Landing buffer system based on three-period minimal curved surface

Abstract

The invention belongs to the technical field of seabed landers, and particularly relates to a landing buffer system based on a three-period minimal curved surface, comprising: a base for mounting deep sea application equipment; the top ends of the buffering devices are fixed to the bottom of the base, supporting legs are connected to the bottom ends of the buffering devices, and the multiple buffering devices are arranged at the bottom of the base in the circumferential direction at equal intervals; and the multiple reverse thrust devices are arranged on the base in the circumferential direction at equal intervals and used for providing recoil force when landing on the seabed. The buffer device is provided with a TPMS porous structure, is made of memory alloy with a three-period extremely-small curved surface structure, has the capacity of being good in energy absorption effect and high in damping effect, can reduce the mass while guaranteeing the strength through the porous structure, can achieve controllable deformation of the memory alloy through temperature adjustment, and is suitable for large-scale popularization and application. The buffer device can be filled with magnetorheological fluid, and the rigidity and flexibility of the buffer structure can be controlled by controlling the change of the magnetic field.

Description

Technical Field

[0001] The present invention belongs to the technical field of seabed landers, and in particular relates to a landing buffer system based on a three-period minimal surface. Background Art

[0002] Deep-sea landers (or seabed landers) are high-tech equipment used to perform tasks in underwater environments. They are widely used in deep-sea exploration, seabed resource collection, scientific experiments, and environmental monitoring. With the development of deep-sea exploration technology, the demand for landers is growing, especially in missions that require precise operations on the seabed or long stays. The particularity of the deep-sea environment, such as extremely high water pressure, low temperature, strong flow rate, and the complexity of the seabed topography, makes the design and manufacture of such a lander face many challenges. Under these environmental conditions, the lander needs to have strong pressure resistance, stability, and efficient energy management capabilities. During landing and docking, the lander often experiences large impact forces and vibrations, which come from the contact between the lander and the seabed, or from the violent fluctuations of the water flow. In order to protect the structure of the lander and the internal precision instruments from damage, the buffer shock absorption system has become one of its key designs.

[0003] The role of buffer shock absorbers in deep-sea landers is very important. Deep-sea landers not only need to cope with complex underwater dynamic environments, but also need to be able to maintain structural integrity and functionality in extreme environments. The shock absorption system effectively absorbs impact energy and reduces the huge impact caused by landing or encountering water flow fluctuations, ensuring that the lander can successfully complete its mission without damage. These shock absorption systems usually rely on technologies such as hydraulics, pneumatics or springs to convert the impact from the seabed into heat energy or consume it in other ways. Especially in the deep sea, the extremely high water pressure and low temperature require the shock absorption system to not only have a strong energy absorption capacity, but also to ensure stability and reliability in long-term use. With the continuous deepening of deep-sea exploration and resource development, the design of buffer shock absorbers has been continuously optimized to adapt to more complex mission requirements and more stringent environmental conditions.

[0004] Traditional buffer and shock-absorbing devices have low strength and cannot meet the requirements of deep-sea exploration. If the strength of the buffer and shock-absorbing devices is improved, its mass will inevitably increase, making it inconvenient in transportation and maintenance.

[0005] TPMS are curved structures with the smallest local surface area at a given boundary. They are widely used as energy absorbers to reduce impact or explosion loads. Porous structures have shown great application potential in various fields due to their unique characteristics. These structures are not only lightweight, but also exhibit excellent mechanical properties due to their unique pore distribution. Therefore, we propose a landing cushioning system based on three-periodic minimal surfaces. Summary of the invention

[0006] The purpose of the present invention is to provide a landing cushioning system based on a three-periodic minimal surface to solve the above-mentioned problems.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A landing cushioning system based on a three-periodic minimal surface, comprising:

[0009] Base for mounting equipment for deep-sea applications;

[0010] A buffer device, the top end of which is fixed to the bottom of the base, the bottom end of which is connected to a support foot, and the buffer device is provided with a plurality of buffer devices which are circumferentially and evenly spaced at the bottom of the base;

[0011] A reverse thrust device is provided, and the reverse thrust devices are arranged on the base at equal intervals in the circumferential direction, and are used to provide a recoil force when landing on the seabed.

