Unmanned cableless submersible and its polar ice region navigation and recovery safety guarantee method

Abstract

The application provides an unmanned and uncabled submersible and a polar ice region navigation and recovery safety guarantee method thereof, and relates to the field of deep diving devices. The method comprises the following steps: receiving an operation instruction, wherein the operation instruction comprises an operation execution stage; the operation execution stage comprises a diving stage, an operation stage and a navigation and recovery stage; in response to the operation instruction, performing the operation in the polar ice region based on the data of the sensors carried by the submersible and the operation execution stage; in the operation process, in response to the detection of an operation execution abnormality, performing a release operation corresponding to the operation execution stage; the release operation comprises at least one of releasing a throw-able buoyancy component through a first release mechanism, releasing an emergency position acoustic beacon through a second release mechanism and releasing diving ballast and / or floating ballast through a third release mechanism; the first release mechanism is driven by a de-energized electromagnet, and has magnetism when de-energized and loses magnetism when energized; the second and third release mechanisms are driven by a magnetism excitation electromagnet, and have magnetism when energized and lose magnetism when de-energized.

Description

Technical Field

[0001] This application relates to the field of deep-sea submersible devices, and more particularly to an unmanned, untethered submersible and a method for ensuring safety during navigation and recovery in polar ice areas. Background Technology

[0002] Submersible vehicles (DVs), as autonomous underwater vehicles, are widely used in marine environmental monitoring, resource exploration, and underwater engineering. However, DV operations involve various safety risks. For example, if the DV descends too quickly during deployment, it may collide with the seabed or ice; if the DV ascends too quickly during recovery, it may collide with the mother ship, causing the mother ship to capsize. Therefore, ensuring the safe operation of DVs is of paramount importance. Summary of the Invention

[0003] This application provides an unmanned, untethered submersible and a method for ensuring safety during navigation and recovery in polar ice areas, in order to at least solve the above-mentioned technical problems existing in the prior art.

[0004] According to a first aspect of this application, a method for ensuring the safety of unmanned, untethered submersible navigation and recovery in polar ice areas is provided, the method comprising: Receive a work instruction, which includes a work execution phase; the work execution phase includes a diving phase, a work phase, and a navigation and recovery phase. In response to the operation instructions, the system performs operations in the polar ice zone based on data from its onboard sensors and the operation execution phase. During the operation, in response to the detection of an operation execution abnormality, a release operation corresponding to the operation execution stage is performed; the release operation includes at least one of the following: releasing a jettisonable buoyancy component through a first release mechanism, releasing an emergency position indication beacon through a second release mechanism, and releasing submerged ballast and / or floating ballast through a third release mechanism. The first release mechanism is driven by a de-energized electromagnet, which is magnetic when de-energized and de-energized when energized; the second release mechanism and the third release mechanism are driven by an excitation electromagnet, which are magnetic when energized and de-energized when de-energized.

[0005] In one embodiment, the sensor includes at least one of the following: a water leakage sensor, a depth gauge, an altimeter, an ice bottom rangefinder, and a task timer.

[0006] In one possible implementation, when the operation execution phase is the diving phase, the operation based on onboard sensor data and the operation execution phase in the polar ice area includes: In polar ice regions, it relies on its own gravity to dive without power, and monitors the diving depth and the height from the bottom using the depth gauge and the altimeter. When the height above the bottom reaches a first set height threshold or the diving depth reaches the limit depth, the diving ballast is released by the third release mechanism; the limit depth is determined based on the maximum water depth in the operating area, and the limit depth is not greater than the design diving depth of the unmanned untethered submersible. In response to the completion of the ballast release during the submersion, the power system is activated to power the submersion to the set operating depth, thus entering the operating phase.

[0007] In one possible implementation, the step of performing a release operation corresponding to the job execution phase in response to detecting a job execution anomaly includes: During unpowered descent, in response to the detection of any of the following conditions, the third release mechanism simultaneously releases the descent ballast and the surfacing ballast: The water leakage sensor in any pressure chamber of the unmanned, untethered submersible continuously detects water leakage for a first set time. The vertical velocity exceeded the theoretical maximum diving speed value for a consecutive second set time period. The vertical velocity was determined based on the depth collected at different times in the preceding sequence.

[0008] In one possible implementation, the step of performing a release operation corresponding to the job execution phase in response to detecting a job execution anomaly further includes: After performing the release of submerged ballast, in response to detecting any of the following conditions, the submerged ballast and the floating ballast are released via the third release mechanism: The height from the bottom is less than or equal to the second set height threshold, and the rate of change of the vertical velocity compared with the velocity before the second set time does not exceed the first velocity change threshold. Within a second consecutive set time period, the difference between the depth gauge smoothing filter depth and the limit depth at different sampling times is greater than the first set depth change threshold.

[0009] In one possible implementation, when the job execution phase is the job phase itself, the step of performing a release operation corresponding to the job execution phase in response to detecting a job execution abnormality includes: In response to detecting any of the following conditions, the floating ballast is released via the third release mechanism: The leak sensor in any pressure chamber of the unmanned, untethered submersible continuously detects a leak for a first set time. The task timer has reached its maximum time limit; The depth change is less than the first depth change threshold, and the height from the bottom measured by the altimeter gradually decreases and remains in an invalid state for a third consecutive set period of time; Within a consecutive second set time period, the difference between the smoothed filtering depth of the depth gauge and the designed depth at different sampling times is greater than the second set depth change threshold.

[0010] In one possible implementation, when the operation execution phase is the navigation and recovery phase, the operation based on data from its onboard sensors and the operation execution phase in the polar ice region includes: In polar ice regions, the buoyancy ballast is released through the third release mechanism, and the heading and horizontal position are adjusted according to the position information fed back by the mother ship's Ultra-Short Baseline Positioning System (USBL) to perform unpowered buoyancy. When the ice rises to a depth within the first set threshold without power, and the distance to the ice bottom measured by the ice bottom rangefinder is less than the third set height threshold for a continuous second set time period, the throwable buoyancy component is released through the first release mechanism. After releasing the jettisonable buoyancy component, the power system is activated to navigate using a powered ascent method to find the recovery point; By measuring the slant distance, bearing, and elevation angle based on the ship's coordinate system using the mother ship's USBL, the position coordinates relative to the mother ship are obtained every four set time intervals. Based on these position coordinates, the ship is guided to move towards the recovery point until it enters the effective opening and closing angle range of the mother ship's USBL.

[0011] In one possible implementation, the step of performing a release operation corresponding to the job execution phase in response to detecting a job execution anomaly includes: In response to any of the following conditions, the emergency position beacon is released downwards to a third preset depth threshold via the second release mechanism, so that the emergency position beacon enters the effective opening and closing angle range of the mother ship USBL, allowing the mother ship USBL to receive the signal transmitted by the emergency position beacon to calculate the submersible's position, and to approach and recover the unmanned, untethered submersible based on the calculated submersible's position: After the buoyancy component is released, the ice bottom rangefinder measures that the height above the ice surface is less than the first set height threshold, and the rate of change of the current vertical velocity compared with the velocity before the second set time does not exceed the first velocity change threshold. During navigation, the depth change is less than the third set depth difference threshold within a second consecutive set time period, and the change in distance to the ice bottom measured by the ice bottom rangefinder is less than the first set distance change threshold within a second consecutive set time period. During navigation, the position opening angle of the unmanned untethered submersible is greater than half of the effective opening angle of the mother ship USBL. The position opening angle is determined based on the height and slant distance of the unmanned untethered submersible. A complete power failure was detected.

