Navigation positioning terminal anti-salt corrosion detection device and positioning terminal

Abstract

The application relates to the field of Beidou navigation and positioning technology, in particular to a navigation and positioning terminal anti-salt-mist corrosion detection device and a positioning terminal. The device comprises an anti-salt-mist corrosion shell and a positioning terminal arranged in the interior. The anti-salt-mist corrosion shell adopts an aluminum alloy profile main body, the surface of which is subjected to hard anodic oxidation treatment to form an oxidation layer with a thickness of greater than or equal to 20 micrometers, and a ring-shaped silica gel sealing ring is arranged at the joint of the shell to meet the IP68 protection level. The application extracts the latest 300-second track and clock correction based on a sliding window prediction module, adopts a least square fitting track model and a quadratic polynomial clock difference model with an additional period term, maintains the centimeter-level positioning accuracy for greater than or equal to 60 minutes when the star-based differential signal is interrupted, and the re-convergence time is less than or equal to 5 minutes, so that the defects that the error of the traditional equipment diverges to the meter level within 10 minutes are overcome, and the continuity requirement of the dynamic positioning system is met.

Description

Technical Field

[0001] This invention relates to the field of BeiDou navigation and positioning technology, and in particular to a salt spray corrosion detection device and positioning terminal for navigation and positioning terminals. Background Technology

[0002] In many marine-related fields such as modern marine engineering construction, ocean shipping, and near-shore fishing operations, navigation and positioning terminals are core equipment to ensure the accurate conduct of various maritime activities. They not only provide real-time key information such as position and course for the safe navigation of ships, but also provide high-precision positioning support for operations such as marine resource exploration and subsea engineering construction. However, the marine environment is extremely unique, with high concentrations of salt spray, drastic temperature and humidity changes, and complex electromagnetic interference, which place extremely high demands on the structural stability and performance reliability of navigation and positioning terminals.

[0003] Regarding resistance to salt spray corrosion, some existing terminal shells are made of ordinary materials with thin protective coatings, making it difficult to withstand long-term salt spray erosion. The sealing performance at the shell seams is poor, which can easily lead to the infiltration of moisture and salt, affecting the normal operation of internal components and greatly shortening the service life of the equipment. In terms of signal, when the satellite-based differential signal is lost (such as due to obstruction by geostationary satellites), the existing equipment lacks an effective short-term accuracy maintenance mechanism. The positioning error diverges to the meter level within 10 minutes, which cannot meet the continuity requirements of the dynamic positioning system (DPS). At the same time, when external sensors (IMU / DVL / AIS) are connected, the drive protocol needs to be manually configured, and the priority switching logic in case of equipment failure has not been established, resulting in a positioning source switching delay of more than 30 seconds, increasing the risk to navigation safety.

[0004] Therefore, in response to the problems mentioned above, this invention proposes a salt spray corrosion detection device and a positioning terminal for navigation and positioning terminals. Summary of the Invention

[0005] To overcome the problems of poor corrosion resistance and signal interruption accuracy collapse of existing navigation and positioning terminals, this invention proposes a salt spray corrosion detection device and positioning terminal for navigation and positioning terminals. Through a layered shielded shell structure, a sliding window prediction algorithm for orbit and clock difference, a plug-and-play multi-source interface management system, and a temperature difference adaptive heat dissipation system, it achieves continuous and stable centimeter-level positioning output in complex marine environments.

[0006] The technical solution of the present invention is as follows: a navigation and positioning terminal anti-salt spray corrosion detection device, comprising an anti-salt spray corrosion shell and a positioning terminal installed inside, wherein the anti-salt spray corrosion shell is made of aluminum alloy profile body, the surface is hard anodized to form an oxide layer of ≥20μm, and an annular silicone sealing ring is provided at the seam of the shell to meet the IP68 protection level.

[0007] As a preferred option, the salt spray corrosion resistant shell includes a layered shielding structure and shock-absorbing components. The layered shielding structure consists of, from the outside to the inside, a 0.5mm thick aluminum oxide layer, a 200-mesh electromagnetic shielding copper mesh, and a moisture-proof and insulating coating made of polytetrafluoroethylene. The four corners of the shell's main board are fixed with silicone shock-absorbing columns, and the compression deformation rate of the shock-absorbing columns is ≤5%.

