Electromagnetic active suspension for lunar surface bearing vibration reduction and control method thereof

Abstract

The invention provides an electromagnetic active suspension for lunar surface bearing vibration reduction and a control method of the electromagnetic active suspension, and relates to the technical field of extraterrestrial star surface carrying equipment. The active suspension comprises a terrain self-adaptive four-connecting-rod mechanism, a bionic damping and buffering mechanism, a cattail-imitating multi-layer composite main bearing rod and an active adjusting unit; the terrain self-adaptive four-connecting-rod mechanism can adapt to irregular terrain changes and keep good wheel-ground contact; the bionic damping and buffering mechanism can reduce impact transmission; the cattail-imitating multi-layer composite main bearing bar comprises a compact surface layer, a gradient cell hole layer and a longitudinal reinforcing bundle core, and has high specific strength, buckling resistance and ellipticity resistance. The active adjusting unit is used for achieving active control over the height and side inclination of the carrying platform. Damping and buffering, wheel end dynamic adaptation, high-bearing-capacity supporting and accurate active posture adjustment can be achieved in the lunar surface environment, and therefore the stability and reliability of the carrying platform on the lunar surface are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of suspension and vibration reduction for autonomous moving equipment on the lunar surface, specifically to an electromagnetic active suspension for vibration reduction under lunar surface loads and its control method. Background Technology

[0002] With the deepening construction of lunar research stations and the exploration and development of strategic resources, extremely high demands are placed on the mobility, load-bearing efficiency, and operational stability of lunar surface transport equipment. The lunar surface has drastically varied terrain, with numerous rocks, craters, slopes, soft lunar soil areas, and debris zones of varying sizes. Since the lunar surface gravity is approximately one-sixth that of Earth, the wheel-to-ground contact force of lunar surface transport equipment fluctuates dramatically during operation, making it more prone to phenomena such as wheel suspension, slippage, sudden heave, and amplified impact peaks. This results in uneven suspension stress and drastic changes in the attitude of the transport platform.

[0003] Existing lunar surface traversal devices mostly employ rocker arm suspension, swing arm suspension, or linear spring-damper structures, which generally suffer from the following shortcomings: ① Insufficient terrain adaptability: Passive suspensions rely on their own geometric constraints to adapt to wheel-end height differences, and cannot actively control them. Once one wheel encounters a sudden change in terrain, the transport platform's attitude will exhibit significant tilting. ② Weak shock absorption capacity: Traditional linear spring-damper systems perform poorly under low-frequency, large-displacement disturbances, and the impact peak is easily transmitted directly to the transport platform. ③ The load-bearing structure is prone to bending: Existing solid or single-layer hollow load-bearing members are at risk of local buckling, ellipticization, and crushing under eccentric loading or impact loads. ④ Limited active attitude control capability: Some suspensions are only equipped with a single linear actuator, which cannot achieve independent left and right adjustment, nor can it provide rapid and precise active compensation for the transport platform's attitude.

[0004] Especially in large transport equipment, due to the large size of the transport platform and the concentrated distribution of loads, the suspension not only needs to absorb the complex terrain, but also must have the ability to actively adjust its attitude in order to maintain the stable transport and operation of the transport platform in a low gravity environment.

[0005] Therefore, there is an urgent need for an innovative suspension system that integrates terrain adaptation, biomimetic vibration reduction, high load-bearing capacity, and active attitude adjustment capabilities to improve the adaptability and reliability of future lunar transport equipment. Summary of the Invention

[0006] To address the shortcomings of the prior art, the present invention aims to provide an electromagnetic active suspension and its control method for vibration reduction on the lunar surface. Through the coordinated operation of passive mechanisms and active control, it can achieve vibration reduction and buffering, dynamic wheel-end adaptation, high load-bearing support, and precise active attitude adjustment in the lunar environment, thereby significantly improving the stability and reliability of the transport platform on the lunar surface.

[0007] Specifically, in the first aspect, the present invention provides an electromagnetic active suspension for lunar surface bearing vibration reduction, which includes a transport platform, a control system and suspension units symmetrically arranged on both sides. Each suspension unit includes a drive wheel assembly, a biomimetic damping and buffer mechanism, a terrain-adaptive four-bar linkage, a cattail-inspired multi-layer composite main load-bearing bar and an active adjustment unit arranged vertically from bottom to top. The drive wheel assembly is hinged to the bottom of the bionic shock absorption mechanism. The bionic shock absorption mechanism includes an upper connecting rod, a lower connecting rod, a gear transmission assembly, a first short rod, a second short rod, a third short rod, a horizontal spring, a first oblique spring, a second oblique spring, and an adjusting motor assembly. The gear transmission assembly includes a first gear and a second gear that mesh with each other. The first ends of the first, second, and third short rods intersect at a point and are hinged to the drive wheel assembly. The second end of the first short rod is fixedly connected to the first gear, the second end of the second short rod is fixedly connected to the second gear, and the second end of the third short rod is fixedly connected to... The first end of the lower link is hinged, the second end of the lower link is connected to the first end of the second inclined spring, the second end of the second inclined spring is connected to the second gear, the third end of the lower link is connected to the first end of the adjusting motor assembly, the two ends of the horizontal spring are connected to the first gear and the second gear respectively, the first end of the first inclined spring is connected to the first gear, the second end of the first inclined spring is connected to the first end of the upper link, the second end of the upper link is connected to the first end of the adjusting motor assembly, and the third end of the upper link and the second end of the adjusting motor assembly are connected to the terrain-adaptive four-bar linkage respectively. The active adjustment unit includes a first linear motor, a second linear motor, a third linear motor, and a fourth linear motor. Each of the first, second, third, and fourth linear motors is equipped with a stroke sensor. The body ends of the first, second, third, and fourth linear motors are connected to the multi-layer composite main load-bearing rod of the imitation cattail. The push rod ends of the first, second, third, and fourth linear motors are connected to the bottom of the transport platform through ball joints. The tilt angle control and overall height adjustment of the transport platform are realized through differential or synchronous extension and retraction.

[0008] Preferably, the imitation cattail multilayer composite main load-bearing rod includes an outer dense epidermal layer, a middle gradient pore structure, and longitudinal bundle nuclei. The middle gradient pore structure, from the outside to the inside, includes an outer small pore region, an intermediate transitional pore region, an inner large pore region, and a central converging pore region. The pore size of the outer small pore region and the central converging pore region is smaller than the pore size of the intermediate transitional pore region, and the pore size of the intermediate transitional pore region is smaller than the pore size of the inner large pore region. Three longitudinal bundle nuclei are arranged, and the angle between the centers of two adjacent longitudinal bundle nuclei is [missing information]. .

[0009] Preferably, the outer axial direction of the imitation cattail multilayer composite main load-bearing rod is uniformly provided with multiple imitation bamboo joint reinforcing rings, and the middle transition cell pore area is axially staggered with transverse reinforcing cell walls, which are used to constrain the radial deformation of the cell pore structure, transmit transverse shear force, and at the same time disperse the supporting force of the longitudinal bundle nucleus to the entire gradient cell pore layer.

[0010] Preferably, the terrain-adaptive four-bar linkage includes two parallel upper parallel links, two parallel lower parallel links, an upper side rod, a lower side rod, and two intermediate swing rods. The two sides of the lower side rod are respectively hinged to the upper link of the biomimetic shock absorption and buffer mechanism and the adjusting motor assembly. The first end and the second section of the cattail-like main load-bearing rod are respectively fixedly connected to the middle position of the two intermediate swing rods.

