Underwater vehicle and position estimation system

Abstract

To provide an underwater navigation body capable of estimating its own position in water by using a light source installed in water.SOLUTION: An underwater vehicle (100) includes a first imaging unit (140) configured to image a first imaging range, a second imaging unit (160) configured to image a second imaging range different from the first imaging range, and a processor configured to determine a first distance in a first direction from the underwater vehicle to a first light source (210) based on a first captured image obtained by capturing light output from the first light source arranged in water by the first imaging unit, A distance determination unit configured to determine a second distance in a second direction from the underwater vehicle to a second light source based on a second captured image obtained by capturing light output from the second light source 220 different from the first light source by the second imaging unit; SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to underwater vehicles and position estimation systems. [Background technology]

[0002] Patent Document 1 describes a technique that can guide a diver to the location of a predetermined underwater search target. [Prior art document] [Patent documents] [Patent Document 1] JP 2024-044720 A Summary of the Invention [Means for solving the problem]

[0003] According to one embodiment of the present invention, there is provided an underwater vehicle. The underwater vehicle may include a first imaging unit that images a first imaging range. The underwater vehicle may include a second imaging unit that images a second imaging range different from the first imaging range. The underwater vehicle may include a distance determiner that determines a first distance in a first direction from the underwater vehicle to a first light source based on a first captured image of light output from the first light source located underwater, captured by the first imaging unit, and determines a second distance in a second direction from the underwater vehicle to the second light source based on a second captured image of light output from a second light source located underwater and different from the first light source, captured by the second imaging unit. The underwater vehicle may include a position estimator that estimates a position of the underwater vehicle based on the first distance and the second distance.

[0004] In the underwater vehicle, the distance determination unit may determine the first distance based on the first captured image captured by the first imaging unit of the light output from the first light source unit and the light output from the second light source unit of the first light source, and the light source unit spacing in a third direction perpendicular to the first direction between the first light source unit and the second light source unit.

[0005] In any of the underwater vehicles, the distance determiner may determine the first distance using the following formula: D1=(h1×f1) / (p D1 ×a D1 ), where D1 may be the first distance, h1 may be the light source unit interval, f1 may be the focal length of the lens of the first imaging unit, and p D1 may be the number of light receiving elements of the first imaging section that are present between a first light receiving element of the first imaging section that receives light output from the first light source unit and a second light receiving element of the first imaging section that receives light output from the second light source unit in a fourth direction corresponding to the third direction, and a D1 may be the length in the fourth direction of one light receiving element of the first imaging unit.

[0006] In any of the underwater vehicles, the distance determination unit may determine a third distance in a fifth direction from the underwater vehicle to the first light source, which is perpendicular to the first direction and the third direction, based on the first distance and the first captured image, and the position estimation unit may estimate the position of the underwater vehicle based further on the third distance.

[0007] In any of the underwater vehicles, the distance determiner may determine the third distance using the following formula: L1=(p L1 ×a L1 ×D1) / f1, where L1 may be the third distance, and p L1 may be the number of light receiving elements of the first imaging unit present between a first light receiving element of the first imaging unit that receives light output from the first light source unit in a sixth direction corresponding to the fifth direction and a center line of the imaging element of the first imaging unit including the first light receiving element that is perpendicular to a line parallel to the sixth direction, and a L1 may be the length in the sixth direction of one light receiving element of the first imaging unit, D1 may be the first distance, and f1 may be the focal length of a lens of the first imaging unit.

[0008] In any of the underwater vehicles, the first imaging unit may be mounted on a first surface of the body of the underwater vehicle, and the second imaging unit may be mounted on a second surface of the body of the underwater vehicle opposite the first surface.

[0009] Any of the underwater vehicles may further include an acquisition unit that acquires attitude information indicating the attitude of the underwater vehicle, and the distance determination unit may determine the first distance further based on the attitude information of the underwater vehicle.

[0010] Any of the underwater vehicles may further include a storage unit that stores size information indicating the size of the underwater vehicle, and the position estimation unit may estimate the position of the underwater vehicle based further on the size information.

[0011] Any of the underwater vehicles may further include a storage unit that stores identification information of the first light source in association with position information indicating the position where the first light source is located, and that stores identification information of the second light source in association with position information indicating the position where the second light source is located, and a communication unit that receives the identification information of the first light source from the first light source by optical camera communication (OCC) with the first light source using the first imaging unit, and receives the identification information of the second light source from the second light source by optical camera communication with the second light source using the second imaging unit, and the position estimation unit may estimate the underwater position of the underwater vehicle further based on the position information of the first light source stored in the storage unit in association with the identification information of the first light source and the position information of the second light source stored in the storage unit in association with the identification information of the second light source.

[0012] Any of the underwater vehicles may further include a communication unit that transmits position information indicating the underwater position of the underwater vehicle estimated by the position estimation unit to an information processing device located on the water surface by optical wireless communication with the information processing device while the underwater vehicle is located underwater.

[0013] According to one embodiment of the present invention, there is provided a position estimation system, which may include any of the underwater vehicles described above. The position estimation system may include a plurality of light sources, including the first light source and the second light source, disposed underwater.

[0014] In the position estimation system, the multiple light sources may be arranged underwater so that when the underwater vehicle is located in a space surrounded by the multiple light sources, the first imaging unit can capture light output from one of the multiple light sources, and the second imaging unit can capture light output from other light sources different from the one light source among the multiple light sources.

[0015] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions. [Brief explanation of the drawings]

[0016] [Figure 1] An example of a system 10 is shown schematically. [Figure 2] Another example of the system 10 is shown schematically. [Figure 3] Another example of the system 10 is shown schematically. [Figure 4] 2 is an explanatory diagram for explaining an example of the relationship between the position of the underwater vehicle 100 and the position of the light source. FIG. [Figure 5] 1 is an explanatory diagram for explaining an example of determining a distance used by the underwater vehicle 100 to estimate its own position in water. FIG. [Figure 6] 10 is an explanatory diagram for explaining another example of determining the distance used by the underwater vehicle 100 to estimate its own position in the water. FIG. [Figure 7] 1 is an explanatory diagram for explaining an example in which an underwater vehicle 100 estimates its own position in water. [Figure 8]10 is an explanatory diagram for explaining another example of determining the distance used by the underwater vehicle 100 to estimate its own position in the water. FIG. [Figure 9] FIG. 10 is an explanatory diagram for explaining another example of how the underwater vehicle 100 estimates its own position in water. [Figure 10] 1 is an explanatory diagram for explaining an example of the relationship between the tilt of the underwater vehicle 100 and the distance used by the underwater vehicle 100 to estimate its own position in the water. FIG. [Figure 11] 1 shows an example of the functional configuration of an underwater vehicle 100. [Figure 12] 2 shows an example of a functional configuration of an estimation device 400. [Figure 13] FIG. 2 is an explanatory diagram for explaining an example of a processing flow of the system 10. [Figure 14] 1 shows an example of the hardware configuration of a computer 1200 that functions as the underwater vehicle 100 or the estimation device 400. DETAILED DESCRIPTION OF THE INVENTION

[0017] When an underwater vehicle uses ultrasound to estimate its own position underwater, the ultrasound may be reflected multiple times and propagate over multiple paths, making it impossible to estimate its own position underwater with high accuracy. In the system according to this embodiment, for example, a mechanism is employed in which the estimation entity estimates its own position underwater using light. For example, the estimation entity estimates its own position in a space surrounded by multiple light sources placed underwater. Because light is less susceptible to multipath propagation than ultrasound, the estimation entity can estimate its own position underwater with high accuracy.

[0018] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0019] FIG. 1 schematically illustrates an example of a system 10. The system 10 may include an underwater vehicle 100. FIG. 1 illustrates an example in which the system 10 includes one underwater vehicle 100. The system 10 may include multiple underwater vehicles 100. The system 10 may include multiple light sources. The multiple light sources may be disposed underwater. FIG. 1 illustrates an example in which the system 10 includes two light sources, light source 210 and light source 220. The system 10 may include three or more light sources. The system 10 may include an information processing device 350.

[0020] The underwater vehicle 100 may be any underwater vehicle capable of performing any task underwater. The underwater vehicle 100 is, for example, an unmanned underwater vehicle. The unmanned underwater vehicle is, for example, an unmanned underwater vehicle (UUV). The unmanned underwater vehicle is, for example, a remotely operated vehicle (ROV). The unmanned underwater vehicle is, for example, an underwater drone. The unmanned underwater vehicle may be an autonomous underwater vehicle (AUV). The underwater vehicle 100 may be a manned underwater vehicle. FIG. 1 shows an example in which the underwater vehicle 100 is an underwater drone.

[0021] The underwater vehicle 100 performs, for example, a collection operation to collect objects underwater. The objects are, for example, herbivorous animals such as sea urchins and abalone. In this case, the underwater vehicle 100 performs the collection operation to prevent coastal erosion. The objects are, for example, garbage such as plastics, bottles, and cans. In this case, the underwater vehicle 100 performs the collection operation to clean up the water. The objects are, for example, marine products such as shellfish and seaweed. In this case, the underwater vehicle 100 performs the collection operation to harvest the marine products. The objects may be marine mineral resources such as manganese nodules and cobalt-rich crusts. In this case, the underwater vehicle 100 performs the collection operation to mine the marine mineral resources. The underwater vehicle 100 performs, for example, a survey operation to survey targets such as the bottom of a ship or the bottom of the sea. The underwater vehicle 100 may also perform any other operation.

