JP2016223851A - Angle measurement device, rader system, and angle measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angle measurement device capable of accurately estimating the incident angle of a coming radio wave without requiring complicated signal processing.SOLUTION: An angle measurement device 1 includes an antenna (A) 11, antenna (B) 12, and antenna (C) 13 each arranged in one direction. A normalization difference signal generation unit 20 generates a first normalization difference signal by dividing the difference signal between a distribution signal of the antenna (A) 11 and a distribution signal of the antenna (B) 12 by a distribution signal of the antenna (C) 13, and a second normalization difference signal by dividing the difference signal between the distribution signal of the antenna (A) 11 and the distribution signal of the antenna (C) 13 by the distribution signal of the antenna (B) 12. When a radio wave arrival angle cannot be uniquely estimated on the basis of the first normalization difference signal, the radio wave arrival angle is estimated on the basis of the second normalization difference signal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an angle measuring device, a radar device, and an angle measuring method for estimating an angle of arrival of radio waves arriving at a radar.

  A monopulse angle measurement method is known as a method for estimating the arrival angle of a radio wave arriving at a radar with high accuracy. This is to generate the difference signal and sum signal of the output signals of multiple monopulse antennas that receive radio waves, and estimate the arrival angle of radio waves based on the normalized difference signal obtained by dividing the difference signal by the sum signal It is a method to do.

  In this monopulse angle measurement method, the desired arrival wave is affected not only by the direct wave but also by the multi-pulse wave caused by reflection / scattering in the path of arrival, and there is a problem that the estimation accuracy of the arrival angle deteriorates. . In order to solve this problem, a method has been proposed in which degradation of estimation accuracy is suppressed in the process of processing the output signal of the monopulse antenna (for example, Patent Documents 1 and 2).

  The angle measuring device described in Patent Document 1 separates a multipath wave and a direct wave directly using a frequency spectrum of a Σ channel reception signal that is a sum signal of a monopulse antenna and a Δ channel reception signal that is a difference signal. The direction of direct wave arrival is estimated from the wave-only component.

  More specifically, the delay time of each incoming wave is accurately estimated from the frequency spectrum of the Σ channel received signal using a super-resolution algorithm, and a coefficient matrix in which each incoming wave is mixed is estimated. Using the estimated coefficient matrix in common, the components of the desired wave (direct wave) included in the Σ channel and Δ channel are back-estimated to separate and extract. Then, monopulse angle measurement is executed using the directly extracted wave component. For this reason, it is described that the arrival angle of a direct wave can be accurately estimated even when unnecessary interference such as a multipath wave exists.

  In addition, the angle measuring device described in Patent Document 2 prepares an auxiliary antenna different from the monopulse antenna, and estimates the arrival direction of the direct wave from the covariance matrix of the received signal of each antenna using the maximum likelihood estimation method. ing.

  More specifically, a tracking filter for estimating the incident angle of the radio wave based on the maximum likelihood estimation method using the reception signals of the monopulse antenna and the auxiliary antenna and inputting the estimated incident angle is provided. An evaluation function of the maximum likelihood estimation method is calculated in an angle range in the vicinity of the incident angle predicted by the tracking filter, and the incident angle is estimated from an angle at which the evaluation function is maximized. For this reason, it is described that the radio wave incident angle at a low altitude target can be accurately estimated even when there is interference of multipath reflected waves from the sea surface or the ground surface.

JP 2010-286403 A JP 2002-243824 A

  The angle measuring device described in Patent Document 1 performs super-resolution algorithm calculation for separating and extracting components of direct waves, and the angle measuring device described in Patent Document 2 uses received signals of antennas of three or more channels. In order to perform maximum likelihood estimation processing, both require complicated algorithm calculations.

  For this reason, there is a problem that the estimation time becomes long depending on hardware, and the arrival angle cannot be estimated in real time. Further, in order to follow high-speed calculation, there is a problem that the cost is increased because it is necessary to improve hardware and software capabilities.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an angle measuring device or the like that can accurately estimate the incident angle of an incoming radio wave without requiring complicated signal processing. To do.

  In order to achieve the above object, the angle measuring device of the present invention provides a difference signal between the output signals of two or more antennas arranged in a straight line and two antennas selected from the three or more antennas. Based on the standardized difference signal generating unit that outputs two or more standardized difference signals generated by mutually different selections, and the two or more standardized differential signals. And a signal processing unit for estimating a radio wave arrival angle.

  According to the present invention, the radio wave arrival angle is estimated based on two or more standardized difference signals generated from the output signals of different antennas. The incident angle can be estimated with high accuracy.

It is a block diagram of the angle measuring device which concerns on Embodiment 1 of this invention. 2 is an external view of an antenna of the angle measuring device according to Embodiment 1. FIG. 2 is an external view of an antenna of the angle measuring device according to Embodiment 1. FIG. It is a graph which shows the relationship between a standardization difference signal and a radio wave arrival angle. (A) is a graph when only a direct wave is received. (B) is a graph when a multipath wave is included. (C) is a graph showing two normalized difference signals. It is a flowchart of the process which estimates an electromagnetic wave arrival angle. It is a block diagram of the angle measuring device which concerns on Embodiment 2 of this invention. It is a block diagram of the angle measuring device which concerns on Embodiment 3 of this invention. FIG. 6 is an external view of an antenna of an angle measuring device according to a third embodiment. FIG. 6 is an external view of an antenna of an angle measuring device according to Embodiment 3. It is a block diagram of the other example of an angle measuring device. It is a block diagram of the other example of an angle measuring device. It is a flowchart of the process which estimates an electromagnetic wave arrival angle.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described in detail with reference to the drawings.

