Underwater observation, mapping and communication integrated optical system based on light source sharing

Abstract

This invention discloses an integrated underwater observation, mapping, and communication optical system based on shared light source, comprising a shared light source module for outputting laser light; an optical beam splitter module for splitting the laser light into two beams; a shared branch for forward-looking observation and laser communication, used to scan and image the target area in forward-looking observation mode based on the first laser beam, and to transmit laser communication signals and receive beacon light signals and laser communication signals in laser communication mode; a downward-looking mapping branch for scanning and imaging the underwater terrain based on the second laser beam; and a resource scheduling and signal processing module for mode management and resource scheduling according to task requirements, collaborative and closed-loop control of various modules, and processing of multi-source information. This invention has the advantages of reducing equipment redundancy, reducing system size and weight, avoiding signal interference, improving light source reuse efficiency, and enhancing task execution reliability.

Description

Technical Field

[0001] This invention belongs to the field of underwater optical technology, specifically relating to an integrated underwater observation, mapping and communication optical system based on light source sharing, which is applied to an underwater robot platform with autonomous navigation and operation capabilities. Background Technology

[0002] With the development of fields such as marine resource exploration and underwater pipeline inspection, autonomous underwater robots are undertaking increasingly diverse tasks in complex underwater environments. They often need to possess multiple capabilities such as underwater navigation and obstacle avoidance, terrain mapping, and high-speed data communication in order to perceive the environment in real time, build maps of the work area, and transmit the collected data back to the communication node in a timely manner.

[0003] Currently, most underwater robots employ discrete devices to perform the aforementioned functions. For example, high-definition cameras and corresponding lighting sources are used for forward observation and obstacle avoidance, laser scanners are used for downward terrain mapping, and laser communication modules are used for data transmission with the water surface or other nodes. This discrete arrangement, where each functional module typically has its own independent light source, optical front end, and drive control circuit, results in problems such as large size and weight, high power consumption and cost, and competition and interference for optical frequency resources, thus limiting the overall system performance.

[0004] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the aforementioned background technology and provide an integrated optical system for underwater observation, mapping, and communication based on shared light sources. This system can reduce equipment redundancy, decrease system size and weight, avoid signal interference, and simultaneously improve light source reuse efficiency and mission execution reliability.

[0006] The technical solution adopted in this invention is: an integrated optical system for underwater observation, mapping, and communication based on shared light source, comprising: A shared light source module is used to output laser light; An optical beam splitter module is used to split the laser into two laser beams; The forward-looking observation and laser communication share a branch, which is used to scan and image the target area based on the first laser beam output by the optical beam splitter module in the forward-looking observation mode, and to transmit laser communication signals and receive beacon light signals and laser communication signals in the laser communication mode. The downward-looking mapping branch is used to scan and image underwater terrain based on the second laser beam output by the optical beam splitter module; The resource scheduling and signal processing module is electrically connected to the shared light source module, the optical beam splitting module, the forward-looking observation and laser communication shared branch, and the downward-looking mapping branch, respectively. It is used to perform mode management and resource scheduling according to task requirements, coordinate and close-loop control of each module, and process multi-source information.

[0007] Furthermore, the shared light source module includes a laser for outputting laser light with a wavelength located in the low-attenuation band underwater.

[0008] Furthermore, the optical beam splitting module includes a beam splitter with an adjustable splitting ratio. The splitting ratio of the beam splitter is controlled by the resource scheduling and signal processing module, which can dynamically adjust the optical power distribution ratio of the forward observation and laser communication shared branch and the downward mapping branch according to the current task requirements.

[0009] Furthermore, the shared branch for forward-looking observation and laser communication includes: An external modulator is disposed on the optical path of the first laser beam. It is used to be in a direct state in forward-looking observation mode and to load the data signal of the resource scheduling and signal processing module in laser communication mode to modulate the first laser beam to form a communication carrier carrying information. The beam shaping and scanning unit is used to shape the unmodulated first laser beam into a fan-shaped illumination beam and perform one-dimensional spatial scanning in forward-looking observation mode, and to shape the communication carrier into a directional beam and point it toward the communication node in laser communication mode. The imaging detection module consists of a first imaging optical module and a first underwater camera. It is used to receive and image the scanning beam reflected by the target in forward-looking observation mode, and to receive the beacon light signal emitted by the communication node in laser communication mode to assist in beam alignment. The communication receiving unit is used to receive and demodulate laser communication signals from the communication node.

