Patent Publication Number: US-2022221343-A1

Title: Underwater apparatus for image-capturing of the floor of a body of water

Description:
The invention relates to an underwater device with a hyperspectral camera for capturing images of a seabed. Furthermore, the invention relates to an autonomous underwater vehicle and a cable-guided underwater vehicle each having such an underwater device. 
     There exists a need to monitor marine and freshwater ecosystems from both an economic and ecological perspective. One challenge in monitoring ecosystems is that, on the one hand, a fine spatial resolution of the seabed is needed to capture the high diversity of organisms with sufficient accuracy and, on the other hand, a large area must be examined. 
     Underwater devices are known from the prior art which have a camera and by means of which images of the seabed are captured. The known underwater devices are very large and cumbersome. This means that adapting the underwater device to different areas of application requires a great deal of time. In particular, the installation and removal of electrical consumers in the underwater device requires a great deal of time. 
     The object of the invention is to provide an underwater device that can be quickly adapted to the desired field of application and/or purpose. 
     The object is achieved by an underwater device having a hyperspectral camera for capturing images of a seabed, a first housing part, a second housing part releasably connected to the first housing part in a watertight manner and enclosing with the first housing part a cavity in which the hyperspectral camera is arranged, and an electrical energy storage device for supplying electrical energy to the hyperspectral camera arranged in another cavity, wherein the other cavity is separated from the cavity by a wall section of the first and/or second housing part. 
     The underwater device according to the invention has the advantage that it is compactly designed and consists of few components. In addition, the electrical energy storage device is easily accessible so that it can be replaced in a simple and quick manner. Since the other cavity is separated from the cavity in a watertight manner, water can easily be prevented from accidentally entering the cavity when changing the electrical energy storage device. 
     It can also be quickly assembled and disassembled. After the connection between the first housing part and the second housing part has been released, the hyperspectral camera arranged in the cavity can be easily accessed. Furthermore, once the connection has been released, other mechanical components and/or electrical consumers located in the cavity can be easily accessed. As a result, the underwater device can be quickly converted to suit its intended use and/or location. 
     In operation, the underwater device can be arranged partially or completely in the water. For the examination of a seabed, the underwater device can be completely immersed in the water. The underwater device can be used to study marine and freshwater ecosystems. 
     The releasable connection between the first housing part and the second housing part is designed in a watertight manner. This prevents water from entering the cavity and damaging electrical consumers. The watertight connection ensures that there are no passages in a connecting area between the first housing part and the second housing part through which water can flow into the cavity. The releasable connection can have a screw connection. 
     Electrical consumers are components of the underwater device that have electronic components and can therefore be damaged if they come into contact with water, in particular condensation water, and/or the humidity of the air surrounding them is too high. 
     A hyperspectral camera is a camera that captures multispectral data in very narrow spectral bands of visible light, near infrared and mid infrared. Hyperspectral cameras thus allow high spectral resolution of object-specific signatures in more than 15, but generally in 30-200 contiguous channels, enabling documentation of a nearly continuous spectrum for each image element. 
     In a particular embodiment, the underwater device can have a colour camera for capturing images of the seabed. The colour camera can be arranged in the cavity and/or be an RGB camera. 
     The colour camera, especially RGB camera, is not a hyperspectral camera. The colour camera differs from the hyperspectral camera in that it has fewer channels than the hyperspectral camera, in particular exactly three channels. Accordingly, with a colour camera, the viewed object cannot be spectrally resolved as high as with a hyperspectral camera. The use of a colour camera and a hyperspectral camera offers the advantage that several images are captured of the same object, which is beneficial for image evaluation. 
     The colour camera and the hyperspectral camera can be arranged in a cavity section partially enclosed by the first housing part or the second housing part. Thus, tolerances of only one housing part have to be considered when arranging and mounting the hyperspectral camera and/or the colour camera. 
     The first housing part can have an opening in which a transparent plate, in particular a glass pane, is arranged in a watertight manner. The hyperspectral camera can be arranged in such a way that the image can be captured through the transparent plate. The colour camera can be arranged inside the cavity in the same way that images can be captured through the transparent plate. The hyperspectral camera and the RGB camera can be arranged entirely within the cavity. As a result, it is easy to ensure that the colour camera and/or hyperspectral camera are protected from coming into contact with water and that images of the seabed can be captured. 
