MEASUREMENT DEVICE, MEASUREMENT METHOD, AND COMPUTER PROGRAM PRODUCT

A measurement device according to the present disclosure includes a memory and a processor coupled to the memory. The processor is configured to: transmit a distance-detecting radiowave from an antenna; detect a distance between the antenna and a vehicle based on a first reception radiowave received by the antenna, the first reception radiowave being a reception radiowave obtained by the antenna receiving a reflected wave of a distance-detecting radiowave reflected by the vehicle on which a communication system configured to transmit a measurement target radiowave is mounted; perform drive control on at least one of the antenna and the vehicle so that the detected distance reaches a set distance larger than 0; and derive, when the detected distance reaches the set distance, communication performance of the communication system based on a second reception radiowave that is the measurement target radiowave received by the antenna.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-115485, filed on Jul. 13, 2021, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a measurement device, a measurement method, and a computer program product.

BACKGROUND

Conventionally, there is known a system that receives, by an antenna, a radiowave emitted from a communication system mounted on a target such as a mobile phone or a vehicle and derives communication performance of the communication system on the basis of the reception radiowave that has been received (see, for example, JP No. 2019-505768 A). For example, a target is placed on a turntable or the like, and the target is rotated while a distance between an antenna and the target is kept constant, whereby a reception radiowave is acquired at each position around the target.

Communication systems mounted on targets have a plurality of wireless communication schemes such as long-distance wireless communication and short-distance wireless communication. In order to receive a radiowave transmitted from a communication system that transmits a radiowave by short-distance wireless communication or a radiowave of weak intensity, it is necessary to perform measurement by bringing an antenna close to a target. However, in the related art, there may be cases where the antenna collides with the target at the time of measurement. That is, in the related art, it is difficult to avoid contact between an antenna and a target to satisfactorily measure the communication performance of a communication system.

An object to be solved by the present disclosure is to provide a measurement device, a measurement method, and a computer program product, which can avoid contact between an antenna and a target to satisfactorily measure the communication performance of a communication system.

SUMMARY

A measurement device according to the present disclosure includes a memory and a processor coupled to the memory. The processor is configured to: transmit a distance-detecting radiowave from an antenna; detect a distance between the antenna and a target based on a first reception radiowave received by the antenna, the first reception radiowave being a reflected wave of the distance-detecting radiowave reflected by the target on which a communication system configured to transmit a measurement target radiowave is mounted; perform drive control on at least one of the antenna and the target so that the detected distance reaches a set distance larger than 0; and derive, when the detected distance reaches the set distance, communication performance of the communication system based on a second reception radiowave, the second reception radiowave being the measurement target radiowave received by the antenna.

DETAILED DESCRIPTION

Hereinafter, embodiments of a measurement device, a measurement method, and a computer program product according to the present disclosure will be described with reference to the accompanying drawings.

FIG.1is a schematic diagram illustrating an example of a measurement system1according to the present embodiment. The measurement system1includes a measurement device10and a measurement mechanism20.

The measurement system1is a system for measuring communication performance of a communication system30mounted on a target.

The target is an object on which the communication system30is mounted. The target may be any object as long as the communication system30can be mounted thereon. Examples of the target include a vehicle T, a flying object such as an airplane, a ship, a structure such as a building, a mobile terminal, an electronic device such as a personal computer, or the like. In the present embodiment, a mode in which the target is a vehicle T will be described as an example.

The communication system30is a radiowave transmitter that wirelessly transmits a measurement target radiowave52A. In other words, the communication system30is a radiowave transmitter that transmits the measurement target radiowave52A into the air. Examples of the communication system30include a cordless telephone device, a wireless communication device such as a wireless fidelity (Wi-Fi) router, a radar transmitter, or the like. Examples of the communication system30also include various transmitters used for tracking, detection, communication, or the like.

The measurement target radiowave52A is a radiowave wirelessly transmitted from the communication system30. The measurement target radiowave52A is a radiowave to be measured in the measurement system1of the present embodiment. The measurement target radiowave52A may be any of a millimeter wave, a microwave, an ultra-shortwave, a short wave, a medium wave, and a long wave. The millimeter wave is a radiowave in the millimeter wave frequency band of a frequency band greater than or equal to 26 GHz. The millimeter wave is used for a mobile communication system such as 5G (5th generation mobile communication system), autonomous driving technology of the vehicle T, advanced driver assistance system (ADAS) technology, and the like. The radiowaves used in the ADAS technology include, for example, radar.

