A Design Method for a Vibration-Damping and Protective Sleeve of a Robot Adjusting Flat Top Rod

Abstract

The present invention discloses a design method for a vibration damping and protection sleeve of a robot leveling push rod. First, a three-dimensional model of the vibration damping and protection sleeve is constructed using three-dimensional software; then, parametric modeling of the vibration damping and protection sleeve is carried out using Hypermesh software; then, a collision model of a two-stage energy absorption box is constructed and its reliability is verified; next, an optimization mathematical model is constructed to determine the specific parameters of the inner core of the two-stage energy absorption box; finally, the strength of the vibration damping and protection sleeve is verified. This method achieves the effect of vibration damping and energy absorption by designing a two-stage energy absorption box. The vibration damping and protection sleeve designed by this method has a simple structure, low manufacturing cost, and high practical engineering application value. The dimensional parameters in the vibration damping and protection sleeve are obtained through the optimization model, and the parameter settings in the optimization model can be adjusted according to the actual use situation to obtain matching dimensional parameters. This method has a wide range of applications and a fast optimization convergence speed.

Description

Technical Field

[0001] The present invention relates to a leveling mechanism for a measuring robot, and particularly to a design method for a shock-absorbing and protective sleeve for a leveling jack rod of a measuring robot. Background Art

[0002] The leveling mechanism of a measuring robot mainly relies on the movement of three jack rods for leveling, and the three leveling jack rods are in contact with the leveling reference surface. Under the working conditions of a complex environment, the leveling jack rods often fail due to strong impact vibration. Therefore, it is necessary to design a shock-absorbing and protective sleeve for the leveling jack rods.

[0003] In the design of the shock-absorbing and protective sleeve, a negative Poisson's ratio structure with better shock-absorbing and energy-absorbing performance should generally be selected. When the negative Poisson's ratio multi-cell structure is compressed, the internal structure deforms, the overall structure will shrink, the stiffness becomes larger, and a large amount of energy is converted into the elastic energy and plastic energy of the material. Due to its special mechanical properties, it is widely used in the design of energy-absorbing structures. However, the complex negative Poisson's ratio structure usually needs to be fabricated by 3D printing, but due to the high cost, it seriously hinders the popularization and application of the negative Poisson's ratio multi-cell structure in the actual engineering field. Summary of the Invention

[0004] In view of the problems existing in the design of the shock-absorbing and protective sleeve, the present invention provides a design method for a shock-absorbing and protective sleeve for a leveling jack rod of a measuring robot. This method realizes the effect of shock absorption and energy absorption by designing two-stage energy-absorbing boxes.

[0005] First, use 3D software to construct a 3D model of the shock-absorbing and protective sleeve; then use Hypermesh software to perform parametric modeling on the shock-absorbing and protective sleeve; then construct a collision model of the two-stage energy-absorbing box and verify its reliability; then construct an optimization mathematical model to determine the specific parameters of the inner core of the two-stage energy-absorbing box; finally, verify the strength of the shock-absorbing and protective sleeve.

[0006] The technical solution adopted by the present invention is: a design method for a shock-absorbing and protective sleeve for a leveling jack rod of a measuring robot includes the following steps:

[0007] S1: According to the structural dimensions of the leveling jack rod in the leveling mechanism of the measuring robot, construct a 3D model of the shock-absorbing and protective sleeve.

[0008] S2: Use Hypermesh software to perform parametric simulation modeling on the shock-absorbing and protective sleeve.

[0009] S3: Determine the boundary conditions and load application methods of the shock-absorbing and protective sleeve structure, construct a collision model of the shock-absorbing and protective sleeve, and perform simulation calculations to obtain the simulation collision calculation results.

[0010] S4: Verify the reliability of the shock-absorbing and protective sleeve collision model.

[0011] S5: Allocate the energy absorption indexes of the primary energy absorption box and the secondary energy absorption box of the shock absorption and protection sleeve.

