A method for optimizing the test of a bionic robot foot structure and an optimization test platform

Abstract

The present invention discloses a method for optimizing and testing a bionic robot foot structure and an optimization testing platform. It relates to the technical field of robots and includes: establishing a mathematical representation model of soil to clarify the optimal motion patterns for different terrains; building an optimization testing platform, testing the mathematical representation model of soil based on the optimal motion patterns to obtain model test data; optimizing and designing the bionic robot foot structure according to the model test data; testing the bionic robot foot structure in the optimization testing platform to capture platform test data; analyzing the platform test data to determine whether the bionic robot foot structure meets the standards. The present invention overcomes the situation that current bionic robots cannot work for a long time on complex multi-habitat terrains (sand / gravel / swamp / shoal / water surface), and at the same time provides a reasonable solution for the current situation where the design conditions of the bionic robot foot end structure are harsh and the design process is difficult.

Description

Technical Field

[0001] The present invention relates to the technical field of robots, and more particularly to an optimization test method and an optimization test platform for the foot structure of a bionic robot. Background Art

[0002] In recent years, the development of legged robots has made certain progress. Existing legged robots can already walk on flat surfaces or stairs. However, the range of motion they can achieve is still very limited, and it is still very difficult for current legged robots to walk on complex multi-habitat grounds such as muddy, swampy, or sandy areas.

[0003] According to the principle of bionics, animal feet have rich perception of the ground, and the structure of the feet to a certain extent determines the overall stability on complex terrains. Similarly, the end foot structure of a legged robot plays a crucial role in its load-bearing capacity in complex environments. However, currently, the end foot structure of legged robots is often simplified, which restricts the adaptability of these robots to complex habitat environments. At the same time, due to the lack of a suitable design optimization method for the foot structure of legged robots, there has still been little progress in the current design process of the foot end structure of legged robots.

[0004] Therefore, how to provide an optimization test method and an optimization test platform for the foot structure of a bionic robot to achieve long-term operation on complex multi-habitat terrains (sand / gravel / swamp / water surface) is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides an optimization test method and an optimization test platform for the foot structure of a bionic robot, which overcome the situation that current bionic robots cannot work long-term on complex multi-habitat terrains (sand / gravel / swamp / water surface), and at the same time provide a reasonable solution for the current situation where the design conditions of the foot end structure of bionic robots are harsh and the design process is difficult.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An optimization test method for the foot structure of a bionic robot, comprising:

[0007] Establish a soil mathematical characterization model of the bionic robot and the complex terrain, and clarify the optimal motion modes of different terrains;

[0008] Build an optimization test platform, and based on the optimal motion modes, test the soil mathematical characterization model to obtain model test data;

[0009] Optimize and design the foot structure of the bionic robot according to the model test data;

[0010] Test the bionic robot foot structure in the optimized test platform and capture the platform test data;

[0011] Analyze the platform test data to determine whether the bionic robot foot structure meets the standards;

[0012] If not, optimize it again;

[0013] If so, assemble the bionic robot according to the bionic robot foot structure.

[0014] Preferably, test the soil mathematical characterization model, including:

[0015] Test the contact force between the bionic robot's leg and feet under different motion contact trajectories with substrates of different softness, different media, and / or different viscosities, and synchronously record the contact behavior state at high speed to obtain preliminary experimental data;

[0016] Use the simple foot end of the bionic robot to test the soil mathematical characterization model and fit the optimal motion mode and preliminary experimental data.

[0017] Preferably, optimize and design the bionic robot foot structure according to the model test data, including:

[0018] Use solidworks and zbrush to jointly design the foot shape and install the foot skeleton; according to the platform test data, observe the fitting situation of the sole surface with the ground, analyze the force characteristics of real organisms, continuously iterate the design process, and make targeted improvements to the foot structure until the bionic robot reaches the desired indicators.

[0019] Preferably, install a transparent cylinder on the built optimized test platform and add sandy soil with different viscosities;

[0020] Use the robotic arm-sensor system to conduct trampling experiments on the bionic robot foot structure with different postures, different pressures, and different trajectories;

[0021] Install a camera device to photograph the entire experimental process;

[0022] The robotic arm-sensor system includes a seven-degree-of-freedom robotic arm and a six-axis force sensor.

[0023] Preferably, use the robotic arm-sensor system to conduct trampling experiments on the bionic robot foot structure with different postures, different pressures, and different trajectories;

[0024] Preferably, the trampling experiment includes:

[0025] Determine the URDF model of the robotic arm, reconstruct it using the Rviz module in ubuntu20.04, and use the moveit module to perform inverse kinematics for its trajectory planning;

[0026] Communicate the data through the ros2 topic node with the upper computer of the robotic arm;

[0027] Use the official API interface of the robotic arm to perform trajectory planning for the end effector;

[0028] Among them, the foot structure of the bionic robot is connected to the end effector of the robotic arm.

