Seabed-based self-adapting levelling device and method based on shape memory alloys

Abstract

The present application relates to seabed base adjustment platform technical field, disclose a kind of seabed base self-adapting leveling device and method based on shape memory alloy, comprising: seabed base observation platform, for carrying instrument equipment;Leveling leg, evenly distributed in seabed base observation platform below, for using the shape memory effect and superelasticity of SMA, realize seabed base observation platform after bottom touch shock isolation and damping and full-automatic and high-reliability leveling;Gimbal connecting mechanism, for connecting leveling leg and foot pad, to adapt and support on different angle slope.Utilize the shape memory effect and superelasticity of SMA, without external power supply and complex control system, realize full-automatic, high-reliability leveling after platform bottom touch, to solve the technical problems that existing leveling scheme has different degrees of limitations in structural complexity, environmental adaptability, long-term reliability and leveling precision.

Description

Technical Field

[0001] This invention relates to the field of seabed-based adjustment platform technology, and in particular, to a seabed-based adaptive leveling device and method based on shape memory alloy. Background Technology

[0002] Seabed-based observation platforms are key equipment for long-term, fixed-point marine environmental observation. They typically house sophisticated instruments such as acoustic Doppler current profilers (ADCPs) and sediment traps. During deployment, due to the unpredictable nature of seabed topography, the landing point may be located on a slope or in an uneven area. If the platform lands on an inclined surface, the measurement reference points of its instruments will shift, severely impacting the accuracy and validity of the observation data.

[0003] Currently, the main methods for achieving leveling of seabed-based observation platforms include the following: Manual pre-leveling: This involves manually adjusting the extension length of the outriggers based on a prior estimate of the seabed topography at the pre-deployed site. This method is not only inefficient, but also has limited applicability due to the complexity, variability, and uncertainty of the actual seabed topography, making it difficult to guarantee the platform's levelness after it sits on the seabed.

[0004] Electric or hydraulic leveling: This method adjusts the outrigger length using built-in motors or hydraulic cylinders as active drive components. While it achieves a degree of automatic leveling, its system structure is typically complex, resulting in high manufacturing and maintenance costs, as well as significant energy consumption. More importantly, in harsh environments such as deep-sea high pressure and corrosion, the dynamic sealing reliability of the drive mechanism faces challenges, posing a potential threat to the long-term stability and reliability of observation platforms requiring continuous operation.

[0005] Passive buoy leveling: Based on the principle of buoyancy, buoys are installed on the upper part of the platform, and the overall center of gravity is lowered through structural design. The platform automatically tends to be upright in the water due to the combined effect of buoyancy and gravity. However, this passive leveling method has limited adjustment capability and effectiveness, and lacks stability on complex and uneven seabed topography. Especially when the platform's outriggers sink into soft mud, the bottom friction significantly counteracts the righting torque generated by the buoys, causing the leveling function to fail or be ineffective. For instruments like ADCPs, which have extremely high requirements for platform levelness and stability, even the slightest tilt or sway can introduce significant measurement errors. Summary of the Invention

[0006] This invention provides a seabed-based adaptive leveling device and method based on shape memory alloys (SMAs). Utilizing the shape memory effect and superelasticity of SMAs, it achieves fully automatic and highly reliable leveling of the platform after it touches the seabed without the need for an external power source or complex control system. This addresses the technical problem that existing leveling schemes have limitations in terms of structural complexity, environmental adaptability, long-term reliability, and leveling accuracy, making it difficult to meet the practical needs of seabed-based observation platforms to achieve high-precision and high-reliability automatic leveling under complex seabed topography.

[0007] According to one aspect of the present invention, a seabed-based adaptive leveling device based on shape memory alloy is provided, comprising: a seabed-based observation platform for supporting instruments and equipment; leveling legs evenly distributed below the seabed-based observation platform for utilizing the shape memory effect and superelasticity of SMA to achieve vibration isolation and damping after the seabed-based observation platform touches the bottom, as well as fully automatic and highly reliable leveling; and a universal joint connection mechanism for connecting the leveling legs to foot pads to adapt to and support slopes at different angles.

[0008] Furthermore, the leveling outriggers are arranged in at least three sets, and each set of leveling outriggers integrates an SMA actuator.

[0009] Furthermore, the SMA actuator includes an SMA spring, a bias spring, a locking / releasing mechanism, a pressure sensor, and a heating circuit. Both the SMA spring and the bias spring are arranged along the axial direction of the leveling leg, and are spaced parallel to each other. The pressure sensor is located on the SMA spring and is electrically connected to the heating circuit, which in turn is connected to the SMA spring. When the seabed-based observation platform touches the bottom via the footpad, the compressive stress on the relatively heavily stressed leveling leg causes a stress-induced martensitic phase transformation in the SMA spring. It also overcomes the elastic force of the bias spring to shorten, thereby releasing the compressive stress. For the leveling outrigger that is suspended or under relatively small force, the pressure sensor transmits the pressure signal of the leveling outrigger that is suspended or under relatively small force to the heating circuit. The heating circuit applies a short pulse current to the SMA spring of the corresponding leveling outrigger and heats the SMA spring. Due to the shape memory effect, the SMA spring pushes the leveling outrigger to extend until the foot pad contacts the seabed and obtains support force. The locking / releasing mechanism is used to mechanically lock the current state after the adaptive leveling is completed to avoid continuous energy consumption.

[0010] Furthermore, the SMA actuator also includes an SMA element housing and a piston; the SMA element housing is a cylindrical structure with one end open, the piston is slidably arranged inside the SMA element housing, the piston rod extends outward through the open end of the SMA element housing, and the SMA spring and bias spring are both arranged between the end plate of the SMA element housing and the piston.