For the measurement target radiowave52A transmitted from the communication system30, various wireless communication schemes such as long-distance wireless communication of several hundred meters to several kilometers used in mobile communication systems and the like and short-distance wireless communication up to about 100 m are used. For example, for long-distance wireless communication, a measurement target radiowave52A having a specific frequency and a specific strong intensity is used. Furthermore, for example, for short-distance wireless communication, a measurement target radiowave52A having a specific frequency and a specific weak intensity is used. A strong intensity means an intensity equal to or greater than a predetermined threshold value. A weak intensity means an intensity less than a predetermined threshold value.

In the present embodiment, a mode in which the communication system30is mounted in the vehicle T, as an example of a target, will be described as an example.

The measurement mechanism20is a mechanism for receiving, by an antenna21, the measurement target radiowave52A transmitted from the communication system30mounted on the vehicle T. The measurement mechanism20is capable of receiving the measurement target radiowave52A at every position in all directions of the vehicle T with at least a part thereof being movable.

Specifically, the measurement mechanism20includes an antenna21, a support22, a support23, and a support24.

The antenna21is a device that wirelessly receives a radiowave and wirelessly transmits a radiowave. In other words, the antenna21emits a radiowave into the air and receives a radiowave propagated by the air.

The antenna21is supported by the support24. The support24is a rod-shaped member. The support24supports the antenna21at one end in the longitudinal direction, and the other end thereof is supported by the support23. In the present embodiment, a mode in which the support24is disposed so that the longitudinal direction of the support24substantially coincides with a direction intersecting the vertical direction will be described as an example.

The support23is a rod-shaped member. In the present embodiment, a mode in which the support23is disposed so that the longitudinal direction of the support23substantially coincides with the vertical direction will be described as an example. One end of the support23in the longitudinal direction is supported by the support22. The support22is a rod-shaped member disposed on the ground or the like. In the present embodiment, a mode in which the longitudinal direction of the support22substantially coincides with the horizontal direction will be described as an example.

A support25is a member that supports the vehicle T. In the present embodiment, the support25is a disk-shaped member. In the present embodiment, an example will be described in which the disk face of the support25is disposed in a direction along the horizontal direction. A drive unit25A is provided at the center of the circle of the support25. The drive unit25A is driven under the control by the measurement device10described later. With the drive unit25A driven, the support25rotates about the center of the circle by every predetermined angle (in the direction of arrow Q). As the support25rotates, the vehicle T placed on the support25rotates (in the direction of arrow Q).

The support23is provided with a drive unit23A. The support24is provided with a drive unit24A. The drive unit23A and the drive unit24A are driven under the control by the measurement device10described later. With the drive unit23A driven, the support23moves along the longitudinal direction (direction of arrow X) of the support22. With the drive unit24A driven, the support24moves along the longitudinal direction (direction of arrow Z) of the support23.

The antenna21supported by the support24is movably supported, with respect to the vehicle T, in a direction approaching or separating in the vertical direction and in a direction approaching or separating from a direction intersecting the vertical direction by driving of the drive unit23A and the drive unit24A.

That is, the antenna21is supported so as to be movable between the apex of a hemisphere C with the vehicle T as the center of the sphere and the peripheral edge of the hemisphere C by driving of the drive unit23A and the drive unit24A. Moreover, the antenna21is supported so that the diameter of the hemisphere C can be modified.

Next, the measurement device10will be described. The measurement device10is a device that measures the communication performance of the communication system30on the basis of the measurement target radiowave52A received by the antenna21.

FIG.2is a functional block diagram illustrating an example of the measurement device10. InFIG.2, electrical components included in the measurement system1other than the measurement device10are also illustrated.

The measurement device10includes a processor12, a communication unit14, a storage unit15, an output unit16, and an input unit17. The processor12, the communication unit14, the storage unit15, the output unit16, and the input unit17are communicably connected via a bus19, for example.

The communication unit14is communicably connected with the drive unit23A, the drive unit24A, the drive unit25A, and the antenna21. In the present embodiment, a mode in which the communication unit14is communicably connected with each of the drive unit23A, the drive unit24A, the drive unit25A, and the antenna21by wire will be described as an example. Furthermore, in the present embodiment, a mode in which the communication unit14is communicably connected to the communication system30by wire will be described as an example.