[0029] Preferably, the connection methods between the foot structure of the bionic robot and the end effector include: connection by a horizontal plate plain bearing, connection by a spherical bearing, or connection by a vertical plate plain bearing.

[0030] An optimized test platform for the foot structure of a bionic robot, comprising:

[0031] A robotic arm-sensor system, a camera device, a bearing assembly, and a foot structure of a bionic robot;

[0032] The camera device is used to photograph the entire experimental process;

[0033] The foot structure of the bionic robot is connected to the end effector of the robotic arm-sensor system through the bearing assembly.

[0034] Preferably, the foot structure of the bionic robot includes a foot prosthesis and a foot skeleton, and the foot prosthesis wraps the foot skeleton;

[0035] The foot skeleton includes: a first support portion, a second support portion, a buffer member, a force-bearing member, and a connecting member;

[0036] The first support portion is connected to the second support portion through the buffer member;

[0037] A fixing member is provided on the second support portion for nesting and fixing the foot prosthesis;

[0038] The first support portion is fixedly connected to the force-bearing member to make the force on the foot prosthesis stable;

[0039] A support member is provided on the first support portion for supporting the foot prosthesis;

[0040] The second support portion is fixedly connected to the connecting member, and the connecting member is fixedly connected to the bearing assembly.

[0041] Preferably, the connecting member includes:

[0042] A hole position for bolt connection with the bearing assembly;

[0043] A strut for inserting into the inner ring of a bearing in a bearing assembly and connecting thereto;

[0044] A groove adapted to the bearing in the bearing assembly;

[0045] A circular cut is provided on the strut for placing a first elastic washer or a second elastic washer to limit its axial position.

[0046] Preferably, the bearing assembly is a horizontal plate plain bearing assembly, a spherical plain bearing assembly or a vertical plate plain bearing assembly;

[0047] The horizontal plate plain bearing assembly includes: a first elastic washer, a first deep groove ball bearing, a first bearing outer ring retainer and a first leg connecting sheet metal;

[0048] The first elastic washer is used to engage with the circular cut of the connecting member;

[0049] The first deep groove ball bearing is placed above the first elastic washer;

[0050] The first bearing outer ring retainer secures the first deep groove ball bearing;

[0051] The first leg connecting sheet metal is fixedly connected to the first bearing outer ring retainer;

[0052] The spherical plain bearing assembly includes: a second elastic washer, a spherical plain bearing, a second bearing outer ring retainer and a second leg connecting sheet metal;

[0053] The second elastic washer is used to engage with the circular cut of the connecting member;

[0054] The spherical plain bearing is placed above the second elastic washer;

[0055] The second bearing outer ring retainer secures the spherical plain bearing;

[0056] The second leg connecting sheet metal is fixedly connected to the second bearing outer ring retainer;

[0057] The vertical plate plain bearing assembly includes: a second deep groove ball bearing, a fixing block, a baffle and a leg connecting device;

[0058] A cylinder is provided on the fixing block;

[0059] The cylinder is connected to the second deep groove ball bearing;

[0060] The leg connecting device is used to secure the second deep groove ball bearing;

[0061] The baffle passes through the cylinder and abuts against the second deep groove ball bearing;

[0062] The fixing block is fixed to the connecting member.

[0063] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a bionic robot foot structure optimization test method and an optimization test platform, including: establishing a soil mathematical characterization model of a bionic robot and complex terrain, and clarifying the optimal motion mode of different terrains; building an optimization test platform, and testing the soil mathematical characterization model based on the optimal motion mode to obtain model test data; optimizing and designing the bionic robot foot structure according to the model test data; testing the bionic robot foot structure in the optimization test platform to capture platform test data; analyzing the platform test data to determine whether the bionic robot foot structure meets the standards; if not, optimizing again; if so, assembling the bionic robot according to the bionic robot foot structure.

[0064] The present invention has the following beneficial effects: The present invention establishes a characterization method for parameters such as the medium and structural characteristics of multi-habitat targets for specific multi-habitat terrain targets (sand / swamp / shallow / water surface), providing guidance for the high adaptability, reliable stability and efficient motion control of intelligent robots in multi-habitat terrain environments. In order to test the mechanical properties of the foot structure of this new type of bionic robot, an optimized test platform based on a manipulator-sensor system is designed, and the robot's real motion gait is simulated based on speed-controllable trajectory planning, thereby obtaining a method for the mechanical performance index of the bionic robot foot prosthesis in a complex environment. For complex multi-habitat terrains, the foot structure of the bionic robot is further optimized by combining the mathematical characterization model and the data of the optimized test platform with a seven-degree-of-freedom manipulator and a six-dimensional force sensor, so that it has better carrying capacity and adaptability to complex environments than previous robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0066] Figure 1 A schematic diagram of a flow chart of an optimization test method provided in an embodiment of the present invention.