[0011] Furthermore, the locking / releasing mechanism adopts a normally closed electromagnetic braking structure, which is used to mechanically lock the current state after the adaptive leveling is completed by utilizing the power-off locking characteristic to avoid continuous energy consumption.

[0012] Furthermore, the normally closed electromagnetic braking structure is located at the open end of the SMA element housing and is sealed and fixed by a sealing ring.

[0013] Furthermore, temperature sensors are also installed on the SMA spring.

[0014] Furthermore, a waterproof connector is provided outside the closed end of the SMA component housing.

[0015] Furthermore, the SMA spring, as the driving element, is made of SMA material, which is easily deformed at low temperatures and recovers its initial shape at high temperatures. The phase transition temperature is set in a range that is higher than the ambient seawater temperature but lower than the safe damage temperature.

[0016] Furthermore, the seabed-based observation platform is equipped with a power source (battery) to supply power to the leveling outriggers.

[0017] Furthermore, the power source (battery) supplies power to the pressure sensor, heating circuit, and temperature sensor.

[0018] According to another aspect of the present invention, a seabed-based adaptive leveling method based on shape memory alloys is also provided. Employing the aforementioned seabed-based adaptive leveling device based on shape memory alloys, the method includes the following steps: S100, the seabed-based adaptive leveling device carrying instruments is deployed in seawater and sunk to the seabed, causing the seabed-based observation platform of the adaptive leveling device to tilt due to the seabed topography; S200, among the leveling legs in the tilted state, the leveling leg supported at the higher point experiences relatively greater force, and the SMA actuator of the leveling leg is subjected to compressive stress; while the leveling legs that are suspended or experience relatively less force have their SMA actuators in a relaxed or low-stress state; S300, for the leveling legs experiencing relatively greater force, the compressive stress causes stress-induced martensitic phase transformation and shortening of the SMA actuators on the leveling leg, thereby allowing the leveling leg to yield and contract, and Stress relief; For the leveling outriggers that are suspended or under relatively little stress, the pressure sensor transmits a signal to the heating circuit. The heating circuit applies a short-time pulse current to the SMA actuator of the corresponding leveling outrigger, heating the SMA spring. Due to the shape memory effect, the SMA spring returns to its initial shape, pushing the internal piston to move radially outward, extending the leveling outrigger until the foot pad at the bottom of the leveling outrigger contacts the seabed and obtains support; S400, the seabed-based observation platform gradually adjusts to a horizontal state through a high contraction and low elongation adaptive adjustment process; when all leveling outriggers are in contact with the seabed and the force is balanced, the leveling ends, the normally closed electromagnetic brake is de-energized, and the length of all leveling outriggers is locked, completing the adjustment process; S500, after the seabed-based observation platform completes the leveling process, the main control system is activated, and the instruments and equipment begin to work according to the preset program.

[0019] The present invention has the following beneficial effects: 1. Fully automatic, passive adaptive leveling is achieved: The leveling process is driven by the inherent properties of shape memory alloy (SMA). When the seabed-based observation platform touches the bottom and the leveling outriggers are subjected to uneven forces, the SMA elements under pressure will undergo superelastic deformation due to stress-induced martensitic phase transformation, effectively absorbing impact energy and playing a role in vibration isolation and damping. At the same time, under the influence of seawater temperature (or SMA phase transformation temperature), the SMA elements tend to recover to the pre-set memory shape due to their shape memory effect, thereby actively adjusting the support state of the outriggers. This process is completed entirely by the interaction between the physical properties of the material itself and the external environment, without relying on external power, hydraulic power sources or complex sensor control systems, thus achieving truly automatic and passive adaptive leveling.

[0020] 2. Improved reliability and environmental adaptability of the leveling process: Since the leveling action is based on the solid-state phase change of SMA material, it eliminates the need for complex mechanical systems containing moving parts and dynamic seals, such as traditional motors and hydraulic cylinders. This fundamentally avoids the risk of failure due to mechanical wear and seal failure. This simple solid-state drive method enhances the reliability of the device in long-term operation in the high-pressure and highly corrosive environment of the deep sea. The leveling legs are connected to the foot pads through the universal joint connection mechanism, ensuring that the foot pads can always conform to the sloping seabed surface at different angles. This provides a stable foundation for the effective operation of the SMA components of the leveling legs, enabling the device to adapt to various complex and uneven seabed topography.

[0021] 3. Optimized leveling accuracy and platform stability: During the process of hyperelastic deformation and shape recovery, SMA material can provide smooth and controllable force-displacement characteristics, making the leveling process not a simple rigid positioning, but with a certain degree of flexibility. This allows it to better adapt to local changes in seabed geology and geomorphology, achieving more precise pressure balance and attitude adjustment. Ultimately, through the coordinated action of multiple leveling legs, the seabed-based observation platform achieves a stable and precise horizontal state, providing an ideal measurement benchmark for the precision instruments such as ADCP that have extremely high requirements for platform stability, fundamentally ensuring the accuracy of observation data.

[0022] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of a seabed-based adaptive leveling device based on shape memory alloy according to a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the SMA execution unit according to a preferred embodiment of the present invention.

