Crawler track single body structure imitating goat hoof tip

Abstract

A goat hoof tip imitating caterpillar band single body structure comprises a caterpillar band single body base body, a linear grouser and bionic unit structures, the bionic unit structures are obtained by stretching bionic hoof tips in a curve mode and then arranging the bionic hoof tips in a permutation and combination mode, and the bionic unit structures are arranged on the linear grouser. Wherein the bionic hoof tip unit structure is obtained by longitudinally stretching a bionic prototype right front hoof inner side hoof tip after a structure curve is extracted, and the bionic prototype right front hoof inner side hoof tip is obtained by combining the motion gait under the optimal attachment coefficient of goat hoof palm structure characteristics and motion characteristic analysis under multiple gradients. And determining the characteristic part with the most obvious effect under the maximum vertical counter force and vertical impulse. The soil cutting surface structure changes the soil cutting surface structure of a traditional single crawler belt, the soil disturbance area is increased, the adhesion performance of the single crawler belt is enhanced, the passing performance of an agricultural crawler vehicle is improved, and discrete element simulation and soil bin verification tests show that the adhesion performance of the bionic structure of the single crawler belt is obviously improved compared with that of a linear grouser structure.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering bionics, and in particular relates to a crawler monomer structure imitating goat hoof tips. Background Art

[0002] At present, with the comprehensive development of agricultural intelligence, the mechanization level of farming, planting and harvesting in various regions of my country has been significantly improved. However, the hilly and mountainous areas have complex terrain, poor field roads, and many plots of land, scattered distribution, difficult mechanized farming, and low efficiency, resulting in a low level of agricultural mechanization. Therefore, optimizing the design of the key components of efficient agricultural machinery in hilly and mountainous areas and accelerating the filling of the shortcomings of agricultural mechanization in hilly and mountainous areas are still important contents of the current development of agricultural machinery.

[0003] The engine power of agricultural tracked vehicles in hilly and mountainous areas is relatively large, and its dynamic performance meets the traction requirements, but the track adhesion performance is weak, and it is easy to slip during driving, climbing, crossing obstacles, and crossing ditches. The track unit is a key component that touches the soil, and its structural parameters affect the vehicle's adhesion and passing ability. Through the study of the track unit adhesion model, the interaction between the track unit's cutting surface and the soil is the key influencing factor when the track unit shears the soil. At present, the research on the adhesion performance of tracked vehicles mainly focuses on the influence of factors such as track force, grouser structure, and grouser height on the adhesion performance of tracked vehicles. There are few studies involving adjusting the interaction between the grouser cutting surface and the soil based on factors such as track pattern and arrangement to improve adhesion performance. Summary of the invention

[0004] In order to overcome the above shortcomings, the present invention discloses a track monomer structure imitating the hoof tip of a goat, which improves the adhesion performance of the track monomer by adjusting the interaction between the track cutting surface and the soil, and improves the passing performance of agricultural track vehicles in hilly and mountainous areas. In order to achieve the above purpose, the technical solution adopted by the present invention is: A single body structure of a track imitating a goat hoof tip comprises a single body matrix, a straight-line spur and a bionic unit structure, wherein the bionic unit structure is obtained by stretching a bionic hoof tip curve and arranging it in an arrangement and combination manner, and the bionic unit structure is arranged on the straight-line spur, wherein the bionic unit structure is placed according to the movement characteristics of the goat hoof.

[0005] Further optimization, the bionic hoof tip curve is based on the kinematic analysis conclusion of the functional parts of the goat hoof. By combining the comparison of vertical reaction force and vertical impulse under multiple slopes and the comparison of adhesion coefficient under multiple slopes, the action parts are determined to be the inner hoof tip of the right front hoof and the inner hoof tip of the left hind hoof, and the bionic hoof tip curve is extracted. The bionic curve satisfies the equation: y=-3.918x 2 +3.902x+0.01873 Among them, 0≤x≤1mm.

