Rheological analysis method for walking subsidence of seabed crawler-type ore collecting vehicle
By constructing a viscoelastic deformation model and using intelligent inversion methods, the problem of analyzing the creep characteristics of ore collection truck subsidence under deep-sea soft bottom was solved, enabling accurate prediction and safety assessment of ore collection truck subsidence and ensuring the stability of deep-sea mining operations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-22
- Publication Date
- 2026-03-24
AI Technical Summary
Existing technologies are insufficient to accurately analyze and predict the subsidence and creep characteristics of tracked mining vehicles on the seabed in soft, sparse seabeds, which affects the continuity and safety of mining operations.
The rheological theory analysis method of the subsidence of tracked mining trucks on the seabed was adopted. By constructing a viscoelastic deformation model, the viscoelastic deformation formula of each point on the surface of the sparse and soft bottom soil layer was derived by using the Laplace spatial differential operator and Laplace transform, combined with the Burgers model and the five-element generalized Kelvin model. KNN and genetic algorithm were used for intelligent inversion to optimize the model parameters.
It can accurately calculate the creep variables of ore collection vehicles during travel, providing condition assessments in engineering practice and ensuring the safety and continuity of mining operations.
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Figure CN116840041B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the fields of geotechnical engineering and deep-sea mining, specifically relating to a rheological analysis method for the subsidence of a tracked ore collection vehicle traveling on the seabed. Background Technology
[0002] Research on deep-sea mineral resource extraction technology in my country has largely focused on polymetallic nodule minerals, primarily employing ore collection vehicles to cut, crush, and collect the ore on the seabed. As a core component of deep-sea mining systems, these ore collection vehicles must move stably on soft, sparse seabed surfaces to ensure the continuity and safety of mining operations.
[0003] Deep-sea soft bottoms possess mechanical properties such as porosity, high water content, and low shear strength. Mining trucks weighing several tons traversing these high-pressure surfaces are prone to subsidence and slippage over time. To ensure the normal and continuous operation of deep-sea mining systems, it is essential to study the rheological properties of deep-sea soft bottoms. Creep, a type of rheology, has a significant impact on the long-term stability and safety of practical engineering projects.
[0004] Previous studies have mainly employed three methods: in-situ testing, collecting samples from seabed sediments for field or laboratory testing, and using simulated soil. However, sampling deep-sea soft and sparse bottom soils is difficult and cannot meet the requirements for large-scale experiments. Furthermore, none of the above three methods consider the unique and important rheological properties of deep-sea soft and sparse bottom soils.
[0005] Therefore, this invention provides a rheological analysis method for the subsidence of a tracked ore collection vehicle traveling on the seabed. Based on the analytical analysis of the viscoelastic deformation of rock mass, this method constructs a rheological mechanical model of the creep of deep-sea soft seabed subsidence during the ore collection vehicle's movement. It then performs viscoelastic deformation analysis of the soft seabed under the tracks of the ore collection vehicle under uniformly distributed loads, deriving creep formulas for various points on the surface of the soft seabed under the tracks. This method is expected to provide theoretical guidance for the analysis of creep in subsidence caused by ore collection vehicles traveling on the seabed.
[0006] The current research status of domestic studies on the creep characteristics of mining trucks during travel and subsidence is as follows:
[0007] 1. The article "Experimental Study on Triaxial Compression Creep Model of Simulated Soil in Deep-Sea Sparse and Soft Bodies" obtained the creep curves of the simulated soil under the same confining pressure and different axial pressures through consolidated drained triaxial compression creep tests. Different rheological models were used to identify the parameters of the creep curves to determine the compression creep constitutive model of the simulated soil. However, this study, based on consolidated drained triaxial compression creep tests, showed that the parameters obtained by fitting the creep constitutive equation to the experimental curves differed significantly from the actual situation. (See *Journal of Central South University (Natural Science Edition)*, 2014, Vol. 12, Authors: Ma Wenbo, et al.);
[0008] 2. The article "Research Progress on Characteristics of Deep-Sea Sparse and Soft Bodies and the Walking Performance of Mining Vehicles" established the uniaxial compression, triaxial compression, and direct shear rheological constitutive equations for simulated deep-sea soil using the GDS triaxial creep tester and a self-developed compression-shear creep test device. The dynamic indentation creep curves of the simulated deep-sea soil were also measured using a dynamic indentation creep test device. However, further research is needed on the dynamic rheological characteristics of deep-sea sparse and soft bottom materials, specifically considering the operating modes of mining vehicles. (See *Chinese Journal of Nonferrous Metals*, 2021, Vol. 10, Authors: Rao Qiuhua, et al.) Summary of the Invention
[0009] To overcome the shortcomings of the existing technology, this invention provides a rheological analysis method for the subsidence of a tracked mining vehicle traveling on the seabed.
