System and method for measuring object reflection characteristics

Abstract

To mitigate influences due to position errors with respect to a measurement object and measure the reflection characteristic of the measurement object with good accuracy by a simple structure.SOLUTION: A prescribed transmission direction in which the maximum transmission strength of a transmit antenna 10 is reached, is oriented by being shifted by a first prescribed angle (e.g., an angle φs), as referenced to the phase center of the transmit antenna 10, in a direction to separate from a receive antenna 20, with respect to a virtual line C linking the phase center of the transmit antenna 10 and an ideal measurement point P which is apart by a prescribed distance d0. A prescribed transmission direction in which the maximum transmission strength of the receive antenna 20 is reached, is oriented by being shifted by a second prescribed angle (e.g., an angle φs), as referenced to the phase center of the receive antenna 20, in a direction to separate from the transmit antenna 10, with respect to a virtual line D linking the phase center of the receive antenna 20 and the ideal measurement point P which is apart by the prescribed distance d0.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an object reflection characteristic measuring system and an object reflection characteristic measuring method for measuring radio wave reflection characteristics of an object to be measured. [Background technology]

[0002] In conventional measurement technology, a method is known in which a transmitting antenna and a receiving antenna are placed at a predetermined distance and angle from the object to be measured, radio waves are irradiated from the transmitting antenna to the object to be measured, and the radio waves reflected from the object to be measured are received by the receiving antenna, thereby measuring the reflection characteristics of the object to be measured.

[0003] For example, Patent Document 1 describes a radio wave propagation measurement system in which a transmitting antenna transmits a transmission wave, which is a radio signal in a specific frequency band, to a target location, a receiving antenna receives the reflected wave, the transmitted wave and the reflected wave are compared to calculate the reflection intensity as a result of the comparison, and the reflection characteristics of the radio waves at the target location are calculated based on the target location and the reflection intensity.

[0004] Furthermore, in conventional measurement technology, a method is known in which the antenna of a wireless terminal is rotated to measure the antenna directivity characteristics of the wireless terminal.

[0005] For example, Patent Document 2 describes an antenna directional characteristic measurement system that rotates a wireless terminal by a predetermined rotation angle, measures the field strength or power of radio waves received by a measurement antenna fixed at a predetermined position in response to radio waves output by a terminal antenna within the wireless terminal, obtains a tentative directional characteristic of the terminal antenna, outputs a reception angle error for each rotation angle of the wireless terminal, a propagation loss error in free space for each rotation angle of the wireless terminal, and a gain error of the measurement antenna for each rotation angle of the wireless terminal based on the position of the terminal antenna when the wireless terminal is in a reference position, corrects the tentative directional characteristic of the terminal antenna using the above reception angle error, propagation loss error, and gain error, and determines the directional characteristic as if the terminal antenna were rotated at the position of the reference point. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2015 / 029179 [Patent Document 2] Patent No. 6535046 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the method described in Patent Document 1 has the problem that unless the positions and angles of the transmitting antenna and receiving antenna relative to the object to be measured are accurately positioned to match the ideal measurement state, the reflection characteristics of the object to be measured cannot be measured with high accuracy, resulting in large errors in the reflection characteristics of the object to be measured. Because it takes time and effort to set the positions and angles of the transmitting antenna and receiving antenna relative to the object to match the ideal measurement state, it is practically difficult to accurately measure the reflection characteristics of the object to be measured when the measurement area is wide.

[0008] Furthermore, the method described in Patent Document 2 uses a terminal holding and rotating mechanism that rotates the terminal antenna within the wireless terminal that transmits radio waves, but this is intended to accurately measure the directional characteristics of the terminal antenna, and is not intended to determine the reflection characteristics of the object to be measured by using reflected waves from the object to be measured.

[0009] In order to solve the above problems, the present invention aims to provide an object reflection characteristic measurement system and an object reflection characteristic measurement method that can reduce the influence of positional errors relative to the object to be measured and accurately measure the reflection characteristics of the object to be measured using a simple configuration. [Means for solving the problem]

[0010] In order to achieve the above object, an object reflection characteristic measurement system according to the present invention is an object reflection characteristic measurement system for measuring reflection characteristics of a measurement object, comprising: a transmitting antenna having directivity with maximum transmission strength in a predetermined transmission direction, which irradiates a transmission wave onto an object to be measured; a receiving antenna having directivity with maximum reception strength in a predetermined reception direction, and receiving a reflected wave from the object to be measured; a support that fixes and supports the transmitting antenna and the receiving antenna so that the relative positions of the transmitting antenna and the receiving antenna are fixed; a received power measurement unit that measures the received power of the reflected wave received by the receiving antenna; a reflection characteristic calculation unit that calculates the reflection characteristic of the object to be measured based on the received power of the reflected wave, the predetermined transmission direction of the transmitting antenna is oriented at a first predetermined angle from the phase center of the transmitting antenna as a reference, in a direction away from the receiving antenna, with respect to a line connecting the phase center of the transmitting antenna and an ideal measurement point a predetermined distance away from the phase center of the transmitting antenna; The predetermined receiving direction of the receiving antenna is characterized in that it is oriented at a second predetermined angle away from the transmitting antenna, with respect to a line connecting the phase center of the receiving antenna and the ideal measurement point a predetermined distance away, based on the phase center of the receiving antenna.

[0011] The above configuration reduces the influence of positional errors relative to the object to be measured, enabling accurate measurement of the reflection characteristics of the object with a simple configuration. In particular, by orienting the transmitting antenna and receiving antenna such that the predetermined transmitting direction resulting in maximum transmitting strength and the predetermined receiving direction resulting in maximum receiving strength are offset by a first predetermined angle and a second predetermined angle, respectively, from the direction toward the ideal measurement point, the allowable error range of the distance to the object to be measured can be increased, thereby reducing the influence of errors in the distance to the object to be measured. While the first predetermined angle and the second predetermined angle are preferably the same, they may also be different angles.

[0012] In the above-described configuration, the object reflection characteristic measuring system according to the present invention may further include a distance measuring unit that is arranged to be fixed to the support body and that measures the distance to the measurement object.

[0013] According to the above configuration, the distance from the transmitting antenna and receiving antenna fixedly supported on the support to the object to be measured can be measured, and the distance from the transmitting antenna and receiving antenna to the object to be measured can be set to a distance that allows the reflection characteristics of the object to be measured appropriately.

[0014] In the above-described configuration, the object reflection characteristic measuring system according to the present invention may also have a rotation mechanism that rotates the support body to which the transmitting antenna and the receiving antenna are fixedly supported, around a rotation axis that is perpendicular to a horizontal plane that includes the phase center of the transmitting antenna and the phase center of the receiving antenna.

[0015] According to the above configuration, the transmitting antenna and the receiving antenna fixedly supported on the support can be rotated together with the rotation axis as the center of rotation, and the reflected wave can be received by the receiving antenna at a plurality of different rotation angles to obtain the received power of the reflected wave.

[0016] In the object reflection characteristic measuring system according to the present invention, in the above configuration, the rotation axis may be located on the perpendicular bisector of a line segment connecting the phase center of the transmitting antenna and the phase center of the receiving antenna.

[0017] According to the above configuration, by rotating the support body to which the transmitting antenna and the receiving antenna are fixedly supported around the rotation axis as the center of rotation, the angle between the predetermined transmitting direction in which the transmitting antenna has the maximum transmitting strength and the direction toward the object to be measured and the angle between the predetermined receiving direction in which the receiving antenna has the maximum receiving strength and the direction toward the object to be measured can be changed so that the increase and decrease are opposite.