[0012] S6: Construct an optimization mathematical model for the structural optimization of the primary energy absorption box and the secondary energy absorption box. Taking the inner core thickness dimension of the energy absorption box as the design variable, the energy absorption index as the constraint, and the minimum mass as the optimization objective to construct an optimization model. If the optimization mathematical models of the primary energy absorption box and the secondary energy absorption box can both reach the convergent optimal solution, output the inner core thickness dimension of the energy absorption box to obtain the structures of the primary energy absorption box and the secondary energy absorption box; otherwise, it is necessary to modify the optimization parameters until the optimization models of the primary energy absorption box and the secondary energy absorption box can both reach the convergent optimal solution.

[0013] S7: Conduct a static analysis on the primary energy absorption box and the secondary energy absorption box to obtain the stress nephograms of the primary energy absorption box and the secondary energy absorption box.

[0014] S8: According to the maximum stress under the static load shown in the stress nephograms of the primary energy absorption box and the secondary energy absorption box, judge whether the stiffness and strength of the primary energy absorption box and the secondary energy absorption box meet the set thresholds. If their stiffness and strength both meet the set thresholds, output the structural dimensions of the primary energy absorption box and the secondary energy absorption box to complete the structural design of the primary energy absorption box and the secondary energy absorption box; otherwise, return to step S5 to re-allocate the energy absorption indexes of the primary energy absorption box and the secondary energy absorption box.

[0015] S9: Design the structure of the shock absorption and protection sleeve according to the structural dimensions of the primary energy absorption box and the secondary energy absorption box to obtain a shock absorption and protection sleeve that meets the design requirements.

[0016] The shock absorption and energy dissipation of the shock absorption and protection sleeve proposed by the present invention are completed by two - stage energy absorption boxes. When the leveling push rod is subjected to a large impact load, the inner core structure of the primary energy absorption box fails first, and then the inner core structure of the secondary energy absorption box fails, absorbing the energy generated by the impact. This shock absorption and protection sleeve can effectively absorb the impact and vibration loads received during the operation of the measuring robot.

[0017] The beneficial effects produced by the present invention are as follows: The shock absorption and protection sleeve designed by this method has a simple structure, low manufacturing cost, and high practical engineering application value. The dimensional parameters in the shock absorption and protection sleeve are obtained through the optimization model, and the parameter settings in the optimization model can be adjusted according to the actual use situation to obtain matching dimensional parameters. This method has a wide range of applications and a fast optimization convergence speed. Brief Description of the Drawings

[0018] Figure 1 is the schematic diagram of the decomposition of the shock absorption and protection sleeve structure in the embodiment of the present invention;

[0019] Figure 2 is Figure 1 the enlarged top view of the primary energy absorption box in

[0020] Figure 3 is Figure 1 The side view of the enlarged secondary energy absorption box in the present invention;

[0021] Figure 4 is the flowchart of the design method of the embodiment of the present invention;

[0022] Figure 5 is the finite element model of the primary energy absorption box in the embodiment of the present invention;

[0023] Figure 6 is the finite element model of the secondary energy absorption box in the embodiment of the present invention;

[0024] Figure 7 is the schematic diagram of the loading method of the boundary conditions for the static analysis of the primary energy absorption box in the embodiment of the present invention;

[0025] Figure 8 is the schematic diagram of the loading method of the boundary conditions for the static analysis of the secondary energy absorption box in the embodiment of the present invention. Specific embodiments

[0026] The present invention will be further described below in conjunction with the drawings and embodiments:

[0027] As Figure 1 shown, the vibration damping and protection top rod sleeve of the present invention includes a primary energy absorption box 1, a primary energy absorption box cover 2, a secondary energy absorption box 3 and a sleeve 4; the primary energy absorption box 1 is fixed on the top of the secondary energy absorption box 3 by screws, the primary energy absorption box cover 2 is fixed on the primary energy absorption box 1 by screws, the side of the secondary energy absorption box 3 is fixed to the sleeve 4 by four screws, and the side of the bottom end of the sleeve 4 is fixed to the leveling top rod 5 by screws.

