EP3152589A1

EP3152589A1 - Method for establishing an underwater map, underwater map, and vehicle

Info

Publication number: EP3152589A1
Application number: EP15737968.6A
Authority: EP
Inventors: Jeronimo DZAACK
Original assignee: Atlas Elektronik GmbH
Current assignee: Atlas Elektronik GmbH
Priority date: 2014-06-05
Filing date: 2015-04-20
Publication date: 2017-04-12
Also published as: WO2015185033A1; DE102014107974A1

Abstract

The invention relates to a method for establishing an underwater map, said method having the following steps: a) establishing three-dimensional sonar data by means of a first sonar, b) establishing underwater parameters using the established three-dimensional sonar data, and c) adapting an initial underwater map in particular using initial underwater parameters and a correction algorithm which uses the established underwater parameters, such that a new underwater map is obtained.

Description

Method for determining a submarine map,

Underwater map as well as vehicle

The invention relates to a method for determining an underwater map by means of three-dimensional sonar data and a submarine map and a vehicle having the underwater map.

Underwater maps or nautical charts with recorded shoals have the fundamental problem that at the time of publication or use of the card, the realities have often already changed.

For example, it may happen that a river over time rinses sediment at certain points, which creates a risk of collision for ships with a certain draft. In order to prevent this, shoals with a certain safety area are drawn in all the usual nautical charts.

[04] On the other hand, for example, in busy lakes, such as the English Channel,

Watercraft sink and thus avoiding the accident location be mandatory or it is also ships with a certain draft not allowed to run over the place.

[05] In particular for underwater navigation, for example by autonomous underwater or submarine Boats, precise underwater maps are essential for optimal navigation. For example, an underwater object, such as a submarine volcano or a subsea mountain, is modeled using geometric bodies, and sonar data is optimally computed based on this model, allowing more accurate, more accurate navigation.

[06] In addition, there are other important parameters that can or should be included in a submersion map. For example, the salinity, temperature or other information important to the interpretation of sonar data may be recorded in a submarine card.

[07] In general, such maps are laborious to create and are extremely rarely brought up to date. This poses dangers, as optimal navigation or passage through a specific water area can not be guaranteed.

[08] The object of the invention is to improve the state of the art.

[09] The object is achieved by a method for determining a submarine map, the method comprising the following steps: a) determining three-dimensional sonar data by means of a first sonar, b) determining underwater parameters on the basis of the determined three-dimensional sonar data and c) adapting an originating underwater map, in particular with originating underwater parameters, by means of a correction algorithm which uses the determined underwater parameters so that a new underwater map is present.

Thus, a Unterwasserkarte be provided, in which the latest information is at least partially included. In particular, sunken ships can be measured so quickly and, if necessary, a waterway can be cleared for the entire shipping industry or for parts of the shipping industry.

Also, modeled underwater landscapes can be approximated to reality, allowing better underwater navigation, especially for autonomous

Underwater vehicles or submarines, can be guaranteed.

Furthermore, such a map can be quickly transmitted to other drivers or other vehicles, so that they can also access current data. This can significantly increase traffic safety on and in the oceans and rivers.

[13] The following terminology is explained:

In its simplest embodiment, a "Unterwasserkarte" is used in shipping (two-dimensional) sea chart including displayed

Sea water depths. This means that the underwater map is a two-dimensional upper water map, in which the corresponding depths are drawn. Such maps are used in particular by sailors for navigation.

Submarine maps can also provide a more detailed picture of the conditions under water. In particular, it is a complete three-dimensional data set in which all natural and artificial objects are recorded, which are located below the surface of the surface.

[16] The resolution of objects in such underwater maps may be one meter or even less. The resolution depends in particular on the way in which the data are obtained and in the present case in particular by the 3D sonars used.

In this special form, a submarine map for autonomous underwater vehicles (AUV) or submarines of utmost importance, as with the sonars, for example, with the forward-looking sonar of a submarine, scanned the environment and with the present underwater map can be adjusted so that the current position can be determined exactly.