[0022] The underwater vehicle 100 has a main body 102, an imaging unit 140, an imaging unit 160, a light source 170, a light receiving unit 180, and a mounting unit 190. Note that it is not essential that the underwater vehicle 100 has all of these components.

[0023] The underwater vehicle 100 may further include one or more sensors (not shown) that measure information related to the underwater vehicle 100. The sensors include an attitude sensor. The attitude sensor includes, for example, an acceleration sensor. The attitude sensor includes, for example, an angular velocity sensor. The attitude sensor includes, for example, an IMU (Inertial Measurement Unit). The sensors include, for example, a water depth sensor.

[0024] The imaging unit 140 captures an image of an imaging range 142. The imaging unit 140 captures, for example, light 215 output from a light source 210 installed underwater. The imaging unit 140 may be an example of a first imaging unit or an example of a second imaging unit.

[0025] The imaging unit 140 is, for example, a visible light camera. The imaging unit 140 is, for example, an infrared camera. The imaging unit 140 is, for example, a wide-angle camera. The imaging unit 140 may also be a stereo camera.

[0026] The imaging unit 160 captures an image of an imaging range 162. The imaging range 162 may be different from the imaging range 142. The imaging unit 160 captures, for example, light 225 output from a light source 220 placed underwater. The imaging unit 160 may be a camera similar to the imaging unit 140. The imaging unit 160 may be an example of a first imaging unit or an example of a second imaging unit.

[0027] The imaging unit 140 may be mounted on a first surface of the main body 102. The imaging unit 160 may be mounted on a second surface of the main body 102.

[0028] The second surface of the main body 102 is, for example, a surface different from the first surface of the main body 102. The second surface of the main body 102 is, for example, a surface opposite to the first surface of the main body 102. For example, if the first surface of the main body 102 is the front surface of the main body 102, the second surface of the main body 102 is the back surface of the main body 102. For example, if the first surface of the main body 102 is the right surface of the main body 102, the second surface of the main body 102 is the left surface of the main body 102.

[0029] The underwater vehicle 100 determines, for example, the distance in the first direction from the underwater vehicle 100 to the light source 210. The underwater vehicle 100 determines the distance in the first direction from the underwater vehicle 100 to the light source 210 based on, for example, a captured image of the light 215 captured by the imaging unit 140. Note that the captured image captured by the imaging unit 140 may be referred to as a first captured image, and the distance in the first direction determined by the underwater vehicle 100 based on the first captured image may be referred to as a first distance.

[0030] The underwater vehicle 100 determines, for example, the distance in the second direction from the underwater vehicle 100 to the light source 220. The underwater vehicle 100 determines the distance in the second direction from the underwater vehicle 100 to the light source 220 based on, for example, a captured image of the light 225 captured by the imaging unit 160. Note that the captured image captured by the imaging unit 160 may be referred to as a second captured image, and the distance in the second direction determined by the underwater vehicle 100 based on the second captured image may be referred to as a second distance.

[0031] For example, the second direction is parallel to the first direction. The second direction does not have to be parallel to the first direction. Figure 1 shows an example in which the first direction and the second direction are the x-axis direction shown in Figure 1.

[0032] Details of underwater vehicle 100 determining the distance from underwater vehicle 100 to the light source in a particular direction are described below. Figure 1 shows an example where the first distance is D1 and the second distance is D2.

[0033] The underwater vehicle 100, for example, estimates its own position in the water. The underwater vehicle 100 estimates its own position in the water based on, for example, a first distance and a second distance. The underwater vehicle 100 estimates its own position based further on, for example, the water depth of the underwater vehicle 100 measured by a depth sensor mounted on the underwater vehicle. Details of the underwater vehicle 100 estimating its own position in the water will be described later. The system 10 may be an example of a position estimation system.

[0034] The underwater vehicle 100 communicates with a light source disposed underwater using, for example, an optical camera. In optical camera communication, communication is performed using a camera, unlike conventional optical wireless communication in which communication is performed using a photodiode or a photomultiplier tube.

[0035] An example of data communication between a transmitter and a receiver in optical camera communication is as follows: The transmitter encodes the communication data into binary data of 1s and 0s and transmits the communication data to the receiver by using a light source to output light carrying an optical signal that is the binary data. The receiver receives the communication data from the transmitter by using a camera to receive the light output from the light source of the transmitter, analyzes the received light to obtain an optical signal, and decodes the obtained optical signal to obtain the communication data.

[0036] One advantage of optical camera communication is that it enables many-to-many communication because the receiver can simultaneously communicate with all transmitters whose light has been captured by the camera. Another advantage of optical camera communication is that it enables inexpensive configuration of transmitters and receivers because communication is performed between the transmitter and receiver by combining an inexpensive light source such as an LED (Light Emitting Diode) with a general camera, compared to conventional optical wireless communication that uses a photodiode and a photomultiplier tube to acquire optical signals on the receiver side.

[0037] The communication speed of optical camera communication may depend on the frame rate of the camera mounted on the receiver. For example, if the frame rate of the camera mounted on the receiver is 30 fps (flames per second), the communication speed of optical camera communication is 30 bps (bits per second). Therefore, optical camera communication is suitable for applications that do not require high-speed communication. For example, optical camera communication is suitable for applications such as acquiring sensor information from underwater IoT (Internet of Things) devices, updating firmware for underwater IoT devices, and guiding and controlling underwater robots.

[0038] The underwater vehicle 100 receives the identification information of the light source 210 from the light source 210, for example, by using the imaging unit 140 to communicate with the light source 210 via optical camera. The underwater vehicle 100 receives the identification information of the light source 220 from the light source 220, for example, by using the imaging unit 160 to communicate with the light source 210 via optical camera.

[0039] The light source 170 outputs light 175. The light source 170 outputs light 175 that can be received by a light receiving unit 380 that the vessel 300 has, for example.

[0040] The light source 170 outputs light 175 having a wavelength in the visible light range, for example. The light source 170 may also output light 175 having a wavelength in the infrared range.

[0041] The light source 170 is, for example, a laser. The light source 170 may be an LED.

[0042] The light receiving unit 180 receives light. The light receiving unit 180 can receive light 375 output from a light source 370 that the vessel 300 has, for example.

[0043] The light receiving section 180 receives, for example, light having a wavelength in the visible light region. The light receiving section 180 may also receive light having a wavelength in the infrared region.

[0044] The light receiving unit 180 is, for example, a camera. The light receiving unit 180 may also be a photodiode. The light receiving unit 180 may also include both a camera and a photodiode.

[0045] The mounting unit 190 may be disposed on the upper surface of the main body 102. The mounting unit 190 mounts, for example, the light source 170. The mounting unit 190 mounts, for example, the light receiving unit 180. The mounting unit 190 mounts, for example, the light source 170 and the light receiving unit 180.

[0046] The underwater vehicle 100 may have a plurality of mounting units 190. In this case, one of the plurality of mounting units 190 may be equipped with the light source 170, and another of the plurality of mounting units 190 different from the one mounting unit 190 may be equipped with the light receiving unit 180.

[0047] The mounting unit 190 has a function of controlling, for example, the orientation of at least one of the light source 170 and the light receiving unit 180. The mounting unit 190 controls the orientation of at least one of the light source 170 and the light receiving unit 180 based on, for example, attitude information of the underwater vehicle 100. The mounting unit 190 is, for example, a gimbal.

[0048] The light source 170 may be mounted directly on the body 102. The light receiving unit 180 may be mounted directly on the body 102.

[0049] The light source 210 outputs light 215. The light source 210 outputs light 215 that can be captured by, for example, the imaging section 140 and the imaging section 160. The light source 210 may be an example of a first light source or an example of a second light source.

[0050] The light source 210 outputs, for example, light 215 having a wavelength in the visible light region. The light source 210 outputs, for example, light 215 having a wavelength in the blue light region. The light source 210 may also output light 215 having a wavelength in the infrared region.

[0051] The light source 210 is, for example, a laser. The light source 210 may be an LED.

[0052] The light source 220 outputs light 225. The light source 220 outputs, for example, light source 255 that can be captured by the imaging section 140 and the imaging section 160. The light source 220 may be an example of a first light source or an example of a second light source.

[0053] The light source 220 may be a light source different from the light source 210. The light source 220 may output the same light as the light source 210 and may have the same function as the light source 210.

[0054] Light source 210 may be connected to vessel 300 via cable 219. Light source 220 may be connected to vessel 300 via cable 229.

[0055] The information processing device 350 has various functions. The information processing device 350 may be installed on the ship 300.

[0056] The information processing device 350 has, for example, an optical wireless communication function. The optical wireless communication is, for example, visible light communication. The optical wireless communication is, for example, infrared communication. The optical wireless communication is, for example, optical camera communication.

[0057] The information processing device 350, for example, communicates optically wirelessly with the underwater vehicle 100 located underwater. For example, the information processing device 350 outputs light 375 carrying an optical signal using a light source 370 included in the vessel 300. The underwater vehicle 100 receives the light using a light receiving unit 180 and analyzes the received light to obtain the optical signal. For example, the underwater vehicle 100 outputs light 175 carrying the optical signal using a light source 170. The information processing device 350 receives the light using a light receiving unit 380 included in the vessel 300 and analyzes the received light to obtain the optical signal.