[0008] As a preferred embodiment, a navigation and positioning terminal includes:

[0009] The multi-source interface module integrates a BeiDou multi-band signal receiving interface, an IMU inertial measurement unit interface, a DVL Doppler velocimeter interface, and an AIS automatic identification system interface. Each interface is connected via a waterproof aviation plug.

[0010] The core processing unit is based on an FPGA programmable logic architecture and includes a built-in BeiDou satellite-based augmentation signal analysis module, a multi-source data fusion algorithm module, and a sliding window prediction module.

[0011] The thermal management module has a graphene thermal conductive layer attached to the inner wall of the outer shell and heat dissipation fins installed at the bottom, with an operating temperature range of -40℃ to +70℃.

[0012] The low-power management unit is equipped with a multi-level voltage regulation circuit and supports switching power consumption modes. The power consumption in normal mode is ≤15W and the power consumption in standby mode is ≤2W.

[0013] Preferably, the BeiDou multi-band signal receiving interface of the multi-source interface module simultaneously supports BeiDou-2 B1I / B2I / B3I and BeiDou-3 B1C / B2a / B2b signals, and has a built-in L-band satellite differential signal decoder, compatible with RTCM 3.2 protocol and custom narrowband broadcasting protocol.

[0014] Preferably, the sliding window prediction module of the core processing unit performs short-term orbit and clock error prediction when the satellite-based differential signal is interrupted: extracts the orbit correction and clock error correction of the most recent 300 seconds, and generates an orbit prediction model using the least squares fitting method and generates a clock error prediction model using a quadratic polynomial fitting method with an additional periodic term, maintaining centimeter-level positioning accuracy for ≥60 minutes and reconvergence time ≤5 minutes.

[0015] Preferably, the thermal management module's heat dissipation fins include: a fin substrate made of copper-aluminum alloy, a surface with a micro-groove structure, a groove depth of 0.2 mm, a spacing of 1 mm, and a built-in temperature sensor that links to the fan, activating forced air cooling when the core temperature is >55℃.

[0016] Preferably, the low-power management unit dynamically detects the ship's motion state to switch the processing frequency and monitors the connection status of external devices in real time to intelligently shut down the power supply circuit of unused interfaces, thereby achieving multi-level power consumption control. The ship's motion state includes three working conditions: stationary, sailing, and operation. The processing frequency is reduced to 1Hz in stationary mode and increased to 10Hz in operation mode.

[0017] Preferably, the plug-and-play configuration module automatically identifies the type of external device, loads the corresponding driver protocol, and dynamically optimizes the positioning algorithm according to the device combination. At the same time, it constructs a priority list including Beidou, IMU, DVL, and AIS to achieve seamless switching between primary and backup positioning sources.

[0018] Preferably, the plug-and-play configuration module can construct a priority table for the devices, where BeiDou > IMU > DVL > AIS. When the primary positioning source fails, the backup source is switched in sequence. A multi-source fusion weight matrix is ​​generated by calculating the signal-to-noise ratio and positioning accuracy of each device in real time. The weight coefficient of BeiDou signal is set to 0.8 when SNR≥40dB, and the weight of IMU data is increased to 0.6 in the high dynamic environment of ships. The weight allocation is updated every 5 seconds.

[0019] Preferably, the positioning terminal can analyze the BeiDou positioning data in real time through a software platform and overlay electronic nautical charts to display the ship's motion trajectory, output a quality control report including gross error marking, cycle slip detection and multipath effect analysis, and provide a centimeter-level position feedback interface that meets the requirements of the dynamic positioning system for marine engineering vessels.

[0020] The beneficial effects of this invention are:

[0021] 1. This invention extracts the orbit and clock error corrections for the most recent 300 seconds based on the sliding window prediction module, and adopts the least squares fitting orbit model and the quadratic polynomial clock error model with an additional periodic term. It maintains centimeter-level positioning accuracy for ≥60 minutes and reconvergence time for ≤5 minutes when the satellite-based differential signal is interrupted. It overcomes the defect of traditional equipment where the error diverges to the meter level within 10 minutes and meets the continuity requirements of dynamic positioning system (DPS).

[0022] 2. This invention utilizes the hard anodizing treatment of the aluminum alloy profile body surface and the design of annular silicone sealing rings at the joints. The terminal salt spray corrosion resistance meets the 48-hour 5% NaCl spray test standard, thereby effectively preventing sealing failure caused by electrochemical corrosion. The silicone shock-absorbing pillars at the four corners of the main board, combined with the layered shielding structure (alumina layer + electromagnetic shielding copper mesh + moisture-proof insulating coating), achieve 50G impact resistance, solving the problem of component desoldering caused by ship vibration and ensuring that the IP68 protection level is stably maintained in harsh marine environments.