[0010] Furthermore, the beam shaping and scanning unit includes a first beam expanding optical module, a first beam shaping optical module, a reflector, and a scanning optical module arranged sequentially along the optical path. In forward-looking observation mode, the first beam expanding optical module is used to adjust the diameter of the first laser beam to reduce the divergence angle and form a collimated laser beam. The first shaping optical module shapes the collimated laser beam into a fan-shaped illumination beam with a certain divergence angle. The fan-shaped illumination beam is reflected by a mirror and guided to the scanning optical module. Under the control of the resource scheduling and signal processing module, the scanning optical module performs deflection motion so that the fan-shaped illumination beam performs one-dimensional scanning within a preset two-dimensional field of view, thereby illuminating the forward-looking area line by line. In laser communication mode, the resource scheduling and signal processing module controls the first shaping optical module to move out of the optical path. The first beam expanding optical module is used to adjust the diameter of the communication carrier to reduce the divergence angle and form a collimated communication carrier. The collimated communication carrier is guided to the scanning optical module after being reflected by the mirror. The scanning optical module performs deflection movement under the control of the resource scheduling and signal processing module so that the collimated communication carrier points to the communication node.

[0011] Furthermore, the communication receiving unit includes a communication receiving optical module and a photodetector. The communication receiving optical module is used to receive the laser communication signal emitted by the communication node and focus it onto the photodetector. The photodetector is used to convert the laser communication signal into an electrical signal and output it to the resource scheduling and signal processing module.

[0012] Furthermore, the downward-looking mapping branch includes a second beam-expanding optical module, a second shaping optical module, and a downward-looking imaging module arranged sequentially along the optical path; The second beam expander optical module is used to adjust the diameter of the second laser beam to reduce the divergence angle and form a collimated laser beam; The second shaping optical module is used to shape the collimated laser beam into a vertically downward fan-shaped light plane, which intersects with the seabed to form a scanning line; The downward-looking imaging module consists of imaging optical equipment and an underwater camera, and is used to capture images containing the scan lines.

[0013] Furthermore, the mode management and resource scheduling based on task requirements includes: The optical power distribution ratio of the optical beam splitter module is controlled according to external instructions or preset strategies; Switch the working mode of the shared branch of forward observation and laser communication to perform time-sharing or power-sharing work scheduling among the three functional modes of forward observation, laser communication and downward mapping. During mode switching, the corresponding optical path components are switched in or out, and the external modulator is started, stopped, and its working status is controlled to construct the physical optical path and signal path required for the current task.

[0014] Furthermore, the coordinated and closed-loop control of each module includes: In modes requiring coordinated scanning and imaging, a synchronization timing signal is generated and sent to coordinate the working timing of the light source, scanning, imaging, and modulation modules, ensuring precise synchronization between the beam scanning action and the detector exposure / acquisition action. Control commands are generated based on feedback information to dynamically adjust the actuators, including fine-tuning the scanning optical module based on beacon light images from the communication node fed back by the imaging detection module, so as to achieve precise alignment control of the communication beam.

[0015] Furthermore, the processing of multi-source information includes: The raw images or photoelectric signals collected by each module are processed to output structured information that can be used by the task. The processing includes generating observation images, demodulating communication data, and stitching together three-dimensional terrain data.

[0016] The beneficial effects of this invention are as follows: This invention outputs laser light through a shared light source module, which is then split by an optical beam splitter to drive the forward-looking observation and laser communication shared branch and the downward-looking mapping branch to work collaboratively. Mode management and resource scheduling are achieved by a resource scheduling and signal processing module, offering the following advantages: 1. High integration and significantly reduced size and weight: The system uses a single blue-green laser as the only light source and drives the forward observation, laser communication and downward mapping functions through adjustable beam splitting, which greatly reduces the number of independent light sources and driving circuits. The forward observation and laser communication branches share the transmitting antenna and detector in the optical and detection parts, which further compresses the hardware scale and makes the system easier to integrate into the pressure tank of a small underwater robot, improving the platform's mobility and payload utilization.

[0017] 2. Significantly reduce system power consumption: Light source sharing and on-demand split ratio adjustment allow each functional branch to dynamically allocate optical power according to the task stage, avoiding full power operation when demand is low; in communication mode, there is no need to turn on the forward illumination light, and alignment is completed only by using the beacon light of the communication node, further reducing unnecessary light energy consumption and effectively extending the robot's endurance.

[0018] 3. Flexible function switching and controllable resource competition and interference: The resource scheduling and signal processing modules uniformly control the light source splitting ratio, external modulator working mode, scanning and imaging synchronization, cylindrical mirror entry / exit and beacon light alignment, so as to realize the power-divided operation or flexible switching of the three functions of observation, mapping and communication, avoid optical frequency resource competition and mutual interference, and ensure the stable performance of each mode. Attached Figure Description

[0019] Figure 1 This is a system principle block diagram of the present invention.

[0020] Figure 2 This is a schematic diagram of the optical path and signal flow for realizing the forward-looking observation function of the present invention.

[0021] Figure 3 This is a schematic diagram of the optical path and signal flow for realizing the laser communication function of the present invention.

[0022] Figure 4 This is a schematic diagram of the optical path and signal flow for realizing the downward-looking mapping function of the present invention.

[0023] In the diagram, 1-shared light source module; 2-optical beam splitter module; 3-external modulator; 4-first beam expander optical module; 5-first shaping optical module; 6-reflector; 7-scanning optical module; 8-first imaging optical module; 9-first underwater camera; 10-resource scheduling and signal processing module; 11-second beam expander optical module; 12-second shaping optical module; 13-second imaging optical module; 14-second underwater camera; 15-communication receiving optical module; 16-photodetector. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but these descriptions do not constitute a limitation on the present invention.