[0012] In one possible implementation, the emergency position beacon has an independent power supply.

[0013] According to a second aspect of this application, an unmanned, untethered underwater vehicle is provided, comprising: Hull; The first release mechanism, installed on the hull, is used to release the jettisonable buoyancy component. The first release mechanism is driven by a de-energized electromagnet, which is magnetic when de-energized and demagnetized when energized. The first release mechanism is installed above the center of gravity of the hull and is provided with a V-shaped guide groove to guide the jettisonable buoyancy component to avoid interference with the hull when it detaches. The second release mechanism, installed on the hull, is used to release the emergency position indicator beacon. The second release mechanism is driven by an excitation electromagnet, which is magnetic when energized and demagnetized when de-energized. The second release mechanism is embedded in the bottom of the hull, and the emergency position indicator beacon is connected to the hull via a connecting cable, the end of which is equipped with an anti-detachment limit. The third release mechanism, installed on the hull, is used to release submerged ballast and / or surfaced ballast; the third release mechanism is driven by an excitation electromagnet, which is magnetic when energized and demagnetized when de-energized; The main control unit, installed on the hull, is electrically connected to the first release mechanism, the second release mechanism, and the third release mechanism, and is used to execute the above-mentioned method for ensuring the safety of unmanned, untethered submersible navigation and recovery in polar ice areas.

[0014] The unmanned, untethered submersible and its method for ensuring safety during navigation and recovery in polar ice areas, as described in this application, can achieve the following beneficial technical effects: By adapting the release operation to the different stages of the operation and setting different electromagnet drive logic for different release mechanisms, the buoyancy state of the AUV is optimized and abnormal response is achieved in each stage of the operation. This balances the control accuracy during normal operation with the safety redundancy under abnormal conditions, effectively ensuring the safety and reliability of the entire AUV operation process.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0016] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of this application are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0017] Figure 1 This paper illustrates a schematic diagram of the implementation process of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in an embodiment of this application. Figure 2This paper illustrates the mechanism drive principle diagram of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in an embodiment of this application; Figure 3 This paper illustrates the operational flow diagram of the unmanned untethered submersible's descent phase in the safety assurance method for navigation and recovery of unmanned untethered submersibles in polar ice areas provided in the embodiments of this application. Figure 4 This illustration shows a schematic diagram of the ballast release operation of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in the embodiments of this application; Figure 5 This paper illustrates a schematic diagram of the operation process of the unmanned untethered submersible navigation and recovery phase in the polar ice area safety assurance method provided in the embodiments of this application. Figure 6 This paper illustrates a schematic diagram of the operational process for the navigation and recovery phases of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in an embodiment of this application. Figure 7 This illustration shows an anomaly handling operation during the navigation and recovery phase of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in the embodiments of this application. Figure 8 This illustration shows a schematic diagram of the implementation process of a specific application example of the safety assurance method for unmanned, untethered submersible navigation and recovery in polar ice areas provided in the embodiments of this application. Detailed Implementation

[0018] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] First, the application scenarios of this application are explained. During submersible operations, the following problems typically exist: 1) Regarding buoyancy control, to improve the safety of the submersible surfacing from the seabed, it is usually equipped with a large positive buoyancy. However, a large positive buoyancy increases the difficulty of motion control and power consumption when the submersible is searching for an surfacing point near the ice bottom, which is detrimental to safe recovery. 2) Regarding positioning assurance, a positioning acoustic beacon is usually installed on the top of the submersible, and positioning is achieved through the mother ship's ultra-short baseline positioning system. However, in ice-covered environments, if the submersible fails to surface and becomes stuck on the ice bottom, the uneven ice ridges can easily block the beacon signal, or the angle between the beacon and the surface array may be too large, making it difficult for the positioning system to accurately locate the submersible and easily leading to its loss. 3) Regarding the release mechanism's drive logic, existing technologies typically use a single electromagnet drive method, without differentiating the design based on the functional differences of different components. For example, if the jettisonable buoyancy components automatically release during a power outage, it may lead to excessive positive buoyancy and loss of control of the submersible; if the emergency beacon or ballast fails to release during a power outage, it may cause the submersible to lose its positioning ability or be unable to surface. Therefore, to address the above problems, this application provides a method for ensuring the safety of unmanned untethered submersible navigation and recovery in polar ice areas, as well as an unmanned untethered submersible.

[0020] Figure 1 This paper illustrates a schematic diagram of the implementation process of the safety assurance method for unmanned, untethered submersible navigation and recovery in polar ice areas provided in an embodiment of this application.

[0021] refer to Figure 1 This application first provides a method for ensuring the safety of unmanned, untethered submersible navigation and recovery in polar ice areas, the method comprising: Operation 101: Receive the operation instructions, which include the operation execution phase; the operation execution phase includes the diving phase, the operation phase, and the navigation and recovery phase.

[0022] The method described in this application utilizes an Autonomous Underwater Vehicle (AUV). An AUV is a submersible that autonomously completes underwater navigation and operations using its own onboard power and control systems. It does not require a cable connection to a mother ship and can autonomously navigate within a predetermined area, performing tasks such as underwater exploration and observation. The AUV's operational process is typically divided into three phases: the diving phase, the operational phase, and the navigation and recovery phase. The diving phase refers to the process where the AUV, after being deployed from a surface mother ship (icebreaker), descends to the predetermined working depth using its own gravity or power system. The operational phase refers to the process where the AUV performs underwater exploration and observation tasks within the predetermined working depth or area. The navigation and recovery phase refers to the process where, after completing its mission or receiving a return command, the AUV surfaces from its working depth, locates a recovery point (such as an ice well), and is recovered by the mother ship.

[0023] Before deployment, the mother ship sends operational instructions to the AUV via underwater acoustic communication or pre-loading. In addition to information on the aforementioned operational phases, these instructions may also carry operational parameters, such as the maximum mission time, design diving depth, return route, and recovery point location, to guide the AUV's operational behavior at each stage.

[0024] Operation 102, in response to the operation command, conducts operations in the polar ice zone based on data from its onboard sensors and the stage of the operation.

[0025] According to the operational instructions, the AUV uses its onboard sensor data to perform the corresponding operational control in the polar ice region for each operational phase. For example, during the diving phase, it adjusts its diving state based on sensor data; during the operational phase, it maintains its operational state based on sensor data; and during the navigation and recovery phase, it adjusts its buoyancy and navigation state based on sensor data to locate the recovery point and await recovery by the mother ship.

[0026] Among them, the polar ice zone refers to the polar sea areas in the Arctic, Antarctic and surrounding areas where there is sea ice cover (including fixed ice and floating ice), operations can be carried out by icebreaker mother ships, and ice wells / moon pools can be deployed and retrieved. The core characteristics of this area are the presence of ice surface / ice bottom barriers and the need for navigation and operations under ice.

