Relative position and relative posture measurement device, relative position and relative posture adjustment device, and antenna direction adjustment system

Abstract

To detect a generated angle and position deviation with high real-time property even when aligning antennas between a mobile body and a stationary station or between mobile bodies.SOLUTION: A relative position and relative posture measurement device comprises: two or more propagation phase difference detection sections respectively having a phase difference detection antenna, a transmitter for transmitting a radio wave via the phase difference detection antenna, and a receiver for receiving the radio wave via the phase difference detection antenna; a phase detection section for detecting respective phase differences based on a transmission-time propagation wave phase of the transmitted radio wave and reception-time propagation wave phases of the respective radio waves transmitted from the other one or more propagation phase difference detection sections; and a position angle deviation calculation section for calculating positions or directions of measurement objects where a propagation phase difference detection antenna is arranged, based on the phase differences.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a relative position and relative attitude measurement device, a relative position and relative attitude adjustment device, and an antenna direction adjustment system that can measure deviations from an ideal position and deviations from an ideal angle by measuring the phase difference between two objects over multiple paths. [Background technology]

[0002] In recent years, high-speed, large-volume data transfer has become possible through broadband communications using millimeter waves and terahertz waves, which are frequencies between 28 GHz and 300 GHz and even higher. This is because as the frequency band used increases, the bandwidth becomes wider and it becomes possible to improve the transfer rate.

[0003] On the other hand, broadband communication has led to strong attenuation of radio waves, making it difficult to achieve long propagation distances. For this reason, it is common to use aperture antennas such as horn antennas and parabolic antennas as high-gain antennas to compensate for this attenuation. This has created a need to handle beam-shaped radio waves with strong directionality due to the linearity of the radio waves themselves. If such high-gain antennas are not precisely aligned on both the transmitting and receiving sides, there is a concern that the position and angle misalignment between the gain antennas will reduce the radio wave reception strength, affecting communication quality.

[0004] In addition, when aligning antennas between a mobile body and a fixed station, or between mobile bodies, it is necessary to perform feedback control with high real-time accuracy for the angle and positional deviation that occurs. For this reason, the control techniques disclosed in Patent Documents 1 to 3 were required.

[0005] Patent Document 1 discloses a wireless device that observes the received signal strength indicator (RSSI) of the communication radio wave itself in an antenna that handles a highly linear frequency band such as millimeter waves, and optimizes the antenna direction so that the strength is maximized. Patent Document 2 discloses a base station device that installs a GPS positioning device on either or both of the transmitting and receiving sides, calculates an ideal opposing angle based on the respective positioning information, and optimizes the antenna direction accordingly. Patent Document 3 discloses an antenna direction adjustment system that uses real-time kinematic positioning using GPS and also uses an attitude sensor such as a gyro to adjust the direction of a 50 GHz band antenna. Patent Document 3 also discloses an antenna direction adjustment system that enables communication from a ground antenna to an aircraft flying in the sky. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2004-112554 A [Patent Document 2] JP 2017-50599 A [Patent Document 3] JP 2012-220318 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the techniques disclosed in Patent Documents 1 and 2 are premised on adjusting the direction of an antenna mounted on a stationary object, and do not assume alignment of antennas between moving objects. Therefore, the techniques disclosed in Patent Documents 1 and 2 have a problem in that they cannot align antennas between moving objects with high accuracy.

[0008] In addition, in Patent Document 3, the direction of a directional transmission radio wave is scanned and the direction is determined from the timing of reception, but there is a problem in that the accuracy is relatively low.

[0009] Currently, visual inspection using a target scope or manual adjustment using RSSI, etc., is generally used, but this places a heavy burden on the operator and makes it difficult to achieve a highly accurate facing state.

[0010] In addition, in antenna alignment using RSSI, even a slight angle shift may cause beam misalignment to the extent that RSSI cannot be detected in the first place, in the case of very narrowed beams of millimeter waves or terahertz waves. For example, even an angle shift of 0.1 degrees corresponds to a position shift of 17 cm at a distance of 100 m. In this case, if the narrowed beam is only a few cm, the antenna cannot detect RSSI, and it cannot be used for position adjustment. In addition, in antenna alignment using RSSI, since it is not possible to know exactly what the RSSI will be when the antenna is in the optimal facing position or angle, the antenna direction is adjusted while searching for the maximum value. This causes problems such as poor responsiveness and being unsuitable for alignment of moving objects, which require feedback control with higher real-time performance. In addition, in antenna alignment using RSSI, since it is a search for the maximum value, there is a concern that it may settle on a local optimum solution around the side lobe, etc., and there is a problem that the main lobe may not be captured and the best communication quality may not be provided. In particular, in the case of moving objects, adjustment is required for a total of six degrees of freedom, three axes of position and three axes of angle, and adjusting it from the RSSI, which is a scalar quantity, requires many trials, which sacrifices responsiveness and makes it difficult to achieve.

[0011] In addition, when using GPS positioning to face each other using their own positioning information, it is necessary to share each other's positioning information in some way, and an additional communication system is required, which makes the system complicated. In particular, when mobile communication is required, there is a problem that it cannot be used in an environment where mobile communication is not available around the antenna installation location. In addition, there is a problem that GPS positioning cannot be aligned with high precision because a positioning error of several meters occurs. In addition, there is a problem that GPS positioning cannot be used in places where GPS satellites are blind spots, under bridges, indoors, etc. In addition, GPS positioning generally uses a gyro to calculate angles, but there is a problem that errors occur due to gyro drift.

