Soil parameter analysis method, device, equipment and medium based on foot end stress

Abstract

The present application relates to the technical field of soil analysis, in particular to a soil parameter analysis method, device, equipment and medium based on foot end stress. The robot is placed on the soil, and the foot end of the robot will sink into the soil during walking. Different sinking depths of the foot end will be subjected to different normal stresses and shear stresses applied by the soil to the foot end. That is, the normal stress and shear stress are related to the sinking depth. By adjusting the sinking depth to obtain multiple sets of normal stress and shear stress, linear fitting is performed on the multiple sets of normal stress and shear stress to obtain a linear equation related to the normal stress and shear stress. Based on the coefficient of the linear equation, the soil parameters are obtained, and the soil parameters are sent to a remote terminal for soil data analysis. Since the robot can be remotely controlled to walk on the soil, and the normal stress and shear stress can be directly collected by the sensor without sampling the soil on site, the application range of the soil analysis is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil analysis, in particular to a soil parameter analysis method, device, equipment and medium based on foot end stress. BACKGROUND

[0002] Through analyzing soil parameters, the bearing capacity of soil can be known. The prior art brings soil back to the laboratory through on-site sampling, which is limited by the number of samples that can be sampled, thereby reducing the application range of soil analysis.

[0003] In summary, the existing soil parameter analysis method has a small application range due to the limitation of the number of samples.

[0004] Therefore, the prior art still needs to be improved and improved. SUMMARY

[0005] To solve the above technical problems, the present application provides a soil parameter analysis method, device, equipment and medium based on foot end stress, which solves the problem that the existing soil parameter analysis method has a small application range due to the limitation of the number of samples.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a soil parameter analysis method based on foot end stress, which comprises:

[0008] The stress data applied by the soil to the robot foot end is collected by the sensor, the number of stress data is several groups, each group of stress data includes a normal stress value and a shear stress value corresponding to each settlement depth, and the shear stress value is the peak shear stress value received by the robot foot end;

[0009] Linear fitting is performed on each group of normal stress values and shear stress values to obtain a linear equation;

[0010] Based on the coefficients of the linear equation, the soil parameters are obtained, which are sent to a remote terminal for soil data analysis.

[0011] In an implementation mode, linear fitting is performed on each group of normal stress values and shear stress values to obtain a linear equation, which comprises:

[0012] The least square method is used to linearly fit each group of normal stress values and shear stress values to obtain a linear equation.

[0013] In an implementation mode, based on the coefficients of the linear equation, the soil parameters are obtained, which comprises:

[0014] Based on the coefficients of the linear equation, the soil parameters involved in the Mohr-Coulomb criterion are obtained.

[0015] In one implementation, based on the coefficients of the linear equation, the soil parameters involved in the Mohr-Coulomb criterion are obtained, including:

[0016] Determining the constant term coefficient and the linear term coefficient in the coefficients;

[0017] Taking the value of the constant term coefficient as the cohesion of the soil;

[0018] Taking the arctangent value of the linear term coefficient as the internal friction angle of the soil, and taking the cohesion and the internal friction angle as the soil parameters involved in the Mohr-Coulomb criterion.

[0019] In one implementation, the method is applied to solve the normal stress resultant value and the shear stress resultant value of the soil applied to the robot foot end sunken in the soil.

[0020] In one implementation, the part of the robot foot end sunken in the soil is less than half of the robot foot end; solving the normal stress resultant value and the shear stress resultant value of the soil applied to the robot foot end sunken in the soil includes:

[0021] Obtaining the radius of the robot foot end and the maximum sunken depth corresponding to the foot end bottom;

[0022] Based on the radius, the maximum sunken depth, and the soil parameters, stress analysis is performed on each point on the foot end to determine the normal stress resultant value and the shear stress resultant value.