[0023] 3. The plug-and-play configuration module of the present invention automatically identifies external devices such as IMU, DVL, and AIS and loads the driver protocol. Through priority list and dynamic weight matrix, it completes the switchover of backup source within 30 seconds when the primary positioning source fails. Compared with manual configuration, it significantly reduces the delay and thus significantly improves navigation safety. Attached Figure Description

[0024] Figure 1 The diagram shown illustrates the workflow of this invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The present invention provides an embodiment: a navigation and positioning terminal anti-salt spray corrosion detection device, comprising an anti-salt spray corrosion shell and a positioning terminal disposed inside.

[0027] The salt spray corrosion resistant shell of this invention uses an aluminum alloy profile as the main body, which is hard anodized to form an oxide layer of ≥20μm. The shell seams are provided with annular silicone sealing rings to meet the IP68 protection level. The salt spray corrosion resistant shell includes a layered shielding structure and shock-absorbing components. The layered shielding structure consists of, from the outside to the inside, a 0.5mm thick aluminum oxide layer, a 200 mesh electromagnetic shielding copper mesh, and a moisture-proof and insulating coating made of polytetrafluoroethylene. The four corners of the shell main body are fixed with silicone shock-absorbing columns, and the compression deformation rate of the shock-absorbing columns is ≤5%.

[0028] To ensure the equipment's environmental adaptability and stable operation in marine environments with large temperature differences, high humidity, and strong corrosiveness, while meeting IP65 waterproof, dustproof, shockproof, and drop-resistant requirements, the receiver adopts a metal profile design and incorporates waterproof sealing rings and shockproof silicone parts. To further enhance environmental adaptability, the receiver's operating temperature range (-55℃ to +70℃) and storage temperature range (-55℃ to +70℃) were considered from component selection to overall system testing. For battery selection, lithium-ion batteries with an operating temperature range of -20℃ to +60℃ were strictly chosen to ensure the receiver terminal is fully functional. It meets the operating temperature requirements of -20℃ to +45℃ and the storage temperature requirements of -20℃ to +60℃. The outer shell is designed with an aluminum oxide layer to ensure that its corrosion resistance meets the requirements. The whole unit adopts a custom silicone sealing ring design, and the internal components are fastened with screws. The outer sheath of the internal RF cable is connected to the PCB board with a high connection strength MMCX RF connector. Lightweight surface mount components are selected as much as possible to reduce the impact of vibration and shock on the components, thereby ensuring that the receiver meets the technical requirements of IP65 waterproof and dustproof, corrosion resistance, shock resistance and drop resistance.

[0029] Furthermore, the alumina layer can block salt spray penetration, the electromagnetic shielding copper mesh can suppress high-frequency interference from ship radar / communication equipment, and the polytetrafluoroethylene coating can prevent condensation from entering the circuit board.

[0030] Silicone shock absorbers have a deformation rate of ≤5% under 50G impacts such as ship running aground or being hit by storm waves, thus ensuring that the motherboard is not damaged by displacement. Compared with traditional rigid fixing methods, their vibration resistance is greatly improved, thereby eliminating the risk of "component desoldering caused by ship vibration".

[0031] Furthermore, a navigation and positioning terminal includes:

[0032] The multi-source interface module integrates a BeiDou multi-band signal receiving interface, an IMU inertial measurement unit interface, a DVL Doppler velocimeter interface, and an AIS automatic identification system interface. Each interface is connected via a waterproof aviation plug.

[0033] The core processing unit is based on an FPGA programmable logic architecture and includes a built-in BeiDou satellite-based augmentation signal analysis module, a multi-source data fusion algorithm module, and a sliding window prediction module.

[0034] The thermal management module has a graphene thermal conductive layer attached to the inner wall of the outer shell and a thermal differential heat dissipation fin installed at the bottom. The operating temperature range covers -40℃ to +70℃. Uniform heat dissipation is achieved through the graphene thermal conductive layer attached to the inner wall of the outer shell and the copper-aluminum alloy thermal differential heat dissipation fin at the bottom.

[0035] The low-power management unit is equipped with a multi-level voltage regulation circuit and supports switching power consumption modes, including normal mode and standby mode. In normal mode, the power consumption is ≤15W, and in standby mode, it is ≤2W.