The storage unit15stores various types of information. The output unit16outputs various types of information. The output unit16is, for example, a display that displays an image, a speaker that outputs sound, or the like. Note that the output unit16may have a communication function of communicating with an external information processing device via a network or the like. With the communication function provided, the output unit16can transmit various types of information to an external information processing device. The input unit17receives operation input by a user. The input unit17is, for example, a keyboard, a pointing device, a touch panel, or the like.

The processor12executes various types of information processing. In the present embodiment, the processor12includes a drive control module12A, a transmission control module12B, a detection module12C, and a derivation module12D. Some or all of the drive control module12A, the transmission control module12B, the detection module12C, and the derivation module12D may be implemented by causing a processing device such as a central processing unit (CPU) to execute a program, that is, implementation by software, may be implemented by hardware such as an integrated circuit (IC), or may be implemented by using software and hardware in combination. Furthermore, at least one of the drive control module12A, the transmission control module12B, the detection module12C, and the derivation module12D may be mounted on an external information processing device communicably connected with the measurement device10via a network or the like.

The drive control module12A performs drive control on at least one of the antenna21and the vehicle T. The drive control means to control to move the position of at least one of the antenna21and the vehicle T in the real space. In the present embodiment, a mode of performing drive control to move the position of the antenna21will be described as an example.

Specifically, the drive control module12A performs drive control on the drive unit23A, the drive unit24A, and the drive unit25A. For example, the drive control module12A drives the drive unit23A, the drive unit24A, and the drive unit25A so that the antenna21is sequentially disposed in each of regions obtained by dividing the outer periphery of the hemisphere C (seeFIG.1) centered on the vehicle T into a plurality of regions.

Specifically, the drive control module12A performs drive control on the antenna21in a direction approaching the vehicle T or a direction away from the vehicle T by the drive control of the drive unit23A and the drive unit24A. Then, the drive control module12A controls the drive unit25A every time the position of the antenna21is controlled to move to a next measurement position between the apex of the hemisphere C and the peripheral edge of the hemisphere C. Under the control by the drive unit25A, the drive control module12A rotationally drives the vehicle T placed on the support25at every predetermined rotation angle.

In the measurement device10, every time the antenna21is moved to a next measurement position by the drive control by the drive control module12A and the vehicle T placed on the support25is rotationally driven at a predetermined rotation angle, the communication performance of the communication system30is derived using a second reception radiowave52B of the measurement target radiowave52A received by the antenna21. That is, the measurement device10is configured to be capable of acquiring the second reception radiowave52B received in each of the regions obtained by dividing the outer periphery into a plurality of regions along the outer periphery of the hemisphere C centered on the vehicle T. In other words, the measurement device10is configured to be capable of acquiring the second reception radiowave52B received at every position in all directions of the vehicle T.

The transmission control module12B controls the start and stop of transmission of the measurement target radiowave52A from the communication system30.

The transmission control module12B transmits a transmission start signal indicating the start of transmission of the measurement target radiowave52A to the communication system30via the communication unit14. The communication system30that has received the transmission start signal of the measurement target radiowave52A starts to wirelessly transmit the measurement target radiowave52A. The transmission control module12B further transmits a transmission stop signal indicating the stop of transmission of the measurement target radiowave52A to the communication system30via the communication unit14. The communication system30that has received the transmission stop signal of the measurement target radiowave52A stops transmission of the measurement target radiowave52A.

Furthermore, the transmission control module12B causes the antenna21to transmit a distance-detecting radiowave50A.

The distance-detecting radiowave50A is a radiowave used for detection of the distance between the antenna21and the vehicle T. In the present embodiment, a mode in which the distance-detecting radiowave50A is a modulated wave will be described as an example. For example, the transmission control module12B outputs a transmission signal of the distance-detecting radiowave50A representing a pulse wave of a predetermined specific frequency to the antenna21via the communication unit14. When receiving the transmission signal from the transmission control module12B via the communication unit14, the antenna21starts transmitting the distance-detecting radiowave50A represented by the transmission signal.

The detection module12C detects the distance between the antenna21and the vehicle T on the basis of a first reception radiowave50B received by the antenna21.