  The angle measuring device 1 according to the present embodiment is a device that constitutes a part of a radar device and estimates the angle of arrival of radio waves that arrive at the radar device. As shown in FIG. 1, the angle measuring device 1 has an antenna (A) 11, an antenna (B) 12, an antenna (C) 13 that receive radio waves, and a standardized difference signal based on the output signals of the respective antennas. A standardization difference signal generation unit 20 to be generated, and a signal processing unit 50 that performs signal processing for estimating a radio wave arrival angle based on the standardization difference signal.

  The standardized difference signal generation unit 20 synthesizes the signals output from the distributors 21 to 23 and the distributors 21 to 23 that distribute the output signals of the antennas 11 to 13 with a phase difference of 180 degrees. 180 degree hybrid circuits 31 and 32 that output signals, and a division circuit 40 that divides the difference signal output from the 180 degree hybrid circuits 31 and 32 and outputs a normalized difference signal.

  The antenna (A) 11, the antenna (B) 12, and the antenna (C) 13 are arbitrary antennas that convert received radio waves into high-frequency signals and output them, and include a microstrip patch antenna, a dipole antenna, a horn antenna, and the like. Is done.

  These antennas 11 to 13 have the same shape and equivalent conversion efficiency, and are arranged in a straight line as shown in FIGS. FIG. 2 is a diagram showing a case where a microstrip patch antenna is used, and the centers of the receiving areas of the antennas 11 to 13 are arranged in parallel to the y-axis. FIG. 3 is a diagram showing a case where a horn antenna is used, and the centers of the receiving parts at the bottom are arranged in parallel to the y-axis.

The distributors 21 to 23 are arbitrary distributors that output signals having the same phase as each other and having about half the intensity of the input signal. The distributor 21 divides the output of the antenna (A) 11 into two and outputs a distribution signal of output intensity (P _A / 2). The distributor 22 divides the output of the antenna (B) 12 into two and outputs a distribution signal having an output intensity (P _B / 2). The distributor 23 outputs the output of the antenna (C) 13 to 2. Distribute and output a distribution signal of output intensity (P _C / 2).

  The 180-degree hybrid circuits 31 and 32 are arbitrary combining circuits that shift the phase of one of the two input signals by 180 degrees and combine it with the other signal to output a difference signal. It is composed of a rat race hybrid circuit or a waveguide magic T or the like.

The 180-degree hybrid circuit 31 includes a difference signal (P _A / 2-P _B //) between the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal (P _B / 2) output from the distributor 22. 2) is generated and output. The sum signal (P _A / 2 + P _B / 2) is terminated. The 180-degree hybrid circuit 32 includes a difference signal (P _A / 2-P _C /) between the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal (P _C / 2) output from the distributor 23. 2) is generated and output. The sum signal (P _A / 2 + P _C / 2) is terminated.

The division circuit 40 includes difference signals (P _A / 2−P _B / 2) and (P _A / 2−P _C / 2) output from the 180-degree hybrid circuits 31 and 32, and distributors 22 and 23. The output distribution signals (P _B / 2) and (P _C / 2) are input. The division circuit 40 has a function of dividing one input signal by another signal.

The division circuit 40 divides the difference signal (P _A / 2−P _B / 2) by the distribution signal (P _C / 2) to obtain a first normalized difference signal {(P _A −P _B ) / P _C }. The signal {(P _A −P _C ) / P _B } obtained by dividing the difference signal (P _A / 2-P _C / 2) by the distribution signal (P _B / 2) is used as the second normalized difference signal. Output.

The signal processing unit 50 receives the first normalized difference signal {(P _A −P _B ) / P _C } and the second normalized difference signal {(P _A −P _C ) / P _B input from the divider circuit 40. }, The process of estimating the radio wave arrival angle is performed.

  The storage unit built in the signal processing unit 50 includes first data indicating the relationship between the intensity of the first normalized difference signal and the radio wave arrival angle acquired in advance, the intensity of the second normalized difference signal, and the radio wave arrival. Second data indicating a relationship with the corner is stored.

The signal processing unit 50 refers to the first data stored in the storage unit for the first standardized difference signal {(P _A −P _B ) / P _C } acquired during actual operation of the angle measuring device 1, thereby obtaining radio waves. Estimate the angle of arrival. When it is not possible to estimate the single radio wave arrival angle based on the first normalized difference signal, second normalized difference signal obtained during actual operation of the angle measuring device 1 {(P _A -P _C ) / P _B } is referred to the second data stored in the storage unit to estimate the radio wave arrival angle.

  The operation of the angle measuring device 1 configured as described above will be described.

When the radio wave at the angle θ has come to an antenna 11 to 13 arranged as shown in FIG. 2, to the antenna (A) 11, the reception signal of the antenna (B) 12 occurs distance minutes delay of [Delta] d _AB. Accordingly, the standardized difference signal obtained by standardizing the difference signal between the electric signals obtained by converting the radio waves received by the antenna (A) 11 and the antenna (B) 12 changes uniformly with respect to the radio wave arrival angle. Become.