[0024] Legend: 100. Seabed-based observation platform; 200. Leveling outriggers; 300. Universal joint connection mechanism; 400. Foot pads; 500. SMA actuator; 501. SMA spring; 502. Offset spring; 503. Locking / releasing mechanism; 504. SMA component housing; 505. Piston; 5051. Rod; 506. Sealing ring; 507. Waterproof connector; 508. Heating element; 600. Pressure sensor; 700. Tilt sensor; 800. Temperature sensor. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0026] like Figure 1 and Figure 2As shown, the seabed-based adaptive leveling device based on shape memory alloy in this embodiment includes: a seabed-based observation platform 100 for carrying instruments and equipment; leveling legs 200, evenly distributed below the seabed-based observation platform 100, used to utilize the shape memory effect and superelasticity of SMA to achieve vibration isolation and damping after the seabed-based observation platform 100 touches the bottom, as well as fully automatic and highly reliable leveling; and a universal joint connecting mechanism 300 for connecting the leveling legs 200 to the foot pads 400 to adapt to and support slopes at different angles. This invention relates to a seabed-based adaptive leveling device based on shape memory alloys (SMAs). The device utilizes the inherent properties of SMAs to drive the leveling process. When the seabed-based observation platform 100 touches the bottom and the leveling legs 200 experience uneven stress, the SMA elements under pressure undergo stress-induced martensitic phase transformation, resulting in hyperelastic deformation. This effectively absorbs impact energy and provides vibration isolation and damping. Simultaneously, under the influence of seawater temperature (or SMA phase transformation temperature), the SMA elements, due to their shape memory effect, tend to recover to a pre-set memory shape, thereby actively adjusting the support state of the legs. This process is entirely accomplished by the interaction between the material's inherent physical properties and the external environment, without relying on external power, hydraulic power sources, or complex sensor control systems, achieving truly fully automatic and passive adaptive leveling. Since the leveling mechanism is based on the solid-state phase change of SMA material, it eliminates the need for complex mechanical systems containing moving parts and dynamic seals, such as traditional motors and hydraulic cylinders. This fundamentally avoids the risk of failure due to mechanical wear and seal failure. This simple solid-state drive method enhances the reliability of the device in long-term operation in the high-pressure and highly corrosive environment of the deep sea. The leveling leg 200 is connected to the foot pad 400 through the universal joint connection mechanism 300, ensuring that the foot pad 400 can always conform to the sloping seabed surface at different angles. This provides a stable foundation for the effective operation of the SMA element of the leveling leg 200, enabling the device to adapt to various complex and uneven seabed topography. During the process of superelastic deformation and shape recovery, SMA material can provide smooth and controllable force-displacement characteristics, making the leveling process not a simple rigid positioning, but with a certain degree of flexibility. This allows it to better adapt to local changes in seabed geology and geomorphology, achieving more precise pressure balance and attitude adjustment. Ultimately, through the coordinated action of multiple leveling legs 200, the seabed-based observation platform 100 reaches a stable and precise horizontal state, providing an ideal measurement benchmark for the precision instruments such as ADCP that have extremely high requirements for platform stability, fundamentally ensuring the accuracy of the observation data.This invention relates to a seabed-based adaptive leveling device based on shape memory alloys (SMA). By combining the intelligent material properties of SMA with mechanical structures (such as universal joint connections), it successfully provides a simple, reliable, and adaptable automatic leveling solution that can adapt to complex seabed topography without requiring external power. This overcomes many shortcomings of existing technologies, such as low efficiency, poor reliability, and insufficient adaptability, which rely on manual prediction, complex electro-hydraulic actuation, or passive buoyancy leveling. It is particularly suitable for seabed-based observation platforms 100 that need to operate autonomously for extended periods in harsh marine environments, providing technical support for achieving their high-precision scientific observation tasks. Optionally, the seabed-based observation platform 100 is equipped with an tilt sensor 700.

[0027] like Figure 1 and Figure 2 As shown, in this embodiment, at least three sets of leveling legs 200 are arranged, and each set of leveling legs 200 integrates an SMA actuator 500. By setting at least three sets of leveling legs, a stable statically determinate support system is formed. Each set of legs integrates an SMA actuator, enabling each support point of the seabed-based adaptive leveling device in contact with the seabed to have independent and active adjustment capabilities. This ensures that regardless of the platform's posture or the complexity of the terrain it contacts, its leveling action can cover the entire support surface, avoiding the problems caused by insufficient support points or lack of active adjustment capabilities. Optionally, at least four sets of leveling legs 200 are arranged; the support of four or more points forms a statically indeterminate structure, which can effectively suppress the small rotations or swaying that may occur around any axis after the platform is seated. Especially when dealing with uneven seabed sediment, ocean current impacts, or micro-vibrations caused by the operation of internal equipment, it can provide stronger constraints, thereby providing a more stable measurement benchmark for the precision observation instruments (such as ADCP) mounted on the platform.

