Micro six-legged crawling robot based on shape memory alloy driving

Abstract

The application discloses a micro six-legged crawling robot driven by shape memory alloy, which comprises a body, leg structures, internal guide wheels, internal shape memory alloy wires, external guide wheels and external shape memory alloy wires; six leg structures are symmetrically distributed on the left and right sides of the body, and the tibial shaft of the leg structure is rotationally connected with the body; three internal guide wheels are rotationally installed on the left and right sides of the inner wall of the body bottom plate, and three external guide wheels are rotationally installed on the left and right sides of the outer wall of the body bottom plate; each leg structure corresponds to an internal shape memory alloy wire and an external shape memory alloy wire; one end of the internal shape memory alloy wire is fixedly connected with one side of the body mounting the leg structure, and the other end is wound on the tibial shaft of the leg structure after passing through the corresponding internal guide wheel on the opposite side of the leg structure; one end of the external shape memory alloy wire is fixedly connected with one side of the body mounting the leg structure, and the other end is fixedly connected with the middle part of the leg segment of the leg structure after passing through the corresponding external guide wheel on the opposite side of the leg structure. By increasing the deformation of the shape memory alloy wire, the stride and leg releasing amplitude are increased, and the advancing speed is faster.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of micro robots, and particularly relates to a micro six-legged crawling robot driven by shape memory alloy. BACKGROUND

[0002] With the development of robot technology, micro bionic robots have attracted widespread attention. The size of the micro bionic robot is usually between several centimeters and tens of centimeters, and the micro bionic robot is particularly suitable for tasks such as earthquake disaster rescue, narrow pipeline exploration and data collection. Compared with a wheeled structure, a legged robot shows better adaptability in complex terrain.

[0003] A driver is a key factor affecting the performance of a micro bionic robot. Although an electric motor is widely used due to its controllability and high precision, the electric motor has disadvantages such as low degree of freedom, poor flexibility, large weight and high noise, which are not conducive to the miniaturization of the robot. Therefore, researchers have explored drivers made of materials such as shape memory alloy (SMA), ion polymer metal composite (IPMC), piezoelectric ceramic and dielectric elastomer. The SMA driver has advantages such as high power-to-weight ratio, compact size and silence, and is an ideal choice for the design of a micro robot. However, existing SMA-driven robots have problems such as slow marching speed, which limits their practical application.

[0004] Therefore, the application designs a micro six-legged crawling robot driven by shape memory alloy. By increasing the stroke of the shape memory alloy wire, the amplitude of leg lifting and leg lifting of the robot is increased, so that the marching speed of the robot is improved. SUMMARY

[0005] In view of the deficiencies of the prior art, the application aims to solve the technical problem of providing a micro six-legged crawling robot driven by shape memory alloy.

[0006] In order to solve the above technical problems, the application adopts the following technical scheme:

[0007] A micro six-legged crawling robot driven by shape memory alloy, characterized in that the robot comprises a body, a leg structure, an internal guide wheel, an internal shape memory alloy wire, an external guide wheel and an external shape memory alloy wire.

[0008] Six leg structures are symmetrically distributed on the left and right sides of the fuselage, and a tibial shaft of the leg structure is rotationally connected with the fuselage; three internal guide wheels are rotationally installed on the left and right sides of the inner wall of the fuselage bottom plate respectively, and three external guide wheels are rotationally installed on the left and right sides of the outer wall of the fuselage bottom plate respectively; the leg lifting action of each leg structure is driven by an internal shape memory alloy wire, one end of the internal shape memory alloy wire is fixedly connected with one side of the fuselage on which the leg structure is installed, the internal shape memory alloy wire passes through the corresponding internal guide wheel on the opposite side of the leg structure, and the other end of the internal shape memory alloy wire is wound on the tibial shaft of the leg structure; the leg landing action of each leg structure is driven by an external shape memory alloy wire, one end of the external shape memory alloy wire is fixedly connected with one side of the fuselage on which the leg structure is installed, the external shape memory alloy wire passes through the corresponding external guide wheel on the opposite side of the leg structure, and the other end of the external shape memory alloy wire penetrates through the fuselage bottom plate and is fixedly connected with the middle part of the leg segment of the leg structure.

