Water object detection system and vessel

Abstract

To provide a water area object detection system and a vessel capable of improving positional accuracy in a water area map created based on an image imaged by a plurality of imaging units.SOLUTION: A water area object detection system 103 includes: a first imaging unit 1a provided on a hull 101 for imaging an image of an object O in the periphery of a hull 101; a second imaging unit 1b provided on the hull 101 with approximately matching an imaging direction with the first imaging unit 1a for imaging the image of the object O in the periphery of the hull 101; and a control unit 3 for carrying out control for creating a water area map M of the periphery of the hull 101 based on an image imaged by the first imaging unit 1a and the second imaging unit 1b, wherein the second imaging unit 1b is arranged in a position deviated in a vertical direction to the first imaging unit 1a as well as being arranged in a position deviated in the imaging direction to the first imaging unit 1a so as not to overlap with the first imaging unit 1a in the imaging direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an underwater object detection system and a ship, and more particularly to a water area object detection system and a ship that are provided on a hull and have a plurality of imaging units that capture images of the periphery of the hull. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a water area object detection system and a ship that are provided with a plurality of imaging units that are mounted on a hull and capture images of the periphery of the hull (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses an automatic ship docking system equipped with multiple imaging units for imaging the periphery of the ship. The multiple imaging units of the automatic ship docking system are arranged side-by-side on the ship. The multiple imaging units are configured to capture an image of a single imaging target, such as a wharf, with the multiple imaging units and calculate the distance to the imaging target by the principle of triangulation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-180949 A Summary of the Invention [Problem to be solved by the invention]

[0005] Although not specified in the above Patent Document 1, a technique has been known in the past to create a hull periphery map by calculating the distance to a feature point included in an image target (objects around the hull) using two imaging units. In the above technique, when creating a hull periphery map, it is known to reduce the load of image calculation processing by using an epipolar constraint, which is a geometric constraint that all points located between one imaging unit and a feature point are necessarily present on an epipolar line, which is a line obtained by projecting a line connecting one imaging unit and a feature point onto the image of the other imaging unit. In addition, in the above technique, it is known that when performing image calculation processing using the epipolar constraint, the greater the variance of the angles of the acquired multiple epipolar lines (the greater the difference in angles), the smaller the measurement error of the distance to the feature point, while the smaller the variance of the angles of the multiple epipolar lines (the smaller the difference in angles), the larger the measurement error of the distance to the feature point and the lower the positional accuracy of the periphery map.

[0006] When such a technique is applied to the ship automatic docking system of Patent Document 1, since multiple imaging units are arranged side by side on the ship's hull, many epipolar lines extending in the horizontal direction, which is the direction in which the imaging units are arranged, are acquired. In other words, the variance of the angles of the multiple epipolar lines (the difference in angles between the multiple epipolar lines) becomes relatively small, and the positional accuracy of the surrounding map becomes low. For this reason, there has been a demand for creating a surrounding map with higher positional accuracy based on images captured by multiple imaging units.

[0007] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an water area object detection system and a ship that can improve the positional accuracy of a water area map created based on images captured by multiple imaging units. [Means for solving the problem]

[0008] In order to solve the above problems, a water area object detection system according to a first aspect of the present invention includes a first imaging unit that is provided on a hull and captures images of objects around the hull, a second imaging unit that is provided on the hull so that its imaging direction is substantially the same as that of the first imaging unit and captures images of objects around the hull, and based on the images captured by the first imaging unit and the second imaging unit, a two-dimensional map displaying a schematic model of the hull and a predetermined angle of view indicating the range captured by the first imaging unit and the second imaging unit; The distance to the object captured by the first and second imaging units is measured, and the object around the hull is detected. The range in which and a control unit that performs control to create a water area map showing the water area, and the second imaging unit is disposed at a position shifted in the up and down direction relative to the first imaging unit, and is disposed at a position shifted in the imaging direction relative to the first imaging unit so as not to overlap with the first imaging unit in the imaging direction, and the control unit: A schematic model of the ship's hull is displayed on the display. Based on the water body map, On the water map object The range in which Set a route to automatically move around and avoid and automatically move the ship along the route on the water map. The control unit is configured to:

[0009] In the water area object detection system according to the first aspect, as described above, a first imaging unit and a second imaging unit are provided to capture images of objects around the ship, and the second imaging unit is disposed at a position offset in the vertical direction from the first imaging unit, and the second imaging unit is disposed at a position offset in the imaging direction from the first imaging unit so as not to overlap with the first imaging unit in the imaging direction. Here, in a technology for creating a water area map using two imaging units having the same imaging direction, when the two imaging units are offset in the imaging direction, the variance of the angles of the multiple epipolar lines becomes larger (the difference in angles becomes larger) compared to when the two imaging units are offset only in a direction perpendicular to the imaging direction, such as the horizontal direction or the vertical direction. Therefore, with the above-mentioned configuration, the second imaging unit can be disposed at a relatively large offset position so as not to overlap with the first imaging unit in the imaging direction, so that the variance of the angles of the multiple epipolar lines becomes larger. As a result, the positional accuracy of the water area map created based on the images captured by the first imaging unit and the second imaging unit can be improved. Furthermore, by disposing the second imaging section at a position vertically shifted from the first imaging section, it is possible to prevent the imaging range directly in front of the second imaging section from being limited by the first imaging section.

[0010] In the water area object detection system according to the first aspect, the first and second imaging units are preferably configured to capture an image of the rear of the hull in the imaging direction, and the second imaging unit is disposed in a position shifted upward from the first imaging unit and in a position shifted forward from the first imaging unit. With this configuration, the first imaging unit is disposed below the second imaging unit in the imaging direction, so that it is possible to prevent the first imaging unit and a configuration for installing the first imaging unit from being reflected in the image captured by the second imaging unit.

[0011] In this case, the first and second imaging units are preferably provided at the stern and roof of the hull, respectively. With this configuration, the first and second imaging units can be easily arranged by utilizing the existing stern and roof so that the first imaging unit is located below and rearward in the imaging direction of the second imaging unit.

[0012] In the water area object detection system according to the first aspect, the second imaging unit is preferably arranged at a position where the first imaging unit falls within the imaging range of the second imaging unit. With this configuration, it is possible to prevent the second imaging unit from being arranged so that the first imaging unit does not fall within the imaging range of the second imaging unit. In other words, it is possible to prevent the second imaging unit from approaching an arrangement where the second imaging unit is arranged in a horizontal or vertical direction perpendicular to the imaging direction with respect to the first imaging unit. This makes it possible to further improve the positional accuracy of the water area map created based on images captured by the first imaging unit and the second imaging unit.