[0036] Furthermore, the multi-source interface module of this invention is compatible with multiple frequency points simultaneously, thereby eliminating the 10-second positioning interruption caused by the frequency band switching required by traditional terminals and solving the problem of discontinuous signal reception in traditional settings. This invention configures a BeiDou multi-band signal receiving interface in the multi-source interface module, and the physical layer hardware synchronously receives BeiDou-2 B1I / B2I / B3I and BeiDou-3 B1C / B2a / B2b signals. The built-in L-band satellite differential signal decoder integrates a dual-protocol processing kernel, which real-time parses RTCM 3.2 format messages and custom narrowband broadcast protocols (frame structure includes 32-bit synchronization frame header, 3-bit L-band ID, 2-bit reserved bits, 11-bit frame length, ≤5944-bit message, and 24-bit CRC check bits), and performs SM4 block cipher algorithm (128-bit key) encryption and decryption operations on the custom protocol message content.

[0037] Among them, the RTCM 3.2 protocol supports Internet broadcasting scenarios, and the custom protocol is adapted to the weak signal environment of L-band satellites (frame length ≤ 6000 bits to ensure transmission is completed within 5 seconds). When the near-shore operator's network fails, it automatically switches to the satellite link, increasing the communication availability from 90% to 99.9%. At the same time, SM4 encryption blocks the risk of differential data tampering, and the positioning offset rate is reduced by 98% compared with the unencrypted protocol.

[0038] Furthermore, the sliding window prediction module of the core processing unit monitors the status of the satellite-based differential signal in real time. When an interruption is detected, it immediately extracts the orbital correction and clock error correction received in the last 300 seconds. The orbital prediction uses a block-based recursive least squares configuration method to establish a dynamic constraint model, and the clock error prediction uses a quadratic polynomial fitting method with an additional periodic term. The orbital offset and clock error correction values ​​for the next 60 minutes are generated through real-time calculation and injected into the positioning calculation process. During the signal interruption, the horizontal positioning error is maintained at ≤5cm, and it converges to centimeter-level accuracy within 5 minutes after the signal is restored.

[0039] The 300-second time window covers 60 epochal data points, and the least squares orbital model can suppress the divergence of the predicted position. The traditional linear model has an error of 1.2m after 60 minutes, while this invention can optimize it to 5.8cm, thus solving the problem of the accuracy collapsing to the meter level after 10 minutes of signal interruption.

[0040] Furthermore, the thermal management module is equipped with copper-aluminum alloy thermal fins with a surface textured with a depth of 0.2mm and a spacing of 1mm for the micro-groove array. The bottom of the fins integrates a temperature sensor with an accuracy of ±0.5℃. The fan is linked by a PID control circuit. When the core processing unit temperature is >55℃, the fan is triggered for forced air cooling. At the same time, the graphene thermal conductive layer (thermal conductivity 5300W / m·K) attached to the inner wall of the shell evenly conducts the heat from the motherboard to the fin substrate, enabling the terminal to work continuously in a temperature range of -40℃ to +70℃.

[0041] Among them, the micro-groove structure can increase the heat dissipation surface area, the graphene thermal conductive layer can eliminate local hot spots on the motherboard (temperature difference ≤5℃), and the temperature sensor linked to the fan can maintain the core processing unit temperature below 55℃; at the same time, the copper-aluminum alloy substrate has better corrosion resistance than ordinary aluminum alloy, and the micro-groove avoids the accumulation of condensate; the fan of this invention only starts at high temperature, which can significantly reduce power consumption.

[0042] The plug-and-play configuration module automatically identifies the type of external device, loads the corresponding driver protocol, and dynamically optimizes the positioning algorithm based on the device combination. At the same time, it constructs a priority list including BeiDou, IMU, DVL, and AIS to achieve seamless switching between primary and backup positioning sources.

[0043] The plug-and-play configuration module can build a priority table for the devices, where BeiDou > IMU > DVL > AIS. When the primary positioning source fails, the backup source is switched in sequence. A multi-source fusion weight matrix is ​​generated by calculating the signal-to-noise ratio and positioning accuracy of each device in real time. The weight coefficient of BeiDou signal is set to 0.8 when SNR≥40dB, and the weight of IMU data is increased to 0.6 in the high dynamic environment of ships. The weight allocation is updated every 5 seconds.