[0009] Further, the leg structure comprises a tibial segment, a leg segment, a leg segment reset spring, a tibial shaft and a tibial segment reset spring; the tibial shaft is vertically installed in the fuselage, and upper and lower ends thereof are rotationally connected with a cover and a bottom plate of the fuselage respectively, the tibial segment is fixed on the tibial shaft, one end of the tibial segment reset spring is fixedly connected with a side wall of the fuselage, and the other end thereof is fixedly connected with an inner wall of the tibial segment, and an axis of the tibial segment reset spring is perpendicular to the tibial shaft; one end of the leg segment penetrates through the tibial segment, and the leg segment is rotationally connected with the middle part of the tibial segment, one end of the leg segment reset spring is fixedly connected with the one end of the leg segment penetrating through the tibial segment, and the other end thereof is fixedly connected with an end lug of the tibial segment, and an axis of the leg segment reset spring is parallel to the tibial shaft.

[0010] Further, the leg segment comprises a leg segment body; one end of the leg segment body is provided with an extension part, the extension part extends into the tibial segment, and the middle part of the extension part is rotationally connected with the middle part of the tibial segment.

[0011] Further, the internal shape memory alloy wire and the external shape memory alloy wire are made of nickel-titanium alloy.

[0012] Compared with the prior art, the robot has the advantages that:

[0013] 1. The robot is driven by twelve shape memory alloy wires, and each leg structure is controlled by an internal shape memory alloy wire and an external shape memory alloy wire, so that the robot has strong movement ability.

[0014] 2, the tibia of the leg structure is rotated and reset by the internal shape memory alloy wire and the tibia reset spring, the leg is rotated and reset by the external shape memory alloy wire and the leg reset spring, the shape memory alloy wire and the corresponding reset spring form a counter, realize the fast leg and leg action, give full play to the advantages of shape memory alloy wire such as light weight, no noise, large output force and simple control, realize the adaptability of robot to complex environment and task on the basis of simple structure. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the overall structure schematic diagram of the present application;

[0016] Figure 2 It is the structure schematic diagram of the present application without cover;

[0017] Figure 3 It is Figure 2 The top view;

[0018] Figure 4 It is Figure 2 The bottom view;

[0019] Figure 5 It is the leg structure schematic diagram of the present application;

[0020] Figure 6 It is the leg structure explosion diagram of the present application;

[0021] Figure 7 It is the structure schematic diagram of the fuselage of the present application;

[0022] In the figure: 1-fuselage;2-cover;3-leg structure;4-internal guide wheel;5-internal shape memory alloy wire;6-external guide wheel;7-external shape memory alloy wire;

[0023] 101-internal guide wheel connecting seat;102-spring connecting hole;103-microvia;104-tibia shaft connecting hole;301-tibia;302-leg;303-leg reset spring;304-tibia shaft;305-external shape memory alloy wire connecting seat;306-tibia reset spring. DETAILED DESCRIPTION

[0024] The technical solutions of the present application will be described in detail below in combination with the drawings and specific embodiments, but the protection scope of the present application is not limited thereto.

[0025] The present application provides a micro six-legged crawling robot (hereinafter referred to as robot, see Figures 1-7 ) driven by shape memory alloy, which comprises a fuselage 1, a leg structure 3, an internal guide wheel 4, an internal shape memory alloy wire 5, an external guide wheel 6 and an external shape memory alloy wire 7;

