JP2015021855A - Target detection device, target detection method, program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a target detection device that enables a target to be surely detected without a wrong detection of noise as the target even when a target length of the target is short.SOLUTION: A target detection device 100 has: a transmission/reception part 110 that transmits a transmission wave, and receives a reflection wave of the transmission wave to be reflected from a target 200; a distance calculation part 122 that calculates first and second distances which are respective distances from the transmission/reception part 110 to one end part of the target 200 and the other end part thereof; an azimuth change rate generation part 124 that generates azimuth change rate information which is information indicative of a relation between a distance from the transmission/reception part 110 and an azimuth change rate, which is a change rate per unit distance of an arrival azimuth,; and a target determination part 130 that determines whether the target 200 is the detection target on the basis of the first and second distances and the azimuth change rate information.

Description

  The present invention relates to a target detection device and the like, for example, a target detection device that detects a target in water.

  In recent years, radars, sonars, and the like are widely known as devices that transmit radio waves, sound waves, and the like and detect a target using a reflected wave from the target.

  In relation to the above, Patent Document 1 discloses that in a sonar, two reception beams (hereinafter referred to as split beams) having equal reception directivities with respect to an arbitrary direction are formed, and two split beams on the left and right sides are formed. A technique is described in which the phase difference of the reflected wave from the target is obtained by performing a correlation operation on the output, and the target is detected from the phase error variance that is the variance on the time axis of the obtained phase difference.

  Patent Document 2 describes a sonar technique for detecting a target using a feature element such as an amplitude calculated based on a reflected wave in addition to the above-described phase error dispersion.

JP 59-072073 A JP-A-11-052046

  However, in the technique using the phase error dispersion exemplified in Patent Document 1 and Patent Document 2 described above, when the target length of the target is short, there is not a sufficient reflected wave signal length to converge the phase error dispersion. However, there is a problem that the target error is erroneously detected because it is indistinguishable from the phase error variance when noise is received. On the sea surface, the target length of the target detected by the sonar changes depending on the relative angle between the target to be detected and the sonar, and the echo length also changes according to the target length. Therefore, there is a problem that it is difficult to determine an optimum dispersion processing section in which the phase error dispersion value converges when receiving the reflected wave from the target object, and the detection accuracy is lowered.

  The present invention has been made in view of such circumstances, and an object of the present invention is to reliably detect noise as a target object even when the target length of the target object is short, for example. It is another object of the present invention to provide a target detection apparatus capable of detecting a target.

  The target object detection apparatus of the present invention includes a transmission / reception unit that transmits a transmission wave and receives a reflection wave of the transmission wave reflected from the target, a distance from the transmission / reception unit, and a signal S / N ratio of the reflection wave Based on signal S / N (Signal / Noise) ratio information which is information indicating the relationship between the first and second distances from the transmission / reception unit to one end and the other end of the target A distance calculation unit that calculates a distance, and a unit distance between the distance from the transmission / reception unit and the arrival direction based on arrival direction information that is information indicating a relationship between the distance from the transmission / reception unit and the arrival direction of the reflected wave An azimuth change rate generating unit that generates azimuth change rate information that is information indicating a relationship with an azimuth change rate that is a winning change rate, and the first distance and the second distance calculated by the distance calculation unit And before being generated by the direction change rate generation unit On the basis of the azimuth rate of change information, the target is; and a target determining unit that determines whether or not the detected target.

  In the target detection method of the present invention, the transmission / reception unit transmits a transmission wave and receives the reflected wave of the transmission wave reflected from the target, the distance from the transmission / reception unit, and the signal of the reflected wave Based on signal S / N ratio information which is information indicating a relationship with the S / N ratio, first and second distances which are respective distances from the transmitting / receiving unit to one end and the other end of the target Per unit distance between the distance from the transceiver and the arrival direction based on the arrival direction information which is information indicating the relationship between the distance from the transceiver and the arrival direction of the reflected wave. An azimuth change rate generating step for generating azimuth change rate information, which is information indicating a relationship with an azimuth change rate that is a change rate of the first, and the first distance and the second distance calculated by the distance calculating step; The direction change rate student Based on said azimuth rate of change information generated by the step, the target comprises a target determination step of determining whether or not the detection target.