[18] "Three-dimensional sonar data" means all sonar data that can convey a spatial impression of underwater objects Three-dimensional sonar data are determined in particular by means of a 3D sonar.

The present "sonar" is in particular a 3D sonar Also, the sonar may for example comprise a plurality of spaced apart from each other having a defined hydrophones, which can determine a reflection subject under water based on the different duration of an emitted sound signal.

In particular, different information can be obtained by the underwater sound signals used, their frequencies and intensity as well as their time course and the corresponding Hydrophonausgestaltung, which determine a detailed image of the underwater object.

[21] In a primitive form, the sonar corresponds to a simple echosounder in which a specific water depth is determined via a certain point above water, which is determined, for example, by means of GPS or Galileo. By displacing the echosounder and recording the associated change in location, an image of the seabed can thus be determined.

[22] The "specific underwater parameters" are all data obtained from the underwater sound signals by means of the sonar, such as underwater depth or the distance to an underwater object.

[23] An "original underwater map" is an existing underwater map Origin submarine map may already have parameters such as water depth or distance to an underwater object, so that the

Origin submarine card has origin submarine parameters. In particular, it is an electronic card.

[24] "Adjusting" means in this case in particular that the originating underwater map is modified according to the determined underwater parameters.

[25] This adjustment is done by means of a

"Correction Algorithm", which determines the influence of certain underwater parameters on the new underwater map.

In its simplest form forms the

Correction algorithm between the original underwater parameter and the associated new underwater parameters determined by the three-dimensional sonar data an average value. Thus, for example, a registered depth of origin may have been 37m and the depth of the sea determined by the sonar 39m, so that the new submarine map for the present depth assumes a value of (37m + 39m) / 2 = 38m.

Consequently, therefore, the present method does not radically redetermine an existing underwater map, but merely adapts it to an adapted one, which, for example, slowly approaches a real value by repeatedly performing it. [28] In another embodiment, further three-dimensional sonar data are determined by means of further sonars and then steps b) and c) are carried out in each case.

[29] Thus, data from various sources can be used to designate a new underwater map.

In the present case, for example, one sonar may be a forward-looking sonar of a submarine, while another sonar may be a pure sonar, for example, which is arranged on a ship. In addition, for example, the 3D sonar of a research vessel can be evaluated, whose parameters are then also included in the new underwater map.

[31] In order not to use a new card in turn as a new source card then to generate a new card again, further three-dimensional data can be determined by means of further sonars and at least two or more sonar data of different sonars are fused and then the steps b) and c).

[32] When merging, both the data itself and the underwater parameters obtained from the three-dimensional sonar data can be fused. In the case of "merging", it is possible to use a weighting or other functions similar to the correction algorithm. [33] In a further embodiment, the three-dimensional sonar data of the first sonar and / or in each case the three-dimensional sonar data of the further sonar have a reliability indicator.

[34] Thus, the reliability of the sonar and thus of the particular subsea parameters can be estimated.

In particular, it can be assumed, for example, that military sonars of a submarine provide more accurate data than, for example, the echo sounder of a fishing trawler. This means that the correction algorithm, for example, weights the data of the submarine higher than, for example, the data of the fish trawler.

Thus, for example, each sonar can still provide an identifier which transmits the model of the sonar and thus the accuracy of the sonar. This information can be stored in a database, for example, when adjusting the

Origin underwater maps by means of the correction algorithm.

[37] In its simplest form, for example, the inaccurate sonar data can receive a connoisseur 1 and the most accurate, for example, a connoisseur 10. Sonars of good quality, for example, would have a connoisseur 8 in such a scheme. Not only linear values but also, for example, logarithmic values could be used, so that, for example, 1,000 measurements of different fish trawlers would be equivalent to a submarine measurement. [38] This means that, therefore, based on the

Reliability indicator of the correction algorithm can perform a weighting.

[39] "Weighting" is to be understood as meaning that the influence of the change in the origin map has a functional relationship with the reliability indicator.

