Bionic multi-degree-of-freedom ankle joint exoskeleton

Abstract

The invention relates to a highly-bionic multi-degree-of-freedom ankle joint exoskeleton. The exoskeleton comprises a binding part, a medial malleolus upper bionic structure, a medial malleolus lower bionic structure, a lateral malleolus upper bionic structure, a lateral malleolus lower bionic structure, an elastic connecting piece and a shoe cover. The binding part is used for binding on a shank; the binding part is connected with the medial malleolus upper bionic structure and the lateral malleolus upper bionic structure; the shoe cover is connected with the medial malleolus lower bionic structure and the lateral malleolus lower bionic structure; the upper malleolus medialis bionic structure and the lower malleolus medialis bionic structure are connected through an elastic connecting piece and located on the inner side of the ankle joint. The lateral malleolus upper bionic structure and the lateral malleolus lower bionic structure are connected through an elastic connecting piece and located on the outer side of the ankle joint. The medial malleolus upper bionic structure and the medial malleolus lower bionic structure simulate the contact surface of the medial malleolus and the talus of the ankle joint through an S-shaped curved surface structure; the lateral malleolus upper bionic structure and the lateral malleolus lower bionic structure simulate the contact surface of the lateral malleolus and the talus through the ellipsoidal curved surface structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of passive exoskeleton, and particularly relates to a highly bionic multi-degree-of-freedom ankle exoskeleton product. BACKGROUND

[0002] In recent years, passive lower limb exoskeleton technology has developed rapidly. Due to its advantages such as light weight, high efficiency and stability, it can significantly reduce the energy consumption of human high-load movement, and is widely used in the fields of fire fighting and special operations.

[0003] At present, the design of passive lower limb exoskeleton ankle joints tends to be mature, and the structures tend to be convergent. Most of them decompose the degrees of freedom of ankle joints, which leads to a long distance between the three axes of the ankle exoskeleton and a mismatch with the human ankle joint, causing the movement of the human body and the exoskeleton to be out of sync. Secondly, the structural design of most ankle exoskeletons is complex, which leads to a large and cumbersome body, which is not conducive to the demand of reducing the burden of the human body.

[0004] The patent "Passive three-degree-of-freedom ankle exoskeleton" (202222816804.1, authorized, published on April 18, 2023) discloses a passive three-degree-of-freedom ankle exoskeleton. This three-degree-of-freedom ankle exoskeleton does not set up a driven drive, but realizes passive drive through the elastic element, i.e. spring, on the exoskeleton. The elastic element can store and release energy during walking. Compared with the exoskeleton structure driven by an external power source, it is simpler, more reliable, flexible, and has lower cost. The disadvantage is that the three-degree-of-freedom structure is designed separately, and the distance between each structure is large, which leads to a complex overall structure, a large mass, and a large space range required for movement.

[0005] The patent "Bionic three-degree-of-freedom exoskeleton ankle joint" (201810007994.8, authorized, published on February 18, 2020) discloses a bionic three-degree-of-freedom exoskeleton ankle joint. This bionic three-degree-of-freedom exoskeleton ankle joint ensures that the intersection of the three-degree-of-freedom rotation center lines coincides with the center of the human ankle joint through structural layout design, making the wearer's movement more natural and avoiding the movement interference between the exoskeleton and the human body in space. The disadvantage is that the entire structure adopts a parallelogram structure, which has many parts, large size and weight, and increases the burden of the joint. SUMMARY

[0006] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a bionic ankle joint structure with light weight, high flexibility and high human-machine matching.

[0007] The technical solution of the present application is: a bionic multi-degree-of-freedom ankle exoskeleton, which comprises a binding, an upper bionic structure of the medial malleolus, a lower bionic structure of the medial malleolus, an upper bionic structure of the lateral malleolus, a lower bionic structure of the lateral malleolus, an elastic connecting piece and a shoe cover.