The first reception radiowave50B is a reception radiowave obtained by the antenna21receiving a reflected wave of the distance-detecting radiowave50A transmitted from the antenna21and reflected by the vehicle T.

The detection module12C calculates the distance between the antenna21and the vehicle T on the basis of the distance-detecting radiowave50A and the first reception radiowave50B.

For example, the detection module12C derives a time from transmission of the distance-detecting radiowave50A to reception of the first reception radiowave50B that is a reflected wave of the distance-detecting radiowave50A by the vehicle T by using a known time domain scheme or the like. Then the detection module12C calculates the distance between the vehicle T and the antenna21using the derived time and the speed of the radiowave.

Note that the transmission control module12B may cause the antenna21to transmit a modulated wave by a frequency modulated continuous wave (FMCW) scheme as the distance-detecting radiowave50A. In this case, the detection module12C generates an intermediate frequency (IF) signal from the distance-detecting radiowave50A and the first reception radiowave50B and performs known signal processing on the IF signal and thereby calculates the distance. For example, the detection module12C derives a frequency spectrum by performing analog/digital (AD) conversion and further performing Fourier transform (FFT) on the IF signal. Then the detection module12C calculates the distance between the vehicle T and the antenna21from the derived frequency spectrum.

Alternatively, the detection module12C may calculate the distance between the antenna21and the vehicle T on the basis of the difference between the intensity of the distance-detecting radiowave50A and the intensity of the first reception radiowave50B. For example, the detection module12C stores the distance corresponding to the difference between the amplitude intensity of the distance-detecting radiowave50A and the amplitude intensity of the first reception radiowave50B in the storage unit15in advance in association with each other. Furthermore, the detection module12C may derive the distance between the antenna21and the vehicle T by reading, from the storage unit15, a distance corresponding to a difference between the amplitude intensity of the distance-detecting radiowave50A and the amplitude intensity of the first reception radiowave50B.

The drive control module12A performs drive control on at least one of the antenna21and the vehicle T so that the distance detected by the detection module12C reaches a set distance larger than 0. In the present embodiment, as described above, a mode in which the drive control module12A performs drive control on the drive unit23A and the drive unit24A and thereby performs drive control on the position of the antenna21will be described as an example.

The set distance is a target distance between the vehicle T and the antenna21at the time of measurement. As described above, various wireless communication schemes such as long-distance wireless communication and short-distance wireless communication are used for the measurement target radiowave52A transmitted from the communication system30. For example, for long-distance wireless communication, a measurement target radiowave52A having a specific frequency and a specific intensity is used. For short-distance wireless communication, a measurement target radiowave52A having a specific frequency and a specific weak intensity is used.

At the time of measuring the communication performance of the measurement target radiowave52A for short-distance wireless communication, it is necessary to dispose the antenna21at a position closer to the vehicle T. On the other hand, when the communication performance of the measurement target radiowave52A for long-distance wireless communication is measured, the antenna21needs to be disposed at a position far from vehicle T. Therefore, as a set distance, a target distance for measuring the communication performance corresponding to the wireless communication scheme is determined. Note that, as the set distance, a value larger than 0 is set in advance from the perspective of avoiding a collision between the antenna21and the vehicle T.

In the present embodiment, the drive control module12A performs drive control on at least one of the antenna21and the vehicle T so that the detected distance reaches a set distance corresponding to the wireless communication scheme of the measurement target radiowave52A transmitted from the communication system30. First, the drive control module12A acquires a set distance corresponding to the wireless system of the measurement target radiowave52A.

For example, the drive control module12A acquires the wireless communication scheme of the measurement target radiowave52A from the communication system30via the communication unit14. Alternatively, for example, the drive control module12A may acquire the wireless communication scheme input by a user from the input unit17.

The drive control module12A further reads a set distance corresponding to the acquired wireless communication scheme from the storage unit15to acquire a set distance corresponding to the wireless communication scheme of the measurement target radiowave52A.

For example, a set distance correspondence table15A may be stored in advance in the storage unit15. The set distance correspondence table15A is a table in which the wireless communication scheme and the set distance are associated with each other. Note that the data format of the set distance correspondence table15A may be a database or the like and is not limited to tables. Specifically, the set distance correspondence table15A is a table in which wireless communication schemes and set distances representing target distances for measuring the communication performance depending on the wireless communication schemes are associated in advance. Specifically, in the set distance correspondence table15A, for example, a set distance indicating N mm is registered in advance in association with long-distance wireless communication that is a wireless communication scheme. N is an integer greater than 0. In addition, in the set distance correspondence table15A, for example, a set distance indicating L mm is registered in advance in association with short-distance wireless communication that is a wireless communication scheme. L is an integer greater than 0 and less than N.