[0012] The present invention has been devised in consideration of the above-mentioned problems, and an object of the present invention is to provide a relative position and relative attitude measuring device, a relative position and relative attitude adjustment device, and an antenna direction adjustment system that are capable of detecting the angle and positional deviation that occurs with greater real-time accuracy, even when aligning the antennas of a mobile body and a fixed station, or between mobile bodies. [Means for solving the problem]

[0013] The relative position and relative attitude measuring device according to a first aspect of the present invention is characterized in that it comprises two or more propagation phase difference detection units having a phase difference detection antenna, a transmitter that transmits radio waves via the phase difference detection antenna, and a receiver that receives the radio waves via the phase difference detection antenna, a phase detection unit that detects a phase difference between the carrier phase at the time of transmission and the carrier phase at the time of reception based on the carrier phase at the time of transmission of the radio waves transmitted by the transmitter and the carrier phase at the time of reception of each of the radio waves transmitted from one or more other propagation phase difference detection units and received by the receiver, and a position angle deviation calculation unit that calculates a position or orientation of a measured object on which the propagation phase difference detection antenna is provided based on the respective phase differences detected by the phase detection unit.

[0014] The relative position and relative orientation measuring device according to a second invention is characterized in that, in the first invention, the phase detection unit repeatedly detects each of the phase differences and detects a time-varying value of each of the phase differences, and the position angle deviation calculation unit calculates a change value of a position or orientation of the object to be measured based on the each of the change values ​​detected by the phase detection unit.

[0015] The wireless communication system according to a third aspect of the present invention is characterized in that, in the first aspect, a displacement magnifying mechanism is provided which fixes or supports the object to be measured and increases the distance between the phase difference detection antenna attached to the object to be measured and another phase difference detection antenna.

[0016] The relative position and relative attitude measuring device of the fourth invention is characterized in that, in the first invention, the propagation phase difference detection unit has either a transmitter that can switch between two or more frequencies of radio waves to be transmitted, or a transmitter that can vary the frequency of the radio waves to be transmitted discretely or continuously.

[0017] A relative position and relative orientation measuring device according to a fifth aspect of the present invention is characterized in that in the first aspect, it further includes a sensor that measures physical information related to a position or orientation of the object to be measured, and the position angle deviation calculation unit calculates the position or the orientation based on the phase difference and the physical information measured by the sensor.

[0018] The relative position and relative attitude adjustment device of the sixth aspect of the present invention is a relative position and relative attitude adjustment device that uses the relative position and relative attitude measurement device described in the first aspect of the present invention, and is characterized in that it further includes an actuator that adjusts the position or orientation of the object to be measured, and a position angle control unit that controls the actuator so as to approach a predetermined specific position or orientation based on the position or orientation calculated by the position angle deviation calculation unit.

[0019] A relative position and relative attitude adjustment device according to a seventh aspect of the present invention is characterized in that, in the sixth aspect, the position angle deviation calculation unit outputs an error signal that makes the respective phase differences detected by the phase detection units identical, and the position angle control unit controls the actuator based on the error signal output by the position angle deviation calculation unit.

[0020] The relative position and relative attitude adjustment device of the eighth invention is the sixth invention, characterized in that the phase detection unit repeatedly detects each of the phase differences and detects a time-varying value of each of the phase differences, the position angle deviation calculation unit outputs an error signal using the time-varying value of each of the phase differences detected by the phase detection unit as a reference value, and the position angle control unit controls the actuator based on the error signal output by the position angle deviation calculation unit.

[0021] The relative position and relative attitude adjustment system of the 9th invention is a relative position and relative attitude adjustment system using a plurality of the relative position and relative attitude measurement devices of the 1st invention, and is characterized in that it comprises an actuator that controls the direction of the measured object, and a position angle control unit that controls the actuator so that the two or more measured objects perform a predetermined operation based on the position or direction calculated by the position angle deviation calculation unit.

[0022] The antenna direction adjustment system of the tenth aspect of the present invention is an antenna direction adjustment system using the relative position and relative attitude measuring device of the first aspect of the present invention, and is characterized in that it comprises two or more antennas which are the objects to be measured, an actuator which controls the directions of the antennas, and a position angle control unit which controls the actuator so that the two or more antennas face each other based on the position or direction calculated by the position angle deviation calculation unit. Effect of the Invention

[0023] According to the first to tenth inventions, the relative position and relative attitude measurement device calculates the position or direction of the measurement target object on which the propagation phase difference detection antenna is provided, based on the respective phase differences detected by the phase detection unit. As a result, the relative position and relative angle between the two objects can be measured by measuring the phase difference between the two objects over multiple paths. More specifically, it is possible to measure the deviation from the ideal position and the deviation from the ideal angle by using a specific relative position and relative angle as a reference (ideal). Therefore, even when aligning the antennas of a moving body and a fixed station, or between moving bodies, it becomes possible to detect the angle or position deviation that occurs with high real-time accuracy. In the following, when simply referring to a position or angle, unless otherwise specified, it indicates the relative position or relative angle of two or more opposing relative position and relative attitude measurement devices. The relative position here indicates a two-dimensional or three-dimensional relative position (e.g., distances on the X, Y, and Z axes) between the relative position and relative attitude measurement devices, and the relative attitude indicates a relative position between the relative position and relative attitude measurement devices. This represents the two- or three-dimensional relative attitude (e.g., the relative positions of roll, pitch, yaw, and the differences between relative attitude measurement devices) of the satellite.

[0024] Unlike GPS and other systems, which do not indirectly detect the position and angle between two objects via absolute coordinates, this system can directly measure the position and angle relationship between two objects, so in principle the accuracy is doubled even with the same measurement accuracy. This is because indirect measurement requires two measurements, which doubles the error. In addition, because it can measure directly, it can be used in environments where absolute standards such as GPS cannot be used or where accuracy is reduced, such as indoors, under bridges, urban areas with dense skyscrapers, and other places that are not open skies.

[0025] In addition, in the case of angles, the relative angle between objects can be measured without using sensors that know absolute directions, such as geomagnetic sensors that measure directions or acceleration sensors that identify the ground direction associated with gravity. Therefore, it is possible to determine angles with high accuracy by the phase difference of multiple paths, without directly using the outputs of the above-mentioned sensors, which are subject to noise and drift. In addition, unlike other methods such as radar, electrical and mechanical scanning is not required, so measurements can be made at high sampling frequencies, for example, 20 Hz or higher. In addition, if multiple frequency channels are used, multiple detectors can simultaneously measure the phase difference of multiple paths, allowing for faster measurements.