  The program of the present invention is a transmission / reception step in which a transmission / reception unit transmits a transmission wave to a computer and receives a reflection wave of the transmission wave reflected from a target, a distance from the transmission / reception unit, and a signal of the reflection wave Based on signal S / N ratio information which is information indicating a relationship with the S / N ratio, first and second distances which are respective distances from the transmitting / receiving unit to one end and the other end of the target Per unit distance between the distance from the transceiver and the arrival direction based on the arrival direction information which is information indicating the relationship between the distance from the transceiver and the arrival direction of the reflected wave. An azimuth change rate generating step for generating azimuth change rate information, which is information indicating a relationship with an azimuth change rate that is a change rate of the first, and the first distance and the second distance calculated by the distance calculating step; The above Wherein based on the azimuth rate of change information generated by the position change rate generating step, the target is to execute, and the target determination step of determining whether or not the detection target.

  According to the target object detection apparatus of the present invention, a target object can be reliably detected without erroneously detecting noise as a target object.

It is a block diagram which shows the structure of the target detection apparatus in embodiment of this invention. It is a figure which shows the positional relationship of the transmission / reception part and target object of the target object detection apparatus in embodiment of this invention. It is a figure which shows the operation | movement flow of the target object detection apparatus in embodiment of this invention. It is a figure showing an example of the signal S / N ratio information which shows the relationship between the distance from the transmission / reception part of the target object detection apparatus and signal S / N ratio in embodiment of this invention. It is a figure showing an example of the signal S / N ratio information which shows the relationship between the distance from the transmission / reception part of the target object detection apparatus and signal S / N ratio in embodiment of this invention. It is a figure showing an example of the arrival direction information which shows the relationship between the distance from the transmission / reception part of the target object detection apparatus in embodiment of this invention, and the arrival direction of a reflected wave. It is a figure showing an example of the direction change rate information which shows the relationship between the distance from the transmission / reception part of the target object detection apparatus in embodiment of this invention, and direction change rate. It is a figure showing an example of the direction change rate information which shows the relationship between the distance from the transmission / reception part of the target object detection apparatus in embodiment of this invention, and direction change rate.

  A detailed configuration of the target object detection apparatus 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a target object detection apparatus 100 according to an embodiment of the present invention.

  As illustrated in FIG. 1, the target detection apparatus 100 includes a transmission / reception unit 110, a control unit 120, a target determination unit 130, and a display unit 140.

  As shown in FIG. 1, the transmission / reception unit 110 is connected to the control unit 120. The transmission / reception unit 110 transmits a transmission wave such as a radio wave or a sound wave, and receives a reflection wave of the transmission wave reflected from the target 200. In addition, the transmission / reception unit 110 simultaneously receives a signal such as noise in addition to the reflected wave signal reflected from the target 200. Hereinafter, signals such as reflected waves and noise are collectively referred to as reception signals. The transmission / reception unit 110 outputs the received signal to the control unit 120. The transmission / reception unit 110 also outputs to the control unit 120 the time when the transmission wave is transmitted, the time when the reception signal is received, and the direction in which the reception signal is incident on the transmission / reception unit 110.

  The transmission / reception unit 110 is a transmission / reception device that transmits radio waves such as sonar and radar, transmission waves such as sound waves and light waves, and receives reflected waves of a target. However, the transmission / reception unit 110 is not limited to a sonar or a radar. Here, an example in which the transmission / reception unit 110 is an active sonar is shown. However, the transmission / reception unit 110 is not necessarily an active sonar and may be a radar or the like as described above.

  As shown in FIG. 1, the control unit 120 is connected to the transmission / reception unit 110, the target object determination unit 130, and the display unit 140. The control unit 120 controls the entire target detection device 100. The control unit 120 includes a signal S / N ratio generation unit 121, a distance calculation unit 122, an arrival direction generation unit 123, and a direction change rate generation unit 124. In addition, the control unit 120 acquires a reception signal received by the transmission / reception unit 110. In addition, the control unit 120 outputs the calculation result of the distance calculation unit 122 and the generation result of the azimuth change rate generation unit 124 to the target object determination unit 130. The control unit 120 also outputs various results output from the signal S / N ratio generation unit 121, the distance calculation unit 122, the arrival direction generation unit 123, and the direction change rate generation unit 124, and the determination result of the target determination unit 130. Is output to the display unit 140.