     In a particular embodiment, a connecting direction for connecting the first housing part to the second housing part can be directed along a centre axis of the first housing part and/or the second housing part. Furthermore, the connecting direction can be perpendicular to an end face plane of the first housing part and/or the second housing part. The connection of the first housing part and the second housing part along the connecting direction offers the advantage that the connecting area to be sealed is small. Thus, sealing is merely required along an end face circumference of the first housing part and/or the second housing part. The end face plane can be an axial normal plane to the centre axis and/or parallel to a vertical plane. The vertical plane is perpendicular to a horizontal seabed. 
     For sealing, at least one seal can be arranged between the first housing part and the second housing part. The seal can be arranged on an end face area of the first and/or second housing part. As a result, the watertight connection between the first housing part and the second housing part can be realised in a simple manner. 
     After joining the two housing parts, the end face of the first housing part can be in contact with the second housing part and/or the end face of the second housing part can be in contact with the first housing part. 
     In a particular embodiment, the two housing parts can be connectable to one another by hand and/or releasable from one another by hand. The connection of the two housing parts to one another or the disconnection from one another is performed in a non-destructive manner. Thus, the underwater device can be easily assembled or disassembled. 
     Assembly or disassembly of the underwater device is particularly easy if the first housing part forms one half of the housing and the second housing part forms a second half of the housing of the underwater device. In this design, the underwater device has exactly two housing components, namely the two housing halves. The effort required to assemble or disassemble the underwater device is minimised with this design. 
     In a particular embodiment, the wall section of the first housing part and/or the second housing part can completely separate the cavity from the other cavity. This is advantageous because it cannot be ruled out that water can flow into the other cavity when the electrical energy storage device is replaced. A replacement of the electrical energy storage device will usually be performed on board of a ship. Depending on the sea state, it cannot be ruled out that the underwater device may come into contact with water. 
     However, with the underwater device according to the invention, the wall section prevents water from entering the cavity from the other cavity. As a result, the wall section prevents the electrical consumers located in the cavity, such as the cameras, control devices, etc., from coming into contact with water. Due to the watertight separation of the cavity from the other cavity, the electrical energy storage device can also be replaced on board of a ship with the underwater device according to the invention. 
     The underwater device can be designed in such a way that the wall section of the first housing part and/or the second housing part delimits both the cavity and the other cavity. This makes it possible to realise a particularly compact underwater device. One advantage of a compact underwater device is that it is easier to manoeuvre under water than large underwater devices. 
     In a particular embodiment, the electrical energy storage device can be designed in such a way that it can be inserted into the other cavity. This allows the electrical energy storage device to be easily inserted into the other cavity. In the same way, the electrical energy storage device can be pushed out of the other cavity. Therefore, in the underwater device, insertion of the electrical energy storage device into the other cavity or removal of the electrical energy storage device from the other cavity can be handled in a simple manner. 
     The electrical energy storage device can be designed to be modular, which further simplifies insertion and removal. The electrical energy storage device can have at least one battery. 
     When the electrical energy storage device is inserted into the other cavity, an electrical connection can be automatically established between the electrical energy storage device and the hyperspectral camera and/or another electrical consumer of the underwater device. The electrical energy storage device can have an electrical interface, such as a connector, which is coupled to another electrical interface of the first or second housing part to implement the electrical connection. This makes the installation of the electrical energy storage device particularly easy because the steps to be taken by the user are minimised. There can be an opening in the wall section through which electrical lines are routed. Electrical consumers of the underwater device can be electrically connected to the electrical energy storage device by means of the electrical lines. 
     The underwater device can be designed in such a way that an electrical line between the electrical energy storage device and the hyperspectral camera and/or between the electrical energy storage device and another electrical consumer runs exclusively within the first housing part and/or the second housing part. In doing so, the electrical line can run in such a way that it does not come into contact with water. This offers the advantage that, during the diving process, the danger is eliminated that, for example, the user unintentionally disconnects the electrical connection between the electrical energy storage device and the electrical consumer. 
     The other cavity can have a cavity cover by means of which the other cavity can be closed. The cavity cover can be attached to the first or second housing part. Furthermore, the cavity cover can be movable relative to the first or second housing part. 
