AU748351B2 - Transmission antenna for a sonar system - Google Patents
Transmission antenna for a sonar system Download PDFInfo
- Publication number
- AU748351B2 AU748351B2 AU84231/98A AU8423198A AU748351B2 AU 748351 B2 AU748351 B2 AU 748351B2 AU 84231/98 A AU84231/98 A AU 84231/98A AU 8423198 A AU8423198 A AU 8423198A AU 748351 B2 AU748351 B2 AU 748351B2
- Authority
- AU
- Australia
- Prior art keywords
- transmission antenna
- hollow
- antenna according
- transmission
- hollow cylinder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
- 230000005540 biological transmission Effects 0.000 title claims description 60
- 239000012530 fluid Substances 0.000 claims description 5
- 229910000838 Al alloy Inorganic materials 0.000 claims description 2
- 239000004411 aluminium Substances 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- 239000006262 metallic foam Substances 0.000 claims description 2
- 240000007594 Oryza sativa Species 0.000 claims 1
- 235000007164 Oryza sativa Nutrition 0.000 claims 1
- 239000013013 elastic material Substances 0.000 claims 1
- 239000011148 porous material Substances 0.000 claims 1
- 235000009566 rice Nutrition 0.000 claims 1
- 239000000919 ceramic Substances 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000011161 development Methods 0.000 description 6
- 230000018109 developmental process Effects 0.000 description 6
- 238000010276 construction Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 239000006261 foam material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 230000004308 accommodation Effects 0.000 description 1
- 230000002146 bilateral effect Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
- G01V1/02—Generating seismic energy
- G01V1/143—Generating seismic energy using mechanical driving means, e.g. motor driven shaft
- G01V1/145—Generating seismic energy using mechanical driving means, e.g. motor driven shaft by deforming or displacing surfaces, e.g. by mechanically driven vibroseis™
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0644—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element
- B06B1/0655—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element of cylindrical shape
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
- G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
- G10K9/121—Flextensional transducers
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Remote Sensing (AREA)
- Life Sciences & Earth Sciences (AREA)
- Acoustics & Sound (AREA)
- Geology (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Geophysics (AREA)
- Mechanical Engineering (AREA)
- Multimedia (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
Description
Title Transmission antenna for a sonar system Technical Field The invention concerns a transmission antenna for a sonar system of the type defined in the generic part of claim 1 to be towed by a watercraft.
Background to the Invention To determine the direction, distance, speed and course of a target, broadband sound pulses are emitted by the transmission antenna of the sonar system, which are reflected by the target and are received angle-selectively by a trailing antenna. The transmission antenna is installed on a separate towing body. To achieve great coverage the frequency range of the sound waves :i I: is in the kilohertz range.
S.
In "Underwater Updates" from the "Navy International" May/June 1993, pages 140, 141, a towinq body for a transmission antenna is described, which has a hollow cylinder with elliptical or 2 drop-shaped cross-section and in the towed position carries on the rear side of the top end two laterally extending wings to stabilise its towed position. The towed body is joined to the watercraft with the trailing and towing cable via a fork. The towed body is relatively heavy to achieve the required trailing depth. To pay out and haul in the towed body and the trailing antenna from the watercraft a pulling-in device is on board, •e ~which has a winch with one winch drum for the towing cable, a further winch drum for the towing antenna and a removing device for the trailing body and the trailing antenna. The paying out and the hauling in of the trailing antenna and of the towing body is carried out separately. Even in the case of a streamlined shape the towing body has a relatively large resistance in the water and together with the removing device requires space for its accommodation on the deck of the watercraft, leading to problems of space, in particular on smaller ships, like corvettes.
141/ i i The Australian patent application AU 9540518 A describes a trailing antenna, whose electro-acoustic transducers contain a hollow cylinder made of polarised piezo-ceramics with a concave internal sheathing and a convex external sheathing. The internal sheathing is glued to the inside surface and the external sheathing on the outside surface of the hollow cylinder. These transducers are particularly suitable for the reception of sound waves. When using them as transmission transducers with particularly high sound level, there is, however, the danger that the glued joint will be ruptured due to the large swings of the internal and external sheathings.
Summary of the Invention The present invention may provide a transmission antenna for a sonar system to be towed by a watercraft, with at least one cylindrical transmission transducer, whose diameter is smaller than the wave length of the sound to be radiated and whose height is greater than the diameter wherein the transmission transducer contains a hollow cylinder made of piezo-ceramics or piezo-ceramic discs or therphenol and has a convex external sheathing with an outward arched wall and a concave internal sheathing with a wall arched into the interior of the hollow cylinder, characterised in that the hollow cylinder is mechanically pre-tensioned in the direction of its height by bilateral covers made of metal, that the covers, external sheathing and internal sheathing form an enclosed hollow ring from metal which surrounds the hollow cylinder at a distance in the radial direction, that half of the difference of the outside and inside diameters of the hollow ring is considerably smaller than the height of the hollow cylinder and that a plurality of transmission transducers are lined up in a hose behind each other with their heights aligned in the axial longitudinal direction of the hose.