[0058] The light source 370 outputs light 375. For example, the light source 370 outputs light 375 with a wavelength in the visible light region. The light source 370 may also output light 375 with a wavelength in the infrared region.

[0059] The light source 370 is, for example, a laser. The light source 370 may be an LED.

[0060] The light receiving unit 380 receives light. For example, the light receiving unit 380 receives light with a wavelength in the visible light region. The light receiving unit 380 may also receive light with a wavelength in the infrared region.

[0061] The light receiving unit 380 is, for example, a camera. The light receiving unit 380 may be a photodiode. The light receiving unit 380 may include both a camera and a photodiode.

[0062] The mounting unit 390 may be disposed on the bottom surface of the vessel 300. The mounting unit 390 mounts, for example, the light source 370. The mounting unit 390 mounts, for example, the light receiving unit 380. The mounting unit 390 mounts, for example, the light source 370 and the light receiving unit 380.

[0063] A plurality of mounting units 390 may be arranged on the bottom surface of the vessel 300. In this case, one of the plurality of mounting units 390 may be equipped with the light source 370, and another of the plurality of mounting units 390 different from the one mounting unit 390 may be equipped with the light receiving unit 380.

[0064] The mounting unit 390 has a function of controlling, for example, the orientation of at least one of the light source 370 and the light receiving unit 380. The mounting unit 390 is, for example, a gimbal.

[0065] The light source 370 may be mounted directly on the vessel 300. The light receiving unit 380 may be mounted directly on the vessel 300.

[0066] In recent years, there has been an increasing need to use underwater vehicles such as underwater drones to carry out collection and survey work. To carry out underwater work, underwater vehicles must estimate their own underwater position. However, in underwater environments where radio waves are significantly attenuated during propagation, it is difficult to estimate the vehicle's position using Global Navigation Satellite System (GNSS) technology.

[0067] Conventionally, underwater vehicles have estimated their own position in underwater environments using ultrasonic waves. However, ultrasonic waves tend to be reflected multiple times by the sea surface, the seabed, structures, etc., and propagate in multipaths. If multiple ultrasonic waves propagated in multipaths become mixed together, the underwater vehicle may not be able to estimate its own underwater position with high accuracy. Therefore, it is desirable for the underwater vehicle to be able to estimate its own underwater position with high accuracy.

[0068] In contrast, according to the system 10 of this embodiment, the underwater vehicle 100 determines the first distance and the second distance based on a first captured image capturing the light 215 output from the light source 210 and a second captured image capturing the light 225 output from the light source 220 using two imaging units 140 and 160 with different imaging ranges. The underwater vehicle 100 then estimates its underwater position based on the first distance and the second distance. Because the directivity of light is higher than that of ultrasound, light has the property of being less susceptible to multipath propagation compared to ultrasound. Therefore, the first distance and the second distance determined based on the captured images capturing the light having the above-described property are highly accurate information. Therefore, the underwater vehicle 100 estimates its underwater position based on the first distance and the second distance, which are multiple pieces of highly accurate information. The system 10 of this embodiment allows the underwater vehicle to estimate its underwater position with high accuracy. Furthermore, if the underwater vehicle 100 is equipped with a depth sensor, the underwater vehicle 100 can estimate its own position based on the water depth of the vehicle measured by the depth sensor, and the system 10 of this embodiment can estimate the three-dimensional position of the underwater vehicle with high accuracy.

[0069] 2 is a schematic diagram of another example of the system 10. Here, differences from the system 10 described above will be mainly described.

[0070] The system 10 may include an estimation device 400. The estimation device 400 has a function of estimating the position of the aircraft in water.

[0071] The estimation device 400 has a main body 402, a float 422, a weight 424, an imaging unit 440, an imaging unit 460, a light source 470, a light receiving unit 480, and a mounting unit 490. Note that it is not essential that the estimation device 400 has all of these components.

[0072] The estimation device 400 may further include one or more sensors (not shown) that measure information related to the estimation device 400. The sensors mounted on the estimation device 400 may be the same sensors as those mounted on the underwater vehicle 100.

[0073] The imaging unit 440 captures an image of an imaging range 442. The imaging unit 440 captures, for example, light 215 output from a light source 210 installed underwater. The imaging unit 440 may be an imaging unit having the same function as the imaging unit mounted on the underwater vehicle 100.

[0074] The imaging unit 460 captures an image of an imaging range 462. The imaging range 462 may be different from the imaging range 442. The imaging unit 460 captures, for example, light 225 output from a light source 220 placed underwater. The imaging unit 460 may be an imaging unit having the same function as the imaging unit mounted on the underwater vehicle 100.

[0075] The imaging unit 440 may be mounted on a first surface of the main body 402. The imaging unit 460 may be mounted on a second surface of the main body 402. The imaging units 440 and 460 may be mounted on the main body 402 in the same manner as when the imaging units 140 and 160 are mounted on the main body 102.

[0076] The estimation device 400 determines the distance in a first direction from the estimation device 400 to the light source 210, for example, based on a captured image of the light 215 captured by the imaging unit 440. The estimation device 400 determines the distance in a second direction from the estimation device 400 to the light source 220, for example, based on a captured image of the light 225 captured by the imaging unit 460. FIG. 2 shows an example in which the first direction and the second direction are the x-axis direction shown in FIG. 2, the first distance is D1, and the second distance is D2.

[0077] The estimation device 400 estimates, for example, the underwater position of the vehicle itself. The estimation device 400 may estimate the underwater position of the vehicle itself in the same manner as when the underwater vehicle 100 estimates the underwater position of the vehicle itself.

[0078] The estimation device 400, for example, communicates with a light source disposed underwater via optical camera. The estimation device 400, for example, receives identification information of the light source 210 from the light source 210 by optical camera communication with the light source 210 using the imaging unit 440. The estimation device 400, for example, receives identification information of the light source 220 from the light source 220 by optical camera communication with the light source 210 using the imaging unit 460.

[0079] The float 422 may be mounted on the main body 402. The weight 424 may be mounted on the float 422. For example, the combination of the float 422 and the weight 424 is selected so that the estimator 400 has attitude stability in the vertically upward direction.

[0080] The estimation device 400 has, for example, neutral buoyancy. Neutral buoyancy is the buoyancy that causes an object to neither float nor sink in water. The estimation device 400 may have a buoyancy greater than neutral buoyancy.

[0081] The estimation device 400 is connected to a tank 580 of a user 500 via a tether 550. The user 500 may be a diver.

[0082] The light source 470 outputs light 475. The light source 470 outputs light 475 that can be received by the light receiving unit 380, for example. The light source 470 may output the same light as the light source 170 and may have the same function as the light source 170.

[0083] The light receiving unit 480 receives light. For example, the light receiving unit 480 can receive light 375 output from the light source 370. The light receiving unit 480 may receive the same light as the light received by the light receiving unit 180, and may have the same function as the light receiving unit 180.

[0084] Mounting unit 490 may be disposed on the upper surface of main body 402. Mounting unit 490 may mount an object in the same manner as mounting unit 190 mounts an object, and may have the same function as mounting unit 190. Mounting unit 490 is, for example, a gimbal.

[0085] The light source 470 may be mounted directly on the body 402. The light receiving unit 480 may be mounted directly on the body 402.

[0086] 3 is a schematic diagram of another example of the system 10. Here, differences from the system 10 described above will be mainly described.

[0087] The light source 210 includes, for example, a light source unit 212 and a light source unit 216. The light source unit 212 outputs light 213. The light source unit 212 outputs light 213 that can be captured by, for example, the imaging sections 140 and 160. The light source unit 216 outputs light 217. The light source unit 216 outputs light 217 that can be captured by, for example, the imaging sections 140 and 160.

[0088] The light source unit 212 may output light similar to that of the light source 210. The light source unit 216 may output light similar to that of the light source 210.

[0089] For example, the light source unit 216 outputs light 217 in the same wavelength region as the wavelength region of the light 213 output by the light source unit 212. The light source unit 216 may output light 217 in a wavelength region different from the wavelength region of the light 213 output by the light source unit 212.

[0090] The light source unit 212 is, for example, a laser or an LED. The light source unit 216 is, for example, a laser or an LED.

[0091] The light source unit 212 may be an example of a first light source unit, and the light source unit 216 may be an example of a second light source unit.

[0092] The underwater vehicle 100 determines the first distance based on, for example, a first captured image captured by the imaging section 140 of the light 213 output from the light source unit 212 and the light 217 output from the light source unit 216, and the light source unit interval in a third direction perpendicular to the first direction between the light source unit 212 and the light source unit 216. Figure 3 shows an example in which the first direction is the x-axis direction shown in Figure 3, the third direction is the y-axis direction shown in Figure 3, and the light source unit interval in the third direction between the light source unit 212 and the light source unit 216 is h1.

[0093] The light source 220 includes, for example, a light source unit 222 and a light source unit 226. The light source unit 222 outputs light 223. The light source unit 226 outputs light 227.

[0094] The light source unit 222 may output the same light as the light source unit 212 and may have the same function as the light source unit 212. The light source unit 226 may output the same light as the light source unit 216 and may have the same function as the light source unit 216.

[0095] The light source unit 222 may be an example of a first light source unit, and the light source unit 226 may be an example of a second light source unit.