[0023] In one implementation, the part of the robot foot end sunken in the soil is greater than half of the robot foot end; solving the normal stress resultant value and the shear stress resultant value of the soil applied to the robot foot end sunken in the soil includes:

[0024] Obtaining the radius of the robot foot end and the maximum sunken depth corresponding to the foot end bottom and the sunken depth of the foot end center from the soil surface;

[0025] Based on the radius, the maximum sunken depth, and the sunken depth of the foot end center from the soil surface, and the soil parameters, stress analysis is performed on each point on the foot end to determine the normal stress resultant value and the shear stress resultant value.

[0026] In the second aspect, the embodiments of the present application further provide a soil parameter analysis device based on foot end stress, wherein the device includes the following components:

[0027] The data acquisition module is configured to acquire stress data of soil applied to the foot end of the robot through the sensor, wherein the stress data is in a plurality of groups, each group of the stress data comprises normal stress values and shear stress values corresponding to each sinking depth, and the shear stress values are peak shear stress values applied to the foot end of the robot.

[0028] The linear fitting module is configured to perform linear fitting on the normal stress values and the shear stress values in each group to obtain a linear equation.

[0029] The data analysis module is configured to obtain soil parameters based on coefficients of the linear equation, and the soil parameters are sent to a remote terminal for soil data analysis.

[0030] In a third aspect, an embodiment of the present application further provides a terminal device, wherein the terminal device comprises a memory, a processor, and a soil parameter analysis program based on foot end stress stored in the memory and executable on the processor, and the processor implements steps of the soil parameter analysis method based on foot end stress when executing the soil parameter analysis program based on foot end stress.

[0031] In a fourth aspect, an embodiment of the present application further provides a computer readable storage medium, wherein the computer readable storage medium stores a soil parameter analysis program based on foot end stress, and the processor implements steps of the soil parameter analysis method based on foot end stress when executing the soil parameter analysis program based on foot end stress.

[0032] Beneficial effects: the robot is placed on the soil, and the foot end of the robot sinks into the soil during walking, and the foot end sinks to different depths and receives different normal stress and shear stress applied by the soil, that is, the normal stress and shear stress are related to the sinking depth, a plurality of groups of normal stress and shear stress are obtained by adjusting the sinking depth, linear fitting is performed on the plurality of groups of normal stress and shear stress to obtain a linear equation of the normal stress and shear stress, soil parameters are obtained based on coefficients of the linear equation, and the soil parameters are sent to a remote terminal for soil data analysis. From the above analysis, since the robot can be remotely controlled to walk on the soil, and the normal stress and shear stress are directly acquired through the sensor without sampling the soil on site, the application range of the soil analysis is improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a flowchart of the present application;

[0034] Figure 2 is a small sinking diagram in an embodiment of the present application;

[0035] Figure 3A large subsidence diagram in the embodiment of the present application;

[0036] Figure 4 A normal stress and shear stress change diagram with subsidence depth in the embodiment of the present application;

[0037] Figure 5 A soil parameter analysis device structure diagram based on foot end stress provided by the present application;

[0038] Figure 6 An internal structure principle block diagram of a terminal device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the present application are described clearly and completely in combination with the embodiments and the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0040] It is found through research that the bearing capacity of soil can be known by analyzing soil parameters. The prior art brings soil back to the laboratory by on-site sampling, which is limited by the number of samples that can be sampled, thereby reducing the application range of soil analysis.

[0041] To solve the above technical problems, the present application provides a soil parameter analysis method, device, equipment and medium based on foot end stress, which solves the problem that the existing soil parameter analysis method has a small application range due to the limitation of sample quantity.

[0042] In embodiment one, the soil parameter analysis method based on foot end stress can be applied to a terminal device, which can be a terminal product with data processing function, such as a computer, etc. In this embodiment, as shown in Figure 1 The soil parameter analysis method based on foot end stress specifically includes the following steps:

[0043] S100, stress data of soil applied to the foot end of a robot is collected by a sensor, the number of stress data is several groups, each group of stress data includes normal stress values and shear stress values corresponding to each subsidence depth, and the shear stress value is the peak shear stress value received by the foot end of the robot;

[0044] S200, linear fitting is performed on each group of normal stress values and shear stress values to obtain a linear equation;

[0045] S300, based on the coefficient of the linear equation, soil parameters are obtained, which are sent to a remote terminal for soil data analysis.

