DE102007046803A1 - Sonar device for finding direction of acoustic sources in water, has time delay device that is downstream to transducer elements, in which time delay is adjustable for delaying time of electrical output signal of transducer elements - Google Patents

Abstract

The device has an acoustic underwater antenna with multiplicity of electroacoustic transducers (15) arranged in an antenna insertion position. A time delay device (18) is downstream to transducer elements (13), in which a time delay is adjustable for delaying a time of an electrical output signal of the transducer elements. The time delay is determined by a desired vertical adjustment of a main sound receipt direction of the antenna. A position of the transducer element is determined based on adjustment. A set of transducer-element-specific delay is identical with all transducers.

Description

The The invention relates to a sonar device according to the preamble of Claim 1.

A known sonar device for locating sound sources located in the water ( EP 1 176 428 B1 ) has a planar extended underwater antenna, a so-called. Surface antenna or a surface array, in which a plurality of spaced apart transducer elements in rows and columns are arranged on a support. In the antenna insert position, the rows run approximately horizontally and the columns at right angles to it. The mutually arranged in the columns transducer elements form an electro-acoustic transducer, also called Stave, which has a directional characteristic with a much smaller vertical opening angle than a transducer element. This is achieved by adding the output signals from all the transducer elements arranged in a column to one another and outputting the averaged sum signal as the output signal or the received signal of the converter. Due to the reduced vertical opening angle of the transducers, a significant interference suppression of the transducers in the vertical direction is achieved and the useful / disturbing ratio of the received electrical signals of the transducers is improved.

to Achieving a directional characteristic of the underwater antenna in the horizontal direction are with the received signals of the transducers so-called group signals formed by the reception signals are time-delayed, that they relate to a main direction of the directional characteristic are concave to each other, and then added together and the sum signal is normalized. The delay time, by which the respective received signal is delayed, is by the position of the respective transducer with respect to the desired Main direction of the directivity determined. By different sized Time delays can have a variety of directional characteristics are formed, all around different sized horizontal Angles are pivoted against the normal of the antenna. The swivel angle The directional characteristic with maximum sound reception is the bearing angle below the sound source seen from the underwater antenna becomes. This bearing angle is also called bearing to the sound source.

at Submarines for the realization of side or side mirrors equipped with a so-called Flankarray, that is one horizontally mounted on the side wall of the submarine linear antenna, which has a plurality of juxtaposed hydrophones, you are increasingly on to the control and port side Linear antenna by planar antennas described above To replace type, to improved noise relief in the vertical direction to achieve. Since in these planar antennas, the main sound receiving direction in vertical direction always at right angles to the antenna carrier aligned when growing the surface antenna on it to be respected that of the transducer elements receiving carrier essentially vertically aligned with the submarine to avoid that about the vertical directional characteristic with the relatively wide opening angle in the vertical direction interference from sound reflections on the seabed or on the water surface in the Receiving signals increasingly noticeable, depending on the depth of the submarine to a considerable extent can. A vertical attachment of the surface antenna but requires the cylinder-like shape of the submarine a relatively complex support structure of the antenna carrier.

Of the Invention is based on the object, a sonar device of to improve the initially mentioned type such that the orientation of the Sound main reception direction of the underwater antenna in the vertical regardless of the mounting position of the underwater antenna on a platform can be adjusted as desired.

The Task is according to the invention by the features solved in claim 1.

The sonar device according to the invention has the advantage that the orientation of the bisector of the vertical opening angle or the axis of the vertical component of the directional characteristic of the underwater antenna can be variably aligned according to the number of held sets of converter-specific delay times in the time delay elements. In a tilted relative to the vertical installation of the underwater antenna, the axis of the directional characteristic is then pivoted vertically by the set in the transducers transducer-specific delay times in the horizontal. The delay times to be set in the time delays are after cultivation of the underwater antenna to the platform, z. B. to the side wall of a submarine, preferably from the outside. In addition, the possibility is opened to change the orientation of the directional characteristic during use, for. B. the submarine operates very close to the seabed or near the water surface. In the first case, the directional characteristic would then be swiveled slightly upwards and in the other case downwards in order to block out disturbing backscatters from the seabed or the water surface. The adjustment of the vertical orientation of the directional pattern of the underwater antenna after cultivation or during use also leaves the directional generator for the horizontal directional characteristic of the underwater antenna undamaged changed. Even the existing wiring between the underwater antenna and the direction generator need not be changed, since the signal processing components for the transducer elements can be assigned to each transducer as an electronic module or integrated into the converter and then connect the outputs of the electronic components by means of the existing wiring to the direction generator are.

expedient Embodiments of the invention Sonar device with advantageous developments and refinements The invention will become apparent from the other claims.