[0028] The connection of the components inside the vibration damping and protection sleeve is all rigidly connected by M6 screws.

[0029] As Figure 2 shown, the inner core of the primary energy absorption box 1 of the vibration damping and protection sleeve is set as a regularly distributed concave hexagon. As Figure 3 shown, the inner core of the secondary energy absorption box 3 is set as a regular hexagon. The primary energy absorption box cover 2 at the top of the primary energy absorption box 1 is in contact with the leveling reference surface of the leveling mechanism of the measuring robot, and the worm and gear drive the leveling top rod 5 to move telescopically to achieve leveling.

[0030] As Figure 4 shown, a design method for the vibration damping and protection sleeve for the leveling top rod of a measuring robot includes the following steps:

[0031] S1: According to the structural dimensions of the leveling top rod in the leveling mechanism of the measuring robot, construct a three-dimensional model of the vibration damping and protection sleeve. The modeling process of the vibration damping and protection sleeve is completed on the UG platform.

[0032] S2: Use Hypermesh software to perform parametric simulation modeling on the vibration damping and protection sleeve. During the parametric simulation modeling of the vibration damping and protection sleeve, the PSHELL element in Hypermesh software is used for modeling, and the inner core thickness dimensions of the primary energy absorption box and the secondary energy absorption box of the vibration damping and protection sleeve are parameterized.

[0033] S3: Determine the boundary conditions and load application methods of the vibration damping and protection sleeve structure, construct a collision model of the vibration damping and protection sleeve, and perform simulation calculations to obtain the simulation collision calculation results. The boundary conditions of the vibration damping and protection sleeve structure are: fix the six degrees of freedom of the bottom surfaces of the primary energy absorption box and the secondary energy absorption box; the load application method is: the rigid wall moves towards the energy absorption box at a speed of 4160 m / s.

[0034] S4: Verify the reliability of the vibration damping and protection sleeve collision model. The reliability criterion for verifying the vibration damping and protection sleeve collision model is: if the ratio of the hourglass energy parameter in the simulation collision calculation results of the vibration damping and protection sleeve to the total energy generated by the collision is less than 5%, it indicates that the constructed vibration damping and protection sleeve collision model is reliable; if the ratio of the hourglass energy parameter in the simulation collision calculation results of the vibration damping and protection sleeve to the total energy generated by the collision is greater than or equal to 5%, it indicates that the collision simulation calculation results are incorrect, and the vibration damping and protection sleeve collision model needs to be modified.

[0035] S5: Allocate the energy absorption indicators of the primary energy absorption box and the secondary energy absorption box of the vibration damping and protection sleeve. The energy absorption indicator allocation principle for the primary energy absorption box and the secondary energy absorption box of the vibration damping and protection sleeve is: the total energy absorption of the primary energy absorption box is 1 / 2 times that of the secondary energy absorption box; the numerical value of the total energy absorption of the primary energy absorption box and the secondary energy absorption box is expressed as the integral of the impact force and the deformation amount of the energy absorption block during the collision, and the expression is as follows:

[0036]

[0037] In the formula, E TOTAL is the total energy absorption of the primary energy absorption box and the secondary energy absorption box, unit: KJ; F(S) is the function of the impact force and the deformation amount of the energy absorption block; T is the duration of the collision process, unit: s.

[0038] S6: Construct an optimization mathematical model for the structures of the primary energy absorption box and the secondary energy absorption box. Taking the inner core thickness dimensions of the energy absorption box as the design variables, the energy absorption indicators as the constraints, and the minimum mass as the optimization objective to construct the optimization model. If the optimization mathematical models for the structures of the primary energy absorption box and the secondary energy absorption box can both obtain convergent optimal solutions, then output the inner core thickness dimensions of the energy absorption box to obtain the structures of the primary energy absorption box and the secondary energy absorption box; otherwise, the optimization parameters need to be modified until the optimization models for the primary energy absorption box and the secondary energy absorption box can both obtain convergent optimal solutions.

