Lightweight design and manufacturing method for legs of quadruped robot

Abstract

The invention discloses a lightweight design and manufacturing method for legs of a quadruped robot, relates to the technical field of lightweight design and manufacturing, realizes common optimization of multiple targets, can meet lightweight design of leg structures of the quadruped robot, reduces the weight of the leg structures, and improves the reliability of the leg structures. And meanwhile, the movement capacity of the quadruped robot in the field complex environment can be improved through design, compared with a traditional design mode, the design process is simple and reliable, the design flexibility is high, compared with a traditional manufacturing mode, the manufacturing process is simplified, the part manufacturing efficiency is improved, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of lightweight design and manufacturing, and in particular to a lightweight design and manufacturing method for the legs of a quadruped robot. Background Art

[0002] The mass of a quadruped robot's legs has a great impact on its mobility. The existing manufacturing method for quadruped robot legs mainly relies on traditional subtractive processing methods. Therefore, the design of the quadruped robot leg structure is limited by traditional processing methods. The structure used is basically a traditional rib-plate structure with a large overall weight, which makes it difficult to improve the moving speed or other mobility capabilities.

[0003] Most existing quadruped robot leg structures are designed with a hollow design with a large space on the outside to reduce weight. Weight is reduced by removing materials, which is not conducive to quadruped robots walking in outdoor mud or water environments. They are easily filled with mud and other debris, increasing the weight, resulting in reduced mobility or even loss of mobility.

[0004] The existing scheme is designed based on traditional machining technology. The design is affected by traditional machining and has many limiting factors. The general design and manufacturing process is as follows: preliminary analysis of the operating conditions and load-bearing conditions of the quadruped robot -> static and dynamic simulation -> structural design and weight reduction design combined with machining technology -> simulation verification of its performance -> physical test.

[0005] It can be seen that the methods for calculating the leg quality of quadruped robots in the prior art have the following disadvantages:

[0006] Existing design methods can only reduce weight through local thinning, external space hollowing out and material removal, and the design methods are limited to traditional processing methods.

[0007] Traditional machining methods make it difficult to process closed internal cavity structures or other complex lightweight structures, while traditional methods such as casting and welding have long processing processes and low comprehensive mechanical properties, making it difficult to meet the requirements of lightweight and high-strength legs.

[0008] The materials used in traditional processing methods are mostly plates, and it is difficult to improve the performance of the required parts by adjusting the material composition according to the performance requirements of the parts. Summary of the invention

[0009] In view of the above problems, the present invention provides a method for designing and manufacturing a lightweight quadruped robot leg to overcome the above problems or at least partially solve the above problems. The method solves the problem that it is difficult to significantly reduce the weight and improve the adaptability to complex environments in the current design and manufacturing process of traditional quadruped robot legs. The method realizes the design and manufacturing of a lightweight structure of a quadruped robot leg to meet the requirements of high mobility of the quadruped robot in complex environments.

[0010] The present invention provides the following scheme:

[0011] A lightweight design and manufacturing method for a quadruped robot leg, comprising:

[0012] According to the leg structure connection mode, the leg joint control device structure and the quadruped robot motion posture, the designed quadruped robot leg structure is divided into leg structure lightweight design space and non-design space;

[0013] Taking external loads and force conditions of the legs in different motion postures as constraints, and taking weight and maximum stress as optimization targets, a topological optimization design is performed on the lightweight design space of the leg structure to obtain a first design model;

[0014] Shelling the first design model, retaining the target wall thickness, with the interior being a hollow cavity, to generate a second design model of a closed leg structure;

[0015] Adding a reinforcing rib plate parallel to the vertical direction inside the cavity of the second design model, and adding a face lattice on the inner wall of the cavity to obtain a third design model;

[0016] The third design model is subjected to dynamic and static simulation analysis using finite element analysis software to obtain simulation results; the wall thickness of different areas of the calf structure and the non-uniform weight-reducing structural distribution of the middle reinforcing rib plate are optimized using the simulation results as input, and the non-uniform surface lattice structure of the inner wall surface of the hollow cavity is optimized using a variable density method to obtain a target design model;

[0017] Slicing and process planning the target design model by computer software to obtain a target printing model;

[0018] Selective laser melting technology is used, and lightweight metal powder materials with optimized composition are used as raw materials for parts processing. The file corresponding to the target printing model is imported into the additive equipment to complete the integrated manufacturing of parts.