[0008] The binding is used for binding on the lower leg; the binding is connected with the upper bionic structure of the medial malleolus and the upper bionic structure of the lateral malleolus; the shoe cover is connected with the lower bionic structure of the medial malleolus and the lower bionic structure of the lateral malleolus;

[0009] The upper bionic structure of the medial malleolus is connected with the lower bionic structure of the medial malleolus through an elastic connecting piece and is located on the medial side of the ankle joint;

[0010] The upper bionic structure of the lateral malleolus is connected with the lower bionic structure of the lateral malleolus through an elastic connecting piece and is located on the lateral side of the ankle joint;

[0011] The upper bionic structure of the medial malleolus and the lower bionic structure of the medial malleolus are connected through an S-shaped curved surface structure to simulate the contact surface of the medial malleolus and the talus of the ankle joint;

[0012] The upper bionic structure of the lateral malleolus and the lower bionic structure of the lateral malleolus are connected through an ellipsoidal curved surface structure to simulate the contact surface of the lateral malleolus and the talus.

[0013] Preferably, the binding is a ring structure, which is sequentially connected by an elastic part I, a fixed connecting part I, an elastic part II and a fixed connecting part II;

[0014] The elastic part I and the elastic part II are located on the left and right sides of the lower leg, and the fixed connecting part I and the fixed connecting part II are located on the front and back sides of the lower leg.

[0015] Preferably, the elastic part I and the elastic part II are made of elastic nylon material; and the fixed connecting part I and the fixed connecting part II are made of composite material.

[0016] Preferably, the upper bionic structure of the medial malleolus, the lower bionic structure of the medial malleolus, the upper bionic structure of the lateral malleolus and the lower bionic structure of the lateral malleolus are manufactured by D printing technology.

[0017] Preferably, the upper bionic structure of the medial malleolus, the lower bionic structure of the medial malleolus, the upper bionic structure of the lateral malleolus and the lower bionic structure of the lateral malleolus are made of polylactic acid.

[0018] Preferably, the elastic connecting piece is made of stainless steel soft spring, and external thread connectors are arranged at two ends of the elastic connecting piece, so that the elastic connecting piece is convenient to connect.

[0019] Preferably, the curved surface of the upper bionic structure of the medial malleolus simulates the curved surface of the medial malleolus of the ankle joint of the human body, and the curved surface of the lower bionic structure of the medial malleolus simulates the curved surface of the talus of the ankle joint of the human body, so that the upper bionic structure of the medial malleolus can rotate forward and backward and rotate left and right around the lower bionic structure of the medial malleolus, and simulate the dorsiflexion or plantarflexion trajectory and the varus or valgus trajectory.

[0020] Preferably, the curved surface of the upper bionic structure of the lateral malleolus simulates the curved surface of the lateral malleolus of the ankle joint of the human body, and the curved surface of the lower bionic structure of the lateral malleolus simulates the curved surface of the talus of the ankle joint of the human body.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] This invention proposes S-shaped and ellipsoidal surface biomimetic structures. The S-shaped surface structure imitates the contact surface between the medial malleolus and the talus of the ankle joint, while the ellipsoidal surface structure imitates the contact surface between the lateral malleolus and the talus. These two biomimetic structures are connected by four elastic elements, enabling flexible multi-degree-of-freedom movements of the ankle exoskeleton, including plantar flexion / dorsiflexion, inversion / eversion, and adduction / abduction. At the same time, the compression and stretching of the elastic connectors provide energy storage assistance for ankle joint movement, solving the problems of complex ankle exoskeleton configurations and low fit with the human body. Attached Figure Description

[0023] Figure 1 This is a front view of the biomimetic multi-degree-of-freedom ankle exoskeleton structure according to an embodiment of the present invention.

[0024] Figure 2 This is a rear view of the biomimetic multi-degree-of-freedom ankle exoskeleton structure according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the biomimetic multi-degree-of-freedom ankle exoskeleton binding structure according to an embodiment of the present invention.

[0026] Figure 4(a) is a schematic diagram of the curved surface of the superior medial malleolus bionic structure and the inferior medial malleolus bionic structure in an example of the present invention.

[0027] Figure 4(b) is a schematic diagram of the lateral view of the curved surfaces of the biomimetic structures above and below the medial malleolus in an example of the present invention.

[0028] Figure 5(a) is a schematic diagram of the curved surface of the upper and lower lateral malleolus bionic structures in an example of the present invention.

[0029] Figure 5(b) is a schematic diagram of the outer side view of the curved surface of the biomimetic structure above and below the lateral malleolus in an example of the present invention.