[0026] In particular, according to the second aspect of the present invention, the position angle deviation calculation unit calculates a change in the position or orientation of the object to be measured based on the change in the phase difference detected by the phase detection unit over time, thereby making it possible to calculate the change in the position or angle of the object to be measured in real time.

[0027] In particular, according to the third aspect of the invention, a displacement magnifying mechanism is provided that fixes or supports the object to be measured and increases the distance between the phase difference detection antenna attached to the object to be measured and another phase difference detection antenna, thereby increasing the distance between the phase difference detection antennas, and thus, when detecting an angle deviation based on a phase difference based on radio wave propagation delays over multiple paths, the displacement of the detector accompanying the change in angle can be magnified, making it possible to measure even a slight angle deviation with high accuracy.

[0028] In particular, according to the fourth aspect of the present invention, the propagation phase difference detection unit has a transmitter that can vary the frequency of the transmitted radio waves discretely or continuously. As a result, by using radio waves of a higher frequency, when detecting an angle deviation based on a phase difference based on radio wave propagation delays over multiple paths, the displacement of the detector accompanying this angle change can be magnified, so that even a slight angle deviation can be measured with high accuracy.

[0029] In particular, according to the fifth aspect of the present invention, the position / angle deviation calculation unit calculates the position or angle based on the phase difference and physical information measured by the sensor. As a result, even if the absolute distance of the propagation path cannot be measured due to the phase wrap phenomenon, by using a sensor capable of measuring the approximate position / angle in combination with the sensor, the number of wraps calculated by the unwrapping process using the output of the sensor can be used as an index to measure the position / angle deviation with high accuracy.

[0030] In particular, according to the sixth aspect of the present invention, the position / angle control unit controls the actuator to approach a specific relative position or relative angle set in advance based on the relative position or relative angle calculated by the position / angle deviation calculation unit, thereby enabling the actuator to perform feedback control to correct the detected position / angle deviation, and maintaining the object to be measured in an ideal facing state.

[0031] In particular, according to the seventh aspect of the present invention, the position angle deviation calculation unit outputs an error signal that makes the phase differences detected by the phase detection units equal to each other, and the position angle control unit controls the actuator based on the error signal output by the position angle deviation calculation unit. As a result, even if phase unwrapping is not possible, feedback control is performed so that the change in the phase difference within the range of -π to +π approaches zero, making it possible to correct minute position deviations and angle deviations that may occur with a simple configuration.

[0032] In particular, according to the eighth aspect of the present invention, the position angle deviation calculation unit outputs an error signal that uses the time-varying value of each phase difference detected by the phase detection unit as a reference value, and the position angle control unit controls the actuator based on the error signal output by the position angle deviation calculation unit. This makes it possible to maintain an ideal position and angle by adjusting the object to be measured so that the time-varying value of each phase difference becomes zero.

[0033] In particular, according to the ninth and tenth aspects of the present invention, the position angle control unit controls the actuator so that two or more antennas face each other based on the position or direction calculated by the position angle deviation calculation unit. This allows highly directional antennas such as aperture antennas to be maintained in an ideal facing state, thereby maintaining communication quality. This is a more effective antenna alignment method, particularly when the antennas are mounted on a moving object. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a diagram showing the overall configuration of an antenna direction adjustment system to which a first embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a diagram showing a flowchart of the operation of the antenna direction adjustment system to which the first embodiment of the present invention is applied. [Diagram 3] FIG. 3 is a diagram showing transmission and reception of radio waves between phase difference detection antennas. [Figure 4] FIG. 4 is a diagram showing paths between the respective phase difference detection antennas. [Diagram 5] FIG. 5 is a diagram showing a change that occurs when a translation occurs in the lateral direction. [Figure 6] FIG. 6 is a diagram showing a change that occurs when a translation occurs in the vertical direction. [Figure 7] FIG. 7 is a diagram showing the changes that occur when rotation occurs. [Figure 8] FIG. 8 is a diagram showing a state in which the antenna is tilted by Δθ. [Figure 9] FIG. 9 is a graph showing the minimum detectable angular deviation versus the phase detector installation radius. [Figure 10] FIG. 10 is a diagram showing a moving object facing maintenance system in which the number of phase difference detection antennas installed is 1:3. [Figure 11] FIG. 11 is a diagram showing a moving object facing maintenance system in which the number of phase difference detection antennas installed is three to three. [Figure 12] FIG. 12 is a diagram showing a moving object facing maintenance system in which the number of phase difference detection antennas installed is four to four. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] An antenna direction adjustment system to which a first embodiment of the present invention is applied will be described in detail below.

[0036] Fig. 1 shows the overall configuration of an antenna direction adjustment system 100 to which a first embodiment of the present invention is applied. The antenna direction adjustment system 100 is composed of two or more antenna direction adjustment devices 1 each equipped with an antenna 6, for example, as shown in Fig. 1. The antenna direction adjustment system 100 controls the direction and position of a pair of antennas 6A and 6B each having an aperture, for example, and performs wireless communication using an ultra-high frequency band such as millimeter waves or terahertz waves by arranging the antennas 6A and 6B to face each other.

[0037] The antenna direction adjustment device 1 includes a propagation phase difference detection unit 2, a control unit 3 connected to the propagation phase difference detection unit 2, an actuator 4 connected to the control unit 3, and an antenna 6 connected to the actuator 4 and the propagation phase difference detection unit 2. These components may be connected via wireless communication or the like.

[0038] The propagation phase difference detection unit 2 includes a phase difference detection antenna 5 provided on the antenna 6, a transmitter (TX) 21, a receiver (RX) 22, and a phase detector 23 connected to the phase difference detection antenna 5, and a wireless control unit 24 connected to the transmitter 21, the receiver 22, and the phase detector 23.