[0025] like Figure 1 As shown, this application proposes an integrated underwater observation, mapping, and communication optical system based on shared light source. The system outputs laser light through a shared light source module 1, which is then split into two beams by an optical beam splitter module 2. These beams are supplied to a forward-looking observation and laser communication shared branch and a downward-looking mapping branch, respectively. Simultaneously, a resource scheduling and signal processing module 10 performs mode management, resource scheduling, coordination, closed-loop control, and multi-source information processing for each module, thereby achieving a high degree of integration and efficient coordination of underwater observation, mapping, and communication functions.

[0026] This application provides a single laser source through a shared light source module 1, and the laser is rationally distributed to the forward-looking observation and laser communication shared branch and the downward-looking mapping branch via the optical beam splitting module 2. This achieves full sharing of the light source and reduces the system's size, weight, power consumption, and cost. The forward-looking observation and laser communication shared branch reuses the same optical path in different modes, further improving integration and reducing competition for optical frequency resources. The resource scheduling and signal processing module 10 centrally manages and coordinates the various functional modules, ensuring efficient integration and seamless switching of underwater observation, mapping, and communication functions. This overcomes the problems of limited integration and incomplete task coverage in existing discrete systems, and improves the overall performance of underwater robots in multi-task operations.

[0027] The composition and function of each module in this application are described below: The shared light source module 1 refers to the component that provides a single laser source for the entire integrated optical system, and its output laser serves as the foundation for all optical functions of the system. The shared light source module 1 can employ a single laser with an output wavelength in the low-attenuation underwater band (preferably 450nm–550nm blue-green laser). The laser emitted by this unit can effectively overcome the strong attenuation of light signals in the underwater environment, ensuring minimal energy loss during underwater transmission. This enables the shared forward-looking observation and laser communication branch to achieve longer detection distances, clearer imaging effects, and more stable communication links when performing forward-looking observation and laser communication, as well as the downward-looking mapping branch when performing underwater topographic mapping. Consequently, the overall observation, mapping, and communication performance of the system is significantly improved, thereby enhancing the underwater robot's operational capabilities in complex underwater environments and the reliability of data transmission.

[0028] The optical beam splitter module 2 refers to a component used to split the laser output from the shared light source module 1 into at least two independent beams according to a preset or adjustable ratio, for use by different functional branches. The first beam is sent to the shared light source branch of the forward-looking observation branch and the laser communication branch, and the second beam is sent to the downward-looking mapping branch.

[0029] The optical beam splitting module 2 employs a beam splitter with an adjustable splitting ratio. The splitting ratio of this beam splitter is controlled by the resource scheduling and signal processing module 10, enabling dynamic adjustment of the optical power distribution ratio between the forward-looking observation and laser communication shared branch and the downward-looking mapping branch according to current task requirements. This optimizes energy utilization and reduces unnecessary power consumption and heat load while ensuring the normal operation of all functions. Specifically, the beam splitter can be composed of a liquid crystal phase delay unit and a polarizing beam splitter prism. By adjusting the liquid crystal phase delay, the polarization state of the incident light is changed. Combined with the polarizing beam splitter prism, this allows for continuous and adjustable distribution of laser power among different functional branches, adapting to the system's multi-mode operating requirements.

[0030] The shared branch for forward-looking observation and laser communication refers to a functional unit that utilizes the same laser beam in different operating modes to achieve forward-looking scanning and imaging of the target area, as well as the transmission and reception of laser communication signals and beacon light signals. In other words, it realizes both forward-looking observation and laser communication functions in different operating modes. Forward-looking observation mode refers to the system's operation in visual detection and image acquisition of the water area ahead. Laser communication mode refers to the system's operation in data transmission and beacon light reception via laser. Scanning and imaging refers to the process of illuminating the target area point-by-point or line-by-line with laser light and simultaneously acquiring reflected light to construct images or terrain data.

[0031] The forward-looking observation and laser communication shared branch includes an external modulator 3, a beam shaping and scanning unit, an imaging detection module, and a communication receiving unit.

[0032] The external modulator 3 is positioned on the optical path of the first laser beam. It is a device used to control the beam's intensity, phase, or polarization state, and is driven by the resource scheduling and signal processing module 10. In forward-looking observation mode, its main function is to allow the first laser beam to pass through without any modulation, ensuring the original light intensity and quality of the observed image. In laser communication mode, this module modulates the first laser beam according to the data signal provided by the resource scheduling and signal processing module 10, encoding information into the beam to form a communication carrier carrying the information. The external modulator 3 avoids complex mechanical switching of the optical path by rapidly switching between pass-through and modulation states in both modes, improving the flexibility of mode switching and the efficiency of optical path reconstruction.