[0096] The underwater vehicle 100 determines the second distance based on, for example, a second captured image captured by the imaging section 160 of the light 223 output from the light source unit 222 and the light 227 output from the light source unit 226, and the light source unit spacing in a third direction perpendicular to the second direction between the light source unit 222 and the light source unit 226. Figure 3 shows an example in which the second direction is the x-axis direction shown in Figure 3, the third direction is the y-axis direction shown in Figure 3, and the light source unit spacing in the third direction between the light source unit 222 and the light source unit 226 is h2.

[0097] 4 is an explanatory diagram illustrating an example of the relationship between the position of the underwater vehicle 100 and the position of the light source. Here, it is assumed that the underwater vehicle 100 is located below the light source 210 and the light source 220.

[0098] If the underwater vehicle 100 is capable of capturing images of the light output from the light source 210 and the light output from the light source 220, it can determine D1 and D2 even when the underwater vehicle 100 is located below the light source 210 or the light source 220, as shown in Fig. 4, or when the underwater vehicle 100 is located above the light source 210 or the light source 220. Therefore, a wide-angle camera with a wide imaging range is more suitable as the imaging unit to be mounted on the underwater vehicle 100.

[0099] 5 is an explanatory diagram for explaining an example in which the underwater vehicle 100 determines the distance used to estimate its own position in the water. Here, an example in which the underwater vehicle 100 determines D1 will be mainly described.

[0100] The imaging unit 140 includes a lens 145. The imaging unit 140 includes an imaging element 148.

[0101] The lens 145 may have a function of focusing light. In the example shown in Figure 5, the focal length of the lens 145 is f1.

[0102] The image sensor 148 may have a function of converting light into an electrical signal, and may include a plurality of light receiving elements.

[0103] The upper diagram of Fig. 5 is an explanatory diagram for explaining an example of condensing light by lens 145. In the example shown in the upper diagram of Fig. 5, lens 145 condenses light 213 output from light source unit 212 onto light receiving element 1481 of image sensor 148, and condenses light 217 output from light source unit 216 onto light receiving element 1482 of image sensor 148. Light receiving element 1481 may be an example of a first light receiving element, and light receiving element 1482 may be an example of a second light receiving element.

[0104] In the upper diagram of Figure 5, △ABC is a right triangle with a right angle at angle C. As shown in the upper diagram of Figure 5, the length of side AC is D1 and the length of side BC is h1.

[0105] In the upper diagram of Figure 5, △EFG is a right triangle with angle G as a right angle. As shown in the upper diagram of Figure 5, the length of side EG is f1, and the length of side FG is p D1 ×a D1 where p D1 is the number of light receiving elements of the imaging section 140 present between the light receiving element 1481 that receives the light 213 output from the light source unit 212 and the light receiving element 1482 that receives the light 217 output from the light source unit 216 in the fourth direction corresponding to the third direction that is the spacing direction of h1, and a D1 is the length in the fourth direction of one light receiving element of the imaging section 140. In Fig. 5, an example is shown in which the third direction and the fourth direction are the y-axis direction shown in Fig. 5.

[0106] In the upper diagram of Figure 5, triangle ABC and triangle EFG are in a similar relationship, so D1:f1=h1:p D1 ×a D1 Therefore, the underwater vehicle 100 has the following relationship: D1=(h1×f1) / (p D1 ×a D1 ) to determine D1.

[0107] The lower diagram of Fig. 5 shows an example of the image sensor 148. As shown in the lower diagram of Fig. 5, the number of light receiving elements present between the light receiving element 1481 and the light receiving element 1482 in the y-axis direction is six. Therefore, in the example shown in the lower diagram of Fig. 5, p D1 ×a D1 =6×a D1 is.

[0108] 6 is an explanatory diagram for explaining another example of how the underwater vehicle 100 determines the distance used to estimate its own position in the water. Here, the case where the underwater vehicle 100 in a tilted state determines the distance used to estimate its own position in the water will be mainly explained.

[0109] The upper diagram in Fig. 6 is an explanatory diagram illustrating an example in which the underwater vehicle 100 in a tilted state determines the distance used to estimate its own position in the water. The underwater vehicle 100 determines its own tilt by, for example, acquiring attitude information indicating the attitude of the underwater vehicle 100. The underwater vehicle 100 acquires its own attitude information by, for example, using an attitude sensor mounted on the underwater vehicle.

[0110] The inclination of the underwater vehicle 100 is expressed, for example, by the roll angle of the underwater vehicle 100. The inclination of the underwater vehicle 100 is expressed, for example, by the pitch angle of the underwater vehicle 100. The inclination of the underwater vehicle 100 is expressed, for example, by the yaw angle of the underwater vehicle 100. The inclination of the underwater vehicle 100 is expressed, for example, by a combination of at least two of the roll angle, pitch angle, and yaw angle of the underwater vehicle 100. In FIG. 6, the underwater vehicle 100 is tilted at a pitch angle θ P An example is shown in which the angle is tilted only by 1.

[0111] The underwater vehicle 100 is P When the underwater vehicle 100 is tilted by θ θ 1 , the distance based on the captured image of the light 215 captured by the underwater vehicle 100 using the imaging unit 140 is determined to be θ θ 1 , with respect to the first direction from the underwater vehicle 100 to the light source 210. P In FIG. 6, the first direction is the x-axis direction, and the distance from the underwater vehicle 100 to the light source 210 is inclined by θ P The distance in the direction tilted by only D 1c An example is shown.

[0112] The underwater vehicle 100 determines θ in the same manner as in the case of determining D1 described above. P Based on the captured image of the light 215 captured by the image capturing unit 140 in a state where the light 215 is tilted by D 1c Specifically, the underwater vehicle 100 may determine D 1c =(h1×f1) / (p D1 ×a D1 ) to D 1c Determine.

[0113] In order for the underwater vehicle 100 to estimate its own underwater position with high accuracy, it is desirable for the underwater vehicle 100 to capture the light output from the light source placed underwater while the vehicle is not tilted. However, when the underwater vehicle 100 is performing work such as collection work or survey work, the underwater vehicle 100 may need to capture the light output from the light source placed underwater while the vehicle is tilted. Therefore, the underwater vehicle 100 uses D 1c D1 is determined based on the tilt of the aircraft.

[0114] The lower diagram of Fig. 6 is an explanatory diagram illustrating an example of the relationship between the tilt of the underwater vehicle 100 and the distance that the underwater vehicle 100 uses to estimate its own position in the water. As shown in the lower diagram of Fig. 6, D 1c is the hypotenuse of a right triangle, D1 is one of the two adjacent sides of the right triangle, and θ P is D 1c and D1. 1c and D1 and θ P From the relationship, the underwater vehicle 100 has D1=D 1c ×cosθ P =(h1×f1) / (p D1 ×a D1 )×cosθ P D1 is determined from the above equation. As a result, the underwater vehicle 100 can determine D1 even when it is tilted, and therefore the underwater vehicle 100 shown in Fig. 6 can estimate its own position in the water with high accuracy even when it is tilted.

[0115] 7 is an explanatory diagram illustrating an example of an underwater position estimation performed by the underwater vehicle 100. The system 10 may include a light source 251, a light source 252, a light source 253, a light source 254, a light source 255, a light source 256, a light source 257, a light source 261, a light source 262, a light source 263, a light source 264, a light source 265, a light source 266, and a light source 267.

[0116] The light sources 251 to 267 described above may output the same light as the light source 210 and may have the same function as the light source 210. The light sources 251 to 267 described above may output light in different wavelength regions. The light sources 251 to 267 described above may be referred to as a plurality of light sources.

[0117] The space 50 is a space surrounded by a plurality of light sources. The plurality of light sources are arranged in water, for example, so that the space 50 is a rectangular space. The plurality of light sources are arranged in water, for example, so that the space 50 is a circular space. The plurality of light sources may be arranged in water so that the space 50 is a space of any other shape. FIG. 7 shows an example of a case where a plurality of light sources are arranged in water to form a rectangular space 50 having a length in the x-axis direction of W and a length in the y-axis direction of H.

[0118] The multiple light sources are arranged underwater, for example, so that the imaging unit 140 or the imaging unit 160 can capture an image of light output from one of the multiple light sources when the underwater vehicle 100 is located in the space 50. The multiple light sources are arranged underwater, for example, so that the imaging unit 140 can capture an image of light output from one of the multiple light sources when the underwater vehicle 100 is located in the space 50, and so that the imaging unit 160 can capture an image of light output from another light source different from the one of the multiple light sources. Figure 7 shows an example of a case where the underwater vehicle 100 is located in a position in the space 50 where the imaging unit 140 can capture an image of light output from the light source 253 and the imaging unit 140 can capture an image of light output from the light source 263.

[0119] Here, we will explain an example in which the underwater vehicle 100 located in the space 50 estimates its own position in the water. Here, we assume that the underwater vehicle 100 stores identification information for each of a plurality of light sources in association with position information indicating the location where each light source is located.

[0120] The underwater vehicle 100 determines D1, for example, based on a first captured image obtained by the imaging unit 140 capturing light output from the light source 253. The underwater vehicle 100 determines the distance in a fifth direction perpendicular to the first and third directions from the underwater vehicle 100 to the light source 253, for example, based on D1 and the first captured image. Figure 7 shows an example in which the first direction is the y-axis direction, the third direction is the z-axis direction, and the fifth direction is the x-axis direction.