[0027] Operation 103: During the operation, in response to the detection of an abnormality in the operation execution, a release operation corresponding to the operation execution stage is executed; the release operation includes at least one of releasing a throwable buoyancy component through a first release mechanism, releasing an emergency position signal beacon through a second release mechanism, and releasing submerged ballast and / or floating ballast through a third release mechanism; wherein, the first release mechanism is driven by a de-energized electromagnet, which is magnetic when de-energized and de-energized when energized; the second release mechanism and the third release mechanism are driven by an excitation electromagnet, which are magnetic when energized and de-energized when de-energized.

[0028] Different risks exist in each phase of the operation. During the descent phase, if the AUV loses control of its descent speed due to water leakage or the detachment of buoyancy components, it may crash into the seabed or ice. During the operation phase, if the AUV leaks water, exceeds the mission time limit, touches the bottom, or goes too deep, it may cause equipment damage or mission failure. During the navigation and recovery phase, if the AUV's positioning signal is interrupted, it becomes stuck on the ice and cannot move, or the entire machine loses power, it may be lost.

[0029] To this end, this application equips the AUV with a first release mechanism, a second release mechanism, and a third release mechanism. The first release mechanism is used to release a jettisonable buoyancy component, which is a jettisonable object made of buoyancy material. After release, the net buoyancy of the AUV decreases, enabling low-speed, low-energy controllable navigation in near-ice-bottom areas. The second release mechanism is used to release an emergency position beacon, which continuously transmits acoustic signals after release for the mother ship's positioning system to receive. The third release mechanism is used to release submerging ballast and / or surfacing ballast. The submerging ballast is used to enable the AUV to gain positive buoyancy and rise, while the surfacing ballast is used to adjust the AUV from a large positive buoyancy to neutral buoyancy for operation.

[0030] In the event of an anomaly, the AUV can combine control of the first, second, and third release mechanisms according to the current operational phase, executing release operations corresponding to the current phase to ensure safe operation. For example, if leakage or abnormal vertical velocity is detected during the diving phase, the third release mechanism simultaneously releases the diving ballast and the buoyancy ballast, while the second release mechanism releases the emergency position beacon, enabling the AUV to quickly surface and acquire position information. If leakage, mission timeout, bottoming out, or excessive depth is detected during the operational phase, the third release mechanism releases the buoyancy ballast, and the second release mechanism releases the emergency position beacon, enabling the AUV to gain positive buoyancy, surface, and acquire position information. If positioning interruption, ice floe entrapment, or overall power failure is detected during the navigation and recovery phase, the second release mechanism releases the emergency position beacon, bringing the beacon into the effective reception range of the mother ship's positioning system and restoring position measurement.

[0031] Figure 2 The diagram illustrates the mechanism drive principle of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in this application embodiment.

[0032] In one embodiment of this application, the first release mechanism is driven by a de-energized electromagnet, which is magnetic when power is off and demagnetized when power is on; the second and third release mechanisms are driven by energized electromagnets, which are magnetic when power is on and demagnetized when power is off. The emergency position indication sound beacon has an independent power supply.

[0033] Specifically, refer to Figure 2 To ensure the safety of different components in the event of a power outage, this application employs differentiated drive logic designs for the three release mechanisms. The first release mechanism, used to release the jettisonable buoyancy component, is driven by a de-energized electromagnet. In the power-off state, the electromagnet retains its magnetism, attracting the release mechanism and locking it in a locked state. Release is only achieved when energized. This design prevents the AUV from accidentally jettisoning the jettisonable buoyancy component when the entire unit is powered off, preventing uncontrolled buoyancy or impact with surface structures due to excessive positive buoyancy, thus ensuring the controllability of the buoyancy component release.

[0034] The second release mechanism is used to release the emergency position beacon, and the third release mechanism is used to release the submerged and surfaced ballast. Both are driven by excitation electromagnets, meaning that the electromagnets remain magnetic and lock the release mechanism when energized, and only demagnetize and release when power is cut off. This design ensures that the emergency position beacon and ballast can be automatically released when the entire system is powered off: after the beacon is released, its independent power supply immediately starts working, continuously transmitting position information for the mother ship's positioning system to receive; after the surfaced ballast is released, the AUV gains significant positive buoyancy and can immediately rise to near the surface to await recovery.

[0035] Thus, the three release mechanisms form a complementary safety logic. The first release mechanism remains locked when power is off, avoiding the risk of loss of control caused by accidental ejection of buoyancy components. The second and third release mechanisms automatically release when power is off, ensuring the AUV's positioning and buoyancy capabilities in abnormal situations. This balances controllability during normal operation with safety redundancy in abnormal situations, effectively ensuring the safety and reliability of the entire AUV operation process.

[0036] Among them, the first release mechanism, the second release mechanism and the third release mechanism are all controlled by the AUV, and the excitation power of their electromagnets is provided by the AUV's system power supply.

[0037] Furthermore, the emergency position indication beacon has its own independent power supply. When the AUV is trapped on the ice or experiences communication or power supply abnormalities, even if the AUV system power fails, the beacon can still be released normally and continuously transmit position information. Combined with the icebreaker mother ship's Ultra-Short Baseline (USBL) positioning system, the mother ship can receive the beacon signal, achieving relatively accurate and rapid acquisition of the AUV's position, providing support for subsequent guidance and surfacing.

[0038] In one embodiment of this application, the buoyancy ballast, the submersion ballast, the jettisonable buoyancy components, and the emergency position signal beacon are all pre-attached to the AUV before deployment.

[0039] Thus, the embodiments of this application adapt the release operation according to the operation execution stage and set different electromagnet drive logic for different release mechanisms, thereby realizing the optimization of buoyancy status and abnormal response of AUV in each operation stage, taking into account the control accuracy during normal operation and the safety redundancy under abnormal conditions, effectively ensuring the safety and reliability of the entire AUV operation process, especially ensuring the safety of unmanned untethered submersible navigation and recovery in polar ice areas.

[0040] In one embodiment of this application, the sensor includes at least one of the following: a water leakage sensor, a depth gauge, an altimeter, an ice bottom rangefinder, and a mission timer. The water leakage sensor is installed in each pressure chamber of the AUV to detect whether water has entered the chamber, providing a basis for determining whether the submersible has a risk of seal failure. The depth gauge measures the current seawater depth of the AUV, providing real-time data for depth control during descent, operation, and ascent phases. The altimeter (downward rangefinder) measures the vertical distance between the AUV and the seabed or obstacles below, primarily used to prevent bottom contact during descent and operation phases. The ice bottom rangefinder (also known as an upward rangefinder) measures the vertical distance between the AUV and the bottom of the ice layer above, primarily used to determine whether it is approaching the ice bottom during navigation and recovery phases. The mission timer records the duration of the AUV's current operational task, providing a time reference for duration control during the operation phase.

[0041] Figure 3 This illustration shows a schematic diagram of the operation process of the unmanned untethered submersible during the descent phase of the safety assurance method for navigation and recovery of unmanned untethered submersibles in polar ice areas provided in the embodiments of this application.

[0042] refer to Figure 3 In one embodiment of this application, when the operation execution phase is the diving phase, the above-mentioned operation 102, based on the data from its own onboard sensors and the operation execution phase, is carried out in the polar ice area, including: Operation 200, in the polar ice zone, relies on its own gravity to dive without power, and monitors the diving depth and the height from the bottom through depth gauge and altimeter; Operation 210: When the height above the bottom reaches the first set height threshold or the diving depth reaches the limit depth, the diving ballast is released through the third release mechanism; the limit depth is determined based on the maximum water depth in the operating area, and the limit depth is not greater than the design diving depth of the unmanned untethered submersible. Operation 220: In response to the completion of the ballast release during submersion, the power system is activated to power the submersion to the set operating depth, and the operation phase begins.