[0030] Figure 6 This is a schematic diagram of the elastic connector structure of an example of the present invention.

[0031] Figure 7 This is a schematic diagram of the foot cover structure in an example of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the embodiments.

[0033] like Figure 1 , 2 As shown, the present invention provides a highly biomimetic multi-degree-of-freedom ankle exoskeleton structure, including a binding 1, a biomimetic structure on the medial malleolus 2, elastic connectors 3, 4, 5, 6, 9, 10, 11, 12, a biomimetic structure on the medial malleolus 7, a biomimetic structure on the lateral malleolus 8, a biomimetic structure on the lateral malleolus 13, and a shoe cover 14.

[0034] As Figure 3 shown, the binding 1 mainly includes elastic part I 15, elastic part II 16, fixed connection part I 17, fixed connection part II 18, elastic part I and elastic part II are selected from elastic nylon material, which has elastic amount to facilitate wearing and disassembling; the fixed connection part I and the fixed connection part II are selected from composite materials such as polyurethane and polylactic acid, and threaded holes 19, 20, 21, 22 are provided on the fixed connection part I and the fixed connection part II; the elastic part and the fixed connection part are fixedly connected through an adhesive.

[0035] As shown in FIG. 4 and FIG. 5, the bionic curved surface structure can be parameterized designed according to the ankle joint structure data of human body, manufactured by 3D printing technology, and the material is polylactic acid, which has high strength and light weight, and can realize high matching between man and machine;

[0036] Threaded holes 23, 24, 25, 26, 27, 28 are punched on the upper bionic structure of the medial malleolus, threaded holes 33, 34, 29, 30, 31, 32 are punched on the lower bionic structure of the medial malleolus, threaded holes 35, 36, 37, 38, 39, 40 are punched on the upper bionic structure of the lateral malleolus, and threaded holes 41, 42, 43, 44, 45, 46 are punched on the lower bionic structure of the lateral malleolus;

[0037] The upper bionic structure of the medial malleolus, the upper bionic structure of the lateral malleolus and the binding structure are fixedly connected through screws, and the matching relationship of the threaded holes is that threaded hole 19 and threaded hole 24 match, threaded hole 20 and threaded hole 23 match, threaded hole 21 and threaded hole 35 match, and threaded hole 22 and threaded hole 36 match. The upper bionic structure of the medial malleolus and the lower bionic structure of the medial malleolus are connected through four elastic connecting pieces, and the upper bionic structure of the lateral malleolus and the lower bionic structure of the lateral malleolus are connected through four elastic connecting pieces, as Figure 6 shown, in order to simulate the characteristics of human ankle ligament, the elastic connecting piece is selected from stainless steel soft spring 48, which satisfies the functions of stretching, compression and torsion, and the two ends 47 and 49 of the elastic connecting piece have external thread connection heads. The connection relationship between the bionic structure and the elastic connection is that the elastic connecting piece 3 matches with threaded hole 25 and threaded hole 29, the elastic connecting piece 4 matches with threaded hole 28 and threaded hole 31, the elastic connecting piece 5 matches with threaded hole 26 and threaded hole 30, and the elastic connecting piece 6 matches with threaded hole 28 and threaded hole 32.

[0038] As Figure 7 shown, the sole 51 of the foot cover is made of rubber material, and the upper 50 is woven from polyester fiber material, which can be designed individually according to the foot size of the wearer, and the sole is provided with through holes 52, 53, 54, 55, and the sole is connected with the lower bionic structure of the medial malleolus and the lower bionic structure of the lateral malleolus through screws, and the connection relationship is that through hole 52 and threaded hole 34 match, through hole 53 and threaded hole 33 match, through hole 54 and threaded hole 45 match, and through hole 55 and threaded hole 46 match.