It is an advantage of at least one embodiment of the invention to produce a transmission antenna of the type mentioned in the introduction, which requires little space, facilitates a simple bringing in and paying out and which due to its robust construction can be used for the determination of positions over large distances.
Each transmission transducer of the transmission antenna has a piezo-ceramic hollow cylinder with a convex external sheathing and a concave internal sheathing between two covers, the height of which is mechanically pre-tensioned by the covers. The hollow cylinder can be also constructed from piezo-ceramic discs or manufactured from therphenol. The external sheathing, internal sheathing and the covers form an enclosed hollow ring which surrounds the hollow cylinder. In the radial direction there are hollow spaces between the hollow cylinder and the external sheathing as well as between the hollow cylinder and the internal sheathing. When transmitting sound waves, radial and/or axial oscillations of the hollow cylinder are transferred to the hollow ring surrounding it and transmitted in the ratio of the thickness of the hollow ring to its height.
IS The thickness of the hollow ring is determined by the difference between the diameters of the external sheathing and i the internal sheathing. By this construction of the *g *•go *o transmission transducer a movement transformation is carried out, which allows an increase of the stroke of the transmission transducer in the radial direction while having the same radiation capacity and accordingly increases the frequency range towards the lower frequencies in the same ratio.
The advantage of the transmission antenna according to claim 1 is that its resistance to flow and the flow noises are small along the transmission antenna, since its diameter is matched to suit the trailing antennas, so called thin-line streamers, which are used to receive low-frequency sound waves. The particular advantage of the transmission antenna according to claim 1 is that the transmission transducer is accommodated in a hose, that the hose with the transmission transducers and the trailing antenna forming a trailing unit can be paid out and pulled in using the same pulling-in device, wherein its transmitting portion is in the vicinity of the towing ship and its receiving portion is trailed at a greater distance from it.
Thus a special towing body for the transmission antenna has become superfluous, as has separate mechanical joining to the towing watercraft, and the spatial requirement on board became smaller.
*o From EP 0 251 797 a cylindrical transmission transducer is already known, which transmits at 15 kHz. It has an external sheathing and a cover which are intimately joined with the piezo-ceramic hollow cylinder. With this transmission transducer a relative band width of 40 is achieved. Sound waves of 1.5 kHz cannot be radiated, since the ceramic cylinder cannot carry out a 10-fold stroke which would be required for the same emission output as for 15 kHz.
The advantageous development of the transmission antenna according to claim 2, wherein the height is 10 times that of the thickness of the hollow ring, the dimensioning results in a transmission transducer the output of which is constant over a wide frequency range from 1 kHz to 10 kHz and is, for example, 104 N/m 2 The advantageous development of the transmission antenna according to the invention in accordance with claim 3 permits a thin-walled construction of the hollow ring which, due to its elliptical cross-section, precludes buckling even at large oscillation amplitudes. The advantageous development of the transmission antenna according to claim 4 permits a simple assembly of the transmission transducer, the pre-tensioning of which can be adjusted by the screw connection.
According to the advantageous development of the transmission antenna in accordance with claim 5 the hollow ring is made of aluminium or an aluminium alloy to keep the weight of each transmission transducer low.
By filling the hollow spaces of the hollow ring with foam material or metal foam according to the advantageous developments of the transmission antenna in accordance with the claims 6 and 7, the impedance of the transmission transducer, which depends from the ratio of its diameter to the wave length, is adjusted to suit the wave resistance of the water and a buoyancy is produced. When the hose of the transmission S antenna is additionally filled with a fluid, as this is known in conjunction with trailing antennas for a further increase of the buoyancy, the hollow ring has a compensating orifice for the fluid exchange when the transmission antenna is towed at oo different trailing depths.
o •According to the advantageous development of the transmission antenna according to the invention in accordance with claim 9 the hose is filled with a gel, which is liquid during the filling and afterwards settles into its jelly-shaped state. The advantage of using gel instead of oil is that in the case of the hose becoming damaged no environmental pollution will be caused by the oil and the gel has a self-healing effect.
Brief Description of the DrawinQs The invention is described in detail based on an embodiment for a transmitting antenna of a sonar system to be towed by a watercraft. They show in: Fig.l a sonar system with transmission antenna and trailing antenna for reception, Fig.2 a transmission transducer, and Fig.3 a sectioned illustration of the transmission transducer.