[0011] Preferably, the control system is located below the transport platform, and the control system includes a controller and an attitude sensor, with the attitude sensor located below the controller.

[0012] Preferably, the first short rod is the main force-transmitting short rod, the second short rod is the secondary force-transmitting short rod, and the third short rod is the geometric constraint short rod. The main force-transmitting short rod, the secondary force-transmitting short rod, and the geometric constraint short rod introduce the vertical load at the wheel end into the lower connecting rod. The main force-transmitting short rod and the secondary force-transmitting short rod extend the horizontal spring through the gear set. The geometric constraint short rod is used to maintain the planar motion relationship between the connecting rod and the wheel end structure. The upper connecting rod and the lower connecting rod are respectively fixedly connected to a cylindrical gear and mesh with it at a speed ratio of 1:1 through the gear transmission set. The upper connecting rod and the lower connecting rod achieve rigid coupling through the gear transmission set. When the wheel end is subjected to an instantaneous impact through the lower connecting rod, the relative positions of the upper connecting rod and the lower connecting rod remain consistent. Changing the geometric position of the contact point between the upper connecting rod and the lower connecting rod at the periphery of the gear can adjust the force and elongation of the horizontal spring and the oblique spring. The horizontal spring is arranged laterally along the connecting rod, and the two oblique springs are respectively connected to the upper connecting rod and the lower connecting rod. Angle arrangement.

[0013] Secondly, the present invention provides a control method for an electromagnetic active suspension for lunar surface load-bearing vibration reduction, comprising the following steps: S1. Define comprehensive indicators First perturbation threshold and the second perturbation threshold ,and ; ; in, All are normalized scaling factors; Assigning weights to each item. The tilting speed of the transport platform. For the tracking error of the transport platform height, Due to the difference in travel distance between the two sides of the transport platform, This is an estimate of the roll channel disturbance. This represents the height channel disturbance value; S2, when At that time, the bionic shock absorption and buffer mechanism alone or in combination with the terrain-adaptive four-bar linkage absorbs and adapts to terrain disturbances. S3, when At the same time, the active adjustment unit controls the displacement increment of the linear motor using a single-sided priority differential strategy, prioritizing the suppression of roll while also considering height. The specific steps are as follows: S31. Judgment of the significance of lateral tilt: S32. Compare the absolute values ​​of the tilt angle of the transport platform. Threshold for judging roll angle The relationship between them determines whether tilting has occurred. In this case, it is determined that the transport platform has not tilted. S33, when If this is the case, it is determined that roll suppression is needed, and single-sided priority differential adjustment is activated. The average travel margin of the first linear motor and the second linear motor on the first side is calculated respectively. Average travel margin of the third and fourth linear motors on the second side ;like If so, the first side is selected as the priority adjustment side; if In this case, the second side is selected as the priority adjustment side; S4, when At this time, the active adjustment unit enters the active control mode, prioritizing differential attitude stabilization on both sides. After the attitude of the transport platform stabilizes, synchronous height recovery on both sides is performed, specifically including: S41. Dual-sided differential attitude stabilization: Perform dual-sided differential adjustment on both linear motors as described in step S33 to quickly suppress the tilt angle of the transport platform to a safe range until the tilt angle meets the requirements. ,in For attitude safety threshold, and keep time , The steady-state threshold; S42. Synchronous Height Recovery on Both Sides: After differential attitude stabilization on both sides, the height error of the transport platform is judged. If... Then, perform bilateral synchronous adjustment until the height error of the transport platform meets the requirements. , Once the high safety error threshold is reached, the high-level phase is determined to be complete, and the process returns to step S1.

[0014] Preferably, in steps S3, S41, and S42, the displacement increment of each linear motor is calculated using the following formula: ; in, This is a first-side group level instruction. This is a second-side group level instruction, specifically: ; in, Differential displacement on both sides Simultaneous displacement on both sides These are the weighting coefficients. As a priority indicator variable, , This indicates that the first side has priority; Indicates symmetrical differential; The second side takes priority; in step S3, take =1, take in step S41 =0, take in step S42 =1, , This represents the displacement increment of the i-th linear motor. Assign weights to the i-th linear motor based on its travel margin.

[0015] Preferably, the differential displacement on both sides and synchronous displacement on both sides Control quantity output by sliding mode controller , The following mapping relationship was used to calculate: ; in, The control allocation matrix elements are determined based on the dynamic characteristics of the suspension system.

[0016] Preferably, in step S3, when the computational load allows, the displacement increments of the linear motors on both sides are optimized and constrained during the control process: The linear motor travel constraint equations are constructed as follows: in For decision variable vectors This is a diagonal matrix representing the health status of the first, second, third, and fourth linear motors. Construct the rate of change constraint equation: in, No. The displacement increment of the motor in the previous control cycle. No. The maximum allowable rate of change of the motor, Motor displacement increment; The instruction matching constraint equations are constructed as follows: Construct the overall control objective function for the control system: ; in, To minimize total control energy; To prevent the depletion of penalty items; This is a smoothness penalty term; These are the weighting coefficients; This is the dynamic protection coefficient; For the first The real-time travel margin of the motor; Small positive numbers that prevent division by zero; This is the optimized solution for the previous control cycle.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The bionic buffer mechanism of the present invention adopts a three-short rod-gear-spring coupling design, which can realize the stepped energy absorption characteristics of low stiffness-medium stiffness-high stiffness. According to different disturbance levels, it can accurately match impact loads of different intensities, significantly reduce the peak impact value at the wheel end, and effectively protect the whole structure and core components.

[0018] (2) The terrain-adaptive four-bar linkage of the present invention can adapt to a wide range of terrain height undulations through the optimized configuration of the four-bar linkage, ensuring that the wheel end is always in close contact with the lunar surface, and improving the travel stability and lunar surface adhesion under complex terrain.

[0019] (3) The active adjustment unit of the present invention is driven by four linear motors, which can realize left and right differential adjustment and quickly suppress tilt disturbance; at the same time, the height of the transport platform is precisely controlled through the synchronous adjustment mechanism to ensure the stability and controllability of the transport platform's posture during operation.

[0020] (4) The multi-layer composite main load-bearing bar of the present invention draws on the multi-layer gradient structure design of cattail. The load-bearing structure has high specific strength characteristics. While achieving lightweight, it can effectively avoid elliptical deformation or bending failure of the load-bearing bar under large load, thereby improving the structural load-bearing reliability and service life.

[0021] (5) The present invention adopts an active-passive coupling control strategy. Small disturbances are absorbed by passive components such as biomimetic damping and buffering mechanism and terrain adaptive four-bar linkage mechanism. As the disturbance increases, it is compensated in real time by active adjustment unit, so that the whole system can take into account both excellent compliance and stable operation performance. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the electromagnetic active suspension for lunar surface bearing vibration reduction according to the present invention; Figure 2 This is a cross-sectional schematic diagram of the cattail-inspired multi-layer composite main load-bearing rod structure of the present invention; Figure 3 This is a schematic longitudinal section view of the multi-layer composite main load-bearing rod structure of the present invention, which imitates cattail. Figure 4 This is a schematic diagram of the terrain-adaptive four-bar linkage mechanism of the present invention; Figure 5 This is a schematic diagram of the biomimetic shock absorption and buffer mechanism of the present invention; Figure 6 This is a schematic diagram of the arrangement of the four linear motors of the present invention; Figure 7 This is a three-dimensional structural schematic diagram of the electromagnetic active suspension for lunar surface bearing vibration reduction according to the present invention; Figure 8 This is one of the schematic diagrams illustrating the working principle of the biomimetic shock absorption and buffer mechanism of the present invention; Figure 9 This is the second schematic diagram illustrating the working principle of the biomimetic shock absorption and buffer mechanism of the present invention; Figure 10 This is a flowchart illustrating the passive response-active attitude adjustment collaborative process of the electromagnetic active suspension for lunar surface load-bearing vibration reduction according to the present invention. Detailed Implementation

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0024] Specifically, in a first aspect, the present invention provides an electromagnetic active suspension for vibration reduction on the lunar surface, such as... Figures 1 to 7 As shown, it includes a transport platform 6, a control system 7, and suspension units symmetrically arranged on both sides. Each suspension unit includes a drive wheel assembly 2, a bionic shock absorption mechanism 3, a terrain-adaptive four-bar linkage 1, a cattail-inspired multi-layer composite main load-bearing bar 4, and an active adjustment unit 5 arranged vertically from bottom to top.