[0044] Furthermore, after the plug-and-play configuration module detects that an external device (IMU / DVL / AIS) is connected to the waterproof aviation plug at the physical layer, it automatically executes a protocol handshake signal. For example, the IMU sends the 0xAA55 identifier code and loads the pre-stored driver protocol library (IMU protocol is NMEA-0183, DVL protocol is PD5 format). According to the device combination dynamic activation optimization algorithm, when IMU and DVL are connected at the same time, it switches to the fused dead reckoning mode (weight allocation: DVL velocity data 70%, IMU angular rate 30%), and builds a priority list of BeiDou > IMU > DVL > AIS. When the BeiDou signal is lost, it seamlessly switches to IMU-led dead reckoning within 30 seconds to avoid positioning gaps caused by manual configuration.

[0045] The positioning terminal can analyze BeiDou positioning data in real time through a software platform and overlay electronic nautical charts to display the ship's motion trajectory. It outputs a quality control report that includes gross error marking, cycle slip detection, and multipath effect analysis. At the same time, it provides a centimeter-level position feedback interface that meets the requirements of a dynamic positioning system for marine engineering vessels.

[0046] Furthermore, the invention functions normally after continuous spraying in a 48-hour 5% NaCl salt spray test chamber. When dropped freely from a height of 1.5m onto the steel plate surface, the silicone shock-absorbing columns absorb the impact energy, resulting in a motherboard displacement of ≤0.1mm. The outer shell shows no cracks or deformation. Electromagnetic compatibility meets marine equipment standards. The PCB stack-up design suppresses radiated interference in the 30MHz-1GHz frequency band to <30dBμV / m.

[0047] Please see Figure 1 Furthermore, the workflow of this invention will be described in detail below:

[0048] When an IMU, DVL, or AIS device is connected to the terminal via a waterproof aviation plug, the plug-and-play configuration module automatically sends a handshake signal, identifies the device type, loads the pre-stored driver protocol (NMEA-0183 / PD5 format), activates the device priority list (BeiDou > IMU > DVL > AIS), and initializes the weight matrix with values, where BeiDou has a default weight of 0.8, IMU 0.3, and DVL 0.5.

[0049] The BeiDou multi-band receiving interface synchronously captures BeiDou-2 B1I / B2I / B3I and BeiDou-3 B1C / B2a / B2b signals. The L-band decoder processes RTCM 3.2 Internet broadcast data and custom satellite differential protocol (32-bit frame header + SM4 encrypted message) in parallel. CRC24 checksum corrects transmission errors and outputs centimeter-level raw positioning coordinates.

[0050] If the satellite-based differential signal is lost, the orbit / clock error correction data of the most recent 300 seconds is immediately extracted. An orbit prediction model is generated by block recursive least squares, and a clock error model is generated by adding a periodic term quadratic polynomial. The positioning error is maintained at ≤5cm for 60 minutes. At the same time, the priority list switching preparation is activated, such as the BeiDou weight is reduced to zero and the IMU weight is increased to 0.9.

[0051] The signal-to-noise ratio (SNR) and accuracy indicators of each device are collected every 5 seconds. When the BeiDou SNR is ≥40dB, the weight remains at 0.8. In the high dynamic environment of ships (angular velocity >5° / s), the IMU weight is increased to 0.6. If the DVL velocity jump is >10%, the weight is reduced to zero. The Kalman filter engine then fuses the weighted data to output the fused positioning result.

[0052] The temperature sensor monitors the status of the core chip in real time. When the core chip temperature is >55℃, the micro-groove heat sink is activated for forced air cooling (wind speed 3m / s). When the ship is stationary, it switches to 1Hz standby mode (power consumption ≤2W). When in operation, it resumes 10Hz positioning.

[0053] The software platform analyzes BeiDou positioning data in real time and overlays it onto electronic nautical charts to display the ship's trajectory. This includes gross errors from the Melbourne-Wubbena combined markers, cycle slip detection from the Geometry-Free combined markers, alarms when the multipath MP value is greater than 0.4, simultaneous overlay of electronic nautical charts to display the 10Hz ship trajectory, and outputting centimeter-level positioning to the dynamic positioning system (DPS) via the RS485 interface.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A salt spray corrosion detection device for navigation and positioning terminals, characterized in that, The device includes a salt spray corrosion resistant shell, which is made of aluminum alloy profile with a hard anodized surface forming an oxide layer of ≥20μm. Annular silicone sealing rings are installed at the shell seams to meet IP68 protection standards. The salt spray corrosion resistant shell includes a layered shielding structure and shock-absorbing components. The layered shielding structure consists of, from the outside to the inside, a 0.5mm thick aluminum oxide layer, a 200-mesh electromagnetic shielding copper mesh, and a moisture-proof insulating coating made of polytetrafluoroethylene. The four corners of the shell's main board are fixed with silicone shock-absorbing columns, with a compression deformation rate of ≤5%.