[0012] Optionally, the buffer device comprises:

[0013] A mounting frame, the mounting frame is an L-shaped structure, and a horizontal section of the mounting frame is fixedly connected to the base;

[0014] A first connecting rod, one end of which is hinged to the middle of the mounting frame, and the other end of the first connecting rod is hinged to one end of a fourth connecting rod, and the fourth connecting rod is arranged parallel to the vertical section of the mounting frame;

[0015] A second connecting rod, one end of which is hinged to the other end of the fourth connecting rod, the second connecting rod is arranged parallel to the first connecting rod, and the other end of the second connecting rod is hinged to the bottom end of the vertical section of the mounting frame;

[0016] A third connecting rod is transmission-connected to the fourth connecting rod, and a bottom end of the third connecting rod is connected to the supporting foot;

[0017] The buffer part has one end hinged to the middle part of the first connecting rod, and the other end of the buffer part is hinged to the horizontal section of the mounting frame.

[0018] Optionally, the third connecting rod is arranged in parallel with the fourth connecting rod, one end of a fifth connecting rod is hinged to the top end of the third connecting rod, and the other end of the fifth connecting rod is hinged to the hinge axis between the fourth connecting rod and the first connecting rod;

[0019] One end of a triangular plate is hinged to the middle of the fourth connecting rod, and the middle of the triangular plate is hinged to the hinge axis of the fourth connecting rod and the second connecting rod; the other end of the triangular plate is hinged to one end of a transmission rod, and the other end of the transmission rod is hinged to the hinge axis of the mounting frame and the first connecting rod.

[0020] Optionally, the buffer portion includes a damping buffer rod, a movable end of the damping buffer rod is hinged to the middle portion of the first connecting rod, and a fixed end of the damping buffer rod is hinged to the middle portion of the horizontal section of the mounting frame.

[0021] Optionally, the thrust reverser comprises:

[0022] A thrust reverser bracket, fixedly connected to the edge of the base;

[0023] The motor has a fixed end shaft connected to the reverse thrust bracket, and the output end shaft of the motor is connected to blades.

[0024] Optionally, the support foot comprises a support foot mounting tube, and the top end of the support foot mounting tube is axially connected to the bottom end of the third connecting rod;

[0025] A support leg piston is vertically slidable in the support leg installation cylinder, and the support leg installation cylinder and the support leg piston are limitedly matched;

[0026] The bottom end of the support piston is fixedly connected with a support plate;

[0027] An elastic portion is provided between the support foot mounting cylinder and the support foot piston.

[0028] Optionally, the elastic part includes a coaxially arranged TPMS buffer structure and a spring, the top ends of the TPMS buffer structure and the spring are fixedly connected to the inner wall of the bottom of the support foot mounting cylinder, the bottom ends of the TPMS buffer structure and the spring are fixedly connected to the inner wall of the top of the support foot piston, the TPMS buffer structure is made of a memory alloy, and the TPMS buffer structure is coaxially arranged in the spring.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] When in use, the deep-sea application equipment is installed through the base. After descending to the seabed, the descent speed of the base is first reduced by the reverse thrust device, and then the landing is achieved by contacting the seabed through the buffer device. The buffer device has a TPMS porous structure, which has good energy absorption effect, improved energy absorption capacity, and enhanced shock absorption effect. By setting it to a porous structure, the mass can be reduced while ensuring strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0032] Figure 1 It is a schematic diagram of the structure of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of the buffer device of the present invention;

[0034] Figure 3 It is a schematic diagram of the structure of the thrust reverser of the present invention;

[0035] Figure 4 This is a schematic diagram of the support leg structure of the present invention;

[0036] Figure 5 This is a schematic diagram of the three-periodic minimal surface unit structure of the present invention;

[0037] Figure 6 The design flow chart of the buffer structure of the TPMS structure of the present invention;

[0038] Figure 7 A comparison diagram of normalized energy absorption capabilities of different TPMS structures of the present invention;

[0039] Figure 8 This is a comparison diagram of specific dissipated energy under cyclic loading of different TPMS structures of the present invention;

[0040] Among them, 1. deep-sea application equipment; 2. base; 3. pump body; 4. heater; 5. reverse thrust device; 6. buffer device; 7. support foot; 501. reverse thrust bracket; 502. motor; 503. blade; 601. mounting frame; 602. first connecting rod; 603. transmission rod; 604. third connecting rod; 605. fourth connecting rod; 606. second connecting rod; 607. triangle plate; 608. fifth connecting rod; 609. damping buffer rod; 701. support foot mounting cylinder; 702. support foot piston; 703. TPMS buffer structure; 704. spring; 705. support foot plate. DETAILED DESCRIPTION