[0067] Figure 2 Schematic diagram of a foot structure optimization test platform provided in an embodiment of the present invention.

[0068] Figure 3 A schematic diagram of a foot prosthesis provided by an embodiment of the present invention.

[0069] Figure 4Schematic diagram of the foot skeleton provided by the embodiment of the present invention.

[0070] Figure 5 Exploded view of the bionic robot foot structure for pitch angle motion test provided by the embodiment of the present invention.

[0071] Figure 6 Exploded view of the bionic robot foot structure for yaw angle, pitch angle and roll angle motion tests provided by the embodiment of the present invention.

[0072] Figure 7 Exploded view of the bionic robot foot structure for yaw angle motion test provided by the embodiment of the present invention.

[0073] Among them, the sole surface 24, the first toe 19, the second toe 20, the third toe 21, the fourth toe 22, the ankle 23, the heel 25, the first vertex 40, the second vertex 41, the third vertex 42, the fourth vertex 31, the first thin column 36, the second thin column 37, the third thin column 38, the fourth thin column 39, the first arc-shaped hook 28, the second arc-shaped hook 29, the third arc-shaped hook 30, the first support part 43, the second support part 44, the first cylinder 32, the second cylinder 33, the third cylinder 34, the fourth cylinder 35, the first hole position 27, the second hole position 45, the support column 26, the groove 46, the circular ring notch 47, the first leg connecting sheet metal 6, the first deep groove ball bearing 3, the first bearing outer ring retainer 2, the first elastic washer 4, the foot skeleton 1, the foot prosthesis 5, the second leg connecting sheet metal 9, the spherical plain bearing 7, the second bearing outer ring retainer 8, the leg connecting device 12, the baffle 11, the fixing block 10, the camera device 13, the transparent cylinder 14, the sand 15, the seven-degree-of-freedom robotic arm 16, the six-axis force sensor 17, the bionic robot foot structure 18, the second elastic washer 48, the second deep groove ball bearing 49. Detailed implementation manners

[0074] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0075] An embodiment of the present invention discloses a method for optimizing and testing the foot structure of a bionic robot and an optimization testing platform. The method includes: establishing a soil mathematical characterization model of the bionic robot and complex terrains, and clarifying the optimal motion patterns for different terrains; building an optimization testing platform, and based on the optimal motion patterns, testing the soil mathematical characterization model to obtain model test data; optimizing and designing the foot structure of the bionic robot according to the model test data; testing the foot structure of the bionic robot in the optimization testing platform to capture platform test data; analyzing the platform test data to determine whether the foot structure of the bionic robot meets the standards; if not, optimizing again; if so, assembling the bionic robot according to the foot structure of the bionic robot. The embodiment of the present invention overcomes the situation that current bionic robots cannot work on complex multi-habitat terrains (sand / gravel / swamp / shoal / water surface) for a long time, and at the same time provides a reasonable solution for the current situation where the design conditions of the foot end structure of bionic robots are harsh and the design process is difficult.

[0076] Embodiment 1

[0077] This embodiment discloses a method for optimizing and testing the foot structure of a bionic robot, aiming to solve the problems of difficult design of the foot structure of current bionic robots and inability to work on complex terrains. This embodiment uses a nested iteration mode to optimize the designed product again and again, and finally design a more suitable product. As Figure 1 shown, it includes:

[0078] Step 1: Establish a soil mathematical characterization model of the bionic robot and complex terrains, and clarify the optimal motion patterns for different terrains;

[0079] Step 2: Build an optimization testing platform, and based on the optimal motion patterns, test the soil mathematical characterization model to obtain model test data;

[0080] Step 3: Optimize and design the foot structure of the bionic robot according to the model test data;

[0081] Step 4: Test the foot structure of the bionic robot in the optimization testing platform to capture platform test data; analyze the platform test data;

[0082] Step 5: Determine whether the foot structure of the bionic robot meets the standards;

[0083] If not, optimize again;

[0084] Step 6: If so, assemble the bionic robot according to the foot structure of the bionic robot.

[0085] Previous bionic robot foot-end structures did not consider the changing factors of the soil model in complex environments, resulting in overly simple foot structures that made the robots unable to adapt to complex terrains. In the embodiments of the present invention, based on the medium bearing pressure mechanical model proposed by Bekker and the shear model proposed by Janosi, considering the normal force and tangential force of the bionic robot, the bearing and shear characteristic parameters of the medium, and based on the Rankine passive earth pressure theory, the additional propulsive force provided by the soil to the circumferential surface of the foot-end is considered. The specific formulas are as follows:

[0086]

[0087] Where σ is the normal stress received by the robot, b represents the width of the contact between the crocodile robot and the soil, z is the vertical deformation of the soil, k c is the cohesion modulus of the soil, is the internal friction modulus of the soil, n represents the settlement index, and k represents the coefficient related to the bearing characteristic parameters of the soil.