     In a particular embodiment, there can be at least one rail-shaped touchdown device for placing on the seabed. At least one weight can be attached to the touchdown device. One part of the touchdown device can be fixed to the first housing part and another part of the rail can be fixed to the second housing part. The touchdown device can be designed in such a way that the weight can be positioned at different points on the rail. This makes it easy to adjust the centre of mass of the underwater device. Thus, the weight can be positioned on the rail in such a way that a centre of buoyancy of the underwater device and a centre of mass of the underwater device lie in an axial normal plane to the centre axis of the underwater device. This is a simple way to prevent the underwater device from rotating and the user from having to apply a force to prevent it from rotating. 
     The underwater device can have several touchdown devices, in particular exactly two touchdown devices. The touchdown devices can be arranged in parallel or at an angle to one another. Furthermore, the touchdown devices can protrude from the first and/or second housing part in such a way that the underwater device can be placed on the seabed by means of the touchdown devices. Thus, the underwater device does not need to have separate feet by means of which the underwater device can be placed on the seabed. 
     The underwater device can map the seabed based on the images captured. Compared to previous underwater devices, the use of the underwater device according to the invention enables a very precise examination of the seabed. 
     In a particular embodiment, the underwater device can be designed in such a way that it is manually controllable and/or operable and/or portable. This means that the underwater device is not controlled remotely by a ship, but solely by the diver. The underwater device can be designed without a propeller. This means that the underwater device is propelled solely by the diver. The underwater device thus does not have a drive motor to drive the underwater device. 
     In a particular embodiment, the first housing part and/or the second housing part can have another opening and a cover for closing the other opening in a watertight manner. One sensor of the underwater device and the other opening can be arranged in one plane. The plane can be an axial normal plane to the centre axis of the underwater device. 
     The cover can be made of a different material than the first housing part and/or the second housing part. The first housing part and/or the second housing part can be made of metal. However, metal prevents some measurement signals and/or data signals from reaching the sensor, such as a Global Navigation Satellite System (GNSS) sensor. Therefore, the cover has the advantage that such measurement signals and/or data signals can be received. Indeed, the other material of the cover can be designed to allow wireless communication between the sensor and a different communication means. In particular, the other material can be selected in such a way that it does not reflect radio data and thus enables the sensor to receive data. 
     The underwater device can have at least one handle for steering the underwater device. The handle can be attached to the first housing part and/or the second housing part. The handle allows the underwater device to be manoeuvred easily. 
     The first housing part and/or the second housing part can have an indentation facing away from the handle. The indentation and the handle are arranged in such a way that they are located in an axial normal plane to the centre axis of the underwater device. Since gloves are often worn under water, the indentation allows the handle to be placed close to the first housing part and/or the second housing part. The handle can be easily grasped by the user because there is sufficient space due to the indentation. 
     In a particular embodiment, the underwater device can have a valve that opens when a pressure in the cavity is too high. Alternatively, the valve can be opened by a user. In addition, there can be another valve that opens when the pressure in the other cavity is too high. Alternatively, the other valve can be opened by a user. As a result, excess pressure in the cavity and/or the other cavity can be easily relieved or prevented. 
     It is of particular advantage if the underwater device is a diver-operated underwater device. Diver-operated underwater device means a device that can be operated by a diver in or under water. This means that the diver can move the underwater device in or under the water and thus move it to the desired position to capture images of the desired area of the seabed. In addition, the diver can operate the underwater device in or under water, in particular enter corresponding commands to capture images of the seabed. 
     Alternatively, the underwater device can be an autonomous underwater vehicle. With this design, the underwater device does not need to be moved by the diver to capture images of the seabed. The underwater vehicle can be controlled autonomously. 
     Alternatively, the underwater device can be a cable-guided underwater vehicle (remotely operated vehicle). With this design, the underwater device does not need to be moved by the diver to capture images of the seabed. The underwater vehicle can be controlled by a person on the ship. 
    
    
     
       The subject matter of the invention is shown schematically in the figures, wherein elements that are the same or have the same effect are mostly provided with the same reference symbols. In the figures: 
         FIG. 1  shows a side section view of an underwater device according to the invention without electrical consumers, 
         FIG. 2  shows a side section view of the underwater device according to the invention with electrical consumers, 
         FIG. 3  shows an exploded view of the underwater device according to the invention, 
         FIG. 4  shows a perspective view of the underwater device according to the invention, 
         FIG. 5  shows a front view of the underwater device according to the invention. 
     
    
    
     The underwater device  1  shown in  FIG. 1  is a diver-operated underwater device. The underwater device  1  can alternatively be an autonomous underwater vehicle or a cable-guided underwater vehicle. 