On a watercraft 1 a sonar system 2 is installed to determine target data of a ship or submarine. Sound pulses are emitted by a transmission antenna 3 and reflected portions are received by a trailing antenna 4. The transmission antenna 3 and the trailing antenna 4 are connected with the sonar system 2. With its antennas, from the sonar system 2, broadband sound waves are emitted in a frequency range of 1-10 kHz and the reflected portions are received and evaluated.
The transmission antenna 3 contains in a hose a plurality of cylindrical transmission transducers, whose diameters are considerably smaller than their lengths. The diameter is, for example, 7 cm, its length is approx. ten times that. Such a transmission transducer is illustrated in Fig.2. The external contour of the transmission transducer is barrel-shaped. The acoustically active part is a piezo-ceramic hollow cylinder 11 ,o ~or a pile of discs from piezo-ceramics. The hollow cylinder 11 has ring-shaped covers 12, 13 to produce a mechanical pretensioning. An outward arched external sheathing 14 surrounds the hollow cylinder 11. An internal sheathing 15 with a concave wall is in the interior of the hollow cylinder 11. The external sheathing 14 and the internal sheathing 15 are joined with each other via the covers 12, 13 and form a hollow ring having an essentially elliptical cross-section. The pre-tensioning on the hollow cylinder 11 is exerted by means of a screw connection 16, 17. The hollow spaces 19, 20 of the hollow ring between the external sheathing 14 and the hollow cylinder 11 as well as between the internal sheathing 15 and the hollow cylinder 11 are filled with foam material, which is electro-deposited on the hollow cylinder 11, and serves for the adjustment of the impedance of the transmission transducer to suit the wave resistance Z of the water. The hose, which accommodates a plurality of such transmission transducers, is filled with a gel, which has low viscosity during the filling and settles after a certain period after the filling. Such a gel is selfhealing when the hose of the transmission antenna becomes damaged.
To transmit sound waves a sinusoidal alternating current is connected via electrodes to the outside and inside jacket of the hollow cylinder 11, which AC will cause the hollow cylinder 11 oscillate and to carry out a sinusoidal axial movement X.
The axial movement X leads to a radial movement of the external sheathing 14 and of the internal sheathing 15 of the hollow ring, which is grater by the ratio of a to b, wherein a is the height of the transmission transducer and b is the difference S of the diameters of the external sheathing and the internal sheathing. By virtue of this movement transformation it is possible to produce sound waves in a wide frequency range with S: a hollow piezo-ceramic cylinder 11, the diameter of which is considerably smaller than the wave length of the sound waves.
e In the case of an output of N 10 kW/m 2 to be radiated, the amplitude of the sound pressure in the water is Po (Z N) 1.2 105 Pa. The speed of sound V is joined with the ego.ei pressure of the sound through the wave resistance Z 1.5 106 kg/m 2 s of the water, and is determined from the time derivation of the sinusoidal movement X. Its amplitude depends from the amplitude Xo of the movement and the frequency w. To produce a sound pressure having an amplitude Po 1.2 105 Pa in water, the amplitude of the movement in the water is Po Xo W) Z 1.2 105 1 Xo /m/ 10 6 2 7r.f In the case of a frequency of f 10 kHz, the amplitude is Xo 1.2 gm, in the case of a frequency of 1 kHz the amplitude 1 is Xo 12 gm. Therefore the external sheathing 16 of the transmission transducer has to carry out a movement of 1 Mm to jm, depending from the frequency, to enable to radiate a broadband output of 10 kW/m 2 In the case of a ratio of a:b 10:1, a movement transformation of 1:10 is achieved, i.e. an 9 axial movement X of the hollow cylinder 11 is transformed into 15 a radial movement r 10 X of the hollow ring.
9.
Fig.3 shows a section across the transmission transducer with its external sheathing 14, the hollow cylinder 11 and its S* internal sheathing 15 in the region of the largest diameter of the transmission transducer.
9o
Claims (7)
- 3. A transmission antenna according to claim 1 or 2, characterised in that the covers have an annular shape and the hollow ring has an elliptical cross-section.
- 4. A transmission antenna according to claim 3, characterised in that the hollow ring can be divided and has a screw connection. A transmission antenna according to any one of the claims 1 to 4, characterised in that the hollow ring is made of aluminium or an aluminium alloy.
- 6. A transmission antenna according to any one of the claims 1 to 5, characterised in that the hollow spaces of the hollow ring between its walls and the hollow cylinder are filled with an elastic material.
- 7. A transmission antenna according to claim 6, characterised in that the hollow spaces of the hollow ring between its walls and the hollow cylinder are filled with a metal foam having closed pores. iF':
- 8. A transmission antenna according to any one of the claims 1 to 7, characterised in that the hose is filled with a fluid and the hollow ring has a compensating orifice for fluid exchange.
- 9. A transmission antenna according to claim 6, characterised in that the fluid is a gel which can settle in the hose after the filling.