A signal (P _A / 2) obtained by distributing the output signal of the antenna (A) 11 by the distributor 21 and a signal (P _B / 2) obtained by distributing the output signal of the antenna (B) 12 by the distributor 22 are input. The 180-degree hybrid circuit 31 outputs the difference signal (P _A / 2−P _B / 2) to the division circuit 40. The distributor 23 that distributes the output signal of the antenna (C) 13 outputs the signal (P _C / 2) to the divider circuit 40.

The division circuit 40 divides the difference signal (P _A / 2-P _B / 2) by the signal (P _C / 2) to obtain the first normalized difference signal {(P _A −P _B ) / P _C }. . The division circuit 40 outputs the first normalized difference signal {(P _A −P _B ) / P _C } to the signal processing unit 50.

Similarly, the signal received by the antenna (C) 13 is delayed from the antenna (A) 11 by a distance of Δd _AC , so that the radio waves received by the antenna (A) 11 and the antenna (C) 13 are converted. The normalized difference signal obtained by normalizing the difference signal of the electrical signal changes uniformly with respect to the radio wave arrival angle.

A signal (P _A / 2) obtained by distributing the output signal of the antenna (A) 11 by the distributor 21 and a signal (P _C / 2) obtained by distributing the output signal of the antenna (C) 13 by the distributor 23 are input. The 180-degree hybrid circuit 32 outputs the difference signal (P _A / 2−P _C / 2) to the division circuit 40. The distributor 22 that distributes the output signal of the antenna (B) 12 outputs the signal (P _B / 2) to the divider circuit 40.

The division circuit 40 obtains the second normalized difference signal {(P _A −P _C ) / P _B } by dividing the difference signal (P _A / 2−P _C / 2) by the signal (P _B / 2). . The division circuit 40 outputs the second normalized difference signal {(P _A −P _C ) / P _B } to the signal processing unit 50.

  The operation of the signal processing unit 50 to which these normalized difference signals are input will be described using the graph of FIG. 4 and the flowchart shown in FIG.

  When the antennas 11 to 13 detect only a direct wave without being affected by the multipath wave, the intensity of the normalized difference signal input to the signal processing unit 50 is represented by the data series 100 in FIG. As shown, it has a linear characteristic with respect to the radio wave arrival angle. Therefore, by previously acquiring the relationship between the standardized difference signal and the radio wave arrival angle (data series 100), the radio wave arrival angle x1 can be uniquely estimated when the standardized differential signal is v1. .

  On the other hand, when the antennas 11 to 13 are placed in an environment where multipath waves are generated, the normalized difference signal has ripples as shown in the data series 101 of FIG. Will occur. In this case, since the radio wave arrival angle estimated when the normalized difference signal is v1 is a binary value of x1 and x2, the radio wave arrival angle cannot be estimated accurately.

  The signal processing unit 50 according to the present embodiment includes a first normalized difference signal and a second normalized difference signal obtained from three antenna outputs of the antenna (A) 11, the antenna (B) 12, and the antenna (C) 13. Is used to estimate the radio wave arrival angle. Since the first normalized difference signal and the second normalized difference signal are obtained based on the outputs of the antennas having different radio wave reception positions, as shown in the data series 102 and 103 in FIG. The influence of path waves is different from each other.

  That is, when the signal processing unit 50 refers to the first data (data series 102) indicating the relationship between the intensity of the first normalized difference signal and the radio wave arrival angle acquired in advance, the intensity of the first normalized difference signal is v1. When there are two radio wave arrival angles for this, x1 and x2, which cannot be determined uniquely. In that case, using the second data (data series 103) indicating the relationship between the intensity of the second normalized difference signal acquired in advance and the radio wave arrival angle, the intensity of the second normalized difference signal is v2. The radio wave arrival angle is estimated as x1. Therefore, in this case, the signal processing unit 50 outputs a value based on the second normalized difference signal as an estimated value of the radio wave arrival angle.

  Specific processing will be described with reference to the flowchart of FIG. First, the signal processing unit 50 acquires the first normalized difference signal and the second normalized difference signal that are input from the divider circuit 40 during actual operation (step S101). With reference to the first data acquired in advance, it is determined whether there are a plurality of angles corresponding to the acquired first normalized difference signal (step S102).

  If the angle corresponding to the first normalized difference signal is single (step S102: No), the angle based on the first normalized difference signal is output as an estimated value of the radio wave arrival angle (step S103). If there are a plurality of angles corresponding to the first normalized difference signal (step S102: Yes), the angle based on the second normalized difference signal is output as an estimated value of the radio wave arrival angle (step S104).

  In this embodiment, since the antennas are arranged in the y direction, the obtained radio wave arrival angle is an angle on the yz plane in FIG.

  As described above, according to the present embodiment, using the antenna (A) 11, the antenna (B) 12, and the antenna (C) 13 arranged in one direction, the distribution signal of the antenna (A) 11 and the antenna (B) If the radio wave arrival angle cannot be uniquely estimated based on the first normalized difference signal obtained by dividing the difference signal from the distribution signal of 12 by the distribution signal of antenna (C) 13, the antenna (A ) Estimating the radio wave arrival angle based on the second normalized difference signal obtained by dividing the difference signal between the distribution signal of 11 and the distribution signal of antenna (C) 13 by the distribution signal of antenna (B) 12 It was. This makes it possible to estimate the incident angle on one plane of incoming radio waves with high accuracy without requiring complicated signal processing.