[0028] like Figure 1 and Figure 2As shown, in this embodiment, the SMA execution unit 500 includes an SMA spring 501, a bias spring 502, a locking / releasing mechanism 503, a pressure sensor 600, and a heating circuit. The SMA spring 501 and bias spring 502 are both arranged along the axial direction of the leveling leg 200, and are arranged parallel to each other at intervals. The pressure sensor 600 is located on the SMA spring 501 and is electrically connected to the heating circuit, which is connected to the SMA spring 501. When the seabed-based observation platform 100 touches the bottom via the footpad 400, the compressive stress on the relatively large leveling leg 200 causes the SMA spring on the leveling leg 200 to... Stress-induced martensitic phase transformation occurs at 501, which overcomes the elastic force of bias spring 502 and shortens, thereby releasing compressive stress. For the suspended or relatively low-stressed leveling leg 200, the pressure sensor 600 transmits the pressure signal of the suspended or relatively low-stressed leveling leg 200 to the heating circuit. The heating circuit applies a short-time pulse current to the SMA spring 501 of the corresponding leveling leg 200 and heats the SMA spring 501. Due to the shape memory effect, the SMA spring 501 pushes the leveling leg 200 to extend until the foot pad 400 contacts the seabed and obtains support force. The locking / releasing mechanism 503 is used to mechanically lock the current state after adaptive leveling is completed to avoid continuous energy consumption. The SMA actuator 500 integrates the physical characteristics of the pressure sensor 600 and the SMA spring 501 to form an intelligent system with sensing and response capabilities. For the leveling outrigger 200, which experiences significant force after bottoming out, the SMA spring 501 passively shortens due to a phase change using the hyperelastic effect, actively releasing pressure and providing cushioning and initial adaptation to the terrain. For outriggers that are suspended or experience less force, the pressure sensor 600 senses the state and actively triggers the heating circuit, causing the SMA spring 501 to actively extend using the shape memory effect to seek support. This mechanism, which combines passive shortening and pressure relief with active extension for support, enables coordinated self-adaptation among the leveling outriggers 200, allowing them to autonomously complete the leveling process without the need for complex calculations by a central controller. By concentrating energy consumption on the critical stages of the leveling process, a short-time pulse current is applied to a specific SMA spring 501 only when the outriggers need to be actively extended. Once all foot pads 400 are in contact with the seabed and the platform reaches a level state through the combined adjustment of active extension and passive shortening, the locking / releasing mechanism 503 mechanically locks the current state. This avoids the energy consumption required to continuously power on the SMA spring 501 to maintain its phase change state (i.e., maintain the outrigger length) during long-term observation. This makes the leveling device of the present invention particularly suitable for observation platforms that require long-term seabed monitoring and have difficult energy replenishment, achieving a balance between high-efficiency leveling and extremely low static power consumption.The parallel SMA springs 501 and 502 form an inherent force balance system. The 502 not only provides a counterforce for the shortening or resetting of the SMA spring 501, but also ensures the smoothness and controllability of the extension and retraction of the leveling leg 200. The locking / releasing mechanism 503 rigidly fixes the leveling leg 200 after leveling, effectively preventing minor deformations that may occur due to reverse phase transitions of the SMA material under ambient temperature fluctuations or external disturbances such as ocean currents. This ensures the platform maintains extremely high attitude stability throughout the entire observation period, providing reliable assurance for precision measurements. Optionally, the heating element 508 of the heating circuit is located at at least one end of the SMA spring 501.

[0029] like Figure 2As shown, in this embodiment, the SMA execution unit 500 further includes an SMA element housing 504 and a piston 505; the SMA element housing 504 is a cylindrical structure with one end open, the piston 505 is slidably arranged inside the SMA element housing 504, the rod 5051 of the piston 505 extends outward through the open end of the SMA element housing 504, and the SMA spring 501 and the bias spring 502 are both arranged between the end plate of the SMA element housing 504 and the piston 505. The SMA element housing 504 and piston 505 together form a compact actuator module, providing a closed housing space for the SMA spring 501 and bias spring 502, effectively protecting these core functional components from external mechanical impacts, seawater, marine organism attachment, or silt intrusion. The sliding fit between the cylindrical housing and piston 505 provides precise linear guidance for the extension and retraction of the rod 5051 (piston rod), ensuring that the extension and retraction of the leveling leg 200 always proceed along the predetermined axial direction, avoiding jamming, wear, or energy loss caused by lateral forces or non-axial movements, thereby ensuring the reliability and accuracy of the actuation process. The SMA spring 501 and the bias spring 502 are arranged in parallel between the end plate of the housing and the piston 505, forming an efficient force transmission path. Whether it is the force generated by the active contraction of the SMA spring 501, the reaction force provided by the bias spring 502, or the external pressure, it is directly transmitted to the piston 505 through this compact structure and converted into the axial output of the rod 5051 (piston rod). This parallel arrangement makes full use of the radial space of the housing, making the SMA actuator 500 more compact in axial dimensions, which is beneficial to the structural design of the entire leveling leg 200 and realizes the large stroke actuation requirement in a small space. By integrating core components such as SMA spring 501 and bias spring 502 into a separate SMA component housing 504, a fully functional, pre-assembled, and testable modular SMA actuator unit 500 is formed. This modular design facilitates installation, replacement, and maintenance. If an SMA actuator unit 500 needs maintenance, it can be easily removed from the leveling leg 200 without disassembling other parts of the leveling leg 200, which significantly improves the maintainability of the device.

[0030] like Figure 1As shown, in this embodiment, the locking / releasing mechanism 503 adopts a normally closed electromagnetic braking structure. After adaptive leveling is completed, it uses the power-off locking characteristic to mechanically lock the current state, avoiding continuous energy consumption. The locking / releasing mechanism 503 is in a mechanically locked state when not energized. During the leveling process, the braking can be released by briefly energizing the electromagnet when adjustment is needed. Once leveling is completed, the electromagnet is de-energized and automatically returns to and remains locked under the action of spring force, etc. This "energy-consuming during operation and self-locking when stationary" working mode means that in long-term seabed observation missions, only the initial leveling phase consumes electrical energy, while the lock is in a zero-power-consumption locking state for most of the monitoring time. This solves the energy consumption bottleneck caused by the need for continuous power supply to maintain attitude in traditional active leveling schemes, and is particularly suitable for seabed-based platforms with limited energy. The normally closed design of the locking / releasing mechanism 503 follows the fail-safe principle. In extreme cases, such as unexpected power failure of the control system or circuit failure, the mechanism will automatically enter and remain in a locked state instead of being released uncontrollably. This prevents the risk of platform instability due to power loss, provides important safety redundancy for the entire observation system, and greatly improves the long-term operational reliability of the device in unattended environments. The locking / releasing mechanism 503 directly locks the rod 5051 (piston rod) or other transmission components mechanically (such as the pressing of friction plates or the engagement of pawls). Its locking force does not depend on continuous power input but is provided by the mechanical structure itself. It can effectively resist environmental interference such as ocean current impact and equipment vibration, and prevent the SMA spring 501 from undergoing slight reverse deformation due to material creep or ambient temperature fluctuations. This ensures the high stability of the platform's horizontal attitude after leveling throughout the entire observation period, providing a reliable measurement basis for precision instruments.