  As shown in FIG. 1, the signal S / N ratio generation unit 121 is included in the control unit 120. The signal S / N ratio generation unit 121 is a signal S / N that is information indicating the relationship between the distance from the transmission / reception unit 110 to the generation source of each reception signal and the signal S / N ratio [dB] of each reception signal. Generate ratio information. Specifically, the signal S / N ratio generation unit 121 performs a known correlation process such as a replica correlation process on the reception signal including the reflected wave signal received by the transmission / reception unit 110, to thereby generate a signal. S / N ratio information is generated. The replica correlation processing performed by the signal S / N ratio generation unit 121 is, for example, a reception wave including a signal that is a sample of a transmission wave signal transmitted by the transmission / reception unit 110 and a reflected wave signal received by the transmission / reception unit 110. This is a process for calculating the degree of correlation with the received signal. This replica correlation processing is also called cross-correlation processing. The specific processing content of the signal S / N ratio generation unit 121 will be described in detail in the description of the operation flow described later.

  As shown in FIG. 1, the distance calculation unit 122 is included in the control unit 120. Based on the signal S / N ratio information generated by the signal S / N ratio generation unit 121, the distance calculation unit 122 is the respective distance from the transmission / reception unit 110 to one end and the other end of the target 200. First and second distances are calculated. As described above, the calculation result calculated by the distance calculation unit 122 is output to the target object determination unit 130 by the control unit 120. The specific processing content of the distance calculation unit 122 will be described in detail in the description of the operation flow described later.

  As shown in FIG. 1, the arrival direction generation unit 123 is included in the control unit 120. The arrival direction generation unit 123 generates arrival direction information that is information indicating the relationship between the distance from the transmission / reception unit 110 to the generation source of each reception signal and the arrival direction of each reception signal. The specific processing contents of the arrival direction generating unit 123 will be described in detail in the description of the operation flow described later.

  As shown in FIG. 1, the azimuth change rate generation unit 124 is included in the control unit 120. Based on the arrival direction information generated by the arrival direction generation unit 123, the direction change rate generation unit 124 per unit distance of the distance from the transmission / reception unit 110 to the generation source of each reception signal and the arrival direction of each reception signal Direction change rate information, which is information indicating the relationship with the direction change rate that is the change rate of. As described above, the generation result generated by the direction change rate generation unit 124 is output to the target determination unit 130 by the control unit 120. The specific processing content of the azimuth change rate generation unit 124 will be described in detail in the description of the operation flow described later.

  As shown in FIG. 1, the target determination unit 130 is connected to the control unit 120. In addition, the target object determination unit 130 uses the first distance and the second distance calculated by the distance calculation unit 122 and the direction change rate information generated by the direction change rate generation unit 124 to use the target 200. It is determined whether or not is a detection target. As described above, the determination result of the target 200 determined by the target determination unit 130 is output to the display unit 140 by the control unit 120. The specific processing contents of the target object determination unit 130 will be described in detail in the description of the operation flow described later.

  As shown in FIG. 1, the display unit 140 is connected to the control unit 120. The display unit 140 displays and displays various results of the signal S / N ratio generation unit 121, the distance calculation unit 122, the arrival direction generation unit 123, and the direction change rate generation unit 124, and the determination result of the target object determination unit 130. Thereby, the operator can visually confirm the distance from the transmission / reception unit 110 to the target 200, its orientation, and whether the target 200 is a detection target.

  Here, the positional relationship between the transmission / reception unit 110 and the target 200 will be described with reference to FIG. FIG. 2 is a diagram illustrating a positional relationship between the transmission / reception unit 110 of the target object detection apparatus 100 and the target object 200 according to the embodiment of the present invention. As shown in FIG. 2, it is assumed that the transmission / reception unit 110 and the target 200 are arranged in the positional relationship shown in FIG. Further, the distance from the transmission / reception unit 110 to one end of the target 200 is r1, and the distance from the transmission / reception unit 110 to the other end of the target 200 is r2. As shown in FIG. 2, it is assumed that one end and the other end of the target 200 are both on the same line OL passing through the center of the transmission / reception unit 110. One end of the target 200 is a point where the straight line OL and the outer periphery of the target 200 first intersect, and the other end of the target 200 is next to the straight OL and the outer periphery of the target 200. Intersect points. That is, one end and the other end of the target 200 correspond to both ends of the straight line OL that overlap the target 200, respectively.