[0041] This embodiment proposes a buffer device that combines a three-period minimal surface (TPMS) structure, a memory alloy, and a magnetorheological damper, which is designed to meet the impact absorption and dynamic buffering requirements of deep-sea landers in extreme environments. The device makes full use of the lightweight, high-strength characteristics of the TPMS structure and its complex pore distribution to achieve effective dispersion of the huge impact force during deep-sea landing, and exhibits excellent energy absorption performance and buffering effects. The design of the TPMS structure enables it to provide efficient energy absorption under extreme load conditions, and is particularly suitable for the repeated effects of seabed impact and buoyancy adjustment on landers in deep-sea environments.

[0042] The introduction of shape memory alloys further enhances the recoverability of the buffer device. The core principle of the shape memory alloy is based on the reversible phase transition between martensite and austenite. When the shape memory alloy is in a low temperature state (martensite phase), it will deform when subjected to force loading; after heating to above the phase transition temperature (Af), the material can completely recover to its original shape. By rationally designing the shape memory effect, this buffer device can achieve structural self-reset after deep-sea landing impact, thereby ensuring the stable performance and high reusability of the device in multiple landing missions.

[0043] In addition, the variable damping performance of the magnetorheological damper enables the device to accurately respond to complex load changes during deep-sea landings. Magnetorheological fluid consists of tiny magnetic particles suspended in a base liquid. When there is no magnetic field, it is in a low-viscosity, low-resistance state and can flow freely; when a magnetic field is applied, the magnetic particles quickly arrange themselves to form a chain structure, greatly increasing viscosity and resistance. By adjusting the strength of the external magnetic field, the damping performance can be dynamically controlled to adapt to the changing landing conditions and impact intensity in the deep-sea environment.

[0044] The present invention designs a high-performance buffer device suitable for deep-sea landers by integrating the efficient energy absorption of the TPMS structure, the shape memory effect of the memory alloy, and the variable damping characteristics of the superelasticity and magnetorheological damper. The device can effectively absorb the landing impact force in the deep-sea environment and maintain efficient energy management and dynamic adaptability in multiple missions, providing reliable technical support for deep-sea exploration missions.

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] Reference Figures 1 to 8 The present invention discloses a landing cushioning system based on a three-periodic minimal surface, comprising:

[0048] A base 2, used for installing the deep-sea application equipment 1;

[0049] A buffer device 6, the top end of which is fixed to the bottom of the base 2, the bottom end of which is connected to a support leg 7, and a plurality of buffer devices 6 are provided and are circumferentially evenly spaced at the bottom of the base 2;

[0050] The reverse thrust device 5 is provided in plurality, and the plurality of reverse thrust devices 5 are circumferentially evenly spaced on the base 2 to provide a recoil force when landing on the seabed.

[0051] When in use, the deep-sea application equipment 1 is installed through the base 2. After descending to the seabed, the descent speed of the base 2 is first reduced by the reverse thrust device 5, and then the cushioning device 6 contacts the seabed to achieve landing. The cushioning device 6 has a TPMS porous structure, which has good energy absorption effect, improved energy absorption capacity, and enhanced shock absorption effect. Moreover, by being set as a porous structure, the mass can be reduced while ensuring strength.

[0052] Compared with the prior art which uses springs and damping rods for landing cushioning, the device can significantly improve landing cushioning and has a longer service life.

[0053] As an optional implementation, the buffer device 6 includes:

[0054] A mounting frame 601, the mounting frame 601 is an L-shaped structure, and the horizontal section of the mounting frame 601 is fixedly connected to the base 2;

[0055] A first connecting rod 602, one end of which is hinged to the middle of the mounting frame 601, and the other end of the first connecting rod 602 is hinged to one end of a fourth connecting rod 605, and the fourth connecting rod 605 is arranged parallel to the vertical section of the mounting frame 601;

[0056] A second connecting rod 606, one end of which is hinged to the other end of the fourth connecting rod 605, the second connecting rod 606 is arranged parallel to the first connecting rod 602, and the other end of the second connecting rod 606 is hinged to the bottom end of the vertical section of the mounting frame 601;

[0057] The third connecting rod 604 is transmission-connected to the fourth connecting rod 605, and the bottom end of the third connecting rod 604 is connected to the support foot 7;

[0058] The buffer part has one end hinged to the middle of the first connecting rod 602 , and the other end of the buffer part is hinged to the horizontal section of the mounting frame 601 .