[0046] The soil in the embodiment can be lunar soil or soil on other planets such as the Earth.

[0047] Use to represent the group of stress data, wherein, represents the average normal stress on the foot end when the foot end is sunken to a depth of , and the embodiment takes the average normal stress as the normal stress value in each group of stress data, represents the peak shear stress on the foot end when the foot end is sunken to a depth of .

[0048] ;

[0049] ;

[0050] In the formula, represents the normal stress on the th sampling point on the foot end when the foot end is sunken to a depth of , represents the total number of sampling points, represents the surface area of the foot end sunken into the soil when the foot end is sunken to a depth of , , represents the radius of the foot end, represents the shear stress on the th sampling point on the foot end when the foot end is sunken to a depth of .

[0051] Step S200 linearly fits each group of normal stress values and shear stress values by using the least square method to obtain a linear equation.

[0052] The Mohr-Coulomb criterion in the embodiment is: According to the Mohr-Coulomb criterion, and are in a linear relationship, so the relationship between and can be represented by a linear equation, that is, , wherein represents the dependent variable, corresponds to , represents the independent variable, corresponds to , represents the constant term coefficient, represents the first-order term coefficient, represents the cohesion, represents the internal friction angle.

[0053] By the way of dotting, draw in the coordinate system to get each point, and perform least square fitting on these points to get the value of and the value of . That is, solve the value of by formula (1), and solve the value of by formula (2):

[0054] ; (1)

[0055] ; (2)

[0056] In the formula, the value of and the value of are respectively The value of in the formula (1) and the value of in the formula (2) are substituted into the formula (1) to get the value of, and the value of is substituted into the formula (2) to get the value of.

[0057] Based on the coefficient of the linear equation, the soil parameters are obtained in the step S300, including: taking the value of the constant term coefficient as the cohesion of the soil; taking the arctangent value of the first term coefficient as the internal friction angle of the soil, and taking the cohesion and the internal friction angle as the soil parameters involved in the Mohr-Coulomb criterion.

[0058] Let represent the cohesion, and let represent the internal friction angle, that is, Thus, the value of the cohesion and the value of the internal friction angle are solved. Embodiment Two, based on Embodiment One, the embodiment provides a method for solving the normal stress resultant value and the shear stress resultant value of the soil applied to the foot end of a robot sinking into the soil. The embodiment will solve the normal stress resultant value and the shear stress resultant value of the foot end of the robot for two cases that the part of the foot end of the robot sinking into the soil is less than half of the foot end of the robot and the part of the foot end of the robot sinking into the soil is greater than half of the foot end of the robot.

[0059] That is, the case that the part of the foot end of the robot sinking into the soil (the yellow part in the soil) is less than half of the foot end of the robot, from

[0060] Figure 2 Figure 2 Figure 2 ​​​​​​​​​​​​​​​​​​​It can be seen that the part of the robot foot end sinking into the soil is less than half of the robot foot end, that is, the center O of the foot end is located outside the soil.

[0061] When the part of the robot foot end sinking into the soil is less than half of the robot foot end, solving the normal stress resultant value and the shear stress resultant value includes the following specific steps: obtaining the radius of the robot foot end and the maximum sinking depth corresponding to the foot end bottom; determining the normal stress resultant value and the shear stress resultant value based on the radius, the maximum sinking depth and the soil parameters (the soil parameters include the normal stress resultant value and the shear stress resultant value solved in Embodiment One) and ).

[0062] That is, the normal stress resultant value is solved by formula (3) , and the shear stress resultant value is solved by formula (4) . Similarly, the shear stress resultant value is solved by synthesizing the forces of the shear stresses received by each point on the foot end .