[0006] A design method for a crawler monomer structure imitating a goat hoof tip specifically comprises the following steps: S1, through the comparison of vertical ground reaction force and vertical impulse under multiple slopes and adhesion under multiple slopes Coefficient comparison analysis determines the bionic prototype; S2, segmenting the hoof tip target area and extracting the external contour of the hoof tip; S3, converting the extracted hoof tip curve contour point data into coordinate information, and performing polynomial fitting to obtain the bionic curve, using this as the theoretical equation for the design of the bionic unit structure, designing the bionic unit structure, and the bionic curve satisfies the equation: y=-3.918x 2 +3.902x+0.01873; S4, measure the opening angle of sheep hoof flap; S5, arranging the shoe surface pattern according to steps S3 and S4, and designing a bionic hoof tip structure with a hoof petal opening angle on this basis; S6. According to the functional simulation method, the bionic hoof tip structure is arranged on the straight spur as required, thereby forming a bionic unit structure.

[0007] Further optimization, the bionic prototype in step S1 is the inner hoof tip of the right front hoof at a slope of 10°.

[0008] Further optimization, the specific method of step S2 is: image segmentation is achieved by marking target points, the hoof tip target area is extracted, and contour data is obtained by graying, binarization, and edge detection.

[0009] Further optimization, the specific method of step S4 is: analyzing the dynamic video of the hoof opening angle of goats at a slope of 10°, extracting the frame image when the right front hoof and the left hind hoof are diagonally supported, and using an angle measurement tool to obtain that the hoof opening angle of the goat is 40°.

[0010] The beneficial effects of the present invention are: The present invention takes the hoof of a goat as a bionic prototype, extracts the inner hoof tip structure of the right front hoof of the goat according to the movement characteristics of the goat under multiple slopes and the dynamic characteristics of the hoof pressure, and uses this as the bionic unit structure to explore its arrangement and combination methods. Based on functional simulation, a bionic hoof tip track monomer structure with a hoof petal opening angle is designed to optimize the adhesion performance of the track monomer, thereby improving the passing performance of agricultural tracked vehicles. This has important theoretical significance and engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the vertical reaction force diagram of the characteristic functional parts of the goat's hoof under a slope of 10°; Figure 2This is the peak change diagram of vertical reaction force of the characteristic functional parts of goat hoof under different slopes; Figure 3 This is the vertical impulse diagram of the characteristic functional parts of the hoof of goats under a slope of 10°; Figure 4 The vertical impulse changes of the characteristic functional parts of goat hoof under different slopes; Figure 5 This is the angle diagram of the right front hoof flap opening; Figure 6 This is a schematic diagram of Labelme operation; Figure 7 Flow chart for hoof tip contour extraction operation; Figure 8 Extraction diagram of hoof tip contour curve; Fig. 9 This is the structural diagram of the bionic hoof tip unit; Fig.10 It is a single structure of bionic track Fig.11 It is a bionic track monomer structure X; Fig.12 The force variation curves of the simulated bionic track monomer structure and the straight track spur structure are shown. DETAILED DESCRIPTION

[0012] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is described in detail below in conjunction with specific embodiments. The following embodiments are implemented based on the technical solutions of the present invention, and detailed implementation methods and specific operating procedures are given. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the following embodiments.

[0013] According to the comparative analysis of vertical ground reaction force and vertical impulse under multiple slopes, it is found that the accumulation effect of vertical ground reaction force is most significant on the right front hoof during goat climbing, and the main bearing part of the vertical ground reaction force of the right front hoof is transferred from the outer hoof tip to the inner hoof tip; according to the comparative analysis of adhesion coefficient under multiple slopes, it is determined that the adhesion coefficient is the largest when the right front hoof and the left rear hoof are in a diagonal two-phase support state under a slope of 10°. It can be seen from Tables 1 and 2 that at this time, the inner hoof tip of the right front hoof and the inner hoof tip of the left rear hoof play a decisive role. Therefore, the inner hoof tip of the right front hoof under a slope of 10° is selected as the bionic prototype.

[0014] Table 1 Comparison of peak changes in vertical ground reaction forces at characteristic functional parts of goat hooves at different slopes Table 2 Comparison of vertical impulse changes in characteristic functional parts of goat hooves at different slopes The dynamic video of the hoof opening angle of goats on a 10° slope was analyzed, and the frame images of the right front hoof and the left hind hoof when they were diagonally supported were extracted using Python software. The OpenCV angle measurement tool was used to obtain that the hoof opening angle of the goat was 40°.