[0031] like Figure 1 and Figure 2As shown, in this embodiment, the normally closed electromagnetic braking structure is disposed at the open end of the SMA element housing 504 and sealed and fixed by the sealing ring 506. By placing the normally closed electromagnetic braking structure at the open end of the SMA element housing 504, i.e., the protruding part of the rod 5051 (piston rod), it can directly act on the final output component of the actuator. This allows the normally closed electromagnetic braking structure to most directly and effectively restrict the axial movement of the rod 5051 (piston rod), thereby locking the length of the leveling support leg 200 at its source. Directly acting on the motion output end avoids potential gaps or elastic deformations that may exist when locking through the transmission chain, ensuring the immediacy of the locking action and the absolute reliability of the locked state. The normally closed electromagnetic braking structure is sealed and fixed to the SMA component housing 504 by the sealing ring 506. This allows the SMA spring 501, the bias spring 502, and the normally closed electromagnetic braking structure itself to be encapsulated in a unified sealed cavity, effectively isolating them from the intrusion of high-pressure seawater, silt, and corrosive ions. This provides comprehensive protection for these core functional components containing precision mechanical and electromagnetic elements, ensuring their reliability and durability during long-term operation in harsh deep-sea environments. Integrating the normally closed electromagnetic braking structure into the end of the SMA component housing 504 forms a compact and functionally integrated modular actuator. This tightly integrates power output (piston rod), intelligent material drive (SMA spring 501), and state locking (normally closed electromagnetic braking structure), simplifying the overall mechanical transmission chain of the leveling outrigger 200, reducing intermediate links, and improving structural rigidity and response speed. At the same time, this integrated module also facilitates overall testing, installation, and maintenance.

[0032] like Figure 2 As shown, in this embodiment, a temperature sensor 800 is also installed on the SMA spring 501. The temperature sensor 800 is electrically connected to the heating circuit. The phase transformation (transformation between martensite and austenite) of the shape memory alloy has a definite correlation with temperature. By directly monitoring the real-time temperature of the SMA spring 501 body through the temperature sensor 800, a precise feedback signal can be provided for the start and stop of the heating circuit. For example, when the SMA spring 501 is heated by a pulse current to extend it, the temperature sensor 800 can monitor its temperature rise in real time. When the temperature reaches the temperature at which the austenite phase transformation is completed, the current can be cut off to avoid overheating. This achieves precise closed-loop temperature control of the SMA driving process, preventing material performance degradation or energy waste caused by overheating, and also avoiding incomplete operation caused by insufficient heating, thereby improving the accuracy and reliability of the leveling action. The readings from temperature sensor 800 serve as a crucial basis for determining the operating status of SMA actuator 500. If the temperature of SMA spring 501 rises abnormally without applied current, it may indicate abnormal ambient temperature or overheating due to malfunction in adjacent components. If the temperature response is abnormal after applying current, it may indicate problems such as poor contact in the heating circuit. Monitoring temperature data allows for a preliminary diagnosis of the actuator's status. Temperature sensor 800 also acts as a key component for overheat protection; once the temperature exceeds the safety threshold, it immediately cuts off the heating circuit, preventing damage to the SMA element due to overheating and enhancing system safety. Ambient temperatures vary at different water depths, affecting the initial state and phase transition dynamics of the SMA element. Real-time temperature data provided by temperature sensor 800 allows the control system to sense changes in ambient temperature and potentially fine-tune the parameters of the heating pulse (such as current magnitude and duration) to compensate for the impact of ambient temperature on the leveling action. This ensures the device maintains stable and consistent leveling performance in different sea areas and seasons, enhancing its environmental adaptability.

[0033] like Figure 2 As shown, in this embodiment, a waterproof connector 507 is provided on the closed end of the SMA element housing 504. The waterproof connector 507 provides a dedicated, standardized through-chamber interface for the cables connecting the heating circuit, pressure sensor 600, and temperature sensor 800, ensuring that electrical energy and control signals can be reliably transmitted from the external main control system or power supply to the SMA actuator 500 (including the SMA spring 501, heating circuit, temperature sensor 800, pressure sensor 600, etc.) inside the sealed housing. At the same time, it strictly prevents high-pressure seawater from seeping into the housing along the cable gaps, providing a prerequisite for the normal operation of the entire intelligent drive unit and serving as a fundamental guarantee for realizing its electrical control functions. The cable entry point is one of the weakest links in the sealed housing. Without a dedicated waterproof connector 507, directly sealing the cable would compromise its reliability under long-term high-pressure conditions in the deep sea. The dedicated waterproof connector 507, a mature industrial standard component, is specifically designed and verified to withstand the high pressure of the deep sea, providing a durable and reliable static seal for the cable entry point. This, together with the sealing components of other parts of the SMA component housing 504 (such as the sealing ring 506), forms a complete and reliable sealing system, ensuring the long-term safety of the internal core components. By using standardized waterproof connectors 507, the entire SMA actuator 500 can be manufactured and tested as an independent, pre-integrated functional module. During final assembly, electrical connections are simply established by connecting the external cables to the connector, simplifying the system integration process and facilitating installation and subsequent maintenance. Replacing an SMA actuator 500 can also be achieved by quickly disconnecting this connector, improving system maintainability.