[0018] In the above-described configuration, the object reflection characteristic measuring system according to the present invention may further include a maximum received power identifying unit that acquires the received power of the reflected wave received by the receiving antenna at a plurality of different rotation angles by rotating the support body, and identifies the maximum received power at which the received power of the reflected wave is maximum.

[0019] According to the above configuration, the maximum received power of the reflected wave can be determined from the received power of the reflected wave acquired at a plurality of different rotation angles. In particular, by acquiring the received power of the reflected wave at a plurality of different rotation angles while rotating the transmitting antenna and the receiving antenna integrally around the rotation axis as the center of rotation, it is possible to allow for angular deviation of the initial positions of the transmitting antenna and the receiving antenna relative to the object to be measured, and to reduce the influence of angular error with respect to the object to be measured.

[0020] In the object reflection characteristic measuring system according to the present invention, in the aforementioned configuration, the reflection characteristic calculation unit may calculate the reflection characteristic of the object to be measured based on the maximum received power.

[0021] According to the above configuration, it is possible to accurately measure the reflection characteristics of the measurement object based on the maximum received power identified from the received power of reflected waves acquired at a plurality of different rotation angles.

[0022] In the above-described configuration, the object reflection characteristic measuring system according to the present invention may further include an angle measuring unit that measures a rotation angle of the support body around the rotation axis as a center of rotation.

[0023] According to the above configuration, the rotation angle of the support is measured while rotating the support, and the relationship between the rotation angle and the received power can be grasped.

[0024] In the above-described configuration, the object reflection characteristic measuring system according to the present invention may further include a received power recording unit that records the received power of the reflected wave received by the receiving antenna in a predetermined storage medium in association with the rotation angle of the support body.

[0025] According to the above configuration, the received power of the reflected wave received by the receiving antenna for each rotation angle of the support is recorded in a specified storage medium, and the maximum received power can be determined from the received power of the reflected wave for each rotation angle in an overview manner.

[0026] In the above configuration, the object reflection characteristic measuring system according to the present invention may further include a movement mechanism that moves the support to which the transmitting antenna and the receiving antenna are fixedly supported.

[0027] According to the above configuration, the transmitting antenna and the receiving antenna can be disposed on a mobile body having a moving mechanism and can be moved, so that the measurement position can be easily and freely changed.

[0028] In the above-described configuration, the object reflection characteristic measuring system according to the present invention may further include a self-positioning unit that identifies the positions of the support body to which the transmitting antenna and the receiving antenna are fixedly supported.

[0029] According to the above configuration, when measuring the reflection characteristics of the measurement object, the positions of the transmitting antenna and the receiving antenna provided in the object reflection characteristics measurement system can be identified.

[0030] In the above-described configuration, the object reflection characteristic measurement system according to the present invention may also include a reflection characteristic recording unit that records the reflection characteristics of the object to be measured in a predetermined storage medium in association with the positions of the support on which the transmitting antenna and the receiving antenna are fixedly supported.

[0031] According to the above configuration, the reflection characteristics of the object to be measured and the measurement location of those reflection characteristics can be recorded in a predetermined storage medium for secondary use. For example, it becomes possible to perform a radio wave propagation simulation for building a wireless network by using information on the position and reflection characteristics of the object to be measured, which are identified from the measurement location.

[0032] In the object reflection characteristic measuring system according to the present invention, in the above configuration, a reflection coefficient of the measurement object may be measured as the reflection characteristic of the measurement object.

[0033] According to the above configuration, the influence of positional errors with respect to the measurement object can be reduced, and the reflection coefficient of the measurement object can be measured with high accuracy using a simple configuration.

[0034] In order to achieve the above object, an object reflection characteristic measurement method according to the present invention is a method for measuring reflection characteristics of a measurement object, comprising: preparing a transmitting antenna having directivity with maximum transmission strength in a predetermined transmission direction and irradiating a transmission wave onto a measurement object; preparing a receiving antenna having directivity with maximum reception strength in a predetermined reception direction and configured to receive a reflected wave from the object to be measured; a step of fixing and supporting the transmitting antenna and the receiving antenna on a support so that the relative positions of the transmitting antenna and the receiving antenna are fixed; measuring the received power of the reflected wave received by the receiving antenna; calculating the reflection characteristics of the object to be measured based on the received power of the reflected wave, When the transmitting antenna is fixedly supported on the support, the predetermined transmission direction of the transmitting antenna is shifted by a first predetermined angle from the phase center of the transmitting antenna as a reference in a direction away from the receiving antenna with respect to a line connecting the phase center of the transmitting antenna and an ideal measurement point separated by a predetermined distance; When the receiving antenna is fixedly supported on the support, the predetermined receiving direction of the receiving antenna is shifted away from the transmitting antenna by a second predetermined angle with respect to a straight line connecting the phase center of the receiving antenna and the ideal measurement point a predetermined distance away from the receiving antenna.

[0035] According to the above procedure, the influence of positional errors relative to the measurement object can be reduced, and the reflection characteristics of the measurement object can be accurately measured with a simple configuration. In particular, for the transmitting antenna and the receiving antenna, by orienting the predetermined transmitting direction with high transmission strength and the predetermined receiving direction with high reception strength by a first predetermined angle and a second predetermined angle, respectively, relative to the direction toward the ideal measurement point, the tolerance for error in the distance to the measurement object can be increased, and the influence of distance errors to the measurement object can be reduced. Note that the first predetermined angle and the second predetermined angle are preferably the same angle, but may be different angles. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a diagram illustrating an example of the configuration of an object reflection characteristic measuring system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating the arrangement of a transmitting antenna and a receiving antenna in an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram for explaining the effect of reducing distance errors achieved in an embodiment of the present invention, showing a case where the distance between the moving body and the object to be measured is closer than the ideal distance. [Figure 4] FIG. 10 is a diagram for explaining the effect of reducing distance errors achieved in an embodiment of the present invention, showing a case where the distance between the moving body and the object to be measured is greater than the ideal distance. [Figure 5] 10A and 10B are diagrams for explaining the effect of reducing angle errors achieved in an embodiment of the present invention. [Figure 6] 6 is a graph showing the relationship between the angle ξ formed by the imaginary line Bz and the imaginary line B shown in FIG. 5 and the received power of the radio wave received by the receiving antenna. [Figure 7] 1 is a flowchart showing a processing flow according to an embodiment of the present invention. [Figure 8] FIG. 1 is a schematic block diagram showing an example of the configuration of a computer capable of realizing a measurement processing device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings referred to in this specification do not necessarily have accurate scales relative to actual dimensions, and some parts are exaggerated or simplified to schematically illustrate the configuration according to the present invention.

[0038] Fig. 1 is a diagram showing an example of the configuration of an object reflection characteristic measurement system 1 according to an embodiment of the present invention. The object reflection characteristic measurement system 1 shown in Fig. 1 is composed of a mobile object 100 and a measurement processing device 200. The mobile object 100 and the measurement processing device 200 are connected so as to be able to communicate with each other via wireless communication or wired communication.

[0039] The mobile body 100 is roughly composed of a transmitting antenna 10, a transmitting radio wave generating unit 11, a receiving antenna 20, a receiving power measuring unit 21, a support 30, an angle measuring unit 40, a distance measuring unit 50, a moving mechanism 110, a rotation mechanism 120, and a self-position estimating unit 130.