[0043] Specifically, when the unmanned, untethered underwater vehicle (AUV) is in the descent phase in polar ice areas, it first descends without power, relying on its own gravity. During the descent, the depth gauge monitors the current descent depth in real time, and the altimeter monitors the vertical distance from the seabed in real time. When the altimeter-measured height from the bottom reaches a first preset height threshold (e.g., 100m), or when the depth gauge-measured current depth reaches its limit, the AUV releases the ballast via a third release mechanism, adjusting the AUV's buoyancy to neutral. After the ballast is released, the AUV activates its propulsion system and continues to descend to the preset operating depth in a powered manner, then enters the operational phase to perform underwater exploration or observation tasks. Through the above operations, the AUV achieves a smooth transition from surface deployment to the operating depth, laying the foundation for stable operation in subsequent operational phases.

[0044] The "limit depth" refers to the maximum depth the AUV is permitted to dive during this operation. This limit depth can be determined based on the maximum water depth within the operational area as measured by the multibeam echo sounder carried by the mother ship, and can be expressed as follows: That is, the maximum water depth within the operating area. The depth after deducting the safety margin, and this limit depth not exceeding the AUV's design diving depth, ensures that the AUV will not be damaged due to excessive depth. The design diving depth refers to the maximum diving depth that the AUV can safely withstand structurally, i.e., the limit depth at which the AUV body and internal equipment will not suffer structural damage or functional failure under seawater pressure. When determining the limit depth, it is necessary to ensure that the maximum water depth in the operating area does not exceed the AUV's design diving depth, thereby guaranteeing the structural safety of the AUV when diving to the deepest point in the operating area.

[0045] In one embodiment of this application, during the descent phase, the above-mentioned operation 103, in response to detecting an abnormality in the operation execution, performs a release operation corresponding to the operation execution phase, including: during the unpowered descent, in response to detecting any of the following situations, simultaneously releasing the descent ballast and the surfacing ballast through the third release mechanism: a water leakage sensor in any pressure chamber on the unmanned untethered submersible detects water leakage for a first set duration; the vertical velocity exceeds the theoretical maximum descent velocity value for a second set duration, the vertical velocity being determined based on the depth collected at different previous times.

[0046] Specifically, during the AUV's unpowered descent, leakage sensor signals and vertical velocity are monitored in real time. The vertical velocity is calculated from depth values ​​collected by a depth gauge at different times; for example, the current vertical velocity can be estimated based on depth changes at previous sampling times, and can be expressed as follows: , For the current depth, The depth of the previous moment. The sampling interval is defined as follows. Leakage sensors are installed in each pressure chamber. When water enters any pressure chamber, the leakage sensor continuously detects a leakage signal for a first set duration (e.g., 2 seconds), indicating a risk of seal failure for the AUV. The vertical velocity calculated within a second set duration (e.g., 5 seconds) is then used to determine the leakage rate. All exceeded the theoretical maximum diving speed. This indicates that the AUV may be descending too quickly due to reasons such as accidental detachment of buoyancy components, posing a risk of impacting the seabed or ice. When any of the above abnormalities are detected, the third release mechanism will immediately release the descent ballast and ascent ballast simultaneously, giving the AUV greater positive buoyancy and allowing it to quickly rise to near the surface, thus avoiding equipment damage due to loss of control during descent.

[0047] In one embodiment of this application, in addition to monitoring for abnormal situations during unpowered descent, the AUV continues to monitor relevant status data after the ballast jettisoning operation is performed to determine whether the ballast jettisoning was successfully completed and whether the descent depth is within a safe range. Accordingly, during the descent phase, in response to detecting an operational anomaly, a release operation corresponding to the operational phase is performed, further including: after performing the ballast jettisoning operation, in response to detecting any of the following conditions, the ballast jettisoning and buoyancy ballast are released via a third release mechanism: the height from the bottom is less than or equal to a second preset height threshold, and the rate of change of vertical velocity compared to the velocity before a second preset time period does not exceed a first velocity change threshold; the difference between the smoothed-filter depth and the ultimate depth at different sampling times within a consecutive second preset time period is greater than a first preset depth change threshold.

[0048] Specifically, after the AUV performs the ballast release operation, the altitude above the bottom, vertical velocity, and current depth are continuously monitored. If the altitude above the bottom has decreased to below the second preset altitude threshold (e.g., 80m), but the rate of change of the current vertical velocity compared to the velocity two preset time intervals (e.g., 5s) does not exceed the first velocity change threshold (e.g., 10%), it indicates that the ballast release has failed, and the AUV continues to sink at a non-powered descent speed, posing a risk of impacting the seabed or ice. Furthermore, if the difference between the smoothed filtered depth and the ultimate depth collected by the depth gauge is greater than the first preset depth change threshold (e.g., 20m) for a continuous second preset time interval (e.g., 5s), it indicates that the AUV has exceeded the preset safe ballast jettison depth, posing a risk of over-depth.

[0049] Therefore, when any of the above situations are detected, the third release mechanism simultaneously releases both the submersible ballast and the buoyancy ballast, giving the AUV greater positive buoyancy and allowing it to quickly rise to near the surface, thus avoiding equipment damage caused by ballast failure or excessive depth. Through this graded anomaly detection mechanism, the AUV effectively covers various abnormal scenarios during the submersible phase, further improving operational safety.

[0050] Figure 4 This illustration shows a schematic diagram of the ballast release operation of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in the embodiments of this application.

[0051] To facilitate understanding of the submerged ballast and floating ballast release process in this application, the following is combined with... Figure 4 Please provide an explanation. (Reference) Figure 4 The diagram illustrates the AUV 100, its third release mechanism 151, and the released submersible ballast 152 and buoyancy ballast 153. The third release mechanism 151 controls the release of the submersible and buoyancy ballasts; the submersible ballast 152 is released after the AUV completes a powerless dive, adjusting its buoyancy to neutral; the buoyancy ballast 153 is released in abnormal situations or during return voyages, allowing the AUV to gain greater positive buoyancy and rise rapidly. The diagram also shows the effective opening angle (e.g., 120°) of the mother ship's ultra-short baseline positioning system, within which the AUV can be accurately positioned.

[0052] When an anomaly occurs during the AUV's descent phase (such as water leakage or loss of vertical velocity control), the third release mechanism 151 simultaneously releases the descent ballast 152 and the buoyancy ballast 153, allowing the AUV to gain significant positive buoyancy and rise rapidly, avoiding impact with the seabed or ice. If ballast jettisoning fails after the AUV has performed the descent ballast release operation (e.g., the height above the bottom is less than or equal to a second preset height threshold and the rate of change of vertical velocity does not exceed the threshold, or the depth exceeds the limit), the third release mechanism 151 again simultaneously releases the descent ballast 152 and the buoyancy ballast 153, allowing the AUV to quickly rise to near the surface. Through this configuration, this application achieves rapid response to anomalies during ballast release, further ensuring the operational safety of the AUV.

