A space crawling robot driven by artificial muscles

Abstract

The present invention discloses a space crawling robot driven by artificial muscles, comprising: a main body and four groups of leg and foot structures symmetrically distributed around the main body; the leg and foot structures comprise a thigh structure, a shank structure and a foot structure connected in sequence by the main body, the thigh structure comprises a hip joint assembly, and the hip joint assembly is arranged inside the main body and the thigh structure; the thigh structure is connected to the shank structure by a rotating shaft, and the shaft joint serves as the knee joint of the crawling robot; the foot structure comprises an ankle joint assembly; the hip joint assembly, the knee joint and the ankle joint assembly are driven by artificial muscles arranged in pairs, and the artificial muscles use carbon nanotube fibers as electrodes. The crawling robot of the present invention can crawl using the surface structure and material of a spacecraft, has high surface adaptability, and has a wide range of reach.

Description

Technical Field

[0001] The invention relates to the field of robots, and in particular to a space crawling robot driven by artificial muscles. Background Art

[0002] The wide adaptation of the super-large spacecraft's extravehicular structure to multiple obstacles and multiple types of surfaces without gripping points requires the robot to have high binding force on the crawling surface, while the long-term and fast crawling ability on multiple types of rough surfaces requires the robot to have high power density and low energy consumption driving ability. At present, there is little research on the high binding force and high power density of space bionic crawling robots at home and abroad, and the existing technical problems are mainly concentrated in the two aspects of weak adaptability to different target surfaces and low driving power density. Summary of the invention

[0003] The purpose of the present invention is to provide a robot that can realize fast and stable crawling motion functions in multi-type and multi-obstacle surface working environments in space microgravity environments and under high power density driving.

[0004] In order to achieve the above object, the present invention provides an artificial muscle-driven space crawling robot, comprising:

[0005] A main body and four groups of leg and foot structures symmetrically distributed around the main body;

[0006] The leg and foot structure includes a thigh structure, a calf structure and a foot structure which are sequentially connected by the main body, the thigh structure includes a hip joint assembly, and the hip joint assembly is arranged within the main body and the thigh structure; the thigh structure is axially connected to the calf structure, and the axial connection serves as the knee joint of the crawling robot; the foot structure includes an ankle joint assembly; the hip joint assembly, the knee joint and the ankle joint assembly are driven by artificial muscles arranged in pairs, and the artificial muscles use carbon nanotube fibers as electrodes.

[0007] Optionally, the hip joint component comprises:

[0008] A fixing plate connected to the body;

[0009] A first reversing gear, wherein the first reversing gear is a bevel gear;

[0010] a first artificial muscle, one end of which is connected to the fixing plate, and the other end of which is connected to the first reversing gear;

[0011] A second reversing gear, which is a bevel gear and is connected to the first reversing gear;

[0012] A universal joint, a base of which is fixedly connected to the output shaft of the second reversing gear;

[0013] The first artificial muscle drives the first reversing gear and the second reversing gear in sequence to make the universal joint rotate and roll.

[0014] Optionally, a second artificial muscle is connected to the universal joint to drive the pitch and yaw of the universal joint.

[0015] Optionally, a third artificial muscle is connected to the calf structure to drive the opening and closing of the calf structure and the thigh structure.

[0016] Optionally, the ankle joint assembly comprises:

[0017] A desorption motor connected to a desorption foot;

[0018] A cross rotating frame, arranged around the desorption motor, and connected to the desorption motor via a first rotating shaft;

[0019] An ankle supra-plate connected to the cross-rotating frame via a second rotating shaft;

[0020] One end of the fourth artificial muscle is connected to the calf structure, and the other end is connected to the cross-rotation frame. The pitch and yaw of the ankle joint assembly are driven by the fourth artificial muscle.

[0021] Optionally, the ankle joint assembly further comprises:

[0022] A first return spring, disposed on the same side of the second rotating shaft, one end of which is connected to the cross rotating frame, and the other end of which is connected to the desorption motor;

[0023] A second return spring is disposed on the same side of the first rotating shaft, one end of which is connected to the calf structure, and the other end of which is connected to the cross rotating frame;

[0024] The first return spring and the second return spring provide a preload force and a return force for the ankle joint assembly.

[0025] Optionally, after the adhesive-debonding foot is adhered to the target surface, the adhesive-debonding foot is peeled off the target surface by the debonding motor.