[40] To different underwater parameters

To be able to provide these can be one

Area coordinate, a space coordinate, a flow, a tiedenabhängige depth and / or salinity include. In the area and space coordinate, for example, a Cartesian coordinate system can be used. Furthermore, the area coordinate can be represented for example by a polar coordinate system or the space coordinates can be represented by means of a cylinder base or other bases. The flow may in particular include the expansion of the flow and the velocity of the flow. Also, the correction algorithm may consider this flow when adjusting the source submarine map, as flow often has an impact on the quality of the particular subsea parameters.

Especially in very shallow waters, as they are present for example in the North German bay, the underwater parameters may have a tiedenabhängige depth in which based on the state of the moon certain information can be obtained and a Navigate, for example, at high tide still possible, but at low tide is not feasible.

[42] Thus very reliable data of a

Origin submarine parameters may not be easily modified, a source underwater parameter may have a confidence indicator.

For example, a sunken wreck may have been measured by divers by hand, so that, for example, the extent of the wreck is determined exactly. If underwater parameters, which were determined by means of three-dimensional sonar data, result in a greater or lesser length of the wreck, then the confidence indicator can show that the length of the wreck may not be changed or only marginally changed.

[44] In another embodiment, adjustments above a threshold are provided separately in the new submarine card.

[45] Thus, a human observer can again check whether the adjustments are consistent if necessary, or whether a reference measurement should be made. Furthermore, acute changes in the maps can be recorded, so that ships can avoid an acute danger spot.

[46] Also, for example, a

Underwater pipeline structure thus be examined for leakage of the oil, especially since leakage of the oil has other propagation properties for sound than usual seawater, so that the values deviate greatly from previous values. Thus, therefore, so can

Monitoring functions are found in which a source submarine card with the input to solve the problem described procedures are found.

In order to obtain a high quality of three-dimensional sonar data, at least two sonars can be arranged stationary or quasi stationary.

[48] For example, another sonar may be arranged on a foundation on the seabed of one of the sonars and on a quay wall. On the one hand, high-quality three-dimensional data of one object between the two sonars can be determined, on the other hand, a good quality of the three-dimensional sonar data can be provided.

[49] "Stationary" means that the sonars do not essentially move, and "quasi-stationary" means that any movements can be determined or calculated accordingly. For example, buoys can be anchored to the seabed, which have a sonar and which can move according to a current. Due to a GPS signal, however, the current location can additionally be determined at the respective time of the determination of the three-dimensional sonar data, so that a correction can take place.

[50] In particular, in the navigation of submarines, artificial or natural underwater structures are modeled to obtain better navigation data. Often Thus, these origin underwater maps are modeled using geometric objects such as cuboid, so that this represents a first approximation of reality. In order to improve the modeled source submarine map, the method mentioned for solving the problem can also be applied to such modeled submarine maps.

[51] The invention can also serve to calibrate position information. Especially with a longer maneuver of an AUV or submarine underwater it can be due to the environmental conditions and by measurement inaccuracies to a shift of the coordinate system of the

Location information coming.

[52] By capturing real-time environmental data and comparing it to digital maps (such as distinctive natural and unnatural points), the map can be calibrated back to real world coordinates. All systems based on it (e.g., navigation, surveying, etc.) become more accurate and reliable.

[53] In a further aspect of the invention, the object is achieved by a underwater map, in particular an electronic underwater map in a computer, which corresponds to one by means of a submarine map, which was determined by a method described above.

[54] Such an underwater map can be made available to an operator, for example by means of a virtual reality, or can be two-dimensional, for example by providing any cuts through the underwater map give the operator an impression of the underwater area.

[55] In a further aspect of the invention, the object is achieved by a vehicle, in particular a watercraft, which has a submarine map described above.

[56] In the following, the invention will be explained with reference to exemplary embodiments. Show it

Figure 1 is a highly schematic representation of a vertical section through three different underwater maps at an identical location and

Figure 2 is a highly schematic representation of a vertical section through a modeled source underwater map and a new underwater map at an identical location.