[0025] The drive wheel assembly 2 is hinged at the bottom to the biomimetic shock absorption mechanism 3. The drive wheel assembly 2 is a conventional drive wheel structure, which mainly includes the drive wheel and the hub motor. The drive wheel is used to contact the lunar surface to achieve vertical support and load bearing for the transport equipment, and also provides tangential driving force for the vehicle through the hub motor. It is the common point of action for the power input and load input of the suspension system.

[0026] The active suspension system of this embodiment is applied to the lunar surface. The two drive wheels can self-balance the left and right sides of the entire transport equipment, adapting to the low gravity environment of the lunar surface (1 / 6g), with each wheel possessing a large load-bearing capacity. To adapt to the lunar environment, including lunar dust, basic dustproof and sealing measures are adopted at the drive wheels and connecting parts to reduce the impact of lunar dust on the moving hinges and transmission interfaces. Since the structural details of the drive wheels are not part of the core content of the suspension system of this invention, they will not be described further.

[0027] The biomimetic shock absorption mechanism 3 includes an upper connecting rod 32, a lower connecting rod 33, a gear transmission assembly 31, a first short rod 37, a second short rod 38, a third short rod 39, a horizontal spring 34, a first oblique spring 351, a second oblique spring 352, and an adjusting motor assembly 36. The gear transmission assembly 31 includes a first gear and a second gear that mesh with each other. The first ends of the first short rod 37, the second short rod 38, and the third short rod 39 intersect at a point and are hinged to the drive wheel assembly 2. The second end of the first short rod 37 is fixedly connected to the first gear, the second end of the second short rod 38 is fixedly connected to the second gear, and the second end of the third short rod 39 is hinged to the first end of the lower connecting rod. The second end of the lower connecting rod 33... The first end of the upper link 32 is connected to the first end of the second inclined spring 352, the second end of the second inclined spring 352 is connected to the second gear, the third end of the lower link 33 is connected to the first end of the adjusting motor assembly, the two ends of the horizontal spring 34 are connected to the first gear and the second gear respectively, the first end of the first inclined spring 351 is connected to the first gear, the second end of the first inclined spring 351 is connected to the first end of the upper link 32, the second end of the upper link 32 is connected to the first end of the adjusting motor assembly, and the third end of the upper link 32 and the second end of the adjusting motor assembly are connected to the terrain-adaptive four-bar linkage 1 respectively; the upper link 32 and the lower link 33 form a rigid coupling and their relative positions remain consistent.

[0028] In a specific embodiment, the first short rod 37 is the main force transmission short rod, the second short rod 38 is the secondary force transmission short rod, and the third short rod 39 is the geometric constraint short rod. The main force transmission short rod, the secondary force transmission short rod, and the geometric constraint short rod introduce the vertical load of the wheel end into the lower connecting rod. The main force transmission short rod and the secondary force transmission short rod extend the horizontal spring through the gear set. The geometric constraint short rod is used to maintain the planar motion relationship between the connecting rod and the wheel end structure.

[0029] The upper connecting rod 32 and the lower connecting rod 33 are respectively fixedly connected to a cylindrical gear and mesh with it at a speed ratio of 1:1 through a gear transmission group. The upper connecting rod and the lower connecting rod are rigidly coupled through the gear transmission group. When the wheel end is subjected to an instantaneous impact through the lower connecting rod, the relative position of the upper connecting rod and the lower connecting rod does not change. By changing the geometric position of the contact point of the upper connecting rod and the lower connecting rod on the periphery of the gear, the force and elongation of the horizontal spring and the oblique spring can be adjusted.

[0030] Horizontal spring 34 is arranged laterally along the connecting rod, and two oblique springs are respectively connected to the upper and lower connecting rods at... With the included angle arrangement, when the rotation angle of the upper and lower connecting rods reaches the set threshold, i.e. the preset maximum value, the horizontal spring and the oblique spring jointly participate in the tension. At this time, the mechanical limit block set at the end of the mechanism enters the working area, which makes the system stiffness increase rapidly.

[0031] This mechanism integrates an insect-kangaroo biomimetic model to simulate the compliance of insect joints and multi-stage energy absorption behavior. Three short rods directly connected to the wheel end are designated as the main force transmission rod 37, the secondary force transmission rod 38, and the geometric constraint rod 39. The main force transmission rod 37, secondary force transmission rod 38, and geometric constraint rod 39 introduce the vertical load from the wheel end into the lower connecting rod 33. One end of the main force transmission rod and rod 37, and one end of the secondary force transmission rod 38, are located around the gear periphery; their motion is amplified by the gear set 31 and governs the extension of the spring. The geometric constraint rod 39 maintains the planar motion relationship between the connecting rod and the wheel end structure.

[0032] The upper link 32 and lower link 33 of the biomimetic shock absorber can be designed to a specified length according to the wheel track, suspension travel, and terrain adaptability range. The lower link is hinged to the drive wheel, and the upper link is connected to the terrain-adaptive four-bar linkage, forming the main passive buffer link between the wheel end and the vehicle body.

[0033] like Figure 8 and Figure 9As shown, the main force transmission short rod 37, the secondary force transmission short rod 38, and the geometric constraint short rod 39 transmit the vertical load at the wheel end to the lower connecting rod 33. One end of the main force transmission short rod 37 and the secondary force transmission short rod 38 is located at the periphery of the gear, and its motion is amplified by the gear set 31 and guides the extension of the main spring. The geometric constraint short rod 39 maintains the planar motion relationship between the connecting rod and the wheel end structure. The upper and lower connecting rods are designed according to the vehicle parameters and are respectively hinged to the vehicle body structure and the drive wheel. Each of them is fixedly connected to a cylindrical gear. The transmission group meshes at a 1:1 speed ratio to achieve synchronous angular displacement coupling. The gears can adopt involute or double circular arc tooth profiles to ensure transmission smoothness and meshing accuracy. In the gear meshing synchronization mechanism, the upper and lower connecting rods achieve rigid synchronous coupling through the gear transmission group. When a momentary impact is applied to the wheel end via the lower connecting rod, the rotation of the lower connecting rod is synchronously transmitted to the upper connecting rod via the gear, changing the geometric position of the contact point between the two connecting rods around the gear circumference. This affects the force and elongation of the horizontal spring 34 and the oblique spring 35, thereby precisely adjusting the force state and elongation of the horizontal and oblique springs. The horizontal spring mainly handles small-amplitude disturbances and absorbs energy. The horizontal spring 34 is arranged laterally along the connecting rod, with a small initial installation angle and low equivalent stiffness, mainly used for compliant energy absorption under small displacement disturbances; the oblique spring 35 forms a... The angled arrangement initially involves less participation in displacement, gradually becoming the main load-bearing component as the angular displacement of the connecting rod increases. When the connecting rod angle reaches a set threshold, the two springs stretch synergistically, and the mechanism's limiting block intervenes, forming high-rigidity protection to withstand severe impacts, prevent component damage, and prevent large impacts from being directly transmitted to the transport platform or the main load-bearing rod. The mechanism's operation is divided into three stages to adapt to impacts of different intensities. After the external impact disappears, the restoring force of the spring assembly is transmitted through the connecting rod-gear coupling, pushing the two connecting rods back to their initial positions, achieving automatic reset of the mechanism. In addition, the terrain-adaptive four-bar linkage mechanism, consisting of an upper parallel link, a lower parallel link, and a middle swing rod forming a near-parallelogram structure, combined with this biomimetic shock absorption and buffer mechanism, achieves terrain adaptation and stable operation of the overall mechanism.