[0059] As an optional implementation, the third link 604 is arranged in parallel with the fourth link 605, the top end of the third link 604 is hinged with one end of the fifth link 608, and the other end of the fifth link 608 is hinged at the hinge axis between the fourth link 605 and the first link 602;

[0060] One end of a triangular plate 607 is hinged to the middle of the fourth connecting rod 605, and the middle of the triangular plate 607 is hinged to the hinge axis of the fourth connecting rod 605 and the second connecting rod 606; the other end of the triangular plate 607 is hinged to one end of a transmission rod 603, and the other end of the transmission rod 603 is hinged to the hinge axis of the mounting frame 601 and the first connecting rod 602.

[0061] As an optional implementation, the buffer portion includes a damping buffer rod 609 , a movable end of the damping buffer rod 609 is hinged to the middle of the first connecting rod 602 , and a fixed end of the damping buffer rod 609 is hinged to the middle of the horizontal section of the mounting frame 601 .

[0062] When a traditional landing buffer lands, its supporting feet are hinged to the base 2 through a buffer. When the landing point is uneven, in order to ensure that the base 2 is level, the lengths and angles of the supporting feet are different. At this time, it is easy for the base 2 to deviate from the preset landing point and cause an error. Therefore, a method is needed that can ensure that the base 2 is not easily offset during vertical lifting even if the landing point is in a rugged area.

[0063] In the buffer device 6, the first parallelogram structure is composed of the first connecting rod 602, the fourth connecting rod 605, the vertical section of the mounting frame 601 and the second connecting rod 606, and the second parallelogram structure is composed of the fourth connecting rod 605, the third connecting rod 604, the fifth connecting rod 608 and the triangular plate 607. The transmission rod 603 is used for transmission between the two parallelogram structures. The support foot 7 is connected to the bottom of the third connecting rod 604. When the support foot 7 touches the bottom, the third connecting rod 604 rises, driving the triangular plate 607 to rotate, and at the same time drives the second parallelogram structure to move. The triangular plate 607 pulls the transmission rod 603 to pull the mounting frame 601 to move and drive the first parallelogram structure to move. The displacements generated by the two parallelogram structures offset each other, and finally appear as the third connecting rod 604 vertically moving. When the first connecting rod 602 moves, the damping buffer rod 609 realizes the shock absorbing and buffering effect, thereby ensuring that the landing point and the preset point are not offset when the base 2 lands.

[0064] As an optional implementation, the thrust reverser 5 includes:

[0065] The thrust reverser bracket 501 is fixed to the edge of the base 2;

[0066] The fixed end shaft of the motor 502 is connected to the reverse thrust support 501 , and the output end shaft of the motor 502 is connected to the blade 503 .

[0067] Before landing, the motor 502 drives the blades 503 to rotate to generate reverse thrust, thereby reducing the descending speed of the base 2 and further reducing the impact during landing.

[0068] As an optional implementation, the support leg 7 includes a support leg mounting tube 701, and the top end of the support leg mounting tube 701 is axially connected to the bottom end of the third connecting rod 604;

[0069] A support leg piston 702 is vertically slidable in the support leg installation cylinder 701, and the support leg installation cylinder 701 and the support leg piston 702 are limitedly matched;

[0070] The bottom end of the support piston 702 is fixedly connected with a support plate 705;

[0071] An elastic portion is provided between the support leg mounting cylinder 701 and the support leg piston 702 .

[0072] As an optional embodiment, the elastic part includes a coaxially arranged TPMS buffer structure 703 and a spring 704, the top ends of the TPMS buffer structure 703 and the spring 704 are fixedly connected to the bottom inner wall of the support foot mounting cylinder 701, and the bottom ends of the TPMS buffer structure 703 and the spring 704 are fixedly connected to the top inner wall of the support foot piston 702, the TPMS buffer structure 703 is made of a memory alloy, and the TPMS buffer structure 703 is coaxially arranged in the spring 704.

[0073] A partition is provided between the TPMS buffer structure 703 and the spring 704 , and the TPMS buffer structure 703 and the spring 704 play a buffering role at the same time.

[0074] As an additional implementation, the TPMS buffer structure 703 is made of a memory alloy having a three-period minimal surface structure, and the spring 704 is a common spring.