2. A navigation and positioning terminal, characterized in that, The salt spray corrosion detection device according to claim 1 includes: a multi-source interface module, integrating a Beidou multi-band signal receiving interface, an IMU inertial measurement unit interface, a DVL Doppler velocimeter interface, and an AIS ship automatic identification system interface, with each interface connected via a waterproof aviation plug; and a core processing unit, based on an FPGA programmable logic architecture, which incorporates a Beidou satellite-based augmentation signal analysis module, a multi-source data fusion algorithm module, and a sliding window prediction module. The thermal management module has a graphene thermal conductive layer attached to the inner wall of the shell and heat dissipation fins installed at the bottom, with an operating temperature range of -40℃ to +70℃; the low power management unit is equipped with a multi-level voltage regulation circuit and supports switching power consumption modes, including normal mode and standby mode. In normal mode, the power consumption is ≤15W, and in standby mode, it is ≤2W.

3. A navigation and positioning terminal according to claim 2, characterized in that, The multi-source interface module's BeiDou multi-band signal receiving interface simultaneously supports BeiDou-2 B1I / B2I / B3I and BeiDou-3 B1C / B2a / B2b signals, and has a built-in L-band satellite differential signal decoder, compatible with RTCM 3.2 protocol and custom narrowband broadcasting protocol.

4. A navigation and positioning terminal according to claim 2, characterized in that, The sliding window prediction module of the core processing unit performs short-term orbit and clock error prediction when the satellite-based differential signal is interrupted: it extracts the orbit correction and clock error correction of the most recent 300 seconds, and uses the least squares fitting method to generate an orbit prediction model and uses the quadratic polynomial fitting method with additional periodic terms to generate a clock error prediction model, maintaining centimeter-level positioning accuracy for ≥60 minutes and reconvergence time ≤5 minutes.

5. A navigation and positioning terminal according to claim 2, characterized in that: The thermal management module's temperature difference heat dissipation fins include: a fin substrate made of copper-aluminum alloy, a surface with a micro-groove structure, a groove depth of 0.2mm, and a spacing of 1mm; it also has a built-in temperature sensor that links to the fan, and when the core temperature is >55℃, forced air cooling is activated.

6. A navigation and positioning terminal according to claim 2, characterized in that: The low-power management unit dynamically detects the ship's motion state to switch the processing frequency and monitors the connection status of external devices in real time to intelligently shut down the power supply circuit of unused interfaces, thereby achieving multi-level power consumption control. The ship's motion state includes three working conditions: stationary, sailing, and operation. The processing frequency is reduced to 1Hz in stationary mode and increased to 10Hz in operation mode.

7. A navigation and positioning terminal according to claim 2, characterized in that: The present invention also includes a plug-and-play configuration module, which automatically identifies the type of external device, loads the corresponding driver protocol, dynamically optimizes the positioning algorithm according to the device combination, and builds a priority list including Beidou, IMU, DVL and AIS to achieve seamless switching between primary and backup positioning sources.

8. A navigation and positioning terminal according to claim 7, characterized in that: The plug-and-play configuration module can build a priority table for the devices, where BeiDou > IMU > DVL > AIS. When the primary positioning source fails, the backup source is switched in sequence. A multi-source fusion weight matrix is ​​generated by calculating the signal-to-noise ratio and positioning accuracy of each device in real time. The weight coefficient of BeiDou signal is set to 0.8 when SNR≥40dB, and the weight of IMU data is increased to 0.6 in the high dynamic environment of ships. The weight allocation is updated every 5 seconds.

9. A navigation and positioning terminal according to claim 2, characterized in that: The positioning terminal can analyze BeiDou positioning data in real time through a software platform and overlay electronic nautical charts to display the ship's motion trajectory. It outputs a quality control report that includes gross error marking, cycle slip detection, and multipath effect analysis. At the same time, it provides a centimeter-level position feedback interface that meets the requirements of a dynamic positioning system for marine engineering vessels.

Images