[0034] The adjusting motor assembly 36 is only used for initial geometry setting and calibration of the mechanism and does not participate in dynamic control during normal operation. This includes installation angle calibration, spring preload setting, and structural compensation. It does not participate in dynamic attitude control during normal operation and is completely independent of the four active linear motors 101, 102, 103, and 104 in terms of functional path.

[0035] The main working process of the biomimetic shock absorption mechanism 3 is as follows: the vibration of the road surface is transmitted to the gear-spring through three short rods. The main force transmission short rod 37 and the secondary force transmission short rod 38 drive the gear to rotate, and the spring will change accordingly. Through the deformation of the gear-spring and the angle change between the connecting rods, the impact of lunar surface disturbance on the attitude of the carrier platform and the load-bearing rod is reduced. If the disturbance disappears, the deformation can be restored by the elastic force of the spring.

[0036] When minor disturbances occur on the lunar surface, such as when the wheel end contacts a small protrusion, the main force transmission rod 37 and the auxiliary force transmission rod 38 undergo slight displacement, and the gears rotate synchronously, but the overall displacement is small. At this time, the horizontal spring 34 mainly participates in the deformation. The system exhibits low stiffness and compliant characteristics, effectively isolating minor disturbances. When the disturbance increases, the main force transmission rod 37 and the auxiliary force transmission rod 38 generate larger displacements synchronously through the gears, and the effective elongation of the oblique spring 35 increases rapidly and gradually becomes the main energy absorption unit. Due to the geometric amplification effect of the displacement of the main and auxiliary force transmission rods, the elongation of both springs increases nonlinearly, thereby absorbing most of the moderate-intensity impacts. When a large impact or extreme displacement occurs, under severe impact conditions, both springs simultaneously enter a high-load state, causing the system to enter a high-stiffness protection mode to prevent the impact from directly acting on the linear motor, the cattail-like load-bearing rod, and the transport platform. When the external impact disappears, the restoring force of the spring assembly is transmitted through the linkage-gear coupling, causing the contact point of the two linkages to gradually return to the initial position along the periphery of the gear, thus realizing the automatic reset of the mechanism without the need for an active actuator.

[0037] The multi-layered composite main load-bearing rod 4, resembling a cattail, comprises an outer dense epidermal layer, a middle gradient pore structure, and longitudinal bundle nuclei. The middle gradient pore structure, from the outside in, includes an outer small pore region, an intermediate transitional pore region, an inner large pore region, and a central converging pore region. The pore sizes of the outer small pore region and the central converging pore region are smaller than those of the intermediate transitional pore region, and the pore size of the intermediate transitional pore region is smaller than that of the inner large pore region; that is, the pore size changes from small to medium to large to small from the outside in. Three longitudinal bundle nuclei are arranged, with the angle between the centers of any two adjacent longitudinal bundle nuclei being [missing information]. The outer axial direction of the cattail-like multi-layer composite main load-bearing rod 4 is uniformly provided with multiple bamboo-like reinforcing rings, and the middle transition cell pore area is axially staggered with transverse reinforcing cell walls, which are used to constrain the radial deformation of the cell pore structure, transmit transverse shear force, and at the same time disperse the supporting force of the longitudinal bundle nucleus to the entire gradient cell pore layer.

[0038] In practical applications, the cattail-like multi-layer composite main load-bearing rod 4 is the core load-bearing component. It is composed of a dense outer skin layer 41, a gradient cell pore layer, a longitudinal bundle core 43, a transversely reinforcing cell wall 45, and a bamboo-like reinforcing ring 44. All parts are rigidly connected through integrated processing and welding to ensure the stable transmission of dynamic loads under low gravity.

[0039] The dense outer skin layer 41 is made of titanium alloy to form the outer wall of the rod. Its core function is to resist bending and suppress the ellipticization of the rod, so as to avoid the distortion of the rod cross section when the lunar surface is bumpy, and to bear the main bending moment and external load.

[0040] The inner wall of the dense epidermal layer 41 is fitted with a multi-scale gradient pore layer, which is divided into four regions radially: the outer small pore region 421 has a pore diameter of 4-6 mm and a wall thickness of 1.0 mm; the middle transitional pore region 422 has a pore diameter of 6-10 mm and a wall thickness of 0.8 mm; the inner large pore region 423 has a pore diameter of 10-14 mm and a wall thickness of 0.8 mm; and the central converging pore region 424 has a pore diameter of 6-8 mm and a wall thickness of 1.2 mm, providing optimal balance between bending energy absorption and structural stiffness.

[0041] The longitudinal core consists of three titanium alloy strips with a cross-sectional dimension of 6-10mm × 6-10mm. Symmetrically embedded in the cell pore layer and arranged parallel to the axis of the rod, it provides a stable support skeleton, significantly improves the compressive buckling stability, provides axial compressive strength for the load-bearing rod, and prevents local collapse of the inner cavity.

[0042] The transversely reinforced cell wall 45 is the core shear-resistant component of the gradient cell pore layer. The transversely reinforced cell wall 45 can be made of 1.2mm thick TC4 titanium alloy sheets, staggered along the rod axis and laser-welded integrally with the cell wall of the gradient cell pore layer. A notch is pre-reserved in the center of the cell wall to match the longitudinal core; after fitting the core, a secondary welding is performed to achieve a rigid connection between the longitudinal and transverse structures. Its function is to distribute the supporting force of the longitudinal core to the entire gradient cell pore layer, suppress misalignment deformation of the cell pores under transverse shear forces such as the inertial forces during lunar surface equipment turning, starting, and stopping, and simultaneously improve the rod's resistance to high-frequency vibrations.

[0043] Several transverse reinforcing rings 44 are integrated into the interior of the dense epidermal layer 41 at axial intervals of 50-60 mm. The transverse reinforcing rings 44 are dense segments with reduced pore diameters within the epidermal layer. They are integrally formed with the dense epidermal layer 41 and are used to suppress local buckling and elliptic deformation.