The drive control module12A is only required to acquire the set distance corresponding to the wireless communication scheme of the measurement target radiowave52A by reading a set distance corresponding to the acquired wireless communication scheme from the storage unit15.

Note that the wireless communication schemes and the set distances registered in the set distance correspondence table15A may be modifiable in accordance with, for example, an operation instruction to the input unit17by a user.

Alternatively, the user may input a desired set distance by operating the input unit17. In this case, the drive control module12A is only required to acquire the set distance from the input unit17. By acquiring the set distance from the input unit17, the drive control module12A can acquire any set distance desired by the user. However, as described above, it is essential that the set distance be a value exceeding 0.

The drive control module12A performs drive control on at least one of the antenna21and the vehicle T so that the distance between the antenna21and the vehicle T detected by the detection module12C reaches the acquired set distance.

In the present embodiment, the drive control module12A performs drive control on the antenna21in a direction approaching the vehicle T or a direction away from the vehicle T by the drive control of the drive unit23A and the drive unit24A. For example, the drive control module12A moves the antenna21to a predetermined position in the real space by drive control of the drive unit23A and the drive unit24A.

Then the drive control module12A acquires, from the detection module12C, the distance between the antenna21and the vehicle T detected from the distance-detecting radiowave50A transmitted from the antenna21at that position and the first reception radiowave50B that is a reflected wave of the distance-detecting radiowave50A reflected by the vehicle T and received by the antenna21at that position.

In a case where the distance detected by the detection module12C is less than the set distance, the drive control module12A stops the drive control of the antenna21and the vehicle T. In the present embodiment, in a case where the distance detected by the detection module12C is less than the set distance, the drive control module12A stops the drive control of the drive unit23A and the drive unit24A, thereby performing stop control to stop the movement of the antenna21.

In a case where the distance detected by the detection module12C is less than the set distance, the drive control module12A stops the drive control of the antenna21and the vehicle T, and thus contact and collision between the antenna21and the vehicle T are avoided.

Moreover, in a case where the distance detected by the detection module12C is less than the set distance, the drive control module12A performs drive control on at least one of the antenna21and the vehicle T so that the distance between the antenna21and the vehicle T increases. In the present embodiment, the drive control module12A moves the antenna21in a direction away from the vehicle T by controlling the drive unit23A and the drive unit24A.

In a case where the distance detected by the detection module12C is less than the set distance, the drive control module12A is only required to perform at least one of stop control of the driving of the antenna21and the vehicle T and drive control of increasing the distance between the antenna21and the vehicle T. In the present embodiment, in a case where the distance detected by the detection module12C is less than the set distance, the drive control module12A performs drive control to move the antenna21in a direction away from the vehicle T after stopping the drive control of the antenna21.

In a case where the distance detected by the detection module12C exceeds the set distance, the drive control module12A drives at least one of the antenna21and the vehicle T so that the distance between the antenna21and the vehicle T decreases. In the present embodiment, in a case where the distance detected by the detection module12C exceeds the set distance, the drive control module12A performs drive control to move the antenna21in a direction approaching the vehicle T by performing drive control on the drive unit23A and the drive unit24A.

In a case where the distance detected by the detection module12C reaches the set distance, the derivation module12D derives the communication performance of the communication system30on the basis of the second reception radiowave52B that is the measurement target radiowave52A received by the antenna21.

For example, the derivation module12D derives, as the communication performance, information in which information representing the second reception radiowave52B that has been acquired is associated with position information of the antenna21in the real space at the time of acquisition of second reception radiowave52B. As the position of the antenna21in the real space, a position on the outer surface of the hemisphere C of the antenna21derived by the control of the drive unit23A, the drive unit24A, and the drive unit25A by the drive control module12A may be used.

Note that the derivation module12D is only required to use at least one of the amplitude, the wavelength, the period, and the speed of the second reception radiowave52B that have been acquired as the information representing the second reception radiowave52B.

Next, an example of a flow of information processing executed by the measurement device10of the present embodiment will be described.