[0019] Preferably, the non-uniform weight-reducing structure comprises non-uniform weight-reducing holes.

[0020] Preferably: according to the requirements of the quadruped robot leg structure on the comprehensive mechanical properties of the material, the composition of the existing lightweight metal powder material is regulated, and the comprehensive mechanical properties of the material are improved by adding strengthening elements to obtain the lightweight metal powder material with optimized composition.

[0021] Preferably, the existing lightweight metal powder material includes any one of aluminum alloy and titanium alloy.

[0022] A lightweight leg structure, characterized in that it includes a closed leg structure body manufactured by adopting the above-mentioned lightweight design and manufacturing method for the legs of a quadruped robot, the interior of the closed leg structure body has a hollow cavity structure, a lightweight reinforcing rib plate with a non-uniform weight reduction structure is arranged in the hollow cavity structure, and the surface of the hollow cavity structure includes a non-uniform surface lattice reinforcement structure.

[0023] A quadruped robot comprises the above-mentioned lightweight leg structure.

[0024] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0025] A lightweight design and manufacturing method for the legs of a quadruped robot provided in an embodiment of the present application achieves joint optimization of multiple objectives, can meet the lightweight design of the leg structure of the quadruped robot, reduce the weight of the leg structure, and at the same time, the design can improve the movement ability of the quadruped robot in complex outdoor environments. Compared with traditional design methods, its design process is simple and reliable, and the design flexibility is high. Compared with traditional manufacturing methods, its manufacturing process is simplified, which improves the manufacturing efficiency of parts and reduces costs.

[0026] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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 are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a flow chart of a method for lightweight design and manufacturing of a quadruped robot leg provided by an embodiment of the present invention;

[0029] Figure 2 is a schematic diagram of the appearance structure of the leg provided by an embodiment of the present invention;

[0030] Figure 3It is a schematic diagram of the lattice structure on the wall of the closed leg hollow cavity provided by an embodiment of the present invention;

[0031] Figure 4 It is a schematic diagram of the structure of lightweight reinforcing ribs added to the hollow inner cavity of the closed leg provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0033] See also Figure 1 , is a lightweight design and manufacturing method for a quadruped robot leg provided by an embodiment of the present invention, such as Figure 1 As shown, the method may include:

[0034] According to the leg structure connection mode, the leg joint control device structure and the quadruped robot motion posture, the designed quadruped robot leg structure is divided into leg structure lightweight design space and non-design space;

[0035] Taking external loads and force conditions of the legs in different motion postures as constraints, and taking weight and maximum stress as optimization targets, a topological optimization design is performed on the lightweight design space of the leg structure to obtain a first design model;

[0036] Shelling the first design model, retaining the target wall thickness, with the interior being a hollow cavity, to generate a second design model of a closed leg structure;

[0037] Adding a reinforcing rib plate parallel to the vertical direction inside the cavity of the second design model, and adding a face lattice on the inner wall of the cavity to obtain a third design model;

[0038] The third design model is subjected to dynamic and static simulation analysis using finite element analysis software to obtain simulation results; the wall thickness of different areas of the calf structure and the non-uniform weight-reducing structural distribution of the middle reinforcing rib plate are optimized using the simulation results as input, and the non-uniform surface lattice structure of the inner wall surface of the hollow cavity is optimized using a variable density method to obtain a target design model;

[0039] Slicing and process planning the target design model by computer software to obtain a target printing model;

[0040] Selective laser melting technology is used, and lightweight metal powder materials with optimized composition are used as raw materials for parts processing. The file corresponding to the target printing model is imported into the additive equipment to complete the integrated manufacturing of parts.

[0041] Furthermore, in a specific implementation, the non-uniform weight reduction structure may include non-uniform weight reduction holes.

[0042] Furthermore, according to the requirements of the quadruped robot leg structure on the comprehensive mechanical properties of the material, the composition of the existing lightweight metal powder material is adjusted, and the comprehensive mechanical properties of the material are improved by adding strengthening elements to obtain the lightweight metal powder material with optimized composition. The existing lightweight metal powder material includes any one of aluminum alloy and titanium alloy.