[0033] The external modulator 3 can be an acousto-optic modulator, which generates periodic changes in the refractive index in the crystal through sound waves to achieve diffraction or switching control of the beam; or it can be an electro-optic modulator, which uses the electro-optic effect to change the refractive index of the crystal by applying an electric field, thereby modulating the phase, intensity or polarization of the beam.

[0034] The beam shaping and scanning unit is responsible for adjusting the shape, divergence angle, and spatial direction of the laser beam. In forward-looking mode, this unit shapes the unmodulated first laser beam into an illumination beam with a specific shape (e.g., a fan shape) and achieves effective coverage and illumination of the target area through one-dimensional spatial scanning. In laser communication mode, this unit shapes the communication carrier into a narrow and directional beam and precisely points it towards a predetermined communication node to achieve efficient point-to-point communication. By dynamically adjusting the beam shape and direction, the beam shaping and scanning unit achieves wide-range scanning illumination in forward-looking mode and precise directional transmission in laser communication mode, ensuring beam optimization in different functional modes.

[0035] The imaging detection module, consisting of a first imaging optical module 8 and a first underwater camera 9, is used to capture light signals and convert them into images or electrical signals. In forward-looking observation mode, this module receives the scanning beam reflected from the target area and converts it into an image for environmental perception, obstacle avoidance, or target recognition. In laser communication mode, this module receives beacon light emitted from the communication node, providing real-time feedback to the system. The resource scheduling and signal processing module 10 analyzes the position information of the beacon light to assist in the precise alignment of the communication beam, thereby ensuring the reliability of communication. The first imaging optical module 8 has progressive imaging capabilities and can employ an sCMOS rolling shutter sensor.

[0036] The communication receiving unit is used to receive and demodulate laser communication signals from the communication node. This unit is responsible for capturing the laser communication signals from the communication node, converting them into electrical signals, and then demodulating the original data information from the electrical signals, thus completing the receiving end processing of data transmission.

[0037] Under the coordinated control of the resource scheduling and signal processing module 10, the devices sharing the forward-looking observation and laser communication branch share the first laser beam, realizing the deep integration of forward-looking observation and laser communication functions. This avoids resource waste and mutual interference caused by separate systems, and improves the multi-task processing capability and resource utilization efficiency of the underwater robot.

[0038] In the above scheme, the beam shaping and scanning unit includes a first beam expanding optical module 4, a first shaping optical module 5, a reflector 6 and a scanning optical module 7 arranged sequentially along the optical path.

[0039] The first beam-expanding optical module 4 is used to adjust the diameter of the first laser beam or communication carrier to reduce the divergence angle, thereby forming a collimated laser beam or collimated communication carrier. The collimated laser beam and collimated communication carrier have a small divergence angle and minimal change in spot size during propagation, which is beneficial for subsequent optical processing and long-distance transmission. This first beam-expanding optical module 4 can be a Keplerian telescope-type beam expander composed of two positive or negative lenses, where the magnification and beam diameter are changed by adjusting the lens spacing; alternatively, a Galilean telescope-type beam expander can be used, which has a compact structure consisting of a concave lens and a convex lens, also capable of beam expansion and collimation.

[0040] The first shaping optical module 5 is used to shape the collimated laser beam into a fan-shaped illumination beam with a certain divergence angle in forward-looking mode. The fan-shaped beam can provide wide field-of-view illumination, suitable for area scanning in forward-looking mode. This first shaping optical module 5 can employ a cylindrical lens group, using one or more cylindrical lenses to diverge the beam in one dimension while maintaining collimation or a small divergence angle in another dimension, thereby forming a fan-shaped beam. In laser communication mode, this module is removed from the optical path under the control of the resource scheduling and signal processing module.

[0041] Reflector 6 is used to change the propagation direction of the light beam, guiding the fan-shaped illumination beam or collimated communication carrier to the scanning optical module. Its function is to optimize the optical path layout and achieve precise beam guidance. This reflector 6 can be a plane reflector, with reflectivity improved through coating technology to ensure minimal light energy loss; or it can be a prism, utilizing the principle of total internal reflection to achieve beam redirection, while also possessing high reflection efficiency and stability.

[0042] The scanning optical module 7, under the control of the resource scheduling and signal processing module 10, performs deflection motion to enable the fan-shaped illumination beam to perform one-dimensional scanning within a preset two-dimensional field of view, or to point the communication carrier towards the communication node. It is the core actuator for realizing beam spatial pointing and scanning. This scanning optical module 7 can employ a microelectromechanical system (MEMS) scanning mirror, which is small in size and has a fast response speed. It controls the mirror deflection angle via electrical signals to achieve high-precision beam scanning and pointing.

