An underwater robot navigation device and method
By combining laser and lens modules based on photoelectric principles, the displacement and velocity of underwater robots are calculated, solving the problems of high cost and low accuracy in existing technologies, and realizing efficient and low-cost underwater navigation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-07
- Publication Date
- 2026-03-10
AI Technical Summary
Existing underwater robot positioning technologies suffer from high costs, low accuracy, and error accumulation, making them particularly unsuitable for navigation tasks in small bodies of water such as swimming pools.
Using photoelectric principles, the robot's displacement and velocity information relative to the plane are acquired through a laser emission module, a lens module, and an optical sensor module. The robot's displacement and velocity are then calculated by performing cross-correlation calculations using a digital signal processing module.
It reduces the cost of underwater navigation and positioning, improves positioning accuracy, does not rely on underwater communication devices, avoids error accumulation, and achieves high-precision navigation.
Smart Images
Figure CN115900727B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of robot positioning and navigation technology, and in particular to an underwater robot navigation device and method. Background Technology
[0002] As people's living standards continue to improve, swimming pools are increasingly found in private courtyards and upscale residential areas. After a period of use, a layer of grime accumulates on the bottom and sides of the pool, making it difficult to clean thoroughly. Compared to manual cleaning, using an automated pool cleaning robot can achieve zero blind spots, convenience, and low cost. To improve the cleaning efficiency and intelligence of the pool robot, it is necessary to obtain the robot's motion navigation and positioning information during its movement.
[0003] Currently, there are three main technical solutions used for underwater positioning:
[0004] 1. Inertial navigation-based positioning. This method calculates the robot's relative displacement using inertial sensors (including accelerometers and gyroscopes). However, this approach often relies on complex algorithms, cannot guarantee navigation accuracy, and suffers from cumulative errors, making it unsuitable for extended underwater operations.
[0005] 2. Sonar-based positioning. Electromagnetic signals attenuate rapidly in water, making distance measurement impossible as in air using ultrasound or infrared. However, navigation and positioning information can be obtained using sonar generators and receivers. Underwater acoustic positioning is commonly used in areas such as waterway safety, mineral resource surveys, and submarine cable laying. This method is relatively expensive and not suitable for navigation in small bodies of water environments such as swimming pools.
[0006] 3. GPS-based underwater positioning. This method requires the use of multiple GPS buoys. The underwater navigation transceiver sends positioning signals to the GPS buoys, which then modulate the underwater acoustic positioning signals, buoy attitude calibration data, and GPS signals before sending them to the data control center. The data control center fuses the differential signals from the GPS base station with the above information to calculate the underwater target position. This method is costly and has low accuracy, requiring the pre-installation of multiple GPS buoys, making it unsuitable for navigation tasks in swimming pool environments.
[0007] In summary, the shortcomings of existing technical solutions are mainly as follows:
[0008] 1. The beacon method requires advance deployment and is not convenient;
[0009] 2. The underwater acoustic solution is costly and not suitable for use in small areas such as swimming pools;
[0010] 3. Inertial navigation has low accuracy and large cumulative error, making it unreliable in engineering applications.
[0011] Therefore, those skilled in the art are dedicated to developing an underwater robot navigation device and method. Summary of the Invention
[0012] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is how to reduce the cost of underwater navigation and positioning and improve the positioning accuracy.
[0013] The inventors discovered through research that by using photoelectric principles, by taking continuous images of the surface and comparing the differences between adjacent images, the displacement and velocity information of the robot relative to the plane can be calculated. This allows the robot to obtain its own displacement and velocity information without relying on underwater communication devices.
[0014] In one embodiment of the present invention, an underwater robot navigation device is provided, comprising:
[0015] The laser emitting module emits concentric laser beams toward the bottom surface of the pool.
[0016] The lens module includes a refractive sub-module and a converging sub-module. The refractive sub-module is located between the laser emitting module and the bottom surface of the pool. It increases the brightness of the concentric laser beam emitted by the laser emitting module and refracts it into a parallel laser beam that is directed toward the bottom surface of the pool. The converging sub-module is located between the bottom surface of the pool and the optical sensor module. The parallel laser beam reflected by the bottom surface of the pool is converged into a concentric laser beam by the converging sub-module and then transmitted to the optical sensor module.
[0017] The optical sensor module is equipped with uniformly arranged tiny photosensitive materials that receive the concentric laser beams converged by the lens module and convert them into electrical signals that are proportional to the optical signals, thus forming an image array.