[0039] The phase difference detection antenna 5 is provided, for example, on the antenna 6. Two or more phase difference detection antennas 5 may be provided on the antenna 6, for example.

[0040] The transmitter 21 is a transmitter that transmits radio waves via the phase difference detection antenna 5. The transmitter 21 may also be a transmitter that can vary the frequency of the radio waves discretely or continuously. The receiver 22 is a receiver that receives, via the phase difference detection antenna 5, the radio waves transmitted from one or more other propagation phase difference detection units 2.

[0041] The phase detector 23 detects the phase difference between the carrier wave phase at the time of transmission and the carrier wave phase at the time of reception based on the carrier wave phase at the time of transmission of the radio waves at the time of transmission by the transmitter 21 and the carrier wave phase at the time of reception of the radio waves at the time of reception by the receiver 22.

[0042] The wireless control unit 24 outputs control signals to the transmitter 21, the receiver 22, and the phase detector 23. The wireless control unit 24 may also output the phase difference detected by the phase detector 23 to the control unit 3.

[0043] The control unit 3 includes a position angle deviation calculation unit 31 connected to the wireless control unit 24, and an antenna position angle control unit 32 connected to the position angle calculation unit 31. The position angle deviation calculation unit 31 calculates the position or direction of a measurement target object such as the antenna 6 based on each phase difference detected by the phase detector 23. The position angle deviation calculation unit 31 may also acquire physical information from a sensor (not shown) that measures physical information related to the position or direction of the measurement target object such as the antenna 6, or a physical quantity of a first derivative or second derivative of the position or direction, and calculate the position or direction based on the phase difference and the physical information.

[0044] The antenna position angle control unit 32 controls the actuator 4 based on the position or direction calculated by the position angle deviation calculation unit 31 .

[0045] The actuator 4 adjusts the position and direction of the antenna 6 in response to a control signal output from the antenna position angle control unit 32 .

[0046] The antenna 6 is, for example, an aperture antenna. The antenna 6 is provided with a phase difference detection antenna 5, and is a measurement object whose position or direction is calculated by the position angle deviation calculation unit 31. The antenna 6 is not limited to an antenna, and may be any object such as a moving object such as a drone, a robot, or a part thereof. The antenna 6 may be provided on a moving object such as a drone. The measurement object such as the antenna 6 may be provided with any number of phase difference detection antennas 5.

[0047] Furthermore, the antenna 6 may include a displacement magnifying mechanism capable of varying the position of the phase difference detection antenna 5 provided on the antenna 6. The antenna 6 may include a displacement magnifying mechanism capable of increasing the distance between the phase difference detection antenna 5 provided on the antenna 6 and another phase difference detection antenna 5. The antenna 6 may include a displacement magnifying mechanism capable of increasing the distance between, for example, two or more phase difference detection antennas 5A, 5B provided on the antenna 6. Furthermore, the antenna 6 may include a displacement magnifying mechanism that fixes or supports the antenna 6 and is larger in size than the antenna 6.

[0048] Next, a description will be given of the operation of the antenna direction adjustment system 100 to which the first embodiment of the present invention is applied. Fig. 2 is a diagram showing a flowchart of the operation of the antenna direction adjustment system 100 to which the first embodiment of the present invention is applied.

[0049] First, in step S1, the transmitter 21 transmits radio waves via the phase difference detection antenna 5. In step S1, the transmitter 21 may transmit radio waves at regular intervals via the phase difference detection antenna 5. In step S1, the transmitter 21 transmits radio waves at regular intervals via the phase difference detection antenna 5A, for example, as shown in FIG. 3. In addition, the other transmitters 21 may also transmit radio waves via their phase difference detection antennas 5 at approximately the same time.

[0050] Furthermore, in step S1, the antenna 6 may use a displacement magnifying mechanism to place the phase difference detection antenna 5 so as to increase the distance between the phase difference detection antennas 5. For example, the antenna 6 may use a displacement magnifying mechanism to place the phase difference detection antennas 5A and 5B on the displacement magnifying mechanism so as to increase the distance between the phase difference detection antennas 5A and 5B.

[0051] Next, in step S2, phase detector 23 calculates the carrier phase at the time of transmission of the radio wave at the time of transmission in step S1. For example, as shown in Fig. 3, the carrier phase at the time of transmission of the radio wave is calculated via phase difference detection antenna 5A. The carrier phase at the time of transmission is the phase of the carrier of the radio wave at the time of transmission via phase difference detection antenna 5, but is not limited to this, and may be the phase of the carrier of the radio wave at any time.

[0052] Next, in step S3, the phase detector 23 calculates the carrier phase at the time of reception of the radio wave transmitted in step S1 and received via the phase difference detection antenna 5. This radio wave is transmitted via another phase difference detection antenna 5 and received via the phase difference detection antenna 5. Here, the other phase difference detection antenna 5 may be a phase difference detection antenna 5 provided in another antenna direction adjustment device 1. The carrier phase at the time of reception is the phase of the carrier at the time the radio wave is received, but is not limited to this and may be the phase of the carrier of the radio wave at any time. In step S3, for example, the carrier phase at the time of reception is calculated at the time when the radio wave transmitted in step S1 via the phase difference detection antenna 5A and received via the phase difference detection antenna 5C, which is a phase difference detection antenna 5 provided in another antenna direction adjustment device 1, is received. Also, in step S3, for example, the radio waves transmitted through the phase difference detection antenna 5A in step S1 may be received through all the other phase difference detection antennas 5B, 5C, and 5D, respectively, and the carrier phases of the radio waves at the time of reception may be calculated.

[0053] Furthermore, the wireless control unit 24 repeats steps S1 to S3 at regular intervals, and all the propagation phase difference detection units 2 transmit radio waves in turn. After making a round, the wireless control unit 24 repeatedly transmits radio waves. In this case, the wireless control unit 24 transmits radio waves by including its own carrier phase at transmission obtained in the previous step as information. This allows the phase detector 23 to obtain information on both the carrier phase at transmission and the carrier phase at reception.