[0026] Six leg structures 3 are symmetrically distributed on the left and right sides of the body 1, and the shank shaft 304 of the leg structure 3 is rotatably connected with the body 1. Three internal guide wheels 4 are rotatably installed on the left and right inner walls of the bottom plate of the body 1, and three external guide wheels 6 are rotatably installed on the left and right outer walls of the bottom plate of the body 1. The leg movement of each leg structure 3 is driven by an internal shape memory alloy wire 5. One end of the internal shape memory alloy wire 5 is fixedly connected with one side of the body 1 where the leg structure 3 is installed. After the internal shape memory alloy wire 5 passes through the corresponding internal guide wheel 4 on the opposite side of the leg structure 3, the other end of the internal shape memory alloy wire 5 is wound around the shank shaft 304 of the leg structure 3. When the internal shape memory alloy wire 5 is energized and shrinks, the shank shaft 304 is driven to rotate around the body 1 towards the tail of the robot, so that the shank 301 of the leg structure 3 rotates in the horizontal plane towards the forward direction of the robot, realizing the forward leg movement. Similarly, the landing movement of each leg structure 3 is driven by an external shape memory alloy wire 7. One end of the external shape memory alloy wire 7 is fixedly connected with one side of the body 1 where the leg structure 3 is installed. After the external shape memory alloy wire 7 passes through the corresponding external guide wheel 6 on the opposite side of the leg structure 3, the other end of the external shape memory alloy wire 7 penetrates through the bottom plate of the body 1 and is fixedly connected with the middle part of the leg segment 302 of the leg structure 3. When the external shape memory alloy wire 7 is de-energized, it is in the original length, and the leg segment 302 does not rotate relative to the shank 301. Conversely, when the external shape memory alloy wire 7 is energized and shrinks, it drives the leg segment 302 to rotate downward around the shank 301, realizing landing. Therefore, each leg structure 3 corresponds to an internal shape memory alloy wire 5 and an external shape memory alloy wire 7, and forms a whole with the internal guide wheel 4 and the external guide wheel 6 on the opposite side.

[0027] The leg structure 3 comprises a shank 301, a leg 302, a leg reset spring 303, a shank shaft 304 and a shank reset spring 306; the shank shaft 304 is vertically installed in the body 1, and the upper and lower ends thereof are respectively rotatably connected with the cover 2 and the bottom plate of the body 1; the shank 301 is fixed on the shank shaft 304; one end of the shank reset spring 306 is fixedly connected with the side wall of the body 1, and the other end thereof penetrates through the shank 301 and is fixedly connected with the inner wall of the shank 301; the axis of the shank reset spring 306 is perpendicular to the shank shaft 304 in the spatial position; in the process of forward leg lifting, the shank reset spring 306 is compressed to store elastic potential energy; after the leg lifting is completed, the shank reset spring 306 releases the elastic potential energy to restore the original state, thereby realizing the resetting of the shank 301 and stretching the internal shape memory alloy wire 5 to restore the initial state; the shank reset spring 306 is in opposition to the internal shape memory alloy wire 5; one end of the leg 302 penetrates through the shank 301, and the leg 302 is rotatably connected with the middle part of the shank 301; the other end of the leg 302 is a free end, which is equivalent to a foot; one end of the leg reset spring 303 is fixedly connected with the end of the leg 302 penetrating through the shank 301, and the other end thereof is fixedly connected with the end ear on the inner side of the shank 301; the axis of the leg reset spring 303 is parallel to the shank shaft 304; in the process of landing, the leg reset spring 303 is compressed; after the landing is completed, the leg reset spring 303 restores the initial state, thereby realizing the lifting of the leg 302 and stretching the external shape memory alloy wire 7 to restore the initial state; the leg reset spring 303 is in opposition to the external shape memory alloy wire 7.

[0028] The leg 302 comprises a leg body and an extension provided at one end of the leg body, the extension extends into the shank 301, the middle part of the extension is rotatably connected with the middle part of the shank 301, and the end part of the extension is connected with the leg reset spring 303; the leg body and the extension are provided with the external shape memory alloy wire connecting seat 305 at the intersection thereof.

[0029] The side walls on the left and right sides of the body 1 are symmetrically provided with three notches for installing the leg structure 3; the size of the notches needs to ensure that the leg structure 3 can reciprocatingly rotate within a certain angle range, thereby realizing the leg lifting and leg lifting actions; the bottom plate of the body 1 is provided with a micro through hole 103 and a shank shaft connecting hole 104 at the positions of the notches; the micro through hole 103 is used for the external shape memory alloy wire 7 to pass through, and the shank shaft connecting hole 104 is used for installing the shank shaft 304; the side wall of the body 1 is provided with a spring connecting hole 102 at the position of the notch, which is used for connecting the shank reset spring 306; the bottom plate of the body 1 is provided with an internal guide wheel connecting seat 101 adjacent to the position of the notch, which is used for installing the internal guide wheel 4.

[0030] The internal guide wheel 4 and the external guide wheel 6 are both ceramic wheels without electric conduction; the internal shape memory alloy wire 5 and the external shape memory alloy wire 7 are made of nickel-titanium alloy.