[0043] In the above scheme, the communication receiving unit includes a communication receiving optical module 15 and a photodetector 16, which can provide reliable and efficient laser communication signal reception and conversion capabilities, thereby ensuring the stability of overall communication performance and the real-time nature of data transmission. The communication receiving optical module 15 is used to receive the laser communication signal emitted by the communication node and focus it onto the photodetector 16. The communication receiving optical module 15 can be composed of one or more optical elements. For example, it can employ a receiving optical system composed of lens groups (such as convex lenses or aspherical lenses). By precisely designing the optical parameters, it is ensured that the received diverging beam can be efficiently converged onto the photosensitive surface of the photodetector 16, thereby maximizing the capture of optical signal energy. The photodetector 16 is used to convert the laser communication signal into an electrical signal and output it to the resource scheduling and signal processing module 10. The photodetector 16 can be a PIN photodiode, which has the characteristics of fast response speed and low noise, making it suitable for the conversion of high-speed laser communication signals.

[0044] In forward-looking observation mode, the first laser beam output from the optical beam splitter module 2 first enters the external modulator 3, which is in a direct-through state (unmodulated). The unmodulated laser beam passes sequentially through the first beam expanding optical module 4 (laser beam expander) and the first shaping optical module 5 (cylindrical mirror or diffractive optical element DOE), forming a fan-shaped illumination beam with a certain divergence angle. After being reflected by the reflector 6, the fan-shaped beam is scanned in one-dimensional space by the scanning optical module 7 (such as a rotating polygonal mirror or MEMS galvanometer), so that the illumination area is gradually covered within the robot's forward field of view. The target reflected light is imaged onto the progressive scan array detector (such as a CMOS rolling shutter sensor) by the imaging optical device (including lens group and narrowband filter). The scanning speed and trajectory are kept synchronized, so that the linear spatial reflected light corresponding to each scanning position is received by the detector in a different row sequence.

[0045] The laser communication mode and the forward-looking observation mode share the same first laser beam on the light source side and switch between functions through the same external modulator 3. The external modulator 3 loads the data signal from the resource scheduling and signal processing module 10, converting the first laser beam into a communication carrier. A movable support or rotating mirror mechanism (not shown in the figure) is provided in the optical path after the external modulator 3. Under the control of the resource scheduling and signal processing module 10, the first shaping optical module 5 can be moved out of the optical path, allowing the beam to pass through the first beam expanding optical module 4, the reflector 6, and the scanning optical module 7, forming a directional blue-green laser beam that is sent to the communication node. The beacon light emitted by the communication node is received by a progressive scan array detector (i.e., the first underwater camera 9). The resource scheduling and signal processing module 10 fine-tunes the scanning optical module 7 by analyzing the offset of the beacon spot in the image, achieving high-precision beam alignment. The forward-looking observation branch is not operational at this time. An independent communication receiving channel is set up to capture and demodulate the communication laser signal returned by the other party.

[0046] The downward-looking mapping branch refers to a dedicated functional unit that uses a second laser beam to scan and image the underwater terrain to obtain three-dimensional information about the underwater environment. The downward-looking mapping branch includes a second beam expanding optical module 11, a second shaping optical module 12, and a downward-looking imaging module arranged sequentially along the optical path.

[0047] The second beam-expanding optical module 11 is used to adjust the diameter of the second laser beam to reduce the divergence angle, thereby forming a collimated laser beam. The core function of this module is to expand and collimate the laser beam to improve its directivity and energy density, providing a high-quality incident light source for subsequent beam shaping and scanning. The second beam-expanding optical module 11 can employ a Keplerian telescope-type beam expander composed of two positive lenses. By adjusting the distance between the lenses, the beam expansion magnification and the diameter of the output beam can be precisely controlled, thereby effectively reducing the beam divergence angle.

[0048] The second shaping optical module 12 is designed to convert the collimated laser beam into a light plane with a specific geometry (fan-shaped) and project it vertically downwards to form a clear, bright scan line against the seabed surface in an underwater environment. This facilitates the capture of topographic details and improves the accuracy and coverage of mapping. The second shaping optical module 12 may consist of one or more cylindrical lenses, which focus or diverge the straight laser beam in one dimension while remaining unchanged in another dimension, thereby forming the desired fan-shaped beam.

[0049] The downward imaging module has a similar structure to the imaging detection module mentioned above. It consists of a second imaging optical module 13 and a second underwater camera 14. This module is a key component for acquiring underwater topographic visual data. By capturing the scan line image formed by the fan-shaped light plane on the seabed, it provides raw data for subsequent topographic reconstruction and mapping.

[0050] The refined optical design and component configuration of the downward-looking mapping branch enable the downward-looking mapping function to operate efficiently and accurately within the framework of a shared light source, making full use of light source resources and improving the overall performance of underwater topographic mapping.

[0051] The resource scheduling and signal processing module 10 is the core unit responsible for centralized control, management, and data processing of the entire system. It can be composed of an FPGA or a high-performance MCU and is electrically connected to the shared light source module 1, the optical beam splitter module 2, the forward-looking observation and laser communication shared branch, and the downward-looking mapping branch. Its functions include mode switching according to task requirements, optical power allocation, coordinated control of various modules, and processing of acquired multi-source data.