[0026] Optionally, a three-dimensional porous nanofiber membrane is deposited on the surface of the carbon nanotube fiber of the artificial muscle and encapsulated with a SEBS polymer.

[0027] Optionally, the artificial muscle is connected in series with a damper, and the damper antagonizes driving the artificial muscle.

[0028] Optionally, it also includes:

[0029] A perception module, a control module and a power supply module, wherein the perception module provides interaction information between the crawling robot and the external environment for crawling action, the control module converts the interaction information into the actuation amount of the artificial muscle and distributes it to the hip joint, knee joint and ankle joint to realize the crawling action of the robot, and the power supply module provides electrical energy for the robot.

[0030] The beneficial effects of the present invention are:

[0031] (1) Aiming at the high-efficiency driving function of reaching a large range in the multi-obstacle environment outside the cabin of a large spacecraft, the crawling robot of the present invention adopts CNTs artificial muscle drive, and draws on the characteristics of biological leg and foot structure and muscle antagonistic direct drive, combined with the multi-type and multi-obstacle surface working environment and the requirements of fast and stable crawling motion in the space microgravity environment, and proposes an overall structural scheme of antagonistic direct drive crawling robot coupled by artificial muscle and damper, which solves the problem of complex and bloated transmission mechanism in the past and realizes the compactness and lightness of crawling robot. At the same time, the artificial muscle adopts a full solid-state bionic muscle driver based on non-gel electrolyte, which has high power density and large strain driving capability under the condition of meeting the space environment.

[0032] (2) The crawling robot of the present invention has the ability to crawl efficiently on space-type surfaces. The adhesive material at the foot of the crawling robot generates microscopic adhesion with the target surface, produces strong interface strength, and the adhesion process is reversible and has a long service life, and can adapt to different types of surface structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of the space crawling robot of the present invention.

[0034] Figure 2 Schematic diagram of the CNTs artificial muscle structure and driving mechanism of the present invention.

[0035] Figure 3 This is a schematic structural diagram of the hip joint assembly of the space crawling robot of the present invention.

[0036] Figure 4 It is a schematic diagram of the universal joint structure of the space crawling robot of the present invention.

[0037] Figure 5 This is a schematic diagram of the knee joint structure of the space crawling robot of the present invention.

[0038] Figure 6 This is a schematic diagram of the foot structure of the space crawling robot of the present invention.

[0039] In the figure, 1-main body, 2-leg and foot structure, 21-thigh structure, 210-hip joint assembly, 211-fixed plate, 212-first artificial muscle, 213-first reversing gear, 214-second reversing gear, 215-universal joint, 216-second artificial muscle, 22-calf structure, 220-knee joint, 221-third artificial muscle, 23-foot structure, 230-ankle joint assembly, 231-detachment motor, 232-adhesion and detachment foot, 233-cross rotating frame, 234-first rotating shaft, 235-ankle plate, 236-second rotating shaft, 237-fourth artificial muscle, 238-first return spring, 239-second return spring, 3-target surface. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] like Figure 1As shown, the overall design of the robot of the present invention draws on the biological leg and foot structure form and the muscle antagonism direct drive characteristics, including a body 1 and four groups of leg and foot structures 2 symmetrically distributed around the body. The whole machine adopts a central symmetrical layout, and each group of leg and foot structures is the same. In the figure, the body 1 is a regular octagon, and the four groups of leg and foot structures are symmetrically distributed on four sides of the octagon. The initial state of the robot is at an angle of π / 4+kπ / 2 (k=0,1,2,3) with the forward direction. The leg and foot structure 2 includes a thigh structure 21, a shank structure 22 and a foot structure 23 connected in sequence by the body 1. The thigh structure 21 includes a hip joint assembly, and the hip joint assembly is arranged inside the body 1 and the thigh structure 21; the thigh structure 21 is connected to the shank structure 22 with a swivel, and the swivel joint is used as the knee joint of the crawling robot; the foot structure 23 includes an ankle joint assembly; the hip joint assembly, the knee joint and the ankle joint assembly are driven by artificial muscles arranged in pairs.