- 10. A transmission antenna substantially as described herein with reference to the drawings. Dated this sixth day of March 2002 STN Atlas Elektronik GmbH Patent Attorneys for the Applicant: F B RICE CO
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1997143096 DE19743096C1 (en) | 1997-09-26 | 1997-09-26 | Transmission antenna for sonar system for towing behind a waterborne vehicle |
| DE19743096 | 1997-09-26 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU8423198A AU8423198A (en) | 1999-04-15 |
| AU748351B2 true AU748351B2 (en) | 2002-06-06 |
Family
ID=7844078
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU84231/98A Ceased AU748351B2 (en) | 1997-09-26 | 1998-09-14 | Transmission antenna for a sonar system |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0905676B1 (en) |
| AU (1) | AU748351B2 (en) |
| DE (1) | DE19743096C1 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE20105592U1 (en) * | 2001-03-30 | 2002-05-23 | Siemens Ag | Sensor device with a passive component for querying and reporting a system status of a technical system |
| FR2822960B3 (en) * | 2001-03-30 | 2003-06-20 | Thomson Marconi Sonar Sas | LOW FREQUENCY UNDERWATER DETECTION SYSTEM |
| FR2822959B1 (en) * | 2001-03-30 | 2003-07-25 | Thomson Marconi Sonar Sas | LOW FREQUENCY UNDERWATER DETECTION SYSTEM |
| US6683819B1 (en) * | 2003-01-21 | 2004-01-27 | Raytheon Company | Sonar array system |
| DE102004038034A1 (en) * | 2004-08-05 | 2006-02-23 | Atlas Elektronik Gmbh | Electroacoustic transmitting antenna |
| FR2900504B1 (en) | 2006-04-26 | 2009-11-20 | Thales Sa | METHOD FOR OPTIMIZING THE POWER SUPPLY OF A LINEAR TRANSMITTED TRANSMITTER ANTENNA FOR TRANSMITTING IN OMNIDIRECTIONAL MODE. |
| WO2012034205A1 (en) | 2010-09-13 | 2012-03-22 | Ultra Electronics Canada Defence Inc. | Defocusing beamformer method and system for a towed sonar array |
| RU2477011C1 (en) * | 2011-09-13 | 2013-02-27 | Учреждение Российской академии наук Институт проблем морских технологий Дальневосточного отделения РАН (ИПМТ ДВО РАН) | Antenna module of precision doppler log for deep underwater vehicle |
| DE102011121006B4 (en) * | 2011-10-28 | 2015-08-13 | Atlas Elektronik Gmbh | Electroacoustic transducer |
| DE102015114375A1 (en) * | 2015-08-28 | 2017-03-02 | Atlas Elektronik Gmbh | Drum for a towed antenna, winch for a towed antenna, towed antenna for towing in the water and a ship for towing a towed antenna in the water |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4546459A (en) * | 1982-12-02 | 1985-10-08 | Magnavox Government And Industrial Electronics Company | Method and apparatus for a phased array transducer |
| WO1987005773A1 (en) * | 1986-03-19 | 1987-09-24 | The Secretary Of State For Defence In Her Britanni | Flextensional transducers |
| DE3787677T2 (en) * | 1986-07-02 | 1994-02-03 | Nippon Electric Co | Non-directional ultrasound transducer. |
| US5030873A (en) * | 1989-08-18 | 1991-07-09 | Southwest Research Institute | Monopole, dipole, and quadrupole borehole seismic transducers |
| US5099460A (en) * | 1990-08-13 | 1992-03-24 | Seabeam Instruments, Inc. | Sonar transducer |
| AU692960B2 (en) * | 1994-12-23 | 1998-06-18 | Marschall Acoustics Pty Ltd | Hydrophone |
| DE19607303C2 (en) * | 1996-02-27 | 2000-11-30 | Stn Atlas Elektronik Gmbh | Envelope body to protect a hydrophone arrangement |
-
1997
- 1997-09-26 DE DE1997143096 patent/DE19743096C1/en not_active Expired - Fee Related
-
1998
- 1998-09-14 AU AU84231/98A patent/AU748351B2/en not_active Ceased
- 1998-09-22 EP EP98117957A patent/EP0905676B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0905676A3 (en) | 2001-09-12 |
| AU8423198A (en) | 1999-04-15 |
| EP0905676A2 (en) | 1999-03-31 |
| EP0905676B1 (en) | 2004-11-17 |
| DE19743096C1 (en) | 1999-01-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FGA | Letters patent sealed or granted (standard patent) | ||
| PC | Assignment registered |
Owner name: ATLAS ELEKTRONIK GMBH Free format text: FORMER OWNER WAS: STN ATLAS ELEKTRONIK GMBH |