[0034] In this embodiment, the SMA spring 501 serves as the driving element. It is made of SMA material, which is easily deformed at low temperatures and recovers its initial shape at high temperatures. The phase transition temperature is set within a range higher than the ambient seawater temperature but lower than the safe damage temperature. Setting the phase transition temperature of the SMA spring 501 within this range forms the thermodynamic basis for the device's operation. In the seabed environment, the SMA spring 501 is in a martensitic state due to its low temperature (ambient seawater temperature), making it relatively soft and easily deformable under external forces (i.e., possessing superelasticity). This provides a prerequisite for the outriggers to buffer and initially adapt to the terrain through stress-induced phase transitions when the platform touches the bottom. When active driving is required, its temperature is raised above the phase transition point through electric heating, and the SMA spring 501 reliably recovers its initial shape (austenitic state), generating driving force. This setting allows the driving logic of "easily deformed at low temperatures and recovering at high temperatures" to naturally match the marine environment temperature, making the environment a natural cold source. Setting the upper limit of the phase transformation temperature to a range far below the material's safe damage temperature provides a safe operating range for electric heating control. This avoids the risk of material annealing, performance degradation, or even failure due to overheating of the SMA spring 501 caused by control inaccuracies or unexpected situations during active heating. A clear and safe temperature window simplifies the design of the heating circuit's control strategy; simply controlling the temperature within this range ensures both effective and safe driving action, improving the overall robustness of the system. Since the phase transformation temperature is higher than the ambient seawater temperature, after active heating stops, the SMA spring 501 will naturally cool through heat exchange with the ambient seawater, eventually stabilizing at an ambient temperature below the phase transformation point. At this temperature, the SMA spring 501, in its martensitic state, is stable and has no inherent tendency to spontaneously transform into austenite. This means that once the seabed-based observation platform 100 is leveled and heating stops, the current length state of the SMA spring 501 will be determined by its own mechanical properties and external constraints, rather than spontaneously changing due to ambient temperature fluctuations. This ensures that the seabed-based observation platform 100 maintains attitude stability during long-term observation.

[0035] In this embodiment, the seabed-based observation platform 100 is equipped with a power source (e.g., a battery) to power the leveling outriggers 200. The power source is also the energy source for the heating circuit, locking / releasing mechanism 503 (when energized and released), sensors, and control circuits in the SMA execution unit 500. By integrating the power source (e.g., a high-energy-density battery pack) inside the seabed-based observation platform 100, the platform can independently complete the leveling task and maintain the operation of subsequent observation equipment throughout the entire observation cycle from deployment to retrieval without relying on submarine cables for power or requiring mid-journey energy replenishment. This allows the observation platform to be deployed in any sea area far from shore-based power supply facilities, greatly expanding its operational range and application scenarios, and facilitating the realization of an autonomous mobile observation platform. The power supply on the seabed-based observation platform 100 serves as a unified energy center, providing power not only to the leveling outriggers 200 but also to other observation instruments (such as ADCP) mounted on the platform. This centralized power supply mode facilitates the planning and management of the platform's total energy consumption. In particular, the design, combined with short-time pulse current and mechanical locking to avoid continuous energy consumption, allows limited electrical energy to be used precisely and efficiently in the critical stage of leveling, thereby maximizing the platform's continuous monitoring time on the seabed while ensuring core functions.

[0036] In this embodiment, the power supply provides power to the pressure sensor 600, the heating circuit, and the temperature sensor 800.

[0037] This embodiment of the seabed-based adaptive leveling method based on shape memory alloys utilizes the aforementioned seabed-based adaptive leveling device based on shape memory alloys, including the following steps: S100, the seabed-based adaptive leveling device carrying instruments and equipment is deployed in the seawater and sunk to the seabed, causing the seabed-based observation platform 100 of the seabed-based adaptive leveling device to tilt due to the seabed topography; S200, among the leveling legs 200 in the tilted state, the leveling leg 200 supported at the higher point experiences relatively greater force, and the SMA actuator 500 of the leveling leg 200 is subjected to compressive stress; while the leveling leg 200 that is suspended or subjected to relatively less force is in a relaxed or low-stress state; S300, for the leveling leg 200 subjected to relatively greater force, the compressive stress causes the SMA actuator 500 on the leveling leg 200 to undergo stress-induced martensitic phase transformation and shorten, thereby allowing the leveling leg 200 to yield and contract, and releasing stress; for the suspended... For the leveling leg 200 with relatively small force, the pressure sensor 600 transmits a signal from the suspended or relatively small force-bearing leg to the heating circuit. The heating circuit applies a short-time pulse current to the SMA actuator 500 of the corresponding leveling leg 200, heating the SMA spring 501. Due to the shape memory effect, the SMA spring 501 returns to its initial shape, pushing the internal piston 505 to move radially outward, extending the leveling leg 200 until the foot pad 400 at the bottom of the leveling leg 200 contacts the seabed and obtains support. S400, the seabed-based observation platform 100 gradually adjusts to a horizontal state through a high contraction and low elongation adaptive adjustment process. When all leveling legs 200 are in contact with the seabed and the force is balanced, the leveling ends, the normally closed electromagnetic brake is de-energized, and the length of all leveling legs 200 is locked, completing the adjustment process. S500, after the leveling process of the seabed-based observation platform 100 is completed, the main control system is awakened, and the instruments and equipment begin to work according to the preset program. Different leveling outriggers 200 autonomously and in parallel adopt different leveling strategies according to their actual stress state. Outriggers under heavy stress passively shorten due to the hyperelastic effect of SMA (short-terminal elasticity), while leveling outriggers 200 that are suspended or under light stress actively elongate using the shape memory effect of SMA through electrothermal excitation (active support seeking). This collaborative mechanism of "self-lowering at high points and self-raising at low points" eliminates the need for a complex central controller to calculate tilt angles and plan outrigger lengths. The system can spontaneously and intelligently drive the platform towards a horizontal state through the distributed response of material properties and simple electrical signals, achieving a high degree of automation and intelligence.The leveling process is rapid, starting immediately after the platform touches the seabed. The fast phase transition speed of the SMA material ensures the timeliness of the leveling action. Pressure sensors 600 detect the leg status, and short-time pulsed currents are used for precise heating control, giving the extension action a clear target until it contacts the seabed and gains support, avoiding unnecessary energy consumption. After leveling, the normally closed electromagnetic brake is de-energized and locked, and the entire system enters a zero-static-power maintenance state. By strictly concentrating energy consumption within the brief time of the leveling action, the system achieves precise leveling and long-term maintenance with minimal energy cost, making it extremely suitable for long-term seabed monitoring missions with limited energy. Finally, a mechanical locking mechanism fixes the length of all leveling legs 200, ensuring that the horizontal state of the seabed-based observation platform 100 no longer depends on any continuous energy supply or material phase maintenance. This fundamentally eliminates the risk of attitude changes due to power outages, component aging, or environmental temperature fluctuations, providing an extremely stable platform foundation for subsequent long-term precision observations. The method establishes a process where the main control system and instruments are only activated after leveling is complete. This ensures that the instruments only begin collecting data in their optimal working posture, avoiding the problem of collecting invalid data in tilted states and ensuring the validity and scientific rigor of the entire observation mission's data. This invention, based on a shape memory alloy-based seabed-based adaptive leveling method, achieves a leveling strategy highly compatible with the characteristics of the marine environment through a process of active-passive coordination, distributed driving, and final mechanical locking. It not only realizes fully automatic and intelligent leveling operations but also achieves an excellent balance between leveling speed, accuracy, energy efficiency, and long-term stability. This provides seabed-based scientific observation equipment with a reliable method to quickly establish and maintain a stable, horizontal working benchmark on complex and unknown seabed topography, thereby significantly improving the quality and reliability of long-term fixed-point marine environmental observation data.