[0044] In order to achieve surface-adaptive high-binding force crawling, it is necessary to increase the unit driving force of the robot movement to ensure that the foot end contact pressure meets the high adhesion effect. At present, all space crawling robots are driven by motors. Motor drive has the advantages of high energy conversion efficiency and large driving force, but due to the large size of the transmission mechanism, the robot usually has large joints and is bulky as a whole, resulting in low power density. Artificial muscle drive has the advantages of high power density, large drive strain, no intermediate transmission, small size, etc. Carbon nanotube fiber (CNTs) all-solid-state artificial muscle, as a representative of electrochemically driven artificial muscles, is the best way to meet the high power density drive of bionic adhesion crawling robots in space environments.

[0045] like Figure 2As shown in the figure, the artificial muscle uses multi-level micro / nanostructured carbon nanotube fibers (CNTs) as electrodes, and a uniform three-dimensional porous nanofiber membrane is deposited on the surface of the carbon nanotube fibers to avoid the short circuit caused by the contact of the two electrodes. Finally, the artificial muscle fibers are encapsulated with a high elasticity and low modulus SEBS (styrene-ethylene-butylene-styrene block copolymer) polymer. The structure of the multi-level high-twist through-the-wire carbon nanotube fibers is regulated by controlling the helical twist, original fiber length, and number of helical turns of CNTs during preparation. The adaptability of the artificial muscle to the space environment is met by adjusting the size of anions and cations and the lattice energy in the solid ionic liquid. By self-twisting the positive and negative electrodes of the bionic muscle fibers, the bionic muscle fibers are stabilized without being bound at both ends, and then multiple all-solid-state bionic muscle fibers are woven into fiber bundles to achieve mutual cooperation between the fiber filaments and jointly complete the actuation and load transfer of the bundled fibers. The artificial muscle and the damper are connected in series to form an actuator module, which adopts the coupling antagonistic drive form of CNTs artificial muscle and damper. The actuators are arranged symmetrically, and the dampers provide a certain preload and restoring force to make one set of artificial muscles contract and the other set of artificial muscles relax, thereby realizing the corresponding joint rotation. The space crawling robot based on carbon nanotube (CNTs) artificial muscle drive and dry adhesion mechanism can meet the requirements of long-endurance and efficient crawling capabilities for large-scale spacecraft on-orbit service and maintenance missions in space with multiple obstacles and a large range of reach.

[0046] Through CNTs artificial muscles, a single set of leg and foot structures of the crawling robot of the present invention has 6 degrees of freedom, including 3 degrees of freedom of the hip joint assembly, 1 degree of freedom of the knee joint and 2 degrees of freedom of the ankle joint assembly. The robot has 4 sets of leg and foot structures, so the degree of freedom of the entire robot is 24. The following specifically introduces the movement modes of the hip joint assembly, knee joint and ankle joint assembly.

[0047] The hip joint assembly has three degrees of freedom, including roll, pitch, and yaw. Figure 3 As shown, the hip joint assembly includes a fixing plate 211 connected to the main body 1, one end of the first artificial muscle 212 is connected to the fixing plate 211, and the other end is connected to the first reversing gear 213. The first artificial muscle 212 includes a pair of antagonistically distributed CNTs artificial muscles. The first reversing gear 213 is connected to the second reversing gear 214, and the first reversing gear 213 and the second reversing gear 214 are bevel gears. The base of the universal joint 215 is fixedly connected to the output shaft of the second reversing gear 214. The first pair of artificial muscles 212 sequentially drives the first reversing gear 213 and the second reversing gear 214 to rotate the universal joint 215 to achieve the roll of the universal joint 215. The universal joint 215 itself can achieve pitch and yaw. Specifically, as Figure 4As shown, a second artificial muscle 216 is connected to the universal joint 215, and the second artificial muscle 216 includes two pairs of antagonistically distributed CNTs artificial muscles. The pitch and yaw of the universal joint 215 are driven by the stretching and contraction of the second artificial muscle 216.

[0048] The knee joint has 1 degree of freedom. Figure 5 As shown, the third artificial muscle 221 includes two pairs of antagonistically distributed CNTs artificial muscles. The third artificial muscle 221 is entirely arranged in the thigh structure 21, one end of which is connected to the calf structure 22, and the other end is connected to the thigh structure 21 to drive the opening and closing between the calf structure 22 and the thigh structure 21.

