sensor5bare shifted (step S43).

As described above, by including three or more sensors5, the electronic device1can determine whether the two sensors5are shifted in the same direction by the same degree by coincidence.

An operation performed when the orientation of the sensor5is shifted in the electronic device1is described next.

In the electronic device1according to the one embodiment, if it is determined that the orientation of the sensor5is shifted and if the shift is a degree correctable through calibration, the shift may be corrected by performing calibration, for example. On the other hand, in the electronic device1according to the one embodiment, if it is determined that the orientation of the sensor5is shifted and if the shift is a degree uncorrectable through calibration, the shift of the sensor5may be reported to a user by the reporting unit90, for example.

FIG.17is a flowchart for describing an operation performed when the orientation of the sensor5is shifted in the electronic device1. The time point when the operation illustrated inFIG.17starts may be the time point when the determination unit50determines that the orientation of any of the sensors5is shifted. For example, the time point when the operation illustrated inFIG.17starts may be after step S15ofFIGS.9and11, after steps S33and S35ofFIG.14, and after step S43ofFIG.16.

In response to the start of the operation illustrated inFIG.17, the ECU50determines whether the shift of the sensor5determined to be shifted is equal to or greater than a predetermined degree (step S51). The predetermined degree of shift to be compared with the shift of the sensor5in step S51may be stored in advance in the storage unit40or the like as a degree of shift for which the sensor5can be calibrated in the electronic device1, for example.

If it is determined in step S51that the shift of the sensor5is not equal to or greater than the predetermined degree, the ECU50performs calibration of the location of the object detected by the sensor5(step S52). On the other hand, if it is determined in step S51that the shift of the sensor5is equal to or greater than the predetermined degree, the ECU50outputs information (report information) indicating that the sensor5is shifted, from the reporting unit90, for example (step S53).

In step S53, the information indicating that the sensor5is shifted may be, for example, at least any of excessive information based on voice or sound, visual information such as an indication, and sensing information such as a vibration. In addition, the information indicating that the sensor5is shifted may be, for example, information for prompting the driver or the like of the mobility device100to fix or adjust the sensor5. As a result of the report information being output in step S53, for example, the driver or the like of the mobility device100can recognize the orientation of any of the sensors5is shifted.

As described above, in the electronic device1according to the one embodiment, the determination unit50may perform calibration of the location of the object detected by at least any of the plurality of sensors5when determining that the shift in orientation of any of the plurality of sensors5is within a predetermined degree. In addition, in the electronic device1according to the one embodiment, the determination unit50may output predetermined report information, for example, from the reporting unit90when determining that the shift in orientation of any of the plurality of sensors5exceeds the predetermined degree.

While the present disclosure has been described on the basis of the various drawings and the embodiment, it should be noted that a person skilled in the art can easily make various variations or corrections on the basis of the present disclosure. Therefore, it should 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. A plurality of 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 on the basis of the present disclosure. Accordingly, 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, a plurality of functional units, means, steps, or the like may be combined to one or may be divided. In addition, 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.

The embodiment described above is not limited to implementation as the electronic device1. For example, the embodiment described above may be implemented as a method for controlling a device such as the electronic device1. For example, the embodiment described above may be implemented as a program for controlling a device such as the electronic device1.

In the embodiment described above, the ECU50of the electronic device1determines, as a shift in orientation of the sensor5, a shift in a horizontal direction that is parallel to an KY plane illustrated inFIG.12, for example. However, the ECU50of the electronic device1according to the one embodiment may determine, as a shift in orientation of the sensor5, a shift in a direction that is perpendicular to the KY plane illustrated inFIG.12, for example.

REFERENCE SIGNS LIST

1electronic device5sensor10control unit11distance FFT processing unit12velocity FF1processing unit13angle-of-arrival estimating unit14object detecting unit15detection range determining unit16parameter setting unit20transmission unit21signal generating unit22synthesizer23phase control unit24amplifier25transmission antenna30reception unit31reception antenna32LNA33mixer34IF unit35AD conversion unit40storage unit50ECU (determination82steering84gears90reporting unit100mobility device200object