JPH07167935A - Sonar device for sensing direction - Google Patents

Abstract

PURPOSE:To sense the azimuth of a sound source accurately by forming a sharp split beam adapting to the sound source frequency in the azimuth of the sound source, wherein it is not necessary for generating a number of split beams to cover all azimuths. CONSTITUTION:The phase and frequency of received signals by a pair of receiving elements (for example, 1-1 and 1-2) are sensed by frequency sensing parts 3-1, 3-2, etc., and from them a coarse azimuth sensing part 4-1, etc., determines a coarse azimuth, and a phase alignment control part 5-1, etc., decides a wave receiving element to form a split beam in this azimuth and also defines a phase aligning factor for forming a sharp split beam adapting to the frequency of the received wave, the result wherefrom is passed to a spit beam phase alignment part 7, and there the phase aligning factor is applied to that decoded received signal by the receiving element (s) among the received signals fed from all receiving elements so that a split beam is formed, and only received signal due to this split beam is extracted by a frequency selection part 8, and accurate azimuth is sensed by a fine azimuth sensing part 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passive beam waiting type direction-finding sonar device for detecting the direction of a sound source.

[0002]

2. Description of the Related Art A conventional passive direction-finding sonar device has a large number of pairs of beams with slightly deviated directions, that is, split beams, at a constant angular interval over all directions of 360 ° (for example, 72 at 5 ° intervals). (Split beam, 60 split beams at 6 ° intervals) are provided. The sound source azimuth is obtained from the phase difference between the pair of split beams that captures the sound wave.

FIG. 3 is a block diagram showing the structure of a conventional passive direction-finding sonar device. Reference numeral 1 denotes a wave receiving element, which is arranged in a large number in a circular shape to form a wave receiving portion 2. Now, when one split beam is formed by receiving signals from n receiving elements adjacent to each other, the n receiving signals form one SB phasing unit (split beam phasing unit). ) Sent to 10-k. In FIG. 3, one line connected from the wave receiving unit 2 to each SB phasing unit means n received signals from n adjacent wave receiving elements. In the SB phasing unit, the amplitude and phase of each received signal are controlled by a phasing coefficient that is determined, and a split beam is formed and sent to the target detection unit 11.

Therefore, when m split beams are provided in all directions, m SB phasing units are required. In this case, the split beam angle interval is 360 ° /
m. When the number of receiving elements is N in the entire circumference, 1
The number n of receiving elements forming the split beam of the book is N /
When it is larger than m, the wave receiving element forming one split beam and the wave receiving element forming the adjacent split beam partially overlap with each other. That is, the wave receiving element in the overlapping portion sends the wave receiving signal to both SB phasing units.

For example, in the case where m = 72 split beams are provided in all directions, the number N of receiving elements in the entire circumference is 360.
Then, when one split beam is formed by n = 8 adjacent wave receiving elements, n = 8 is (360/72)
= 5, the three receiving elements contribute to the formation of two adjacent split beams, and two S
The received signal is sent to the B phasing unit.

In this way, m SB phasing units 10-
The split beam output formed by 1 to 10-m is sent to the target detection unit 11. Here, of m split beams, a split beam capturing a sound wave is detected and its output is sent to the azimuth detecting unit 12.

The azimuth detecting section 12 accurately finds which azimuth between the pair beams is the sound source azimuth by using the phase difference or the amplitude difference between the pair of split beams, or by using both of them.

[0008]

However, in the above-described conventional direction-finding sonar device, it is necessary to form a standby split beam in all directions (360 °) in advance in order to detect the direction of the sound source, and the direction accuracy is good. Therefore, a large number of sharp beams must be formed, and the target detection unit also performs detection processing on the outputs of all the beams, resulting in a very large processing load.

Further, since the frequency of the sound source covers a wide range, at a frequency apart from the frequency set for beam forming, the beam width widens or the side lobe becomes stronger due to the frequency characteristics of the beam, which is desirable. However, there is a problem in that the azimuth accuracy deteriorates because the beam characteristics of No.

In view of the above problems of the prior art, an object of the present invention is to maintain a detailed azimuth resolution by forming a beam having a sharp beam width adapted to the frequency of a sound source and to reduce the system processing load. It is to provide a lighter direction-finding sonar device.