[0038] In practice, a seabed-based adaptive leveling device and method based on shape memory alloy (SMA) is provided. This device utilizes the shape memory effect and superelasticity of SMA to achieve fully automatic and highly reliable leveling of the platform after it touches the seabed, without the need for an external power source or complex control system.

[0039] 1. Device components: The adaptive leveling device mainly includes: a seabed-based observation platform 100, leveling outriggers 200, a universal joint connection mechanism 300, and an SMA actuator 500.

[0040] Seabed-based observation platform 100: used to carry scientific instruments and energy systems.

[0041] Leveling outriggers 200: There are usually 4 outriggers, evenly distributed below the seabed-based observation platform 100.

[0042] Universal joint connecting mechanism 300: Connects foot pad 400 and leveling leg 200, allowing foot pad 400 to rotate flexibly with multiple degrees of freedom within a certain range to adapt to slopes of different angles. The end of universal joint connecting mechanism 300 is foot pad 400 to increase the contact area with the seabed and prevent sinking.

[0043] SMA Actuation Unit 500: This is the core of the invention. Each leveling leg 200 integrates an SMA Actuation Unit 500, which includes: SMA Spring 501: As a driving element. SMA material (such as NiTiNol alloy) that is easily deformable at low temperature (martensitic phase) and recovers its original shape at high temperature (austenitic phase) is selected. Its phase transformation temperature (Af point) is set in the range of higher than the ambient seawater temperature but lower than the safe damage temperature (e.g., between 5°C and 40°C).

[0044] Bias spring 502: Works with SMA spring 501 to provide a counterforce (ordinary stainless steel spring).

[0045] Locking / Release Mechanism 503: After the SMA completes the drive, the current state is mechanically locked by the power-off locking characteristic of the normally closed electromagnetic locking mechanism to avoid continuous energy consumption.

[0046] Heating circuit: A simple resistance heating circuit is used, in which a high-resistivity conductive film is deposited on the surface of the SMA spring 501 (e.g., a Nitino spring). When current passes through this coating, heat is generated according to Joule's law, and the heat is directly conducted to the internal SMA material, initiating a phase transition. Power is supplied by batteries from the seabed-based observation platform 100.

[0047] 2. Methodology Section: The adaptive leveling method includes the following steps: Step 1: Deployment and Bottom Contact. The seabed platform is deployed into the water and sinks to the seabed. Upon contact with the bottom, due to the uneven seabed topography, each leveling leg 200° experiences different supporting reaction forces, causing the platform to tilt.

[0048] Step Two: Stress Sensing and Triggering. In the tilted outriggers, those suspended or under less stress have SMA actuators 500 in a relaxed or low-stress state. However, the outriggers supported at higher points experience significant compressive stress on their leveling outriggers 200 and SMA actuators.

[0049] Step 3: Adaptive Driving: For the stressed outrigger: The huge compressive stress causes the SMA element on the outrigger to undergo stress-induced martensitic phase transformation and shorten, allowing the outrigger to "yield" and shrink, releasing stress to a certain extent.

[0050] For the outriggers: Pressure sensors transmit signals to the outriggers, and the control circuit applies a short-duration pulse current to the SMA elements of these outriggers, causing them to heat up. Due to the shape memory effect, the SMA elements contract, pulling the internal piston 505 upward. Since the platform's weight is much greater than that of the outrigger, the upward pulling force is converted into a downward thrust on the outrigger, causing it to extend downward until its footpad 400 contacts the seabed and gains support.

[0051] Step Four: Balancing and Locking. Through the above process of "high contraction, low extension," the platform is gradually adjusted to a level position. When all outriggers are in contact with the seabed and the forces are balanced, the leveling process is complete. The normally closed electromagnetic brakes are de-energized, locking the outrigger lengths, and the leveling process is finished.

[0052] Step 5: Enter observation mode. After the platform is leveled, the main control system is activated, and each scientific instrument begins long-term observation according to the preset program.

[0053] The main advantages of this invention are: Fully passive / semi-active, highly efficient and energy-saving: The core leveling process utilizes the material properties of SMA, eliminating the need for complex sensor arrays and continuously operating control algorithms. It only provides short-term power to the suspended outriggers when necessary, resulting in extremely low energy consumption.

[0054] High reliability: It eliminates the need for easily damaged motors, hydraulic cylinders and precision transmission components, has a simple structure and fewer sealing points, making it very suitable for long-term, harsh deep-sea environments.

[0055] Rapid response: The phase transition process of SMA is rapid, and the leveling process can be completed within minutes after the platform bottoms out.