[0063] ; (3)

[0064] ; (4)

[0065] In the formula, represents the maximum sinking depth corresponding to the foot end bottom, represents the sinking depth corresponding to the point on the foot end, since the foot end is spherical, the sinking depths of each point on the sphere are different, represents the soil cohesion modulus, represents the soil friction modulus, represents the sinking index, represents the ground shear displacement, represents the shear deformation modulus, represents the short side length of the pressure plate, that is, the diameter of the cross section formed by the foot end and the soil at the contact point, as shown in Figure 2 , the contact points include A and B, and the cross section is the cross section on the foot end containing A and B and parallel to the horizontal plane on which the soil surface is located.

[0066] The derivation process of formula (3) and formula (4) is as follows:

[0067] Let , represent the angle between the center O of the foot end in Figure 2 and the two contact points A and B; let , representFigure 2 the angle between the contact point A and the foot end center O and the contact point B; let , represent Figure 2 the angle between the contact point B and the foot end center O and the contact point A.

[0068] When the part of the robot foot end sinking into the soil is less than half of the robot foot end, that is , or At this time, the angle expression can be derived from formula (5) and formula (6):

[0069] ; (5)

[0070] ; (6)

[0071] The horizontal direction resultant force represents the driving force provided by the foot end to the robot, and its size affects the movement efficiency of the robot in the soft lunar soil; the vertical direction resultant force represents the support force of the foot end to the robot; to ensure the stability of the robot in the low gravity environment.

[0072] Because the spherical foot end is a curved surface structure, each contact point of the foot end is subjected to the action force composed of two parts of normal stress and shear stress generated by extrusion. Among them, the normal stress is the action force generated by the extrusion between the foot end and the soil, and the action force direction is along the normal direction (the normal direction is parallel to the direction of the line connecting the contact point and the foot end center O), which is irrelevant to the movement direction. On the contrary, the shear stress is the action force generated by the relative movement between the foot end and the soil, and the action force direction is related to the movement direction, which is perpendicular to the normal stress direction and consistent with the movement direction. Because the normal stress and the shear stress act on different positions of the spherical foot end, the directions of the normal stress and the shear stress are different, so it is necessary to decompose the stress.

[0073] When two points on the foot end are symmetrically distributed along the sinking direction, that is, the two points have the same sinking depth or have the same sinking amount, the normal stresses of the two points are the same, so after the normal stresses of the two points are decomposed into horizontal direction and vertical direction, the normal stresses of the two symmetric points in the horizontal direction are mutually offset, and the directions of the normal stresses of the two symmetric points in the vertical direction are the same, so the calculation of the normal stress resultant force value only needs to consider the component force of the normal stress of each point on the foot end in the vertical direction.

[0074] For the shear stresses of the two symmetric points, they are also decomposed into vertical direction and horizontal direction. The component forces of the shear stresses of the two symmetric points in the vertical direction are mutually offset; the component forces of the shear stresses of the two symmetric points in the horizontal direction are the same in direction, so the two component forces are added to obtain the resultant force. Therefore, the shear stress analysis only needs to focus on the component force in the horizontal direction.

[0075] Use to represent normal stress The component in the vertical direction, use to represent shear stress The component in the horizontal direction.

[0076] ; (7)

[0077] ; (8)

[0078] ; (9)

[0079] ; (10)

[0080] In the formula, is the angle between the line connecting the point on the foot end and the foot end center O and the vertical direction, which can be obtained by formula (11) :

[0081] ; (11)

[0082] Normal stress resultant value By accumulating the normal stress components in the vertical direction of each point on the foot end that sinks into the soil (i.e. ), the normal stress resultant value is obtained, that is, based on formula (12) :

[0083] ; (12)

[0084] Wherein, is the circumference length of the part of the foot end that sinks into the soil.

[0085] ; (13)

[0086] Substitute the expression of in formula (13) into formula (12), substitute the expression of in formula (7) into formula (12), and substitute the expression of in formula (11) into formula (12), so formula (12) becomes formula (3).