[0053] In one embodiment of this application, when the operation execution phase is the operation phase, the AUV has completed its dive and entered the predetermined working depth to perform an underwater exploration mission. During this process, various status data are continuously monitored to identify abnormal situations that may endanger operational safety. The above-mentioned operation 103, in response to the detection of an operational abnormality, performs a release operation corresponding to the operation execution phase, including: in response to the detection of any of the following situations, releasing the buoyancy ballast through the third release mechanism: a water leakage sensor in any pressure chamber of the unmanned untethered submersible detects water leakage for a first set duration; the mission timer reaches its maximum time limit; the depth change is less than a first depth change threshold, and the height from the bottom measured by the altimeter gradually decreases and remains in an invalid state for a third set duration; the difference between the smoothed filtered depth of the depth gauge and the designed diving depth is greater than a second set depth change threshold at different sampling times within a second set duration.

[0054] Specifically, during the operation phase, the AUV continuously performs underwater detection tasks, monitoring leak sensor signals, task timers, depth changes, height above the bottom, and current depth in real time. When a leak sensor in any pressure chamber detects a leak signal for a first set duration (e.g., 2 seconds), it indicates that the AUV is at risk of sealing failure, and continued operation may lead to equipment damage. When the task timer reaches the preset maximum time limit, it indicates that the operation has timed out, and the AUV should surface in time to avoid energy depletion or equipment overload. When the depth change is less than the first depth change threshold, and the height above the bottom measured by the altimeter gradually decreases and remains invalid for a third set duration (e.g., 30 minutes), it indicates that the AUV may have touched the bottom, and continued diving or operation carries the risk of impact with the seabed. When the difference between the smoothed filtered depth collected by the depth gauge and the designed diving depth is greater than the second set depth threshold (e.g., 30m) for a second set duration (e.g., 5 seconds), it indicates that the AUV has exceeded the designed diving depth and is at risk of over-depth.

[0055] Therefore, when any of the above-mentioned anomalies is detected, the buoyancy ballast is immediately released via the third release mechanism, allowing the AUV to gain significant positive buoyancy and quickly rise to near the water surface, thus promptly escaping the danger zone and ensuring equipment safety. Through the coordinated operation of these multiple anomaly detection mechanisms, the AUV achieves effective identification and rapid response to various potential risks during operation, further enhancing operational safety and reliability.

[0056] Figure 5 This illustration shows a schematic diagram of the operation process of the unmanned untethered submersible navigation and recovery phase in the safety assurance method for polar ice area navigation and recovery of unmanned untethered submersibles provided in the embodiments of this application.

[0057] refer to Figure 5 When the operation execution phase is the navigation and recovery phase, the above operation 102, based on the data from its onboard sensors and the operation execution phase, conducts operations in the polar ice area, including: Operation 300: In the polar ice zone, release the buoyancy ballast through the third release mechanism, and adjust the heading and horizontal position according to the position information fed back by the mother ship's Ultra-Short Baseline Positioning System (USBL) to perform unpowered buoyancy; Operation 310: When the ice rises to the first set depth threshold without power, and the distance to the ice bottom measured by the ice bottom rangefinder is less than the third set height threshold for a continuous second set time period, the throwable buoyancy component is released through the first release mechanism. Operation 320: After releasing the jettisonable buoyancy components, activate the propulsion system to navigate using powered ascent and search for the recovery point. Operation 330: The slant distance, bearing, and elevation angle measured by the mother ship's USBL based on the ship's coordinate system are converted and obtained relative to the mother ship's position coordinates every four set intervals. Based on the position coordinates, the ship moves towards the recovery point until it enters the effective opening and closing angle range of the mother ship's USBL.

[0058] Specifically, after the AUV completes its underwater mission in the polar ice region or receives a surface surfacing command, it first releases the surfacing ballast via the third release mechanism, giving the AUV positive buoyancy and initiating unpowered ascent. During the ascent, the AUV receives position information from the mother ship USBL and continuously adjusts its heading and horizontal position based on the horizontal coordinates of the mother ship USBL and its own horizontal coordinates, gradually bringing the horizontal distance between the AUV and the mother ship USBL closer to zero, satisfying the following relationship:

[0059] in, , This represents the horizontal position coordinate of the mothership's USBL at time i. , This represents the horizontal position coordinates of the AUV at time i. This represents the horizontal distance between the AUV and the USBL at time i. Through the above adjustments, it is ensured that the AUV can maintain a general direction towards the mother ship during the unpowered ascent phase.

[0060] When the AUV rises without power to a depth threshold of 100m, it indicates that the AUV has entered shallow water. During this process, the AUV continuously monitors the distance to the ice layer above using an ice bottom rangefinder. When the distance to the ice bottom measured by the ice bottom rangefinder is less than a third set height threshold (e.g., 50m) for a consecutive second set time period (e.g., 5s), it indicates that the AUV has entered the near-ice bottom area. At this time, the AUV releases its jettisonable buoyancy components through a first release mechanism to reduce its positive buoyancy and improve the controllability of navigation near the ice bottom.

[0061] After releasing the buoyancy components, the AUV activates its propulsion system and switches to powered navigation mode, navigating at low speed and low power consumption to locate a recovery point (such as an ice well). During this search, the AUV receives slant range, bearing, and elevation data from the mother ship's USBL. Every four predetermined intervals (e.g., 14 seconds), it converts this data to its own position coordinates relative to the mother ship and uses these coordinates to guide its movement towards the recovery point until the AUV enters the effective opening and closing angle range of the mother ship's USBL, preparing for subsequent recovery. Through this process, the AUV achieves a smooth transition from unpowered ascent to powered near-ice-bottom navigation during the navigation and recovery phases, ensuring safety during ascent and improving control accuracy in locating the recovery point near the ice bottom.

[0062] Figure 6 This paper illustrates a schematic diagram of the operational process for the navigation and recovery phases of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in an embodiment of this application.

[0063] To facilitate understanding of the operational procedures during the navigation and recovery phases of this application, the following is a summary... Figure 6 Please provide an explanation. (Reference) Figure 6 The mother ship 201 uses the ultra-short baseline positioning system 202 to locate the AUV 100, and the ice well or inter-ice channel 301 serves as the recovery point for the AUV 100. The AUV 100 is equipped with an underwater positioning acoustic beacon 120, an ice bottom rangefinder 130, an altimeter 160, a jettisonable buoyancy component 111, and its first release mechanism 112. The underwater positioning acoustic beacon 120 works in conjunction with the mother ship's ultra-short baseline positioning system 202 to measure the AUV 100's underwater position; the ice bottom rangefinder 130 measures the vertical distance between the AUV 100 and the bottom of the ice layer above; and the altimeter 160 measures the vertical distance between the AUV and the seabed or obstacles below.

[0064] After the AUV 100 completes its underwater mission or receives a return command, in order to surface from its operating depth, it first releases the buoyancy ballast via the third release mechanism, allowing the AUV 100 to gain positive buoyancy and begin unpowered ascent. During the ascent, to determine the AUV 100's vertical position and relative distance to the ice layer, it uses an underwater positioning acoustic beacon 120 in conjunction with the mother ship's ultra-short baseline positioning system 202 for positioning, and an ice bottom rangefinder 130 to monitor the distance to the ice layer above. When the AUV surfaces to a shallow water area (e.g., depth less than 100m) and the distance to the ice bottom measured by the ice bottom rangefinder 130 is less than a preset threshold (e.g., 80m), it indicates that the AUV 100 has entered the near-ice bottom area. At this point, to reduce positive buoyancy to improve the controllability of near-ice bottom navigation and reduce energy consumption when searching for a recovery point near the ice bottom, the AUV 100 releases the jettisonable buoyancy component 111 via the first release mechanism 112. After releasing the buoyancy components, in order to accurately adjust its position to find the recovery point, the AUV starts the power system and switches to powered navigation mode. Guided by the mother ship's ultra-short baseline positioning system 202, it searches for the recovery point until the AUV 100 enters the effective opening and closing angle range of the mother ship's ultra-short baseline positioning array.