[0018] The digital signal processing module includes a digital image chip, which is communicatively connected to the optical sensor module. In response to the image array sent by the optical sensor module, it performs cross-correlation calculations to obtain the variation values of the X-axis and Y-axis directions of two consecutive image arrays in pixels. By converting pixels to actual physical distance, displacement and velocity information are obtained.
[0019] The power management module is connected to and supplies power to the laser emission module, optical sensor module, and digital signal processing module.
[0020] The power management module supplies power, and the laser emitting module emits a concentric laser beam. The beam is refracted into a parallel laser beam by the refraction submodule of the lens module and directed toward the bottom surface of the pool. The parallel laser beam reflected from the bottom surface of the pool is then converged into a concentric laser beam by the convergence submodule of the lens module and transmitted to the optical sensor module to form an image array. The image array is then transmitted to the digital signal processing module for cross-correlation calculations to finally obtain displacement and velocity information.
[0021] Optionally, in the underwater robot navigation device of the above embodiments, a parallel laser beam illuminates the bottom surface of the pool at a certain angle.
[0022] Furthermore, in the underwater robot navigation device of the above embodiments, the angle is preferably between 15-45°.
[0023] Furthermore, in the underwater robot navigation device of the above embodiment, the illuminated bottom surface area of the pool is approximately 5 square millimeters.
[0024] Optionally, in the underwater robot navigation device of any of the above embodiments, a black base plate is provided between the lens module and the power management module, laser emission module, optical sensor module, and digital signal processing module to prevent light interference.
[0025] Optionally, in the underwater robot navigation device of any of the above embodiments, the optical sensor module is provided with a light-transmitting hole to receive the concentric laser beam converged by the converging submodule of the lens module. The light-transmitting hole is provided with a waterproof gasket to protect the internal circuit structure.
[0026] Optionally, in the underwater robot navigation device of any of the above embodiments, the image array is 40x40 pixels in size, and each pixel consists of gray levels in the range of 0-4095. The gray level is determined by the light intensity received at a specific pixel position in the optical sensor module.
[0027] Alternatively, in the underwater robot navigation device of any of the above embodiments, the refractive submodule uses a prism.
[0028] Optionally, in the underwater robot navigation device of any of the above embodiments, the refractive submodule uses a convex lens spherical surface, and the number of reflecting planes is one to three, which is selected according to different light guiding schemes.
[0029] Alternatively, in the underwater robot navigation device of any of the above embodiments, the converging submodule uses a circular lens.
[0030] The inventors connected the underwater robot navigation device of the above embodiment to the underwater robot control board to provide the robot with the displacement and speed information required for navigation.
[0031] Based on any of the above embodiments, in another embodiment of the present invention, an underwater robot is provided, which is communicatively connected to the underwater robot navigation device in any of the above embodiments, and receives and responds to the displacement and velocity information of the underwater robot navigation device.
[0032] Based on any of the above embodiments, another embodiment of the present invention provides an underwater robot navigation method, comprising the following steps:
[0033] S100, installation of underwater robot navigation device;
[0034] S200, the underwater robot is started. The underwater robot is placed in the pool, and the underwater robot and its navigation device begin to work.
[0035] S300, image array acquisition: the laser emission module emits concentric laser beams toward the bottom surface of the pool, which are reflected and converged by the lens module to form an image array on the optical sensor module;
[0036] S400, displacement and velocity calculation: The digital signal processing module receives the image array and performs cross-correlation calculation. It continuously moves the coordinate position of the next frame image array while keeping the previous frame image array fixed. It compares the difference between the two image arrays. When the difference is the smallest, it is considered as the change value of the adjacent two image arrays in the X-axis and Y-axis directions in pixels. Through the conversion between pixels and actual physical distance, displacement and velocity information are obtained.
[0037] S500: Navigation information transmission. The digital signal processing module sends displacement and velocity information to the underwater robot for navigation.
[0038] S600, navigation information response: the underwater robot receives and responds to displacement and velocity information.
[0039] Optionally, in the underwater robot navigation method of the above embodiments, step S100 includes:
[0040] S110. Install the underwater robot navigation device on the bottom of the underwater robot. The bottom of the underwater robot navigation device should be close to the bottom surface of the pool, with a maximum gap of 1 mm.