[0040] The transmitting antenna 10 is a directional antenna that has maximum transmission strength in a predetermined transmission direction. The transmitting antenna 10 may be a directional antenna such as a horn antenna, a dipole antenna, or an LPDA (logarithmic periodic antenna). For example, if a standard gain horn antenna is used as the transmitting antenna 10, the predetermined transmission direction with maximum transmission strength coincides with the central axis of the horn opening. Furthermore, if a dipole antenna is used as the transmitting antenna 10, the predetermined transmission direction with maximum transmission strength is positioned in a predetermined horizontal direction so that the gain varies in the horizontal direction.

[0041] The transmitting antenna 10 is configured to be able to radiate electrical energy generated by a transmission radio wave generating unit 11, which is configured with an electric field generator, an oscillator, etc., as radio waves. The frequency band and field strength (transmission power) of the radio waves radiated by the transmitting antenna 10 are not particularly limited. For example, when measuring the reflection characteristics of a measurement target T regarding radio waves used in a fifth-generation mobile communication system (hereinafter referred to as 5G), it is preferable to use radio waves in the 3.7 GHz, 4.5 GHz, or 28 GHz band used in 5G. Furthermore, it is preferable that the radio station configured by the transmitting antenna 10 and the transmission radio wave generating unit 11 be a weak radio station (a radio station with extremely weak radio waves as defined by the Radio Law).

[0042] In this specification, as an example of the reflection characteristics of the measurement object T, a case will be described in which a reflection coefficient that represents the ratio of the electric field (or magnetic field) strength of the radio wave reflected by the measurement object T to the electric field (or magnetic field) strength of the incident radio wave is calculated. However, the reflection characteristics that can be measured using the object reflection characteristic measurement system 1 are not limited to the reflection coefficient.

[0043] The receiving antenna 20 is a directional antenna that has maximum reception strength in a predetermined reception direction. The receiving antenna 20 can be a directional antenna such as a horn antenna, a dipole antenna, or an LPDA antenna, and can be an antenna similar to the transmitting antenna 10. For example, if a standard gain horn antenna is used as the receiving antenna 20, the predetermined reception direction with maximum reception strength coincides with the central axis of the horn opening. Furthermore, if a dipole antenna is used as the receiving antenna 20, the predetermined reception direction with maximum reception strength is positioned in a predetermined horizontal direction so that the gain varies in the horizontal direction.

[0044] The receiving antenna 20 is disposed so as to receive radio waves (reflected waves) emitted from the transmitting antenna 10 and reflected by the measurement object T. The radio waves received by the receiving antenna 20 are supplied as electrical energy to a received power measuring unit 21. The received power measuring unit 21 is configured to measure received power, which indicates the field strength of the radio waves received by the receiving antenna 20. The received power measuring unit 21 includes, for example, a frequency converter and an analog / digital converter, and outputs the received power of the radio waves received by the receiving antenna 20 to the measurement processing device 200.

[0045] The transmitting antenna 10 and the receiving antenna 20 are fixed and supported by a support 30 so that their relative positions are fixed. The support 30 is not particularly limited as long as it can fix the relative positions of the transmitting antenna 10 and the receiving antenna 20. As shown in FIG. 1 , the support 30 may be a flat plate member extending in a horizontal plane, and the transmitting antenna 10 and the receiving antenna 20 may be fixed to the surface of this flat plate member. Alternatively, the support 30 may be a structure in which multiple members are connected, and the transmitting antenna 10 and the receiving antenna 20 may be fixed to this structure. Such a structure may be connected to, for example, a housing that constitutes the mobile object 100.

[0046] Furthermore, it is preferable that the transmitting antenna 10 and the receiving antenna 20 are fixed so that a predetermined transmitting direction of the transmitting antenna 10 and a predetermined receiving direction of the receiving antenna 20 are oriented horizontally. Details of the arrangement of the transmitting antenna 10 and the receiving antenna 20 fixed and supported by the support body 30 will be described later with reference to Figs. 2 to 5.

[0047] The support 30 is configured to be rotatable about a predetermined rotation axis Z. The rotation axis Z, which is the rotation center of the support 30, is preferably arranged to be perpendicular to a horizontal plane that includes the predetermined transmission direction of the transmitting antenna 10 and the predetermined reception direction of the receiving antenna 20. As a result, even when the support 30 rotates around the rotation axis Z, the predetermined transmission direction of the transmitting antenna 10 and the predetermined reception direction of the receiving antenna 20 are always maintained horizontally. Furthermore, the support 30 may be connected to a housing that constitutes the mobile body 100 so as to be integral with it, and may be configured so that the support 30 also rotates when the mobile body 100 itself rotates.

[0048] Furthermore, as will be described later, it is preferable that the rotation axis Z, which is the center of rotation of the support 30, is located on the perpendicular bisector of the line segment connecting the phase center of the transmitting antenna 10 and the phase center of the receiving antenna 20.

[0049] The angle measurement unit 40 is configured to measure the rotation angle of the support 30 around the rotation axis Z. The configuration of the angle measurement unit 40 is not particularly limited, and may be, for example, a gyro sensor that detects changes in rotation and orientation of the support 30, or may be configured to output an output signal corresponding to the rotation angle of a rotor that rotates the support 30. Furthermore, if the support 30 is connected to a housing that constitutes the mobile body 100 so as to be integral with it, the angle measurement unit 40 may measure the rotation angle of the support 30 by detecting the orientation of the mobile body 100. The angle measurement unit 40 outputs the rotation angle of the support 30 around the rotation axis Z to the measurement processing device 200.

[0050] The distance measurement unit 50 is configured to measure the distance between the moving body 100 and the measurement object T. The configuration of the distance measurement unit 50 is not particularly limited, and may be a distance measurement system that can irradiate the measurement object T with laser light or ultrasonic waves and determine the distance to the measurement object T from the reflected waves.

[0051] The mobile body 100 is equipped with a movement mechanism 110 and is configured to be able to change its own position (self-position) by moving in the air or on the ground. The mobile body 100 is, for example, a UAV (unmanned aerial vehicle) or an UGV (unmanned ground vehicle), and may be controlled by a human using a controller (not shown), or may be an autonomous robot that moves by itself using AI (artificial intelligence). However, the present invention does not particularly limit the type of mobile body 100, and it may be in the form of, for example, a human-powered cart. Furthermore, it is preferable that the mobile body 100 be able to remain stationary for a certain period of time or more in a position directly facing the measurement target T, and in the case of a UAV, it is preferable that it be able to stably hover (stay stationary in the air).

[0052] The moving body 100 also includes a rotation mechanism 120. The rotation mechanism 120 has the function of rotating the support 30, to which the transmitting antenna 10 and the receiving antenna 20 are fixedly supported, about a rotation axis Z perpendicular to a horizontal plane including the phase center of the transmitting antenna 10 and the phase center of the receiving antenna 20. The rotation mechanism 120 may have the function of rotating the support 30, but may also be configured such that the housing of the moving body 100 and the support 30 are integrated, and the support 30 can be rotated by the rotation of the moving body 100 itself. For example, the rotation axis about which the rotating body 100 rotates by the rotation mechanism 120 is aligned with the rotation axis Z of the support 30, so that when the moving body 100 itself rotates, the support 30 also rotates about the rotation axis Z. The rotation mechanism 120 may also use a stepping motor that rotates by a fixed angle.

[0053] Furthermore, the moving body 100 includes a self-position estimation unit 130 that estimates the position (self-position) of the moving body 100. The self-position estimation unit 130 includes, for example, a GPS receiver that receives GPS radio waves, and outputs the position information of the moving body 100 estimated from the GPS radio waves to the measurement processing device 200.