[0013] In this case, the installation angle of the first imaging unit relative to the second imaging unit with respect to the horizontal plane as a reference is preferably 50 degrees or less. With this configuration, the installation angle of the first imaging unit relative to the second imaging unit with respect to the horizontal plane as a reference is limited to 50 degrees or less, so that it is possible to prevent the second imaging unit from being positioned directly above the first imaging unit due to the installation angle becoming too large. In other words, it is possible to prevent the second imaging unit from being positioned in a direction perpendicular to the imaging direction of the first imaging unit, such as the lateral direction or vertical direction (directly above), so that it is possible to prevent the variance of the angles of the multiple epipolar lines from becoming small. This makes it possible to further improve the positional accuracy of the water area map created based on the images captured by the first imaging unit and the second imaging unit.

[0014] In the water area object detection system according to the first aspect, the control unit is preferably configured to automatically move the hull toward the shore structure, which is the object imaged by the first imaging unit and the second imaging unit, thereby automatically docking the hull. With this configuration, the hull can be easily docked on the shore structure.

[0015] In the water area object detection system according to the first aspect, the second imaging unit is preferably disposed relative to the first imaging unit such that, when the distance to the object imaged by the first imaging unit and the second imaging unit is 10 m or less, the target error of the first imaging unit and the second imaging unit is 10 cm or less. With this configuration, the target error of the first imaging unit and the second imaging unit can be kept small, thereby further improving the positional accuracy of the water area map created based on the images imaged by the first imaging unit and the second imaging unit.

[0016] In the water area object detection system according to the first aspect, the control unit is preferably configured to create a two-dimensional water area map that spreads in a horizontal direction perpendicular to the up-down direction in which the first imaging unit and the second imaging unit are arranged with a shift from each other. With this configuration, the processing load on the control unit can be reduced compared to a case in which a three-dimensional water area map that takes into account the up-down direction (height direction) is created.

[0017] In the water area object detection system according to the first aspect, the distance between the first imaging unit and the second imaging unit is preferably 2.0 m or less. With this configuration, the first imaging unit and the second imaging unit are disposed relatively close to each other, so that the first imaging unit and the second imaging unit can be easily installed on a relatively small vessel.

[0018] In the water area object detection system according to the first aspect, the control unit is preferably configured to detect feature points corresponding to objects in the images based on the images captured by the first and second imaging units, and create a water area map that provides an object existence range in which the object may exist around the feature points. With this configuration, the object existence range that the ship should avoid is displayed on the water area map, making it easy to grasp objects around the hull.

[0019] A water area object detection system according to a second aspect of the present invention includes a first imaging unit that is provided on a hull and captures an image of the periphery of the hull, a second imaging unit that is configured separately from the first imaging unit and is provided on the hull so that its imaging direction is substantially the same as that of the first imaging unit and captures an image of the periphery of the hull, and based on images captured by the first imaging unit and the second imaging unit, a two-dimensional map displaying a schematic model of the hull and a predetermined angle of view indicating the range captured by the first imaging unit and the second imaging unit; The distance to the object captured by the first and second imaging units is measured, and the object around the hull is detected. The range in which and a control unit that controls the creation of a water area map showing the water area, and the second imaging unit is disposed at a position shifted in the vertical direction relative to the first imaging unit and at a position shifted in the imaging direction relative to the first imaging unit, and the control unit: A schematic model of the ship's hull is displayed on the display. Based on the water body map, On the water map object The range in which Set a route to automatically move around and avoid and automatically move the ship along the route on the water map. The control unit is configured to:

[0020] In the water area object detection system according to the second aspect, as described above, a first imaging unit and a second imaging unit are provided to capture images of objects around the ship, and the second imaging unit is disposed at a position offset in the vertical direction from the first imaging unit, and the second imaging unit is disposed at a position offset in the imaging direction from the first imaging unit. Here, in a technology for creating a water area map using two imaging units having the same imaging direction, when the two imaging units are offset in the imaging direction, the variance of the angles of the multiple epipolar lines becomes larger (the difference in angles becomes larger) compared to when the two imaging units are offset only in a direction perpendicular to the imaging direction, such as the lateral direction or the vertical direction. Therefore, with the above-mentioned configuration, the second imaging unit can be disposed at a position offset in the imaging direction from the first imaging unit so that the variance of the angles of the multiple epipolar lines becomes larger. As a result, the positional accuracy of the water area map created based on the images captured by the first imaging unit and the second imaging unit can be improved. In addition, by disposing the second imaging unit at a position shifted vertically from the first imaging unit, the imaging range directly in front of the second imaging unit can be prevented from being limited by the first imaging unit. In addition, since the first imaging unit and the second imaging unit are separate, their positions can be freely adjusted.

[0021] A marine vessel according to a third aspect of the present invention includes a hull and a water area object detection system provided on the hull. The water area object detection system includes a first imaging unit provided on the hull and configured to capture images of objects around the hull, a second imaging unit provided on the hull so as to have an imaging direction substantially aligned with that of the first imaging unit and configured to capture images of objects around the hull, and based on images captured by the first imaging unit and the second imaging unit, a two-dimensional map displaying a schematic model of the hull and a predetermined angle of view indicating the range captured by the first imaging unit and the second imaging unit; The distance to the object captured by the first and second imaging units is measured, and the object around the hull is detected. The range in which and a control unit that performs control to create a water area map showing the water area, the second imaging unit being disposed at a position shifted in the up and down direction relative to the first imaging unit, and being disposed at a position shifted in the imaging direction relative to the first imaging unit so as not to overlap with the first imaging unit in the imaging direction, and the control unit: A schematic model of the ship's hull is displayed on the display. Based on the water body map, On the water map object The range in which Set a route to automatically move around and avoid and automatically move the ship along the route on the water map. The control unit is configured to:

[0022] In the ship according to the third aspect, as described above, a first imaging unit and a second imaging unit are provided to capture images of objects around the ship, and the second imaging unit is disposed at a position offset in the vertical direction from the first imaging unit, and the second imaging unit is disposed at a position offset in the imaging direction from the first imaging unit so as not to overlap with the first imaging unit in the imaging direction. Here, in a technology for creating a water area map using two imaging units having the same imaging direction, when the two imaging units are offset in the imaging direction, the variance of the angles of the multiple epipolar lines becomes larger (the difference in angles becomes larger) compared to when the two imaging units are offset only in a direction perpendicular to the imaging direction, such as the horizontal direction or the vertical direction. Therefore, with the above-mentioned configuration, the second imaging unit can be disposed at a relatively large offset position so as not to overlap with the first imaging unit in the imaging direction, so that the variance of the angles of the multiple epipolar lines becomes larger. As a result, a ship can be provided that can improve the positional accuracy of a water area map created based on images captured by the first imaging unit and the second imaging unit. Furthermore, by disposing the second imaging section at a position vertically shifted from the first imaging section, it is possible to prevent the imaging range directly in front of the second imaging section from being limited by the first imaging section.