[0065] In one embodiment of this application, during the navigation and recovery phase, the above-mentioned operation 103, in response to detecting an operational anomaly, performs a release operation corresponding to the operational phase, including: in response to detecting any of the following conditions, releasing the emergency position beacon downward to a third preset depth threshold via a second release mechanism, so that the emergency position beacon enters the effective opening and closing angle range of the mother ship USBL, allowing the mother ship USBL to receive the signal sent by the emergency position beacon to calculate the submersible's position, and recovering the unmanned untethered submersible based on the calculated submersible's position: releasing buoyancy components. Subsequently, the ice bottom rangefinder measured a height above the ice surface that was less than a first set height threshold, and the rate of change of the current vertical velocity compared to the velocity before the second set time period did not exceed the first velocity change threshold; during navigation, the depth change within the second set time period was less than a third set depth difference threshold, and the change in distance from the ice bottom measured by the ice bottom rangefinder within the second set time period was less than the first set distance change threshold; during navigation, the unmanned untethered submersible's position opening angle was greater than half of the effective opening angle of the mother ship's USBL, and the position opening angle was determined based on the unmanned untethered submersible's altitude and slant distance; a power failure of the entire machine was detected.

[0066] Specifically, during the navigation and recovery phase, the AUV enters powered navigation mode after releasing its buoyancy components, searching for a recovery point (such as an ice well) near the ice bottom. Due to the high vertical speed during unpowered ascent, the accuracy of the USBL positioning and the horizontal position control of the AUV is poor. Combined with the influence of environmental factors such as ocean currents and wind, it is difficult for the AUV to return directly to the recovery point from the seabed. Therefore, it needs to conduct near-ice-bottom depth-controlled navigation under the guidance of the USBL. During this process, the AUV continuously monitors various status data to identify any abnormalities that may affect the safety of the recovery.

[0067] The AUV determines that it needs to release the emergency position beacon under any of the following conditions: 1) If, after releasing the buoyancy component, the ice bottom rangefinder measures a height from the ice surface that is less than a first set height threshold (e.g., 100m), and the current vertical velocity... Speed ​​5 seconds ago The rate of change compared to the first velocity change threshold (e.g., 10%) does not exceed the threshold value. This indicates that although the AUV has jettisoned its buoyancy components, it has not effectively reduced its ascent speed, posing a risk of getting stuck on the ice bottom.

[0068] 2) If the AUV touches the ice bottom, that is, the depth is measured at different sampling times within a second consecutive set time period (e.g., 5 seconds). Sampling depth from the previous time step The difference is less than the third preset depth difference threshold (e.g., 2m), and the distance to the ice bottom measured by the ice bottom rangefinder within the second preset time period (e.g., 5s) is... The change is less than the first set distance change threshold (e.g., 2m), that is... and This indicates that the vertical position of the AUV and the distance measurement height under the ice are abnormally different, the altimeter may be blocked by the ice, and the AUV is trapped under the ice and unable to move.

[0069] 3) If the AUV has deviated from the effective opening angle of the USBL. Specifically, the USBL on the hull measures the relative position data of the AUV based on the hull coordinate system. ), of which slant distance ,position Angle of elevation The position coordinates relative to the mother ship are obtained at set intervals (e.g., 14 seconds) through geometric transformation: , , USBL effective opening angle The height of the AUV is slant distance is Then the AUV position opening angle , When the AUV position opening angle When this occurs, it indicates that the AUV has deviated from the effective opening angle of the USBL, and the USBL positioning signal may be unstable or interrupted at this time.

[0070] 4) Power failure of the entire machine was detected.

[0071] When any of the above conditions are detected, the AUV immediately releases the emergency position beacon downwards to a third preset threshold depth (e.g., 30m) via the second release mechanism, bringing the emergency position beacon within the effective opening and closing angle range of the mother ship's USBL. The mother ship's USBL receives the signal transmitted by the emergency position beacon, thus obtaining the accurate AUV slant range again. The system calculates the submersible's position, and the mother ship moves along the direction of the maximum rate of change of slant range based on the calculation results, approaching the AUV to perform ice surface recovery operations. Through the above-mentioned anomaly detection and emergency beacon release mechanism, this application achieves effective coverage of various abnormal scenarios during the navigation and recovery phases, further improving the safety and reliability of AUV recovery.

[0072] Figure 7 This diagram illustrates the anomaly handling operations during the navigation and recovery phase of the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas provided in this application embodiment.

[0073] To further understand the handling procedures for anomalies during the navigation and recovery phases outlined in this application, the following is in conjunction with the appendix. Figure 7 For explanation and reference Figure 7When an anomaly occurs during the navigation and recovery phases of the AUV, obstacles (such as ice ridges) 302 may obstruct the regular positioning signal. An emergency position beacon 144 is embedded in the bottom of the AUV. This beacon is connected to the beacon frame 143 via a beacon release cable 142 and is released by an emergency position beacon release mechanism 141. The emergency position beacon release mechanism 141, also known as the second release mechanism, is used to release the emergency position beacon 144 in abnormal situations. The emergency position beacon 144 has an independent power supply and can operate normally when the AUV system is powered off.

[0074] When the AUV detects any of the following abnormalities: remaining stuck on the ice after releasing the buoyancy component (the ice bottom rangefinder measures a height from the ice surface less than a preset threshold and the rate of change of vertical velocity does not exceed the threshold), touching the ice bottom (both the change in depth and the change in distance from the ice bottom are less than the threshold), deviating from the effective opening angle of the USBL (position opening angle greater than half of the effective opening angle), or the entire unit loses power, the AUV will release the emergency position beacon 144 downwards via the second release mechanism. After release, the emergency position beacon 144 is suspended below the AUV via the beacon release cable 142, bringing it into the effective receiving opening angle range of the mother ship's USM (Ultra-Short Baseline) positioning system. The mother ship receives the beacon signal and calculates the AUV's position, thereby guiding the mother ship to approach the AUV for recovery.

[0075] Figure 8 This illustration shows a schematic diagram of the implementation process of a specific application example of the safety assurance method for unmanned, untethered submersible navigation and recovery in polar ice areas provided in the embodiments of this application.

[0076] To further understand the technical solution of this application, a specific application example is given below.

[0077] refer to Figure 8 This application provides a specific example of a safety assurance method for the navigation and recovery of unmanned untethered submersibles (AUVs) in polar ice areas, also known as a safety assurance strategy for the navigation and recovery of AUVs in polar ice areas. This method is primarily applied to AUV navigation and recovery operations in polar ice environments. In this scenario, the icebreaker mother ship deploys the AUV to the sub-ice waters through ice wells (circular openings in the ice layer for AUV deployment and recovery). The AUV performs underwater exploration tasks in the water between the ice and the seabed and ultimately returns to the ice well for recovery. The specific operational process is as follows: 1) During the descent phase, the AUV is deployed from the icebreaker mother ship along the ice well into the polar ice zone, and the "AUV descent" process begins.