According to one advantageous embodiment of the invention are the electrical Output of each of the mutually arranged transducer elements a converter, an A / D converter and a converter Time delay element downstream in the order named and the outputs of all time delay elements at a summing amplifier with downstream averaging device connected to the output of the electrical receive signal of the Converter is removable.

Around without much technical effort a very accurate Setting the time delays using the delay times to reach, which is always only an integer multiple of a sampling interval of an A / D converter are according to a preferred embodiment of the invention, the A / D converter clocked at a sampling rate that is significantly higher than the sampling rate of the transducers required by the sampling theorem. With the help of a summing amplifier with averaging Downstream decimation filter will then be the desired Sample rate for the received signals restored.

The The invention is based on an illustrated in the drawing embodiment described in more detail below. It show in more schematic Presentation:

1 a side view of a planar trained underwater antenna for a sonar device,

2 a bottom view of the underwater antenna in the direction of arrow II in 1 .

3 a front view of the underwater antenna in the direction of arrow III in 2 .

4 a block diagram of the sonar device,

5 a block diagram of an electronic unit for forming the electrical reception signals of the underwater antenna in 4 .

6 a same representation as in 3 the underwater antenna in the mounted position on the side of a submarine.

In the 4 and 5 in its entirety shown in the block diagram sonar device, which is used for example for aiming sound sources in the water, has an acoustic underwater antenna designed as a surface antenna 11 and circuitry for signal processing from the underwater antenna 11 delivered electrical signals. In the 1 to 3 in different views schematically sketched underwater antenna 11 has a transducer arrangement 12 from a variety of transducer elements 13 standing on a support 14 from each other, preferably evenly spaced. The transducer elements 13 are arranged in columns and rows, wherein in Antenneneinsatzposition the transducer elements 13 in the rows horizontally next to each other and the transducer elements 13 are arranged in the columns with each other. The antenna carrier 14 can be oriented vertically or inclined relative to the vertical, as in 6 is illustrated. By means of a signal processing of the electrical output signals of the transducer elements carried out in the circuit arrangement which will be described below 13 form all arranged in a column with each other transducer elements 13 an electroacoustic transducer 15 , also called staue, ( 4 and 5 ), so that one of the number of columns corresponding number of transducers 15 are arranged horizontally next to each other at the same distance from each other and each one from the electrical output signals of the transducer elements 13 provide a composite electrical reception signal. In the embodiment of 1 each form six transducer elements 13 a converter 15 where the number of transducer elements 13 , in 5 denoted by N, may be arbitrary. The larger N, the smaller the resulting vertical opening angle φ of the directional characteristic of the underwater antenna 11 ( 6 ).

As in the block diagram of 5 is shown at the electrical output of each transducer element 13 the series connection of an amplifier 16 , an A / D converter 17 and a time delay element 18 connected. All outputs of the time delay elements 18 leading to a converter 15 , ie the number N of mutually arranged transducer elements 13 belong to a summing amplifier 19 connected, whose sum signal is a dividing 20 is supplied, in which the sum signal by dividing by the number N of the existing transducer elements 13 normalized. The divider 20 is a decimation filter 21 downstream, whose output 22 the elek tric signal output of a converter 15 forms, at which the electrical received signal of the converter 15 is removed.