Embodiment 2. FIG.
A second embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 6, the angle measuring device 2 according to the present embodiment is based on an antenna (A) 11, an antenna (B) 12, an antenna (C) 13 that receive radio waves, and output signals of the respective antennas. A standardization difference signal generation unit 60 that generates a standardization difference signal, and a signal processing unit 50 that performs signal processing for estimating a radio wave arrival angle based on the standardization difference signal.

  The standardized difference signal generator 60 divides the output signals of the antennas 11 to 13 into two distributors 21 to 23 and a sum signal obtained by synthesizing the signals output from the distributors 21 to 23 with a phase difference of 0 degree. And 180 degree hybrid circuits 31 and 32 that output a difference signal synthesized with a phase difference of 180 degrees, and a difference signal that is output from the 180 degree hybrid circuits 31 and 32 is divided by a sum signal to output a normalized difference signal. Circuit 40.

  The configurations of the antenna (A) 11, the antenna (B) 12, the antenna (C) 13, and the distributors 21 to 23 are the same as those in the first embodiment.

  The 180-degree hybrid circuits 31 and 32 synthesize and output a sum signal without shifting the phase of the two input signals, and the other signal by shifting the phase of one of the two input signals by 180 degrees. And a difference signal is output. The 180-degree hybrid circuits 31 and 32 are arbitrary synthesis circuits, and are composed of, for example, a planar circuit rat race hybrid circuit, a waveguide magic T, or the like.

The 180-degree hybrid circuit 31 has a sum signal (P _A / 2 + P _B / 2) of the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal (P _B / 2) output from the distributor 22. Is generated and output. Further, the 180-degree hybrid circuit 31 has a difference signal (P _A / 2-P) between the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal (P _B / 2) output from the distributor 22. _B / 2) is generated and output. The 180-degree hybrid circuit 32 is a sum signal (P _A / 2 + P _C / 2) of the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal (P _C / 2) output from the distributor 23. Is generated and output. Further, the 180-degree hybrid circuit 32 has a difference signal (P _A / 2−P) between the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal (P _C / 2) output from the distributor 23. _C / 2) is generated and output.

The division circuit 40 includes sum signals (P _A / 2 + P _B / 2) and (P _A / 2 + P _C / 2) output from the 180-degree hybrid circuits 31 and 32, and a difference signal (P _A / 2−P _B / 2) and (P _A / 2-P _C / 2). The division circuit 40 has a function of dividing one input signal by another signal.

The division circuit 40 is obtained by dividing the difference signal (P _A / 2−P _B / 2) by the sum signal (P _A / 2 + P _B / 2) {(P _A −P _B ) / (P _A + P _B )}. Is output as the first normalized difference signal, and the signal {(P _A −P _C ) / () obtained by dividing the difference signal (P _A / 2−P _C / 2) by the sum signal (P _A / 2 + P _C / 2). P _A + P _C )} is output as the second normalized difference signal.

The signal processing unit 50 receives the first normalized difference signal {(P _A −P _B ) / (P _A + P _B )} input from the division circuit 40 and the second normalized difference signal {(P _A −P _C). ) / (P _A + P _C )} is performed to estimate the radio wave arrival angle.

  The storage unit built in the signal processing unit 50 includes first data indicating the relationship between the intensity of the first normalized difference signal and the radio wave arrival angle acquired in advance, the intensity of the second normalized difference signal, and the radio wave arrival. Second data indicating a relationship with the corner is stored.

The signal processing unit 50 refers to the first data stored in the storage unit for the first standardized difference signal {(P _A −P _B ) / (P _A + P _B )} acquired during actual operation of the angle measuring device 2. Thus, the radio wave arrival angle is estimated. When it is not possible to estimate the single radio wave arrival angle based on the first normalized difference signal, second normalized difference signal obtained during actual operation of the angle measuring device 2 {(P _A -P _C ) / (P _A + P _C )} is referred to the second data stored in the storage unit to estimate the radio wave arrival angle.

  The operation of the angle measuring device 2 configured as described above will be described.

When the radio wave at the angle θ has come to an antenna 11 to 13 arranged as shown in FIG. 2, to the antenna (A) 11, the reception signal of the antenna (B) 12 occurs distance minutes delay of [Delta] d _AB. As a result, the normalized difference signal obtained by standardizing the difference signal of the electric signal obtained by converting the radio waves received by the antenna (A) 11 and the antenna (B) 12 with the sum signal has a uniform change with respect to the radio wave arrival angle. Will do.

A signal (P _A / 2) obtained by distributing the output signal of the antenna (A) 11 by the distributor 21 and a signal (P _B / 2) obtained by distributing the output signal of the antenna (B) 12 by the distributor 22 are input. The 180-degree hybrid circuit 31 outputs a sum signal (P _A / 2 + P _B / 2) and a difference signal (P _A / 2−P _B / 2) to the divider circuit 40.

The division circuit 40 divides the difference signal (P _A / 2−P _B / 2) by the sum signal (P _A / 2 + P _B / 2) to obtain the first normalized difference signal {(P _A −P _B ) / ( P _A + P _B )}. The division circuit 40 outputs the first normalized difference signal {(P _A −P _B ) / (P _A + P _B )} to the signal processing unit 50.