[0039] The structural optimization mathematical model of the primary energy absorption box is as follows:

[0040]

[0041] In the formula, E TOTAL1 is the total energy absorption of the primary energy absorption box, unit: KJ; E obj1 is the target energy absorption value of the primary energy absorption box, unit: KJ; t 1 is the thickness dimension of the inner core of the primary energy absorption box, unit: mm; { t 10 , t 11 , t 12 , t 13 , t 14 , t 15 , …… t 1n} is the value range of the thickness dimension of the inner core of the primary energy absorption box, unit: mm; M 1 is the mass of the primary energy absorption box, unit: kg; M 1 D is the lower limit of the mass of the primary energy absorption box, unit: kg; M 1 U is the upper limit of the mass of the primary energy absorption box, unit: kg; ρ is the material density, unit: kg / m 3 .

[0042] During the optimization process, the total energy absorption of the primary energy absorption box at each iteration step E TOTAL1 is calculated in Lsdyna; the mass of the primary energy absorption box at each iteration step M 1 is calculated in the Optistruct solver.

[0043] The structural optimization mathematical model of the secondary energy absorption box is as follows:

[0044]

[0045] In the formula, E TOTAL2 is the total energy absorption of the secondary energy absorption box, unit: KJ; E obj2 is the target energy absorption value of the secondary energy absorption box, unit: KJ; t 2is the thickness dimension of the inner core of the secondary energy absorption box, unit: mm; { t 20 , t 21 , t 22 , t 23 , t 24 , t 25 , …… t 2n} is the value range of the thickness dimension of the inner core of the secondary energy absorption box, unit: mm; M 2 is the mass of the secondary energy absorption box, unit: kg; M 2 D is the lower limit of the mass of the secondary energy absorption box, unit: kg; M 2 U is the upper limit of the mass of the secondary energy absorption box, unit: kg; ρ is the material density, unit: kg / m 3 .

[0046] During the optimization process, the total energy absorption of the secondary energy absorption box at each iteration step E TOTAL2 is calculated in Lsdyna; the mass of the secondary energy absorption box at each iteration step M 2 is calculated in the Optistruct solver.

[0047] If the structural optimization mathematical model of the primary energy absorption box and the secondary energy absorption box does not converge, it is necessary to relax the relative convergence condition and increase the tolerance of the relative change of the objective function between two adjacent iteration steps.

[0048] S7: Perform a static analysis on the primary energy absorption box and the secondary energy absorption box to obtain the stress nephograms of the primary energy absorption box and the secondary energy absorption box.

[0049] The boundary conditions for the static analysis of the primary energy absorption box and the secondary energy absorption box are: fix the six degrees of freedom of the bottom surface of the primary energy absorption box and the secondary energy absorption box; the load magnitude on the top surface of the primary energy absorption box and the secondary energy absorption box is obtained through the following calculation formula:

[0050]

[0051] In the formula, M is the total weight of the leveling mechanism of the measuring robot, unit: kg; g is the acceleration due to gravity, with a value of 9.8 m / s 2 ; S is the top surface area of the primary energy absorption box and the secondary energy absorption box, unit: m2 ; N For measuring the number of leveling top rods of the leveling mechanism of the measuring robot P is the pressure to be applied to the top surfaces of the primary energy absorption box and the secondary energy absorption box, unit: MPa.

[0052] S8: According to the maximum stress under static load shown by the primary energy absorption box and the secondary energy absorption box in the stress contour map, judge whether the stiffness and strength of the primary energy absorption box and the secondary energy absorption box meet the set thresholds. If both the stiffness and strength are less than or equal to the set thresholds, output the structural dimensions of the primary energy absorption box and the secondary energy absorption box to complete the structural design of the primary energy absorption box and the secondary energy absorption box; otherwise, return to step S5 to re-allocate the energy absorption indexes of the primary energy absorption box and the secondary energy absorption box.