[0023] In the ship according to the third aspect, the overall length of the hull is preferably 20 m or less. With this configuration, it is possible to provide a relatively small ship that can improve the positional accuracy of a water area map created based on images captured by the first imaging unit and the second imaging unit.

[0024] In the marine vessel according to the third aspect, the first and second imaging units are preferably configured to capture an image of the rear of the hull in the imaging direction, and the second imaging unit is disposed in a position shifted upward relative to the first imaging unit and in a position shifted forward relative to the first imaging unit. With this configuration, the first imaging unit is disposed below the second imaging unit in the imaging direction, making it possible to prevent the first imaging unit and a configuration for installing the first imaging unit from being captured in an image captured by the second imaging unit.

[0025] In this case, the first and second imaging units are preferably provided at the stern and roof of the hull, respectively. With this configuration, the first and second imaging units can be easily arranged by utilizing the existing stern and roof so that the first imaging unit is located below and rearward in the imaging direction of the second imaging unit.

[0026] In the marine vessel according to the third aspect, the second imaging unit is preferably arranged at a position where the first imaging unit falls within the imaging range of the second imaging unit. With this configuration, it is possible to prevent the second imaging unit from being arranged so that the first imaging unit does not fall within the imaging range of the second imaging unit. In other words, it is possible to prevent the second imaging unit from approaching an arrangement where the second imaging unit is arranged in a horizontal or vertical direction perpendicular to the imaging direction with respect to the first imaging unit. This makes it possible to further improve the positional accuracy of the water area map created based on images captured by the first imaging unit and the second imaging unit.

[0027] In this case, the installation angle of the first imaging unit relative to the second imaging unit with respect to the horizontal plane as a reference is preferably 50 degrees or less. With this configuration, the installation angle of the first imaging unit relative to the second imaging unit with respect to the horizontal plane as a reference is limited to 50 degrees or less, so that it is possible to prevent the second imaging unit from being positioned directly above the first imaging unit due to the installation angle becoming too large. In other words, it is possible to prevent the second imaging unit from being positioned in a direction perpendicular to the imaging direction of the first imaging unit, such as the lateral direction or vertical direction (directly above), so that it is possible to prevent the variance of the angles of the multiple epipolar lines from becoming small. This makes it possible to further improve the positional accuracy of the water area map created based on the images captured by the first imaging unit and the second imaging unit.

[0028] In the marine vessel according to the third aspect, the control unit is preferably configured to automatically move the hull toward the shore structure that is the object imaged by the first imaging unit and the second imaging unit, thereby automatically docking the hull. With this configuration, the hull can be easily docked on the shore structure.

[0029] In the ship according to the third aspect, the second imaging unit is preferably disposed with respect to the first imaging unit such that, when the distance to an object imaged by the first imaging unit and the second imaging unit is 10 m or less, the target error of the first imaging unit and the second imaging unit is 10 cm or less. With this configuration, the target error of the first imaging unit and the second imaging unit can be kept small, thereby further improving the positional accuracy of the water area map created based on the images imaged by the first imaging unit and the second imaging unit.

[0030] In the marine vessel according to the third aspect, the control unit is preferably configured to create a two-dimensional water area map that extends in a horizontal direction perpendicular to the up-down direction in which the first imaging unit and the second imaging unit are arranged offset from each other. With this configuration, the processing load on the control unit can be reduced compared to creating a three-dimensional water area map that takes into account the up-down direction (height direction). Effect of the Invention

[0031] According to the present invention, as described above, it is possible to improve the positional accuracy of a water area map created based on images captured by a plurality of imaging units. [Brief description of the drawings]

[0032] [Figure 1] 1 is a side view showing a vessel equipped with a water area object detection system according to an embodiment. [Diagram 2] FIG. 2 is a plan view for explaining docking of a ship to a shore structure according to an embodiment. [Diagram 3] FIG. 2 illustrates a water body map created by the water body object detection system according to an embodiment. [Figure 4] 1 is a schematic diagram for explaining the size of an object existence range on a water area map created by a water area object detection system according to an embodiment. FIG. [Diagram 5] 4A to 4C are diagrams for explaining triangulation performed by a first imaging unit and a second imaging unit of the water area object detection system according to the embodiment. [Figure 6] 13 is a graph showing the relationship between the installation angle (θ) of the first imaging unit with respect to the second imaging unit with the horizontal plane as the reference, and the standard deviation of the angle of the epipolar line. [Figure 7] 13 is a diagram for explaining an embodiment in which an epipolar line is shown in an image of a second imaging unit when the first imaging unit and the second imaging unit are shifted in the imaging direction. FIG. [Figure 8] FIG. 13 is a diagram for explaining a comparative example in which an epipolar line is displayed in an image of a second imaging unit when the first imaging unit and the second imaging unit are arranged side by side. [Figure 9] 13 is a graph showing the relationship between the installation angle (θ) of the first imaging unit with respect to the second imaging unit with respect to the horizontal plane, and the distance (D) between the first imaging unit and the second imaging unit. [Figure 10] 11 is a diagram for explaining the arrangement of a first imaging section relative to a second imaging section in Examples (2 and 3) and Comparative Examples (1, 4 to 7). FIG. [Figure 11] 13 is a graph showing a change in relative orientation between captured images when a first imaging unit and a second imaging unit are disposed at predetermined positions and a plurality of images are captured. [Figure 12] 13 is a graph showing the relationship between the arrangement of the first imaging unit with respect to the second imaging unit and the standard change in error in relative attitude between captured images. [Figure 13] 13 is a graph showing the relationship between the arrangement of the first imaging unit with respect to the second imaging unit and the variance of the angle of the epipolar line. [Figure 14] 13 is a graph showing the relationship between the variance of the angle of the epipolar line and the error in the relative orientation between captured images. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, an embodiment will be described with reference to the drawings.

[0034] [Embodiment] (Overall configuration of the ship) The configuration of a ship 100 equipped with a water area object detection system 103 according to an embodiment will be described with reference to FIGS.

[0035] In the figure, FWD indicates the forward direction of the ship 100 (forward with respect to the hull 101), and BWD indicates the reverse direction of the ship 100 (rearward with respect to the hull 101). BWD is also the imaging direction of the first imaging unit 1a and the second imaging unit 1b. A center line α1 of the imaging range A1 of the first imaging unit 1a and a center line α2 of the imaging range A2 of the second imaging unit 1b are parallel to the BWD. In addition, the center lines α1 and α2 are parallel to a center line β (see FIG. 2) in the left-right direction of the hull 101.