[0121] The distance in the fifth direction determined by the underwater vehicle 100 based on the first captured image may be referred to as the third distance. Figure 7 shows an example in which the third distance is L1.

[0122] The underwater vehicle 100 receives the identification information of the light source 253 from the light source 253, for example, by optical camera communication with the light source 253 using the imaging unit 140. The underwater vehicle 100 receives the identification information of the light source 253 from the light source 253, for example, by detecting the position (X 253 , 0), D1, and L1, the position of the aircraft in the water (x UV ,y UV ) is estimated. In this case, x UV =X 253 +L1, and y UV =D1.

[0123] The underwater vehicle 100 determines D2, for example, based on a second captured image obtained by the imaging unit 160 capturing light output from the light source 263. The underwater vehicle 100 determines the distance in a seventh direction perpendicular to the second and third directions from the underwater vehicle 100 to the light source 263, for example, based on D2 and the second captured image. Figure 7 shows an example in which the second direction is the y-axis direction and the seventh direction is the x-axis direction.

[0124] The distance in the seventh direction determined by the underwater vehicle 100 based on the second captured image may be referred to as the fourth distance. In Fig. 7, an example is shown in which the fourth distance is L2.

[0125] The underwater vehicle 100 receives the identification information of the light source 263 from the light source 263, for example, by optical camera communication with the light source 263 using the imaging unit 160. The underwater vehicle 100 receives the identification information of the light source 263 from the light source 263, for example, by detecting the position (X 263 , H), D2, and L2, the position of the aircraft in the water (x UV ,y UV ) is estimated. In this case, x UV =X 263 +L2 and y UV =H-D2.

[0126] The underwater vehicle 100 may be, for example, 253 ,0), D1, L1, and (X 263 , H), D2, and L2, (x UV ,y UV ) is estimated. In this case, x UV ={(X 253 +L1)+(X 263 +L2)} / 2, and y UV ={D1+(H-D2)} / 2.

[0127] The underwater vehicle 100 determines its own position (x UV ,y UV ) is estimated. The size information includes, for example, first length information indicating the length from the imaging unit 140 to the center of gravity of the underwater vehicle 100. The size information includes, for example, second length information indicating the length from the imaging unit 160 to the center of gravity of the underwater vehicle 100. In FIG. 7, the length from the imaging unit 140 to the center of gravity of the underwater vehicle 100 is l UV1 and the length from the imaging unit 160 to the center of gravity of the underwater vehicle 100 is l UV2 An example is shown.

[0128] For example, in the example shown in FIG. 253 , 0), D1, L1, and the size information of the underwater vehicle 100, the position (x UV ,y UV) is estimated, x UV =X 253 +L1, and y UV =D1+l UV1 For example, in the example shown in FIG. 263 , H), D2, L2, and the size information of the underwater vehicle 100, the position (x UV ,y UV ) is estimated, x UV =X 263 +L1, and y UV =H-D2-l UV2 For example, in the example shown in FIG. 253 ,0), D1, L1, and (X 263 , H), D2, L2, and the size information of the underwater vehicle 100, the position (x UV ,y UV ) is estimated, x UV ={(X 253 +L1)+(X 263 +L2)} / 2, and y UV ={(D1+l UV1 )+(H-D2-l UV2 )} / 2.

[0129] The underwater vehicle 100 may, for example, measure the water depth z measured by a water depth sensor mounted on the vehicle. UV In this case, the underwater vehicle 100 may estimate the underwater position of the vehicle based on the three-dimensional position (x UV ,y UV ,z UV ) is estimated.

[0130] According to the system 10 shown in FIG. 7 , when the underwater vehicle 100 is located in a space 50 surrounded by multiple light sources, the imaging unit 140 or the imaging unit 160 is arranged underwater so that the imaging unit 140 or the imaging unit 160 can capture light output from one of the multiple light sources. Therefore, the underwater vehicle 100 can estimate its own position in the space 50 while it is located in the space 50. Furthermore, the shape and size of the space 50 can be flexibly changed by changing the number and positions of the multiple light sources arranged underwater. As a result, the system 10 shown in FIG. 7 can flexibly design a space in which the underwater vehicle 100 can estimate its own position in the water by arranging multiple light sources underwater. Furthermore, when the underwater vehicle 100 is located in the space 50, multiple light sources may be arranged underwater so that the imaging unit 140 can capture light output from one of the multiple light sources and the imaging unit 160 can capture light output from a light source other than the one of the multiple light sources. By arranging multiple light sources underwater in this manner, the system 10 according to Fig. 7 can flexibly design a space in which the underwater vehicle 100 can estimate its own underwater position with high accuracy. In addition, if the underwater vehicle 100's ability to capture light output from one of the multiple light sources is set as an implementation condition for the underwater vehicle 100 to perform work, the system 10 according to Fig. 7 can flexibly design a geofence for the underwater vehicle 100 by arranging multiple light sources underwater. Note that a geofence is an area surrounded by a virtual boundary line.

[0131] 8 is an explanatory diagram for explaining another example in which the underwater vehicle 100 determines the distance used to estimate its own position in the water. Here, an example in which the underwater vehicle 100 determines L1 will be mainly explained. It is assumed that the underwater vehicle 100 has already determined D1.

[0132] 8 is an explanatory diagram for explaining an example of light collection by the lens 145 of the imaging section 140. In the example shown in the upper diagram of FIG. 8, the lens 145 collects light 213 output from the light source unit 212 onto the light receiving element 1483 of the imaging element 148.

[0133] In the upper diagram of Figure 8, △A'B'C' is a right triangle with angle C' as a right angle. As shown in the upper diagram of Figure 8, the length of side A'C' is D1 and the length of side B'C' is L1.

[0134] In the upper diagram of Figure 8, △E'F'G' is a right triangle with angle G' as a right angle. As shown in the upper diagram of Figure 8, the length of side E'G' is f1, and the length of side F'G' is p L1 ×a L1 where p L1 is a distance between the light receiving element 1483 of the imaging section 140 that receives the light 213 output from the light source unit 212 in a sixth direction corresponding to the fifth direction, which is the length direction of L1, and the center line l of the imaging element 148 that is perpendicular to a line parallel to the sixth direction. c The number of light receiving elements of the image capturing unit 140 that exist between the first light receiving element 1483 and the second light receiving element 1484 is an example of the first light receiving element. c is perpendicular to the image sensor 148 and is the center C of the lens 145 p Line l passing through n Intersects with a L1 is the length in the sixth direction of one light receiving element of the imaging unit 140. In FIG. 8, the fifth and sixth directions are the z-axis direction shown in FIG. c is a line parallel to the y-axis, and l n An example is shown in which is a line parallel to the x-axis.

[0135] In the upper diagram of Figure 8, △A'B'C' and triangle E'F'G' are in a similar relationship, so D1:f1=L1:p L1 ×a L1 Therefore, the underwater vehicle 100 has the following relationship: L1=(p L1 ×a L1 Determine L1 from (×D1) / f1.

[0136] The lower diagram of Fig. 8 shows another example of the image sensor 148. As shown in the lower diagram of Fig. 8, the light receiving element 1483 and the light receiving element 1484 are arranged in the z-axis direction. c The number of light receiving elements between p L1 ×aL1 =4×a L1 is.

[0137] 9 is an explanatory diagram for explaining another example of how the underwater vehicle 100 estimates its own position in the water. Y The following mainly describes a case where an underwater vehicle 100 located in a space 50 with only a slight tilt estimates its own position in the water.

[0138] For example, the underwater vehicle 100 determines an angle θ with respect to a first direction from the underwater vehicle 100 to the light source 253 based on a first captured image obtained by the imaging unit 140 capturing light output from the light source 253. Y Distance D in the direction tilted by 1c The underwater vehicle 100 determines D 1c Based on this, θ is set to a fifth direction from the underwater vehicle 100 to the light source 253. Y Distance L in the direction tilted by 1c The underwater vehicle 100 determines D 1c and L 1c Based on this, the distance D' from the underwater vehicle 100 to the light source 253 1c And, D 1c and D' 1c The underwater vehicle 100 determines the angle θ1 between the 1c and θ Y and θ1, D1 and L1 are determined. Thereafter, the underwater vehicle 100 determines the position (X 253 , 0), D1, and L1, the position of the aircraft in the water (x UV ,y UV ) is estimated. FIG. 9 shows an example in which the first direction is the y-axis direction and the fifth direction is the x-axis direction.

[0139] For example, the underwater vehicle 100 may determine an angle θ with respect to a first direction from the underwater vehicle 100 to the light source 264 based on a second captured image obtained by the imaging unit 160 capturing the light output from the light source 264. YDistance D in the direction tilted by 2c The underwater vehicle 100 determines D 2c Based on this, θ is set to a fifth direction from the underwater vehicle 100 to the light source 264. Y Distance L in the direction tilted by 2c The underwater vehicle 100 determines D 2c and L 2c Based on this, the distance D' from the underwater vehicle 100 to the light source 264 2c And, D 2c and D' 2c The underwater vehicle 100 determines the angle θ2 between D' and 2c and θ Y and θ2, D2 and L2 are determined. Thereafter, the underwater vehicle 100 determines the position (X 264 , H), D2, and L2, the position of the aircraft in the water (x UV ,y UV ) is estimated.