[0053] The judgment rules for the strength of the primary energy absorption box and the secondary energy absorption box are as follows:

[0054]

[0055] In the formula, σ max is the maximum stress of the primary energy absorption box and the secondary energy absorption box under static load, unit: MPa; [σ] / n is the set threshold, unit: MPa; [σ] is the yield limit of the materials of the primary energy absorption box and the secondary energy absorption box, unit: MPa; n is the safety factor.

[0056] If the maximum stress of the primary energy absorption box and the secondary energy absorption box under static load meets the judgment rules, it indicates that the structural strength of the primary energy absorption box and the secondary energy absorption box meets the usage requirements; otherwise, it indicates that the structural strength of the primary energy absorption box and the secondary energy absorption box does not meet the usage requirements.

[0057] S9: According to the structural dimensions of the primary energy absorption box and the secondary energy absorption box, design the structure of the shock-absorbing and protective sleeve to obtain a shock-absorbing and protective sleeve that meets the design requirements. The structural design of the shock-absorbing and protective sleeve should fully consider the dimensions of the leveling top rod. Determine the length and inner diameter of the shock-absorbing and protective sleeve according to the length and diameter of the leveling top rod.

[0058] Example: In this example, it is listed that the leveling mechanism of the mine measuring robot is leveled by three leveling top rods. The diameter of the leveling top rod is 30 mm, the length is 40 mm, and the material of the leveling top rod is high-strength steel. The total weight of the measuring robot is 180 kg. The material of the primary energy absorption box is aluminum alloy, and the dimensions of length, width and height are 32 mm × 32 mm × 32 mm; the material of the secondary energy absorption box is aluminum alloy, the diameter is 45 mm, and the thickness is 20 mm. The density of the aluminum alloy material is 2.7×10 3 kg / m 3 , and the yield limit is 55.2 MPa.

[0059] The finite element model of the first - stage energy - absorbing box is as shown in Figure 5 Figure. The finite element model of the first - stage energy - absorbing box is modeled using PSHELL elements. The element type is quadrilateral elements, and the total number of elements is 1960.

[0060] The finite element model of the second - stage energy - absorbing box is as shown in Figure 6 Figure. The finite element model of the second - stage energy - absorbing box is modeled using PSHELL elements. The element type is quadrilateral elements, and the total number of elements is 956.

[0061] The boundary conditions of the vibration - damping and protection sleeve collision model are: fixing the 6 degrees of freedom of the bottom surface of the energy - absorbing box. The load - loading condition is: the rigid wall moves towards the direction close to the energy - absorbing box at a speed of 4160 m / s.

[0062] According to the actual use environment of the measuring robot, the energy - absorption index distribution of the two - stage energy - absorbing box is: the total energy absorbed by the first - stage energy - absorbing box is 400 KJ, and the total energy absorbed by the second - stage energy - absorbing box is 800 KJ. The parameter values in the structural optimization mathematical model of the first - stage energy - absorbing box are: { t 10 , t 11 , t 12 , t 13 , t 14 , t 15 , …… t 1n} = {0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2}; M 1 D = 50 g; M 1 U = 200 g; E obj1 = 400 KJ.

[0063] The parameter values in the structural optimization mathematical model of the second - stage energy - absorbing box are: { t 20 , t 21 , t 22 , t 23 , t 24 , t 25 , …… t 2n} = {0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2}; M 2 D = 50 g; M 2 U = 200 g; E obj2 = 800 KJ.

[0064] After the two - stage energy - absorbing box is optimized, the inner core thickness dimension of the first - stage energy - absorbing box is 0.8 mm; the inner core thickness dimension of the second - stage energy - absorbing box is 1.2 mm.

[0065] The load magnitude applied to the top surface of the first - stage energy - absorbing box is:

[0066]

[0067] The strength check boundary condition of the first - stage energy - absorbing box is: fix 6 degrees of freedom of the bottom surface of the first - stage energy - absorbing box, and apply a pressure of 0.57 MPa on the top surface (as Figure 7 shown).