Similarly, the signal received by the antenna (C) 13 is delayed from the antenna (A) 11 by a distance of Δd _AC , so that the radio waves received by the antenna (A) 11 and the antenna (C) 13 are converted. The normalized difference signal obtained by normalizing the difference signal of the electrical signal with the sum signal changes uniformly with respect to the radio wave arrival angle.

A signal (P _A / 2) obtained by distributing the output signal of the antenna (A) 11 by the distributor 21 and a signal (P _C / 2) obtained by distributing the output signal of the antenna (C) 13 by the distributor 23 are input. The 180-degree hybrid circuit 32 outputs a sum signal (P _A / 2 + P _C / 2) and a difference signal (P _A / 2-P _C / 2) to the division circuit 40.

The division circuit 40 divides the difference signal (P _A / 2−P _C / 2) by the sum signal (P _A / 2 + P _C / 2), thereby obtaining the second normalized difference signal {(P _A −P _C ) / ( P _A + P _C )}. The division circuit 40 outputs the second normalized difference signal {(P _A −P _C ) / (P _A + P _C )} to the signal processing unit 50.

  The operation of the signal processing unit 50 to which these normalized difference signals are input is the same as in the first embodiment.

  As described above, according to the present embodiment, using the antenna (A) 11, the antenna (B) 12, and the antenna (C) 13 arranged in one direction, the distribution signal of the antenna (A) 11 and the antenna (B) When the radio wave arrival angle cannot be uniquely estimated based on the first normalized difference signal obtained by dividing the difference signal from the distribution signal of 12 by the sum signal, the distribution signal of the antenna (A) 11 The radio wave arrival angle is estimated based on the second normalized difference signal obtained by dividing the difference signal from the distribution signal of the antenna (C) 13 by the sum signal. This makes it possible to estimate the incident angle on one plane of incoming radio waves with high accuracy without requiring complicated signal processing.

Embodiment 3 FIG.
The angle measuring device 3 according to the third embodiment of the present invention is a device that constitutes a part of a radar device and estimates the angle of arrival of radio waves that arrive at the radar device. The angle measuring device 3 includes an antenna (A) 11, an antenna (B) 12, an antenna (C) 13, an antenna (D) 14, and an antenna (E) 15, as shown in FIG. The radio wave arrival angle is estimated based on the outputs of 11 to 15.

  The angle measuring device 3 performs a standardized difference signal generation unit 70 that generates a standardized difference signal based on the output signals of the respective antennas 11 to 15 and a signal process that estimates a radio wave arrival angle based on the standardized difference signal. And a signal processing unit 50 for performing the processing.

  The standardized difference signal generation unit 70 synthesizes the output signals of the antennas 11 to 15 into two distributors 21, 22, 24, 25, and 26 and the signals output from the distributors with a phase difference of 180 degrees. 180 degree hybrid circuits 31 to 34 that output difference signals, and a division circuit 40 that divides the difference signals output from the 180 degree hybrid circuits 31 to 34 and outputs a normalized difference signal.

  The antennas (A to E) 11 to 15 have the same configuration as the antennas (A to C) 11 to 13 of the first embodiment. As shown in FIGS. 8 and 9, the antenna (A) 11, the antenna (B) 12, and the antenna (C) 13 are arranged on the first straight line (y direction). The antenna (C) 13, the antenna (D) 14, and the antenna (E) 15 are arranged on another second straight line (x direction) that intersects the first straight line. That is, in the present embodiment, the angle formed by the first straight line and the second straight line is 90 degrees.

The distributors 21, 22, 25, and 26 are arbitrary distributors that output a signal having the same phase as that of an input signal. Distributor 21 outputs the distribution signal of the antenna (A) 2 distributed to the output intensity of the output _{P A} of 11 _(P A / 2). The distributor 22 distributes the output P _B of the antenna (B) 12 into two and outputs a distribution signal having an output intensity (P _B / 2). Furthermore, distributor 25 outputs the distribution signal of the antenna (D) output _{P D} 2 distributed to the output intensity of 14 _(P D / 2). Furthermore, distributor 26 outputs the distributed signals of the antenna (E) 15 2 distributed to the output intensity of the output _{P E} of the _(P E / 2).

Distributor 24 is any of the distributor which outputs the in-phase signal of one another about one-third of the intensity of the input signal, the antenna (C) 13 3 dispensed output intensity of the output P _C of (P _C / 3) distribution signal is output.

  The 180-degree hybrid circuits 31 to 34 are combined circuits having the same configuration as the 180 hybrid circuits 31 and 32 of the first embodiment.

The 180-degree hybrid circuit 31 has a difference signal (P _A / 2−P _B / 2) between the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal P _B / 2 output from the distributor 22. Is generated and output. The sum signal (P _A / 2 + P _B / 2) is terminated. The 180-degree hybrid circuit 32 has a difference signal (P _A / 2-P _C /) between the distribution signal (P _A / 2) output from the distributor 21 and the distribution signal (P _C / 3) output from the distributor 24. 3) is generated and output. The sum signal (P _A / 2 + P _C / 3) is terminated.