[57] On a water route, a ship sailing on the water surface 101 sank on the seabed 103. After the accident, a rough model 105 of the sunken ship in the form of a cuboid, which completely accommodates the ship, was marked on the damaged area in a submarine map. If ships have a draft greater than the depth of defense 107, the accident location for these ships is blocked. In order to give other vessels as soon as possible the opportunity to run over the accident site, the radius of the damaged area is traversed by means of a simple echo sounder and determines the corresponding depth of water at several points. From the location-dependent depth values determined using the depth sounder and the modeled sunken ship 105, a new underwater map with a first approximation 111 of the wreck is created. In this case, the depth of security has increased 107, so that ships with greater depth may drive over the accident site.

Subsequently, a ship with a high-resolution 3D sonar with very high quality and very good resolution sent to the accident site to measure the sunken wreckage. The resulting SD data show the highest reliability indicator. Thus, the underwater map of the first approximation, which in the present case is the new origin underwater map, is adapted in such a way with the data determined by the high-resolution 3D sonar, that the resulting new

Underwater map to 90% from the data of the high-resolution 3D sonar and thus the data of the second approximation and 10% from the data of the first approximation 111 is formed.

[60] The now new submarine map of the second approximation 113 has a new depth of defense 117, which allows other vessels with a greater depth to pass through the site. In addition, the lateral side safety distance 109 has been reduced, so that a more accurate underwater image of the damaged area is present. [61] In an alternative, an underwater range was modeled using a model 205, which has model cuboid 207. This Model 205 allows a submarine to better navigate using sonar data.

[62] Over time, the underwater mountains were repeatedly run over by a research vessel with high-resolution sonar and all determined parameters were fused into a total set of parameters. In the present case, the determined by means of the research vessel

Overall parameter set has a high reliability indicator. This total parameter set is merged with the modeled Unterseegebirge by means of a correction algorithm, so that a new Unterwasserkarte is given.

[63] The resulting underwater mountains according to the new underwater map are shown by curve 213.

Reference sign list

101 water surface

103 seabed

105 Model of a sunken ship 107 Safety depth 109 Safety distance

111 First approximation 113 Second approximation

117 New depth of security

205 Model of an underwater mountain

207 model cuboid

213 Underwater Mountains according to new underwater map

Claims

Claims:

A method of detecting a submarine map, the method comprising the steps of:

a) Determining three-dimensional sonar data by means of a first sonar,

b) determination of underwater parameters on the basis of the determined three-dimensional sonar data,

- c) adapt an originating underwater map, in particular with originating underwater parameters, by means of a correction algorithm which uses the determined underwater parameters, so that a new underwater map exists.

2. The method according to claim 1, characterized in that further three-dimensional sonar data determined by means of further sonars and then each of the steps b) and c) are performed.

3. The method according to claim 1, characterized in that further three-dimensional sonar data determined by means of further sonars and fused at least two or more sonar data different sonars or their particular underwater parameters and then the steps b) and c) are performed.

4. The method according to any one of the preceding claims, characterized in that the three-dimensional sonar data of the first sonar and / or in each case the three-dimensional sonar data of the other sonars have a reliability indicator.

5. The method according to claim 4, characterized in that based on the reliability indicator of

Correction algorithm performs a weighting.

6. The method according to any one of the preceding claims, characterized in that the underwater parameters comprises a surface coordinate, a spatial coordinate, a flow, a tiedenabhängige depth and / or salinity.

7. The method according to any one of the preceding claims, characterized in that the original underwater parameters have a confidence indicator.

8. The method according to any one of the preceding claims, characterized in that adjustments above a threshold are provided separately in the new submarine card.

9. The method according to any one of claims 2 to 8, characterized in that at least two sonars are arranged stationary or quasi-stationary.

10. The method according to any one of the preceding claims, characterized in that a component of the original underwater map is modeled.

11. Unterwasserkarte, in particular electronic Unterwasserkarte in a computer, which is a determined by means of a method according to one of the preceding claims Unterwasserkarte.

12. vehicle, in particular watercraft, which has a Unterwasserkarte according to claim 11.