[0054] The wavelength of the radio wave used by the propagation phase difference detection unit 2 may be, for example, 920 MHz. At 920 MHz, the radio wave can reach a relatively long distance, and as a result, the direction can be adjusted between two antennas 6 that are far apart. In addition, radio waves in the 920 MHz to 5 GHz bands have the characteristic of being radiated isotropically, and even if there is a positional or angular shift, it is possible to obtain a phase difference due to a propagation delay based on the linear distance between the phase difference detection antennas 5, which is the shortest distance that the radio wave can reach. On the other hand, when dealing with radio waves of a higher frequency, the directivity and linearity increase, so that the displacement and rotation detection itself may become impossible to measure due to a positional or angular shift. However, the higher the frequency, the better the distance resolution relative to the phase resolution, so taking these factors into consideration, it is desirable to use a frequency band in the vicinity of 500 MHz to 5 GHz. Furthermore, the distance resolution is expressed as wavelength x phase resolution (°) ÷ 360°.

[0055] Furthermore, when a low frequency band such as the 920 MHz band is used, the sensitivity of the phase detection by the propagation phase difference detection unit 2 is low. For this reason, the propagation phase difference detection unit 2 may adaptively change the frequency used, for example, by using radio waves of 2.4 GHz or 60 GHz in combination. This allows for detection of position and angle deviations with a wide dynamic range and high sensitivity. Alternatively, chirp pulses such as UWB may be used to enable detection of position and angle deviations with higher resolution. In such a case, radio waves of higher frequencies may be handled each time steps S1 to S3 are repeated.

[0056] Furthermore, for example, the antenna 6 may use a displacement magnifying mechanism to position the phase difference detection antennas 5A and 5B so that the distance between the phase difference detection antennas 5A and 5B increases each time steps S1 to S3 are repeated.

[0057] Next, in step S4, the phase detector 23 calculates the phase difference between the carrier phase at the time of transmission and the carrier phase at the time of reception. The carrier phase at the time of reception has a phase difference from the carrier phase at the time of transmission because a propagation delay occurs according to the distance of the path from the phase difference detection antenna 5 that transmitted the radio wave to the phase difference detection antenna 5 that received the radio wave. In addition, the phase difference between the carrier phase at the time of transmission and the carrier phase at the time of reception changes depending on the positional relationship between the antennas 6A and 6B and the change in the angle between the pointing directions of the antennas 6A and 6B.

[0058] The change in the phase difference will be described with reference to FIG. 4. FIG. 4 is a diagram showing the paths between the phase difference detection antennas 5. For example, as shown in FIG. 4, the path from the phase difference detection antenna 5A to the phase difference detection antenna 5C is expressed as v 31 , the path from the phase difference detection antenna 5A to the phase difference detection antenna 5D is v 41 , the path from the phase difference detection antenna 5B to the phase difference detection antenna 5C is v 32 , the path from the phase difference detection antenna 5B to the phase difference detection antenna 5D is v 42 In addition, the phase difference according to the path from the phase difference detection antenna 5A to the phase difference detection antenna 5C is represented as φ 31 , the phase difference according to the path from the phase difference detection antenna 5A to the phase difference detection antenna 5D is φ 41 , the phase difference according to the path from the phase difference detection antenna 5B to the phase difference detection antenna 5C is φ 32 , the phase difference according to the path from the phase difference detection antenna 5B to the phase difference detection antenna 5D is φ 42 In addition, the phase difference φ xy In this notation, x represents the source of the signal and y represents the destination.

[0059] Also, it is assumed here that there is line of sight between antennas 6A and 6B, and that the phase of the direct wave can be measured. In many cases, the aperture antenna itself, which is the object to be measured, is in line of sight, and therefore it is assumed that there is also line of sight between antennas 5 for detecting phase difference, which are similarly installed on antenna 6.

[0060] In step S4, for example, the phase detector 23 detects φ 21 , φ 31 , φ 41 , φ 32 , φ 42 , and φ 43 In this case, the phase detector 23 detects the phase difference φ 31 , φ 41 , φ 32 , φ 42 The phase difference φ 31 , φ 41 , φ 32 , φ 42 is calculated by the difference between the carrier phase at the time of transmission and the carrier phase at the time of reception. In this case, for example, φ 31 is the carrier phase φ of the radio wave at the time of transmission from the phase difference detection antenna 5A. A and the carrier phase φ of the radio wave received by the phase difference detection antenna 5C B Then, φ 31 =φ A -φ B As shown in the figure.

[0061] Also, for example, as shown in Figure 4, v 31 and v 42 are vectors pointing in the same direction, but v 41 and v 32 are vectors pointing in different directions. That is, v 31 or v 42 And, v 41 And, v 32 In an object that has two-dimensional translational degrees of freedom and one-dimensional rotational degrees of freedom, the three vectors have three degrees of freedom. Therefore, it is possible to measure the phase difference in the path of the three degrees of freedom and the distance according to the phase difference.

[0062] Furthermore, in step S4, phase detector 23 may repeatedly detect each phase difference and detect a change in each phase difference over time.

[0063] Next, in step S5, the position angle deviation calculation unit 31 calculates the position or direction of the object to be measured, such as the antenna 6, based on the phase difference calculated in step S4. In step S5, the position angle deviation calculation unit 31 may calculate, for example, a position change between two or more propagation phase difference detection antennas 5 and / or an angle change between the orientation directions of two or more phase difference detection antennas 5. The position change and angle change between the propagation phase difference detection antennas 5 will be described below.

[0064] Fig. 5 is a diagram showing a change when a translation occurs in the horizontal direction, Fig. 6 is a diagram showing a change when a translation occurs in the vertical direction, and Fig. 7 is a diagram showing a change when a rotation occurs.

[0065] As shown in Figure 5, when the object is translated in the horizontal direction a, φ 31 and φ 42 Similarly, φ 41 and φ 32 However, the phase difference value changes while maintaining the relationship, and this can be used to estimate the amount of translation.