[0044] The terrain-adaptive four-bar linkage 1 includes two parallel upper parallel links, two parallel lower parallel links, an upper side rod, a lower side rod, and two intermediate swing rods. The two sides of the terrain-adaptive four-bar linkage 1 have two intermediate swing rods. The two sides of the lower side rod are hinged to the upper link of the biomimetic shock absorption mechanism and the adjusting motor assembly, respectively. The first end and the second section of the cattail-like main load-bearing rod are fixedly connected to the middle position of the two intermediate swing rods, respectively. Specifically, the terrain-adaptive four-bar linkage 1 includes an upper parallel link 11, a lower parallel link 12, and an intermediate swing rod 13, forming a near-parallelogram structure. The lengths of the upper and lower links and the hinge distance between the links of the terrain-adaptive four-bar linkage 1 can be adjusted according to the vehicle body width. In this invention, the deformation of the four-bar linkage under small disturbances is extremely small, and its impact on the transport platform is negligible. When the wheel-end displacement exceeds the compliance range of the bionic damping and buffering mechanism 3, the terrain-adaptive four-bar linkage 1 does not directly bear the small disturbances. Instead, after the bionic damping and buffering mechanism 3 completes its compliance energy absorption function, the geometric adaptability of the terrain-adaptive four-bar linkage 1 gradually becomes significant, and it undertakes the geometric compensation of the main displacements during the disturbance and large disturbance stages in the terrain. At this time, its geometric deformation absorbs large-scale displacements. Through the geometric deformation of both sides, when one side rises, the other side lowers so that the wheel end can still remain in contact with the ground, that is, it can be in contact with the lunar surface.

[0045] The active suspension is symmetrical on both sides, with a total of two suspension units. Each suspension unit is equipped with two linear motors, giving the transport platform 6 four-point active support capability. The active adjustment unit 5 includes a first linear motor 101, a second linear motor 102, a third linear motor 103, and a fourth linear motor 104. Each of the first linear motors 101, 102, 103, and 104 is equipped with a stroke sensor. The first linear motor 101 is equipped with a first stroke sensor 51, the second linear motor 102 with a second stroke sensor 52, the third linear motor 103 with a third stroke sensor 53, and the fourth linear motor 104 with a fourth stroke sensor 54. The body ends of the first linear motors 101, 102, 103, and 104 are connected to the multi-layer composite main load-bearing rod of the imitation cattail. The push rod ends of the first linear motors 101, 102, 103, and 104 are connected to the bottom of the transport platform 6 through ball joints. The tilt angle control and overall height adjustment of the transport platform 6 are achieved through differential or synchronous telescopic movement. The four-linear-motor active adjustment system is arranged with two linear motors on each side. The first linear motor 101, second linear motor 102, third linear motor 103, and fourth linear motor 104 are connected to the four corners of the transport platform, enabling them to act on the four support points of the platform. The motor body is connected to the ball joint of the imitation cattail multi-layer composite main load-bearing rod, and the motor push rod is connected to the bottom support of the transport platform. In a specific embodiment, electromagnetic linear motors are used.

[0046] The control system is located below the transport platform 6. The control system includes a controller and attitude sensors. The attitude sensors are located below the controller, and the linear motor's stroke sensors collect the motor's stroke data and feed it back to the controller. The controller includes an attitude measurement unit (IMU) and a main control unit that calculates the transport platform's tilt angle. The IMU is used to measure the transport platform's tilt angle in real time. With roll rate A stroke sensor located at the bottom of the linear motor is used to measure the displacement of the linear motor's push rod. The main control computing platform is used to actively control four linear motors and perform basic calculations on the motor stroke.

[0047] The suspension system of this invention adopts a cooperative working mode of two-stage passive absorption and three-stage active compensation: The first stage is passive absorption, where only the biomimetic damping mechanism is involved in absorbing energy to cope with minor disturbances: when the wheel end encounters a small degree of unevenness on the lunar surface, the biomimetic damping mechanism 3 absorbs the impact energy. During this stage, the deformation is small, and the attitude change of the transport platform is minimal.

[0048] The second level of passive adaptation involves an adaptive four-bar linkage mechanism further participating on top of the biomimetic shock absorption and buffer mechanism based on the terrain: When the disturbance increases and the deformation of the bionic shock absorption mechanism tends to saturate, the terrain-adaptive four-bar linkage begins to generate geometric deformation, adapting to the larger wheel end displacement through the linkage movement, and maintaining the wheel in contact with the lunar surface.

[0049] The biomimetic damping and adaptive four-bar linkage provide an instantaneous physical response to all terrain disturbances, unaffected by controller mode switching; active control intervention is based entirely on measurable transport platform status indicators.

[0050] The third level of active compensation decision-making involves the active adjustment unit starting to work on the basis of passive control when the disturbance is large, adjusting the attitude of the transport platform.

[0051] Specifically, the controller monitors the tilt angle of the transport platform in real time. ,high Equal states, and calculate the comprehensive disturbance index. Based on the magnitude of the real-time disturbance, it is divided into three working modes: In M0 mode: minor terrain undulations or high-frequency vibrations are primarily absorbed by the biomimetic damping mechanism, while the terrain-adaptive four-bar linkage provides geometric adaptation to ensure wheel-ground contact. Within safe limits, the active system does not output control commands, only monitors the situation, maximizing energy conservation and minimizing actuator wear.

[0052] In M1 mode: When a moderate-intensity disturbance causes the passive system to approach saturation, the transport platform begins to exhibit a tilting tendency exceeding the safety threshold. The active adjustment unit activates, employing a single-sided priority differential strategy to implement rapid differential adjustment on the identified priority-side motor, assisting the passive system in quickly restoring the transport platform to a horizontal position, while limiting the height adjustment amount to avoid excessive intervention.

[0053] In M2 mode: Faced with strong disturbances such as steep slopes and deep pits, the passive system's energy absorption and adaptability are insufficient to maintain the stability of the transport platform. First, during the attitude stabilization phase, differential control is executed at maximum capacity to suppress roll. Second, during the altitude recovery phase, once the roll angle has returned to a safe range, synchronous control is executed to restore the target altitude. In M2 mode, active control undertakes the primary attitude recovery task.

[0054] The active adjustment unit of this invention uses four linear motors as actuators to actively adjust the roll angle and overall height of the transport platform through differential and synchronous control. The suspension structure of this invention does not involve pitch adjustment; therefore, active attitude adjustment only includes two control modes: roll adjustment and height adjustment. Through a hierarchical mechanism combining passive priority and active attitude adjustment compensation, the device of this invention can maintain the roll stability and target height of the transport platform in complex lunar terrain environments, thereby significantly improving the overall mobility and mission reliability.

[0055] Secondly, the present invention provides a control method for an electromagnetic active suspension for lunar surface load-bearing vibration reduction, such as... Figure 10 As shown, it includes the following steps: S0. System initialization and parameter calibration: After the system is powered on, it first performs initialization: Sensor calibration: The IMU is zero-point calibrated, and the four linear motor stroke sensors are zero-point calibrated.

[0056] Parameter loading: Loads a pre-defined set of conservative parameters. This includes sliding mode parameters, grading thresholds, weighting coefficients, etc.

[0057] Neural network initialization: Load the offline-trained neural network model for online parameter scheduling.

[0058] Then, a real-time control cycle is performed. This embodiment takes each control cycle as an example: Status Acquisition and Calculation: Reading the IMU to measure the roll angle of the transport platform in real time With roll rate Read the stroke values ​​from the stroke sensors at the bottom of the four linear motors. .

[0059] Calculate the geometry of the transport platform: ; ; in, , These represent the average travel on the first and second sides, i.e., the left and right sides, respectively, indicating the overall compression or extension of the left / right suspension. The left and right side travel difference characterizes the degree of inconsistency between the compression / extension of the left and right suspensions. The overall height of the transport platform This is the suspension geometry conversion factor, determined by the mechanical structure. This is the initial height offset.

[0060] S1. Define comprehensive indicators First perturbation threshold and the second perturbation threshold ,and ; ; in, All are normalized scaling factors; Assigning weights to each item. The tilt angle of the transport platform. The tilting speed of the transport platform. For the tracking error of the transport platform height, Due to the difference in travel distance between the two sides of the transport platform, This is an estimate of the roll channel disturbance. This represents the height channel disturbance value.

