JP2013205031A - Active sonar device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active sonar device capable of automatically detecting a detection limit distance and displaying a detectable range according thereto.SOLUTION: A control unit 130 for detecting a distance and an azimuth to a target on the basis of a search reception signal of a sonar transducer unit 110 includes: a noise data memory that retains a sonic wave from under water received by the sonar transducer unit 110 as noise data without transmitting the sound wave; and a level comparison computing unit that, when searching a target, compares a level of the search reception signal by the sonar transducer unit 110 with that of the noise data and calculates a point where the level of the search reception signal is same as the level of the noise data, as a detection limit distance. A display unit also displays a detectable range according to the detection limit distance.

Description

  The present invention relates to an active sonar device that calculates and displays a target position by transmitting a sound wave in water and receiving a sound wave reflected by a target in water.

  This type of active sonar device is disclosed in Patent Documents 1 to 4, for example.

  In an active sonar device, in order to improve the search efficiency, it is important to grasp the detectable range. At present, the operator can grasp the detectable range by listening to the sound and finding the detection limit distance sensuously. That is, as shown in FIG. 1, an operator manually captures the listening sound of any single beam channel specified by the cursor on the B scope, and the distance at which the operator can no longer determine the reverberation due to the transmitted sound wave is regarded as the detection limit distance. It was.

JP 2011-002421 A Japanese Patent Laid-Open No. 2001-272459 Japanese Patent Laid-Open No. 11-030661 Japanese Patent Laid-Open No. 10-300841

  However, grasping of the detection limit distance by this listening sound requires an operator to be able to determine whether or not there is reverberation.

  In addition, since the actual underwater environment differs depending on the direction, in order to put it to practical use, it is necessary to grasp the detection limit distance all around. And, in order to grasp the detection limit distance on the entire circumference, the operator needs to perform complicated work of putting the cursor in each direction on the B scope, estimating the detection limit distance by listening sound, and recording the distance. Met.

  Therefore, the subject of this invention is providing the active sonar apparatus which can detect a detection limit distance automatically and can display the detection possible range according to it.

  According to the present invention, a sonar transmission / reception unit that transmits a sound wave in water and receives a sound wave reflected by a target in water, and a distance and direction to the target based on a search reception signal of the sonar transmission / reception unit. And a display unit that graphically displays the distance and azimuth to the target detected by the control unit, the control unit received by the sonar transmission / reception unit without transmitting a sound wave A noise data memory that holds sound waves from underwater as noise data, and a search reception signal by the sonar transmission / reception unit at the time of target search is compared in level with noise data, and the level of the search reception signal and noise data is the same And a level comparison calculator that calculates the detection limit distance, and the display unit responds to the detection limit distance calculated by the level comparison calculation unit in addition to the distance and direction to the target. Active sonar apparatus is obtained and displaying also detectable ranges.

  It further includes a beam phasing unit that circularly scans the transmitted / received sound waves of the sonar transmitting / receiving unit, and the noise data memory does not transmit sound waves but receives all sound waves from the water received by the sonar transmitting / receiving unit as noise data. The level comparison computing unit compares the level of the search reception signal by the sonar transmission / reception unit with the noise data at the time of target search, and detects the point where the level of the search reception signal and the noise data is the same as the detection limit distance. May be calculated for all directions.

  The control unit includes a search reception signal memory for holding a search reception signal by the sonar transmission / reception unit during target search, and a noise from the search reception signal memory when the signal from the sonar transmission / reception unit is a search reception signal. In the case of data, the noise data memory may further include a memory switch for switching a data holding destination.

  The display unit may display a distance to a target and a direction in a B scope format.

  The level comparison computing unit compares the level of the search reception signal by the sonar transmission / reception unit with the noise data and echo during target search, and calculates a range where the search reception signal is greater than or equal to the noise data and less than or equal to the echo as a detectable range. The display unit may display the detectable range calculated by the level comparison calculation unit in addition to the distance and direction to the target.

  The active sonar device according to the present invention can automatically detect a detection limit distance and display a detectable range corresponding to the detection limit distance.

It is a figure which shows the example of a display on B scope of the active sonar apparatus by related technology. It is a figure for demonstrating operation | movement of the active sonar apparatus by this invention, and is a figure which shows the level of the reverberation according to distance. It is a block diagram which shows the structure of the active sonar apparatus by Example 1 of this invention. It is a figure which shows the example of a display on B scope of the active sonar apparatus by Example 1 of this invention. It is a figure for demonstrating operation | movement of the active sonar apparatus by Example 1 of this invention, and is a figure which shows the level of underwater noise. It is a flowchart for demonstrating operation | movement of the level comparison calculator in the active sonar apparatus by Example 1 of this invention. It is a figure for demonstrating operation | movement of the active sonar apparatus by Example 1 of this invention, and is a figure which shows the level of the reverberation according to distance, and the level of the underwater noise. It is a figure for demonstrating operation | movement of the active sonar apparatus by Example 2 of this invention, and is a figure which shows the level of an echo. It is a figure for demonstrating operation | movement of the active sonar apparatus by Example 2 of this invention, and is a figure which shows the level of the reverberation according to distance, and the level of echo. It is a figure which shows the example of a display on B scope of the active sonar apparatus by Example 2 of this invention.