FIG.3is a flowchart illustrating an example of a flow of information processing executed by the measurement device10. In a state immediately before the flowchart illustrated inFIG.3is executed, description will be given on the premise that the antenna21and the communication system30are in a state of not transmitting radiowaves. The description is also based on the premise that, before execution of the flowchart illustrated inFIG.3, the processor12has acquired the set distance corresponding to the wireless communication scheme of the measurement target radiowave52A in advance.

The drive control module12A controls the movement of the antenna21to a next measurement position (step S100). The drive control module12A drives and controls the drive unit23A and the drive unit24A to move the position of the antenna21on the outer periphery of the hemisphere C (seeFIG.1) centered on the vehicle T to the next measurement position between the apex of the hemisphere C on the outer periphery and the peripheral edge of the hemisphere C.

The transmission control module12B transmits the transmission signal of the distance-detecting radiowave50A to the antenna21via the communication unit14(step S102). The antenna21that has received the transmission signal of the distance-detecting radiowave50A starts transmitting the distance-detecting radiowave50A.

The detection module12C acquires the first reception radiowave50B that is a reflected wave of the distance-detecting radiowave50A reflected by the vehicle T and received by the antenna21(step S104). The detection module12C acquires the first reception radiowave50B from the antenna21via the communication unit14.

The detection module12C detects the distance between the antenna21and the vehicle T on the basis of the distance-detecting radiowave50A and the first reception radiowave50B acquired in step S104(step S106).

The drive control module12A determines whether or not the distance detected in step S106is less than the set distance (step S108). If it is determined that the distance detected in step S106is less than the set distance (step S108: Yes), the process proceeds to step S110.

In step S110, the drive control module12A stops the drive control of the drive unit23A and the drive unit24A and thereby performs stop control of stopping the movement of the antenna21(step S110). The processing in step S110avoids contact or collision between the antenna21and the vehicle T.

Then the drive control module12A performs drive control on the antenna21so that the distance between the antenna21and the vehicle T increases (step S112). In step S112, the drive control module12A controls the drive unit23A and the drive unit24A, thereby moving the antenna21in a direction away from the vehicle T. Then, the process returns to step S104described above.

On the other hand, if it is determined that the distance detected in step S106is equal to or greater than the set distance in step S108(step S108: No), the drive control module12A proceeds to step S114. In step S114, the drive control module12A determines whether or not the distance detected in step S106reaches the set distance (step S114).

If a negative determination is made in step S114(step S114: No), the process proceeds to step S116. That is, if the distance detected in step S106is larger than the set distance, the drive control module12A makes a negative determination in step S114(step S114: No).

In step S116, the drive control module12A performs drive control on the antenna21so that the distance between the antenna21and the vehicle T decreases (step S116). The drive control module12A performs drive control to move the antenna21in a direction approaching the vehicle T by performing drive control on the drive unit23A and the drive unit24A. Then, the process returns to step S104described above.

On the other hand, if an affirmative determination is made in step S114(step S114: Yes), the process proceeds to step S118. If the distance detected in step S106reaches the set distance, the drive control module12A makes an affirmative determination in step S114(step S114: Yes).

In step S118, the drive control module12A stops the drive control of the drive unit23A and the drive unit24A and thereby performs stop control of stopping the movement of the antenna21(step S118). By the processing of step S118, a state in which the distance between the antenna21and the vehicle T reaches the set distance is maintained.

Next, the transmission control module12B stops transmission of the transmission signal of the distance-detecting radiowave50A to the antenna21(step S120). The antenna21, to which the transmission of the transmission signal of the distance-detecting radiowave50A has been stopped, stops transmission of the distance-detecting radiowave50A.

Next, the transmission control module12B transmits the transmission start signal indicating the start of transmission of the measurement target radiowave52A to the communication system30(step S122). The communication system30that has received the transmission start signal starts transmission of the measurement target radiowave52A.

The derivation module12D acquires the second reception radiowave52B that is the measurement target radiowave52A received by the antenna21(step S124). The derivation module12D acquires the second reception radiowave52B from the antenna21via the communication unit14.

The derivation module12D derives the communication performance of the communication system30on the basis of the second reception radiowave52B acquired in step S214(step S126). Then the derivation module12D stores the communication performance derived in step S126in the storage unit15(step S128).