  Further, the direction in which the received signal is incident on the transmission / reception unit 110 with respect to the reference direction (north direction in the figure) is defined as the arrival direction. As shown in FIG. 2, the arrival direction of the reflected wave reflected from the target 200 is θ. Here, the reference direction is the direction that matches the north direction passing through the center of the transmission / reception unit 110, but is not limited thereto.

  Next, the operation of the target detection apparatus 100 in the embodiment of the present invention will be described in detail with reference to FIG. FIG. 3 is a diagram showing an operation flow of the target object detection apparatus 100 according to the embodiment of the present invention.

  First, as shown in FIG. 3, the transmission / reception unit 110 transmits a transmission wave and receives a reception signal including a reflected wave signal reflected from the target 200 (step (hereinafter referred to as S) 110). . The transmission / reception unit 110 outputs the received signal to the control unit 120.

  Next, as shown in FIG. 3, the signal S / N ratio generation unit 121 generates signal S / N ratio information based on the reception signal input by the transmission / reception unit 110 (S120). The signal S / N ratio generation unit 121 outputs the signal S / N ratio information to the distance calculation unit 122. Then, the distance calculation unit 122 is based on the signal S / N ratio information generated by the signal S / N ratio generation unit 121 and the respective distances from the transmission / reception unit 110 to one end and the other end of the target 200. A certain first distance r1 and second distance r2 are calculated (S121). The distance calculation unit 122 outputs the calculation result to the target object determination unit 130.

  Here, more detailed processing of S120 and S121 will be described with reference to FIGS.

  First, the process of S120 will be described in detail with reference to FIG. FIG. 4 is a diagram illustrating an example of signal S / N ratio information indicating the relationship between the distance from the transmission / reception unit 110 of the target object detection apparatus 100 and the signal S / N ratio according to the embodiment of the present invention. Specifically, FIG. 4 shows a distance 4800 [yd (yard)] to 5100 [yd] from the transmission / reception unit 110 to the generation source of each reception signal including a reflected wave signal and the signal S / of each reception signal. The relationship of N ratio is shown. In FIG. 4, the signal S / N ratio [dB] is set on the vertical axis, and the distance [yd] from the transmission / reception unit 110 is set on the horizontal axis.

  As shown in FIG. 4, the signal S / N ratio generation unit 121 performs correlation processing such as replica correlation processing on the received signal including the signal of the reflected wave from the target 200 received in S110, Signal S / N ratio information, which is information indicating the relationship between the distance from the transmission / reception unit 110 to the source of each received signal and the signal S / N ratio of each received signal, is generated. Note that the signal S / N ratio information illustrated in FIG. 4 is an example for explaining the present embodiment, and the distance from the transmission / reception unit 110 to the generation source of each reception signal is 4800 [yd]. It is not limited to ˜5100 [yd]. Further, the value of each signal S / N ratio with respect to the distance from the transmission / reception unit 110 to the generation source of each reception signal is not limited to the value shown in FIG.

  Next, the process of S121 will be described in detail with reference to FIGS. FIG. 5 is a diagram illustrating an example of signal S / N ratio information indicating the relationship between the distance from the transmission / reception unit 110 of the target object detection apparatus 100 and the signal S / N ratio in the embodiment of the present invention. FIG. 5 is an enlarged view of a portion corresponding to a distance 4900 [yd] to 4950 [yd] from the transmission / reception unit 110 in FIG.

  First, the distance calculation unit 122 acquires the signal S / N ratio information generated by the signal S / N ratio generation unit 121 illustrated in FIGS. Next, as shown in FIGS. 4 and 5, the distance calculation unit 122 sets the distance from the transmission / reception unit 110 at which the signal S / N ratio is equal to or greater than a predetermined threshold value (here, 6 dB) as a first value. Calculated as distance r1. In the example of FIGS. 4 and 5, the first distance r1 = 4924 [yd].

  Then, as shown in FIGS. 4 and 5, the distance calculation unit 122 calculates a distance from the transmission / reception unit 110 that is larger than the first distance r1 and for which the signal S / N ratio is below the threshold value for the first time as the second distance r2. To do. In the example of FIGS. 4 and 5, the second distance r2 = 4926 [yd].

  As described above, an example in which the predetermined threshold is 6 dB is shown here. However, the predetermined threshold is not limited to 6 dB, and is set to an arbitrary value in consideration of the signal detection sensitivity of the signal S / N ratio and the like.