[0036] Furthermore, L in the drawing indicates the port direction of the ship 100 (leftward based on the hull 101), and R indicates the starboard direction of the ship 100 (rightward based on the hull 101).

[0037] In addition, the Z direction in the figure indicates the up-down direction, the Z1 direction indicates the upward direction, and the Z2 direction indicates the downward direction.

[0038] 1, a ship 100 includes a hull 101, a ship propulsion device 102 provided on the hull 101, and a water area object detection system 103 provided on the hull 101. The water area object detection system 103 includes a first imaging unit 1a and a second imaging unit 1b.

[0039] The boat propulsion device 102 is attached rearward to the stern (transom) T of the hull 101. That is, in this embodiment, the boat propulsion device 102 is configured as an outboard motor, and the boat 100 is configured as an outboard motor boat.

[0040] The overall length (length in the fore-aft direction) L10 of the hull 101 shown in Fig. 2 is 20 m (approximately 65 feet) or less, and is relatively small. As one example, the hull 101 is a small vessel with an overall length L10 of approximately 8.7 m (approximately 28 feet), and is a type of hull that is docked with the shore structure O1 located behind the hull 101, not to the left. Also, as one example, the width L11 of the hull 101 is approximately 2.5 m.

[0041] The water area object detection system 103 (control unit 3) shown in Fig. 1 is configured to perform control to create a two-dimensional water area map M (see Fig. 3) that extends in the horizontal direction around the hull 101, while estimating the self-position of the hull 101 in the water area map M. The two-dimensional water area map M is a map that extends in the horizontal direction perpendicular to the up-down direction (Z direction) in which the first imaging unit 1a and the second imaging unit 1b are arranged with a mutual offset.

[0042] As one example, the above-described control (control for estimating the self-position of the hull 101 on the water area map M while creating the water area map M) is realized by a means called SLAM (Simultaneous Localization And Mapping).

[0043] SLAM is a technology that uses images from a camera installed on a mobile device to simultaneously create an environmental map of the mobile device's surroundings and estimate the mobile device's own position on the environmental map. Unlike self-position estimation on a map using GPS (Global Positioning System), SLAM estimation of the mobile device's own position can be performed even in environments such as indoors where GPS cannot be used.

[0044] In addition, SLAM makes it possible for the mobile device to move around surrounding objects to avoid colliding with them, and also makes it possible for the mobile device to move along the optimal route without overlapping routes.

[0045] There are two types of SLAM: passive SLAM (such as so-called Visual SLAM), which is performed by capturing images of surrounding objects using an image sensor such as a camera, and active SLAM (such as so-called LiDAR SLAM), which is performed by irradiating a laser beam from a laser device onto surrounding objects and detecting the reflected laser beam. The water area object detection system 103 of this embodiment performs control using a means similar to the former passive SLAM.

[0046] As shown in Figures 3 and 4, the ship 100 is configured to be able to control the ship 100 to automatically move along a travel route r while avoiding obstacles (objects O) using a water area map M created using a water area object detection system 103, and to control the ship 101 to automatically dock at a shore structure O1 (see Figure 2) such as a floating pier.

[0047] Furthermore, not only when the ship 100 moves automatically, but also when the user manually steers the ship 100, the water area map M can be used as a means for grasping the position of an obstacle (object O). In other words, the water area map M is a so-called cost map for indicating the positions of obstacles (object O) that exist around the ship 100.

[0048] (Configuration of Water Object Detection System) 1, the water area object detection system 103 includes a first imaging unit 1a, a second imaging unit 1b, a display unit 2, and a control unit 3. The first imaging unit 1a, the second imaging unit 1b, the display unit 2, and the control unit 3 are provided on a hull 101.

[0049] As shown in FIG. 4, the water area object detection system 103 (control unit 3) is configured to control the creation of a water area map M that includes an object existence range F1 around the feature point F that includes the possibility that the object O may exist, by detecting a feature point F corresponding to an object O in the image together with the distance to the feature point F based on the images captured by the first imaging unit 1a and the second imaging unit 1b.

[0050] (Configuration of the "imaging unit" of the water area object detection system) The first imaging unit 1a and the second imaging unit 1b shown in FIG. 1 are configured to capture images of the periphery of the hull 101. The first imaging unit 1a and the second imaging unit 1b are configured with monocular cameras having the same structure. In other words, the second imaging unit 1b is configured separately from the first imaging unit 1a. The first imaging unit 1a and the second imaging unit 1b have imaging elements such as a CCD sensor or a CMOS sensor. The first imaging unit 1a and the second imaging unit 1b are disposed on a center line β (see FIG. 2) in the left-right direction of the hull 101 in a plan view.

[0051] The first imaging unit 1a is provided at the stern (transom) T of the hull 101. The second imaging unit 1b is provided at the roof R of the hull 101.

[0052] The second imaging unit 1b is provided on the hull 101 so that the imaging direction is substantially the same as that of the first imaging unit 1a. In detail, the first imaging unit 1a and the second imaging unit 1b are configured to capture images of the rear (BWD) of the hull 101 as the imaging direction.

[0053] The second imaging section 1b is disposed at a position shifted in the up-down direction with respect to the first imaging section 1a, and is disposed at a position shifted in the imaging direction with respect to the first imaging section 1a so as not to overlap with the first imaging section 1a in the imaging direction. In detail, the second imaging section 1b is disposed at a position shifted upward with respect to the first imaging section 1a, and is disposed at a position shifted forward with respect to the first imaging section 1a. The rear end (end on the first imaging section 1a side) of the second imaging section 1b is disposed forward of the front end (end on the second imaging section 1b side) of the first imaging section 1a. In this way, the second imaging section 1b is disposed at a position shifted upward with respect to the first imaging section 1a, so that the range directly in front of the imaging range A2 (center of the image) of the second imaging section 1b is not limited by the first imaging section 1a.

[0054] The second imaging unit 1b is disposed at a position where the first imaging unit 1a fits within the imaging range A2 of the second imaging unit 1b. That is, the second imaging unit 1b is disposed at a position where the first imaging unit 1a is reflected on the lower side of the image captured by the second imaging unit 1b.

[0055] Moreover, the installation angle θ (see FIG. 5) of the first imaging unit 1a with respect to the second imaging unit 1b with respect to the horizontal plane as a reference is 50 degrees or less. As an example, the installation angle θ of the first imaging unit 1a with respect to the second imaging unit 1b with respect to the horizontal plane as a reference is 30 degrees. Here, from the viewpoint of the epipolar constraint, which is a geometric constraint, it is known that the smaller the installation angle θ, the larger the variance of the angles of the multiple epipolar lines obtained, and the smaller the measurement error of the distance to the feature point, resulting in higher positional accuracy of the water area map.