[0054] As will be described later in this embodiment, the received power recording unit 240 of the measurement processing device 200 associates the received power of the radio waves received by the receiving antenna 20, the rotation angle of the support 30, and the position information of the mobile body 100, but these pieces of information may also be associated in the mobile body 100.

[0055] Measurement processing device 200 is generally configured to include a received power acquisition section 210, an angle acquisition section 220, a position acquisition section 230, a received power recording section 240, a storage medium 250, a maximum received power identification section 260, a reflection coefficient calculation section 270, and a reflection coefficient recording section 280. Measurement processing device 200 can be realized by, for example, a computer equipped with a CPU (Central Processing Unit), as will be described later with reference to Fig. 8.

[0056] The received power acquisition unit 210 is configured to acquire the received power of the radio waves received by the receiving antenna 20 from the received power measurement unit 21 of the mobile object 100. The received power acquisition unit 210 outputs the acquired received power to the received power recording unit 240.

[0057] The angle acquisition unit 220 is configured to acquire the rotation angle of the support body 30 about the rotation axis Z from the angle measurement unit 40 of the moving body 100. The angle acquisition unit 220 outputs the acquired rotation angle of the support body 30 to the received power recording unit 240.

[0058] The position acquisition unit 230 is configured to acquire position information of the moving object 100 from the self-position estimation unit 130 of the moving object 100. The position acquisition unit 230 outputs the acquired position information of the moving object 100 to the received power recording unit 240.

[0059] The received power recording unit 240 is configured to record (store) the received power output by the received power acquisition unit 210, the rotation angle output by the angle measurement unit 40, and the position information of the mobile object 100 output by the self-position estimation unit 130 as received power data 251, rotation angle data 252, and position data 253 in the storage medium 250, respectively. At this time, it is preferable that the received power recording unit 240 records the received power in association with the rotation angle so that it is possible to know at which rotation angle the received power is measured. Furthermore, it is preferable that the received power recording unit 240 records the received power in association with the position information of the mobile object 100 so that it is possible to know at which position the received power was measured.

[0060] The maximum received power identifying unit 260 is configured to identify the maximum received power of the receiving antenna 20 based on the received power data 251 and the rotation angle data 252 stored in the storage medium 250. The reflection coefficient calculation unit 270 is configured to calculate a reflection coefficient based on the maximum received power identified by the maximum received power identifying unit 260. The method of identifying the maximum received power of the receiving antenna 20 and the method of calculating the reflection coefficient will be described later.

[0061] The reflection coefficient recording unit 280 is configured to record (store) the reflection coefficients obtained by the calculations of the reflection coefficient calculation unit 270 in the storage medium 250 as reflection coefficient data 254. At this time, it is preferable that the reflection coefficient recording unit 280 records the reflection coefficients in association with the position information of the moving body 100 so that it is possible to know at what position the moving body 100 was located the reflection coefficient measured.

[0062] The following describes in detail the arrangement of the transmitting antenna 10 and the receiving antenna 20 fixedly supported by the support 30. Fig. 2 is a diagram for explaining the arrangement of the transmitting antenna 10 and the receiving antenna 20 in an embodiment of the present invention. Fig. 2 shows the transmitting antenna 10 and the receiving antenna 20 as viewed from above, and the transmitting antenna 10 and the receiving antenna 20 are represented by triangles (the shape of the horn portion of a horn antenna).

[0063] As described above, the transmitting antenna 10 and the receiving antenna 20 are directional antennas. Each of the transmitting antenna 10 and the receiving antenna 20 has a phase center, which can be considered a virtual point where radio waves are focused during radiation and incidence. The location of the phase center depends on the antenna type. For example, in a horn antenna, the phase center is located on the central axis of the horn opening or slightly inside the horn. In a dipole antenna positioned to achieve maximum transmission and reception strength in the horizontal direction, the phase center is located near the feed point. In Figure 2, it is assumed that the phase centers of the transmitting antenna 10 and the receiving antenna 20 are located on the center line of the horn opening. While it is preferable that the transmitting antenna 10 and the receiving antenna 20 have the same gain characteristics, they may also have different gain characteristics.

[0064] The transmitting antenna 10 and the receiving antenna 20 are arranged, for example, in the following procedure.

[0065] First, the distance d0 from the reference position of the moving body 100 to the object to be measured T during measurement is determined. The distance d0 is the ideal distance between the moving body 100 and the object to be measured T set during measurement, and can be set arbitrarily depending on the performance of the antenna, etc. As an example, the set value is not particularly limited, but is preferably about several tens of centimeters to several tens of meters. For example, the distance d0 can be set to 2 m or 4 m. Note that instead of the distance from the reference position of the moving body 100 to the object to be measured T, the propagation distance of radio waves may be determined.

[0066] Here, we assume that the object to be measured T is a vertical wall, and that an ideal measurement point P is located on the wall surface of the object to be measured T. Then, we assume that an imaginary line A is perpendicular to this wall and passes through the measurement point P, and determine a position Q on the imaginary line A that is a distance d0 away from the measurement point P.

[0067] Next, the angle θ0 to be set as the angle of incidence and the angle of reflection is determined. The set value of the angle θ0 of incidence and the angle of reflection is not particularly limited, but is preferably within the range of 1° to 45°, and more preferably within the range of 5° to 20°. For example, the angle θ0 can be set to 15°.

[0068] Imaginary line B is assumed on a horizontal plane to be perpendicular to virtual line A and pass through position Q. Imaginary lines C and D are also assumed on the horizontal plane, with measurement point P as the center and forming an angle θ0 with virtual line A. Position R, which is the intersection of virtual line B and virtual line C, and position S, which is the intersection of virtual line B and virtual line D, are then determined. Positions R and S are located symmetrically across virtual line A. The distances between position Q and the phase center (position R) of transmitting antenna 10 and the phase center (position S) of receiving antenna 20 are d0 × tan θ0. The distances between measurement point P and the phase center (position R) of transmitting antenna 10 and the phase center (position S) of receiving antenna 20 are d0 / cos θ0.

[0069] Next, transmitting antenna 10 is positioned so that its phase center is located at position R, and receiving antenna 20 is positioned so that its phase center is located at position S. Then, the predetermined transmitting direction that results in the maximum transmitting strength of transmitting antenna 10 is aligned with imaginary line C, and the predetermined receiving direction that results in the maximum receiving strength of receiving antenna 20 is aligned with imaginary line D. When standard gain horn antennas are used as transmitting antenna 10 and receiving antenna 20, the directions that result in the maximum transmitting strength and maximum receiving strength are the center lines of the horn openings.

[0070] Conventionally, it has been common to arrange the transmitting antenna 10 and the receiving antenna 20 in this manner, and orient the predetermined transmitting direction resulting in the maximum transmitting strength of the transmitting antenna 10 and the predetermined receiving direction resulting in the maximum receiving strength of the receiving antenna 20 toward the ideal measurement point P.

[0071] In this embodiment, the deviation angle φ sand adjust the orientations of the transmitting antenna 10 and the receiving antenna 220. Specifically, for the transmitting antenna 10, from a state in which a predetermined transmitting direction in which the transmitting antenna 10 has the maximum transmission strength is aligned with the imaginary line C, the deviation angle φ is adjusted around the position R where the phase center of the transmitting antenna 10 is located. s 2) away from the receiving antenna 20. In addition, the receiving antenna 20 is rotated by a deviation angle φ from the state where the predetermined receiving direction in which the receiving antenna 20 has the maximum receiving strength is aligned with the imaginary line D, with the position S where the phase center of the receiving antenna 20 is located as the center. s 2) away from the transmitting antenna 10. Then, the transmitting antenna 10 and the receiving antenna 20 are fixed to the support 30 in this arrangement position.