[0066] In addition, as shown in FIG. 6, when the object is translated in the vertical direction b, φ 31 and φ 42 While maintaining the same phase difference, φ 41 and φ 32 The phase difference relationship with the phase difference changes. Similarly, the amount of translation can be estimated from these phase differences.

[0067] In addition, as shown in Figure 7, when rotation c occurs, all phase difference relationships are lost, and in particular, the rotation causes φ 31 and φ 42If the installation positions of the phase difference detection antennas 5 installed on the respective antennas 6 are known, the amount of rotation is uniquely determined.

[0068] As described above, the change patterns of each phase difference are different for each of two-dimensional translation and rotation, so it is possible to estimate what kind of displacement and rotation will occur and how much it will be. Although a simple example using phase difference detection antennas 5A, 5B, 5C, and 5D has been given, in practice, it is effective to use an estimation using the least squares method, as in GPS positioning, etc. This allows for a more plausible estimation of the amount of displacement and rotation, taking into account cases where the measured phase difference contains noise. In addition, just as the positioning accuracy improves as the number of GPS captured satellites increases, in order to reduce these measurement noises, phase differences can be obtained in more routes and used to obtain more accurate estimates. As will be described later, a minimum of three pairs, i.e., six phase difference detection antennas 5, are required to estimate the three-dimensional opposing deviations of three-dimensional translation and two-dimensional rotation, but the accuracy can be improved by using more phase difference detection antennas 5 and using the phase differences of multiple routes, so when antenna 6 is a large aperture antenna, etc., it is desirable to install a sufficiently large number of phase difference detection antennas 5.

[0069] In some cases, the detection of parallel movement is not important. For example, in antennas 6A and 6B installed at a distance of several kilometers, a parallel movement of 10 cm is not so important because the beam spreads, but on the other hand, an alignment error between antennas 6A and 6B caused by a rotation or tilt of only 0.1° corresponds to 1.7 m at a distance of 1 km. Therefore, when the beam diameter is less than 1 m, communication between antennas 6A and 6B becomes impossible or communication quality deteriorates. Therefore, in the case of an antenna 6 that is sufficiently fixed, it is more likely that a tilt of 0.1° occurs than a parallel movement of 10 cm, and this degree of parallel movement can be ignored. In such a case, it is also possible to detect only the rotation or tilt on the assumption that no parallel movement occurs, and rotation can be detected with sufficient accuracy even if the number of phase difference detection antennas 5 is small.

[0070] As a simple example, the results of calculating the minimum detectable amount of rotation are shown using Figs. 8 and 9. Fig. 8 is a diagram showing the state in which the antenna 6 is tilted by Δθ. Fig. 9 is a graph showing the minimum detectable angle deviation versus the phase detector installation radius r. The phase detector installation radius r indicates the radius between the phase difference detection antennas 5. Δθ indicates the tilt of the antenna 6. d0 indicates the path distance before the change, and d indicates the path distance after the change. Also, the amount of change in the path before and after the change is Δd.

[0071] Δd can be calculated using equation (1) assuming that Δθ is sufficiently small.

number

[0072] Here, the change Δφ in phase difference caused by Δd is expressed by equation (2).

number

[0073] Here, when using radio waves with a frequency of 920 MHz, the phase difference Δφ min The minimum amount of rotation detection was calculated on the assumption that phase detection can be performed with an accuracy of 1°. The accuracy of rotation detection depends on the installation radius r of the phase detection antenna 5, and the larger the installation radius r, the higher the accuracy. This is because the larger the installation radius r, the greater the displacement of the antenna 6 caused by rotation. If the installation radius r is 1m or more, rotation detection can be performed with an accuracy of less than 0.1°, and the facing deviation between two objects can be detected with better accuracy than orientation estimation using GPS or an inertial measurement unit (IMU).

[0074] The graph in FIG. 9 plots the minimum Δθ at which Δφ=Δφmin, that is, the minimum rotation angle that can be detected, against the radius r of the phase detector installation.

[0075] For this reason, when using the antenna direction adjustment system 100 to which the present invention is applied, it is desirable to arrange the antenna so that the installation radius r is as large as possible. On the other hand, in cases where a high-frequency band antenna 6 or the like is targeted, the antenna 6 itself may be small in size even if it is effectively a large aperture. This is because the size tends to decrease depending on the wavelength even if the aperture area is the same. In such a case, the effect of the antenna direction adjustment system 100 to which the first embodiment of the present invention is applied may not be fully obtained, and it is desirable to provide a displacement magnification mechanism such as a jig / support material (not shown) on the antenna 6. Specifically, it is desirable to prepare a fixing / support jig (not shown) that is larger than the antenna 6 or the object to be measured for displacement / rotation, attach it to the antenna 6, and further install the phase difference detection antenna 5 on this fixing / support jig (not shown). With such a structure, the distance between the phase difference detection antennas 5 becomes large, and minute rotations are magnified, making it possible to detect rotation with sufficient accuracy. In addition, it is desirable to arrange the antennas 6 in an ideal opposing state, and to use a jig shape such that the distance between the phase difference detection antennas 5 is large when viewed from the front. In addition, it is preferable that the material of the support / jig is basically lightweight and does not interfere with the radio waves emitted by the phase difference detection antenna 5, and is preferably, for example, a resin such as plastic, carbon fiber, etc. However, metal materials such as aluminum and stainless steel may be used as long as care is taken with the antenna installation angle so as to suppress the effect on the radiation pattern due to electrical conductivity.

[0076] In step S5, the position angle deviation calculation unit 31 may calculate a change in the position or direction of the object to be measured, such as the antenna 6, based on the time-varying value of each phase difference calculated in step S4. In this case, each phase difference φ AB The propagation time T from when the radio wave is transmitted to when it is received can be calculated from the change in the AB and propagation distance V AB For example, the change in the phase difference φ 31 From the change in value of 31 and propagation distance V 31 The change in the phase difference φ 41 From the change in value of41 and propagation distance V 41 Calculate the change in the propagation time T 31 , T 41 and propagation distance V 31 , V 41 From the change in the position or orientation of the object to be measured, such as the antenna 6, a change in the position or orientation of the object to be measured is calculated. Furthermore, the position or orientation of the object to be measured may include the relative position or relative orientation between two objects to be measured.