[0041] S120 connects the underwater robot navigation device and the underwater robot via a USB cable, transmitting navigation data and providing power.
[0042] Optionally, in the underwater robot navigation method of any of the above embodiments, the image array in step S300 is 40x40 pixels in size, and each pixel is composed of gray levels in the range of 0-4095. The gray level is determined by the light intensity received at a specific pixel position in the optical sensor module.
[0043] Optionally, in the underwater robot navigation method of any of the above embodiments, step S300 includes:
[0044] S310, laser emission: The laser emission module emits concentric laser beams toward the bottom surface of the pool.
[0045] S320, Lens module refraction: The refraction sub-module of the lens module increases the brightness of the concentric laser beam emitted by the laser emission module and refracts it into a parallel laser beam that is directed at the bottom surface of the pool at a certain angle.
[0046] S330, Reflection at the bottom surface of the pool: The bottom surface of the pool reflects the parallel laser beam.
[0047] S340, the lens module converges the parallel laser beams reflected from the bottom surface of the pool into a concentric laser beam through the converging sub-module of the lens module, and then transmits it to the optical sensor module.
[0048] S350, Image Array Formation: The optical sensor module receives the concentric laser beams converged by the converging submodule and converts them into electrical signals proportional to the optical signals, thus forming an image array.
[0049] Furthermore, in the underwater robot navigation method of the above embodiments, the angle in step S320 is preferably between 15-45°.
[0050] This invention does not rely on underwater communication devices, allowing underwater robots to acquire their own displacement and velocity information, thus reducing the cost of underwater navigation and positioning. It also improves positioning accuracy by not relying on underwater communication equipment and eliminates the need to consider the accuracy degradation caused by error accumulation. The chip and sensor materials of this invention are readily available and inexpensive. Furthermore, this invention has its own laser emitter, which is unaffected by visible light and provides high accuracy.
[0051] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description
[0052] Figure 1 This is a schematic diagram of the structure of an underwater robot navigation device according to an exemplary embodiment;
[0053] Figure 2 This is a flowchart illustrating an underwater robot navigation method according to an exemplary embodiment. Detailed Implementation
[0054] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.
[0055] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of components is schematically exaggerated in some places in the drawings.
[0056] The inventor designed an underwater robot navigation device, such as Figure 1 As shown, it includes:
[0057] The laser emitting module emits concentric laser beams toward the bottom surface of the pool.
[0058] The lens module includes a refractive sub-module and a converging sub-module. The refractive sub-module is located between the laser emitting module and the bottom surface of the water tank. It increases the brightness of the concentric laser beam emitted by the laser emitting module and refracts it into a parallel laser beam that is directed towards the bottom surface of the water tank. The parallel laser beam illuminates the bottom surface of the water tank at a certain angle, preferably between 15-45°, illuminating an area of approximately 5 square millimeters. The converging sub-module is located between the bottom surface of the water tank and the optical sensor module. The parallel laser beam reflected from the bottom surface of the water tank is converged into a concentric laser beam by the converging sub-module and then transmitted to the optical sensor module. A black base plate is installed between the lens module and the power management module, laser emitting module, optical sensor module, and digital signal processing module to prevent light interference. The refractive sub-module uses a prism, and the converging sub-module uses a circular lens. The refractive sub-module can also use a convex spherical lens, with one to three reflecting planes, selected according to different light guiding schemes.
[0059] The optical sensor module contains uniformly arranged tiny photosensitive materials that receive a concentric laser beam converged by the lens module. This beam is converted into an electrical signal proportional to the optical signal, forming an image array. The image array is 40x40 pixels in size, with each pixel consisting of gray levels ranging from 0 to 4095. The gray level is determined by the light intensity received at a specific pixel location within the optical sensor module. The optical sensor module also features a light-transmitting aperture through which it receives the concentric laser beam converged by the lens module's focusing sub-module. A waterproof gasket is installed in the aperture to protect the internal circuitry.
[0060] The digital signal processing module includes a digital image chip, which is communicatively connected to the optical sensor module. In response to the image array sent by the optical sensor module, it performs cross-correlation calculations to obtain the variation values of the X-axis and Y-axis directions of two consecutive image arrays in pixels. By converting pixels to actual physical distance, displacement and velocity information are obtained.
[0061] The power management module is connected to and supplies power to the laser emission module, optical sensor module, and digital signal processing module.