[0061] Disturbance Observation: Estimates of Tilting Channel Disturbance and height channel disturbance value Obtained by running a lumped disturbance observer in the tilt and height channels.

[0062] Tracking error of the transport platform height Obtained through error calculation: , ; in, For tracking error in the tilting channel of the transport platform, The tilt angle of the transport platform is given by the reference value. (level), The required altitude for the current task.

[0063] S2, when When the bionic damping mechanism is used alone or in conjunction with the terrain-adaptive four-bar linkage, it absorbs and adapts to terrain disturbances. At this time, it enters the M0 mode (passive dominant), where the bionic damping mechanism and other passive components such as the terrain-adaptive four-bar linkage absorb the disturbances, while the active control remains inactive or maintains a small amplitude.

[0064] S3, when When the system enters M1 mode (cooperative control), the active adjustment unit is activated. While prioritizing roll suppression, it also considers height, employing a single-sided priority differential strategy to rapidly differentially adjust the identified priority motor. This assists the passive system in quickly restoring the platform's level while limiting height adjustment to avoid excessive intervention. Specifically, the active adjustment unit suppresses roll using a single-sided priority differential strategy by controlling the displacement increment of the linear motor. The specific steps are as follows: S31. Judgment of the significance of lateral tilt.

[0065] S32. Compare the absolute values ​​of the tilt angle of the transport platform. Judgment threshold To determine whether rollover has occurred, when If the tilt is not significant, it is determined that the transport platform has not tilted significantly.

[0066] S33, when If this is the case, it is determined that roll suppression is needed, and single-sided priority differential adjustment is activated. The average travel margin of the first linear motor and the second linear motor on the first side is calculated respectively. Average travel margin of the third and fourth linear motors on the second side ;like If so, the first side is selected as the priority adjustment side; if In this case, the second side is selected as the priority adjustment side, and the instantaneous roll caused by the sudden change in the height of a single wheel is suppressed by the single-side priority differential adjustment.

[0067] Specifically, let the current travel of the four linear motors be... These correspond to the first linear motor on the left front, the second linear motor on the left rear, the third linear motor on the right front, and the fourth linear motor on the right rear, respectively. The travel range of each motor is... Define a single motor. travel margin The minimum distance from the current travel distance to the two extreme positions: ; Calculate the average travel margin for the left side (motors 1 and 2) and the right side (motors 3 and 4) respectively: like Select the left side as the priority adjustment side and set the priority side indicator variable. Otherwise, select the right side as the priority adjustment side and set the priority indicator variable. .

[0068] S4, when Upon entering M2 mode, i.e., active control mode, the system first performs differential control at maximum capacity to suppress roll (attitude stabilization phase). Once the roll angle returns to a safe range, synchronous control is then executed to restore the target height (height recovery phase). In this mode, active control undertakes the primary attitude recovery task. Specifically, the active adjustment unit enters active control mode, prioritizing differential attitude stabilization on both sides. After the platform's attitude stabilizes, synchronous height recovery on both sides is performed, including: S41, Dual-sided differential attitude stabilization: Dual-sided differential adjustment is performed on the linear motors on both sides. The side with priority adjustment follows the logic of mode M1 to quickly suppress the tilt angle of the transport platform to a safe range until the tilt angle meets the requirements. and keep time , The steady-state threshold, This step is similar to step S32, both involving differential adjustment of the left and right sides separately. However, step S32 focuses on quickly suppressing roll while also considering height, whereas step S41 ignores height and focuses entirely on suppressing roll.

[0069] S42. Synchronous Height Recovery on Both Sides: After differential attitude stabilization on both sides, the height error of the transport platform is judged. If... Then, perform bilateral synchronous adjustment until the height error of the transport platform meets the requirements. , The high-security error threshold was used to determine the completion of the high-level recovery phase. Subsequently, the system exited M2 mode and returned to the mode based on comprehensive indicators. The conventional decision-making process.

[0070] Specifically, in steps S3, S41, and S42, the displacement increment of each linear motor is calculated using the following formula: ; in, This is a first-side group level instruction. This is a second-side group level instruction, specifically: ; in, This represents the differential displacement between the two sides. This represents the synchronous displacement on both sides. These are the weighting coefficients. As a priority indicator variable, , This indicates that the first side has priority; Indicates symmetrical differential; The second side takes priority; in step S3, take =1, take in step S41 =0, take in step S42 =1, , This represents the displacement increment of the i-th linear motor. Assign weights to the i-th linear motor based on its travel margin. In step S3... Depending on the calculation priority, the value can be -1, 0, or 1 in step S4. The value can be either -1 or 1 depending on the calculation priority.

[0071] Specifically, differential displacement and synchronous displacement Control quantity output by sliding mode controller , The following mapping relationship was used to calculate: ; in, The control allocation matrix elements are determined based on the dynamic characteristics of the suspension system.

[0072] In this embodiment, the group-level instructions generated by the upper-level controller are... This method safely and efficiently decomposes the displacement commands into four independent linear motors. It employs a three-layer collaborative architecture of "mandatory rule allocation + intelligent QP optimized allocation + dynamic switching" to ensure reliable system operation under various conditions, including normal, high-performance, and fault-degraded scenarios.

[0073] The rule allocation is based on the weight calculation of travel margin to ensure balanced load on the two motors on the same side and prevent a single motor from reaching its travel limit prematurely. This algorithm is simple to calculate and highly reliable, serving as a safety backup strategy for the system.

[0074] For left-side group-level instructions This needs to be assigned to the first linear motor on the left front (subscript 1) and the second linear motor on the left rear (subscript 2). First, calculate the allocation weight of each motor based on the travel margin: ; in, These are the travel margins for the front left and rear left motors, respectively. Weighting satisfy The same applies to the motor on the right.

[0075] Group-level instructions are decomposed into individual motor instructions based on weight: ; Right-side group-level instructions The allocation method is the same: ; in, These are the displacement increments of the first linear motor at the front left, the first linear motor at the rear left, the first linear motor at the front right, and the first linear motor at the rear right, respectively.

[0076] This allocation strategy allows motors with larger travel margins to handle more displacement, naturally avoiding single-motor saturation, and eliminating the need for complex optimization solutions, ensuring that feasible instructions can be generated under any circumstances.

[0077] Under normal circumstances, the above control is executed. However, if computational resources permit during the control process, constrained quadratic programming is used for optimized allocation. This method, while satisfying all physical constraints, simultaneously optimizes energy consumption, actuator protection, and command smoothness, and explicitly integrates motor health status, possessing online fault tolerance capabilities. Specifically, the optimization constraints on the displacement increments of the linear motors on both sides during the control process are as follows: ① The linear motor travel constraint equations are constructed as follows (including health status): in For decision variable vectors This is a diagonal matrix representing the health status of the motors, specifically the health status of the first linear motor, the second linear motor, the third linear motor, and the fourth linear motor. ; express , express When a motor fails ( When ), the corresponding constraint degenerates into Equivalent to coercion Therefore, it was excluded from the allocation.

[0078] ② Construct the rate of change constraint equation: in, No. The displacement increment of the motor in the previous control cycle. No. The maximum allowable rate of change of the motor, For the first Motor displacement increments to avoid actuator impact.