[0052] The following is a detailed explanation of the functions implemented by the resource scheduling and signal processing module: Mode scheduling control: According to the preset task stage instructions, the optical power allocation ratio of the optical beam splitter module 2 is controlled to avoid resource waste caused by fixed allocation and optimize energy use efficiency; and the working mode of the shared branch of forward observation and laser communication is switched to perform time-sharing or power-sharing work scheduling among the three functional modes of forward observation, laser communication and downward mapping, which improves the flexibility of task execution and the collaborative efficiency of multi-functional integration.

[0053] Optical and signal path control: In coordination with the configurable optical elements and actuators in each functional branch, it controls the entry or exit of the corresponding optical path components (such as the first shaping optical module) and the start / stop and working status of the external modulator 3 during mode switching, so as to construct the physical optical and signal paths required for the current task, ensuring the rapid and accurate reconstruction of the physical optical and signal paths, and enhancing the adaptability and reliability of the system.

[0054] Timing synchronization control: In modes that require scanning and imaging to work together, a synchronization timing signal is generated and sent to ensure precise synchronization between the beam scanning action and the detector exposure / acquisition action. This avoids the disconnect between the beam scanning and detector exposure / acquisition actions caused by timing misalignment, thereby improving the image quality and data accuracy in forward-looking observation and downward-looking mapping modes.

[0055] Closed-loop feedback control: Based on sensor information fed back from the system itself or external nodes, control commands are generated to dynamically adjust the actuators, achieving adaptive optimization of system functions, including precise alignment control of the communication beam based on feedback from the imaging detector. This closed-loop feedback mechanism enables the system to dynamically adjust the beam direction according to real-time environmental changes and target movement, enhancing the stability and reliability of the laser communication link and reducing the risk of communication interruption.

[0056] Data processing and fusion: The system processes, calculates, and fuses raw images or photoelectric signals collected from various branch detectors to output structured information usable for the mission, including stitching together 3D terrain data, demodulating communication data, and generating observation images. This output of structured information enables the integrated underwater observation, mapping, and communication optical system to more effectively support the navigation, communication, and operational tasks of underwater robots.

[0057] The principle behind the above-mentioned integrated optical system for underwater observation, mapping, and communication, which enables forward-looking observation, laser communication, and downward-looking mapping, is as follows: 1. To achieve forward-looking observation function, such as... Figure 2 As shown, the optical components involved include: a shared light source module 1, an optical beam splitter module 2, an external modulator 3, a first beam expander optical module 4, a first shaping optical module 5, a reflector 6, a scanning optical module 7, a first imaging optical module 8, a first underwater camera 9, and a resource scheduling and signal processing module 10. The working process is as follows: 1.1 The laser in the shared light source module 1 is driven by the resource scheduling and signal processing module 10 and outputs a green laser beam with a length of 532nm.

[0058] 1.2 The laser beam is split by the optical beam splitting module 2 and then input to the external modulator 3. In forward-looking observation mode, the external modulator 3 is in standby mode. The optical beam splitting module 2 is controlled by the resource scheduling and signal processing module 10 and can accurately split the laser beam according to a preset ratio.

[0059] 1.3 The unmodulated first laser beam is shaped into a fan-shaped illumination beam with a certain divergence angle after passing through the first beam expanding optical module 4 and the first shaping optical module 5.

[0060] 1.4 A reflector 6 is arranged at a 45° angle to the optical path after the first shaping optical module 5 to change the propagation direction of the laser beam.

[0061] 1.5 The fan-shaped beam reflected by the fixed reflector 6 is incident on the scanning optical module 7 driven by the resource scheduling and signal processing module 10, thereby realizing line-by-line scanning imaging within a preset detection range.

[0062] 1.6 The light beam reflected by the target passes through the first imaging optical module 8 and is then imaged by the first underwater camera 9. Under the control of the resource scheduling and signal processing module 10, the first underwater camera 9 can ensure that the laser beam reflected by the target precisely illuminates the instantaneous exposure area of ​​the image sensor.

[0063] 1.7 The images acquired by the first underwater camera 9 are transmitted to the resource scheduling and signal processing module 10. The module performs the corresponding image post-processing and finally realizes the forward-looking observation function of the system.

[0064] 2. To achieve laser communication functionality, such as... Figure 3 As shown, the optical components involved include: a shared light source module 1, an optical beam splitter module 2, an external modulator 3, a first beam expander optical module 4, a reflector 6, a scanning optical module 7, a first imaging optical module 8, a first underwater camera 9, a resource scheduling and signal processing module 10, a communication receiving optical module 15, and a photodetector 16. The working process is as follows: 2.1 The laser in the shared light source module 1 is driven by the resource scheduling and signal processing module 10 and outputs a green laser beam with a wavelength of 532nm.

[0065] 2.2 After being split by the optical beam splitter module 2, the laser beam is input to the external modulator 3; the external modulator 3 loads the target signal to be transmitted and modulates the laser beam into a communication carrier carrying information.

[0066] 2.3 Under the drive of the resource scheduling and signal processing module 10, the first shaping optical module 5 is removed from the optical path, and at this time the forward-looking observation branch stops working.