[0010] To achieve the above objectives, the present invention adopts the following technical solution:
[0011] The rheological analysis method for the subsidence of a tracked ore-collecting vehicle on the seabed is as follows:
[0012] (1) Conduct mechanical analysis of the subsidence and creep of the deep-sea soft bottom layer during the movement of the tracked mining truck. The load of the mining truck is applied to the deep-sea soft bottom layer through the track.
[0013] (2) The displacement analysis of the subsidence creep of the deep-sea soft bottom during the movement of the tracked mining truck was carried out using the corner point method.
[0014] (3) By using the differential operator in the Laplace space and performing the Laplace transformation on it, the general solution of viscoelasticity of the soft bottom soil layer under the double-sided track is obtained.
[0015] (4) The formula for calculating the viscoelastic deformation of each point on the surface of the soft rock and soil layer under the double-sided track is derived. If the soft rock and soil exhibits unstable creep characteristics, the Burgers model is adopted; if the soft rock and soil exhibits stable creep characteristics, the five-element generalized Kelvin model is adopted.
[0016] (5) Perform the inversion of mechanical parameters in the established viscoelastic model. Instantaneous parameters are obtained directly from analytical formulas. Other viscoelastic parameters are obtained by intelligent inversion method combining KNN and genetic algorithm. The individuals corresponding to the error function are divided into populations, and the population is updated through crossover and mutation until the optimal value is obtained.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] 1. This invention comprehensively considers the subsidence and creep characteristics of deep-sea soft bottom sediments, and can calculate the subsidence creep of the mining truck. By combining the monitoring data in actual engineering and conducting comparative analysis, the working status of the mining truck can be evaluated more accurately, providing a basis for the subsidence prediction and safety assessment of deep-sea mining trucks.
[0019] 2. This invention method can be widely applied to the study of creep characteristics in fields such as civil engineering, hydropower, mining, and energy, and has a wide range of applications. Attached Figure Description
[0020] Figure 1 A schematic diagram of the rheological analysis method for the submersion of a tracked mining truck on the seabed;
[0021] Figure 2 A schematic diagram of a semi-infinite body boundary subjected to a concentrated normal force;
[0022] Figure 3 This is a schematic diagram of displacement analysis of the corner points of the mining car tracks;
[0023] Figure 4 A schematic diagram of the Burgers' mechanical model;
[0024] Figure 5 A schematic diagram of the five-element generalized Kelvin model;
[0025] Figure 6 A roadmap for inverse analysis of viscoelastic parameters;
[0026] Figure 7 For viscoelastic parameter back analysis techniques based on P cro Cross diagram;
[0027] Figure 8 This is a schematic diagram of the transposition variation of viscoelastic parameters using inverse analysis techniques. Detailed Implementation
[0028] like Figure 1 As shown, the rheological analysis method for the subsidence of a tracked ore-collecting vehicle on the seabed is as follows:
[0029] 1. Conduct a mechanical analysis of the subsidence and creep of the deep-sea soft bottom layer during the movement of the tracked ore collection vehicle. The load of the ore collection vehicle is applied to the deep-sea soft bottom layer through the tracks. The specific method is as follows:
[0030] The load of the ore-collecting car acts on the deep-sea soft rock and soil layer through the tracks on both sides of the ore-collecting car. The load of the ore-collecting car is simplified to a concentrated force, and the vertical displacement of any point in the deep-sea soft rock and soil layer under the tracks of the ore-collecting car is analyzed, such as... Figure 2 The vertical displacement of any point deep in the dilute soft substrate caused by a concentrated force P on the boundary of a semi-infinite elastic body is:
[0031]
[0032] In the formula: E is the elastic modulus of the deep-sea soft bottom rock and soil layer; μ is the Poisson's ratio of the rock and soil layer; z is the vertical depth of the measuring point; R is the distance from the concentrated force to the measuring point;
[0033] Under the load of a mining truck, the surface of a deep-sea soft bottom layer is subjected to uniformly distributed pressure but exhibits non-uniform vertical displacement. The uniformly distributed load on the soft bottom surface is then calculated.