  Here, a case where there is one target 200 is illustrated. However, the target object 200 may be plural. When there are a plurality of targets 200, the distance calculation unit 122 is a distance from the transmission / reception unit 110 that is equal to or greater than a predetermined threshold with respect to the signal S / N ratio information at a distance from the transmission / reception unit 110 that is greater than the second distance r2. And the process of calculating the distance from the transmission / reception unit 110 which is larger than the calculated distance from the transmission / reception unit 110 and whose signal S / N ratio falls below the threshold for the first time is repeated. Thereby, even if there are a plurality of targets 200, the distance calculation unit 122 can calculate the respective distances from the transmission / reception unit 110 to one end and the other end of each target.

  Returning to FIG. 3, the arrival direction generation unit 123 generates arrival direction information based on the reception signal input by the transmission / reception unit 110 and the arrival direction of the reception signal (S <b> 130). The arrival direction generation unit 123 outputs the arrival direction information to the direction change rate generation unit 124. Then, the direction change rate generation unit 124 generates direction change rate information indicating the relationship between the distance from the transmission / reception unit 110 and the direction change rate based on the arrival direction information generated by the arrival direction generation unit 123 (S131). ). The direction change rate generation unit 124 outputs the direction change rate information to the target object determination unit 130. Detailed processing of S130 and S131 will be described later. Here, an example is shown in which the processing of S130 and S131 is performed after the processing of S120 and S121. However, all the processes of S120, S121, S130, and S131 need only be performed before the process of S140. For example, the processes of S120 and S121 may be performed after the processes of S130 and S131. Further, the processes of S130 and S131 may be performed simultaneously with the processes of S120 and S121.

  Here, the processing of S130 and S131 will be described in detail with reference to FIGS.

  First, the process of S130 will be described with reference to FIG. FIG. 6 is a diagram illustrating an example of arrival direction information indicating the relationship between the distance from the transmission / reception unit 110 of the target object detection apparatus 100 and the arrival direction of the reflected wave according to the embodiment of the present invention. Specifically, FIG. 6 illustrates the distances 4800 [yd] to 5100 [yd] from the transmission / reception unit 110 to the generation source of each reception signal including the reflected wave signal, and the arrival direction [deg (degree] of each reception signal. )] Relationship. In FIG. 6, the arrival direction [deg] is set on the vertical axis, and the distance [yd] from the transmission / reception unit 110 is set on the horizontal axis.

  As shown in FIG. 6, the arrival azimuth generation unit 123 generates each reception azimuth of each reception signal including the reflected wave signal from the target 200 received in S <b> 110 and the generation source of each reception signal from the transmission / reception unit 110. The arrival direction information indicating the relationship with the distance between is generated. Note that the arrival direction information illustrated in FIG. 6 is an example for explaining the present embodiment, and the distance from the transmission / reception unit 110 to the generation source of each reception signal is 4800 [yd] to 5100 [ It is not limited to yd]. Further, the value of the arrival direction with respect to the distance from the transmission / reception unit 110 to the generation source of each received signal is not limited to the value shown in FIG.

  Next, the process of S131 will be described with reference to FIGS. First, the direction change rate generation unit 124 acquires arrival direction information exemplified in FIG. 6 from the arrival direction generation unit 123. Next, the azimuth change rate generation unit 124 calculates each azimuth change rate in the distance from the transmission / reception unit 110 to the source of each received signal, based on the arrival direction information illustrated in FIG. Specifically, the azimuth change rate generation unit 124 determines the arrival azimuth of the received signal at a distance r from the transmission / reception unit 110 and the arrival azimuth of the reception signal at a distance r + Δr (Δr: distance resolution) from the transmission / reception unit 110. By dividing the difference value by Δr, an azimuth change rate [deg / yd] that is a change rate per unit distance of the incoming azimuth at the distance r + Δr from the transmission / reception unit 110 is calculated.

  That is, the direction change rate DiffData [r + Δr] at the distance r + Δr from the transmission / reception unit 110 is expressed by the following equation (1).