[0049] Arriving in a large-scale environment with multiple obstacles outside the cabin faces the problem of no surface structure available for grasping. Therefore, the gripping method based on the clamp type cannot adapt to the continuous smooth surface. Bionic attachment and electromagnetic adsorption are two optional attachment and crawling methods. The normal adhesion strength of the high-binding force stable crawling on the flexible component is relatively high, because the adhesion of the electrostatic adsorption method is relatively low, and dry adhesion has the advantages of strong surface adaptability, high interface strength, reversible process and long service life, and does not require any chemical medium environment and external field. It is the best way to attach and crawl in space vacuum, high and low temperature environment. The adhesive and detachable foot of the present invention is composed of an adhesive foot pad imitating the structure of the gecko bristle and a centrally symmetrical detachable claw imitating the structure of the front tarsal segment of an insect. The micrometer-scale array structure on the surface of the adhesive foot pad generates a microscopic adhesion force with the target surface, thereby providing a reversible process for the crawling robot and an attachment method that does not require any chemical medium and satisfies the space vacuum, high and low temperature environment. The detachable claw drives the connecting rod mechanism to peel off the adhesive foot pad from the adsorption surface through the rapid actuation of the central piezoelectric driver, thereby achieving rapid and efficient detachment.

[0050] The ankle joint component has 2 degrees of freedom. Figure 6As shown, the ankle joint assembly is a universal joint configuration. The ankle joint assembly includes a desorption motor 231, and the desorption motor 231 is connected to the adhesive-desorption foot 232. When the foot end of the crawling robot contacts the target surface, the foot pad of the adhesive-desorption foot 232 generates a microscopic adhesive force with the target surface 3, thereby realizing the combination of the crawling robot and the target surface. When the foot end of the crawling robot contacts the target surface, the desorption claw of the adhesive-desorption foot 232 is quickly actuated by the piezoelectric driver of the desorption motor 231 to drive the connecting rod mechanism to peel the foot pad off the target surface, thereby realizing fast and efficient desorption. ; A cross-rotating frame 233 is arranged around the desorption motor 231 and is connected to the desorption motor 231 through a first rotating shaft 234; an ankle plate 235 is connected to the cross-rotating frame 233 through a second rotating shaft 236; a fourth artificial muscle 237 comprises two pairs (four groups) of antagonistically distributed CNTs artificial muscles, one end of which is connected to the calf structure 22 and the other end of which is connected to the cross-rotating frame 233, and the pitch and yaw of the ankle joint assembly are driven by the fourth artificial muscle 237. Specifically, the two groups of artificial muscles on one side of the first rotating shaft 234 stretch or contract, and the two groups of artificial muscles on the other side of the first rotating shaft 234 contract or stretch, so that the detachment motor 211 and the cross rotating frame 233 rotate relative to each other by β, thereby realizing the pitch of the ankle joint assembly; the two groups of artificial muscles on one side of the second rotating shaft 236 stretch or contract, and the two groups of artificial muscles on the other side of the second rotating shaft 236 contract or stretch, so that the cross rotating frame 233 and the ankle upper plate 235 rotate relative to each other by α, thereby realizing the yaw of the ankle joint assembly. Through the pitch and yaw of the ankle joint assembly, the angle θ formed between the adhesive-detachable foot 232 and the target surface 3 is regulated, so that the adhesive-detachable foot 232 is adsorbed or detached from the target surface 3.

[0051] Furthermore, the ankle joint assembly also includes: a first return spring 238, which is arranged on the same side of the second rotating shaft 236, one end of which is connected to the cross rotating frame 233, and the other end is connected to the detachment motor 231; a second return spring 239, which is arranged on the same side of the first rotating shaft 234, one end of which is connected to the calf structure 22, and the other end is connected to the cross rotating frame 233; the passive return unit composed of the first return spring 238 and the second return spring 239, through the structural optimization of the symmetrically distributed return springs, on the one hand, provides a certain preload and return force for the ankle joint, and on the other hand, can adapt to a target surface of a certain angle. When the fourth artificial muscle 237 fails, the fourth artificial muscle 237 can be regarded as a spring, and it rotates passively under the action of external force together with the first return spring 238 and the second return spring 239.

[0052] The robot of the present invention also includes a perception module, a control module and a power supply module. The perception module provides interaction information between the crawling robot and the external environment for the crawling action. The control module converts the interaction information into the actuation amount of the artificial muscle and distributes it to the hip joint, knee joint and ankle joint to realize the crawling action of the robot. The power supply module provides electrical energy for the robot.