  An active sonar device according to the present invention transmits a sound wave in water and receives a sound wave reflected by a target in water, and a distance and direction to the target based on a search reception signal of the sonar wave transmission / reception part. And a display unit that graphically displays the distance and direction to the target detected by the control unit.

  In particular, in the present active sonar apparatus, the control unit includes a noise data memory that holds, as noise data, sound waves from the water received by the sonar transmission / reception unit without transmitting sound waves, and search reception by the sonar transmission / reception unit during target search. A level comparison calculator that compares the level of the signal with noise data and calculates a point where the level of the received search signal and the noise data is the same as a detection limit distance is provided.

  The display unit displays a detectable range corresponding to the detection limit distance calculated by the level comparison calculation unit in addition to the distance and direction to the target.

  Here, as shown in FIG. 2, the level of the detection signal (search reception signal) after the active sonar device actively transmits is reduced when the influence of reverberation decreases as the distance increases. It becomes the same as the noise level. The distance at which the reverberation level and the noise level are the same is set as the detection limit distance, and this processing is performed in the beam channel of the entire circumference. By drawing and connecting the distances obtained from this on the B scope, as shown in FIG. 4, the detectable range with the detection limit line taking into account the difference in propagation status for each direction as a boundary is extended over the entire circumference. Can be represented visually.

  With this configuration, the active sonar device can automatically detect the detection limit distance and display a detectable range corresponding to the detection limit distance. More specifically, this active sonar device has the following effects.

  The first effect is that the detection limit distance of the active sonar can be easily known without being a skilled operator. The reason is that, unlike the conventional method in which the operator manually obtains the listening sound and determines the distance, the range in which the reverberation cannot be heard is automatically read and drawn.

  The second effect is that drawing can be performed in all directions in consideration of the difference in environmental conditions for each direction. The reason for this is that, unlike the conventional method in which the detection limit distance obtained by a single beam listening sound is grasped, detection limit points are simultaneously extracted from beams in all directions.

  The third effect is that it is possible to provide a material for determining the target and the erroneous target for the bright spot displayed on the B scope. The reason for this is that it is unlikely that active transmission reverberation is obtained from a distance farther than the detection limit line indicated by the present invention, and it can be determined that the displayed target is likely to be a false target. is there.

  The fourth effect is that information for recommending the movement of the ship to maintain the target is provided. The reason is that, since the range in which the reverberation sound cannot be obtained is known, it is possible to make a proposal for moving the ship so that the target does not enter the range.

  The fifth effect is that it can be used as a judgment material for efficient search range selection. The reason is that it is possible to determine that it is not necessary to perform active transmission up to the range because the range in which no reverberation sound can be obtained is known.

  Hereinafter, a more specific embodiment of the active sonar apparatus according to the present invention will be described with reference to the drawings.

  Referring to FIG. 3, the active sonar apparatus 10 according to the first embodiment of the present invention includes a sonar transmission / reception unit 110, a beam phasing unit 120, a control unit 130, and a display unit 140.

  The sonar transmitting / receiving unit 110 transmits sound waves in water and receives sound waves reflected by the target in water. The beam phasing unit 120 scans the transmitted and received sound waves of the sonar transmission / reception unit 110 in a circular manner.

  The control unit 130 detects the distance to the target and the direction based on the search reception signal of the sonar transmission / reception unit 110. The display unit 140 graphically displays the distance to the target and the direction detected by the control unit 130 in a B scope format. The control unit 130 includes a memory switch 131, a search reception signal memory 132, a noise data memory 133, and a level comparison calculator 134.

  The memory switch 131 switches the data holding destination to the search reception signal memory 132 when the signal from the sonar transmission / reception unit 110 is a search reception signal, and to the noise data memory 133 when the signal is noise data.

  The search reception signal memory 132 holds a search reception signal from the sonar transmission / reception unit 110 during target search.

  The noise data memory 133 holds sound waves from the water received by the sonar transmission / reception unit 110 without transmitting sound waves as noise data.

  The level comparison calculator 134 compares the level of the search reception signal by the sonar transmission / reception unit 110 with noise data during target search, and calculates a point where the level of the search reception signal and noise data is the same as the detection limit distance.

  The display unit 140 displays a detectable range corresponding to the detection limit distance calculated by the level comparison calculator 134 in addition to the distance and direction to the target.

  Next, the operation of the active sonar device will be described.