The 180-degree hybrid circuit 33 includes a difference signal (P _E / 2-P _C /) between the distribution signal (P _C / 3) output from the distributor 24 and the distribution signal (P _E / 2) output from the distributor 26. 3) is generated and output. The sum signal (P _E / 2 + P _C / 3) is terminated. The 180-degree hybrid circuit 34 has a difference signal (P _D / 2−P _E /) between the distribution signal (P _D / 2) output from the distributor 25 and the distribution signal (P _E / 2) output from the distributor 26. 2) is generated and output. The sum signal (P _D / 2 + P _E / 2) is terminated.

The division circuit 40 includes difference signals (P _A / 2−P _B / 2), (P _A / 2−P _C / 3), and (P _E / 2−2) output from the 180-degree hybrid circuits 31 to 34, respectively. P _C / 3), (P _D / 2-P _E / 2) and distribution signals P _B / 2, P _C / 2, and P _D / 2 output from the distributors 22, 24, and 25, respectively, are input. The

The division circuit 40 has a function of dividing one signal selected in advance among the input signals by another signal. The division circuit 40 obtains a signal {(3P _A −3P _B ) / 2P _C } obtained by dividing the difference signal (P _A / 2−P _B / 2) by the distribution signal (P _C / 3) as the first normalized difference signal. Output as. Further, a signal {(3P _A −2P _C ) / 3P _B } obtained by dividing the difference signal (P _A / 2−P _C / 3) by the distribution signal (P _B / 2) is output as the second normalized difference signal. .

Further, the division circuit 40 standardizes the signal {(3P _E −2P _C ) / 3P _D } obtained by dividing the difference signal (P _E / 2−P _C / 3) by the distribution signal (P _D / 2). Output as a difference signal. Further, a signal {(3P _D −3P _E ) / 2P _C } obtained by dividing the difference signal (P _D / 2−P _E / 2) by the distribution signal (P _C / 3) is output as the fourth normalized difference signal. .

  The signal processing unit 50 to which these standardized difference signals are input first has a first standardized differential signal obtained from the three antenna outputs of the antenna (A) 11, the antenna (B) 12, and the antenna (C) 13. Based on the second normalized difference signal, the radio wave arrival angle in the yz plane including the first straight line is estimated. Next, xz including the second straight line based on the third normalized difference signal and the fourth normalized difference signal obtained from the three antenna outputs of the antenna (C) 13, the antenna (D) 14, and the antenna (E) 15 Estimate the angle of arrival of radio waves in the plane.

  Then, the radio wave arrival angle in the three-dimensional space is estimated by combining the radio wave arrival angle in the yz plane and the radio wave arrival angle in the xz plane.

  The operation of the angle measuring device 3 configured as described above will be described.

  Radio waves are input at various angles θ to the antennas (A to E) 11 to 15 arranged as shown in FIGS. 8 and 9, and the first to fourth normalized difference signals at that time are acquired in advance. Then, data indicating the relationship between the radio wave arrival angle on the yz plane and the strengths of the first and second normalized difference signals is acquired and stored in the storage unit. Further, data indicating the relationship between the radio wave arrival angle on the xz plane and the intensity of the third and fourth normalized difference signals is acquired and stored in the storage unit.

  In actual operation, first, the signal processing unit 50 acquires the first and second standardized difference signals, refers to the data stored in the storage unit for the acquired signal strength, and arrives at the radio wave on the yz plane. Estimate the angle. The procedure for estimating the radio wave arrival angle is the same as in the first embodiment.

  Similarly, the signal processing unit 50 acquires the third and fourth standardized difference signals, and queries the data stored in the storage unit for the acquired signal strength to estimate the radio wave arrival angle on the xz plane.

  Finally, the signal processing unit 50 outputs an angle obtained by combining the estimated radio wave arrival angle in the yz plane and the radio wave arrival angle in the xz plane as an estimated value of the radio wave arrival angle in the three-dimensional space.

  As described above, according to the present embodiment, the first and second acquired based on the outputs of the antenna (A) 11, the antenna (B) 12, and the antenna (C) 13 arranged on the first straight line. The radio wave arrival angle on one plane is acquired using the normalized difference signal. Further, the third and fourth normalized difference signals acquired based on the outputs of the antenna (C) 13, the antenna (D) 14, and the antenna (E) 15 arranged on the second straight line intersecting the first straight line are used. Thus, the radio wave arrival angle on another plane is acquired. By combining the radio wave arrival angles in these two planes, the radio wave arrival angles in a three-dimensional space were estimated. This makes it possible to estimate the radio wave arrival angle in a three-dimensional space with high accuracy without requiring complicated signal processing.

  In addition, this invention is not limited to the said embodiment, Of course, the various change in the range which does not deviate from the summary of this invention is possible.

For example, in the above embodiment, the first normalized difference signal obtained by dividing the difference signal between the distribution signals of the antenna (A) 11 and the antenna (B) 12 by the distribution signal of the antenna (C) 13, and the antenna (A) The radio wave arrival angle is estimated based on the second normalized difference signal obtained by dividing the difference signal of the distribution signal of 11 and antenna (C) 13 by the distribution signal of antenna (B) 12. A standardized difference signal of a combination of the above may be used. In the case of Embodiment 1, as shown in FIG. 10 or FIG. 11, the difference signal (P _B / 2-P _C / 2) between the distribution signals of the antenna (B) 12 and the antenna (C) 13 is changed to the antenna (A). Other normalized difference signal {(P _B −P _C ) / P _A } obtained by dividing by 11 distribution signals (P _A / 2), and the first normalized difference signal or the second normalized difference signal, , The radio wave arrival angle may be estimated. Also in this case, as in the second embodiment, the estimation may be performed based on the normalized difference signal obtained by dividing the difference signal between the distribution signals of the two antennas by the sum signal.