[0053] In summary, the present invention provides a crawling robot adapted to the space environment, which drives the robot to move through antagonistically distributed CNTs artificial muscles. The design is modeled after the structure of biological legs and feet. The hip joint assembly includes a pair of reversing gears and a universal joint. The universal joint base is fixedly connected to the reversing gear output shaft, which can realize the rolling of the universal joint base, and the universal joint itself can realize pitch and yaw; the ankle joint assembly includes CNTs artificial muscles that can be actively adjusted and spring units that can passively return. The ankle joint assembly adopts a universal joint configuration, which can realize two-degree-of-freedom rotational movement of the foot end. The crawling robot of the present invention can crawl using the surface structure and material of the spacecraft, has high surface adaptability, and has a wide range of reach.

[0054] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. An artificial muscle-driven space crawling robot, characterized in that: include: A main body and four groups of leg and foot structures symmetrically distributed around the main body; The leg and foot structure comprises a thigh structure, a shank structure and a foot structure which are sequentially connected by the body, the thigh structure comprises a hip joint assembly, and the hip joint assembly is arranged inside the body and the thigh structure; the thigh structure is connected to the shank structure with a swivel, and the swivel joint serves as the knee joint of the crawling robot; the foot structure comprises an ankle joint assembly; the hip joint assembly, the knee joint and the ankle joint assembly are driven by artificial muscles arranged in pairs, and the artificial muscles use carbon nanotube fibers as electrodes; The hip joint assembly comprises: A fixing plate connected to the body; A first reversing gear, wherein the first reversing gear is a bevel gear; a first artificial muscle, one end of which is connected to the fixing plate, and the other end of which is connected to the first reversing gear; A second reversing gear, which is a bevel gear and is connected to the first reversing gear; A universal joint, a base of which is fixedly connected to the output shaft of the second reversing gear; The first artificial muscle drives the first reversing gear and the second reversing gear in sequence to make the universal joint rotate and roll; The ankle joint assembly comprises: A desorption motor connected to a desorption foot; A cross rotating frame, arranged around the desorption motor, and connected to the desorption motor via a first rotating shaft; An ankle supraspinatus plate connected to the cross-rotating frame via a second rotating shaft; One end of the fourth artificial muscle is connected to the calf structure, and the other end is connected to the cross-rotation frame, so as to drive the pitch and yaw of the ankle joint assembly through the fourth artificial muscle; The artificial muscle is connected in series with a damper, and the damper antagonizes driving the artificial muscle.

2. The artificial muscle-driven space crawling robot according to claim 1, characterized in that: The universal joint is connected with a second artificial muscle to drive the pitch and yaw of the universal joint.

3. The artificial muscle-driven space crawling robot according to claim 1, characterized in that: The calf structure is connected with a third artificial muscle to drive the opening and closing of the calf structure and the thigh structure.

4. The artificial muscle-driven space crawling robot according to claim 1, characterized in that: The ankle joint assembly further comprises: A first return spring, arranged on the same side of the second rotating shaft, one end of which is connected to the cross rotating frame, and the other end of which is connected to the desorption motor; A second return spring is disposed on the same side of the first rotating shaft, one end of which is connected to the calf structure, and the other end of which is connected to the cross rotating frame; The first return spring and the second return spring provide a preload force and a return force for the ankle joint assembly.

5. The artificial muscle-driven space crawling robot according to claim 1, characterized in that: After the adhesive-debonding foot is adhered to the target surface, the adhesive-debonding foot is peeled off the target surface by the debonding motor.

6. The artificial muscle-driven space crawling robot according to claim 1, characterized in that: A three-dimensional porous nanofiber membrane is deposited on the surface of the carbon nanotube fiber of the artificial muscle and is encapsulated with a SEBS polymer.

7. The artificial muscle-driven space crawling robot according to claim 1, characterized in that: Also includes: A perception module, a control module and a power supply module, wherein the perception module provides interaction information between the crawling robot and the external environment for crawling action, the control module converts the interaction information into the actuation amount of the artificial muscle and distributes it to the hip joint, knee joint and ankle joint to realize the crawling action of the robot, and the power supply module provides electrical energy for the robot.

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