[0088]

[0089] Where τ represents the tangential force received by the robot, c represents the soil cohesion, is the internal friction angle of the soil.

[0090] Select medium samples when the multi-functional robot is working, and measure the soil shear characteristic parameters, including the cohesion c and the internal friction angle Use devices such as a Benkelman beam to measure the bearing characteristic parameters k c , and n of the soil. Use pressure sensors and other devices to measure the pressure and tangential force between the robot and the soil.

[0091] Establish a soil mathematical representation model for the multi-functional robot and complex terrains, and clarify the optimal motion modes for different multi-functional terrain targets (sand / gravel / marsh / shoal / water surface). The purpose of this step is to conduct scientific mathematical modeling for the environment where the bionic robot needs to work, so that the design process can be quantified.

[0092] Specifically, test the soil mathematical representation model, including:

[0093] Test the contact force between the bionic robot's leg feet and different softness, different media, and / or different viscosity bases under different motion contact trajectories, and synchronously record the contact behavior state at high speed to obtain preliminary experimental data;

[0094] Use the simple foot-end of the bionic robot to test the soil mathematical representation model, and fit the optimal motion mode and the preliminary experimental data.

[0095] This process is to verify the accuracy and generality of the model. In the embodiments of the present invention, tests are carried out by optimizing the six-axis force sensor of the test platform. The contact forces between the bionic robot's leg feet and substrates with different softness, different media, and different viscosities under different motion contact trajectories include viscous forces, supporting forces, propulsive forces, etc. By synchronously and rapidly recording the contact behavior states, the self-adaptive operation mechanism of the foot tip trajectory for different environments is revealed, which is used to optimize the contact leg foot structure and motion operation trajectory of the bionic robot. The soil mathematical characterization model is tested using simple foot tips of the bionic robot (such as flat foot tips, concave plate foot tips, convex plate foot tips). The optimal motion mode and the preliminary experimental data results are fitted to determine the correctness of the soil model and establish a correct design guideline. Among them, the bionic robot can be a bionic ridge-leg robot.

[0096] Specifically, the foot structure of the bionic robot is optimized and designed according to the model test data, including:

[0097] The foot shape is designed jointly using solidworks and zbrush and the foot skeleton is arranged; according to the platform test data, the fitting situation of the sole surface and the ground is observed, the force characteristics of real organisms are analyzed, and the design process is continuously iterated. Targeted improvements are made to the foot structure until the bionic robot reaches the expected indicators.

[0098] In the embodiments of the present invention, the foot structure of the bionic robot is optimized in combination with the model test data, and the model of the foot tip structure of the bionic robot is continuously designed, so that the foot structure is closer to the foot tip of real animals and has excellent mechanical properties. This step begins to truly design the robot's foot. The foot shape is designed jointly using solidworks and zbrush, and a suitable foot skeleton is arranged. Since there is a rigid-flexible coupling phenomenon between the foot skeleton and the foot prosthesis and the mechanical characteristics are non-linear, the design process is relatively complex. Therefore, its indicators need to be optimized iteratively through continuous experiments. According to the judgment conditions in step 5, the design process is continuously iterated. According to the platform test data, the fitting situation of the sole surface and the ground is observed, the force characteristics of real organisms are analyzed, and finally a finished product with the best mechanical properties is presented.

[0099] Specifically, a transparent cylinder 14 is arranged on the built optimization test platform, and sandy soil 15 with different viscosities is added therein;

[0100] The mechanical arm-sensor system is used to conduct trampling experiments on the foot structure of the bionic robot with different postures, different pressures, and different trajectories;

[0101] A camera device 13 is placed to photograph the entire experimental process;

[0102] The robotic arm-sensor system includes a seven-degree-of-freedom robotic arm 16 and a six-axis force sensor 17.

[0103] Specifically, the robotic arm-sensor system is used to conduct stepping experiments on the foot structure of the bionic robot with different postures, different pressures, and different trajectories.

[0104] Specifically, the stepping experiment includes:

[0105] Determine the URDF model of the robotic arm, reconstruct it using the Rviz module in ubuntu20.04, and use the moveit module to solve the inverse kinematics of its trajectory planning;

[0106] Transmit the data through the ros2 topic node to communicate with the upper computer of the robotic arm;

[0107] Use the official API interface of the robotic arm to conduct trajectory planning for the end effector;

[0108] Among them, the foot structure 18 of the bionic robot is connected to the end effector of the robotic arm.

[0109] Specifically, the connection methods between the foot structure 18 of the bionic robot and the end effector include: connection by a horizontal plate plain bearing, connection by a spherical bearing, or connection by a vertical plate plain bearing.