Next, the drive control module12A controls the drive unit25A and thereby rotationally drives the vehicle T placed on the support25at a predetermined rotation angle (step S130). Then, the process proceeds to step S132. The predetermined rotation angle may be determined in advance. The predetermined rotation angle may be, for example, 5°, 10°, or 30°, but it is not limited thereto. The predetermined rotation angle may be set and modifiable by an operation instruction or the like to the input unit17by a user.

In step S132, the transmission control module12B transmits, to the communication system30, the transmission stop signal indicating the stop of transmission of the measurement target radiowave52A (step S132). The communication system30that has received the transmission stop signal stops transmission of the measurement target radiowave52A. Note that the processing of step S130may be executed after the processing of step S132.

Next, the processor12determines whether or not the vehicle T placed on the support25has been rotationally driven by 360° in the circumferential direction (see the direction of arrow Q inFIG.1) in a state where the antenna21is positioned at the measurement position between the apex and the peripheral edge in the hemisphere C that has been adjusted in step S100(step S134).

If a negative determination is made in step S134(step S134: No), the process returns to step S102described above.

If an affirmative determination is made in step S134(step S134: Yes), the process proceeds to step S136.

In step S136, the processor12determines whether or not to end the measurement processing (step S136). For example, the processor12makes the determination in step S136by determining whether or not measurement of the communication performance of the communication system30at measurement positions in all directions centered on the vehicle T has been completed. If a negative determination is made in step S136(step S136: No), the process returns to step S100described above. If an affirmative determination is made in step S136(step S136: Yes), the present routine is ended.

As described above, the measurement device10of the present embodiment includes the transmission control module12B, the detection module12C, and the drive control module12A. The transmission control module12B causes the antenna21to transmit the distance-detecting radiowave50A. The detection module12C detects the distance between the antenna21and the vehicle T on the basis of the first reception radiowave50B received by the antenna21. The first reception radiowave50B is a reception radiowave obtained by the antenna21receiving a reflected wave of the distance-detecting radiowave50A reflected by the vehicle T on which the communication system30that transmits the measurement target radiowave52A is mounted. The drive control module12A performs drive control on at least one of the antenna21and the vehicle T so that the detected distance reaches the set distance larger than 0. In a case where the detected distance reaches the set distance, the derivation module12D derives the communication performance of the communication system30on the basis of the second reception radiowave52B that is the measurement target radiowave52A received by the antenna21.

As described above, in the measurement device10of the present embodiment, the drive control module12A performs drive control on at least one of the antenna21and the vehicle T so that the distance between the antenna21and the vehicle T detected by the detection module12C reaches the set distance larger than 0. Furthermore, in a case where the distance between the antenna21and the vehicle T reaches the set distance, the derivation module12D derives the communication performance of the communication system30on the basis of the second reception radiowave52B received by the antenna21positioned at the set distance.

Therefore, in the measurement device10of the present embodiment, it is possible to avoid contact or collision between the antenna21and the vehicle T to satisfactorily measure the communication performance of the communication system30.

Therefore, the measurement device10of the present embodiment can avoid contact between the antenna21and the target (vehicle T) to satisfactorily measure the communication performance of the communication system30.

Moreover, the drive control module12A of the measurement device10of the present embodiment performs drive control on at least one of the antenna21and the vehicle T so that the detected distance reaches the set distance corresponding to the wireless communication scheme of the measurement target radiowave52A.

FIGS.4and5are explanatory diagrams of examples of a set distance.FIG.4is a diagram illustrating an example of a hemisphere CA representing a group of measurement positions in a case where the set distance is Rl. The hemisphere CA is an example of the hemisphere C.FIG.5is a diagram illustrating an example of a hemisphere CB representing a group of measurement positions in a case where the set distance is R2. The measurement distance R2is shorter than the measurement distance R1. The hemisphere CB is an example of the hemisphere C.

As illustrated inFIGS.4and5, in the measurement device10of the present embodiment, the set distance between the antenna21and the vehicle T can be made variable. Therefore, the measurement device10of the present embodiment can adjust the distance between the antenna21and the vehicle T to a set distance corresponding to a wireless communication scheme.