DiffData [r + Δr] = (Direction [r + Δr] −Direction [r]) / Δr (1)
Direction: Arrival Direction An example of the direction change rate information generated by the direction change rate generation unit 124 as described above is shown in FIG. FIG. 7 is a diagram illustrating an example of azimuth change rate information indicating the relationship between the distance from the transmission / reception unit 110 of the target object detection apparatus 100 and the azimuth change rate according to the embodiment of the present invention. Specifically, FIG. 7 shows the relationship between the distance 4800 [yd] to 5100 [yd] from the transmission / reception unit 110 to the generation source of the reception signal including the reflected wave signal and the direction change rate. In FIG. 7, the azimuth change rate [deg / yd] is set on the vertical axis, and the distance [yd] from the transmission / reception unit 110 is set on the horizontal axis. Note that the azimuth change rate information illustrated in FIG. 7 is an example for explaining the present embodiment, and the distance from the transmission / reception unit 110 is not limited to 4800 [yd] to 5100 [yd]. Further, the value of the direction change rate with respect to the distance from the transmission / reception unit 110 is not limited to the value shown in FIG.

  Returning to FIG. 3, finally, the target determining unit 130 includes the first distance r <b> 1 and the second distance r <b> 2 calculated by the distance calculating unit 122, and the direction change rate generated by the direction change rate generating unit 124. Using the information, it is determined whether or not the target 200 is a detection target (S140).

  Here, the process of S140 will be described in detail with reference to FIG. FIG. 8 is a diagram illustrating an example of azimuth change rate information indicating the relationship between the distance from the transmission / reception unit 110 of the target object detection apparatus 100 and the azimuth change rate according to the embodiment of the present invention. FIG. 8 is an enlarged view of a portion corresponding to the distance 4900 [yd] to 4950 [yd] from the transmission / reception unit 110 in FIG. 7.

  First, the target determination unit 130 acquires the first distance r1 and the second distance r2 from the distance calculation unit 122, and acquires the direction change rate information illustrated in FIGS. 7 and 8 from the direction change rate generation unit 124. To do.

  Next, as shown in FIG. 8, the target object determination unit 130 has a direction change rate from the first distance r1 to the second distance r2 within a predetermined range (here, ± 0 as a predetermined threshold). .05 [deg / yd]). When the azimuth change rate from the first distance r1 to the second distance r2 is within a predetermined range, the target object determination unit 130 determines that the target object 200 is a detection target. This is because noise and the like are generated in all directions, and the arrival direction at a distance from the transmission / reception unit 110 is not continuous, and the direction change rate increases. On the other hand, for example, as shown in FIG. 2, the arrival azimuth at a distance from one end portion to the other end portion of the target 200 is continuous, and the azimuth change rate becomes small. Therefore, the target object determination unit 130 can determine that the target object 200 is a detection target when the azimuth change rate from the first distance r1 to the second distance r2 is within a predetermined range.

  In addition, when the azimuth change rate from the first distance r1 to the second distance r2 is not within the predetermined range, the target determination unit 130 determines that the target 200 is not a detection target.

  That is, the target object determination unit 130 determines that the target object 200 is a detection target when the following expression (2) is satisfied.

Under the condition of r1 ≦ r ≦ r2,
DiffData [r1] ≦ Threshold, DiffData [r1 + Δr] ≦ Threshold ≦… DiffData [r2] ≦ ThreShold (2)
ThreShold: predetermined threshold (here, ± 0.05 [deg / yd])
Here, an example in which the threshold value is ± 0.05 [deg / yd] is shown as being within a predetermined range in which the target object determination unit 130 determines whether or not the target object 200 is a detection target. However, the threshold value is not limited to the above value, and is set to an arbitrary value according to the direction change rate information generated by the direction change rate generation unit 124, for example. Even if there are a plurality of targets 200, the target determination unit 130 may calculate the distances from the transmission / reception unit 110 calculated by the distance calculation unit 122 to one end and the other end of each target, Based on the direction change rate information, it can be determined whether or not each target is a detection target.

  As described above, the target detection apparatus 100 according to the embodiment of the present invention includes the transmission / reception unit 110, the distance calculation unit 122, the azimuth change rate generation unit 124, and the target determination unit 130. Yes. The transmission / reception unit 110 transmits a transmission wave and receives a reflection wave of the transmission wave reflected from the target 200. The distance calculation unit 122 is connected to one end of the target 200 from the transmission / reception unit 110 based on the signal S / N ratio information, which is information indicating the relationship between the distance from the transmission / reception unit 110 and the signal S / N ratio of the reflected wave. First and second distances that are respective distances to the other end are calculated. The azimuth change rate generation unit 124 changes the distance from the transmission / reception unit 110 and the arrival azimuth per unit distance based on arrival direction information which is information indicating the relationship between the distance from the transmission / reception unit 110 and the arrival direction of the reflected wave. Direction change rate information that is information indicating a relationship with the direction change rate that is a rate is generated. The target object determination unit 130 detects the target object 200 based on the first distance and the second distance calculated by the distance calculation unit 122 and the direction change rate information generated by the direction change rate generation unit 124. It is determined whether it is a target.