[0062] The power management module supplies power, and the laser emitting module emits a concentric laser beam. The beam is refracted into a parallel laser beam by the refraction submodule of the lens module and directed toward the bottom surface of the pool. The parallel laser beam reflected from the bottom surface of the pool is then converged into a concentric laser beam by the convergence submodule of the lens module and transmitted to the optical sensor module to form an image array. The image array is then transmitted to the digital signal processing module for cross-correlation calculations to finally obtain displacement and velocity information.
[0063] The inventors connected the underwater robot navigation device of the above embodiment to the underwater robot control board to provide the robot with the displacement and speed information required for navigation.
[0064] Based on the above embodiments, in another embodiment of the present invention, an underwater robot is provided, which is communicatively connected to the underwater robot navigation device in the above embodiments, and receives and responds to the displacement and speed information of the underwater robot navigation device.
[0065] Based on the above embodiments, the inventors provide an underwater robot navigation method, such as... Figure 2 As shown, it includes the following steps:
[0066] S100, installation of underwater robot navigation device; including:
[0067] S110. Install the underwater robot navigation device on the bottom of the underwater robot. The bottom of the underwater robot navigation device should be close to the bottom surface of the pool, with a maximum gap of 1 mm.
[0068] S120 connects the underwater robot navigation device and the underwater robot via a USB cable, transmitting navigation data and providing power.
[0069] S200, the underwater robot is started. The underwater robot is placed in the pool, and the underwater robot and its navigation device begin to work.
[0070] S300, image array acquisition: The laser emitting module emits a concentric laser beam onto the bottom surface of the pool. The beam is reflected and converged by the lens module, forming an image array on the optical sensor module. The image array is 40x40 pixels in size, with each pixel consisting of gray levels ranging from 0 to 4095. The gray level is determined by the light intensity received at a specific pixel location within the optical sensor module. This includes:
[0071] S310, laser emission: The laser emission module emits concentric laser beams toward the bottom surface of the pool.
[0072] S320, Lens Module Refraction: The refraction submodule of the lens module increases the brightness of the concentric laser beam emitted by the laser emission module and refracts it into a parallel laser beam that is emitted at a certain angle.
[0073] The angle towards the bottom surface of the pool is preferably between 15-45°.
[0074] S330, Reflection at the bottom surface of the pool: The bottom surface of the pool reflects the parallel laser beam.
[0075] S340, the lens module converges the parallel laser beams reflected from the bottom surface of the pool into a concentric laser beam through the converging sub-module of the lens module, and then transmits it to the optical sensor module.
[0076] S350, Image Array Formation: The optical sensor module receives the concentric laser beam converged by the focusing submodule and converts it into an electrical signal proportional to the optical signal, forming...
[0077] Image array.
[0078] S400, displacement and velocity calculation: The digital signal processing module receives the image array and performs cross-correlation calculation. It continuously moves the coordinate position of the next frame image array while keeping the previous frame image array fixed. It compares the difference between the two image arrays. When the difference is the smallest, it is considered as the change value of the adjacent two image arrays in the X-axis and Y-axis directions in pixels. Through the conversion between pixels and actual physical distance, displacement and velocity information are obtained.
[0079] S500: Navigation information transmission. The digital signal processing module sends displacement and velocity information to the underwater robot for navigation.
[0080] S600, navigation information response: the underwater robot receives and responds to displacement and velocity information.
[0081] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.
Claims
1. An underwater robotic navigation apparatus, characterized by, The underwater robot navigation device comprises a laser emission module, a lens module, an optical sensor module, a digital signal processing module and a power management module. The laser emission module emits a concentric laser beam to the bottom surface of the pool. The lens module comprises a refraction sub-module and a converging sub-module. The refraction sub-module is located between the laser emission module and the bottom surface of the pool. The refraction sub-module improves the brightness of the concentric laser beam emitted by the laser emission module and refracts the concentric laser beam into a parallel laser beam. The converging sub-module is located between the bottom surface of the pool and the optical sensor module. The parallel laser beam reflected by the bottom surface of the pool is converged into a concentric laser beam by the converging sub-module and then transmitted to the optical sensor module.
2. The underwater robotic navigation apparatus of claim 1, wherein, The optical sensor module is provided with uniformly arranged micro photosensitive substances.
3. The underwater robotic navigation apparatus of claim 1, wherein, The optical sensor module receives the concentric laser beam converged by the lens module and converts the concentric laser beam into an electrical signal in a corresponding proportional relationship with an optical signal to form an image array.