[0011]

The present invention has the following means constitution in order to achieve the above object. That is, the direction-finding sonar device of the present invention includes a wave-receiving unit including an array of a plurality of wave-receiving elements for converting a sound wave into an electric signal; It is provided corresponding to each of the two receiving elements that are defined so as to form a pair at an interval of one-half wavelength or less of the upper limit frequency of the band, and the receiving signals of each receiving element are analyzed and received. A frequency detecting section for detecting the frequency and phase of the sound wave; and a sound source direction from the frequency and phase detected by the two frequency detecting sections corresponding to the pair of wave receiving elements and the interval between the wave receiving elements. Rough azimuth detecting section; Determines the receiving element that should use the signal so as to form the split beam in the azimuth calculated by the rough azimuth detecting section, and controls the output amplitude and phase of each receiving element according to the receiving frequency Set the phasing factor and output the phasing factor signal. A control unit; a delay device that delays the output signal of each wave receiving device for a time corresponding to the processing time required by the frequency detecting unit, the rough azimuth detecting unit, and the phasing control unit; and each wave receiving device that passes through the delay unit. And a split beam phasing unit that forms a split beam by controlling the amplitude and phase of the output signal of the wave receiving element determined by the phasing control unit with the phasing coefficient signal; A frequency selecting section for extracting only the frequency component detected by the frequency detecting section from the split beam output of; a fine direction detection for detecting a sound source direction from the amplitude or / and phase of the split beam output of the selectively extracted frequency component A direction-finding sonar device comprising:

[0012]

The operation of the device of the present invention having the above-mentioned means will be described below. The basic principle of the present invention is to divide all detection azimuths (usually 360 °, but not limited to this) into some azimuth range divisions in advance, and to correspond to the division ranges, the receiving element array A pair of two wave receiving elements having an interval equal to or less than the middle half wavelength is defined, and the direction in which the sound wave arrives is first roughly captured from the phase difference between the wave receiving signals received by the two wave receiving elements.

The principle is as follows. When a sound wave of frequency f (wavelength λ) arrives from the direction of the angle θ to the two wave receiving elements A and B provided at a distance d as shown in FIG. 2, the output of the two wave receiving elements Phase difference between
Is expressed by Equation 1.

[0014]

[Equation 1]

Therefore, the sound wave arrival direction θ is expressed by Expression 2 from Expression 1.

[0016]

[Equation 2]

That is, if the phase difference between the received signals of the two wave receiving elements forming a pair, the distance between the wave receiving elements, and the frequency of the sound wave are known, the arrival direction of the sound wave can be known. The distance d between the wave receiving elements is such that the phase difference φ is 0 ° to the sound wave arrival direction θ.
If −180 ° <φ <+ 180 ° with respect to 180 °, the relationship between φ and θ is unique, so it is set to ½ wavelength or less.

Based on the above principle, the outputs of the two wave receiving elements forming a pair are sent to the corresponding frequency detecting sections, where the frequency and phase are detected. The frequency and phase thus obtained are sent to the rough azimuth detecting section, where the phase difference is obtained and the rough azimuth of the sound source is calculated from the phase difference and the frequency and the known distance between the wave receiving elements.

The azimuth information and the frequency information thus obtained are sent to the phasing controller. Based on the azimuth information, the phasing control unit selects and specifies a predetermined number of wave receiving elements for forming a split beam in the azimuth direction from the wave receiving element array. Further, a phasing coefficient signal for controlling the amplitude and phase of each wave receiving element output signal for forming a split beam by the selected wave receiving element is generated by adapting to the frequency of the wave receiving signal.

The receiving element selection designating signal and the phasing coefficient signal thus obtained are sent to the SB phasing unit. Unlike the conventional device, the SB phasing unit is one. On the other hand, the received signals from all the wave receiving elements of the wave receiving unit are input to the SB phasing unit via the delay device. Then, the phasing coefficient signal acts only on the wave receiving signal from the wave receiving element designated by the wave receiving element selection designation signal, and is then combined to form a split beam. The delay device is for delaying each received signal in accordance with the processing time in the frequency detection unit, the rough azimuth detection unit, and the phasing control unit.

While the conventional apparatus always forms a large number of split beams in all directions, the apparatus of the present invention forms a split beam only in the direction roughly detected by the rough direction detection unit. To do.

Since the SB phasing unit outputs a received signal by the split beam and various unnecessary received signals from other receiving elements, the signal of the frequency detected by the frequency detecting unit, that is, the split beam, is output. The output of the SB phasing unit is sent to the frequency selection unit so as to extract only the detected received signal.