[0087] Shear stress resultant value By accumulating the shear stress components in the horizontal direction of each point on the foot end that sinks into the soil (i.e. ), the shear stress resultant value is obtained, that is, based on formula (14) :

[0088] ; (14)

[0089] In formula (13) Substituting the expression into formula (14), and using the expression in formula (9) Substituting the expression into formula (14), and changing the expression in formula (11) Substituting the expression into formula (14), formula (14) becomes formula (4).

[0090] The case where the portion of the robot's foot that sinks into the soil is equal to half the size of the robot's foot is also calculated using formula (3). And calculate using formula (4) .

[0091] When the portion of the robot's foot that sinks into the soil is greater than half of the robot's foot, the resultant values ​​of the normal stress and shear stress are calculated, including the following specific steps: obtaining the radius of the robot's foot, the maximum sinking depth corresponding to the bottom of the foot, and the sinking depth of the foot's center from the soil surface; based on the radius, the maximum sinking depth, the sinking depth of the foot's center from the soil surface, and the soil parameters (including those obtained in Example 1)... and The resultant values ​​of the normal stress and the shear stress are determined.

[0092] Figure 3 The image shows a situation where more than half of the robot's foot is sunk into the soil. Figure 3 It can be seen that the part of the robot's foot that sinks into the soil is more than half the length of the robot's foot, meaning that the center O of the foot is located inside the soil.

[0093] If the portion of the robot's foot that sinks into the soil is greater than half of the robot's foot, then the resultant normal stress value can be solved using formula (15). The resultant shear stress value is solved by formula (16). The resultant normal stress is obtained by performing a force composition calculation on the normal stresses at various points on the foot. Similarly, by performing force synthesis calculations on the shear stresses at various points on the foot, the resultant shear stress value can be obtained. .

[0094] (15)

[0095] (16)

[0096] In the formula, Represents the depth of subsidence from the center of the foot to the soil surface, for Figure 3 In other words, That is, the depth of the subsidence at the center of the foot, O, which is the distance between O and the soil surface along the subsidence direction.

[0097] The derivation of formulas (15) and (16) is given below:

[0098] When the part of the robot's foot that sinks into the soil is greater than half of the robot's foot, that is ,or At this point, the angle expression can be derived from formulas (17) and (18):

[0099] (17)

[0100] (18)

[0101] When more than half of the robot's foot is submerged in the soil, and the entire lower half of the foot is in the soil, the contact area of ​​this part remains unchanged. Only the contact area of ​​the upper half changes. As the submersion increases, the angle decreases, and the contact area increases.

[0102] For the normal stress in the upper half of the foot, the horizontal components cancel each other out, while the vertical component points downwards. For the shear stress, the vertical components cancel each other out, while the horizontal component is opposite to the direction of movement. For the normal and shear stresses in the lower half of the foot, the component of the normal stress points upwards, while the component of the shear stress is in the same direction as the direction of movement and opposite to that of the upper half. Therefore, in the calculation process, it is necessary to calculate the upper and lower halves independently to ensure that the directions of the forces are consistent.

[0103] Calculate the normal and shear stresses in the lower half of the foot using... The normal stress in the lower half of the foot is represented by... This represents the shear stress in the lower half of the foot.

[0104] (19)

[0105] (20)

[0106] ;(twenty one)

[0107] ;(twenty two)

[0108] ;(twenty three)

[0109] Calculate the normal stress and shear stress in the upper half of the foot using... The normal stress in the upper half of the foot is represented by... This represents the shear stress in the upper half of the foot.

[0110] ;(twenty four)

[0111] (25)

[0112] (26)

[0113] (27)

[0114] Add the left and right sides of the equations (19) and (24) respectively, and use... represent and The sum of these gives formula (15); by adding the left and right sides of the equations (20) and (25) respectively, we get formula (15); represent and The sum of these gives us formula (16).