wobei n = 1, 2, ... N, c die Schallgeschwindigkeit im Wasser und d der Abstand zwischen zwei untereinander angeordneten Wandlerelementen 13 ist.In the summing amplifier 19 become the amplified and analog / digital converted electrical output signals of a converter 15 associated, mutually arranged transducer elements 13 added. For this purpose, the digitized output signals are delayed in a suitable manner. In every time delay element 18 is stored at least one delay time T _n (α ₁ ) (n = 1, 2, ... N), wherein the stored delay time by the desired orientation of the main sound receiving direction of the underwater antenna, as the main axis of the directivity of the underwater antenna 11 referred to, in the vertical and by the position of the transducer element 13 is determined with respect to this orientation. Exemplary is in 3 the desired vertical component of the main sound receiving direction with 23 designated. This is opposite the antenna normal 24 pivoted about the vertical angle α ₁ . The in each time delay element 18 a converter 15 Time delay T _n (α ₁ ) to be set is calculated according to

where n = 1, 2,... N, c the speed of sound in the water and d the distance between two mutually arranged transducer elements 13 is.

These delay times T _n (α ₁ ) for N transducer elements 13 will be in the N time delays 18 stored and can be called from the outside. If the Schallhauptempfangsrichtung the converter 15 can be aligned differently in the vertical several times, so are in each of the N time delay elements 18 a plurality of delay times T _n (α _i ) with i = 1, 2, ... k stored separately and called in the time delay elements 18 can be adjusted. The sentences in the time delays 18 a converter 15 stored and respectively called delay times T _n (α _i ) with n = 1, 2, ... N and i = 1, 2, ... k are in all converters 15 identical.

To those in the time delays 18 a converter 15 for the individual transducer elements 13 required delay times T _n (α _i ) to set as accurately as possible, which is always only an integer multiple of a sampling interval of the A / D converter 17 can be the A / D converters 17 sampled at a much higher sampling rate than would be required by the sampling theorem. Through the decimation filter 21 is then changed from the high sampling rate back to a low sampling.

In order to attenuate the sidelobes in the vertical component of the directional characteristic, the output signals of all (six in the embodiment) each become a converter 15 associated transducer elements 13 subjected to an amplitude graduation, wherein in each transducer 15 successive amplitude graduation is the same. For this purpose is between the time delay elements 18 and the inputs of the summing amplifier 19 one multiplier each 31 arranged, which multiplies the digital signal by a factor determined by the position of the transducer element 13 is determined in the vertical direction, wherein the factor, starting from the average transducer elements 13 to the outer transducer elements 13 decreases. At six transducer elements 13 per converter 15 and a z. B. binomial amplitude graduation are then in the multipliers 31 set multiplication factors, starting from the top first transducer element 13 associated multiplier 31 to the lowest sixth transducer element 13 associated multiplier 31 ,: 0.1; 0.5; 1; 1; 0.5; 0.1.

In the 5 represented electronic components of all a converter 15 forming transducer elements 13 are structurally in an electronics unit 25 summarized, at whose inputs the mutually arranged transducer elements 13 a column are connected and at the signal output 22 the received signals of the converter 15 are removable. All electronic units 25 are, like this in 4 is shown with their signal outputs 22 at a known directional designer 26 connected. Is in a sonar device, which is equipped with a linear antenna as attached to the side wall Flankarray, the linear antenna against a surface antenna, as shown in FIG 1 to 3 is shown, exchanged, so can the direction generator 26 existing wiring of the underwater antenna 11 be retained without any changes, since only the outputs 22 the electronics unit 25 must be occupied with the existing wiring.

For the detection and bearing of sound sources are in a known manner from the digital samples S _{j of} the received signals of the j converter 15 (with j = 1, 2, ... M) formed temporally successive group signals by adding the received signals according to the different directions θ of the group characteristics after different time delays in accordance with

berechnet, wobei j = 1, 2, ... M, d der horizontale Abstand der Wandler 15 voneinander und c die Schallgeschwindigkeit ist.The delay times t _j (θ) are in a memory 29 are stored for any number of directions θ and are in turn dependent on the position of the transducer 15 to the direction θ according to

where j = 1, 2, ... M, d is the horizontal distance of the transducers 15 from each other and c is the speed of sound.

In 2 is schematically the horizontal component 27 the main axis of a directional characteristic, the by the horizontal tilt angle θ relative to the antenna normal 24 is pivoted. The vertical component 23 the main axis of the directional characteristic is inclined by the vertical angle α ₁ ( 3 ).