[0140] The underwater vehicle 100 determines its own position (x UV ,y UV ) is estimated. For example, in the example shown in FIG. 253 , 0), D1, L1, and the size information of the underwater vehicle 100, the position (x UV ,y UV ) is estimated, x UV =X 253 +L1+l UV1 ×sinθ Y and y UV =D1+l UV1 ×cosθ Y For example, in the example shown in FIG. 264 , H), D2, L2, and the size information of the underwater vehicle 100, the position (x UV ,y UV ) is estimated, x UV =X264 +L1-l UV2 ×sinθ Y and y UV =H-D2-l UV2 ×cosθ Y For example, in the example shown in FIG. 253 ,0), D1, L1, and (X 264 , H), D2, L2, and the size information of the underwater vehicle 100, the position (x UV ,y UV ) is estimated, x UV ={(X 253 +L1+l UV1 ×sinθ Y )+(X 264 +L1-l UV2 ×sinθ Y )} / 2, and y UV ={(D1+l UV1 ×cosθ Y )+(H-D2-l UV2 ×cosθ Y )} / 2.

[0141] 10 is an explanatory diagram for explaining an example of the relationship between the tilt of the underwater vehicle 100 and the distance used by the underwater vehicle 100 to estimate its own position in the water. Here, details of the case where the underwater vehicle 100 shown in FIG. 9 estimates its own position in the water will be mainly explained.

[0142] The upper diagram of Figure 10 shows the Y For example, the underwater vehicle 100 determines D in the same manner as in the case of determining D1 described above. 1c =(h1×f1) / (p D1 ×a D1 ) to D 1c The underwater vehicle 100 determines L in the same manner as in the case of determining L1 described above. 1c =(p L1 ×a L1 ×D1) / f1, L 1c The underwater vehicle 100 determines D' 1c ={(D 1c ) 2 +(L 1c )2} 1 / 2 From D' 1c Determine θ1=arctan(L 1c / D 1c ) to determine θ1.

[0143] The bottom diagram of Figure 10 shows the Y 1 shows an example of the relationship between D2 and L2. 1c , L 1c , D' 1c , θ1, D 2c , L 2c , D' 2c , θ2 is determined.

[0144] where D' nc and D n and θ n and θ Y The relationship between these two will be explained below. Note that n is 1 or 2.

[0145] For example, if the light output from the light source included in the captured image is located to the right of the center line in the horizontal direction of the captured image and the underwater vehicle 100 is tilted in the positive rotation direction, or if the light output from the light source included in the captured image is located to the left of the center line in the horizontal direction of the captured image and the underwater vehicle 100 is tilted in the negative rotation direction, D n =D' nc ×cos(θ Y +θ n On the other hand, if the light output from the light source included in the captured image is located to the left of the center line in the horizontal direction of the captured image and the underwater vehicle 100 is tilted in the positive rotation direction, or if the light output from the light source included in the captured image is located to the right of the center line in the horizontal direction of the captured image and the underwater vehicle 100 is tilted in the negative rotation direction, D n =D' nc ×cos(θ Y -θ n ) where a positive rotation direction is a clockwise rotation direction and a negative rotation direction is a counterclockwise rotation direction.

[0146] The light output from the light source 253 included in the first captured image captured by the imaging unit 140 at the position of the underwater vehicle 100 shown in Figure 9 is located to the left of the center line in the left-right direction of the first captured image. Also, the light output from the light source 264 included in the second captured image captured by the imaging unit 160 at the position of the underwater vehicle 100 shown in Figure 9 is located to the right of the center line in the left-right direction of the second captured image. And, the underwater vehicle 100 in the state shown in Figure 9 is tilted in the negative rotation direction. Therefore, in the example shown in Figure 9, the underwater vehicle 100 is tilted in the negative rotation direction such that D1 = D' 1c ×cos(θ Y +θ1), and D2 = D' 2c ×cos(θ Y -θ2).

[0147] The underwater vehicle 100 is configured as follows: L1={(D' 1c ) 2 -(D 1c ) 2} 1 / 2 The underwater vehicle 100 determines L1 from L2 = {(D' 2c ) 2 -(D 2c ) 2} 1 / 2 From this, determine L2.

[0148] 11 shows an example of the functional configuration of the underwater vehicle 100. The underwater vehicle 100 includes a storage unit 103, an acquisition unit 104, a distance determination unit 106, a position estimation unit 108, a communication unit 110, an imaging unit 140, an imaging unit 160, a light source 170, and a light receiving unit 180. Note that it is not essential that the underwater vehicle 100 include all of these components.

[0149] The storage unit 103 stores various types of information. For example, the storage unit 103 stores identification information of each of the multiple light sources in association with position information of each light source. For example, the storage unit 103 stores wavelength region information indicating the wavelength region of light output by each of the multiple light sources in association with position information of each light source. For example, the storage unit 103 stores size information of the underwater vehicle 100.

[0150] The acquiring unit 104 acquires various types of information and may store the acquired various types of information in the storage unit 103.

[0151] The acquisition unit 104 acquires information about the underwater vehicle 100 measured by sensors mounted on the underwater vehicle 100. The acquisition unit 104 acquires, for example, attitude information about the underwater vehicle 100. The acquisition unit 104 acquires, for example, water depth information indicating the water depth of the underwater vehicle 100.

[0152] The distance determination unit 106 determines the distance used to estimate the underwater position of the underwater vehicle 100. The distance determination unit 106 determines the distance used to estimate the underwater position of the underwater vehicle 100, for example, while the underwater vehicle 100 is performing an operation underwater.

[0153] The distance determination unit 106 determines the distance used to estimate the underwater position of the underwater vehicle 100, for example, based on the first captured image captured by the imaging unit 140. The distance determination unit 106, for example, performs distortion correction processing on the first captured image, and determines the distance used to estimate the underwater position of the underwater vehicle 100, based on the first captured image on which the distortion correction processing has been performed.

[0154] Distance determination unit 106 determines D1 based on, for example, a first captured image captured by imaging unit 140 of light 215 output from light source 210. For example, if imaging unit 140 is a stereo camera, distance determination unit 106 determines D1 based on the distance between two cameras constituting imaging unit 140, the focal lengths of the two cameras, and the parallax between the two cameras.

[0155] The distance determination unit 106 determines D1 based on, for example, a first captured image obtained by the imaging unit 140 capturing light 213 output from the light source unit 212 of the light source 210 and light 217 output from the light source unit 216 of the light source 210, and h1. The distance determination unit 106 determines D1 based on, for example, D1=(h1×f1) / (p D1 ×a D1 ) to determine D1.

[0156] The distance determination unit 106 determines L1 based on, for example, D1 and the first captured image. The distance determination unit 106 determines L1 based on, for example, L1=(p L1 ×a L1 Determine L1 using (×D1) / f1.

[0157] The distance determination unit 106 determines D1 based on, for example, the attitude information of the underwater vehicle 100 acquired by the acquisition unit 104. For example, the attitude information of the underwater vehicle 100 is determined based on the attitude information of the underwater vehicle 100 when the underwater vehicle 100 is in a position θ P If the distance indicates that the object is tilted by D 1c =(h1×f1) / (p D1 ×a D1 ) to D 1c Determine D1=D 1c ×cosθ P =(h1×f1) / (p D1 ×a D1 )×cosθ P D1 is determined using

[0158] For example, the attitude information of the underwater vehicle 100 is expressed as follows: Y If the distance indicates that the object is tilted by only D, the distance determination unit 106 determines D1 and L1 as follows. For example, the distance determination unit 106 determines D 1c =(h1×f1) / (p D1 ×a D1 ) to D 1c Determine L 1c =(p L1 ×a L1 ×D1) / f1 to L 1c Next, the distance determination unit 106 determines D' 1c ={(D 1c ) 2 +(L 1c ) 2} 1 / 2 Using D' 1c Determine θ1=arctan(L 1c / D 1c ) to determine θ1. Then, the distance determination unit 106 determines θ1 by using D1=D' 1c ×cos(θ Y±θ1) to determine D1, and L1 = {(D' 1c ) 2 -(D 1c ) 2} 1 / 2 Determine L1 using

[0159] The distance determination unit 106 determines the distance used to estimate the underwater position of the underwater vehicle 100, for example, based on the second captured image captured by the imaging unit 160. The distance determination unit 106, for example, performs distortion correction processing on the second captured image, and determines the distance used to estimate the underwater position of the underwater vehicle 100, based on the second captured image on which the distortion correction processing has been performed.

[0160] Distance determination unit 106 determines D2, for example, based on a second captured image captured by imaging unit 160 of light 225 output from light source 220. For example, if imaging unit 160 is a stereo camera, distance determination unit 106 determines D2 based on the distance between two cameras constituting imaging unit 160, the focal lengths of the two cameras, and the parallax between the two cameras.

[0161] The distance determination unit 106 may determine D2 in the same manner as when determining D1. The distance determination unit 106 may determine L2 in the same manner as when determining L1. The distance determination unit 106 may determine D 1c In the same way as when determining D 2c The distance determination unit 106 may determine L 1c In the same way as when determining L 2c The distance determination unit 106 may determine D' 1c In the same way as when determining D' 2c The distance determination unit 106 may determine θ2 in the same manner as when determining θ1.

[0162] The position estimation unit 108 estimates the underwater position of the underwater vehicle 100. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100 based on, for example, D1. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100 based on, for example, D2. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100 based on, for example, D1 and D2.

[0163] The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on L1. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on L2. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on L1 and L2.