  As described above, the target object detection apparatus 100 according to the embodiment of the present invention determines whether or not the target object 200 is a detection target using the first and second distances and the direction change rate information. For this reason, unlike the techniques described in Patent Documents 1 and 2, the target is not detected using phase error dispersion. The target object detection device 100 looks at the azimuth change rate from the first distance r1 to the second distance r2, and when the azimuth change rate is within a predetermined range, the target object detection device 100 performs the second change from the first distance r1 to the second distance r2. When the target 200 is detected between the distances r2 and the direction change rate is outside the predetermined range, it is determined as noise or the like. Therefore, it is clarified whether the target 200 is a detection target or noise. Further, the target object detection apparatus 100 detects the target object 200 without depending on the signal length of the reflected wave. Therefore, even if the target length of the target 200 is short, the target 200 can be reliably detected without erroneously detecting noise as the target 200.

  In the target object detection apparatus 100 according to the embodiment of the present invention, the distance calculation unit 122 calculates the distance from the transmission / reception unit 110 at which the signal S / N ratio is equal to or greater than a predetermined threshold as the first distance, The distance from the transmission / reception unit 110 that is greater than the distance of 1 and for which the signal S / N ratio is below the threshold for the first time is calculated as the second distance. Thereby, the 1st and 2nd distance which is each distance from the transmission / reception part 110 to the one end part and the other end part of the target 200 can be calculated more correctly.

  In the target object detection apparatus 100 according to the embodiment of the present invention, the azimuth change rate generation unit 124 has an arrival direction at a distance r from the transmission / reception unit 110 and a distance r + Δr (Δr: distance resolution) from the transmission / reception unit 110. By dividing the difference value from the arrival direction by Δr, the direction change rate information at the distance r + Δr from the transmission / reception unit 110 is calculated, thereby generating the direction change rate information. Thereby, the azimuth | direction change rate for every distance resolution (DELTA) r can be calculated, and the detection accuracy of the target 200 can be improved more.

  The target object detection method according to the embodiment of the present invention includes a transmission / reception step, a distance calculation step, an azimuth change rate calculation step, and a target determination step. In the transmission / reception step, the transmission / reception unit 110 transmits a transmission wave and receives a reflection wave of the transmission wave reflected from the target 200. In the distance calculation step, one end portion of the target 200 and the like from the transmission / reception unit 110 based on the signal S / N ratio information, which is information indicating the relationship between the distance from the transmission / reception unit 110 and the signal S / N ratio of the reflected wave First and second distances that are respective distances to the end are calculated. The azimuth change rate calculating step is based on arrival direction information that is a relationship between the distance from the transmission / reception unit 110 and the arrival direction of the reflected wave, and the rate of change per unit distance between the distance from the transmission / reception unit 110 and the arrival direction. The direction change rate information that is information indicating the relationship with the direction change rate is generated. In the target determination step, whether or not the target 200 is a detection target based on the first distance and the second distance calculated in the distance calculation step and the direction change rate information generated in the direction change rate generation step. Determine whether. Since this target object detection method is based on the invention of the target object detection apparatus 100 described above, the same effect as the target object detection apparatus 100 described above can be obtained.

  In addition, the program according to the embodiment of the present invention causes a computer to execute a transmission / reception step, a distance calculation step, an orientation change rate calculation step, and a target object determination step. In the transmission / reception step, the transmission / reception unit 110 transmits a transmission wave and receives a reflection wave of the transmission wave reflected from the target 200. In the distance calculation step, one end portion of the target 200 and the like from the transmission / reception unit 110 based on the signal S / N ratio information, which is information indicating the relationship between the distance from the transmission / reception unit 110 and the signal S / N ratio of the reflected wave First and second distances that are respective distances to the end are calculated. The azimuth change rate calculating step is based on arrival direction information that is a relationship between the distance from the transmission / reception unit 110 and the arrival direction of the reflected wave, and the rate of change per unit distance between the distance from the transmission / reception unit 110 and the arrival direction. The direction change rate information that is information indicating the relationship with the direction change rate is generated. In the target determination step, whether or not the target 200 is a detection target based on the first distance and the second distance calculated in the distance calculation step and the direction change rate information generated in the direction change rate generation step. Determine whether. Since this program is an invention of the program of the device detection apparatus 100 described above, the same effects as the above-described target detection apparatus 100 can be obtained.