[0077] In addition, the propagation time T AB and propagation distance V AB is the phase difference φ AB It can be calculated by the formula (3). Here, T is the time for one period of the radio wave, c is the speed of light. Also, the actual phase difference φ AB Even if the phase difference φ is outside the range of -π to +π, the phase that can be physically observed is in the range of -π to +π. AB and the observed phase difference φ AB Here, the phase difference for one period is the wrap number 1, and N is the phase difference φ AB This indicates the number of wraps of the phase difference φ AB Propagation distance V from AB Since it is possible to calculate the distance between the phase difference detection antennas 5, the distance can be expressed by the phase difference.

number

[0078] Here, by utilizing the fact that the phase changes continuously over time, an unwrapped phase that is not limited to the above-mentioned domain can be obtained by performing an unwrap process. The unwrap process is a process of appropriately selecting N in the following formula to expand the domain of the phase. For example, even if the physically observable phase increases monotonically, it wraps back to -π the moment it exceeds +π. The steep phase change caused by this behavior is used as a trigger to add 2π. As a result, the phase can be handled continuously from +π even after it exceeds +π, so the unwrap process can be performed. Specifically, for example, when a change of π or more occurs, 2π is increased or decreased.

[0079] On the other hand, the unwrapping process is premised on capturing a continuous phase change in time series as described above, and if the antenna 6 experiences a displacement or rotation that causes a steep phase difference outside the range of -π to +π, a relatively large error occurs. For this reason, for example, a method of combining with a relatively low-precision simple distance measurement method is effective. If the frequency of the radio wave being handled is 920 MHz and the phase difference can be detected with an accuracy of 1°, it can be considered to be equivalent to having a distance measurement accuracy of about 1 mm. For this reason, for example, by combining with a distance measurement technology with an accuracy of several tens of cm, a method can be taken in which a rough adjustment is made so that the difference falls within a wavelength of approximately 32 cm, and then fine adjustment is made to the order of 0.1° in step S5. As a result, the coefficient N of the unwrapping is calculated as a rough adjustment, and the phase is used for more accurate measurement, thereby enabling highly accurate position and rotation detection with a simple configuration. Alternatively, as a rough adjustment, the actuator may actually be controlled to adjust the range of the phase difference that occurs to be within the range of -π to +π. As examples of distance measurement technologies or sensors, for example, a gyro sensor that can detect the angular velocity of each moving body, an acceleration sensor that can detect inclination by measuring gravity, a geomagnetic sensor that can detect orientation, etc. can be used in combination to obtain physical information related to position and direction. By installing these sensors, physical information including the direction or position, or the values ​​of the first derivative and second integral of the direction or position can be obtained, so that it becomes possible to estimate more accurate displacement and rotation by combining it with the displacement and rotation estimation based on phase difference of the present invention using a Kalman filter, etc.

[0080] Next, in step S6, the position angle deviation calculation unit 31 outputs an error signal that makes the phase differences calculated in step S4 equal. In this case, the position angle deviation calculation unit 31 may output an error signal that makes the phase differences of the multiple specific paths equal or makes the difference between the phase differences of two specific paths zero, using only the relationship between the phase differences of the multiple specific paths. In this case, for example, 31 , v 42 Phase difference φ 31 , φ 42 Using the relationship, the phase difference φ 31, φ 42 In addition, the error signal that makes two specific paths v 41 , v 32 Phase difference φ 41 , φ 32 The error signal may be output so that the difference between the above is zero.

[0081] Even if unwrapping is not performed in step S5, it is possible to simply maintain the opposing state. As shown in FIG. 31 and φ 42 and have the same phase difference, and φ 41 and φ 32 Since both have the same phase difference, it is possible to bring them into an opposing state by performing feedback control so that the phases of these pairs become the same. That is, φ 31 -φ 42 →0, and φ 41 -φ 32 By controlling the difference to be zero, the opposing state can be maintained. This is the zero method, so the accuracy is improved with simpler processing and methods. Here, we take advantage of the fact that large displacements and rotations that generally exceed the wavelength do not occur.

[0082] Furthermore, in step S6, the position angle control unit 32 may detect the time change value of each phase difference calculated in step S4, and output an error signal that sets the detected time change value of each phase difference to a reference value. In this case, in step S6, the position angle control unit 32 may output an error signal that sets the time change value of each phase difference to zero. This makes it possible to maintain the ideal position and angle.

[0083] Next, in step S7, the antenna position angle control unit 32 controls the actuator 4. For example, the antenna position angle control unit 32 controls the actuator 4 based on the error signal output in step S6. Also, for example, in step S7, the antenna position angle control unit 32 controls the actuator 4 to approach a specific positional relationship or angular relationship set in advance based on the position change and direction change calculated in step S5. In this case, the antenna position angle control unit 32 controls, for example, φ 31 , φ 41 , φ 32 , φ 42 The actuator 4 is controlled so that the difference between the input voltage Vp and the output voltage Vt is a preset constant value or a preset constant difference.

[0084] The above steps complete the operation of the antenna direction adjustment system 100 according to the embodiment of the present invention. As a result, even when aligning antennas between a mobile body and a fixed station, or between mobile bodies, it becomes possible to detect the angle and positional deviation that occurs in more real-time.

[0085] A moving object facing maintenance system to which the second embodiment of the present invention is applied will be described in detail below. The second embodiment differs from the first embodiment in that the object to be measured is a moving object such as a drone.

[0086] Fig. 10 is a diagram showing a moving object facing maintenance system 200 in which the number of phase difference detection antennas 5 installed is 1:3. Fig. 11 is a diagram showing a moving object facing maintenance system 200 in which the number of phase difference detection antennas 5 installed is 3:3. Fig. 12 is a diagram showing a moving object facing maintenance system 200 in which the number of phase difference detection antennas 5 installed is 4:4.