[0110] In the embodiment of the present invention, the foot structure-environment interaction contact behavior test of the bionic robot is carried out on the built optimization test platform, and the foot structure is tested using the seven-degree-of-freedom robotic arm 16 and the six-axis force sensor 17; as Figure 2As shown in the figure, a transparent cylinder 14 is placed on the built optimization test platform, and sands 15 with different viscosities are added therein. The mechanical arm is used to perform trampling experiments with different postures, different pressures, and different trajectories; and a high-speed camera device 13 is placed around to photograph the entire experimental process, and a series of data and indicators are obtained through the high-speed camera device 13 and the six-axis force sensor 17. This step requires the use of a seven-degree-of-freedom mechanical arm 16 and a six-axis force sensor 17. First, the URDF model of the mechanical arm needs to be determined, and it is reconstructed using the Rviz module in ubuntu20.04. The inverse solution of its trajectory planning is obtained using the moveit module. The data is communicated with the upper computer of the mechanical arm through the ros2 topic node, and the NURBS trajectory planning with controllable speed for the end effector can be carried out using the official API interface of the mechanical arm. The six-axis force sensor 17 and the high-speed camera device 13 record the captured data for subsequent further quantitative analysis. At this time, the bionic robot foot structure 18 is connected to the end effector of the mechanical arm. The embodiment of the present invention designs 3 connection methods, namely the horizontal plate plain bearing connection method, the spherical bearing connection method, and the vertical plate plain bearing connection method. The purpose of doing this is to respectively judge which scheme has the best effect when giving degrees of freedom in different directions. As Figure 2 The foot structure shown allows the rotational degree of freedom of the pitch angle.

[0111] In the embodiment of the present invention, step 5 is a judgment module, similar to the while function. According to the data and indicators obtained in step 4, combined with the force characteristics of real organisms and the finite element analysis of the bionic robot foot end structure (in the embodiment of the present invention, a crocodile is taken as an example, combined with the force characteristics of real crocodiles and the expected indicators of the bionic crocodile robot), by observing the images captured by the high-speed camera device 13, the fitting situation between the sole surface 24 and the sands 15 is analyzed to judge whether the foot structure reaches the ideal performance. If the expected performance index is not reached, it returns to step 3 for further optimization. If the expected performance index is reached, it enters step 6 to ensure the reliability of the designed structure through repeated iterations and tests.

[0112] In the embodiment of the present invention, step 6 is to perform fitting and assembly on the feet of the bionic robot, and use the designed finished product to improve the overall load-bearing capacity of the robot, so that it can have better motion performance in complex multi-habitat terrains. According to the new bionic robot foot structure optimization design process provided by the embodiment of the present invention, a foot prosthesis model that allows the robot to work in complex terrains will be obtained (as Figure 3 shown).

[0113] Embodiment 2

[0114] An optimization test platform for a bionic robot foot structure, asFigure 2 As shown, it includes:

[0115] A robotic arm - sensor system, a camera device 13, a bearing assembly, and a bionic robot foot structure 18;

[0116] The camera device 13 is used to photograph the entire experimental process;

[0117] The bionic robot foot structure 18 is connected to the end effector of the robotic arm - sensor system through a bearing assembly.

[0118] Specifically, the bionic robot foot structure 18 includes a foot prosthesis and a foot skeleton, and the foot prosthesis wraps the foot skeleton;

[0119] The foot skeleton includes: a first support part 43, a second support part 44, a buffer, a force - receiving part, and a connecting part;

[0120] The first support part 43 is connected to the second support part 44 through the buffer;

[0121] A fixing part is arranged on the second support part 44 for nesting and fixing the foot prosthesis;

[0122] The first support part 43 is fixedly connected to the force - receiving part to make the force on the foot prosthesis stable;

[0123] A support part is arranged on the first support part 43 for supporting the foot prosthesis;

[0124] The second support part 44 is fixedly connected to the connecting part, and the connecting part is fixedly connected to the bearing assembly.

[0125] The bionic ridge - leg robot foot prosthesis provided by the embodiment of the present invention has a total of 1074 triangular parting surfaces, aiming to simulate the foot surface of real amphibious ridge - leg organisms with a large number of parting surfaces. As Figure 3 shown, the part with the largest force is the sole surface 24. The sole surface 24 is connected to the toes. The toes include a first toe 19, a second toe 20, a third toe 21, and a fourth toe 22. Above the sole surface 24 is the ankle 23, and the heel 25 plays a supporting role. Each parting surface is optimized and rolled according to the foot structure optimization design method, and it has excellent load - bearing capacity in complex terrains. The foot prosthesis can be made of silicone or resin - like materials to imitate the texture of the foot muscles of real animals.

[0126] According to the foot prosthesis of the bionic ridge-leg robot provided by the embodiment of the present invention, the foot skeleton is redesigned. It is proposed to use ABS or nylon fiber-reinforced 7200 material, which ensures a certain degree of hardness and toughness of the foot skeleton, allows twisting and bending to different degrees, and can also protect the entire foot prosthesis.