[0078] If an anomaly occurs during the descent (such as the leakage sensor continuously detecting leakage, or the vertical velocity continuously exceeding the theoretical maximum descent speed), the following actions will be executed: "① jettisoning descent and surfacing ballast; ② releasing emergency position beacon". This means that the descent ballast and surfacing ballast will be released simultaneously through the third release mechanism, and the emergency position beacon will be released through the second release mechanism. This will enable the AUV to obtain greater positive buoyancy and rise rapidly, while providing position information through the beacon to ensure the safety of the AUV.

[0079] If no abnormalities occur during the descent, the "normal ballast jettison" will be performed to adjust the buoyancy to neutral, and then the "AUV underwater operation" phase will begin.

[0080] 2) During the operation phase, the AUV performs underwater exploration tasks at the preset operating depth and enters the "AUV underwater operation" process.

[0081] If any abnormality occurs during operation (such as water leakage, mission timeout, bottoming out, or excessive depth), the following actions will be taken: "① jettisoning buoyancy; ② releasing emergency position beacon". This means releasing the buoyancy ballast through the third release mechanism and releasing the emergency position beacon through the second release mechanism, so that the AUV can obtain greater positive buoyancy and rise quickly. At the same time, the beacon provides position information to ensure the safety of the AUV.

[0082] If no abnormalities occur during the operation, the mission will continue until the mission is completed or a return instruction is received. Then, the "normal jettisoning of ballast" will be performed, so that the AUV can obtain positive buoyancy and begin to rise without power, entering the "AUV rising" stage.

[0083] 3) Navigation and recovery phase.

[0084] After the AUV enters the "AUV Ascent" process, it monitors the distance to the ice layer above in real time using an ice bottom rangefinder and makes a judgment: if the distance to the ice bottom is greater than a preset threshold, it continues to ascend; if the distance to the ice bottom is less than or equal to the preset threshold (e.g., 80m), it indicates that the AUV has entered the near-ice bottom area, and then releases the buoyancy component, that is, releases the jettisonable buoyancy component through the first release mechanism to reduce positive buoyancy and improve the controllability of navigation near the ice bottom, and then enters the autonomous ice well search process.

[0085] During the autonomous search for the ice well, the AUV activates its propulsion system, switches to powered navigation mode, and searches for the ice well under the guidance of the mother ship USBL. If the ice well is successfully located, the AUV autonomously surfaces from the ice well and is recovered.

[0086] If any of the following situations occur during the search for the ice well: ① Unable to reach the bottom of the ice well (during navigation, the depth change is less than the third set depth difference threshold within a second consecutive set time period, and the change in distance from the ice bottom measured by the ice bottom rangefinder is less than the first set distance change threshold within a second consecutive set time period); ② Unstable or interrupted positioning guidance information (during navigation, the unmanned underwater vehicle's position opening angle is greater than half of the effective opening angle of the mother ship's ultra-short baseline positioning system); ③ Stuck on the ice bottom (after releasing the buoyancy components, the height above the ice surface measured by the ice bottom rangefinder is less than the first set height threshold, and the rate of change of the current vertical velocity compared to the velocity before the second set time period does not exceed the first velocity change threshold); ④ AUV malfunction, such as power failure (detection of a complete power failure). The AUV releases an emergency position beacon, lowering it to a preset depth (e.g., 30m) to bring it within the effective receiving angle range of the mother ship's USBL. The mother ship then calculates the AUV's position based on the emergency position beacon and proceeds for rescue. Once close to the AUV, reopen the ice hole and use ROV (Remotely Operated Vehicle) or other auxiliary means to pull the AUV out of the water and complete the recovery.

[0087] As can be seen from the above specific application examples, the method for ensuring the safety of unmanned, untethered submersible navigation and recovery in polar ice areas proposed in this application has achieved the following beneficial effects: First, by setting up a jettisonable buoyancy component and its first release mechanism, this application allows for the jettisoning of some buoyancy material as needed during the AUV's approach to the ice bottom or search for ice wells, thereby reducing positive buoyancy, improving the controllability of navigation near the ice bottom, and significantly reducing the control difficulty and power consumption when seeking position near the ice bottom.

[0088] Second, this application includes an emergency position indication beacon and its second release mechanism, with the beacon having its own independent power supply. When the AUV is trapped on the ice or experiences communication or power supply abnormalities, it can still be actively released and continuously transmit position indication information; combined with the mother ship's ultra-short baseline positioning system, it can achieve relatively accurate and rapid acquisition of the AUV's position, providing support for subsequent guidance and descent.

[0089] Third, this application configures the three types of actuators according to their functions: the buoyancy component release mechanism uses a de-energized electromagnet (magnetic when de-energized, demagnetized when energized) to prevent uncontrolled sinking caused by the accidental jettisoning of buoyancy components when the AUV loses power; the emergency beacon release mechanism and the surfacing and submerging ballast release mechanism use an excitation electromagnet (magnetic when energized, demagnetized when de-energized) to automatically release the beacon and ballast in the event of a power failure. The three mechanisms form a complementary safety logic under different operating conditions, ensuring the overall reliability of the positioning, surfacing, and descent processes.

[0090] In summary, this application optimizes the buoyancy state and handles anomalies of the AUV during the diving, operation, and navigation and recovery phases by adapting the release operation to the operation phase and setting differentiated electromagnet drive logic for different release mechanisms. It balances control accuracy during normal operation with safety redundancy under abnormal conditions, effectively ensuring the safety and reliability of the entire AUV operation process. It is particularly suitable for AUV operations in complex environments such as polar ice areas.

[0091] Based on the aforementioned methods for ensuring the safety of unmanned, untethered submersible navigation and recovery in polar ice areas, this application also provides an unmanned, untethered submersible comprising: Hull; The first release mechanism, installed on the hull, is used to release the jettisonable buoyancy component. The first release mechanism is driven by a de-energized electromagnet, which is magnetic when de-energized and demagnetized when energized. The first release mechanism is installed above the center of gravity of the boat and is equipped with a V-shaped guide groove to guide the jettisonable buoyancy component to avoid interference with the hull when it detaches. The second release mechanism, installed on the hull, is used to release the emergency position signal beacon. The second release mechanism is driven by an excitation electromagnet, which is magnetic when energized and demagnetized when de-energized. The second release mechanism is embedded in the bottom of the hull, and the emergency position signal beacon is connected to the hull via a connecting cable. The end of the connecting cable is equipped with an anti-detachment limit. The third release mechanism, installed on the hull, is used to release submerged ballast and / or surfaced ballast; the third release mechanism is driven by an excitation electromagnet, which is magnetic when energized and demagnetized when de-energized; The main control unit, installed on the hull, is electrically connected to the first release mechanism, the second release mechanism, and the third release mechanism, and is used to execute the safety assurance method for unmanned untethered submersible navigation and recovery in polar ice areas as described in this application.

[0092] In one embodiment of this application, the unmanned, untethered submersible is also equipped with a water leakage sensor, a depth gauge, an altimeter, an ice bottom rangefinder, and a mission timer.