[0087] The mobile object facing maintenance system 200 includes antennas 6A and 6B installed on a mobile object such as a drone (not shown). The antenna 6A includes one phase difference detection antenna 5A1, and the antenna 6B includes three phase difference detection antennas 5B1, 5B2, and 5B3, as shown in FIG. 10. The antenna 6A may include three phase difference detection antennas 5A1, 5A2, and 5A3, and the antenna 6B may include three phase difference detection antennas 5B1, 5B2, and 5B3, as shown in FIG. 11. The antenna 6A may include four phase difference detection antennas 5A1, 5A2, 5A3, and 5A4, and the antenna 6B may include three phase difference detection antennas 5B1, 5B2, 5B3, and 5B4, as shown in FIG. 12.

[0088] As in the first embodiment, the moving body facing maintenance system 200 processes the phase difference detection results, estimates the positional deviation and angular deviation, and then performs aircraft control such as three-dimensional movement and rotation such as roll, pitch, and yaw to approach the facing state.

[0089] As a result, the mobile object facing maintenance system 200 can face the antennas 6 of multiple mobile objects such as drones. In this case, since the actuator is the drone itself, it is possible to utilize the mobility of the drone, which is capable of three-dimensional movement and rotation. Therefore, by doing so, it is possible to face the antennas mounted on the mobile object using only the mobility of the drone. In addition, by controlling the beam more precisely by using not only the mobility of the drone itself but also a highly responsive and precise actuator such as beam forming or a gimbal, it is possible to feedback control the position and angle deviation with high precision with the same high precision.

[0090] The mobile object facing maintenance system 200 may be used not only for mobile objects such as drones, but also for correcting position and rotational deviations that occur due to movement in communication of video data between a television broadcasting van and a broadcasting station. Also, the mobile object facing maintenance system 200 may be used for precisely correcting deviations in the alignment of large aperture antennas such as parabolic antennas installed on the ground, in high gain antennas where slight deviations due to external factors such as wind, rain, and crustal movements are problematic.

[0091] Although the first and second embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. Such novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0092] 1 Antenna direction adjustment device 2. Propagation phase difference detector 3. Control Unit 4 Actuators 5 Phase difference detection antenna 6 Antennas 21 Transmitter 22 Receiver 23 Phase Detector 24 Radio control unit 31 Position and angle deviation calculation unit 32 Antenna position angle control section 100 Antenna Orientation System 200 Mobile Object Opposite Direction Maintenance System

Claims

1. two or more propagation phase difference detection units each having a phase difference detection antenna, a transmitter that transmits radio waves via the phase difference detection antenna, and a receiver that receives radio waves via the phase difference detection antenna; a phase detection unit that detects a phase difference between the carrier phase at the time of transmission and the carrier phase at the time of reception based on a carrier phase at the time of transmission of the radio wave transmitted by the transmitter and a carrier phase at the time of reception of each of the radio waves transmitted from one or more other propagation phase difference detection units and received by the receiver; and a position and angle deviation calculation unit that calculates a position or direction of a measurement object on which the propagation phase difference detection antenna is provided, based on each phase difference detected by the phase detection unit. A relative position and relative orientation measuring device comprising:

2. the phase detection unit repeatedly detects each of the phase differences and detects a change in each of the phase differences over time; The position angle deviation calculation unit calculates a change value of a position or a direction of the object to be measured based on each change value detected by the phase detection unit.

2. The relative position and relative orientation measuring device according to claim 1 .

3. A displacement enlarging mechanism is provided which fixes or supports the object to be measured and increases the distance between the phase difference detection antenna attached to the object to be measured and another phase difference detection antenna.

2. The relative position and relative orientation measuring device according to claim 1,

4. The propagation phase difference detection unit has either a transmitter capable of switching between two or more frequencies of radio waves to be transmitted, or a transmitter capable of varying the frequency of radio waves to be transmitted discretely or continuously.

2. The relative position and relative orientation measuring device according to claim 1 .

5. Further comprising a sensor for measuring physical information relating to a position or a direction of the object to be measured, The position and angle deviation calculation unit calculates the position or the direction based on the phase difference and physical information measured by the sensor.

2. The relative position and relative orientation measuring device according to claim 1 .

6. A relative position and relative attitude adjustment device using the relative position and relative attitude measurement device according to claim 1, An actuator for adjusting a position or a direction of the object to be measured; a position angle control unit that controls the actuator so as to approach a predetermined specific position or direction based on the position or direction calculated by the position angle deviation calculation unit. A relative position and relative attitude adjustment device comprising:

7. the position angle deviation calculation unit outputs an error signal that equalizes the phase differences detected by the phase detection units; The position angle control unit controls the actuator based on the error signal output by the position angle deviation calculation unit.

7. The relative position and relative attitude adjustment device according to claim 6,

8. the phase detection unit repeatedly detects each of the phase differences and detects a change in each of the phase differences over time; the position angle deviation calculation unit outputs an error signal using a time-varying value of each phase difference detected by the phase detection unit as a reference value; The position angle control unit controls the actuator based on the error signal output by the position angle deviation calculation unit.

7. The relative position and relative attitude adjustment device according to claim 6,

9. A relative position and relative attitude adjustment system using a plurality of relative position and relative attitude measurement devices according to claim 1, An actuator for controlling a direction of the object to be measured; a position angle control unit that controls the actuator so that the two or more objects to be measured perform a preset operation based on the position or direction calculated by the position angle deviation calculation unit. A relative position and relative attitude adjustment system comprising:

10. An antenna direction adjustment system using the relative position and relative attitude measurement device according to claim 1, Two or more antennas as the object to be measured; an actuator for controlling the direction of the antenna; a position angle control unit that controls the actuator so that the two or more antennas face each other based on the position or direction calculated by the position angle deviation calculation unit. An antenna orientation system comprising:

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