[0034]
[0035] In the formula: P is the total pressure exerted by the ore collection vehicle load on the deep-sea soft bottom rock and soil layer, and A is the area of the ore collection vehicle track;
[0036] 2. The corner point method was used to analyze the displacement of deep-sea soft bottom sediment subsidence creep during the movement of the tracked ore collection vehicle. The specific method is as follows:
[0037] like Figure 3 Let point B on the soft substrate surface under the track be a corner point with coordinates (a, b). Within the load range, take a differential element at coordinates (x1, y1) with area dA = dx1dy1, and the distance from the corner point is:
[0038]
[0039] The vertical displacement of the soft substrate surface at the corner point is:
[0040]
[0041] Perform coordinate transformation on equation (3) to obtain m = a - x1 and n = b - y1, and then introduce the inverse function of the hyperbola sine function. The vertical displacement of the deep-sea soft bottom rock and soil layer at the apex of the straight edge of the mining car track is obtained:
[0042]
[0043] The vertical displacement of the soft bottom surface at any point N on the outer axis of symmetry of the mine car track, at a distance x from the center point, can be obtained by superimposing the formula for the vertical displacement of the rock and soil surface below the corner point:
[0044]
[0045] The vertical displacement of the rock surface below the midpoint of the straight side of the rectangular bearing pad is obtained by substituting x = a into equation (5):
[0046]
[0047] 3. By using differential operators in Laplace space and performing a Laplace transform on them, the general viscoelastic solution for the sparse and soft bottom soil layer under the double-sided track is derived. The specific method is as follows:
[0048] The three-dimensional viscoelastic differential constitutive relation in Laplace space can be expressed as:
[0049]
[0050]
[0051] In the formula: All are differential operators in Laplace space;
[0052] In three-dimensional space, the relationships between elastic modulus E, Poisson's ratio μ, elastic shear modulus G, and elastic bulk modulus K are as follows:
[0053]
[0054]
[0055] Performing a Laplace transform on equation (10), i.e., using q0, G, Substituting K, we obtain the general solution for viscoelastic displacement in Lagrange space:
[0056]
[0057] 4. The formula for calculating the viscoelastic deformation at various points on the surface of the soft soil and rock layer under the double-sided tracks is derived. If the soft soil and rock layer exhibits unstable creep characteristics, the Burgers model is used; if the soft soil and rock layer exhibits stable creep characteristics, the five-element generalized Kelvin model is used. The specific method is as follows:
[0058] 1) If the soft, sparse-bed soil exhibits unstable creep characteristics, the Burgers model is used, and its mechanical model is as follows: Figure 4 As shown;
[0059] Its creep constitutive equation is:
[0060]
[0061] The differential operator is:
[0062]
[0063] The parameters are as follows:
[0064]
[0065] After inverse Laplace transform, the formula for calculating the viscoelastic deformation ω(t) of the sparse and soft substrate at the center point under the double-sided tracks, based on the Burgers model, is obtained:
[0066]
[0067] in:
[0068]
[0069] 2) If the soft, sparse-bedded soil exhibits stable creep characteristics, then the five-element generalized Kelvin model is adopted, and its mechanical model is as follows: Figure 5 As shown;
[0070] Its creep constitutive equation is:
[0071]
[0072] The differential operator is:
[0073]
[0074] For convenience, let:
[0075]
[0076] Where: G0 is the elastic shear modulus of the deep-sea soft bottom rock and soil layer, MPa; G1 and G2 are the viscoelastic shear moduli of the deep-sea soft bottom rock and soil layer, MPa; K is the bulk modulus, MPa; η1 and η2 are the viscosity coefficients, MPa; p0~p2, q1~q2, P1 ′ ~P7 ′ To facilitate the representation of the introduced variables;
[0077] Substituting equations (18) to (19) into equation (11), and through inverse Laplace transform, we can obtain the formula for calculating the viscoelastic deformation ω(t) of the sparsely soft substrate at the center point of the double-sided track based on the five-element generalized Kelvin model:
[0078]
[0079]
[0080]
[0081] ω(t)=ω1(t)+ω2(t) (22) The parameters A and B in equation (22) are taken as follows for the center point of the surface, the edge point of the surface, and the center point of the deep sea soft bottom rock and soil layer:
[0082] ① The center point of the surface of the deep-sea soft bottom rock and soil layer: A = 2q0R0, B = 0;
[0083] ② Edge points on the surface of deep-sea soft bottom rock and soil layers: B = 0;
[0084] ③Deep center point of the soft, sparse-bottomed rock and soil layer in the deep sea:
[0085] 5. Invert the mechanical parameters in the established viscoelastic model. Instantaneous parameters are obtained directly from analytical formulas; other viscoelastic parameters are obtained using an intelligent inversion method combining KNN and genetic algorithms. Individuals corresponding to the error function are divided into populations, and the population is updated through selection, crossover, and mutation until the optimal value is obtained. The specific method is as follows:
[0086] 1) Instantaneous parameters such as instantaneous elastic modulus E0, elastic shear modulus G0, and elastic bulk modulus K are directly obtained using the following formulas:
[0087]
[0088]
[0089]
[0090] 2) Other viscoelastic parameters, such as η1, η2, and G1, are obtained using an intelligent inversion method combining KNN and genetic algorithms, such as... Figure 6 ;
[0091] Based on the genetic algorithm, the parameters to be inverted are set as a genetic population. Each individual in the population represents a possible solution to the problem. The degree to which an individual adapts to the environment is represented by an error function. Individuals with poor fitness are eliminated, while individuals with good fitness continue to reproduce. The reproduction process involves selection, crossover, and mutation to form a new population until the optimal solution is obtained. The main steps are as follows:
[0092] ① Encoding: The candidate solutions of the inversion parameters are represented by chromosomes, and each individual is represented by a gene. Using binary encoding, they are transformed into chromosomes composed of genes in a certain structure, realizing the mapping process from the solution space to the encoding space;
[0093] ② Initialize the population: Initialize the mechanical parameters in the viscoelastic model according to the set conditions, set the maximum number of iterations N, and set the crossover rate P based on multiple experiments or empirical values. cro Variation rate P mut1 P mut2 P mut ;
[0094] ③ Calculate the individual error function (fitness): Based on the previously determined formula (23) for calculating the viscoelastic deformation ω(t) of the soft bottom at the center point of the double-sided track, calculate the error function:
[0095]
[0096] Where: n is the number of measured displacements; (ω i (X, t i ) is the calculated deformation value at time t obtained from the calculation formula of the viscoelastic deformation ω(t) of the soft bottom material under the center point of the double-track; ω i is the measured deformation value at time t; obtain the maximum fitness value F max , the minimum value F min , and the average value F avg ;
[0097] ④ Calculate the average fitness of each part of the population: Based on the KNN algorithm, divide the population into three parts, X1, X2, X3:
[0098] Find the individuals corresponding to the maximum fitness value F max , the minimum value F min , and the average value F avg respectively, x = [x1, x2, x3,..., x n , by calculating the distance between individuals and other individuals:
[0099]
[0100] Those with close distances are grouped into one group, and the probability of each individual being selected is:
[0101]
[0102] Obtain the average fitness values F1, F2, and F3 of each part of the population;
[0103] ⑤ Evolution calculation: Update the population through individual selection, crossover, and mutation; assume F1 < F2 < F3, if the fitness is F1, perform selection based on individual fitness, perform crossover based on P cro (such as Figure 7 ), perform mutation based on P mut1 ; if the fitness is F2, perform mutation based on P mut2 ; if the fitness is F3, perform mutation based on P mut3 (such as Figure 8 );
[0104] Update the population according to the above results until the maximum number of iterations is reached, and output the optimal solution of the mechanical parameters in the viscoelastic model.
Claims
1. A rheological analysis method for the subsidence of a tracked mining vehicle traveling on the seabed, characterized in that, The steps are as follows: (1) Conduct mechanical analysis of the subsidence and creep of the deep-sea soft bottom layer during the movement of the tracked mining truck. The load of the mining truck is applied to the deep-sea soft bottom layer through the track. (2) The displacement analysis of the subsidence creep of the deep-sea soft bottom during the movement of the tracked mining truck was carried out using the corner point method. (3) By using the differential operator in the Laplace space and performing the Laplace transformation on it, the general solution of viscoelasticity of the soft bottom soil layer under the double-sided track is obtained. (4) The formula for calculating the viscoelastic deformation of each point on the surface of the soft rock and soil layer under the double-sided track is derived. If the soft rock and soil exhibits unstable creep characteristics, the Burgers model is adopted; if the soft rock and soil exhibits stable creep characteristics, the five-element generalized Kelvin model is adopted. (5) Perform the inversion of mechanical parameters in the established viscoelastic model. Instantaneous parameters are obtained directly from analytical formulas. Other viscoelastic parameters are obtained by intelligent inversion method combining KNN and genetic algorithm. The individuals corresponding to the error function are divided into populations, and the population is updated through crossover and mutation until the optimal value is obtained.