[0056] As an example, FIG. 6 shows the results of acquiring multiple epipolar lines for each imaging unit arrangement in which the horizontal distance L1 between the first imaging unit 1a and the second imaging unit 1b shown in FIG. 5 is fixed and the installation angle θ of the first imaging unit 1a relative to the second imaging unit 1b based on the horizontal plane is changed from 10 degrees to 90 degrees, and calculating the standard deviation [rad] of the angles of the multiple epipolar lines. The smaller the installation angle θ, the smaller the standard deviation of the angles of the epipolar lines. In the embodiment, the installation angle θ is 50 degrees or less and the standard deviation is larger than 0.3. Note that the case in which the installation angle θ is 60 to 90 degrees shown in FIG. 6 is a comparative example.

[0057] Further, the distance D between the first imaging unit 1a and the second imaging unit 1b is 2.0 m or less. As an example, the distance D between the first imaging unit 1a and the second imaging unit 1b is 1.5 m. The range of the distance D being 2.0 m or less takes into consideration a configuration in which the overall length L10 (see FIG. 2) of the hull 101 is 20 m (approximately 65 feet) or less.

[0058] FIG. 7 shows an example of the present invention in which epipolar lines are shown in an image of the second imaging unit 1b when the distance D between the first imaging unit 1a and the second imaging unit 1b is 1.5 m and the installation angle θ of the first imaging unit 1a with respect to the second imaging unit 1b based on the horizontal plane is 30 degrees. FIG. 8 shows a comparative example in which epipolar lines are shown in an image of the second imaging unit when the first imaging unit and the second imaging unit are arranged side by side. In the image of FIG. 7, multiple epipolar lines extend radially. In the image of FIG. 8, multiple epipolar lines extend in the left-right direction.

[0059] The water area object detection system 103 (control unit 3) is configured to use the first imaging unit 1a and the second imaging unit 1b to measure the distance to the feature point F. In detail, the water area object detection system 103 (control unit 3) is configured to measure the distance to the feature point F corresponding to the object O in the captured image by triangulation, based on the images captured by the first imaging unit 1a and the second imaging unit 1b.

[0060] The "feature point F corresponding to the object O in the image" means a specific point shown in the part of the image where the object O is located. As an example, the feature point F is set in a part of the image where the change in brightness or the change in color tone is particularly large.

[0061] The water area object detection system 103 (control unit 3) is configured to perform pre-processing for distance measurement by triangulation, such as distortion correction of each image captured by the first imaging unit 1a and the second imaging unit 1b, parallelization to correspond each image to each other, estimation of parallax by matching corresponding feature points F on each image, and estimation of the relative position and relative orientation between the first imaging unit 1a and the second imaging unit 1b.

[0062] The measurement of the distance to the characteristic point F by triangulation performed by the water area object detection system 103 (control unit 3) will be described with reference to FIG.

[0063] If the horizontal distance (imaging direction) between the first imaging unit 1a and the second imaging unit 1b is L1, the vertical distance between the first imaging unit 1a and the second imaging unit 1b is x, the parallax between the first imaging unit 1a and the second imaging unit 1b is d, the element pitch of the imaging element of the first imaging unit 1a (second imaging unit 1b) is p, and the focal length of the first imaging unit 1a (second imaging unit 1b) is f, the horizontal distance L from the second imaging unit 1b to the feature point F (object O) can be calculated by the following formula (1). Note that the above parallax d is the difference in the coordinates on the image of the corresponding feature points of the images captured by each of the first imaging unit 1a and the second imaging unit 1b, and is expressed in pixels.

[0064]

number

[0065] The second imaging unit 1b is disposed with respect to the first imaging unit 1a so that the target error δ of the first imaging unit 1a and the second imaging unit 1b is 10 cm or less when the distance L to the object O imaged by the first imaging unit 1a and the second imaging unit 1b is 10 m or less. The target error δ is an estimated distance resolution determined by the resolution of the parallax d in the vicinity of the distance L = 10 m. Here, assuming that the resolution of the parallax d is in units of 1 pixel, and the adjacent parallaxes are da and db (for example, da = 10 pixels, db = 11 pixels), the resolution of the distance L, i.e., the target error δ (unit: [m]), can be calculated by the following formula (2).

[0066]

number

[0067] When considering the relationship between the linear distance D between the first imaging unit 1a and the second imaging unit 1b and the installation angle θ of the first imaging unit 1a with respect to the second imaging unit 1b based on the horizontal plane so as to satisfy the above error condition, the area above the dashed line shown in Fig. 9 satisfies the above error condition. In the area below the dashed line, the target error δ is greater than 10 cm.

[0068] Moreover, under the above error conditions, if the installation angle θ is set to 50 degrees or less and the distance D is set to 2.0 m or less, the hatched area in FIG. 9 satisfies the above error conditions.

[0069] (Configuration of the "display unit" of the water area object detection system) As shown in Figs. 3 and 4, the display unit 2 (see Fig. 1) is configured to display a water area map M created by the control unit 3 (see Fig. 1). As an example, the display unit 2 is configured to display the water area map M within a display image of 450 pixels wide by 600 pixels high. The display image of 450 pixels wide by 600 pixels high is a display image in which a point cloud is plotted in a world coordinate system. As an example, the size of one pixel of the water area map M corresponds to a size of 10 cm wide by 10 cm high in the world coordinate system.

[0070] The display unit 2 is also configured to display the hull 101 on the water area map M. The display unit 2 is configured to display the hull 101 on the water area map M using a schematic model.

[0071] The display unit 2 is configured to display the characteristic point F on the water area map M. The display unit 2 is also configured to display an object presence range F1 on the water area map M, which includes the possibility that an object O may exist around the characteristic point F. As a specific example, the control unit 3 is configured to perform control to display one characteristic point F in one pixel of the display unit 2, and to provide a perfect circular object presence range F1 around the one pixel displaying the characteristic point F, and to display it on the display unit 2. The closer the object presence range F1 is to the hull 101, the smaller the circular radius of the range F1 becomes.

[0072] Here, the object presence range F1 is a range provided around the characteristic point F, and is a range that includes the possibility that the object O exists. In short, the object presence range F1 indicates a range that is probabilistically considered to be likely to include the object O. In other words, the object presence range F1 is a range that should be avoided when the ship 100 moves, and the movement route of the ship 100 when moving is not set within the object presence range F1.

[0073] The display unit 2 is also configured to display on the water area map M an imaging area A with a predetermined angle of view that indicates the range currently being imaged by the first imaging unit 1a and the second imaging unit 1b.