  Alternatively, four or more standardized difference signals may be acquired using four or more antennas arranged in a straight line, and the radio wave arrival angle may be estimated based on them. In that case, the signal processing unit 50 may execute processing according to the flowchart shown in FIG.

  First, the signal processing unit 50 acquires the first to third normalized difference signals input from the division circuit 40 (step S201). It is determined whether there are a plurality of angles corresponding to the acquired first normalized difference signal by referring to data indicating the relationship between the first normalized difference signal and the angle acquired in advance (step S202). If the angle corresponding to the first normalized difference signal is single (step S202: No), the angle based on the first normalized difference signal is output as an estimated value of the radio wave arrival angle (step S203).

  When there are a plurality of angles corresponding to the first standardized difference signal (step S202: Yes), the second standardized data acquired by referring to the data indicating the relationship between the second standardized differential signal and the angle acquired in advance. It is determined whether there are a plurality of angles corresponding to the difference signal (step S204). When the angle corresponding to the first normalized difference signal is single (step S204: No), the angle based on the second normalized difference signal is output as an estimated value of the radio wave arrival angle (step S205). If there are a plurality of angles corresponding to the second normalized difference signal (step S204: Yes), the angle based on the third normalized difference signal is output as an estimated value of the radio wave arrival angle (step S206).

  By increasing the number of antennas in this way, it is possible to obtain a more accurate estimated value of the radio wave arrival angle. Similarly, when the antennas are arranged on two straight lines intersecting each other as in the third embodiment, the radio wave is generated based on three or more normalized difference signals obtained from the outputs of four or more antennas on the same straight line. The arrival angle may be estimated. At this time, a set of antennas arranged on two straight lines may or may not include the same antenna.

Further, in the third embodiment, the radio wave is generated based on the first normalized difference signal obtained by dividing the difference signal between the distribution signals of the antenna (A) 11 and the antenna (B) 12 by the distribution signal of the antenna (C) 13. While the arrival angle estimated, similarly to the second embodiment, the antenna (a) 11 and the antenna (B) 12 normalized difference signal a difference signal obtained by dividing the sum signal of the distribution signal of {(P _a - P _B ) / (P _A + P _B )} may be used for estimation. Alternatively, the estimation may be performed based on a normalized difference signal obtained by dividing the difference signal of the distribution signals of the antennas 11 to 15 by the sum signal.

  1, 2, 3 Angle measuring device, 11 Antenna (A), 12 Antenna (B), 13 Antenna (C), 14 Antenna (D), 15 Antenna (E), 20, 60, 70 Normalized difference signal generator 21-26 distributor, 31-34 180 degree hybrid circuit, 40 division circuit, 50 signal processing unit, 100-103 data series.

Claims (16)