[0043] The lightweight design and manufacturing method for the legs of a quadruped robot provided in the embodiments of the present application can realize the forming of parts of any complex shape by using additive manufacturing technology, which can meet the integrated manufacturing requirements of the leg structure of a quadruped robot. Compared with traditional processing, the process is simple and efficient, and the material composition can be adjusted according to the performance requirements of the parts, thereby improving the performance of the required parts and reducing the weight. Compared with traditional design methods, the lightweight design method for parts based on the advantages of additive manufacturing technology expands the design ideas of parts, and can greatly reduce the weight of the leg structure of a quadruped robot by using complex curved surface structures or lattice structures.

[0044] The embodiment of the present application provides a method for lightweight design and simulation of the legs of a quadruped robot under complex working conditions. Multiple constraints such as different motion postures of the legs of the quadruped robot, leg degrees of freedom, application of external cyclic loads, stress conditions of the overall structure, and service life are simultaneously applied, and the existing topology optimization algorithm and statics and dynamics simulation algorithms are combined to generate a closed leg lightweight structure with an inner cavity.

[0045] Taking the overall stress condition and weight of the leg structure as the optimization goal, combined with dynamic and static simulation analysis, a variable density design method is used to add face lattices on the inner wall of the leg to improve the mechanical properties of the leg, reduce the overall wall thickness of the leg structure, and reduce the weight.

[0046] Due to the complex stress conditions of the leg structure during movement, lightweight reinforcing ribs are added to the internal cavity of the leg structure to better meet the complex operating conditions. Non-uniform weight-reducing structures are distributed on the reinforcing ribs to reduce the weight as much as possible while meeting the mechanical properties.

[0047] Combining existing additive manufacturing lightweight materials, by adding appropriate strengthening elements to the original metal powder components, a strengthening phase is formed to improve the overall comprehensive mechanical properties of parts.

[0048] The use of additive manufacturing integrated forming solves the problem of complex inner cavity structures and lattice structures that are difficult to process using traditional processing methods.

[0049] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 1 This is a flow chart of the lightweight design and manufacturing method of the legs of a quadruped robot. Figure 2-Figure 4 This is a schematic diagram of the lightweight structure of the leg, where: Figure 2 For the leg shape structure, Figure 3 It is a lattice structure on the hollow inner wall of the closed leg. Figure 4 Lightweight reinforcement rib structure added to the closed leg hollow cavity.

[0050] This application proposes a lightweight design and manufacturing method for the legs of a quadruped robot, and the specific implementation methods are as follows:

[0051] S1: The leg structure of the quadruped robot designed by the traditional method is processed, and the leg structure connection method, the leg joint control device structure and the quadruped robot motion posture are comprehensively considered. The leg structure lightweight design space and non-design space are divided, and other space structures other than the joint connection structure characteristics are used as the leg lightweight design space.

[0052] S2: Taking the external load and the force conditions of the legs in different motion postures as constraints, and taking the weight and maximum stress as optimization targets, a topological optimization design is performed to obtain the first design model A1.

[0053] S3: Shell the first design model A1, retain a certain wall thickness, and form a hollow cavity inside, thereby generating a second design model A2 of a closed leg structure.

[0054] S4: Inside the cavity of the second design model A2, a reinforcing rib plate parallel to the vertical direction is added, and a face lattice is added on the inner wall of the cavity. Through these two methods, the mechanical properties of the second design model A2 are enhanced, and the wall thickness of the leg structure is reduced to further reduce the weight, thereby obtaining the third design model A3.

[0055] S5: The third design model A3 was simulated in dynamics and statics using finite element analysis software. The wall thickness in different areas of the calf structure and the non-uniform weight-reducing structural distribution of the middle reinforcing rib plate were optimized using the simulation results. The surface lattice structure on the inner wall of the cavity was optimized using the variable density method to obtain the final target design model A4.

[0056] S6: According to the requirements of the quadruped robot leg structure on the comprehensive mechanical properties of materials, the composition of existing lightweight metal powder materials is adjusted, and appropriate strengthening elements are added to improve the comprehensive mechanical properties of materials.

[0057] S7: Slice and process plan the designed target design model A4 through computer software to obtain the final target printing model.

[0058] S8: Selective laser melting technology is used to take lightweight metal powder materials with optimized composition as raw materials for parts processing. The planned target printing model files are imported into the equipment to complete the final integrated manufacturing of parts.