[0015] The deep learning tool Labelme is used to annotate target points for image segmentation. The Labelme operation interface is as follows: Figure 6 As shown in the figure, the target area of ​​the hoof tip is extracted, and the contour data is obtained through grayscale, binarization, and edge detection. The operation results are shown in Figure 7 shown.

[0016] The extracted hoof tip curve contour point data was converted into coordinate information, and polynomial fitting was performed using the Curve Fitting Toolbox in Matlab. The fitting results are shown in Table 3.

[0017] Table 3 Polynomial fitting results of hoof tip curve Analysis of Table 3 shows that as the number of independent variables increases, the error sum of squares (SSE) decreases and the coefficient of determination (R 2 ) increases, the root mean square error (RMSE) decreases, and when the number of independent variables n is 2 or 3, the modified coefficient of determination (Adj-R 2 ) are the same, SSE, R 2 , RMSE are basically the same. Considering that the second-order curve is easier to realize than the third-order curve in the actual processing of the track pattern, when n=2 is selected, the curve equation of the inner side of the right front hoof is obtained, as shown in the formula: y=-3.918x 2 +3.902x+0.01873,0≤x≤1mm.

[0018] The curve equation of the inner hoof tip of the right front hoof was imported into SolidWorks 2022 software to draw the hoof tip curve, and the bionic unit structure was formed after longitudinal stretching, as shown in the figure. Figure 8 shown.

[0019] In order to explore the influence of row spacing, arrangement mode and bionic unit thickness on track adhesion performance, an orthogonal test method was used to set up a three-factor three-level orthogonal test to determine the optimal arrangement and combination of bionic unit structures. The factor level table is shown in Table 4.

[0020] Table 4 Orthogonal test factor level table The orthogonal test group numbers are shown in Table 5. According to the requirements in the table, the bionic crawler single - body structure is designed respectively. Since the principle of the hoof sole grasping soil during the goat's walking is the same as that of the stud cutting soil, according to the functional simulation method, the bionic units are arranged on the straight - type studs as required. Considering the size of the crawler vehicle used for actual engineering drawing and soil trough test verification, the parameters of the crawler single - body structure are designed as: length×width×height = 100mm×100mm×20mm. Among them, the height includes the stud height of 12mm and the height of the crawler single - body matrix of 8mm.

[0021] Table 5 Orthogonal test group numbers After scaling the bionic unit as a whole by 3 times, it is arranged on the stud cutting surface. The bionic crawler single - body structure is as Fig.10 shown.

[0022] The discrete element software EDEM is used to construct a crawler - soil simulation system for numerical simulation analysis of the bionic crawler single - body structure, study the influence of different pattern arrangement combinations on the adhesion performance of the crawler single - body, and then verify the rationality and superiority of the bionic crawler pattern design.

[0023] Set the reference coordinate system according to the goat's walking direction and the layout direction of the bionic unit structure and import the crawler single - body model. During the EDEM simulation analysis, adjust the position of the crawler single - body model so that it stays 28mm above the soil particle bed, and at the same time ensure that the distance from the four sides to the edge of the soil bed is greater than 200mm to prevent boundary effects.

[0024] According to the range and variance analysis of the three - factor and three - level orthogonal test in Tables 6, 7, and 8, it is determined that the column spacing is 4mm, arranged in two rows, and the thickness of the bionic unit is 3mm as the optimal arrangement combination method. Design the bionic crawler single - body structure X, as Fig.11 shown. Import this structure into the EDEM software to simulate and analyze the maximum value of the soil horizontal force, that is, the adhesion value. The boundary parameters and simulation steps in the simulation environment are the same as above.

[0025] Table 6 Orthogonal test table Table 7 Range analysis results Table 8 Range analysis results Note: "p≤0.01" indicates that this factor is very significant (**); "0.01 < p≤0.05" indicates that this factor is significant (*); "p > 0.05" indicates that this factor is not significant.