[0127] Specifically, the connecting member includes:

[0128] A hole position for bolt connection with the bearing assembly;

[0129] A pillar 26 for inserting into the inner ring of the bearing in the bearing assembly and connecting with it;

[0130] A groove 46, and the groove is adapted to the bearing of the bearing assembly;

[0131] A circular ring notch 47 is provided on the pillar for placing the first elastic washer 4 or the second elastic washer 48 to limit its axial position.

[0132] As Figure 4 shown, the foot skeleton provided by the embodiment of the present invention is in an overall tetrahedral shape, similar to a pyramid. The four points of the first vertex 40, the second vertex 41, the third vertex 42, and the fourth vertex 31 are the vertices of the tetrahedron, ensuring the stability of force application. Inside the foot skeleton, there is a support member, and the support member includes the first thin column 36, the second thin column 37, the third thin column 38, and the fourth thin column 39. The support member extends deep into the toes of the foot prosthesis to provide a certain supporting effect for the toes, and at the same time, there is a certain gap to ensure the smooth progress of the casting process. The buffer member is located at the fourth vertex 31 and is an arc-shaped turning part at the bottom of the bracket, which can play a certain buffering role when the sole is stressed. The fixing member is composed of a variety of arc-shaped hooks, including the first arc-shaped hook 28, the second arc-shaped hook 29, and the third arc-shaped hook 30, which can better fasten the foot prosthesis to prevent it from falling. The force-bearing member is located at the main force-bearing part of the sole, at the bottom of the sole. Also, because the maximum force-bearing point during the walking of the amphibious ridge-leg creature is at the proximal part of the foot, the first support part 43 of the foot skeleton is fixedly connected to the force-bearing member. The force-bearing member includes the first cylinder 32, the second cylinder 33, the third cylinder 34, and the fourth cylinder 35. The first cylinder 32, the second cylinder 33, the third cylinder 34, and the fourth cylinder 35 are cylinders with unequal lengths, ensuring stable force application. The hole positions of the connecting member can be two: the first hole position 27 and the second hole position 45; the first hole position 27 and the second hole position 45 are responsible for bolt connection with the fixing block 10 in the bearing assembly. The middle pillar 26 is used to connect the bearing assembly. The pillar 26 is inserted into the inner ring of the bearing. The lower groove 46 is used to carry the outer ring of the bearing. The circular ring notch 47 provided on the pillar is used to place the elastic washer to hold the position of the bearing.

[0133] According to the bionic robot foot prosthesis and the bionic robot foot skeleton, a suitable interface is required for the motion test in combination with the robotic arm-six-axis force sensor system. Three types of bearing components are designed in the embodiments of the present invention, namely, a horizontal plate plain bearing component (as shown in Figure 7 ), a spherical plain bearing component (as shown in Figure 6 ), and a vertical plate plain bearing component (as shown in Figure 5 ), to test the force conditions of different degrees of freedom, so as to optimize the scheme again.

[0134] Specifically, the bearing component is a horizontal plate plain bearing component, a spherical plain bearing component or a vertical plate plain bearing component;

[0135] The horizontal plate plain bearing component includes: a first elastic washer 4, a first deep groove ball bearing 3, a first bearing outer ring retainer 2, and a first leg connecting sheet metal 6;

[0136] The first elastic washer 4 is used to clamp the circular ring notch 47 of the connecting piece;

[0137] The first deep groove ball bearing 3 is placed above the first elastic washer 4;

[0138] The first bearing outer ring retainer 2 fixes the first deep groove ball bearing 3;

[0139] The first leg connecting sheet metal 6 is fixedly connected to the first bearing outer ring retainer 2.

[0140] As shown in Figure 7 , in the embodiments of the present invention, the motion test for supporting the yaw angle includes: a first leg connecting sheet metal 6 connected to the hip of the bionic ridge-legged robot, a first bearing outer ring retainer 2 for fixing the first deep groove ball bearing 3, a first elastic washer 4 for adjusting the position of the first deep groove ball bearing, a bionic ridge-legged robot foot skeleton 1, and a bionic ridge-legged robot foot prosthesis 5.

[0141] This scheme is a horizontal plate plain bearing type scheme. First, the first elastic washer 4 is clamped at the circular ring notch 47 on the foot skeleton 1, and then a plain deep groove ball bearing 3 with an inner diameter of 8 mm is placed from above. The first bearing outer ring retainer 2 clamps the outer ring of the first deep groove ball bearing 3 and clamps it tightly. The first leg connecting sheet metal 6 forms an angle of 18° and is connected to the first bearing outer ring retainer 2 with bolts. Corresponding holes are left on the first bearing outer ring retainer 2 for installing a tension spring to make the whole robot foot have flexibility. Both the first deep groove ball bearing and the second deep groove ball bearing 49 are plain deep groove ball bearings.