     The underwater device  1  has a first housing part  3  and a second housing part  4 , which is releasably connected to the first housing part  3  in a watertight manner. The first and second housing parts  3 ,  4  enclose a cavity  5 . In addition, the second housing part  4  has another cavity  7  which is completely separated from the cavity  5  in a watertight manner by a wall section  13  of the second housing part  4 . The other cavity  7  is closed by a cavity cover  14 . The cavity cover  14  is again releasably connected to the second housing part  4 . In the embodiment shown in  FIG. 1 , there are no electrical consumers either in the cavity  5  or in the other cavity  7 . 
     The first housing part  3  has an opening  10 . A transparent plate  11  in the form of a glass pane is arranged in the opening  10 . The transparent plate  11  is designed in such a way and connected to the first housing part  3  in such a way that water is prevented from entering the cavity  5  through the opening  10 . 
     The first housing part  3  has a recess  32  at its end facing away from the second housing part  4 . The recess  32  is used to accommodate sensors not shown in the figures. Alternatively or in addition, a communication means for sending and/or receiving data can be arranged in the recess  32 . Using the communication means, a data-transmitting connection can be established with, for example, another communication means located on a ship. 
       FIG. 2  shows a side section view of the underwater device  1  according to the invention with electrical consumers. The underwater device  1  has a hyperspectral camera  2  and a colour camera  8  arranged in the cavity  5 . Furthermore, the underwater device  1  has an electrical energy storage device  6  for supplying electrical energy to the hyperspectral camera  2  and the colour camera  8 . In addition, the electrical energy storage device  6  supplies further electrical consumers of the underwater device  1 . The electrical energy storage device  6  is arranged in the other cavity  7  and can have several batteries. 
     In the figures, the electrical lines between the electrical energy storage device  6  and the colour camera  8  and the hyperspectral camera  2  and the other electrical consumers (not shown) are not shown. However, they run inside the first housing part  3  and/or the second housing part  4 . In particular, the electrical lines are arranged in such a way that they do not come into contact with water and thus do not run outside the first housing part  3  and the second housing part  4 . 
     The colour camera  8  and the hyperspectral camera  2  are arranged in the cavity  5  in such a way that they can each capture images through the transparent plate  11 . In addition, the colour camera  8  and the hyperspectral camera  2  are arranged in a cavity section  9  defined by the first housing part  3 . The cavity  5  is composed of the cavity section  9  defined by the first housing part  3  and another cavity section  33  defined by the second housing part  4 . 
     The underwater device  1  has another opening  16  in the second housing part  4 . The other opening  16  is closed by a cover  17 . The cover  17  is made of a different material than the first housing part  3  and the second housing part  4 . A sensor  18 , in particular a GNSS sensor, is arranged below the cover  17 . In this case, the sensor  18  is arranged in such a way that it and the other opening  16  are arranged in one plane, in particular an axial normal plane to a centre axis M of the underwater device  1 . 
     Furthermore, the underwater device  1  has a display device  21  by means of which, for example, images captured by the cameras are displayed to a user. Furthermore, operating states of the underwater device  1  can be displayed to the user via the display device  21 . The data obtained from the cameras  2 ,  8  and/or other electrical consumers can be processed by a control device  23  arranged in the cavity  5 . The display device  21  and/or the electrical consumers and/or the control device  23  are arranged in the cavity  5 . 
     The underwater device  1  also has a measuring device  22 , such as a Doppler Velocity Log, by means of which the direction of the underwater device  1  and speed over ground can be measured. The measuring device  22  protrudes from an opening of the first housing part  3  and the second housing part  4 . In this case, the measuring device  22  is designed in such a way and/or connected to the first housing part  3  and the second housing part  4  in such a way that no water can flow into the cavity  5  of the underwater device  1 . 
     The underwater device  1  further has a position determination element  29  for determining the position of the underwater device  1  under water. The position determining element  29  can be an ultra short baseline (USBL) device and can be arranged in a recess of an outer side of the first housing part  3 . 
     Furthermore, the underwater device  1  has an energy distribution unit  30  arranged inside the cavity  5 . The energy distribution unit  30  is used to distribute the electrical energy from the electrical energy storage device to the electrical consumers of the underwater device  1 . In this regard, the energy distribution unit  30  can disconnect the electrical connection between the electrical energy storage device and the electrical consumer if, for example, a hazardous condition, such as water entering the cavity  5 , is detected. 