[0074] (Configuration of the "control unit" of the water area object detection system) 1 is, for example, a circuit board including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The control unit 3 is connected to the first imaging unit 1a, the second imaging unit 1b, the display unit 2, and the marine vessel propulsion device 102 via signal lines.

[0075] The control unit 3 is configured to set a movement route r for automatic movement based on the created water area map M (see Figure 3) and to control the drive of the ship propulsion unit 102, thereby enabling control to automatically move the hull 101.

[0076] The control unit 3 detects a feature point F corresponding to an object O in the image along with the distance to the feature point F based on the images captured by the first imaging unit 1a and the second imaging unit 1b, and controls the creation of a water area map M having a perfect circular object existence range F1 around the feature point F, which includes the possibility that an object O may exist.

[0077] The control unit 3 is configured to create a two-dimensional water area map M extending horizontally around the hull 101 by setting an object existence range F1 in a horizontal plane perpendicular to the up-down direction (Z direction) in which the first imaging unit 1a and the second imaging unit 1b are arranged offset from each other.

[0078] (Correlation between the variance of the epipolar line angle and the error in the captured image) With reference to FIGS. 10 to 14, an embodiment and a comparative example regarding the correlation between the variance of the angle of the epipolar line and the error in the captured image will be described.

[0079] As shown in Fig. 10, the position of the first imaging unit was changed to arrangements 1 to 7 with respect to the second imaging unit whose arrangement was fixed, and images were captured. The imaging direction of the first imaging unit and the second imaging unit was BWD. Arrangements 2 and 3 of the first imaging unit are examples, and the others (arrangements 1 and 4 to 7) are comparative examples.

[0080] In first imaging unit arrangement 1, the first imaging unit is arranged directly in front of the second imaging unit. In first imaging unit arrangement 2, the first imaging unit is arranged on the rear lower side within the angle of view of the second imaging unit. In first imaging unit arrangement 3, the first imaging unit is arranged on the rear lower side outside the angle of view of the second imaging unit. In first imaging unit arrangement 4, the first imaging unit is arranged directly below the second imaging unit. In first imaging unit arrangement 5, the first imaging unit is arranged on the rear right side within the angle of view of the second imaging unit. In first imaging unit arrangement 6, the first imaging unit is arranged on the rear right side outside the angle of view of the second imaging unit. In first imaging unit arrangement 7, the first imaging unit is arranged directly to the right side within the angle of view of the second imaging unit.

[0081] Then, for each of the first imaging unit arrangements 1 to 7, a predetermined number of images (for example, 11 images) were captured, and the relative attitudes [deg] of pitch, yaw, and roll between the first imaging unit and the second imaging unit were estimated from the captured images. As an example, FIG. 11 shows the fluctuation in relative attitude between captured images of the first imaging unit arrangement 7. The image numbers in FIG. 11 indicate the number of images captured in order. In FIG. 11, it can be seen that the yaw varies greatly between each image, and the error in the relative attitude in the captured images (error in the relative attitude between the first imaging unit and the second imaging unit) is large. Note that in FIG. 11, it is ideal for all of the pitch, yaw, and roll to extend in a straight line in the horizontal direction, since this reduces the error in the relative attitude in the images.

[0082] Fig. 12 shows the standard deviation [deg] of the error in the relative attitude for pitch, yaw, and roll for each of arrangements 1 to 7 of the first imaging unit. It can be seen that the standard deviation [deg] of the error in all of the relative attitudes of pitch, yaw, and roll is small for arrangements 1 to 3 of the first imaging unit. On the other hand, it can be seen that the standard deviation [deg] of the error in any of the relative attitudes of pitch, yaw, and roll is large for arrangements 4 to 7 of the first imaging unit.

[0083] 13 shows the results of measuring the variance of the angles of epipolar lines when a certain number of feature points are specified and multiple epipolar lines are acquired in each of first imaging unit arrangements 1 to 7. In first imaging unit arrangements 4 and 7, the multiple epipolar lines are parallel lines extending vertically or horizontally on the image, so the variance is 0.

[0084] In the first imaging unit arrangements 5 and 6, the arrangement direction of the first imaging unit and the second imaging unit coincides with the extension direction of the imaging target (object whose feature points are to be acquired), so that multiple epipolar lines extend in the left-right direction on the image, and variance is reduced. The extension direction of the imaging target (object whose feature points are to be acquired) is the horizontal direction in which a pier or other shore structure extends. In the first imaging unit arrangements 1 to 3, the positions of the first imaging unit and the second imaging unit in the imaging direction are misaligned, and variance is increased.

[0085] Figure 14 shows the correlation between the error in the relative orientation between captured images and the variance of the epipolar line angle, along with the dashed power approximation curve. The R-squared value of the power approximation curve is 0.7049. When the variance is in the range of 0.3 or more, the measurement points are generally located on the power approximation curve. This shows that if the variance is at least 0.3 or more, the error in the relative orientation between the first and second imaging units can be kept sufficiently small.

[0086] (Effects of the embodiment) In this embodiment, the following effects can be obtained.

[0087] In this embodiment, as described above, the first imaging unit 1a and the second imaging unit 1b are provided to capture images of the object O around the hull 101, and the second imaging unit 1b is disposed at a position shifted in the vertical direction from the first imaging unit 1a, and the second imaging unit 1b is disposed at a position shifted in the vertical direction from the first imaging unit 1a so as not to overlap with the first imaging unit 1a in the imaging direction. Here, in the technology for creating a water area map using two imaging units with the same imaging direction, when the two imaging units are shifted in the imaging direction, the variance of the angles of the multiple epipolar lines becomes larger (the difference in angles becomes larger) compared to when the two imaging units are shifted only in a direction perpendicular to the imaging direction, such as the horizontal direction or the vertical direction. Therefore, with the above-mentioned configuration, the second imaging unit 1b can be disposed at a relatively large shifted position so as not to overlap with the first imaging unit 1a in the imaging direction so as to increase the variance of the angles of the multiple epipolar lines. As a result, the positional accuracy of the water area map M created based on the images captured by the first imaging unit 1a and the second imaging unit 1b can be improved. In addition, by disposing the second imaging unit 1b at a position shifted vertically from the first imaging unit 1a, the imaging range directly in front of the second imaging unit 1b can be prevented from being limited by the first imaging unit 1a. In addition, since the first imaging unit 1a and the second imaging unit 1b are separate, their positions can be freely adjusted.