[0142] The spherical plain bearing component includes: a second elastic washer 48, a spherical plain bearing 7, a second bearing outer ring retainer 8, and a second leg connecting sheet metal 9;

[0143] The second elastic washer 48 is used to clamp the circular ring notch of the connecting piece;

[0144] The spherical eye bearing 7 is placed above the second elastic washer 48;

[0145] The second bearing outer ring retainer 8 fixes the spherical eye bearing 7;

[0146] The second leg connecting sheet metal 9 is fixedly connected to the second bearing outer ring retainer 8.

[0147] As Figure 6 shown, in the embodiment of the present invention, the movement tests of yaw, pitch, and roll angles are supported: including: the second leg connecting sheet metal 9 connected to the hip of the bionic ridge leg robot, the second bearing outer ring retainer 8 for fixing the spherical eye bearing 7, the second elastic washer 48 for adjusting the position of the spherical eye bearing, the bionic ridge leg robot foot skeleton 1, and the bionic ridge leg robot foot prosthesis 5. This solution is a spherical eye bearing type solution. First, the second elastic washer 48 is clamped at the circular ring notch 47 on the foot skeleton 1, and then the spherical eye bearing 7 with an inner diameter of 8 mm is placed from above. The second bearing outer ring retainer 8 clamps the bearing outer ring of the spherical eye bearing 7 and clamps it tightly. The second leg connecting sheet metal 9 forms an included angle of 18° and is bolted to the second bearing outer ring retainer 8. Corresponding holes are provided on the second bearing outer ring retainer 8, and a tension spring can be installed to make the whole robot foot flexible.

[0148] The vertical plate plain bearing assembly includes: a second deep groove ball bearing 49, a fixing block 10, a baffle 11, and a leg connecting device 12;

[0149] A cylinder is provided on the fixing block 10;

[0150] The cylinder is connected to the second deep groove ball bearing 49;

[0151] The leg connecting device 12 is used to fix the second deep groove ball bearing 49;

[0152] The baffle 11 passes through the cylinder and abuts against the second deep groove ball bearing 49;

[0153] The fixing block 10 is fixed to the connecting piece.

[0154] As Figure 5As shown, in an embodiment of the present invention, motion testing of pitch angle is supported: including: a leg connecting device 12 connected to the hip of the bionic spine-legged robot, a baffle 11 for adjusting the position of the second deep groove ball bearing 49, a fixing block 10 for fixing the second deep groove ball bearing 49 and clamping the foot skeleton of the bionic spine-legged robot, a bionic spine-legged robot foot skeleton 1 and a bionic spine-legged robot foot prosthesis 5; the leg connecting device 12 is also used to fix the second deep groove ball bearing 49; this scheme is a vertical plane bearing scheme, the second deep groove ball bearing 49 with an inner diameter of 8mm is inserted into the cylinder on the fixing block 10, and then the leg connecting device 12 is buckled to the second deep groove ball bearing 49, and a 2mm hole is left above it for clamping the second deep groove ball bearing 49, and the overall slope is 18°, which is a suitable angle tested according to the bionic robot foot structure design process provided by the present invention. The baffle 11 is then inserted into the cylinder to resist the position of the second deep groove ball bearing 49 so that it does not produce axial displacement. A groove is left on the leg connecting device 12 and the fixing block 10, and a tension spring can be installed to make the entire robot foot compliant.

[0155] The bionic spine-legged robot foot structure provided by the embodiment of the present invention is composed of a bionic spine-legged robot foot skeleton designed by the method and a bionic spine-legged robot foot prosthesis designed by the method. The bionic spine-legged robot foot prosthesis is designed with a total of 1074 parting surfaces, each of which is optimized through testing and iteration according to the method of the present invention. After repeated testing, it has a better load-bearing effect than previous bionic robot foot prostheses, and solves the problem that previous bionic robots cannot work in complex terrain.

[0156] The overall shape of the bionic spine leg robot foot skeleton is a triangular pyramid, and the pyramid-like structure can ensure its load-bearing capacity. After Abaqus analysis of its stress-intensive points, improvements are made based on the stress analysis diagram. In order to ensure that the bionic spine leg robot foot prosthesis can fully wrap the skeleton, the foot skeleton is designed with many protruding structures, which embrace the prosthesis like human ribs to prevent it from falling off during movement. The 3D curve profile of the toe part is quantitatively designed according to the distribution of the prosthetic toe, so that the toe part of the foot skeleton can be just inserted into the toe of the foot prosthesis.