[0072] Deviation angle φ s Although the set value of is not particularly limited, it is preferably in the range of 1° to 30°, and more preferably in the range of 1° to 15°. For example, the deviation angle φ s = 3.3°. s and the offset angle φ at the transmitting antenna 10 s are preferably the same angle, but may be different angles.

[0073] By the above procedure, the midpoint (position Q) of the line segment connecting the phase center (position R) of the transmitting antenna 10 and the phase center (position S) of the receiving antenna 20 is located at a distance d0 from the ideal measurement point P. The predetermined transmission direction in which the transmitting antenna 10 has the maximum transmission strength is determined by the deviation angle φ from the phase center (position R) of the transmitting antenna 10 to the imaginary line C connecting the phase center (position R) of the transmitting antenna 10 and the measurement point P. s The predetermined receiving direction in which the receiving antenna 20 has the maximum receiving strength is determined by an angle φ sThe antennas 10 and 20 are oriented so as to be shifted in a direction away from the transmitting antenna 10 by a distance of 10. Furthermore, since the transmitting antenna 10 and the receiving antenna 20 are fixed to the support 30, the relative positions of the two antennas are fixed.

[0074] The above-described procedure for arranging the transmitting antenna 10 and the receiving antenna 20 is merely an example, and the procedure is not particularly limited as long as the transmitting antenna 10 and the receiving antenna 20 are ultimately fixed in the arranged and oriented state as shown in Figure 2.

[0075] Furthermore, the rotation axis Z of the support 30 is preferably positioned on the virtual line A passing through the measurement point P and the position Q, and more preferably positioned at the position Q that is a distance d0 away from the measurement point P. The reference position for measuring the distance to the measurement object T is also preferably positioned on the virtual line A passing through the measurement point P and the position Q, and more preferably positioned at the position Q that is a distance d0 away from the measurement point P. However, since the object reflection characteristic measurement system 1 in this embodiment can reduce the effects of errors in the distance and angle to the measurement object T, as will be described later, the position of the rotation axis Z and the reference position for distance measurement do not need to be positioned strictly on the virtual line A or at the position Q.

[0076] The effect of reducing distance errors achieved by this embodiment will be described with reference to Figures 3 and 4. Figures 3 and 4 are diagrams for explaining the effect of reducing distance errors achieved by the embodiment of the present invention. Figure 3 illustrates a case where the distance between moving body 100 and measurement object T is closer than the ideal distance d0, and Figure 4 illustrates a case where the distance between moving body 100 and measurement object T is farther than the ideal distance d0.

[0077] When measuring the reflection coefficient of the measurement target T, it is desirable to arrange the transmitting antenna 10 and the receiving antenna 20 so that the distance from the reference position of the moving body 100 to the measurement target T is the above-mentioned ideal distance d0. However, it is not necessarily easy to accurately arrange the transmitting antenna 10 and the receiving antenna 20 so that this distance is the ideal distance d0, and there is a possibility that a slight deviation in the distance occurs.

[0078] Consider the case where the mobile object 100 is placed in a position close to the measurement target T, and is closer by an infinitesimal distance ε than the ideal distance d0 (distance = d0 - ε). In this case, as shown in Fig. 3, the approach of the measurement target T shortens the propagation distance of the radio waves from the transmitting antenna 10 to the receiving antenna 20, and the free space loss, which represents the attenuation of the radio waves, becomes smaller.

[0079] Furthermore, the ideal measurement point P is located on the far side (distal side) of the wall surface of the measurement object T. As a result, the direction connecting the phase center of the transmitting antenna 10 and the reflection point of the radio wave, and the direction connecting the phase center of the receiving antenna 20 and the reflection point of the radio wave, are directions (angle φ = φ) that move away from the predetermined transmitting direction with the maximum transmission strength and the predetermined receiving direction with the maximum reception strength, respectively. s +δφ), the antenna gain, which indicates the sensitivity of the antenna, becomes smaller. s is the antenna gain G of the transmitting antenna 10 TX (φ) and the antenna gain G of the receiving antenna 20 RX (φ) is an angle that satisfies the following formula.

[0080]

number

[0081] In this way, when the mobile object 100 approaches the measurement target T, the free space loss is reduced, and the received power of the radio waves received by the receiving antenna 20 is greater than when the mobile object 100 is the ideal distance d0 away. However, the antenna gain is reduced, and the received power of the radio waves received by the receiving antenna 20 is less than when the mobile object 100 is the ideal distance d0 away. As a result, the change in the received power at the receiving antenna 20 is canceled out.

[0082] Consider the case where the mobile object 100 is placed at a distance from the object to be measured T, and is farther away from the ideal distance d0 by an infinitesimal distance ε (distance = d0 + ε). In this case, as shown in Fig. 4, the distance of the object to be measured T increases the propagation distance of the radio waves from the transmitting antenna 10 to the receiving antenna 20, and the free space loss, which represents the attenuation of the radio waves, increases.

[0083] Furthermore, the ideal measurement point P is located on the near side (proximal side) of the wall surface of the measurement object T. As a result, the direction connecting the phase center of the transmitting antenna 10 and the reflection point of the radio wave, and the direction connecting the phase center of the receiving antenna 20 and the reflection point of the radio wave, are respectively in the direction approaching the predetermined transmitting direction with the maximum transmission strength and the predetermined receiving direction with the maximum reception strength (angle φ = φ s -δφ), the antenna gain, which indicates the sensitivity of the antenna, increases.

[0084] In this way, when the moving body 100 moves away from the measurement target T, the free space loss increases, and the received power of the radio waves received by the receiving antenna 20 becomes smaller compared to when the moving body 100 is the ideal distance d0 away. However, the antenna gain increases, and the received power of the radio waves received by the receiving antenna 20 becomes larger compared to when the moving body 100 is the ideal distance d0 away. As a result, the change in the received power at the receiving antenna 20 is canceled out.

[0085] In this way, in this embodiment, the direction of the transmitting antenna 10 and the direction of the receiving antenna 20 are intentionally shifted by the shift angle φ, so that changes in the received power due to small changes in distance are canceled out whether the distance between the moving body 100 and the object to be measured T is closer or farther than the assumed ideal distance d0. As a result, the allowable error range of the distance to the object to be measured T is increased, and the influence of errors in the distance to the object to be measured T can be reduced.

[0086] The effect of reducing angle errors achieved by this embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram for explaining the effect of reducing angle errors achieved by the embodiment of the present invention. Fig. 5 illustrates a case where the orientation of the moving object 100 is shifted in one direction (towards the receiving antenna 20).

[0087] When measuring the reflection coefficient of a measurement object, it is desirable that the mobile body 100 directly faces the measurement object T, as shown in Fig. 2. In other words, it is ideal to position the mobile body 100 so that the perpendicular bisector (imaginary line A) of the line segment connecting the phase center of the transmitting antenna 10 and the phase center of the receiving antenna 20 is perpendicular to the wall surface of the measurement object T. However, it is not necessarily easy to have the mobile body 100 directly face the measurement object T without any deviation, and there is a possibility that a slight deviation in angle may occur.