[0068] The load magnitude applied to the top surface of the second - stage energy - absorbing box is:

[0069]

[0070] The strength boundary condition of the second - stage energy - absorbing box is: fix 6 degrees of freedom of the bottom surface of the second - stage energy - absorbing box, and apply a pressure of 0.1 MPa on the top surface (as Figure 8 shown).

[0071] After determining the load applied to the top surfaces and the boundary conditions of the first - stage and second - stage energy - absorbing boxes, perform simulation calculations on the first - stage and second - stage energy - absorbing boxes to obtain the stress nephogram, and obtain the maximum stress values of the first - stage and second - stage energy - absorbing boxes under static load from the stress nephogram for strength judgment.

[0072] Static analysis result of the first - stage energy - absorbing box: The maximum stress of the first - stage energy - absorbing box under static load is 7.607 MPa, that is, σ max = 7.607 MPa. According to the strength judgment rule of the energy - absorbing box, the yield limit [σ] of the material in this embodiment takes a value of 55.2 MPa, and the safety factor n takes 2, and the judgment threshold can be obtained as [σ] / n = 55.2 / 2 = 27.6 MPa. Substituting into the strength judgment rule, we can get

[0073]

[0074] Through calculation, it can be obtained that the maximum stress of the primary energy absorption box under static load meets the strength requirements.

[0075] Static analysis results of the secondary energy absorption box: The maximum stress of the secondary energy absorption box under static load is 4.44 MPa, that is, σ max = 4.44 MPa. According to the strength judgment rule of the energy absorption box, the yield limit [σ] of the material in this embodiment is 55.2 MPa, and the safety factor n is taken as 2. The judgment threshold can be obtained as [σ] / n = 55.2 / 2 = 27.6 MPa. Substituting it into the strength judgment rule, we can get

[0076]

[0077] Through calculation, it can be obtained that the maximum stress of the secondary energy absorption box under static load meets the strength requirements.

[0078] According to the dimensions of the adjusting flat rod, the inner diameter of the shock-absorbing and protective sleeve can be obtained as 30 mm, and the internal depth is 40 mm.

Claims

1. A design method for a shock-absorbing and protective sleeve for a leveling top rod of a measuring robot, characterized in that, the design method comprises the following steps: S1: Construct a three-dimensional model of the shock-absorbing and protective sleeve according to the structural dimensions of the leveling top rod in the leveling mechanism of the measuring robot; S2: Perform parametric simulation modeling on the shock-absorbing and protective sleeve using Hypermesh software; S3: Determine the boundary conditions and load application methods of the shock-absorbing and protective sleeve structure, construct a collision model of the shock-absorbing and protective sleeve, and perform simulation calculations to obtain simulation collision calculation results; S4: Verify the reliability of the shock-absorbing and protective sleeve collision model; S5: Allocate the energy absorption indexes of the primary energy absorption box and the secondary energy absorption box of the shock-absorbing and protective sleeve; S6: Construct an optimization mathematical model for the structural optimization of the primary energy absorption box and the secondary energy absorption box. Taking the inner core thickness dimension of the energy absorption box as the design variable, the energy absorption index as the constraint, and the minimum mass as the optimization goal to construct an optimization model. If the optimization mathematical models of the primary energy absorption box and the secondary energy absorption box can both reach the convergent optimal solution, then output the inner core thickness dimension of the energy absorption box to obtain the structures of the primary energy absorption box and the secondary energy absorption box; otherwise, it is necessary to modify the optimization parameters until the optimization models of the primary energy absorption box and the secondary energy absorption box can both reach the convergent optimal solution; S7: Perform a static analysis on the primary energy absorption box and the secondary energy absorption box to obtain the stress nephograms of the primary energy absorption box and the secondary energy absorption box; S8: According to the maximum stress under the static load shown in the stress nephograms of the primary energy absorption box and the secondary energy absorption box, judge whether the stiffness and strength of the primary energy absorption box and the secondary energy absorption box meet the set thresholds. If their stiffness and strength both meet the set thresholds, then output the structural dimensions of the primary energy absorption box and the secondary energy absorption box to complete the structural design of the primary energy absorption box and the secondary energy absorption box; otherwise, return to step S5 to re-allocate the energy absorption indexes of the primary energy absorption box and the secondary energy absorption box; S9: Design the structure of the shock-absorbing and protective sleeve according to the structural dimensions of the primary energy absorption box and the secondary energy absorption box to obtain a shock-absorbing and protective sleeve that meets the design requirements.