The received signal by the split beam thus obtained is sent to the fine azimuth detecting section. The precise azimuth detecting unit itself has the same function as the azimuth detecting unit 12 in the conventional apparatus, and the direction of the sound source is determined by the phase difference or the amplitude difference between the pair of split beams, or both of them. To find out exactly.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the device of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the device of the present invention. N wave-receiving elements are arranged in a circle, and all azimuths are divided by 90 ° into four azimuth range sections. The wave-receiving elements 1-1 and 1-2 form a pair corresponding to each section, and then the wave-receiving elements are paired. The wave elements 1-2 and 1-3 form a pair, and the wave receiving elements 1-3 and 1
-4 forms a pair, and the wave receiving elements 1-4 and 1-1 form a pair.

The received signal of the wave receiving element 1-1 is input to the frequency detecting section 3-1 and the received signal of the wave receiving element 1-2 is input to the frequency detecting section 3-2. Frequency and phase are detected. Hereinafter, the wave receiving elements 1-3 and 1-4
For frequency, the frequencies and phases are detected by the frequency detectors 3-3 and 3-4.

Next, the frequency detectors 3-1 and 3-2
The frequency and the phase detected by 3 are sent to the coarse azimuth detecting section 4-1, and the frequencies and the phases detected by the frequency detecting sections 3-2 and 3-3 are sent to the coarse azimuth detecting section 4-2.
The frequencies and phases detected by the frequency detection units 3-3 and 3-4 are sent to the coarse azimuth detection unit 4-3, and the frequencies and phases detected by the frequency detection units 3-4 and 3-1 are the coarse azimuth detection. It is sent to the section 4-4.

Each rough azimuth detecting section determines the sound source azimuth within the azimuth range divided by the pair of wave receiving elements from the difference and frequency of the two input phase signals and the distance between the pair of wave receiving elements. calculate.

The azimuth information thus obtained and the already obtained frequency information are sent to the phasing control section corresponding to each coarse azimuth detecting section. Based on the input azimuth information, each phasing control unit generates a signal for selecting and specifying a plurality of wave receiving elements for forming a split beam in that azimuth, and forms a split beam by these wave receiving elements. For this purpose, a phasing coefficient signal for controlling the amplitude and phase of each wave receiving element signal is generated by adapting to the frequency of the wave receiving signal.

In this way, the wave receiving element selection designation signal and the phasing coefficient signal generated by each phasing control section are all SB phasing section 7
Sent to. On the other hand, the received signals from all the wave receiving elements of the wave receiving unit 2 are input to the SB phasing unit 7 via the delay devices 6-1 to 6-N. Then, the phasing coefficient signal acts only on the wave receiving signal from the wave receiving element designated by the wave receiving element selection designation signal, and these wave receiving element signals are combined to detect the sound wave within the azimuth division range. A split beam will be formed toward the sound source direction.

During the output of the SB phasing unit 7, in addition to the received signal received by the split beam, various received signals from the receiving elements other than the receiving element forming the split beam are mixed. Therefore, the frequency selection unit 8 extracts only the signal of the frequency detected by the frequency control unit, that is, the received signal by the split beam, and sends it to the precise direction detection unit 9. The fine azimuth detecting unit 9 accurately obtains the sound source azimuth by using the phase difference or the amplitude difference between the two beams forming the split beam, or both of them.

As described above, in the device of the present invention, the sound source azimuth is roughly grasped by the pair of two receiving elements which cover a wide azimuth range in the first step, and the split beam is directed toward the azimuth in the second step. The sound source direction is accurately detected by forming the.

[0032]

As described above, the direction-finding sonar device of the present invention does not have a large number of SB phasing units and a large number of split beams as in the conventional device, but a receiving element. Since the rough azimuth of the sound source is obtained from the received signals of the pair of receiving elements in the row and the split beam is formed in that direction, only one SB phasing unit is required and the scale can be reduced. At the same time, there is an advantage that the processing for detecting the sound source from the received signals of a large number of split beams is unnecessary and the processing load is reduced.

Further, in forming the split beam, since the phasing coefficient is generated in conformity with the frequency of the received signal, the sound source is different from the case where the phasing coefficient is fixed as in the conventional device. There is an advantage that a sharp split beam with few side lobes adapted to the frequency can be formed, and the sound source direction can be detected more accurately than before.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a direction-finding sonar device according to the present invention.