4. The underwater robotic navigation apparatus of claim 1, wherein, The digital signal processing module comprises a digital image chip.
5. The underwater robotic navigation apparatus of claim 1, wherein, The digital signal processing module is communicatively connected with the optical sensor module.
6. The underwater robotic navigation apparatus of claim 1, wherein, The digital signal processing module performs cross-correlation operation in response to the image array sent by the optical sensor module.
7. An underwater robot, characterized in that, The digital signal processing module obtains the variation values of X-axis direction and Y-axis direction of two continuous image arrays in units of pixels.
8. A method of navigating an underwater robot using the underwater robot navigation apparatus according to any one of claims 1 to 6, characterized by, The digital signal processing module converts the pixels and actual physical distances to obtain displacement and speed information. The power management module is circuit-connected and powered for the laser emission module, the optical sensor module and the digital signal processing module. The power management module supplies power. The laser emission module emits a concentric laser beam. The concentric laser beam is refracted into a parallel laser beam by the refraction sub-module of the lens module. The parallel laser beam reflected by the bottom surface of the pool is converged into a concentric laser beam by the converging sub-module of the lens module. The concentric laser beam is transmitted to the optical sensor module to form the image array. The image array is transmitted to the digital signal processing module to perform cross-correlation operation. The final displacement and speed information are obtained. The lens module, the power management module, the laser emission module, the optical sensor module and the digital signal processing module are separated by a black bottom plate to prevent light interference. The optical sensor module is provided with a light transmission hole. The concentric laser beam converged by the converging sub-module of the lens module is received through the light transmission hole. The light transmission hole is provided with a waterproof gasket to protect the internal circuit structure. The size of the image array is 40x40 pixels. Each pixel is composed of a gray scale in the range of 0-4095. The gray scale is determined by the light intensity received by a specific pixel position in the optical sensor module. The refraction sub-module uses a prism. The converging sub-module uses a circular lens. The underwater robot navigation device is communicatively connected with the underwater robot. The underwater robot navigation device receives and responds to the displacement and speed information of the underwater robot. The underwater robot navigation device comprises the following steps. S100, the underwater robot navigation device is installed. S200, the underwater robot is started. The underwater robot is put into the pool. The underwater robot and the underwater robot navigation device start to work. S300, image array acquisition, the laser emission module emits a concentric laser beam to the pool bottom surface, the laser beam is reflected and converged by the lens module, and an image array is formed on the optical sensor module; S400, displacement and speed calculation, the digital signal processing module receives the image array and performs cross-correlation operation, the coordinate position of the next frame image array is constantly moved, the previous frame image array remains fixed, the difference between the two image arrays is compared, when the difference is the smallest, it is determined that the adjacent two image arrays change in the X-axis direction and the Y-axis direction by pixel, the displacement and speed information are obtained through the conversion between pixel and actual physical distance; S500, navigation information sending, the digital signal processing module sends the displacement and speed information to the underwater robot for navigation; S600, navigation information response, the underwater robot receives and responds to the displacement and speed information.
9. The method of navigating an underwater robot of claim 8, wherein, The step S100 comprises: S110, installing the underwater robot navigation device on the bottom of the underwater robot, the bottom of the underwater robot navigation device is close to the pool bottom surface, and the maximum interval cannot exceed 1mm; S120, connecting the underwater robot navigation device and the underwater robot through the USB connection line, transmitting navigation data and providing power supply.
10. The method of navigation for an underwater robot of claim 8, wherein, The step S300 comprises: S310, laser emission, the laser emission module emits a concentric laser beam to the pool bottom surface; S320, lens module refraction, the refraction sub-module of the lens module improves the brightness of the concentric laser beam emitted by the laser emission module, and refracts the concentric laser beam into parallel laser beams which are emitted to the pool bottom surface at a certain angle; S330, pool bottom surface reflection, the pool bottom surface reflects the parallel laser beams; S340, lens module convergence, the parallel laser beams reflected by the pool bottom surface are converged into a concentric laser beam by the convergence sub-module of the lens module, and are transmitted to the optical sensor module; S350, image array formation, the optical sensor module receives the concentric laser beam converged by the convergence sub-module, converts it into an electrical signal in a corresponding proportional relationship with an optical signal, and forms the image array.
Citation Information
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