     Furthermore, the underwater device  1  has a detection means  31 , such as an IMU sensor (inertial measurement unit) for detecting a movement of the underwater device  1 . The detection means  31  is used for navigation of the underwater device  1  and is arranged in the cavity  5 . 
       FIG. 3  shows an exploded view of the underwater device  1  according to the invention. In order to connect the two housing parts  3 ,  4 , the first housing part  3  and/or the second housing part  4  are moved towards one another in the connecting direction V along the centre axis M of the underwater device  1 . The connecting direction V of the first housing part  3  is opposite to the connecting direction V of the second housing part  4 . Both connecting directions V run perpendicular to an end face plane of the first housing part  3  and/or the second housing part  4 . 
     The first housing part  3  and the second housing part  4  are connected to one another in a connecting area  27 . The connecting area  27  runs in the circumferential direction of an end face  24  of the first housing part and/or an end face  25  of the second housing part  4 . In particular, after connecting the first housing part  3  to the second housing part  4 , the end face  24  of the first housing part  3  is in contact with the second housing part  4  and the end face  25  of the second housing part  4  is in contact with the first housing part  3 . Seals  12  are arranged between the first housing part  3  and the second housing part  4  for the watertight connection of the first housing part  3  with the second housing part  4 . 
     The first housing part  3  and the second housing part  4  can again be releasably connected to one another. The releasable connection can, for example, be realised by screws.  FIG. 3  shows a hole  26  for receiving a screw. 
       FIG. 4  shows a perspective view of the underwater device  1  according to the invention and  FIG. 5  shows a front view of the underwater device  1  according to the invention. The underwater device  1  has two rail-shaped touchdown devices  15  which are arranged opposite one another with respect to the first housing part  3  and the second housing part  4  and are used to place the underwater device  1  on a seabed. One part of the touchdown device  15  is firmly connected to the first housing part  3  and another part of the touchdown device  15  is firmly connected to the second housing part  4 . 
     The touchdown devices  15  are designed in such a way that at least one weight can be positioned at different points on them. By positioning the weight, the centre of mass of the underwater device  1  can be adjusted. In particular, the weight can be arranged in such a way that the centre of mass and the centre of buoyancy of the underwater device  1  are arranged in an axial normal plane to the centre axis M. 
     The touchdown devices  15  protrude from the first housing part  3  and the second housing part  4 . They protrude further than the measuring device  22 , which is not shown in  FIGS. 4 and 5 . This prevents the measuring device  22  from coming into contact with the seabed when the underwater device  1  is placed on the seabed. 
     The underwater device  1  also has three handles. A handle  28  is arranged on each side of the underwater device  1 . In addition, another handle  19  is arranged on an upper side of the underwater device  1 . On each of the two sides of the underwater device  1 , there is an indentation  20  in the first housing part  3  and the second housing part  4 . 
     The indentations  20  allow the user to grip around the handles  28  without being obstructed by the first housing part  3  and/or the second housing part  4 . The indentations  20  and the laterally positioned handles  28  are arranged in such a way that an axis normal plane to the centre axis M has at least one handle and the indentation  20 . Each of the two indentations  20  extends almost over the entire length of the underwater device  1 . In this regard, the indentations  20  can extend and be designed in such a way as to facilitate the operation of buttons  34 . 
     Commands for the underwater device  1  can be entered by means of the buttons  34 . 
     LIST OF REFERENCE SIGNS 
     
         
           1  Underwater device 
           2  Hyperspectral camera 
           3  First housing part 
           4  Second housing part 
           5  Cavity 
           6  Electrical energy storage device 
           7  Other cavity 
           8  Colour camera 
           9  Cavity section 
           10  Opening 
           11  Transparent plate 
           12  Seal 
           13  Wall section 
           14  Cavity cover 
           15  Rail-shaped touchdown device 
           16  Other opening 
           17  Cover 
           18  Sensor 
           19  Other handle 
           20  Indentation 
           21  Display device 
           22  Measuring device 
           23  Control device 
           24  End face of the first housing part 
           25  End face of the second housing part 
           26  Hole 
           27  Connecting area 
           28  Handle 
           29  Position determination element 
           30  Energy distribution unit 
           31  Detection means 
           32  Recess 
           33  Other cavity section 
           34  Button 
         V Connecting direction