FIG. 2 is a diagram for explaining that the sound source azimuth is obtained from the phase difference between the received signals of the pair of receiving elements.

FIG. 3 is a block diagram showing a configuration example of a conventional direction-finding sonar device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wave receiving element 2 Wave receiving part 3-1 to 3-4 Frequency detecting part 4-1 to 4-4 Rough azimuth detecting part 5-1 to 5-4 Phasing control part 6-1 to 6-N Delay device 7 SB phasing unit 8 Frequency selecting unit 9 Fine direction detecting unit 10-1 to 10-m SB phasing unit 11 Target detecting unit 12 Direction detecting unit

[Procedure amendment]

[Submission date] December 8, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

[0011]

The present invention has the following means constitution in order to achieve the above object. That is, the direction-finding sonar device of the present invention includes a wave-receiving unit including an array of a plurality of wave-receiving elements for converting a sound wave into an electric signal; It is provided corresponding to each of the two receiving elements that are defined so as to form a pair at an interval of one-half wavelength or less of the upper limit frequency of the band, and the receiving signals of each receiving element are analyzed and received. A frequency detecting section for detecting the frequency and phase of the sound wave; and a sound source direction from the frequency and phase detected by the two frequency detecting sections corresponding to the pair of wave receiving elements and the interval between the wave receiving elements. Rough azimuth detecting section; Determines the receiving element that should use the signal so as to form the split beam in the azimuth calculated by the rough azimuth detecting section, and controls the output amplitude and phase of each receiving element according to the receiving frequency Set the phasing factor and output the phasing factor signal. A control unit; of each wave receiving element passing through the delayer; the frequency detector, the coarse direction detecting unit and the only time delay device and causes delays the output signal of the wave receiving element corresponding to the processing time required by the phasing control unit A split beam phasing unit that receives the output signal and controls the amplitude and phase of the output signal of the wave receiving element determined by the phasing control unit by a phasing coefficient signal to form a split beam; A frequency selection unit that extracts only the frequency component detected by the frequency detection unit from the split beam output; and an amplitude of the split beam output of the frequency component that is selectively extracted.
And a phase direction detecting unit for detecting the direction of the sound source from either or both of the phase and the phase ; and a sonar device for direction finding, comprising:

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

During the output of the SB phasing unit 7, in addition to the received signal received by the split beam, various received signals from the receiving elements other than the receiving element forming the split beam are mixed. Since the frequency selection unit 8
Extracting only received signal by the detected frequency of the signal or the split beam by the detecting unit send seminal azimuth detecting unit 9. The fine azimuth detecting unit 9 accurately obtains the sound source azimuth by using the phase difference or the amplitude difference between the two beams forming the split beam, or both of them.

Claims (1)

[Claims] 1. A wave receiving unit comprising an array of a plurality of wave receiving elements for converting a sound wave into an electric signal; and, in the array of the plurality of wave receiving elements, the upper limit frequency of the wave receiving band is divided into two parts for each azimuth section. Is provided corresponding to each of the two receiving elements that are determined to form a pair at intervals of 1 wavelength or less, and the received signal of each receiving element is analyzed to determine the frequency and phase of the received sound wave. A frequency detecting unit for detecting; 2 corresponding to the wave receiving element forming the pair
A rough azimuth detecting section for calculating a sound source azimuth from the frequency and phase detected by one frequency detecting section and the interval between the wave receiving elements;
To determine the receiving element that should use the signal so as to form the split beam in the direction calculated by the rough direction detecting section, set the phasing coefficient that controls the output amplitude and phase of each receiving element according to the receiving frequency. A phasing control unit for outputting a phasing coefficient signal; and a delay device for delaying the output signal of each receiving element by a time corresponding to the processing time required by the frequency detecting unit, the rough azimuth detecting unit and the phasing controlling unit. A split beam alignment that receives the output signal of each receiving element that has passed through the delay device, and controls the amplitude and phase of the output signal of the receiving element determined by the phasing control unit by the phasing coefficient signal to form a split beam. A phase section; a frequency selection section that extracts only the frequency component detected by the frequency detection section from the split beam output from the split beam phasing section; and a split beam of the selectively extracted frequency component A direction detecting sonar device, comprising: a precise direction detecting section that detects a direction of a sound source from the amplitude and / or phase of output.