[0039] As shown in FIG. 4(a) and FIG. 4(b), the contact surface between the upper medial malleolus bionic structure 2 and the lower medial malleolus bionic structure 7 is designed as an S-shaped bionic curved surface. The curved surface of the upper medial malleolus bionic structure 2 imitates the curved surface of the medial malleolus of the human ankle joint, and the curved surface of the lower medial malleolus bionic structure 7 imitates the curved surface of the talus of the human ankle joint. The upper medial malleolus bionic structure 2 can rotate around the lower medial malleolus bionic structure 7 in front and back and left and right, simulating the dorsiflexion or plantarflexion trajectory and the varus or valgus trajectory. The front and back rotation of the upper medial malleolus bionic structure 2 and the end surface motion trajectory 57 of the lower medial malleolus bionic structure 7 is an arc, and the left and right rotation of the upper medial malleolus bionic structure 2 and the end surface motion trajectory 57 of the lower medial malleolus bionic structure 7 is an S curve. The elastic connecting pieces 3, 4, 5, and 6 distributed in front, back, left, and right can ensure the flexible movement of the upper medial malleolus bionic structure 2. When dorsiflexion, the elastic connecting piece 4 is compressed and the elastic connecting piece 6 is stretched. When plantarflexion, the elastic connecting piece 6 is compressed and the elastic connecting piece 4 is stretched. When adduction and abduction, due to the flexibility of the elastic connecting pieces 3, 4, 5, and 6 and the curvature of the contact surface of the left and right bionic structures, the ankle joint can rotate freely. When varus, the elastic connecting piece 3 is compressed and the elastic connecting piece 5 is stretched. When valgus, the elastic connecting piece 5 is compressed and the elastic connecting piece 3 is stretched. The compression of the elastic connecting piece provides energy storage during the heel landing stage, and the elastic connecting piece 3 and the elastic connecting piece 5 recover deformation during the toe-off stage, releasing energy to push the ankle joint to valgus. At the same time, the compression and stretching of the elastic connecting piece and the S-shaped bionic curved surface can limit the rotation angle of the upper medial malleolus bionic structure 2.

[0040] As shown in FIG. 5(a) and FIG. 5(b), the contact surface between the upper lateral malleolus bionic structure 8 and the lower lateral malleolus bionic structure 13 is designed as an elliptical spherical surface. The curved surface of the upper lateral malleolus bionic structure 8 imitates the curved surface of the lateral malleolus of the human ankle joint, and the curved surface of the lower lateral malleolus bionic structure 7 imitates the curved surface of the talus of the human ankle joint. The upper lateral malleolus bionic structure 8 can rotate around the lower lateral malleolus bionic structure 13 in front and back 58 and left and right 59, simulating the dorsiflexion or plantarflexion trajectory and the varus or valgus trajectory.

[0041] The end surface motion track 57 of the front and rear rotation upper outer malleolus bionic structure 8 and the lower outer malleolus bionic structure 13 is an elliptic arc line, and the end surface motion track 57 of the left and right rotation upper outer malleolus bionic structure 8 and the lower outer malleolus bionic structure 13 is an elliptic arc line. The elastic connecting pieces 9, 10, 11 and 12 distributed in front, back, left and right can ensure the flexible movement of the upper outer malleolus bionic structure 8, the elastic connecting piece 9 is compressed and the elastic connecting piece 11 is stretched in dorsiflexion, the elastic connecting piece 11 is compressed and the elastic connecting piece 9 is stretched in plantar flexion, the elastic connecting piece 10 is compressed and the elastic connecting piece 12 is stretched in inversion, the elastic connecting piece 12 is compressed and the elastic connecting piece 10 is stretched in eversion, the compression of the elastic connecting piece provides energy storage in the heel landing stage, and the elastic connecting piece releases energy to assist in pushing off in the toe-off stage, and the compression and stretching of the elastic connecting piece and the elliptic spherical surface structure can limit the rotation angle of the upper outer malleolus bionic structure 8.

[0042] The inner malleolus and the outer malleolus bionic structure keep the same height of the curved surface contact, so that the movement relationship of the inner malleolus and the outer malleolus bionic structure is coupled, and the interference of movement is avoided.

[0043] Compared with the prior art, the present application has at least the following beneficial effects:

[0044] (1) The curved surface bionic structure of the ankle joint of the present application is highly consistent with the ankle joint model of the human body, and can realize personalized production and manufacturing, and keeps high consistency with the sectional structure of the human ankle joint, and improves the man-machine matching.