[0164] The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the first captured image. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the second captured image. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the first captured image and the second captured image.

[0165] The position estimation unit 108, for example, performs image processing on the first captured image to acquire wavelength region information indicating the wavelength region of the light 215 output from the light source 210, and estimates the underwater position of the underwater vehicle 100 based further on the position information of the light source 210 stored in the storage unit 103 in association with the acquired wavelength region information of the light source 210. The position estimation unit 108, for example, performs image processing on the second captured image to acquire wavelength region information indicating the wavelength region of the light 225 output from the light source 220, and estimates the underwater position of the underwater vehicle 100 based further on the position information of the light source 220 stored in the storage unit 103 in association with the acquired wavelength region information of the light source 220. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100 based further on the position information of the light source 210 and the position information of the light source 220.

[0166] The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on size information of the underwater vehicle 100 stored in the storage unit 103. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on first length information of the underwater vehicle 100 included in the size information of the underwater vehicle 100. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on second length information of the underwater vehicle 100 included in the size information of the underwater vehicle 100. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the first length information and second length information of the underwater vehicle 100.

[0167] The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the attitude information of the underwater vehicle 100 acquired by the acquisition unit 104. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, based on the θ Y The underwater position of the underwater vehicle 100 is estimated based on the above.

[0168] The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the water depth information of the underwater vehicle 100 acquired by the acquisition unit 104. In this case, the position estimation unit 108 estimates the three-dimensional position of the underwater vehicle 100.

[0169] The communication unit 110 has a function of performing wireless communication. The communication unit 110 has a function of performing, for example, optical wireless communication. The communication unit 110 has a function of performing, for example, optical camera communication.

[0170] The communication unit 110 receives the identification information of the light source 210 from the light source 210, for example, by performing optical camera communication with the light source 210 using the imaging unit 140. The communication unit 110 receives the identification information of the light source 220 from the light source 220, for example, by performing optical camera communication with the light source 220 using the imaging unit 160.

[0171] The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the position information of the light source 210 that is stored in the storage unit 103 in association with the identification information of the light source 210. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the position information of the light source 220 that is stored in the storage unit 103 in association with the identification information of the light source 220. The position estimation unit 108 estimates the underwater position of the underwater vehicle 100, for example, further based on the position information of the light source 210 and the position information of the light source 220.

[0172] For example, when the underwater vehicle 100 is located underwater, the communication unit 110 performs optical wireless communication with the information processing device 350 located on the water surface. For example, when the underwater vehicle 100 is located underwater, the communication unit 110 performs optical camera communication with the information processing device 350 located on the water surface.

[0173] The communication unit 110 communicates optically wirelessly with the information processing device 350, for example, by transmitting various types of information to the information processing device 350. The communication unit 110 transmits various types of information to the information processing device 350, for example, by using the light source 170 to output light 175 that carries an optical signal including the various types of information.

[0174] The communication unit 110 transmits, for example, position information indicating the underwater position of the underwater vehicle 100 estimated by the position estimation unit 108 to the information processing device 350. The communication unit 110 may transmit any other information to the information processing device 350.

[0175] The communication unit 110 communicates optically wirelessly with the information processing device 350, for example, by receiving various information from the information processing device 350. The communication unit 110 communicates optically wirelessly with the information processing device 350, for example, by receiving light 375 output from the light source 370 using the light receiving unit 180.

[0176] The communication unit 110 receives, for example, control information for controlling the underwater vehicle 100 from the information processing device 350. The underwater vehicle 100 may control itself based on the control information received from the information processing device 350. The communication unit 110 may also receive any other information from the information processing device 350.

[0177] 12 shows an example of the functional configuration of the estimation device 400. The estimation device 400 includes a storage unit 403, an acquisition unit 404, a distance determination unit 406, a position estimation unit 408, a communication unit 410, an imaging unit 440, an imaging unit 460, a light source 470, and a light receiving unit 480. Note that it is not essential that the estimation device 400 include all of these components.

[0178] The storage unit 403 stores various types of information. The storage unit 403 may store the same information as the storage unit 103. The storage unit 403 may have the same functions as the storage unit 103.

[0179] The acquiring unit 404 acquires various types of information. The acquiring unit 404 may store the acquired various types of information in the storage unit 403.

[0180] The acquiring unit 404 may acquire the same information as the acquiring unit 104. The acquiring unit 404 may have the same functions as the acquiring unit 104.

[0181] The distance determination unit 406 determines the distance used to estimate the underwater position of the estimation device 400. The distance determination unit 406 determines the distance used to estimate the underwater position of the estimation device 400 in the same manner as when the distance determination unit 106 determines the distance used to estimate the underwater position of the underwater vehicle 100. The distance determination unit 406 may have the same function as the distance determination unit 106.

[0182] The position estimation unit 408 estimates the underwater position of the estimation device 400. The position estimation unit 408 estimates the underwater position of the estimation device 400 in the same manner as when the position estimation unit 108 estimates the underwater position of the underwater vehicle 100. The position estimation unit 408 may have the same functions as the position estimation unit 108.

[0183] The communication unit 410 has a function of wireless communication. The communication unit 410 may have the same function as the communication unit 110.

[0184] Fig. 13 is an explanatory diagram for explaining an example of the processing flow of the system 10. In Fig. 13, a state in which the underwater vehicle 100 is located in a space 50 surrounded by a plurality of light sources including a light source 210 and a light source 220 is taken as an initial state.

[0185] In step (sometimes abbreviated as S) 102, the image capturing section 140 captures an image of the light 215 output from the light source 210. In S104, the image capturing section 160 captures an image of the light 225 output from the light source 220.

[0186] In S106, the distance determination unit 106 determines the distance in the first direction from the underwater vehicle 100 to the light source 210 based on the first captured image captured by the imaging unit 140 in S102. The distance determination unit 106 determines the distance in the second direction from the underwater vehicle 100 to the light source 220 based on the second captured image captured by the imaging unit 160 in S104.

[0187] In S108, the position estimation unit 108 estimates the underwater position of the underwater vehicle 100 based on the distance in the first direction from the underwater vehicle 100 to the light source 210 and the distance in the second direction from the underwater vehicle 100 to the light source 220, which were determined by the distance determination unit 106 in S106. In S110, the communication unit 110 uses the light source 170 to transmit to the information processing device 350 position information indicating the underwater position of the underwater vehicle 100 estimated by the position estimation unit 108 in S108.

[0188] 14 schematically illustrates an example of the hardware configuration of a computer 1200 that functions as the underwater vehicle 100 or the estimation device 400. A program installed on the computer 1200 can cause the computer 1200 to function as one or more "parts" of the device according to the present embodiment, or can cause the computer 1200 to perform operations associated with the device according to the present embodiment or one or more "parts" thereof, and / or can cause the computer 1200 to perform a process according to the present embodiment or steps of the process. Such a program can be executed by the CPU 1212 to cause the computer 1200 to perform specific operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

[0189] The computer 1200 according to this embodiment includes a CPU 1212, a RAM 1214, and a graphics controller 1216, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communications interface 1222, a storage device 1224, a DVD drive 1226, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1220. The DVD drive 1226 may be a DVD-ROM drive, a DVD-RAM drive, or the like. The storage device 1224 may be a hard disk drive, a solid-state drive, or the like. The computer 1200 also includes a ROM 1230 and legacy input / output units such as a keyboard, which are connected to the input / output controller 1220 via an input / output chip 1240.

[0190] The CPU 1212 operates according to programs stored in the ROM 1230 and the RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires image data generated by the CPU 1212 into a frame buffer or the like provided in the RAM 1214 or into the graphics controller itself, and causes the image data to be displayed on the display device 1218.

[0191] The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD drive 1226 reads programs or data from a DVD-ROM 1227 or the like and provides them to the storage device 1224. The IC card drive reads programs and data from an IC card and / or writes programs and data to an IC card.

[0192] The ROM 1230 stores therein a boot program or the like that is executed by the computer 1200 upon activation, and / or programs that depend on the hardware of the computer 1200. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via a USB port, a parallel port, a serial port, a keyboard port, a mouse port, etc.

[0193] The programs are provided by a computer-readable storage medium such as a DVD-ROM 1227 or an IC card. The programs are read from the computer-readable storage medium, installed in the storage device 1224, RAM 1214, or ROM 1230, which are also examples of computer-readable storage media, and executed by the CPU 1212. Information processing described in these programs is read by the computer 1200, and causes cooperation between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing operations or processing of information in accordance with the use of the computer 1200.

[0194] For example, when communication is performed between the computer 1200 and an external device, the CPU 1212 may execute a communication program loaded into the RAM 1214 and instruct the communication interface 1222 to perform communication processing based on the processing described in the communication program. Under the control of the CPU 1212, the communication interface 1222 reads transmission data stored in a transmission buffer area provided in the RAM 1214, the storage device 1224, the DVD-ROM 1227, or a recording medium such as an IC card, and transmits the read transmission data to the network, or writes reception data received from the network to a reception buffer area or the like provided on the recording medium.

[0195] Furthermore, the CPU 1212 may cause all or a necessary portion of a file or database stored in an external recording medium such as the storage device 1224, the DVD drive 1226 (DVD-ROM 1227), an IC card, etc. to be read into the RAM 1214, and may perform various types of processing on the data on the RAM 1214. The CPU 1212 may then write back the processed data to the external recording medium.