[0115] Figure 4 Figure a in the diagram shows the variation of normal stress and shear stress with subsidence depth when the foot radius is 20 mm. Figure 4 Figure b in the diagram shows the variation of normal stress and shear stress with subsidence depth when the foot radius is 30 mm. Figure 4 Figure c in the diagram shows the variation of normal stress and shear stress with subsidence depth when the foot radius is 40 mm. Figure 4 Figure d in the figure shows the variation of normal stress and shear stress with subsidence depth when the foot radius is 50 mm.

[0116] pass Figure 4 It can be seen that when the subsidence is small (meaning the portion of the robot's foot submerged in the soil is less than half its length), the force on the foot increases with the increase of subsidence. This is because the increased contact area between the foot and the soil, as well as the increased normal and shear stresses caused by the increased subsidence, both contribute to the increased force on the foot. When the subsidence reaches the large subsidence stage (meaning the portion of the robot's foot submerged in the soil is greater than half its length), the rate of increase in force on the foot slows down. As the subsidence further increases, the soil above the spherical foot exerts a compressive force on the foot, but because the subsidence is larger at this point, its impact on the force on the foot is greater than the impact on the force above the foot.

[0117] In addition, the change of the foot end size also affects the force on the foot end. With the increase of the foot end size, the normal stress and the shear stress are increased. Through data analysis, it can be concluded that the increase of the foot end size helps to improve the movement ability and movement performance of the quadruped robot. Overall, the force on the foot end is affected by the combination of the subsidence and the foot end size. Smaller foot end size leads to smaller force and is prone to produce larger subsidence.

[0118] The embodiment also provides a soil parameter analysis device based on the force on the foot end, as shown in the figure, the device comprises the following components: Figure 5

[0119] The data acquisition module 01 is used for acquiring stress data of the soil applied to the foot end of the robot through the sensor, the number of the stress data is several groups, each group of the stress data comprises a normal stress value and a shear stress value corresponding to each subsidence depth, and the shear stress value is a peak shear stress value borne by the foot end of the robot;

[0120] The linear fitting module 02 is used for linearly fitting the normal stress value and the shear stress value in each group to obtain a linear equation;

[0121] The data analysis module 03 is used for obtaining soil parameters based on the coefficient of the linear equation, and the soil parameters are used for being sent to a remote terminal to perform soil data analysis.

[0122] Based on the above embodiment, the application further provides a terminal device, and a principle block diagram thereof can be as shown in the figure. Figure 6 The terminal device comprises a processor, a memory, a network interface and a display screen connected through a system bus. The processor of the terminal device is used for providing computing and control capabilities. The memory of the terminal device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium. The network interface of the terminal device is used for communicating with an external terminal through a network connection. The computer program is executed by the processor to implement a soil parameter analysis method based on the force on the foot end. The display screen of the terminal device can be a liquid crystal display screen or an electronic ink display screen.

[0123] Those skilled in the art can understand that, Figure 6 The principle block diagram shown in the figure is only a block diagram of part of the structure related to the application scheme, and does not constitute a limitation on the terminal device to which the application scheme is applied. The specific terminal device can comprise more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0124] ​In one embodiment, a terminal device is provided, the terminal device comprising a memory, a processor, and a foot-end stress-based soil parameter analysis program stored in the memory and executable on the processor, the processor implementing the following operation instructions when executing the foot-end stress-based soil parameter analysis program:

[0125] acquiring stress data of soil applied to a foot end of a robot by a sensor, the stress data being a plurality of groups, each group of the stress data comprising a normal stress value and a shear stress value corresponding to each of the sink depths, the shear stress value being a peak shear stress value applied to the foot end of the robot;

[0126] linearly fitting the normal stress value and the shear stress value of each group to obtain a linear equation;

[0127] obtaining a soil parameter based on a coefficient of the linear equation, the soil parameter being used to send to a remote terminal for soil data analysis.