2. The rheological analysis method for the subsidence of a tracked ore-collecting vehicle on the seabed according to claim 1, characterized in that, A mechanical analysis was conducted on the subsidence and creep of a tracked ore collection vehicle in the deep sea during its movement. The load of the ore collection vehicle was applied to the deep-sea soft rock and soil layer through the tracks. The specific method is as follows: The load of the ore-collecting car acts on the deep-sea soft rock and soil layer through the tracks on both sides of the ore-collecting car. The load of the ore-collecting car is simplified to a concentrated force. The vertical displacement at any point in the deep-sea soft rock and soil layer under the tracks of the ore-collecting car is analyzed, and the concentrated force acts on the boundary of the semi-infinite elastic body. The resulting vertical displacement at any point in the deep, soft sediment is: In the formula: The elastic modulus of the soft, sparse-bottomed rock and soil layer in the deep sea; The Poisson's ratio of the soil and rock layers; The vertical depth of the measuring point; The distance from the concentrated force to the measuring point; Under the load of a mining truck, the surface of a deep-sea soft bottom layer is subjected to uniformly distributed pressure but exhibits non-uniform vertical displacement. The uniformly distributed load on the soft bottom surface is then calculated. In the formula: The total pressure exerted on the soft, sparse rock and soil layer of the deep sea by the load of the mining truck. The area of the mining car track.
3. The rheological analysis method for the subsidence of a tracked ore-collecting vehicle on the seabed according to claim 1, characterized in that, The corner point method was used to analyze the displacement of deep-sea soft bottom sediment subsidence creep during the movement of a tracked ore-collecting vehicle. The specific method is as follows: Let the coordinates of point B on the soft substrate surface under the track be... The corner point, within the load range, has coordinates of ( , Take a differential unit at point ) with an area of The distance from the corner point is: ; The vertical displacement of the soft substrate surface at the corner point is: In the formula: The elastic modulus of the soft, sparse-bottomed rock and soil layer in the deep sea; The Poisson's ratio of the soil and rock layers; Uniformly distributed load borne by a soft substrate surface; Perform a coordinate transformation on equation (3) , Then, we introduce the inverse function of the hyperbola sine function. The vertical displacement of the deep-sea soft bottom rock and soil layer at the apex of the straight edge of the mining car track is obtained: The distance from the center point on the outer axis of symmetry of the mine car track is The vertical displacement of the soft substrate surface at any point N can be obtained by superimposing the formulas for the vertical displacement of the soil surface below the corner point: The vertical displacement of the rectangular track's straight side midpoint on the soft substrate surface will Substituting into equation (5), we get:
4. The rheological analysis method for the subsidence of a tracked ore-collecting vehicle on the seabed according to claim 3, characterized in that, By using differential operators in Laplace space and applying a Laplace transform, the general viscoelastic solution for the sparse and soft bottom soil layer under the double-sided track is derived. The specific method is as follows: The three-dimensional viscoelastic differential constitutive relation in Laplace space can be expressed as: In the formula: , , , All are differential operators in Laplace space; , , , These are the deviatoric stress tensor, deviatoric strain tensor, spherical stress tensor, and spherical strain tensor in Laplace space, respectively. In three-dimensional space, elastic modulus Poisson's ratio Elastic shear modulus Elastic bulk modulus The relationship between them is: Equation (6) is expressed as: Performing a Laplace transform on equation (10), i.e., using , generation , generation The general solution for viscoelastic displacement in Lagrange space: are the variables of the Laplace transform.