[0067] 2.4 After passing through the first beam-expanding optical module 4, the reflector 6 at a 45° angle to the optical path, and the scanning optical module 7, the communication carrier is precisely aligned with the communication node, thereby completing the information transmission function. The precise alignment process is as follows: the beacon light emitted by the communication node is received in real time by the first underwater camera 9. The resource scheduling and signal processing module 10 performs quantitative analysis and calculation on the offset of the beacon light spot within the imaging plane of the first underwater camera 9, and outputs control commands accordingly to fine-tune the attitude and angle of the scanning optical module 7, thereby achieving high-precision alignment between the laser communication carrier and the communication node.

[0068] 2.5 The communication receiving channel is set up independently. The carrier wave sent by the communication node enters the photodetector 16 through the communication receiving optical module 15. The photodetector 16 transmits the detected light signal to the resource scheduling and signal processing module 10 for demodulation processing, thereby realizing the information receiving process.

[0069] 3. Implement downward surveying functions, such as... Figure 4 As shown, the optical components involved include: a shared light source module 1, an optical beam splitter module 2, a resource scheduling and signal processing module 10, a second beam expander optical module 11, a second shaping optical module 12, a second imaging optical module 13, and a second underwater camera 14. The working process is as follows: 3.1 The laser in the shared light source module 1 is driven by the resource scheduling and signal processing module 10 and outputs a green laser beam with a wavelength of 532nm.

[0070] 3.2 After being split by the optical beam splitting module 2, the laser beam passes sequentially through the second beam expanding optical module 11 and the second shaping optical module 12, and is shaped into a fan-shaped beam, which is then projected vertically downwards onto the seabed detection area. The fan-shaped beam forms a light plane in the seawater, and after intersecting with the seabed topography, it produces a bright scanning line. When the seabed topography is undulating, the scanning line will show corresponding concavity, convexity, or breakage deformation in the image captured by the camera. Using the principle of triangulation, the distance information in the line space can be inverted from the deformation of the scanning line, thereby obtaining the three-dimensional coordinates of the local topography. As the robot moves at a constant speed along the heading or perpendicular to the light plane, the fan-shaped light plane performs one-dimensional sweeping of the terrain below. By sequentially stitching together the three-dimensional data of each scanning line, wide-area three-dimensional terrain information can be obtained.

[0071] 3.3 After the reflected laser light from the scan line is imaged by the second imaging optical module 13 and the second underwater camera 14, the acquired image data is transmitted to the resource scheduling and signal processing module 10. As the underwater robot carrying this system travels at a constant speed along its course or perpendicular to the light plane, the fan-shaped light plane performs one-dimensional push-broom detection of the seabed topography below. By sequentially stitching together the three-dimensional data of the scan line acquired frame by frame, a large-scale three-dimensional topographic information of the seabed area can be generated. After subsequent data processing by the module, accurate mapping of the three-dimensional seabed topography is finally achieved.

[0072] 4. The tasks to be performed by the resource scheduling and signal processing module 10 include: 4.1 Timing Generation and Resource Allocation: For the three task phases of cruise observation, terrain mapping, and data transmission, time-sharing or power-sharing work timing instructions are generated and issued to allocate the light source energy occupancy rights of each functional branch, so that each branch can obtain light source power on demand and avoid competition for optical frequency resources and mutual interference between branches.

[0073] 4.2 Timing Synchronization and Mode Control: Synchronously regulate the scanning action of the scanning optical module 7 and the exposure timing of the detector rolling shutter; complete the rapid switching of communication modes and the high-precision alignment of the beacon light, and ensure the stable operation of the system during multi-task switching.

[0074] 4.3 Image and Signal Processing: Responsible for back-end image and signal processing tasks such as scanning image stitching and fusion, laser communication carrier demodulation and decoding, and outputting processing results that meet the task requirements.

[0075] This application proposes an integrated underwater observation, mapping, and communication optical system based on shared light source. Using a single blue-green laser as the sole shared light source, and employing an adjustable beam splitting structure, it achieves three main functions: forward-looking observation, laser communication, and downward-looking mapping. This effectively reduces the number of light sources and associated driving circuits, significantly compressing the hardware integration scale and improving system integration, while simultaneously reducing overall power consumption. A dynamic adjustable power allocation strategy avoids competition for optical frequency resources and mutual interference between branches, ensuring performance stability in all operating modes. This system effectively solves the technical pain points of traditional underwater optical systems, which require separate light sources and optical links for observation, mapping, and communication functions, resulting in bulky hardware, high integration difficulty, redundant power consumption, mutual interference between multiple optical frequency resources, and poor mode switching compatibility. It is suitable for applications requiring miniaturized platforms.

[0076] It is understood that those skilled in the art will clearly recognize that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application.