[0088] In this embodiment, as described above, the first imaging unit 1a and the second imaging unit 1b are configured to capture images of the rear of the hull 101 in the imaging direction, and the second imaging unit 1b is disposed in a position shifted upward relative to the first imaging unit 1a and in a position shifted forward relative to the first imaging unit 1a. As a result, the first imaging unit 1a is disposed below the imaging direction of the second imaging unit 1b, and it is possible to prevent the first imaging unit 1a and the configuration for installing the first imaging unit 1a from being captured in the image captured by the second imaging unit 1b.

[0089] In this embodiment, as described above, the first imaging unit 1a and the second imaging unit 1b are provided, respectively, at the stern T of the hull 101 and the roof R of the hull 101. This makes it possible to easily arrange the first imaging unit 1a and the second imaging unit 1b by utilizing the existing configurations of the stern T and roof R so that the first imaging unit 1a is located below and rearward in the imaging direction of the second imaging unit 1b.

[0090] In this embodiment, as described above, the second imaging unit 1b is disposed at a position where the first imaging unit 1a fits within the imaging range of the second imaging unit 1b. This can prevent the second imaging unit 1b from being disposed in a manner where the first imaging unit 1a does not fit within the imaging range of the second imaging unit 1b. In other words, the second imaging unit 1b can be prevented from being disposed close to a manner where the first imaging unit 1a is arranged in a horizontal or vertical direction perpendicular to the imaging direction relative to the first imaging unit 1a. This can further improve the positional accuracy of the water area map M created based on the images captured by the first imaging unit 1a and the second imaging unit 1b.

[0091] In this embodiment, as described above, the installation angle of the first imaging unit 1a with respect to the second imaging unit 1b with respect to the horizontal plane as a reference is 50 degrees or less. This limits the installation angle of the first imaging unit 1a with respect to the second imaging unit 1b with respect to the horizontal plane as a reference to 50 degrees or less, so that it is possible to prevent the second imaging unit 1b from being disposed directly above the first imaging unit 1a due to the installation angle becoming too large. In other words, it is possible to prevent the arrangement of the second imaging unit 1b from being disposed in a direction perpendicular to the imaging direction of the first imaging unit 1a, such as the lateral direction or the vertical direction (directly above), so that it is possible to prevent the variance of the angles of the multiple epipolar lines from becoming small. This makes it possible to further improve the positional accuracy of the water area map M created based on the images captured by the first imaging unit 1a and the second imaging unit 1b.

[0092] In this embodiment, as described above, the control unit 3 is configured to automatically move the hull 101 toward the shore structure O1, which is the object O imaged by the first imaging unit 1a and the second imaging unit 1b, thereby automatically docking the hull 101. This makes it possible to easily dock the hull 101 at the shore structure O1.

[0093] In this embodiment, as described above, the second imaging unit 1b is disposed with respect to the first imaging unit 1a so that the target error of the first imaging unit 1a and the second imaging unit 1b is 10 cm or less when the distance to the object O imaged by the first imaging unit 1a and the second imaging unit 1b is 10 m or less. This makes it possible to keep the target error of the first imaging unit 1a and the second imaging unit 1b small, thereby further improving the positional accuracy of the water area map created based on the images imaged by the first imaging unit 1a and the second imaging unit 1b.

[0094] In this embodiment, as described above, the control unit 3 is configured to create a two-dimensional water area map M that spreads in the horizontal direction perpendicular to the up-down direction in which the first imaging unit 1a and the second imaging unit 1b are arranged offset from each other. This reduces the processing load of the control unit 3 compared to creating a three-dimensional water area map M that takes into account the up-down direction (height direction).

[0095] In this embodiment, as described above, the distance between the first imaging unit 1a and the second imaging unit 1b is 2.0 m or less. This allows the first imaging unit 1a and the second imaging unit 1b to be disposed relatively close to each other, so that the first imaging unit 1a and the second imaging unit 1b can be easily installed on a relatively small vessel 100.

[0096] In this embodiment, as described above, the control unit 3 is configured to detect a feature point F corresponding to an object O in an image based on images captured by the first imaging unit 1a and the second imaging unit 1b, and create a water area map M in which an object existence range F1 in which the object O may exist is provided around the feature point F. This allows the object existence range F1 that the ship 100 should avoid to be displayed on the water area map M, making it easy to grasp the object O that is in the vicinity of the hull 101.

[0097] In this embodiment, as described above, the overall length L10 of the hull 101 is 20 m or less. This makes it possible to provide a relatively small vessel 100 that can improve the positional accuracy of the water area map M created based on images captured by the first imaging unit 1a and the second imaging unit 1b.

[0098] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0099] For example, in the above embodiment, the installation angle of the first imaging unit relative to the second imaging unit with respect to the horizontal plane as the reference is set to 50 degrees or less, but the present invention is not limited to this. In the present invention, the installation angle of the first imaging unit relative to the second imaging unit with respect to the horizontal plane as the reference may be greater than 50 degrees.

[0100] In the above embodiment, the distance between the first and second imaging units is 2.0 m or less, but the present invention is not limited to this. In the present invention, the distance between the first and second imaging units may be greater than 2.0 m.

[0101] In the above embodiment, the overall length of the hull is 20 m or less, but the present invention is not limited to this. In the present invention, the overall length of the hull may be greater than 20 m.

[0102] In the above embodiment, the boat is an outboard motor boat, but the present invention is not limited to this. In the present invention, the boat may be a boat other than an outboard motor boat. For example, the boat may be a boat equipped with an inboard motor, an inboard / outboard motor, or a jet propulsion unit.

[0103] In the above embodiment, the object existence range is shown in a perfect circle shape on the water area map, but the present invention is not limited to this. In the present invention, the object existence range may be shown in a shape other than a perfect circle, such as an ellipse.

[0104] In the above embodiment, the imaging direction of the first imaging unit and the second imaging unit is the rear of the hull, but the present invention is not limited to this. In the present invention, the imaging direction of the first imaging unit and the second imaging unit may be a direction other than the rear of the hull, such as the front, left, or right of the hull.

[0105] In the above embodiment, the first imaging unit is provided at the stern of the hull, but the present invention is not limited to this. In the present invention, the first imaging unit may be provided at a position other than the stern of the hull.

[0106] In the above embodiment, the second imaging unit is provided on the roof of the hull, but the present invention is not limited to this. In the present invention, the second imaging unit may be provided at a position other than the roof of the hull.