5. The rheological analysis method for the subsidence of a tracked ore-collecting vehicle on the seabed according to claim 4, characterized in that, The formula for calculating the viscoelastic deformation at various points on the surface of the soft soil and rock layer under the double-sided tracks was derived. If the soft soil and rock layer exhibits unstable creep characteristics, the Burgers model is used; if the soft soil and rock layer exhibits stable creep characteristics, the five-element generalized Kelvin model is used. The specific method is as follows: 1) If the soft, sparse soil exhibits unstable creep characteristics, then the Burgers model should be used; Its creep constitutive equation is: The differential operator is: In the formula, , , For stress, the first derivative of stress, and the second derivative of stress; , For strain, the first derivative of strain, and the second derivative of strain; , , For the viscoelastic parameters of soft, sparse-bedded soil and rock; , The viscoelastic shear modulus of soft, sparsely packed soil and rock. The parameters in formula (13) are: After inverse Laplace transform, the viscoelastic deformation of the thin, soft substrate at the center point under the double-sided tracks is obtained based on the Burgers model. Calculation formula: in: 2) If the soft, sparse soil exhibits stable creep characteristics, then the five-element generalized Kelvin model is adopted; Its creep constitutive equation is: The differential operator is: For convenience, let: In the formula: The elastic shear modulus of the soft, sparse-bottomed rock and soil layer in the deep sea, in MPa; , is the viscoelastic shear modulus of the deep-sea soft bottom rock and soil layer, MPa; K is the bulk modulus, MPa; , The viscosity coefficient; , , For ease of representation, the introduced variables are shown; t represents time. Formula (18) (19) Substituting into equation (11) and using the inverse Laplace transform, we can obtain the viscoelastic deformation of the thin, soft substrate at the center point of the double-sided track based on the five-element generalized Kelvin model. Calculation formula: The parameters A and B in equation (22) are taken as follows for the center point of the surface, the edge point of the surface, and the center point of the deep sea soft bottom rock and soil layer: Center point of the surface of the soft, sparse-bottomed rock and soil layer in the deep sea: , ; Edge points of the surface of deep-sea soft bottom rock and soil layer: , ; Deep center point of the soft, sparse-bottomed rock and soil layer in the deep sea: ; In the formula, Uniformly distributed load borne by a soft substrate surface; The vertical depth of the measuring point; The distance from the concentrated force to the measuring point.
6. The rheological analysis method for the subsidence of a tracked ore-collecting vehicle on the seabed according to claim 1, characterized in that, The mechanical parameters in the established viscoelastic model are inverted. Instantaneous parameters are obtained directly from analytical formulas; other viscoelastic parameters are obtained using an intelligent inversion method combining KNN and genetic algorithms. Individuals corresponding to the error function are divided into populations, and the population is updated through selection, crossover, and mutation until the optimal value is obtained. The specific method is as follows: 1) Instantaneous elastic modulus Elastic shear modulus The bulk modulus K is obtained directly using the following formula: In the formula, Uniformly distributed load borne by a soft substrate surface; The Poisson's ratio of the soil and rock layers; The vertical depth of the measuring point; The distance from the concentrated force to the measuring point; 2) Other viscoelastic parameters: , , The result was obtained using an intelligent inversion method combining KNN and genetic algorithms. Based on the genetic algorithm, the parameters to be inverted are set as a genetic population. Each individual in the population represents a possible solution to the problem. The degree to which an individual adapts to the environment is represented by an error function. Individuals with poor fitness are eliminated, while individuals with good fitness continue to reproduce. The reproduction process involves selection, crossover, and mutation to form a new population until the optimal solution is obtained. The main steps are as follows: Encoding: The candidate solutions of the inversion parameters are represented by chromosomes, and each individual is represented by a gene. Using binary encoding, they are transformed into chromosomes composed of genes in a certain structure, realizing the mapping process from the solution space to the encoding space. Population initialization: Initialize the mechanical parameters in the viscoelastic model according to the set conditions, set the maximum number of iterations N, and set the crossover rate based on multiple experiments or empirical values. Variation rate , , ; Calculate the individual error function: based on the previously determined viscoelastic deformation of the soft bottom material at the center point under both tracks. Calculation formula (23), calculation of error function: In the formula: These are the measured displacements; To determine the viscoelastic deformation of the soft bottom material at the center point under both tracks Obtained by the calculation formula Calculate the deformation value at time; for Measured deformation value at time; obtain maximum fitness value. Minimum value ,average value ; Calculate the average fitness of each part of the population: Based on the KNN algorithm, the population is divided into three parts. , , : Find the maximum fitness value respectively Minimum value ,average value The corresponding individuals, By calculating the distance between individuals: Those that are close in distance are grouped together, and the probability of each individual being selected is: The average fitness of each part of the population , , ; Evolutionary computation: updating the population through individual selection, crossover, and mutation; assuming... If fitness is Selection is based on individual fitness, based on Perform crossover, based on Perform mutation; if fitness is ,based on Perform mutation; if fitness is ,based on To undergo mutation; The population is updated based on the above results until the maximum number of iterations is reached, and the optimal solution of the mechanical parameters in the viscoelastic model is output.