[0075] The spring 704 is sleeved on the outer side of the TPMS buffer structure 703 .

[0076] One of the TPMS buffer structure 703 and the spring 704 serves as a main spring, and the other serves as a secondary spring. Since the shape memory alloy has a slow rapid response capability, that is, low deformation efficiency, the secondary spring can perform energy compensation before the shape memory alloy reaches the ideal or target shape, thereby playing a secondary energy absorption role.

[0077] An inlet and an outlet are respectively provided on the side walls of the support foot mounting cylinder 701 and the support foot piston 702 for the entry and discharge of heated seawater. Meanwhile, the TPMS buffer structure 703 is made of a memory alloy having a three-period minimal surface structure, and the deformation of the memory alloy can be controlled by temperature regulation.

[0078] Embodiment 2:

[0079] As an additional implementation, the heating pump water unit includes:

[0080] Pump body 3, pump body 3 is fixedly connected to base 2, and the water outlet end of pump body 3 is connected with the inlet opening on support foot mounting cylinder 701 through a hose;

[0081] The heating part is arranged on one side of the pump body 3, the water outlet end of the heating part is connected with the water inlet end of the pump body 3, and the water inlet end of the heating part is connected with the outside, and the heating part is used to increase the water temperature in the hose.

[0082] As an additional implementation, the heating unit includes a heater 4 , a water inlet end of the heater 4 is connected to the outside, and a water outlet end of the heater 4 is connected to the water inlet end of the pump body 3 .

[0083] In this embodiment, when the device sinks to the bottom of the sea, because the water pressure at the bottom of the sea is higher than the water pressure at the sea surface, seawater can be pumped into the support foot installation cylinder 701 through the pump body 3, so that the support foot installation cylinder 701 is filled with seawater, thereby achieving a balance of the internal and external pressure difference. Subsequently, the seawater is heated by the heater 4, so that the temperature of the seawater entering the support foot installation cylinder 701 is higher than the external temperature. By controlling the temperature of the seawater entering the support foot installation cylinder 701, the deformation of the TPMS buffer structure 703 can be controlled.

[0084] As an additional implementation method, the heater 4 can be selected as an electromagnetic heating device. By setting a copper tube connected to the water inlet end of the pump body 3, and setting an electromagnetic heating device on the outside of the copper tube, the copper tube is heated by electromagnetic force, and the water flowing through the copper tube will quickly heat up and then enter the corresponding component through the hose.

[0085] The hose is selected to be a high temperature and high pressure resistant pipe and is wrapped with an insulation layer on the outside.

[0086] Embodiment 3:

[0087] As an additional implementation, the TPMS buffer structure 703 is filled with magnetorheological fluid, and a cavity for installing the electromagnetic coil is provided in the interlayer between the TPMS buffer structure 703 and the spring 704. When the electromagnetic is activated, the magnetic field generated causes the magnetorheological fluid to solidify, thereby increasing the resistance. By adjusting the intensity of the electromagnetic activation, the damping force of the damper can be accurately controlled, and the damping force can be adjusted in real time according to demand.

[0088] The electromagnetic coil is a spring wire structure and is coaxially wound outside the TPMS buffer structure 703 .

[0089] The outside of the TPMS buffer structure 703 is wrapped with a flexible sheath, which can prevent the magnetorheological fluid from overflowing and does not hinder the deformation of the TPMS buffer structure 703. Due to the incompressible property of the magnetorheological fluid, the magnetorheological fluid is filled in the TPMS buffer structure 703 but not full, so that there is space for the magnetorheological fluid to flow inside the TPMS buffer structure 703 when it is deformed.

[0090] Embodiment 4:

[0091] Regarding the selection of TPMS configuration, please refer to the following steps.

[0092] The parametric coordinates of the three-periodic minimal surface (TPMS) can be derived through the Weierstrass function. The geometric structure of the TPMS can be solved by the following mathematical expression:

[0093]

[0094] Among them, Re is the coefficient obtained by calculating the value from a fixed point ω0 to a variable point ω. In this form, the parametric coordinates of the TPMS surface can be obtained. Next, the geometric structure of the TPMS is derived using the level set approximation equation defined by the Fourier series. Among them, ω0 is a fixed complex number that defines the starting point of the integration, ω is the upper limit of the integration, and the variable τ used in the integration process defines the parameterization of the path. The function R(τ) is closely related to the geometric structure of the TPMS (three-periodic minimal surface) and is used to describe the shape and thickness of the surface; in three-dimensional space, the parameters x, y, and z represent the spatial coordinates of the TPMS, the polar angle θ describes its rotation angle in the polar coordinate system, and the parameter t is used to define the change path of a point on the surface.