2. The design method for a shock-absorbing and protective sleeve for a leveling top rod of a measuring robot according to claim 1, characterized in that, the shock-absorbing and protective sleeve comprises a primary energy absorption box, a primary energy absorption box cover, a secondary energy absorption box and a sleeve; the primary energy absorption box is fixed on the top of the secondary energy absorption box, the primary energy absorption box cover is fixed on the primary energy absorption box, the side of the secondary energy absorption box is fixed to the sleeve, and the side of the bottom end of the sleeve is fixed to the leveling top rod.

3. The design method for a shock-absorbing and protective sleeve for a leveling top rod of a measuring robot according to claim 2, characterized in that, the inner core of the primary energy absorption box of the shock-absorbing and protective sleeve is set as regularly distributed concave hexagons, and the inner core of the secondary energy absorption box is set as regular hexagons.

4. The design method for a shock-absorbing and protective sleeve for a leveling top rod of a measuring robot according to claim 1, characterized in that, In step S2, during the parametric simulation modeling of the shock-absorbing and protective sleeve, the PSHELL element in Hypermesh software is used for modeling, and the inner core thickness dimensions of the primary energy-absorbing box and the secondary energy-absorbing box of the shock-absorbing and protective sleeve are parameterized.

5. A design method for a shock-absorbing and protective sleeve for a measuring robot leveling rod according to claim 1, wherein, In step S3, the boundary conditions of the shock-absorbing and protective sleeve structure are: fixing the six degrees of freedom of the bottom surfaces of the primary energy-absorbing box and the secondary energy-absorbing box; the load loading method is: a rigid wall moves towards the direction close to the energy-absorbing box at a speed of 4160 m / s.

6. A design method for a shock-absorbing and protective sleeve for a measuring robot leveling rod according to claim 1, wherein, In step S4, the reliability criterion for verifying the collision model of the shock-absorbing and protective sleeve is: if the ratio of the hourglass energy parameter in the simulation collision calculation result of the shock-absorbing and protective sleeve to the total energy generated by the collision is less than 5%, it indicates that the constructed collision model of the shock-absorbing and protective sleeve is reliable; if the ratio of the hourglass energy parameter in the simulation collision calculation result of the shock-absorbing and protective sleeve to the total energy generated by the collision is greater than or equal to 5%, it indicates that the collision simulation calculation result is incorrect, and the collision model of the shock-absorbing and protective sleeve needs to be modified.

7. A design method for a shock-absorbing and protective sleeve for a measuring robot leveling rod according to claim 1, wherein, In step S5, the energy-absorbing index distribution principle of the primary energy-absorbing box and the secondary energy-absorbing box of the shock-absorbing and protective sleeve is: the total energy absorbed by the primary energy-absorbing box is 1 / 2 times that of the secondary energy-absorbing box; the numerical value of the total energy absorbed by the primary energy-absorbing box and the secondary energy-absorbing box is expressed as the integral of the impact force and the deformation amount of the energy-absorbing block during the collision, and the expression is as follows: ； In the formula, E TOTAL is the total energy absorption of the primary energy absorption box and the secondary energy absorption box, unit: KJ; F(S) is a function of the impact force and the deformation of the energy absorption block; T is the duration of the collision process, unit: s.