  The present invention has been described above based on the embodiments. The embodiment is an exemplification, and various changes, increases / decreases, and combinations may be added to the above-described embodiment without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 100 Target object detection apparatus 110 Transmission / reception part 120 Control part 121 Signal S / N ratio generation part 122 Distance calculation part 123 Arrival direction generation part 124 Direction change rate generation part 130 Target object determination part 140 Display part 200 Target object

Claims (7)

A transmission / reception unit for transmitting a transmission wave and receiving a reflected wave of the transmission wave reflected from a target;
Based on signal S / N ratio information, which is information indicating a relationship between the distance from the transmission / reception unit and the signal S / N ratio of the reflected wave, from the transmission / reception unit to one end and the other end of the target. A distance calculator that calculates the first and second distances, which are the respective distances;
Based on arrival direction information which is information indicating the relationship between the distance from the transmission / reception unit and the arrival direction of the reflected wave, the direction change rate which is the change rate per unit distance between the distance from the transmission / reception unit and the arrival direction An azimuth change rate generating unit that generates azimuth change rate information that is information indicating the relationship between
Whether the target is a detection target based on the first distance and the second distance calculated by the distance calculation unit and the direction change rate information generated by the direction change rate generation unit And a target object determination unit for determining the target object. The distance calculation unit calculates a distance from the transmission / reception unit at which the signal S / N ratio is equal to or greater than a predetermined threshold as the first distance;
The target detection apparatus according to claim 1, wherein a distance from the transmission / reception unit that is larger than the first distance and the signal S / N ratio is lower than the threshold value for the first time is calculated as the second distance.   The direction change rate generation unit divides a difference value between the arrival direction at a distance r from the transmission / reception unit and the arrival direction at a distance r + Δr (Δr: distance resolution) from the transmission / reception unit by Δr. The target detection apparatus according to claim 1, wherein the direction change rate information is generated by calculating the direction change rate at a distance r + Δr from the transmission / reception unit.   The target object determination unit determines whether the target object is a detection target based on whether the direction change rate from the first distance to the second distance is within a predetermined range. The target object detection apparatus according to any one of claims 1 to 3. A transmission / reception unit that transmits a transmission wave and receives a reflected wave of the transmission wave reflected from a target; and
Based on signal S / N ratio information, which is information indicating a relationship between the distance from the transmission / reception unit and the signal S / N ratio of the reflected wave, from the transmission / reception unit to one end and the other end of the target. A distance calculating step for calculating a first distance and a second distance that are respective distances;
Based on arrival direction information which is information indicating the relationship between the distance from the transmission / reception unit and the arrival direction of the reflected wave, the direction change rate which is the change rate per unit distance between the distance from the transmission / reception unit and the arrival direction Direction change rate generation step for generating direction change rate information that is information indicating the relationship between
Whether or not the target is a detection target based on the first distance and the second distance calculated by the distance calculation step and the direction change rate information generated by the direction change rate generation step. A target determination step for determining the target. On the computer,
A transmission / reception unit that transmits a transmission wave and receives a reflected wave of the transmission wave reflected from a target; and
Based on signal S / N ratio information, which is information indicating a relationship between the distance from the transmission / reception unit and the signal S / N ratio of the reflected wave, from the transmission / reception unit to one end and the other end of the target. A distance calculating step for calculating a first distance and a second distance that are respective distances;
Based on arrival direction information which is information indicating the relationship between the distance from the transmission / reception unit and the arrival direction of the reflected wave, the direction change rate which is the change rate per unit distance between the distance from the transmission / reception unit and the arrival direction Direction change rate generation step for generating direction change rate information that is information indicating the relationship between
Whether or not the target is a detection target based on the first distance and the second distance calculated by the distance calculation step and the direction change rate information generated by the direction change rate generation step. And a target object determining step for determining the program.   A computer-readable recording medium on which the program according to claim 6 is recorded.

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