[0095] The equation is as follows:

[0096]

[0097] Where k is the reciprocal vector, α(k) is the phase shift, the structure factor F(k) is the amplitude associated with a given k, and r is the vector of spatial positions. Ψ(r) represents a periodic function that describes a specific spatial three-periodic minimal surface (TPMS) structure. When the series is truncated to the leading term, a function φ consisting of a combination of trigonometric functions is generated, satisfying the following equation:

[0098] φ(x,y,z)=c,

[0099] Among them, X = k·2π·x / l, Y = k·2π·y / l, Z = k·2π·z / l. l represents the macroscopic size of the entire surface, and k is a periodic parameter. Through the above steps, the key geometric parameters required for the TPMS surface can be determined, thus laying the foundation for the subsequent selection of the TPMS structure.

[0100] Table 1 Level set approximate equations for eight TPMS

[0101]

[0102] The eight TPMS in the above steps were subjected to mechanical compression tests. TPMS lattices were prepared using 316L stainless steel powder as raw material. The mechanical compression tests were also conducted. The specific details are as follows: each configuration was modeled using three densities (20%, 30%, and 40%). The specific c values ​​for modeling are shown in the following table.

[0103] Table 2 c values ​​of eight TPMS dot matrix at three relative densities

[0104]

[0105]

[0106] The mechanical properties of the TPMS lattice were analyzed using a representative porous material performance model theory, namely the Gibson-Ashby (GA) model theory based on a simplified cubic pore structure to analyze the test results. The GA model describes the relationship between mechanical properties and relative density, linking relative density to mechanical properties. The energy W absorbed per unit volume of the TPMS results can be characterized as a function of relative density using a power law based on the classical honeycomb solid theory, as follows;

[0107]

[0108] Among them, σ y is the yield strength of the substrate, C i and n i (i=1) is the geometric coefficient and index of the TPMS matrix fitting, ρ * is the actual relative density.

[0109] When the fitting index n1 is 1, the lattice exhibits a standard tensile-dominated deformation mode, and when n1 is 1.5, the lattice exhibits a standard bending-dominated deformation mode. As can be seen from the figure, the n1 values ​​of the eight TPMS lattices are in the range of 1.63-2.43, all greater than 1.5, showing a bending-dominated deformation mode. It is worth noting that the bending-dominated deformation mode contributes to energy absorption. The bending-dominated deformation mode helps to improve the energy absorption capacity, so it is of great significance in practical applications.

[0110] The four configurations of P, G, D, and IWP in the above steps were subjected to cyclic loading tests. TPU material was used for preparation;

[0111] The cyclic loading test was carried out for more than 20 cycles. The research results showed that the D lattice has the best energy dissipation capacity because it can withstand more axial stress.

[0112] The D configuration is selected as the main structure of the TPMS buffer. The buffer variable energy absorption structure in the buffer device is designed, and the nickel-titanium alloy material is selected for its preparation.

[0113] Since the TPMS structure exhibits periodic symmetry in three independent directions, this symmetry can be infinitely reproduced through the repetition of its unit cell. The cylindrical model can be discretized using a mapping grid, and the TPMS unit distorted by the shape function can be filled in the mapping grid to form a cylindrical mapping structure.

[0114] The TPMS buffer structure based on memory alloy material can adopt the following main control methods:

[0115] The TPMS buffer structure is heated by using a PWM control method, that is, when the signal output by the PWM pulse is a high level 1, the TPMS buffer structure is powered on for heating; when the signal output by the PWM pulse is a low level 0, the current of the TPMS buffer structure is disconnected, and the power-on and power-off time of the TPMS buffer structure is controlled by adjusting the PWM signal duty cycle. When the TPMS buffer structure is powered on, it absorbs heat and its temperature rises, and when it is powered off, it releases heat and its temperature drops. By controlling the power-on and power-off time to keep the temperature of the TPMS buffer structure between Af and the limit temperature, the TPMS buffer structure can be kept in a deformable state.

[0116] Since the deformation efficiency of the memory alloy material is slow, based on the PWM pulse heating control, the method of introducing heated seawater into the support leg mounting cylinder 701 in Example 2 is adopted for auxiliary control, thereby further accelerating the deformation efficiency.