[0088] Let us consider a case where the moving body 100 is not directly facing the measurement target T, but is oriented in one direction (toward the receiving antenna 20). In this case, the transmitting antenna 10 and the receiving antenna 20 are not arranged in symmetrical positions, and as shown in FIG. 5, the effective transmitting direction of the transmitting antenna 10 (angle φ TX ) becomes smaller, while the effective receiving direction of the receiving antenna 20 (angle φ RX ) becomes larger (angle φ TX <Angle φ RX At this time, the moving body 100 is in an ideal state where it faces the measurement target T directly without any deviation (angle φ TX = angle φ RXIn addition, when the direction of the moving object 100 is shifted to the other direction (toward the transmitting antenna 10) (angle φ TX >Angle φ RX Similarly, the ideal state (angle φ TX = angle φ RX In this state, the reception power of the radio waves received by the receiving antenna 20 is smaller than in the state (2).

[0089] As shown in Fig. 5, when a virtual line Bz passing through the phase center of the transmitting antenna 10 and the phase center of the receiving antenna 20 is considered, the ideal measurement state is when the virtual line Bz and the virtual line B coincide. For example, if the transmitting antenna 10 and the receiving antenna 20 have the same gain characteristics, the received power of the radio wave received by the receiving antenna 20 is represented by an upwardly convex (mountain-shaped) graph as shown in Fig. 6 with respect to the angle ξ formed by the virtual line Bz and the virtual line B, and is maximum when the angle ξ = 0°, which is the ideal measurement state. Note that even if the transmitting antenna 10 and the receiving antenna 20 have different gain characteristics, for example, the angle φ set in the transmitting antenna 10 TX and the angle φ set at the receiving antenna 20 RX By adjusting these angles to appropriate angles, it is possible to appropriately set the reception power of the radio waves received by the receiving antenna 20 to be maximum when the angle ξ=0°.

[0090] Considering the above behavior, in this embodiment, the support 30, to which the transmitting antenna 10 and the receiving antenna 20 are fixedly supported, is rotated around the rotation axis Z, and the received power of the receiving antenna 20 is acquired at a plurality of different rotation angles to search for the point at which the received power is maximum. Then, the maximum received power of the receiving antenna 20 is identified, and the reflection coefficient of the object to be measured T is calculated based on this maximum received power. As a result, even if the moving body 100 is not directly facing the object to be measured T and there is a deviation in the initial angle, by rotating the support 30 around the rotation axis Z and searching for the maximum received power, it becomes possible to acquire the received power in an ideal measurement state (angle ξ = 0°) and accurately calculate the reflection coefficient of the object to be measured T.

[0091] The method for identifying the maximum received power is not particularly limited, but for example, the maximum value of the received power obtained by rotating the support 30 and scanning the measurement object T may be identified as the maximum received power. Alternatively, a regression curve of the received power obtained by rotating the support 30 and scanning the measurement object T may be found, and the value of the peak of the regression curve may be identified as the maximum received power.

[0092] The mechanism for reducing angle errors does not interfere with the mechanism for reducing distance errors described above, and the effects of the two mechanisms do not cancel each other out. Therefore, the mechanism for reducing distance errors and the mechanism for reducing angle errors can be used together.

[0093] Next, the flow of processing in this embodiment will be described below. Fig. 7 is a flowchart showing the flow of processing in this embodiment of the present invention.

[0094] First, the mobile object 100 moves to the vicinity of a specific measurement position within the measurement area (step S101) and stops at a position a distance d0 away from the measurement object T (step S103). As described above, the present invention has the effect of reducing distance errors, and is capable of reducing the influence of errors in the distance between the mobile object 100 and the measurement object T. Ideally, the distance between the mobile object 100 and the measurement object T is exactly d0. However, in the present invention, even if this distance deviates to some extent, the change from the received power at the ideal distance d0 is small, and the reflection coefficient can be calculated with high accuracy. For this reason, in step S103, the mobile object 100 does not necessarily have to be positioned exactly at a position a distance d0 away from the measurement object T.

[0095] Next, while rotating the support 30, radio waves (transmitted waves) are emitted from the transmitting antenna 10 to the measurement object T, and the received power of the radio waves (reflected waves) received by the receiving antenna 20 is measured at multiple different rotation angles (step S105). At this time, in order to search for an ideal measurement state, the rotation direction of the support 30 may be repeatedly reversed to scan a wide range of the measurement object T. The received power and rotation angle are sent from the mobile object 100 to the measurement processing device 200. The received power recording unit 240 of the measurement processing device 200 stores the received power acquired from the mobile object 100 in the storage medium 250 in association with the rotation angle of the support 30 (step S107).

[0096] The received power obtained at a plurality of different rotation angles has a relationship as shown in Fig. 6. The maximum received power identifying unit 260 identifies the maximum received power measured at a specific measurement position based on the received power and rotation angle stored in the storage medium 250 (step S109).

[0097] The reflection coefficient calculation unit 270 calculates a reflection coefficient at a specific measurement position based on the maximum received power identified by the maximum received power identification unit 260 (step S111). The reflection coefficient calculation unit 270 may calculate the reflection coefficient using an existing method. As an example, the reflection coefficient calculation unit 270 calculates the ratio of the electric field of the wave incident on the measurement object T (transmission power of the transmitting antenna 10) to the electric field of the wave reflected from the measurement object T (maximum received power of the receiving antenna 20), and further calculates the ratio with a reflection coefficient (reflection coefficient ≈ 1) measured in advance using a metal plate such as an aluminum plate or a copper plate with high conductivity, thereby calculating the reflection coefficient at the specific measurement position.

[0098] The reflection coefficient recording unit 280 stores the reflection coefficients calculated by the reflection coefficient calculation unit 270 in the storage medium 250 in association with the position information of the moving object 100 (step S113).

[0099] By executing the above-described processing of steps S101 to S113, it is possible to calculate the reflection coefficient at a specific measurement position. The processing of steps S101 to S113 is executed for each measurement position included in a predetermined measurement target area ("No" in step S115). On the other hand, when the calculation of reflection measurements has been completed for all of the measurement positions in the measurement target area, the processing ends ("Yes" in step S115).

[0100] In the flowchart shown in FIG. 7, the process of measuring the received power (the process of steps S101 to S107) is immediately followed by the process of calculating the reflection coefficient (the process of steps S109 to S113). However, it is also possible to collect measurement data by performing only the process of measuring the received power for all measurement positions within the measurement target area, and then perform the process of calculating the reflection coefficient afterwards using the collected measurement data.

[0101] By storing the reflection coefficient data 254 obtained in this embodiment in association with the position data 253 of the mobile object 100 in the storage medium 250, the reflection coefficient data 254 can be used for various purposes. For example, it is possible to identify the measurement position from the position data 253 of the mobile object 100, and the measurement position and reflection coefficients can be used to perform a radio wave propagation simulation for building a wireless network. Specifically, in an environment where wireless communication equipment is installed, the method according to this embodiment can be used to actually measure the reflection coefficient in real space, and the measured value of the reflection coefficient can be used to perform a radio wave propagation simulation, thereby obtaining more accurate simulation results. Furthermore, by using the simulation results, it is possible to design the layout of wireless communication equipment to improve the quality of wireless communication, thereby enabling the construction of a high-quality communication infrastructure.

[0102] The functions of the measurement processing device 200 in this embodiment are realized, for example, by the hardware configuration described below. Figure 8 is a schematic block diagram showing an example configuration of a computer capable of realizing the measurement processing device 200 in this embodiment of the present invention.

[0103] 8 includes, as an example, a processor 810, a memory 820, a storage 830, an input / output interface 840, and a communication interface 850, and these components are connected via a bus 860. As the computer 800, for example, a personal computer, a tablet, a mobile information terminal such as a smartphone, etc. can be used.