8. A design method for a shock-absorbing and protective sleeve for a measuring robot leveling rod according to claim 1, wherein, In step S6, the structural optimization mathematical model of the primary energy-absorbing box is: ； Wherein, E TOTAL1 is the total energy absorption of the first-level energy absorption box, unit: KJ; E obj1 is the target energy absorption value of the first-level energy absorption box, unit: KJ; t 1 is the thickness dimension of the inner core of the first-level energy absorption box, unit: mm; { t 10 , t 11 , t 12 , t 13 , t 14 , t 15 , …… t 1n} is the value range of the inner core thickness dimension of the first-level energy absorption box, unit: mm; M 1 is the mass of the first-level energy absorption box, unit: kg; M 1 D is the lower limit of the mass of the first-level energy-absorbing box, unit: kg; M 1 U is the upper limit of the mass of the first-level energy-absorbing box, unit: kg; ρ is the material density, unit: kg / m 3 ; Lsdyna and Optistruct are both solvers; The structural optimization mathematical model of the secondary energy-absorbing box is: ； Wherein, E TOTAL2 is the total energy absorption of the secondary energy absorption box, unit: KJ; E obj2 is the target energy absorption value of the secondary energy absorption box, unit: KJ; t 2 is the thickness dimension of the inner core of the secondary energy absorption box, unit: mm; { t 20 , t 21 , t 22 , t 23 , t 24 , t 25 , …… t 2n} is the value range of the thickness dimension of the inner core of the secondary energy absorption box, unit: mm; M 2 is the mass of the secondary energy absorption box, unit: kg; M 2 D is the lower limit of the mass of the secondary energy absorption box, unit: kg; M 2 U is the upper limit of the mass of the secondary energy absorption box, unit: kg; ρ is the material density, unit: kg / m 3 ; Lsdyna and Optistruct are both solvers; If the structural optimization mathematical models of the primary energy-absorbing box and the secondary energy-absorbing box do not converge, it is necessary to relax the relative convergence condition and increase the tolerance of the relative change amount of the objective function between adjacent two iterative steps.

9. A design method for a shock-absorbing and protective sleeve for a measuring robot leveling rod according to claim 1, wherein, In step S7, the boundary conditions for the static analysis of the primary energy-absorbing box and the secondary energy-absorbing box are: fixing the six degrees of freedom of the bottom surfaces of the primary energy-absorbing box and the secondary energy-absorbing box; the load magnitudes on the top surfaces of the primary energy-absorbing box and the secondary energy-absorbing box are obtained through the following calculation formula: ； In the formula, M is the total weight of the leveling mechanism of the measuring robot, unit: kg; g is the acceleration due to gravity, with a value of 9.8 m / s 2 ; S is the top surface area of the first - stage energy - absorbing box and the second - stage energy - absorbing box, unit: m 2 ; N is the number of leveling rods of the leveling mechanism of the measuring robot; P is the pressure to be applied to the top surfaces of the first - stage energy - absorbing box and the second - stage energy - absorbing box, unit: MPa.

10. A design method for a shock-absorbing and protective sleeve for a measuring robot leveling rod according to claim 1, wherein, In step S8, the determination rules for the strength of the primary energy-absorbing box and the secondary energy-absorbing box are as follows: ； Where, σ max is the maximum stress of the first-stage energy absorber and the second-stage energy absorber under static load, unit: MPa; [σ] / n is the set threshold value, unit: MPa; [σ] is the yield limit of the materials of the first-stage energy absorber and the second-stage energy absorber, unit: MPa; n is the safety factor; If the maximum stresses of the primary energy-absorbing box and the secondary energy-absorbing box under static load meet the said judgment rule, it indicates that the structural strength of the primary energy-absorbing box and the secondary energy-absorbing box meets the usage requirements; otherwise, it indicates that the structural strength of the primary energy-absorbing box and the secondary energy-absorbing box does not meet the usage requirements.

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