[0117] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0118] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A landing cushion system based on a three-periodic minimal surface, characterized in that: include: A base (2) for mounting the deep-sea application equipment (1); A buffer device (6), the top end of which is fixed to the bottom of the base (2); the bottom end of the buffer device (6) is connected to a support foot (7); and the buffer device (6) is provided with a plurality of buffer devices (6) which are circumferentially evenly spaced and arranged at the bottom of the base (2); A reverse thrust device (5), wherein a plurality of the reverse thrust devices (5) are provided, and the plurality of reverse thrust devices (5) are arranged on the base (2) at equal intervals in the circumferential direction, and are used to provide a recoil force when landing on the seabed.

2. A landing cushioning system based on a three-periodic minimal surface according to claim 1, characterized in that: The buffer device (6) comprises: A mounting frame (601), wherein the mounting frame (601) is an L-shaped structure, and a horizontal section of the mounting frame (601) is fixedly connected to the base (2); A first connecting rod (602), one end of which is hinged to the middle of the mounting frame (601); the other end of the first connecting rod (602) is hinged to one end of a fourth connecting rod (605); the fourth connecting rod (605) is arranged parallel to the vertical section of the mounting frame (601); A second connecting rod (606), one end of which is hinged to the other end of the fourth connecting rod (605), the second connecting rod (606) is arranged parallel to the first connecting rod (602), and the other end of the second connecting rod (606) is hinged to the bottom end of the vertical section of the mounting frame (601); A third connecting rod (604) is transmission-connected to the fourth connecting rod (605), and the bottom end of the third connecting rod (604) is connected to the supporting foot (7); The buffer part has one end hinged to the middle part of the first connecting rod (602), and the other end of the buffer part is hinged to the horizontal section of the mounting frame (601).

3. The landing cushioning system based on a three-periodic minimal surface according to claim 2, characterized in that: The third connecting rod (604) is arranged in parallel with the fourth connecting rod (605), the top end of the third connecting rod (604) is hinged to one end of the fifth connecting rod (608), and the other end of the fifth connecting rod (608) is hinged to the hinge axis between the fourth connecting rod (605) and the first connecting rod (602); The middle part of the fourth connecting rod (605) is hinged to one end of a triangular plate (607), and the middle part of the triangular plate (607) is hinged to the hinge axis of the fourth connecting rod (605) and the second connecting rod (606); the other end of the triangular plate (607) is hinged to one end of a transmission rod (603), and the other end of the transmission rod (603) is hinged to the hinge axis of the mounting frame (601) and the first connecting rod (602).

4. The landing cushioning system based on a three-periodic minimal surface according to claim 3, characterized in that: The buffer part comprises a damping buffer rod (609), the movable end of the damping buffer rod (609) is hinged to the middle of the first connecting rod (602), and the fixed end of the damping buffer rod (609) is hinged to the middle of the horizontal section of the mounting frame (601).

5. The landing cushioning system based on a three-periodic minimal surface according to claim 1, characterized in that: The thrust reverser (5) comprises: A thrust reverser bracket (501) fixedly connected to the edge of the base (2); The motor (502) has a fixed end shaft connected to the reverse thrust support (501), and the output end shaft of the motor (502) is connected to a blade (503).

6. The landing cushioning system based on a three-periodic minimal surface according to claim 2, characterized in that: The support foot (7) comprises a support foot mounting tube (701), the top end of the support foot mounting tube (701) being axially connected to the bottom end of the third connecting rod (604); A support leg piston (702) is vertically slidable in the support leg installation cylinder (701), and the support leg installation cylinder (701) and the support leg piston (702) are limitedly matched; The bottom end of the support piston (702) is fixedly connected with a support plate (705); An elastic portion is provided between the support foot mounting cylinder (701) and the support foot piston (702).

7. The landing cushioning system based on a three-periodic minimal surface according to claim 6, characterized in that: The elastic part comprises a coaxially arranged TPMS buffer structure (703) and a spring (704); the top ends of the TPMS buffer structure (703) and the spring (704) are fixedly connected to the bottom inner wall of the support foot mounting cylinder (701); the bottom ends of the TPMS buffer structure (703) and the spring (704) are fixedly connected to the top inner wall of the support foot piston (702); the TPMS buffer structure (703) is made of a memory alloy; and the TPMS buffer structure (703) is coaxially arranged in the spring (704).

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