[0045] (2) The present application uses elastic elements as the connecting structure of the ankle joint, and selects stainless steel soft springs, which on the one hand simulates the structural characteristics of the ankle ligament, and on the other hand the compression and stretching of the elastic connecting piece can provide power assistance for the movement of the ankle joint to reduce the human body movement consumption.

[0046] (3) The present application uses eight elastic connecting pieces, which is different from the previous complex connecting rod structure, and the bionic structure uses polylactic acid composite material with low density, which reduces the complexity and weight of the structure.

[0047] Although the present application has been disclosed with reference to the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not deviate from the technical solutions of the present application, belongs to the protection scope of the technical solutions of the present application.

Claims

1. A biomimetic multi-degree-of-freedom ankle exoskeleton, characterized in that... Includes binding (1), medial malleolus upper bionic structure (2), medial malleolus lower bionic structure (7), lateral malleolus upper bionic structure (8), lateral malleolus lower bionic structure (13), elastic connectors (3, 4, 5, 6, 9, 10, 11, 12) and shoe cover (14); The binding (1) is used to bind the lower leg; the binding (1) is connected to the bionic structure (2) on the medial malleolus and the bionic structure (8) on the lateral malleolus; the shoe cover (14) is connected to the bionic structure (7) on the medial malleolus and the bionic structure (13) on the lateral malleolus; The superior medial malleolus bionic structure (2) and the inferior medial malleolus bionic structure (7) are connected by elastic connectors (3, 4, 5, 6) and are located on the medial side of the ankle joint; The upper lateral malleolus bionic structure (8) and the lower lateral malleolus bionic structure (13) are connected by elastic connectors (9, 10, 11, 12) and are located on the lateral side of the ankle joint; The superior medial malleolus bionic structure (2) and the inferior medial malleolus bionic structure (7) mimic the contact surface between the medial malleolus and the talus of the ankle joint through an S-shaped curved surface structure; The upper lateral malleolus biomimetic structure (8) and the lower lateral malleolus biomimetic structure (13) mimic the contact surface between the lateral malleolus and the talus through an ellipsoidal curved surface structure.

2. The highly biomimetic multi-degree-of-freedom ankle exoskeleton according to claim 1, characterized in that, The binding (1) is a ring structure, which is formed by connecting the elastic part I (15), the fixed connection part I (17), the elastic part II (16), and the fixed connection part II (18) end to end in sequence; Elastic part I (15) and elastic part II (16) are positioned opposite each other and located on the left and right sides of the lower leg. Fixed connection part I (17) and fixed connection part II (18) are positioned opposite each other and located on the front and back sides of the lower leg.

3. The highly biomimetic multi-degree-of-freedom ankle exoskeleton according to claim 1, characterized in that, The elastic part I and elastic part II are made of elastic nylon material; the fixed connection part I and fixed connection part II are made of composite material.

4. The highly biomimetic multi-degree-of-freedom ankle exoskeleton according to claim 1, characterized in that, The biomimetic structures (2), (7), (8), and (13) above and below the medial malleolus are manufactured using 3D printing technology.

5. The highly biomimetic multi-degree-of-freedom ankle exoskeleton according to claim 1, characterized in that, The biomimetic structures (2), (7), (8), and (13) above and below the medial malleolus are made of polylactic acid.

6. The biomimetic multi-degree-of-freedom ankle exoskeleton according to claim 1, characterized in that, The elastic connector is made of stainless steel soft spring, and has external threaded connectors at both ends for easy connection.

7. The highly biomimetic multi-degree-of-freedom ankle exoskeleton according to claim 1, characterized in that, The upper medial malleolus bionic structure (2) has a curved surface that mimics the medial malleolus surface of the human ankle joint, and the lower medial malleolus bionic structure (7) has a curved surface that mimics the talus surface of the human ankle joint, so that the upper medial malleolus bionic structure (2) can rotate forward and backward (57) and left and right (56) around the lower medial malleolus bionic structure (7), simulating dorsiflexion or plantarflexion trajectory and inversion or eversion trajectory.

8. The highly biomimetic multi-degree-of-freedom ankle exoskeleton according to claim 1, characterized in that, The upper lateral malleolus bionic structure (8) surface imitates the lateral malleolus surface of the human ankle joint, and the lower lateral malleolus bionic structure (7) surface imitates the talus surface of the human ankle joint.

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