[0077] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application. Content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims

1. An integrated underwater observation, mapping, and communication optical system based on shared light source, characterized in that, include: A shared light source module is used to output laser light; An optical beam splitter module is used to split the laser into two laser beams; The forward-looking observation and laser communication share a branch, which is used to scan and image the target area based on the first laser beam output by the optical beam splitter module in the forward-looking observation mode, and to transmit laser communication signals and receive beacon light signals and laser communication signals in the laser communication mode. The downward-looking mapping branch is used to scan and image underwater terrain based on the second laser beam output by the optical beam splitter module; The resource scheduling and signal processing module is electrically connected to the shared light source module, the optical beam splitting module, the forward-looking observation and laser communication shared branch, and the downward-looking mapping branch, respectively. It is used to perform mode management and resource scheduling according to task requirements, coordinate and close-loop control of each module, and process multi-source information.

2. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 1, characterized in that: The shared light source module includes a laser for outputting laser light with a wavelength in the low-attenuation band underwater.

3. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 1, characterized in that: The optical beam splitting module includes a beam splitter with an adjustable splitting ratio. The splitting ratio of the beam splitter is controlled by the resource scheduling and signal processing module, which can dynamically adjust the optical power distribution ratio of the forward observation and laser communication shared branch and the downward mapping branch according to the current task requirements.

4. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 1, characterized in that, The shared branch for forward-looking observation and laser communication includes: An external modulator is disposed on the optical path of the first laser beam. It is used to be in a direct state in forward-looking observation mode and to load the data signal of the resource scheduling and signal processing module in laser communication mode to modulate the first laser beam to form a communication carrier carrying information. The beam shaping and scanning unit is used to shape the unmodulated first laser beam into a fan-shaped illumination beam and perform one-dimensional spatial scanning in forward-looking observation mode, and to shape the communication carrier into a directional beam and point it toward the communication node in laser communication mode. The imaging detection module is used to receive and image the scanning beam reflected by the target in forward-looking observation mode, and to receive the beacon light signal emitted by the communication node in laser communication mode to assist in beam alignment. The communication receiving unit is used to receive and demodulate laser communication signals from the communication node.

5. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 4, characterized in that: The beam shaping and scanning unit includes a first beam expanding optical module, a first shaping optical module, a reflector, and a scanning optical module arranged sequentially along the optical path. In forward-looking observation mode, the first beam expanding optical module is used to adjust the diameter of the first laser beam to reduce the divergence angle and form a collimated laser beam. The first shaping optical module shapes the collimated laser beam into a fan-shaped illumination beam with a certain divergence angle. The fan-shaped illumination beam is reflected by a mirror and guided to the scanning optical module. Under the control of the resource scheduling and signal processing module, the scanning optical module performs deflection motion so that the fan-shaped illumination beam performs one-dimensional scanning within a preset two-dimensional field of view, thereby illuminating the forward-looking area line by line. In laser communication mode, the resource scheduling and signal processing module controls the first shaping optical module to move out of the optical path. The first beam expanding optical module is used to adjust the diameter of the communication carrier to reduce the divergence angle and form a collimated communication carrier. The collimated communication carrier is guided to the scanning optical module after being reflected by the mirror. The scanning optical module performs deflection movement under the control of the resource scheduling and signal processing module so that the collimated communication carrier points to the communication node.

6. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 4, characterized in that: The communication receiving unit includes a communication receiving optical module and a photodetector. The communication receiving optical module is used to receive laser communication signals emitted by the communication node and focus them onto the photodetector. The photodetector is used to convert the laser communication signals into electrical signals and output them to the resource scheduling and signal processing module.

7. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 1, characterized in that: The downward-looking mapping branch includes a second beam-expanding optical module, a second shaping optical module, and a downward-looking imaging module arranged sequentially along the optical path; The second beam expander optical module is used to adjust the diameter of the second laser beam to reduce the divergence angle and form a collimated laser beam; The second shaping optical module is used to shape the collimated laser beam into a vertically downward fan-shaped light plane, which intersects with the seabed to form a scanning line; The downward-facing imaging module is used to capture images containing the scan lines.

8. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 1, characterized in that, The aforementioned mode management and resource scheduling based on task requirements includes: The optical power distribution ratio of the optical beam splitter module is controlled according to external instructions or preset strategies; Switch the working mode of the shared branch of forward observation and laser communication to perform time-sharing or power-sharing work scheduling among the three functional modes of forward observation, laser communication and downward mapping. During mode switching, the corresponding optical path components are switched in or out, and the external modulator is started, stopped, and its working status is controlled to construct the physical optical path and signal path required for the current task.

9. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 1, characterized in that, The coordinated and closed-loop control of each module includes: In modes where scanning and imaging need to work together, a synchronization timing signal is generated and sent to coordinate the working timing of the light source, scanning, imaging, and modulation modules. Control commands are generated based on feedback information to dynamically adjust the actuators.

10. The underwater observation, mapping, and communication integrated optical system based on light source sharing according to claim 1, characterized in that, The processing of multi-source information includes: The raw images or photoelectric signals collected by each module are processed to output structured information that can be used by the task. The processing includes generating observation images, demodulating communication data, and stitching together three-dimensional terrain data.

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