[0056] High environmental adaptability: The universal joint design allows the outriggers to flexibly adapt to various complex terrains, greatly improving the success rate of deployment and data quality.

[0057] Matters not covered in this invention are common knowledge.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A seabed-based adaptive leveling device based on shape memory alloy, characterized in that, include: Seabed-based observation platform (100) is used to carry instruments and equipment; Leveling outriggers (200) are evenly distributed under the seabed-based observation platform (100) to utilize the shape memory effect and superelasticity of SMA to achieve seismic isolation and vibration reduction after the seabed-based observation platform (100) touches the bottom, as well as fully automatic and highly reliable leveling; Universal joint connection mechanism (300) is used to connect leveling outrigger (200) to foot pad (400) to adapt to and support slopes at different angles; Each leveling support leg (200) is equipped with an SMA actuator (500). The SMA actuator (500) includes an SMA spring (501), a bias spring (502), a locking / releasing mechanism (503), a pressure sensor, and a heating circuit; Both the SMA spring (501) and the bias spring (502) are arranged along the axial direction of the leveling leg (200), and the SMA spring (501) and the bias spring (502) are arranged in parallel at intervals. The pressure sensor is installed on the SMA spring (501), and the pressure sensor is electrically connected to the heating circuit. The heating circuit is connected to the SMA spring (501). When the seabed-based observation platform (100) touches the bottom via the footpad (400), for the leveling leg (200) which is under relatively greater stress, the compressive stress causes the SMA spring (501) on the leveling leg (200) to undergo stress-induced martensitic phase transformation and overcome the elastic force of the bias spring (502) to shorten, thereby releasing the compressive stress. For the leveling leg (200) which is suspended or under relatively less stress, the pressure signal of the leveling leg (200) which is suspended or under relatively less stress is transmitted to the heating circuit via the pressure sensor. The heating circuit applies a short-time pulse current to the SMA spring (501) of the corresponding leveling leg (200) and heats the SMA spring (501). Due to the shape memory effect, the SMA spring (501) pushes the leveling leg (200) to extend until the footpad (400) contacts the seabed and obtains support. The locking / releasing mechanism (503) is used to mechanically lock the current state after adaptive leveling is completed to avoid continuous energy consumption; The SMA spring (501) is used as the driving element. It is made of SMA material spring, which is easy to deform at low temperature and recovers its initial shape at high temperature. The phase change temperature is set in the range of higher than the ambient seawater temperature but lower than the safe damage temperature.

2. The seabed-based adaptive leveling device based on shape memory alloy according to claim 1, characterized in that, The leveling outriggers (200) are provided in at least three sets.

3. The seabed-based adaptive leveling device based on shape memory alloy according to claim 2, characterized in that, The SMA actuator (500) also includes an SMA element housing (504) and a piston (505); The SMA element housing (504) is a cylindrical structure with one end open. The piston (505) is slidably arranged inside the SMA element housing (504). The rod of the piston (505) extends outward through the open end of the SMA element housing (504). The SMA spring (501) and the bias spring (502) are both arranged between the end plate of the SMA element housing (504) and the piston (505).

4. The seabed-based adaptive leveling device based on shape memory alloy according to claim 3, characterized in that, The locking / releasing mechanism (503) adopts a normally closed electromagnetic braking structure, which is used to mechanically lock the current state after the adaptive leveling is completed by utilizing the power-off locking characteristic to avoid continuous energy consumption.

5. The seabed-based adaptive leveling device based on shape memory alloy according to claim 4, characterized in that, The normally closed electromagnetic braking structure is located at the open end of the SMA element housing (504) and is sealed and fixed by a sealing ring (506).

6. The seabed-based adaptive leveling device based on shape memory alloy according to claim 3, characterized in that, A temperature sensor is also installed on the SMA spring (501).

7. The seabed-based adaptive leveling device based on shape memory alloy according to claim 3, characterized in that, The SMA element housing (504) has a waterproof connector (507) on the closed end.

8. A seabed-based adaptive leveling method based on shape memory alloys, characterized in that, The seabed-based adaptive leveling device based on shape memory alloys according to any one of claims 1 to 7 includes the following steps: S100, The seabed-based adaptive leveling device carrying instruments and equipment is deployed in the seawater and sunk to the seabed. Due to the seabed topography, the seabed-based observation platform (100) of the seabed-based adaptive leveling device tilts. S200, in the leveling leg (200) in the tilted state, the leveling leg (200) supported at the high point is subjected to relatively large force, and the SMA actuator (500) of the leveling leg (200) is subjected to compressive stress; while the leveling leg (200) that is suspended or subjected to relatively small force is in a relaxed or low stress state. S300. For the leveling leg (200) with relatively large force, the compressive stress causes the SMA actuator (500) on the leveling leg (200) to undergo stress-induced martensitic phase transformation and shorten, thereby allowing the leveling leg (200) to yield and contract, and release stress. For the leveling leg (200) that is suspended or has relatively small force, the pressure sensor transmits the signal of the suspended or relatively small force leg to the heating circuit. The heating circuit applies a short-time pulse current to the SMA actuator (500) of the opposite leveling leg (200), which heats the SMA spring (501). The SMA spring (501) returns to its initial shape due to the shape memory effect, pushing the internal piston (505) to move radially outward, and the leveling leg (200) extends until the foot pad (400) at the bottom of the leveling leg (200) contacts the seabed and obtains support force. The S400 seabed-based observation platform (100) gradually adjusts to a horizontal state through a high contraction and low elongation adaptive adjustment process. When all the leveling legs (200) are in contact with the seabed and are under balanced force, the leveling ends, the normally closed electromagnetic brake is de-energized, and the length of all the leveling legs (200) is locked, and the adjustment process is completed. After the S500 and seabed-based observation platform (100) are leveled, the main control system is activated and the instruments and equipment begin to work according to the preset program.

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