[0079] ③ The instruction matching constraint equations are constructed as follows: This constraint ensures that the total displacement generated by a normally functioning motor meets the group-level command issued by the upper-level controller. If both motors on one side fail, the corresponding group-level command must be zero. Otherwise, the optimization problem remains unsolved, and the system will trigger a higher-level fault degradation strategy.

[0080] ④ Construct the overall control objective function: ; in, To minimize total control energy; To prevent the depletion of penalty items; This is a smoothness penalty term; These are the weighting coefficients; This is the dynamic protection coefficient; For the first The real-time travel margin of the motor; Small positive numbers that prevent division by zero; This is the optimized solution for the previous control cycle.

[0081] The objective function aims to balance minimum energy consumption, actuator protection, and instruction smoothness. The first term... To minimize total control energy and improve system energy efficiency. The second item... To prevent exhaustion of penalty items, allow for travel margin. Small or unfavorable trend in margin change (due to dynamic coefficient) (This is reflected in) applying greater penalties to the motor to achieve preventative protection. (Third item) As a smoothing penalty, it suppresses instruction abrupt changes, improving ride comfort and actuator lifespan.

[0082] These are weighting coefficients, which can be dynamically adjusted by the neural network parameter scheduling module according to the current system mode (M0 / M1 / M2) to achieve dynamic trade-offs between different objectives. It is a dynamic protection factor, which can be adjusted according to the rate of change of the stroke margin. Adjust. When the margin decreases rapidly, increase. To strengthen protection in advance. For the first The real-time travel margin of the motor. To prevent small positive numbers from being divided by zero, such as . This is the optimized solution for the previous control cycle.

[0083] During the control process, an intelligent parameter scheduling module uses a neural network to schedule the parameters of the control process: based on the current system state and mode, the neural network outputs parameter correction amounts. The intelligent parameter scheduling module does not directly output actuator control commands, nor does it participate in the calculation of direct control quantities for the safety closed loop. It only performs slow scheduling of multi-level control parameters. Its design principle is "suggestion rather than enforcement, scheduling rather than takeover," ensuring that the core stability of the system is not affected by fluctuations in the neural network output.

[0084] The scheduling objects cover four main categories: Sliding mode control parameters: Hierarchical decision parameters: , Cooperative allocation parameters: Optimize allocation parameters: , .

[0085] Neural network input and output architecture: Input layer: Observable system state and evaluation metrics Actuator status: , trip margin The trend of stroke change is obtained through filtering and differentiation. Disturbance assessment: Comprehensive indicators Pattern flags: .

[0086] Set of scheduling parameters: .

[0087] Parameter update mechanism: adopts a base value + correction mode. .

[0088] in, A conservative set of parameters that has been thoroughly verified on the ground. This is a bounded correction to the neural network output. This design ensures that even if the neural network output is abnormal, the system can still fall back to a safe, conservative parameter operating point.

[0089] Output correction amount Instead of direct output It is a core security design that ensures the security constraints and update mechanisms for parameters.

[0090] To ensure that neural network scheduling does not compromise system stability, all parameter updates are subject to the following constraints: Parametric physical boundary constraints: ; The upper limit constraint on the rate of change (core safety mechanism) applies to any scheduled parameter. Constrained first-order tracking update is used: ; Discrete implementation: ; in: Suggested values ​​for the parameters output by the neural network. It is a time constant (typically on the order of 0.1-1.0 seconds). This is the maximum allowable rate of change for this parameter. This is the amplitude limiting function.

[0091] Activation strategies for mode-related parameters: The mode is passively dominant: only minor adjustments are needed. The remaining parameters should be kept at their conservative default values. The mode is cooperative control: the focus is on scheduling α, β and sliding mode parameters. The mode is proactive control: comprehensive scheduling with special attention. Coordination.

[0092] Neural network training and update strategies: Offline pre-training: The initial network is trained using supervised learning or reinforcement learning based on simulation data of typical lunar terrain.

[0093] Online incremental learning: During operation, the weights of the neural network output layer are slowly adjusted based on long-term statistics of control performance indicators such as overshoot, settling time, and energy consumption, such as once a day or once per task cycle.

[0094] Experience replay buffer: Stores optimal parameter configurations under typical operating conditions, allowing for quick parameter initialization when similar operating conditions occur.

[0095] Calculation of sliding mode control parameters: Sliding surface Sliding surface .

[0096] Control Law: ; Using a saturation function with a boundary layer Sliding surface parameters: Robustness term gain: Boundary layer thickness: Control coefficient: Nominal model compensation: .

[0097] Simultaneously, a fault tolerance mechanism is configured: A minor fault refers to a fault in only one linear motor on one side: the faulty linear motor corresponds to... Its allocation instruction is forced to zero. The optimization problem automatically redistributes control quantities among the remaining three healthy motors, still able to approximately track the original group-level instructions.

[0098] A severe fault is when both linear motors on one side fail: If both linear motors on one side fail, the group-level command on that side must be zero, and the system will switch to using the motors on the opposite side for limited attitude adjustments, entering a performance degradation mode.

[0099] To balance performance and real-time reliability, the allocation strategy dynamically switches based on system status, forming a three-tiered protection system: QP priority layer, also known as high-performance mode: the default state. When computational resources are sufficient, all motors are healthy, and the QP solver is running normally, the allocation is optimized in the above manner to achieve the best performance.

[0100] Rule fallback layer: Automatically and seamlessly switch to the regular rule assignment described above when any of the following conditions are met: QP solution time exceeds a set threshold, such as 5ms; The main control unit's load rate exceeds a threshold, such as 85%. Numerical solver anomalies were detected, such as iteration non-convergence.

[0101] Average Distribution Layer: In extreme operating conditions, such as severe sensor failure leading to unreliable stroke margin, or failure of regular distribution for any reason, the most conservative average distribution strategy for the motors on the same side is adopted. .

[0102] This strategy completely abandons load balancing, only ensuring that group-level commands are mechanically executed as a safety baseline for maintaining the basic functions of the system.

[0103] The switching process should incorporate appropriate hysteresis to prevent frequent policy jitter near the boundaries. During each switch, the state should be reinitialized with the new policy, as follows: This ensures the continuity of instructions.

[0104] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An electromagnetic active suspension for vibration reduction under lunar surface loads, characterized in that: It includes a transport platform, a control system, and suspension units symmetrically arranged on both sides. Each suspension unit includes a drive wheel assembly, a bionic shock absorption mechanism, a terrain-adaptive four-bar linkage, a cattail-inspired multi-layer composite main load-bearing bar, and an active adjustment unit arranged vertically from bottom to top. The drive wheel assembly is hinged to the bottom of the bionic shock absorption mechanism. The bionic shock absorption mechanism includes an upper connecting rod, a lower connecting rod, a gear transmission assembly, a first short rod, a second short rod, a third short rod, a horizontal spring, a first oblique spring, a second oblique spring, and an adjusting motor assembly. The gear transmission assembly includes a first gear and a second gear that mesh with each other. The first ends of the first, second, and third short rods intersect at a point and are hinged to the drive wheel assembly. The second end of the first short rod is fixedly connected to the first gear, the second end of the second short rod is fixedly connected to the second gear, and the second end of the third short rod is fixedly connected to... The first end of the lower link is hinged, the second end of the lower link is connected to the first end of the second inclined spring, the second end of the second inclined spring is connected to the second gear, the third end of the lower link is connected to the first end of the adjusting motor assembly, the two ends of the horizontal spring are connected to the first gear and the second gear respectively, the first end of the first inclined spring is connected to the first gear, the second end of the first inclined spring is connected to the first end of the upper link, the second end of the upper link is connected to the first end of the adjusting motor assembly, and the third end of the upper link and the second end of the adjusting motor assembly are connected to the terrain-adaptive four-bar linkage respectively. The active adjustment unit includes a first linear motor, a second linear motor, a third linear motor, and a fourth linear motor. Each of the first, second, third, and fourth linear motors is equipped with a stroke sensor. The body ends of the first, second, third, and fourth linear motors are connected to the multi-layer composite main load-bearing rod of the imitation cattail. The push rod ends of the first, second, third, and fourth linear motors are connected to the bottom of the transport platform through ball joints. The tilt angle control and overall height adjustment of the transport platform are realized through differential or synchronous extension and retraction.