[0059] Among them, the choice of lightweight metal materials is mainly aluminum alloy and titanium alloy, which have the characteristics of light weight and high strength. After composition adjustment, the comprehensive mechanical properties can be further improved.

[0060] The internal cavity of the closed leg structure can be optimized for different lightweight rib designs and variable-density surface lattice designs based on different operating conditions and load conditions, targeting weak parts. The design is highly flexible and can reduce the weight of the leg structure to the greatest extent while meeting different operating conditions and load conditions, thereby avoiding weight redundancy.

[0061] In summary, the lightweight design and manufacturing method of the quadruped robot legs provided in this application realizes the joint optimization of multiple objectives, can meet the lightweight design of the leg structure of the quadruped robot, reduce the weight of the leg structure, and at the same time, the design can improve the movement ability of the quadruped robot in complex outdoor environments. Compared with traditional design methods, its design process is simple and reliable, and the design flexibility is high. Compared with traditional manufacturing methods, its manufacturing process is simplified, which improves the manufacturing efficiency of parts and reduces costs.

[0062] The embodiment of the present application can also provide a lightweight leg structure, including a closed leg structure body manufactured by the above-mentioned quadruped robot leg lightweight design and manufacturing method, the interior of the closed leg structure body has a hollow cavity structure, a lightweight reinforcing rib plate with a non-uniform weight reduction structure is arranged in the hollow cavity structure, and the surface of the hollow cavity structure includes a non-uniform surface lattice reinforcement structure.

[0063] The embodiment of the present application may also provide a quadruped robot, comprising the above-mentioned lightweight leg structure.

[0064] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0065] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0066] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A lightweight design and manufacturing method for the legs of a quadruped robot, characterized in that: include: According to the leg structure connection mode, the leg joint control device structure and the quadruped robot motion posture, the designed quadruped robot leg structure is divided into leg structure lightweight design space and non-design space; Taking external loads and force conditions of the legs in different motion postures as constraints, and taking weight and maximum stress as optimization targets, a topological optimization design is performed on the lightweight design space of the leg structure to obtain a first design model; Shelling the first design model, retaining the target wall thickness, with the interior being a hollow cavity, to generate a second design model of a closed leg structure; Adding a reinforcing rib plate parallel to the vertical direction inside the cavity of the second design model, and adding a face lattice on the inner wall of the cavity to obtain a third design model; The third design model is subjected to dynamic and static simulation analysis using finite element analysis software to obtain simulation results; the wall thickness of different areas of the calf structure and the non-uniform weight-reducing structural distribution of the middle reinforcing rib plate are optimized using the simulation results as input, and the non-uniform surface lattice structure of the inner wall surface of the hollow cavity is optimized using a variable density method to obtain a target design model; Slicing and process planning the target design model by computer software to obtain a target printing model; Selective laser melting technology is used, and lightweight metal powder materials with optimized composition are used as raw materials for parts processing. The file corresponding to the target printing model is imported into the additive equipment to complete the integrated manufacturing of parts.

2. The method for lightweight design and manufacturing of quadruped robot legs according to claim 1, characterized in that: The non-uniform weight reduction structure includes non-uniform weight reduction holes.

3. The method for lightweight design and manufacturing of quadruped robot legs according to claim 1, characterized in that: According to the requirements of the quadruped robot leg structure on the comprehensive mechanical properties of the material, the composition of the existing lightweight metal powder material is adjusted, and the comprehensive mechanical properties of the material are improved by adding strengthening elements to obtain the lightweight metal powder material with optimized composition.

4. The method for lightweight design and manufacturing of quadruped robot legs according to claim 3, characterized in that: The existing lightweight metal powder material includes any one of aluminum alloy and titanium alloy.

5. A lightweight leg structure, characterized in that: It comprises a closed leg structure body manufactured by adopting the lightweight design and manufacturing method for the legs of a quadruped robot as described in any one of claims 1 to 4, wherein the interior of the closed leg structure body has a hollow cavity structure, a lightweight reinforcing rib plate with a non-uniform weight reduction structure is arranged in the hollow cavity structure, and the surface of the hollow cavity structure includes a non-uniform surface lattice reinforcement structure.

6. A quadruped robot, characterized in that: Comprising the lightweight leg structure as claimed in claim 5.

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