All the levels of the group signals which have been formed for the different reception directions θ are in the block 28 stored. The receiving direction θ with the largest level is defined as the bearing to the target.

In 6 is schematized the cultivation of the described underwater antenna 11 on a side wall shown in section 30 sketched out of a submarine. The antenna standards 24 the plan on the ship's side 30 adjacent underwater antenna 11 is due to the construction obliquely downwards. At the relatively large vertical opening angle φ of the underwater antenna 11 would receive on their directional characteristics to a greater extent ground echoes, resulting in a poor payload / noise ratio of the received signals of the converter 15 would lead. To avoid this, the directional characteristics of the underwater antenna must be 11 be aligned in the vertical so that the bisector of the opening angle φ is aligned approximately horizontally. In the example shown, the directional characteristics must be around the angle α with respect to the antenna normal 24 be swung upwards. In the time delays 18 all transducers 15 For this purpose, the same set of converter element-specific delay times T _n (α) is called and in the time delay elements 18 set. This is the directional characteristics of the underwater antenna 11 around the vertical angle α, as in 6 shown, panned. The now in the time delays 18 set delay times are kept unchanged.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - EP 1176428 B1 [0002]

Claims (6)

Sonar device with an acoustic underwater antenna ( 11 ), which have a plurality of horizontally juxtaposed in antenna deployment position, electro-acoustic transducers ( 15 ), each of which converters ( 15 ) of a plurality of mutually arranged, electro-acoustic transducer elements ( 13 ) and a summator ( 19 ), each of the electrical output signals of all a converter ( 15 ) forming transducer elements ( 13 ) and the averaged sum signal as electrical received signal of the converter ( 15 ) and with a direction builder ( 26 ), to receive in the horizontal plane against each other angularly offset directional signals received signals of the converter ( 15 ), characterized in that each transducer element ( 13 ) a time delay element ( 18 ) in which at least one delay time (T _n (α ₁ )) at the time delay of the electrical output signal of the transducer element ( 13 ) is adjustable by a desired vertical alignment of the main sound receiving direction ( 23 ) of the underwater antenna ( 11 ) and the position of the transducer element ( 13 ) is determined with respect to this orientation, and that in a converter ( 15 ) set at least one set of converter element-specific delay times (T _n (α ₁ ), where n = 1, 2, ... N) in all transducers ( 15 ) is identical. Sonar device according to claim 1, characterized in that in each time delay element ( 18 ) at least two delay times (T _n (α ₁ ), T _n (α ₂ )) for two by a vertical angle (α ₁ , α ₂ ) against each other pivoted orientations of the main sound receiving direction ( 23 ) of the converter ( 15 ) are stored, which are accessible for setting from the outside. Sonar device according to claim 1 or 2, characterized in that the electrical output of each transducer element ( 13 ) an amplifier ( 16 ), an A / D converter ( 17 ) and a time delay element ( 18 ) are connected downstream in the stated order and that the outputs of all time delay elements ( 18 ) on a summation amplifier ( 19 ) with downstream averaging agent ( 26 ) are connected to the output ( 22 ) the received signal of the converter ( 15 ) is removed. Sonar device according to claim 3, characterized in that in each circuit branch between the electrical output of each transducer element ( 13 ) and the input of the summing amplifier ( 19 ), preferably the time delay element ( 18 ), a multiplier ( 31 ) with one for a amplitude graduation of the output signals of a converter ( 15 ) associated transducer elements ( 13 ) adapted multiplication factor is arranged. Sonar device according to claim 3 or 4, characterized in that the A / D converters ( 17 ) are clocked at a higher clock frequency than the sampling rate of the received signals and that the averaging device ( 20 ) a decimation filter ( 21 ) is connected downstream. Sonar device according to claim 5, characterized in that all a converter ( 15 ) associated electrical components such as amplifiers ( 16 ), A / D converter ( 17 ), Time delay elements ( 18 ), Multipliers ( 31 ), Summing amplifier ( 19 ), Averaging ( 20 ) and decimation filter ( 21 ) to an electronics unit ( 25 ) with one of the number (N) of the transducer elements ( 13 ) of a converter ( 15 ) corresponding number of inputs and one output ( 22 ), at which the electrical received signal of the converter ( 15 ) pending.