  First, in a state where active transmission is not performed, that is, without transmitting a sound wave from the sonar transmission / reception unit 110, the beam is phased and received by the beam phasing unit 120 via the sonar transmission / reception unit 110. The received noise is output to the noise data memory 133 under the control of the memory switch 131, and stored as averaged noise level data as shown in FIG. At this time, the search reception signal by the sonar transmission / reception unit 110 is controlled by the memory switch 131 so as to be output to the noise data memory 133. In other words, only noise information that does not include a reverberant component is extracted and stored.

  Next, during target search, active transmission, that is, sound waves are transmitted from the sonar transmission / reception unit 110. At this time, the beam search reception signal in the active sonar is in a state where reverberation and noise due to transmission are mixed. The search reception signal is output and stored in the search reception signal memory under the control of the memory switch 131. At this time, the search reception signal by the sonar transmission / reception unit 110 is controlled by the memory switch 131 so as to be output to the search reception signal memory 132.

  Next, the operation of the level comparison calculator will be further described with reference to the flowchart of FIG.

  The level comparison operator 134 acquires the search reception signal data held in the search reception signal memory 132 in the previous procedure (step S10), and compares the level of the noise data held in the noise data memory 133 in the same procedure. (Steps S20 and S30).

  That is, the level comparison is performed between the search reception signal (reverberation) and the noise level data. As shown in FIG. 7, if the compared levels are the same, it is assumed that reverberation has disappeared, that is, it is difficult to distinguish the reverberant sound, and the distance at that time is calculated as a detection limit distance, and is displayed on the display unit 140. The data is output (step S40). The detection limit distance is calculated using data for all directions.

  As shown in FIG. 4, the display unit 140 draws a line connecting the detection limit distances of the beams in each direction on the B scope. In the illustrated example, the lower side of the detection limit distance line represents the detectable range.

  The second embodiment of the present invention is different from the first embodiment in that the method for obtaining the detectable range is based on the echo level in addition to the detection limit distance. For this reason, about the part which is the same as that of Example 1, or the same part, the description and reference drawing in Example 1 will be used, and detailed description is abbreviate | omitted.

  By the way, the active sonar device can capture a reverberant sound when the echo level exceeds the reverberation level. The echo level is affected by the propagation loss in the sea, and generally becomes smaller in inverse proportion to the distance as shown in FIG.

  When this is applied to the present invention, a detectable range can be set as shown in FIG. In FIG. 9, the right end of the detectable range in the figure is the detection limit distance calculated by the same processing as in the first embodiment.

  When this is drawn on the B scope, a more detailed detectable range can be displayed as shown in FIG.

  Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the technical scope described in the claims.

DESCRIPTION OF SYMBOLS 110 Sonar transmission / reception part 120 Beam phasing part 131 Memory switch 130 Control part 132 Search reception signal memory 133 Noise data memory 134 Level comparison arithmetic unit 140 Display part

Claims (5)

A sonar transmission / reception unit that transmits sound waves underwater and receives sound waves reflected by a target underwater;
Based on the search reception signal of the sonar transmission / reception unit, a control unit for detecting the distance and direction to the target;
A display unit that graphically displays the distance and direction to the target detected by the control unit;
The controller is
A noise data memory for holding sound waves from the water received by the sonar transmission / reception unit without transmitting sound waves as noise data;
A level comparison computing unit that compares the level of the search reception signal by the sonar transmission / reception unit at the time of target search with noise data and calculates the point where the level of the search reception signal and noise data is the same as the detection limit distance,
In addition to the distance and direction to the target, the display unit displays a detectable range corresponding to the detection limit distance calculated by the level comparison calculation unit. A beam phasing unit that scans the transmitted and received sound waves of the sonar transmitting and receiving unit;
The noise data memory retains sound waves from underwater received by the sonar transmitting / receiving unit without transmitting sound waves for all directions as noise data,
The level comparison computing unit compares the level of the search reception signal by the sonar transmission / reception unit with the noise data during target search, and calculates the point where the level of the search reception signal and the noise data is the same as the detection limit distance for all directions. The active sonar device according to claim 1.   The control unit includes a search reception signal memory for holding a search reception signal by the sonar transmission / reception unit during target search, and a noise from the search reception signal memory when the signal from the sonar transmission / reception unit is a search reception signal. The active sonar device according to claim 1, further comprising a memory switch for switching a data holding destination in the noise data memory when data is used.   4. The active sonar device according to claim 1, wherein the display unit displays a distance to a target and an orientation in a B scope format. 5. The level comparison computing unit compares the level of the search reception signal by the sonar transmission / reception unit with the noise data and echo during target search, and calculates a range where the search reception signal is greater than or equal to the noise data and less than or equal to the echo as a detectable range. ,
The active sonar apparatus according to claim 1, wherein the display unit displays a detectable range calculated by the level comparison calculation unit in addition to a distance and a direction to a target.

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