[0093] It should be noted that the description of the unmanned untethered submersible in this application is similar to the description of the method embodiments described above, and has similar beneficial effects as the method embodiments; therefore, it will not be repeated. For any technical details not covered in the unmanned untethered submersible provided in this application, including its structure and operating procedures, please refer to... Figures 1 to 8 The meaning is understood in accordance with the description of any of the accompanying drawings.

[0094] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.

[0095] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0096] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for ensuring the safety of unmanned, untethered submersible navigation and recovery in polar ice areas, characterized in that, The method includes: Receive a work instruction, which includes a work execution phase; the work execution phase includes a diving phase, a work phase, and a navigation and recovery phase. In response to the operation instructions, the system performs operations in the polar ice zone based on data from its onboard sensors and the operation execution phase. During the operation, in response to the detection of an operation execution abnormality, a release operation corresponding to the operation execution stage is performed; the release operation includes at least one of the following: releasing a jettisonable buoyancy component through a first release mechanism, releasing an emergency position indication beacon through a second release mechanism, and releasing submerged ballast and / or floating ballast through a third release mechanism. The first release mechanism is driven by a de-energized electromagnet, which is magnetic when de-energized and de-energized when energized; the second release mechanism and the third release mechanism are driven by an excitation electromagnet, which are magnetic when energized and de-energized when de-energized.

2. The method according to claim 1, characterized in that, The sensor includes at least one of the following: a water leakage sensor, a depth gauge, an altimeter, an ice bottom rangefinder, and a task timer.

3. The method according to claim 2, characterized in that, When the operation execution phase is the diving phase, the operation based on data from its onboard sensors and the operation execution phase in the polar ice area includes: In polar ice regions, it relies on its own gravity to dive without power, and monitors the diving depth and the height from the bottom using the depth gauge and the altimeter. When the height above the bottom reaches a first set height threshold or the diving depth reaches the limit depth, the diving ballast is released by the third release mechanism; the limit depth is determined based on the maximum water depth in the operating area, and the limit depth is not greater than the design diving depth of the unmanned untethered submersible. In response to the completion of the ballast release during the submersion, the power system is activated to power the submersion to the set operating depth, thus entering the operating phase.

4. The method according to claim 3, characterized in that, The step of performing a release operation corresponding to the job execution phase in response to detecting a job execution anomaly includes: During unpowered descent, in response to the detection of any of the following conditions, the third release mechanism simultaneously releases the descent ballast and the surfacing ballast: The water leakage sensor in any pressure chamber of the unmanned, untethered submersible continuously detects water leakage for a first set time. The vertical velocity exceeded the theoretical maximum diving speed value for a consecutive second set time period. The vertical velocity was determined based on the depth collected at different times in the preceding sequence.

5. The method according to claim 4, characterized in that, The step of performing a release operation corresponding to the job execution phase in response to detecting a job execution abnormality further includes: After performing the release of submerged ballast, in response to detecting any of the following conditions, the submerged ballast and the floating ballast are released via the third release mechanism: The height from the bottom is less than or equal to the second set height threshold, and the rate of change of the vertical velocity compared with the velocity before the second set time does not exceed the first velocity change threshold. Within a second consecutive set time period, the difference between the depth gauge smoothing filter depth and the limit depth at different sampling times is greater than the first set depth change threshold.

6. The method according to claim 2, characterized in that, When the job execution phase is the job phase, the step of performing a release operation corresponding to the job execution phase in response to detecting a job execution abnormality includes: In response to detecting any of the following conditions, the floating ballast is released via the third release mechanism: The leak sensor in any pressure chamber of the unmanned, untethered submersible continuously detects a leak for a first set time. The task timer has reached its maximum time limit; The depth change is less than the first depth change threshold, and the height from the bottom measured by the altimeter gradually decreases and remains in an invalid state for a third consecutive set period of time; Within a consecutive second set time period, the difference between the smoothed filtering depth of the depth gauge and the designed depth at different sampling times is greater than the second set depth change threshold.

7. The method according to claim 2, characterized in that, When the operation execution phase is the navigation and recovery phase, the operation based on data from its onboard sensors and the operation in the polar ice zone during the operation execution phase includes: In polar ice regions, the buoyancy ballast is released through the third release mechanism, and the heading and horizontal position are adjusted according to the position information fed back by the mother ship's Ultra-Short Baseline Positioning System (USBL) to perform unpowered buoyancy. When the ice rises to a depth within the first set threshold without power, and the distance to the ice bottom measured by the ice bottom rangefinder is less than the third set height threshold for a continuous second set time period, the throwable buoyancy component is released through the first release mechanism. After releasing the jettisonable buoyancy component, the power system is activated to navigate using a powered ascent method to find the recovery point; By using the slant distance, bearing, and elevation angle measured by the mother ship's USBL based on the ship's coordinate system, the position coordinates relative to the mother ship are obtained every fourth set time interval. Based on the position coordinates, the ship is guided to move towards the recovery point until it enters the effective opening and closing angle range of the mother ship's USBL.

8. The method according to claim 7, characterized in that, The step of performing a release operation corresponding to the job execution phase in response to detecting a job execution anomaly includes: In response to any of the following conditions, the emergency position beacon is released downwards to a third preset depth threshold via the second release mechanism, so that the emergency position beacon enters the effective opening and closing angle range of the mother ship USBL, allowing the mother ship USBL to receive the signal transmitted by the emergency position beacon to calculate the submersible's position, and to approach and recover the unmanned, untethered submersible based on the calculated submersible's position: After the buoyancy component is released, the ice bottom rangefinder measures that the height above the ice surface is less than the first set height threshold, and the rate of change of the current vertical velocity compared with the velocity before the second set time does not exceed the first velocity change threshold. During navigation, the depth change is less than the third set depth difference threshold within a second consecutive set time period, and the change in distance from the ice bottom measured by the ice bottom rangefinder is less than the first set distance change threshold within a second consecutive set time period. During navigation, the position opening angle of the unmanned untethered submersible is greater than half of the effective opening angle of the mother ship USBL. The position opening angle is determined based on the height and slant distance of the unmanned untethered submersible. A complete power failure was detected.

9. The method according to claim 1, characterized in that, The emergency position signal beacon has an independent power supply.

10. An unmanned, untethered submersible, characterized in that: include: Hull; The first release mechanism, installed on the hull, is used to release the jettisonable buoyancy component. The first release mechanism is driven by a de-energized electromagnet, which is magnetic when de-energized and demagnetized when energized. The first release mechanism is installed above the center of gravity of the hull and is provided with a V-shaped guide groove to guide the jettisonable buoyancy component to avoid interference with the hull when it detaches. The second release mechanism, installed on the hull, is used to release the emergency position indicator beacon. The second release mechanism is driven by an excitation electromagnet, which is magnetic when energized and demagnetized when de-energized. The second release mechanism is embedded in the bottom of the hull, and the emergency position indicator beacon is connected to the hull via a connecting cable, the end of which is equipped with an anti-detachment limit. The third release mechanism, installed on the hull, is used to release submerged ballast and / or surfaced ballast; the third release mechanism is driven by an excitation electromagnet, which is magnetic when energized and demagnetized when de-energized; The main control unit, installed on the hull, is electrically connected to the first release mechanism, the second release mechanism, and the third release mechanism, and is used to execute the method for ensuring the safety of unmanned untethered submersible navigation and recovery in polar ice areas as described in any one of claims 1-9.

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