[0026] The nine bionic track monomer structures in Table 5 are represented by I-IX respectively, and the bionic track structure designed with the optimal arrangement and combination of bionic unit structures is represented by X. Then, the 10 bionic track monomer structures and the straight-plate spur structure are introduced into the constructed track-soil simulation system. After the simulation is completed, the resultant forces in the horizontal movement direction, i.e., the X-axis direction, of the 11 structures are derived. The maximum resultant forces in the horizontal direction, i.e., the adhesion value, are compared with those of the straight-plate spur structure. The simulated force change curves of the bionic track monomer structure IX and the straight-plate spur structure are shown in Figure 2. Fig.12 shown.

[0027] analyze Fig.12 It can be seen that the 11 bionic track monomer structures have the same trend as the simulated force change. The adhesion of the track monomer structure is shown in Table 9. The analysis shows that the bionic track monomer structure X arranged in the optimal arrangement and combination mode, that is, the bionic unit height is 3mm, the spacing is 4mm, and the two-row distribution has the best adhesion performance, with an adhesion of 6.89N. The straight plate spur structure has the worst adhesion performance, with an adhesion of 6.04N. The adhesion of the bionic track monomer structure X is 14.07% higher than that of the straight plate spur structure.

[0028] Table 9 Adhesion of the track structure

[0029] The above shows and describes the main features, methods of use, basic principles and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements according to actual conditions, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A crawler monomer structure imitating the tip of a goat's hoof, characterized in that: It includes a monomer matrix, a straight-line spur and a bionic unit structure. The bionic unit structure is obtained by stretching a bionic hoof tip curve and arranging it in an arrangement and combination manner. The bionic unit structure is arranged on the straight-line spur, wherein the bionic unit structure is placed according to the movement characteristics of the goat hoof.

2. A single body track structure imitating goat hoof tip as claimed in claim 1, characterized in that: The bionic hoof tip curve is based on the kinematic analysis conclusion of the functional parts of the goat hoof. By combining the comparison of vertical ground reaction force and vertical impulse under multiple slopes and the comparison of adhesion coefficient under multiple slopes, the action parts are determined to be the inner hoof tip of the right front hoof and the inner hoof tip of the left hind hoof, and the bionic hoof tip curve is extracted. The bionic curve satisfies the equation: y=-3.918x²+3.902x+0.01873 Among them, 0≤x≤1mm.

3. The design method of a crawler monomer structure imitating goat hoof tip as claimed in claim 1, characterized in that: The specific steps include: S1, through the comparison of vertical ground reaction force and vertical impulse under multiple slopes and adhesion under multiple slopes Coefficient comparison analysis determines the bionic prototype; S2, segmenting the hoof tip target area and extracting the external contour of the hoof tip; S3, convert the extracted hoof tip curve contour point data into coordinate information, and perform multiple The bionic curve is obtained by fitting the formula, which is used as the theoretical equation for bionic structure design. The bionic hoof tip unit structure is designed, and the bionic curve satisfies the equation: y=-3.918x²+3.902x+0.01873; S4, measure the opening angle of sheep hoof flap; S5, arranging the shoe surface pattern according to steps S3 and S4, and designing a bionic unit structure with a shoe petal opening angle on this basis; S6. According to the functional simulation method, the bionic unit structure is arranged on the straight spur as required to form a bionic hoof tip unit.

4. The crawler structure imitating goat hoof tip as claimed in claim 3, characterized in that: The bionic prototype in step S1 is the inner hoof tip of the right front hoof at a slope of 10°.

5. The crawler structure imitating goat hoof tip as claimed in claim 3, characterized in that: The specific method of step S2 is: image segmentation is achieved by marking target points, the target area of ​​the hoof tip is extracted, and contour data is obtained through grayscale, binarization, and edge detection.

6. The crawler structure imitating goat hoof tip as claimed in claim 3, characterized in that: The specific method of step S4 is: analyzing the dynamic video of the hoof opening angle of goats at a slope of 10°, extracting the frame image when the right front hoof and the left hind hoof are diagonally supported, and using an angle measurement tool to obtain that the hoof opening angle of the goat is 40°.

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