[0107] In the above embodiment, the first imaging section, which is located further forward in the imaging direction than the second imaging section, is disposed below the second imaging section, but the present invention is not limited to this. In the present invention, the first imaging section, which is located further forward in the imaging direction than the second imaging section, may be disposed above the second imaging section. [Explanation of symbols]

[0108] 1a First imaging unit 1b Second imaging unit 3. Control Unit 100 ships 101 Hull 103 Water Object Detection System F feature points F1 Object presence range M Water Area Map O object O1 shore structure Rear roof T Stern

Claims

1. A first imaging unit provided on the hull and configured to capture an image of an object around the hull; a second imaging unit provided on the hull such that an imaging direction of the second imaging unit is substantially the same as that of the first imaging unit, and configured to capture an image of the object around the hull; a control unit that performs control to generate a water area map showing the range around the hull where the object is present by measuring distances to the objects imaged by the first imaging unit and the second imaging unit, the water area map being a two-dimensional map that displays a schematic model of the hull and a predetermined angle of view that indicates the range imaged by the first imaging unit and the second imaging unit, based on images captured by the first imaging unit and the second imaging unit, the second imaging unit is disposed at a position shifted in a vertical direction with respect to the first imaging unit, and is disposed at a position shifted in the imaging direction with respect to the first imaging unit so as not to overlap with the first imaging unit in the imaging direction; The control unit is configured to set a movement route for automatic movement that avoids the area on the water area map where the object exists, based on the water area map displayed on the display unit together with a schematic model of the hull, and to control the automatic movement of the hull along the movement route on the water area map.

2. The first imaging unit and the second imaging unit are configured to capture an image of a rear of the hull in the imaging direction, The water area object detection system according to claim 1 , wherein the second imaging unit is disposed at a position shifted upward relative to the first imaging unit and at a position shifted forward relative to the first imaging unit.

3. The water area object detection system according to claim 2 , wherein the first imaging unit and the second imaging unit are provided at a stern of the hull and a roof of the hull, respectively.

4. The water area object detection system according to claim 1 , wherein the second imaging unit is disposed at a position where the first imaging unit falls within an imaging range of the second imaging unit.

5. The water area object detection system according to claim 4 , wherein an installation angle of the first imaging unit relative to the second imaging unit with respect to a horizontal plane is equal to or smaller than 50 degrees.

6. The water area object detection system according to any one of claims 1 to 5, wherein the control unit is configured to automatically move the hull toward a shore structure, which is the object imaged by the first imaging unit and the second imaging unit, thereby automatically docking the hull.

7. The water area object detection system according to any one of claims 1 to 6, wherein the second imaging unit is positioned relative to the first imaging unit so that a target error of the first imaging unit and the second imaging unit is 10 cm or less when the distance to the object imaged by the first imaging unit and the second imaging unit is 10 m or less.

8. The water area object detection system according to any one of claims 1 to 7, wherein the control unit is configured to create a two-dimensional water area map that extends in a horizontal direction perpendicular to a vertical direction in which the first imaging unit and the second imaging unit are arranged offset from each other.

9. The water area object detection system according to any one of claims 1 to 8, wherein a distance between the first imaging unit and the second imaging unit is 2.0 m or less.

10. The water area object detection system of any one of claims 1 to 9, wherein the control unit is configured to detect feature points corresponding to the object in the image based on the images captured by the first imaging unit and the second imaging unit, and create the water area map with an object existence range around the feature points within which the object may exist.

11. A first imaging unit provided on the hull and configured to capture an image of the periphery of the hull; A second imaging unit configured separately from the first imaging unit and provided on the hull such that an imaging direction of the second imaging unit is substantially the same as that of the first imaging unit, and capturing an image of the periphery of the hull; a control unit that performs control to generate a water area map showing the range around the hull where an object captured by the first imaging unit and the second imaging unit exists by measuring a distance to the object captured by the first imaging unit and the second imaging unit, the water area map being a two-dimensional map that displays a schematic model of the hull and a predetermined angle of view that indicates the range captured by the first imaging unit and the second imaging unit, based on the images captured by the first imaging unit and the second imaging unit; the second imaging unit is disposed at a position shifted in the up-down direction relative to the first imaging unit and at a position shifted in the imaging direction relative to the first imaging unit, The control unit is configured to set a movement route for automatic movement that avoids the area on the water area map where the object exists, based on the water area map displayed on the display unit together with a schematic model of the hull, and to control the automatic movement of the hull along the movement route on the water area map.

12. The hull and a water area object detection system provided on the hull; The water body object detection system includes: A first imaging unit provided on the hull and configured to capture an image of an object around the hull; a second imaging unit provided on the hull such that an imaging direction of the second imaging unit is substantially the same as that of the first imaging unit, and configured to capture an image of the object around the hull; a control unit that performs control to measure distances to the objects imaged by the first imaging unit and the second imaging unit, and to create a water area map that indicates the area around the hull where the objects exist, the water area map being a two-dimensional map that displays a schematic model of the hull and a predetermined angle of view that indicates the range imaged by the first imaging unit and the second imaging unit, based on images captured by the first imaging unit and the second imaging unit, the second imaging unit is disposed at a position shifted in a vertical direction with respect to the first imaging unit, and is disposed at a position shifted in the imaging direction with respect to the first imaging unit so as not to overlap with the first imaging unit in the imaging direction; The control unit is configured to set a movement route for automatic movement avoiding the area on the water area map where the object exists, based on the water area map displayed on the display unit together with a schematic model of the hull, and to control the automatic movement of the hull along the movement route on the water area map.

13. 13. The vessel according to claim 12, wherein the overall length of the hull is 20 m or less.

14. The first imaging unit and the second imaging unit are configured to capture an image of a rear of the hull in the imaging direction, The vessel according to claim 12 or 13, wherein the second imaging unit is disposed at a position shifted upward relative to the first imaging unit and at a position shifted forward relative to the first imaging unit.

15. The watercraft according to claim 14 , wherein the first imaging unit and the second imaging unit are provided at a stern of the hull and a roof of the hull, respectively.

16. The vessel according to any one of claims 12 to 15, wherein the second imaging unit is disposed at a position where the first imaging unit falls within an imaging range of the second imaging unit.

17. The vessel according to claim 16 , wherein an installation angle of the first imaging unit with respect to the second imaging unit with respect to a horizontal plane is equal to or smaller than 50 degrees.

18. The ship described in any one of claims 12 to 17, wherein the control unit is configured to automatically dock the hull by automatically moving the hull toward a shore structure, which is the object to be imaged by the first imaging unit and the second imaging unit.

19. The ship described in any one of claims 12 to 18, wherein the second imaging unit is positioned relative to the first imaging unit so that a target error of the first imaging unit and the second imaging unit is 10 cm or less when a distance to the object imaged by the first imaging unit and the second imaging unit is 10 m or less.

20. A ship described in any one of claims 12 to 19, wherein the control unit is configured to create a two-dimensional water area map that extends in a horizontal direction perpendicular to the up-down direction in which the first imaging unit and the second imaging unit are arranged offset from each other.

Images