[0157] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0158] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An optimization test method for the foot structure of a bionic robot, characterized in that, Including: Establish a soil mathematical characterization model for the bionic robot and complex terrain, and clarify the optimal motion patterns for different terrains; Build an optimization test platform, and based on the optimal motion pattern, test the soil mathematical characterization model to obtain model test data; Optimize and design the foot structure of the bionic robot according to the model test data; Test the foot structure of the bionic robot in the optimization test platform to capture platform test data; Analyze the platform test data to determine whether the foot structure of the bionic robot meets the standards; If not, optimize again; If so, assemble the bionic robot according to the foot structure of the bionic robot; The foot structure of the bionic robot includes a foot prosthesis and a foot skeleton, and the foot prosthesis wraps the foot skeleton; The foot skeleton includes: a first support part, a second support part, a buffer, a force-bearing part, and a connecting part; The first support part is connected to the second support part through the buffer; A fixing part is arranged on the second support part for nesting and fixing the foot prosthesis; The first support part is fixedly connected to the force-bearing part to make the force on the foot prosthesis stable; A support part is arranged on the first support part for supporting the foot prosthesis; The second support part is fixedly connected to the connecting part, and the connecting part is fixedly connected to the bearing assembly; The connecting part includes: A hole position for bolt connection with the bearing assembly; A pillar for inserting into the inner ring of the bearing in the bearing assembly and connecting with it; A groove, and the groove is adapted to the bearing of the bearing assembly; A circular cut is provided on the pillar for placing a first elastic washer or a second elastic washer to limit its axial position; Optimize and design the foot structure of the bionic robot according to the model test data, including: Use solidworks and zbrush to jointly design the foot shape and place the foot skeleton; according to the platform test data, observe the fitting situation of the sole surface with the ground, analyze the force characteristics of real organisms, continuously iterate the design process, and make targeted improvements to the foot structure until the bionic robot reaches the expected indicators; Place a transparent cylinder on the built optimization test platform and add sandy soil with different viscosities; Use a robotic arm-sensor system to conduct trampling experiments on the foot structure of the bionic robot with different postures, different pressures, and different trajectories; Place a camera device to photograph the entire experimental process; The robotic arm-sensor system includes a seven-degree-of-freedom robotic arm and a six-axis force sensor.

2. The optimized test method for the foot structure of a bionic robot according to claim 1, characterized in that Test the soil mathematical characterization model, including: Test the contact force between the walking legs of the bionic robot and the substrates with different softness, different media, and / or different viscosities under different motion contact trajectories, and synchronously record the contact behavior state at high speed to obtain preliminary experimental data; Use the simple foot end of the bionic robot to test the soil mathematical characterization model and fit the optimal motion pattern and preliminary experimental data.

3. The optimized test method for the foot structure of a bionic robot according to claim 1, characterized in that Use a robotic arm-sensor system to conduct trampling experiments on the foot structure of the bionic robot with different postures, different pressures, and different trajectories.

4. The optimized test method for the foot structure of a bionic robot according to claim 3, characterized in that, The connection methods between the bionic robot foot structure and the end effector include: horizontal plate plain bearing connection, fish-eye bearing connection or vertical plate plain bearing connection.

5. A bionic robot foot structure optimization test platform, which is applied to the bionic robot foot structure optimization test method described in any one of claims 1-4, and is characterized in that, Including: A robotic arm-sensor system, a camera device, a bearing assembly, and a bionic robot foot structure; The camera device is used to photograph the entire experimental process; The bionic robot foot structure is connected to the end effector of the robotic arm-sensor system through a bearing assembly.

6. The optimized test platform for the foot structure of a bionic robot according to claim 5, characterized in that, The bearing assembly is a horizontal plate plain bearing assembly, a fish-eye bearing assembly or a vertical plate plain bearing assembly; The horizontal plate plain bearing assembly includes: a first elastic washer, a first deep groove ball bearing, a first bearing outer ring retainer, and a first leg connection sheet metal; The first elastic washer is used to clamp the circular notch of the connecting piece; The first deep groove ball bearing is placed above the first elastic washer; The first bearing outer ring retainer fixes the first deep groove ball bearing; The first leg connection sheet metal is fixedly connected to the first bearing outer ring retainer; The fish-eye bearing assembly includes: a second elastic washer, a fish-eye bearing, a second bearing outer ring retainer, and a second leg connection sheet metal; The second elastic washer is used to clamp the circular notch of the connecting piece; The fish-eye bearing is placed above the second elastic washer; The second bearing outer ring retainer fixes the fish-eye bearing; The second leg connection sheet metal is fixedly connected to the second bearing outer ring retainer; The vertical plate plain bearing assembly includes: a second deep groove ball bearing, a fixing block, a baffle, and a leg connection device; A cylinder is provided on the fixing block; The cylinder is connected to the second deep groove ball bearing; The leg connection device is used to fix the second deep groove ball bearing; The baffle passes through the cylinder and abuts against the second deep groove ball bearing; The fixing block is fixed to the connecting piece.

Images