Three or more antennas arranged in a straight line;
A standardized difference signal obtained by dividing a difference signal of output signals of two antennas selected from the three or more antennas by an output signal of an antenna other than the two antennas is generated by selection different from each other. A standardized difference signal generator for outputting the standardized difference signal;
A signal processing unit that estimates a radio wave arrival angle based on the two or more normalized difference signals;
Angle measuring device comprising: Three or more antennas arranged on the first straight line;
Three or more antennas that are arranged on another second straight line that intersects with the first straight line and that include or do not include one of the three or more antennas arranged on the first straight line. An angle measuring device,
For each of the three or more antennas arranged on the first straight line and the three or more antennas arranged on the second straight line,
A standardized difference signal obtained by dividing a difference signal of output signals of two antennas selected from the three or more antennas by an output signal of an antenna other than the two antennas is generated by selection different from each other. A standardized difference signal generator for outputting the standardized difference signal;
A signal processing unit that estimates a radio wave arrival angle based on the two or more normalized difference signals;
Angle measuring device. The normalized difference signal generator is
A distributor that is connected to each of the three or more antennas and distributes an output of the antenna to output a distribution signal;
A first difference signal output circuit that outputs a first difference signal that is a difference signal of the distributed signals of two antennas selected from the three or more antennas;
A second difference that is a difference signal of the distributed signals of two antennas selected from the three or more antennas, the two antennas being different from at least one antenna selected by the first difference signal output circuit. A second difference signal output circuit for outputting a signal;
A first normalized difference signal obtained by dividing the first difference signal by the distribution signal of an antenna different from the two antennas selected by the first difference signal output circuit, and the second difference signal are converted into the second difference signal. A division circuit that outputs a second normalized difference signal divided by the distribution signal of the antenna different from the two antennas selected by the signal output circuit;
The angle measuring device according to claim 1 or 2. The three or more antennas include a first antenna, a second antenna, and a third antenna arranged at equal intervals from each other,
The first difference signal output circuit outputs the first difference signal of the distribution signal of the first antenna and the second antenna,
The second difference signal output circuit outputs either the first antenna or the second antenna, and the second difference signal of the distribution signal of the third antenna,
The division circuit includes the first normalized difference signal obtained by dividing the first difference signal by the distribution signal of the third antenna, and the second difference signal at the other of the first antenna and the second antenna. Outputting the divided second normalized difference signal;
The angle measuring device according to claim 3. The first difference signal output circuit and the second difference signal output circuit are 180 degree hybrid circuits.
The angle measuring device according to claim 3 or 4. Three or more antennas arranged in a straight line;
A normalized difference signal obtained by dividing the difference signal of the output signals of the two antennas selected from the three or more antennas by the sum signal of the output signals of the two antennas is generated by different selections. A standardized difference signal generator for outputting the standardized difference signal;
A signal processing unit that estimates a radio wave arrival angle based on the two or more normalized difference signals;
Angle measuring device comprising: Three or more antennas arranged on the first straight line;
Three or more antennas that are arranged on another second straight line that intersects with the first straight line and that include or do not include one of the three or more antennas arranged on the first straight line. An angle measuring device,
For each of the three or more antennas arranged on the first straight line and the three or more antennas arranged on the second straight line,
A normalized difference signal obtained by dividing the difference signal of the output signals of the two antennas selected from the three or more antennas by the sum signal of the output signals of the two antennas is generated by different selections. A standardized difference signal generator for outputting the standardized difference signal;
A signal processing unit that estimates a radio wave arrival angle based on the two or more normalized difference signals;
Angle measuring device. The normalized difference signal generator is
A distributor that is connected to each of the three or more antennas and distributes an output of the antenna to output a distribution signal;
A first sum signal that outputs a first difference signal that is a difference signal of the distribution signals of the two antennas selected from the three or more antennas, and a first sum signal that is a sum signal of the distribution signals of the two antennas. A difference signal output circuit;
A difference signal of the distribution signal of two antennas selected from the three or more antennas, wherein the second antenna selected by the first sum / difference signal output circuit is different from at least one antenna. A second sum / difference signal output circuit that outputs a second difference signal and a second sum signal that is a sum signal of the distribution signals of the two antennas;
A division circuit that outputs a first normalized difference signal obtained by dividing the first difference signal by a first sum signal, and a second normalized difference signal obtained by dividing the second difference signal by a second sum signal. ,
The angle measuring device according to claim 6 or 7. The first sum / difference signal output circuit and the second sum / difference signal output circuit are 180-degree hybrid circuits,
The angle measuring device according to claim 8. First data indicating the relationship between the radio wave arrival angle and the intensity of the first normalized difference signal, and the second data indicating the relationship between the radio wave arrival angle and the intensity of the second normalized difference signal, acquired in advance. And a storage unit for storing
When only one radio wave arrival angle corresponding to the first standardized difference signal acquired during actual operation is included in the first data, the signal processing unit outputs the radio wave arrival angle as an estimated value, When two or more are included in the first data, the radio wave arrival angle corresponding to the second normalized difference signal included in the second data is output as an estimated value.
The angle measuring device according to any one of claims 3 to 5, 8, and 9. The three or more antennas are any of a microstrip patch antenna, a dipole antenna, and a horn antenna.
The angle measuring device according to any one of claims 1 to 10.   A radar apparatus comprising the angle measuring device according to any one of claims 1 to 11. An angle measurement method using three or more antennas arranged on a straight line,
A standardized difference signal obtained by dividing a difference signal of output signals of two antennas selected from the three or more antennas by an output signal of an antenna other than the two antennas is generated by selection different from each other. A normalized difference signal generating step for outputting the normalized difference signal;
A signal processing step of estimating a radio wave arrival angle based on the two or more normalized difference signals;
Angular measuring method. Three or more antennas arranged on the first straight line;
Measurement using three or more antennas arranged on another second straight line intersecting with the first straight line and including or not including one of the three or more antennas arranged on the first straight line. Horn method,
For each of the three or more antennas arranged on the first straight line and the three or more antennas arranged on the second straight line,
A standardized difference signal obtained by dividing a difference signal of output signals of two antennas selected from the three or more antennas by an output signal of an antenna other than the two antennas is generated by selection different from each other. A normalized difference signal generating step for outputting the normalized difference signal;
A signal processing step of estimating a radio wave arrival angle based on the two or more normalized difference signals;
Angular measuring method. An angle measurement method using three or more antennas arranged on a straight line,
A normalized difference signal obtained by dividing the difference signal of the output signals of the two antennas selected from the three or more antennas by the sum signal of the output signals of the two antennas is generated by different selections. A normalized difference signal generating step for outputting the normalized difference signal;
A signal processing step of estimating a radio wave arrival angle based on the two or more normalized difference signals;
Angular measuring method. Three or more antennas arranged on the first straight line;
Measurement using three or more antennas arranged on another second straight line intersecting with the first straight line and including or not including one of the three or more antennas arranged on the first straight line. Horn method,
For each of the three or more antennas arranged on the first straight line and the three or more antennas arranged on the second straight line,
A normalized difference signal obtained by dividing the difference signal of the output signals of the two antennas selected from the three or more antennas by the sum signal of the output signals of the two antennas is generated by different selections. A normalized difference signal generating step for outputting the normalized difference signal;
A signal processing step of estimating a radio wave arrival angle based on the two or more normalized difference signals;
Angular measuring method.

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