[0104] Processor 810 is hardware that executes various instructions written in a program and realizes and controls various functions in computer 800. Processor 810 may be, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor) or GPU (Graphics Processing Unit) that performs data processing specialized for a specific purpose, or an FPGA (Field Programmable Gate Array) that offers a high degree of design freedom.

[0105] The memory 820 is a volatile memory that temporarily stores programs and data executed by the computer 800, and is, for example, a main storage device such as a RAM (Random Access Memory).

[0106] The storage 830 is, for example, an auxiliary storage device such as a magnetic disk such as an HDD (hard disk drive), a semiconductor memory such as an SSD (solid state drive), a magneto-optical disk, an optical disk, etc. The storage 830 may be connected via an input / output interface 840, or may be located in a position accessible via the communication interface 850.

[0107] The storage 830 is capable of storing a program and data in which the processing procedures of this embodiment are written as program instructions. The processor 810 reads the program according to this embodiment from the storage 803, loads it on the memory 820, and executes the program instructions, thereby enabling the computer 800 to implement the functions according to this embodiment.

[0108] The storage 830 stores a received power acquisition program 910, an angle acquisition program 920, a position acquisition program 930, a received power recording program 940, a maximum received power identification program 960, a reflection coefficient calculation program 970, and a reflection coefficient recording program 980. The processor 810 executes the received power acquisition program 910, the angle acquisition program 920, the position acquisition program 930, the received power recording program 940, the maximum received power identification program 960, the reflection coefficient calculation program 970, and the reflection coefficient recording program 980, thereby realizing the received power acquisition unit 210, the angle acquisition unit 220, the position acquisition unit 230, the received power recording unit 240, the maximum received power identification unit 260, the reflection coefficient calculation unit 270, and the reflection coefficient recording unit 280 shown in FIG.

[0109] The storage 830 is also capable of storing data in this embodiment. The storage 830 corresponds to the storage medium 251 shown in Fig. 1, and the received power data 251, the rotation angle data 252, the position data 253, and the reflection coefficient data 254 can be stored in the storage 830.

[0110] The input / output interface 840 has a function of receiving information input from a user and a function of outputting information to the user. The input / output interface 840 is configured to provide connections with various devices, such as user input devices such as a mouse 841 and a keyboard 842, information collection devices such as a camera 843 and a microphone 844, and information output devices such as a display 845 and a speaker 846. A touch panel display having a display function and an information input function may be connected to the input / output interface 840.

[0111] The communication interface 850 has a function for the computer 800 to communicate with other computers, such as a computer installed in the mobile object 100. The communication interface 850 may be configured to enable the computer 800 to access other computers via a network 851. Examples of the network 851 include a LAN (local area network), a WAN (wide area network), the Internet, etc. The communication interface 850 may also be configured to enable direct communication with other computers. There are no particular limitations on the communication method used by the communication interface 850, and either a packet communication method or a circuit switching method may be used, and either wired communication or wireless communication may be used.

[0112] The functions and effects of the present invention will be described below.

[0113] As described above, the object reflection characteristic measurement system 1 in the embodiment of the present invention is configured to measure the reflection characteristics of the measurement object T. The reflection characteristics of the measurement object T include the reflection coefficient of the measurement object T.

[0114] The object reflection characteristic measuring system 1 in an embodiment of the present invention includes a transmitting antenna 10 that has directivity with maximum transmission strength in a predetermined transmitting direction and irradiates a transmission wave onto the object to be measured T, a receiving antenna 20 that has directivity with maximum reception strength in a predetermined receiving direction and receives a reflected wave from the object to be measured T, a support 30 that fixedly supports the transmitting antenna 10 and the receiving antenna 20 so that the relative positions of the transmitting antenna 10 and the receiving antenna 20 are fixed, a received power measuring unit 21 that measures the received power of the reflected wave received by the receiving antenna 20, and a reflection characteristic calculation unit (reflection coefficient calculation unit 270) that calculates the reflection characteristics of the object to be measured T based on the received power of the reflected wave.

[0115] In the object reflection characteristic measuring system 1 according to the embodiment of the present invention, a predetermined transmission direction in which the transmission strength of the transmitting antenna 10 is maximum is determined by a first predetermined angle (for example, angle φ ) with respect to a line (a virtual line C shown in FIG. 2 ) connecting the phase center of the transmitting antenna 10 and an ideal measurement point P that is a predetermined distance away from the phase center of the transmitting antenna 10. S ) in a direction away from the receiving antenna 20. Also, the predetermined receiving direction in which the receiving antenna 20 has the maximum receiving strength is offset by a second predetermined angle (for example, angle φ) with respect to the line (the imaginary line D shown in FIG. 2) connecting the phase center of the receiving antenna 20 and an ideal measurement point P that is a predetermined distance away from the phase center of the receiving antenna 20. S ) away from the transmitting antenna 10.

[0116] This reduces the influence of positional errors relative to the measurement object T, and enables accurate measurement of the reflection characteristics of the measurement object T with a simple configuration. In particular, for the transmitting antenna 10 and the receiving antenna 20, a predetermined transmitting direction with maximum transmission strength and a predetermined receiving direction with maximum reception strength are set at a first predetermined angle and a second predetermined angle (for example, the first predetermined angle and the second predetermined angle are the same angle φ S ), the tolerance for error in the distance to the measurement object T can be increased, and the influence of the error in the distance to the measurement object T can be reduced.

[0117] In addition, the object reflection characteristic measuring system 1 in this embodiment of the present invention has a rotation mechanism 120 that rotates the support 30, to which the transmitting antenna 10 and the receiving antenna 20 are fixedly supported, around a rotation axis Z that is perpendicular to a horizontal plane including the phase center of the transmitting antenna 10 and the phase center of the receiving antenna 20.

[0118] This allows the transmitting antenna 10 and receiving antenna 20, which are fixedly supported on the support body 30, to rotate together with the rotation axis Z as the center of rotation, and the receiving antenna 20 can receive reflected waves at multiple different rotation angles to obtain the received power of the reflected waves.

[0119] In addition, the object reflection characteristic measuring system 1 in this embodiment of the present invention has a maximum received power identifying unit 260 that acquires the received power of the reflected wave received by the receiving antenna 20 at multiple different rotation angles by rotating the support 30, and identifies the maximum received power at which the received power of the reflected wave is maximum.

[0120] This makes it possible to identify the maximum received power of the reflected wave from the received power of the reflected wave acquired at a plurality of different rotation angles. In particular, by acquiring the received power of the reflected wave at a plurality of different rotation angles while rotating the transmitting antenna 10 and the receiving antenna 20 together around the rotation axis Z as the center of rotation, it becomes possible to allow for angular deviation of the initial positions of the transmitting antenna 10 and the receiving antenna 20 with respect to the object to be measured, and to reduce the influence of angle error with respect to the object to be measured T.

[0121] The object reflection characteristic measuring system 1 according to the embodiment of the present invention has a moving mechanism 110 that moves a support to which a transmitting antenna 10 and a receiving antenna 20 are fixedly supported.

[0122] This allows the transmitting antenna 10 and the receiving antenna 20 to be arranged on a mobile body having a moving mechanism 110 and to be moved, making it possible to easily and freely change the measurement position.

[0123] In addition, the object reflection characteristic measuring method in an embodiment of the present invention includes a procedure for measuring the reflection characteristics of the object T to be measured, and includes the steps of preparing the above-mentioned transmitting antenna 10 and receiving antenna 20, fixing and supporting the transmitting antenna 10 and receiving antenna 20 to a support 30 so that the relative positions of the transmitting antenna 10 and receiving antenna 20 are fixed, measuring the received power of the reflected wave received by the receiving antenna 20, and calculating the reflection characteristics of the object T to be measured based on the received power of the reflected wave.