2. The electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 1, characterized in that: The multi-layered composite main load-bearing rod, resembling a cattail, comprises an outer dense epidermis, a middle gradient pore structure, and longitudinal bundles of nuclei. The middle gradient pore structure, from the outside in, includes an outer small pore region, an intermediate transitional pore region, an inner large pore region, and a central converging pore region. The pore sizes of the outer small pore region and the central converging pore region are smaller than the pore size of the intermediate transitional pore region, and the pore size of the intermediate transitional pore region is smaller than the pore size of the inner large pore region. Three longitudinal bundles of nuclei are arranged, with an angle between the centers of any two adjacent longitudinal bundles of nuclei. .

3. The electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 2, characterized in that: The outer axial direction of the multi-layer composite main load-bearing rod imitating cattail is uniformly provided with multiple bamboo-joint reinforcing rings, and the middle transition cell pore area is axially staggered with transverse reinforcing cell walls, which are used to constrain the radial deformation of the cell pore structure, transmit transverse shear force, and at the same time disperse the supporting force of the longitudinal bundle nucleus to the entire gradient cell pore layer.

4. The electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 1, characterized in that: The terrain-adaptive four-bar linkage includes two parallel upper parallel links, two parallel lower parallel links, an upper side rod, a lower side rod, and two intermediate swing rods. The two sides of the lower side rod are respectively hinged to the upper link of the bionic shock absorption and buffer mechanism and the adjusting motor assembly. The first end and the second section of the cattail-like main load-bearing rod are respectively fixedly connected to the middle position of the two intermediate swing rods.

5. The electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 1, characterized in that: The control system is located below the transport platform. The control system includes a controller and attitude sensors, with the attitude sensors located below the controller.

6. The electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 1, characterized in that: The first short rod is the main force transmission rod, the second short rod is the secondary force transmission rod, and the third short rod is the geometric constraint rod. The main force transmission rod, the secondary force transmission rod, and the geometric constraint rod introduce the vertical load at the wheel end into the lower connecting rod. The main force transmission rod and the secondary force transmission rod extend the horizontal spring via a gear set. The geometric constraint rod is used to maintain the planar motion relationship between the connecting rod and the wheel end structure. The upper and lower connecting rods are each fixedly connected to a cylindrical gear and mesh with it at a 1:1 speed ratio via a gear transmission set. The upper and lower connecting rods achieve rigid coupling via the gear transmission set. When the wheel end is subjected to an instantaneous impact through the lower connecting rod, the relative positions of the upper and lower connecting rods remain consistent. Changing the geometric position of the contact point between the upper and lower connecting rods at the periphery of the gears can adjust the force and elongation of the horizontal and oblique springs. The horizontal spring is arranged laterally along the connecting rod, and the two oblique springs are respectively connected to the upper and lower connecting rods at... Angle arrangement.

7. A control method for the electromagnetic active suspension for lunar surface load-bearing vibration reduction as described in claim 1, characterized in that: It includes the following steps: S1. Define comprehensive indicators First perturbation threshold and the second perturbation threshold ,and ; ； in, All are normalized scaling factors; Assigning weights to each item. The tilt angle of the transport platform. The tilting speed of the transport platform. For the tracking error of the transport platform height, Due to the difference in travel distance between the two sides of the transport platform, This is an estimate of the roll channel disturbance. This represents the height channel disturbance value; S2, when At that time, the bionic shock absorption and buffer mechanism alone or in combination with the terrain-adaptive four-bar linkage absorbs and adapts to terrain disturbances. S3, when At the same time, the active adjustment unit controls the displacement increment of the linear motor using a single-sided priority differential strategy, prioritizing the suppression of roll while also considering height. The specific steps are as follows: S31. Judgment of the significance of lateral tilt: S32. Compare the absolute values ​​of the tilt angle of the transport platform. Threshold for judging roll angle The relationship between them determines whether tilting has occurred. In this case, it is determined that the transport platform has not tilted. S33, when If this is the case, it is determined that roll suppression is needed, and single-sided priority differential adjustment is activated. The average travel margin of the first linear motor and the second linear motor on the first side is calculated respectively. Average travel margin of the third and fourth linear motors on the second side ;like If so, the first side is selected as the priority adjustment side; if In this case, the second side is selected as the priority adjustment side; S4, when At this time, the active adjustment unit enters the active control mode, prioritizing differential attitude stabilization on both sides. After the attitude of the transport platform stabilizes, synchronous height recovery on both sides is performed, specifically including: S41. Dual-sided differential attitude stabilization: Perform dual-sided differential adjustment on both linear motors as described in step S33 to quickly suppress the tilt angle of the transport platform to a safe range until the tilt angle meets the requirements. ,in For attitude safety threshold, and keep time , The steady-state threshold; S42. Synchronous Height Recovery on Both Sides: After differential attitude stabilization on both sides, the height error of the transport platform is judged. If... Then, perform bilateral synchronous adjustment until the height error of the transport platform meets the requirements. , Once the high safety error threshold is reached, the high-level phase is determined to be complete, and the process returns to step S1.

8. The control method for electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 7, characterized in that: In steps S3, S41, and S42, the displacement increment of each linear motor is calculated using the following formula: ； in, This is a first-side group level instruction. This is a second-side group level instruction, specifically: ； in, This represents the differential displacement between the two sides. This represents the synchronous displacement on both sides. These are the weighting coefficients. As a priority indicator variable, , This indicates that the first side has priority; Indicates symmetrical differential; The second side takes priority; in step S3, take =1, take in step S41 =0, take in step S42 =1, , This represents the displacement increment of the i-th linear motor. Assign weights to the i-th linear motor based on its travel margin.

9. The control method for electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 8, characterized in that: Differential displacement on both sides and synchronous displacement on both sides Control quantity output by sliding mode controller , The following mapping relationship was used to calculate: ； in, The control allocation matrix elements are determined based on the dynamic characteristics of the suspension system.

10. The control method for electromagnetic active suspension for lunar surface load-bearing vibration reduction according to claim 9, characterized in that: In step S3, when the computational load allows, the displacement increments of the linear motors on both sides are optimized and constrained during the control process: The linear motor travel constraint equations are constructed as follows: ； in, A vector of decision variables; This is the diagonal matrix representing the motor's health status. The health statuses of the first linear motor, the second linear motor, the third linear motor, and the fourth linear motor are respectively. Construct the rate of change constraint equation: in, For the first The displacement increment of the motor in the previous control cycle. For the first The maximum allowable rate of change of the motor, For the first Motor displacement increment; The instruction matching constraint equations are constructed as follows: Construct the overall control objective function for the control system: ； in, To minimize total control energy; To prevent the depletion of penalty items; This is a smoothness penalty term; These are the weighting coefficients; This is the dynamic protection coefficient; For the first Real-time travel margin of the linear motor; To prevent small positive numbers from being divided by zero; This is the optimized solution for the previous control cycle.

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