[0128] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0129] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A soil parameter analysis method based on foot end stress, characterized by, The method comprises the following steps: Collecting stress data of soil applied to a robot foot end by a sensor, the stress data being in a plurality of groups, each group of the stress data comprising normal stress values and shear stress values corresponding to each sinking depth, the shear stress values being peak shear stress values suffered by the robot foot end; Linearly fitting the normal stress values and the shear stress values in each group to obtain a linear equation; Obtaining soil parameters based on coefficients of the linear equation, the soil parameters being used to send to a remote terminal for soil data analysis; Obtaining soil parameters based on the coefficients of the linear equation, comprising: Determining constant term coefficients and linear term coefficients in the coefficients; Taking a value of the constant term coefficients as cohesion of soil; Taking an inverse tangent value of the linear term coefficients as internal friction angle of soil, and taking the cohesion and the internal friction angle as soil parameters involved in a Mohr-Coulomb criterion.

2. The soil parameter analysis method based on foot end stress according to claim 1, wherein, The linear fitting module is configured to linearly fit the normal stress values and the shear stress values in each group to obtain a linear equation, comprising: Linearly fitting the normal stress values and the shear stress values in each group by using a least square method to obtain a linear equation.

3. The soil parameter analysis method based on foot end stress according to any one of claims 1 to 2, characterized by, The method is applied to solving normal stress resultant values and shear stress resultant values of soil applied to a robot foot end sinking in soil.

4. The soil parameter analysis method based on foot end stress according to claim 3, characterized by, The part of the robot foot end sinking in soil is less than half of the robot foot end; solving the normal stress resultant values and the shear stress resultant values of soil applied to the robot foot end sinking in soil, comprising: Obtaining a radius of the robot foot end and a maximum sinking depth corresponding to a bottom of the robot foot end; Based on the radius, the maximum sinking depth and the soil parameters, performing stress analysis on each point on the foot end to determine the normal stress resultant values and the shear stress resultant values.

5. The soil parameter analysis method based on foot end stress according to claim 3, wherein, The part of the robot foot end sinking in soil is greater than half of the robot foot end; solving the normal stress resultant values and the shear stress resultant values of soil applied to the robot foot end sinking in soil, comprising: Obtaining a radius of the robot foot end, a maximum sinking depth corresponding to a bottom of the robot foot end and a sinking depth of a center of the robot foot end from a soil surface; Based on the radius, the maximum sinking depth, the sinking depth of the center of the robot foot end from the soil surface and the soil parameters, performing stress analysis on each point on the foot end to determine the normal stress resultant values and the shear stress resultant values.

6. A soil parameter analysis device based on foot end stress, characterized by, The device comprises the following components: A data collection module configured to collect stress data of soil applied to a robot foot end by a sensor, the stress data being in a plurality of groups, each group of the stress data comprising normal stress values and shear stress values corresponding to each sinking depth, the shear stress values being peak shear stress values suffered by the robot foot end; A linear fitting module configured to linearly fit the normal stress values and the shear stress values in each group to obtain a linear equation; A data analysis module configured to obtain soil parameters based on coefficients of the linear equation, the soil parameters being used to send to a remote terminal for soil data analysis; Obtaining soil parameters based on the coefficients of the linear equation, comprising: Determining constant term coefficients and linear term coefficients in the coefficients; The value of the constant term coefficient is taken as the cohesion of the soil; The inverse tangent value of the linear term coefficient is taken as the internal friction angle of the soil, and the cohesion and the internal friction angle are taken as soil parameters involved in the Mohr-Coulomb criterion.

7. A terminal device, characterized by comprising: The terminal device comprises a memory, a processor, and a foot-end stress-based soil parameter analysis program stored in the memory and executable on the processor, and when the processor executes the foot-end stress-based soil parameter analysis program, the steps of the foot-end stress-based soil parameter analysis method according to any one of claims 1-5 are implemented.

8. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a foot-end stress-based soil parameter analysis program, and when the processor executes the foot-end stress-based soil parameter analysis program, the steps of the foot-end stress-based soil parameter analysis method according to any one of claims 1-5 are implemented.

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