[0196] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and may undergo information processing. The CPU 1212 may perform various types of processing on data read from the RAM 1214, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described throughout this disclosure and specified by the instruction sequences of the programs, and write the results back to the RAM 1214. The CPU 1212 may also search for information in a file, database, etc. on the recording medium. For example, if multiple entries, each having an attribute value of a first attribute associated with an attribute value of a second attribute, are stored on the recording medium, the CPU 1212 may search for an entry whose attribute value of the first attribute matches a specified condition from among the multiple entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0197] The above-described programs or software modules may be stored in a computer-readable storage medium on or near the computer 1200. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can also be used as a computer-readable storage medium, thereby providing the programs to the computer 1200 via the network.

[0198] The blocks in the flowcharts and block diagrams in the present embodiments may represent stages of a process in which an operation is performed or "parts" of an apparatus responsible for performing the operation. Particular stages and "parts" may be implemented by dedicated circuitry, programmable circuitry provided with computer-readable instructions stored on a computer-readable storage medium, and / or a processor provided with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuitry may include digital and / or analog hardware circuits, including integrated circuits (ICs) and / or discrete circuits. The programmable circuitry may include reconfigurable hardware circuits, such as field programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), including AND, OR, XOR, NAND, NOR, and other logical operations, flip-flops, registers, and memory elements.

[0199] A computer-readable medium may include any tangible device capable of storing instructions that are executed by a suitable device, such that the computer-readable medium having instructions stored thereon comprises an article of manufacture containing instructions that can be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of computer-readable media may include electronic, magnetic, optical, electromagnetic, and semiconductor storage media. More specific examples of computer-readable media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disc (DVD), Blu-ray disc, memory stick, integrated circuit card, and the like.

[0200] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, JAVA®, C++, etc., and conventional procedural programming languages ​​such as the “C” programming language or similar programming languages.

[0201] The computer-readable instructions may be provided to a processor or programmable circuit of a programmable data processing device, such as a computer, locally or via a wide area network (WAN) such as a local area network (LAN) or the Internet, and the computer-readable instructions may be executed to create means for performing the operations specified in the flowcharts or block diagrams. Here, the computer may be a personal computer (PC), a tablet computer, a smartphone, a workstation, a server computer, a general-purpose computer, a special-purpose computer, or the like, or may be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system, and is a broad definition of computer. In a distributed computing system, the multiple computers collectively execute a program by each executing a portion of the program and passing data between the computers as needed during program execution.

[0202] Examples of processors include a computer processor, a central processing unit (CPU), a processing unit, a microprocessor, a digital signal processor, a controller, a microcontroller, etc. A computer may have one or more processors. In a multiprocessor system with multiple processors, each processor executes a portion of a program and passes data between processors as needed during program execution, allowing the multiple processors to collectively execute the program. For example, in multitasking, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at time slice intervals. In this case, which portion of a program each processor executes changes dynamically. Which portion of a program each of the multiple processors executes may also be statically determined by multiprocessor-aware programming.

[0203] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0204] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0205] 10 System, 50 Space, 100 Underwater Vehicle, 102 Main Body, 103 Storage Section, 104 Acquisition Section, 106 Distance Determination Section, 108 Position Estimation Section, 110 Communication Section, 140 Imaging Section, 142 Imaging Range, 145 Lens, 148 Imaging Element, 160 Imaging Section, 162 Imaging Range, 170 Light Source, 175 Light, 180 Light Receiving Section, 190 Mounting Section, 210 Light Source, 212 Light Source Unit, 213 Light, 215 Light, 216 Light Source Unit, 217 Light, 219 Cable, 220 Light Source, 222 Light Source Unit, 223 Light, 225 Light, 226 Light Source Unit, 227 Light, 229 Cable, 251 Light Source, 252 Light Source, 253 Light Source, 254 Light Source, 255 Light source, 256, light source, 257, light source, 261, light source, 262, light source, 263, light source, 264, light source, 265, light source, 266, light source, 267, light source, 300, ship, 350, information processing device, 370, light source, 375, light, 380, light receiving unit, 390, mounted unit, 400, estimation device, 402, main body, 403, storage unit, 404, acquisition unit, 406, distance determination unit, 408, position estimation unit, 410, communication unit, 422, float, 424, weight, 440, imaging unit, 442, imaging range, 460, imaging unit, 462, imaging range, 470, light source, 480, light receiving unit, 490, mounted unit, 500, user, 550, tether, 580, cylinder, 1200, computer, 1210 Host controller, 1212 CPU, 1214 RAM, 1216 graphics controller, 1218 display device, 1220 input / output controller, 1222 communication interface, 1224 storage device, 1226 DVD drive, 1227 DVD-ROM, 1230 ROM, 1240 input / output chip, 1481 photodetector, 1482 photodetector, 1483 photodetector

Claims

1. An underwater vehicle, a first imaging unit that captures an image of a first imaging range; a second imaging unit that captures an image of a second imaging range different from the first imaging range; a distance determination unit that determines a first distance in a first direction from the underwater vehicle to a first light source based on a first captured image of light output from the first light source located underwater, captured by the first imaging unit, and determines a second distance in a second direction from the underwater vehicle to the second light source based on a second captured image of light output from a second light source different from the first light source located underwater, captured by the second imaging unit; a position estimation unit that estimates the underwater position of the underwater vehicle based on the first distance and the second distance; An underwater vehicle comprising:

2. the distance determiner determines the first distance based on the first captured image captured by the first imager of the light output from the first light source unit of the first light source and the light output from the second light source unit of the first light source, and a light source unit interval in a third direction perpendicular to the first direction between the first light source unit and the second light source unit. The underwater vehicle according to claim 1 .

3. The distance determiner determines the first distance using the following formula: D １ =(h １ ×f １ ) / (p Ｄ１ ×a Ｄ１ ) Here, D １ is the first distance, and h １ is the light source unit interval, and f １ is the focal length of the lens of the first imaging unit, and p Ｄ１ is the number of light receiving elements of the first imaging unit present between a first light receiving element of the first imaging unit that receives light output from the first light source unit and a second light receiving element of the first imaging unit that receives light output from the second light source unit in a fourth direction corresponding to the third direction, and a Ｄ１ is the length in the fourth direction of one light receiving element of the first imaging unit, The underwater vehicle according to claim 2.

4. the distance determiner determines a third distance in a fifth direction perpendicular to the first direction and the third direction from the underwater vehicle to the first light source based on the first distance and the first captured image; the position estimation unit estimates the underwater position of the underwater vehicle further based on the third distance. The underwater vehicle according to claim 2.

5. The distance determiner determines the third distance using the following formula: L １ =(p Ｌ１ ×a Ｌ１ ×D １ ) / f １ Here, L １ is the third distance, and p Ｌ１ is the number of light receiving elements of the first imaging unit present between a first light receiving element of the first imaging unit that receives light output from the first light source unit in a sixth direction corresponding to the fifth direction and a center line of the imaging element of the first imaging unit including the first light receiving element that is perpendicular to a line parallel to the sixth direction, and a Ｌ１ is the length of one light receiving element of the first imaging unit in the sixth direction, and D １ is the first distance, and f １ is the focal length of the lens of the first imaging unit, The underwater vehicle according to claim 4.

6. 6. The underwater vehicle described in any one of claims 1 to 5, wherein the first imaging unit is mounted on a first surface of the main body of the underwater vehicle, and the second imaging unit is mounted on a second surface of the main body of the underwater vehicle opposite to the first surface.

7. an acquisition unit that acquires attitude information indicating the attitude of the underwater vehicle; Furthermore, The distance determiner determines the first distance further based on the attitude information of the underwater vehicle.

6. An underwater vehicle according to any one of claims 1 to 5.

8. a storage unit for storing size information indicating the size of the underwater vehicle; Furthermore, the position estimation unit estimates the underwater position of the underwater vehicle further based on the size information.

6. An underwater vehicle according to any one of claims 1 to 5.

9. a storage unit that stores identification information of the first light source and position information indicating a position where the first light source is disposed in association with each other, and that stores identification information of the second light source and position information indicating a position where the second light source is disposed in association with each other; a communication unit that receives the identification information of the first light source from the first light source by optical camera communication (OCC) with the first light source using the first imaging unit, and receives the identification information of the second light source from the second light source by optical camera communication with the second light source using the second imaging unit; Furthermore, the position estimation unit estimates the underwater position of the underwater vehicle further based on the position information of the first light source stored in the storage unit in association with the identification information of the first light source and the position information of the second light source stored in the storage unit in association with the identification information of the second light source.

6. An underwater vehicle according to any one of claims 1 to 5.

10. a communication unit that transmits, to an information processing device located on the surface of the water, position information indicating the underwater position of the underwater vehicle estimated by the position estimation unit by optical wireless communication with the information processing device located on the surface of the water while the underwater vehicle is located underwater. The underwater vehicle according to claim 1 , further comprising:

11. An underwater vehicle according to any one of claims 1 to 5; a plurality of light sources including the first light source and the second light source and disposed underwater; A location estimation system comprising:

12. the plurality of light sources are arranged underwater so that, when the underwater vehicle is located in a space surrounded by the plurality of light sources, the first imaging unit can image light output from one of the plurality of light sources, and the second imaging unit can image light output from another light source different from the one light source among the plurality of light sources; The location estimation system of claim 11 .

Images