Furthermore, the measurement device10of the present embodiment derives the communication performance of the communication system30on the basis of the second reception radiowave52B received by the antenna21in a state where a contact or collision with the vehicle T is suppressed and the distance to the vehicle T has been adjusted to the set distance. Therefore, in addition to the above effects, the measurement device10of the present embodiment can measure the communication performance of the communication system30with high accuracy while avoiding contact between the antenna21and the vehicle T.

Note that, inFIGS.4and5, as a diagram schematically illustrating the shape of the hemisphere C, the hemisphere C in which a cross section parallel to the peripheral edge of the hemisphere C is a substantially perfect circle is illustrated as an example. However, since the hemisphere C representing a group of measurement positions by the antenna21is actually a group of measurement positions separated from the outer surface of the vehicle T by a set distance, it goes without saying that the shape extends along the outer shape of the vehicle T.

Moreover, the measurement device10of the present embodiment detects the distance between the antenna21and the vehicle T on the basis of the first reception radiowave50B that is a reflected wave, by the vehicle T, of the distance-detecting radiowave50A and received by the antenna21. Furthermore, the measurement device10derives the communication performance of the communication system30on the basis of the second reception radiowave52B of the measurement target radiowave52A received by the antenna21.

As described above, the measurement device10of the present embodiment detects the distance and derives the communication performance using the antenna21. Therefore, the measurement device10of the present embodiment can avoid contact between the antenna21and the vehicle T and measure the communication performance of the communication system30with high accuracy with a simple configuration without being separately provided with a device for distance detection.

Note that, in the present embodiment, a mode in which the measurement device10performs drive control to move the position of the antenna21with respect to the vehicle T by driving and controlling the drive unit23A and the drive unit24A has been described as an example. However, the measurement device10is only required to perform drive control to move the position in the real space of at least one of the vehicle T and the antenna21and is not limited to the mode of performing drive control on the antenna21. For example, the drive unit25A provided to the support25is caused to function as a drive unit that rotationally drives the support25and moves the position of the support25in the real space. In this case, the measurement device10can control the position of the support25in the real space and drive and control the position of the vehicle T placed on the support25by performing drive control on the drive unit25A. That is, the measurement device10may move the position of at least one of the antenna21and the vehicle T in the real space by performing drive control on the drive unit23A, the drive unit24A, and the drive unit25A.

Furthermore, in the present embodiment, the case where the target on which the communication system30is mounted is the vehicle T has been described as an example. However, the target is not limited to the vehicle T. As described above, the target may be any object on which the communication system30is mounted and may be a flying object such as an airplane, a ship, a structure such as a building, a mobile terminal, or an electronic device such as a personal computer. The measurement device10of the present embodiment is particularly usefully applied to derive the communication performance of the communication system30mounted on an object having a non-uniform outer shape, a precision object weak against impact, or the like.

Next, an example of a hardware configuration of the measurement device10of the above embodiment will be described.

FIG.6is a hardware configuration diagram illustrating an example of the measurement device10according to the above embodiment.

The measurement device10of the above embodiment includes a control device such as a CPU60A, a storage device such as a read only memory (ROM)60B, a random access memory (RAM)60C, and a hard disk drive (HDD), an I/F unit60D that is an interface with various devices, and a bus60E that connects the units and have a hardware configuration using a normal computer.

In the measurement device10of the above embodiment, the CPU60A reads a program from the ROM60B onto the RAM60C and executes the program, whereby the above units are implemented on the computer.

Note that the program for executing each piece of the above processing executed in the measurement device10of the above embodiment may be stored in the HDD. Alternatively, the program for executing each piece of the above processing executed in the measurement device10of the above embodiment may be provided by being incorporated in the ROM60B in advance.

Further alternatively, the program for executing each piece of the above processing executed in the measurement device10of the above embodiment may be stored as a file in an installable format or an executable format in a computer-readable storage medium such as a CD-ROM, a CD-R, a memory card, a digital versatile disk (DVD), or a flexible disk (FD) and provided as a computer program product. Moreover, the program for executing each piece of the above processing executed in the measurement device10of the above embodiment may be stored in a computer connected to a network such as the Internet and provided by being downloaded via the network. Furthermore, the program for executing each piece of the above processing executed in the measurement device10of the above embodiment may be provided or distributed via a network such as the Internet.

According to a measurement device, a measurement method, and a computer program product according to the present disclosure, it is possible to avoid contact between an antenna and a target to satisfactorily measure the communication performance of a communication system.