[0124] In the object reflection characteristic measuring method according to the embodiment of the present invention, when the transmitting antenna 10 is fixedly supported on the support 30, a predetermined transmitting direction in which the transmitting antenna 10 has the maximum transmission strength is determined by dividing the phase center of the transmitting antenna 10 by a first predetermined angle (for example, an angle φ S) in a direction away from the receiving antenna 20. When the receiving antenna 20 is fixed to and supported by the support 30, the predetermined receiving direction in which the receiving antenna 20 has the maximum reception strength is determined by shifting the phase center of the receiving antenna 20 by a second predetermined angle (for example, angle φ S ) in a direction away from the transmitting antenna 10.

[0125] This reduces the influence of positional errors relative to the measurement object T, and enables accurate measurement of the reflection characteristics of the measurement object T with a simple configuration. In particular, for the transmitting antenna 10 and the receiving antenna 20, a predetermined transmitting direction with maximum transmission strength and a predetermined receiving direction with maximum reception strength are set at a first predetermined angle and a second predetermined angle (for example, the first predetermined angle and the second predetermined angle are the same angle φ S ), the tolerance for error in the distance to the measurement object T can be increased, and the influence of the error in the distance to the measurement object T can be reduced.

[0126] The present invention also provides a processing procedure executed by a computer implemented in the moving object 100, and a method related to the processing procedure executed by a computer implemented in the measurement processing device 200. Furthermore, the present invention also provides a program for causing a computer to execute the above processing procedure.

[0127] The present invention is not limited to the above-described embodiments, and various modifications and design changes are included within the technical scope of the present invention without departing from the technical idea of ​​the present invention. [Explanation of symbols]

[0128] 1. Object reflection characteristics measurement system 10 transmitting antennas 11 Transmission radio wave generator 20 receiving antenna 21 Received power measurement section 30 Support 40 Angle measurement unit 50 Distance measurement unit 100 Mobile 110 Moving mechanism 120 Rotation Mechanism 130 Self-position estimation part 200 Measurement processing device 210 Received power acquisition unit 220 Angle acquisition section 230 Position acquisition part 240 Received power recording unit 250 Storage medium 251 Received Power Data 252 rotation angle data 253 location data 254 reflection coefficient data 260 Maximum received power determination unit 270 Reflection coefficient calculation unit 280 Reflection coefficient recording unit 800 computers 810 processor 820 memory 830 Storage (storage media) 840 Input / Output Interface 841 Mouse 842 keyboard 843 Camera 844 microphone 845 Display 846 Speaker 850 Communication Interface 860 Bus 910 Received Power Acquisition Program 920 Angle Acquisition Program 930 Location Acquisition Program 940 Received Power Recording Program 960 Maximum Received Power Identification Program 970 Reflection Coefficient Calculation Program 980 Reflection Coefficient Recording Program T Measurement object

Claims

1. An object reflection characteristic measurement system for measuring reflection characteristics of a measurement object, a transmitting antenna having directivity with maximum transmission strength in a predetermined transmission direction, which irradiates a transmission wave onto an object to be measured; a receiving antenna having directivity with maximum reception strength in a predetermined reception direction, and receiving a reflected wave from the object to be measured; a support that fixes and supports the transmitting antenna and the receiving antenna so that the relative positions of the transmitting antenna and the receiving antenna are fixed; a received power measurement unit that measures the received power of the reflected wave received by the receiving antenna; a reflection characteristic calculation unit that calculates the reflection characteristic of the object to be measured based on the received power of the reflected wave, the predetermined transmission direction of the transmitting antenna is oriented at a first predetermined angle from the phase center of the transmitting antenna as a reference, in a direction away from the receiving antenna, with respect to a line connecting the phase center of the transmitting antenna and an ideal measurement point a predetermined distance away from the phase center of the transmitting antenna; The object reflection characteristic measurement system is characterized in that the predetermined receiving direction of the receiving antenna is oriented at a second predetermined angle, with respect to a straight line connecting the phase center of the receiving antenna and the ideal measurement point a predetermined distance away, in a direction away from the transmitting antenna.

2. 2. The object reflection characteristic measuring system according to claim 1, further comprising a distance measuring unit that is arranged to be fixed to the support and that measures the distance to the object to be measured.

3. 3. The object reflection characteristic measuring system according to claim 1, further comprising a rotation mechanism that rotates the support, to which the transmitting antenna and the receiving antenna are fixedly supported, about a rotation axis that is perpendicular to a horizontal plane including the phase center of the transmitting antenna and the phase center of the receiving antenna.

4. 4. The object reflection characteristic measuring system according to claim 3, wherein the rotation axis is located on the perpendicular bisector of a line segment connecting the phase center of the transmitting antenna and the phase center of the receiving antenna.

5. 5. The object reflection characteristic measuring system according to claim 3, further comprising a maximum received power determining unit that obtains the received power of the reflected wave received by the receiving antenna at a plurality of different rotation angles by rotating the support, and determines the maximum received power at which the received power of the reflected wave is maximum.

6. 6. The object reflection characteristic measuring system according to claim 5, wherein the reflection characteristic calculation unit calculates the reflection characteristic of the object to be measured based on the maximum received power.

7. 7. The object reflection characteristic measuring system according to claim 3, further comprising an angle measuring unit for measuring a rotation angle of the support body around the rotation axis as a center of rotation.

8. 8. The object reflection characteristic measuring system according to claim 7, further comprising a received power recording unit that records the received power of the reflected wave received by the receiving antenna in a predetermined storage medium in association with the rotation angle of the support.

9. 9. The object reflection characteristic measuring system according to claim 1, further comprising a movement mechanism for moving the support to which the transmitting antenna and the receiving antenna are fixedly supported.

10. 10. The object reflection characteristic measuring system according to claim 9, further comprising a self-locating unit for identifying the position of the support on which the transmitting antenna and the receiving antenna are fixedly supported.

11. The object reflection characteristic measuring system according to claim 10, further comprising a reflection characteristic recording unit that records the reflection characteristics of the object to be measured in a predetermined storage medium in association with the positions of the support on which the transmitting antenna and the receiving antenna are fixedly supported.

12. 12. The object reflection characteristic measuring system according to claim 1, wherein the reflection characteristic of the object to be measured is measured as a reflection coefficient of the object to be measured.

13. An object reflection characteristic measurement method for measuring reflection characteristics of a measurement object, comprising: preparing a transmitting antenna having directivity with maximum transmission strength in a predetermined transmission direction and irradiating a transmission wave onto a measurement object; preparing a receiving antenna having directivity with maximum reception strength in a predetermined reception direction and configured to receive a reflected wave from the object to be measured; a step of fixing and supporting the transmitting antenna and the receiving antenna on a support so that the relative positions of the transmitting antenna and the receiving antenna are fixed; measuring the received power of the reflected wave received by the receiving antenna; calculating the reflection characteristics of the object to be measured based on the received power of the reflected wave, When the transmitting antenna is fixedly supported on the support, the predetermined transmission direction of the transmitting antenna is shifted by a first predetermined angle from the phase center of the transmitting antenna as a reference in a direction away from the receiving antenna with respect to a line connecting the phase center of the transmitting antenna and an ideal measurement point separated by a predetermined distance, a second predetermined angle from the phase center of the receiving antenna relative to a line connecting the phase center of the receiving antenna and the ideal measurement point a predetermined distance away from the transmitting antenna when the receiving antenna is fixedly supported on the support body;

Images