[0031] The working principle and working process of the present application are as follows:

[0032] Taking a single leg structure 3 as an example, the external shape memory alloy wire 7 is in the original length when power off; the external shape memory alloy wire 7 is powered on to make it shrink, drive the leg segment 302 to rotate downward around the shank segment 301, realize landing; then, the internal shape memory alloy wire 5 is powered on to make it shrink, drive the shank segment shaft 304 to rotate around the machine body 1 in the direction of the robot's forward movement, make the leg structure 3 as a whole rotate in the direction of the robot's forward movement, realize stepping forward; after the landing and stepping action is completed, the internal shape memory alloy wire 5 and the external shape memory alloy wire 7 stop power on, the internal shape memory alloy wire 5 restores to the initial state under the action of the shank segment reset spring 306, and the external shape memory alloy wire 7 restores to the initial state under the action of the leg segment reset spring 303. In this way, the internal shape memory alloy wire 5 and the external shape memory alloy wire 7 are powered on and off in a cycle, and the walking of the robot is realized.

[0033] For the whole robot, the movement of the twelve leg structures 3 is controlled, and the voltage of different shape memory alloy wires is controlled according to certain rules, that is, various self-definable gait movements such as triangular gait, ripple gait and turning gait can be realized. Specifically, the triangular gait is a gait of the six-legged crawling robot moving forward quickly on flat ground, and at the same time, two legs on one side and one leg on the opposite side touch the ground, forming an isosceles triangle. The ripple gait is a slow gait of the six-legged crawling robot moving forward stably on a rugged surface, and four legs touch the ground to ensure stability, and the remaining two legs step. The turning gait is as the name implies, under this gait, three legs on one side move synchronously, and three legs on the opposite side are stationary, realizing the turning of the robot. In addition, the robot is equipped with devices such as cameras, sensors, etc., and can perform monitoring, reconnaissance, exploration and other tasks.

[0034] The unmentioned parts of the present application are applicable to the prior art.

Claims

1. A micro hexapod crawling robot driven based on shape memory alloy, characterized in that, The robot comprises a body, leg structures, internal guide wheels, internal shape memory alloy wires, external guide wheels and external shape memory alloy wires; Six leg structures are symmetrically distributed on the left and right sides of the body, and a tibial shaft of each leg structure is rotationally connected with the body; three internal guide wheels are rotationally installed on the inner walls of the left and right sides of the bottom plate of the body, and three external guide wheels are rotationally installed on the outer walls of the left and right sides of the bottom plate of the body; the leg lifting action of each leg structure is driven by an internal shape memory alloy wire, one end of the internal shape memory alloy wire is fixedly connected with one side of the body where the leg structure is installed, the internal shape memory alloy wire passes through the corresponding internal guide wheel on the opposite side of the leg structure, and the other end of the internal shape memory alloy wire is wound on the tibial shaft of the leg structure; the landing action of each leg structure is driven by an external shape memory alloy wire, one end of the external shape memory alloy wire is fixedly connected with one side of the body where the leg structure is installed, the external shape memory alloy wire passes through the corresponding external guide wheel on the opposite side of the leg structure, and the other end of the external shape memory alloy wire penetrates through the bottom plate of the body and is fixedly connected with the middle part of the leg segment of the leg structure; The leg structure comprises a tibial segment, a leg segment, a leg segment return spring, a tibial shaft and a tibial segment return spring; the tibial shaft is vertically installed in the body, and upper and lower ends of the tibial shaft are rotationally connected with a cover and a bottom plate of the body, the tibial segment is fixed on the tibial shaft, one end of the tibial segment return spring is fixedly connected with a side wall of the body, the other end of the tibial segment return spring is fixedly connected with an inner wall of the tibial segment, and an axis of the tibial segment return spring is perpendicular to the tibial shaft; one end of the leg segment penetrates through the tibial segment, and the leg segment is rotationally connected with the middle part of the tibial segment, one end of the leg segment return spring is fixedly connected with the end of the leg segment penetrating through the tibial segment, the other end of the leg segment return spring is fixedly connected with an end lug of the tibial segment, and an axis of the leg segment return spring is parallel to the tibial shaft; The leg segment comprises a leg segment body; one end of the leg segment body is provided with an extension part, the extension part extends into the tibial segment, and the middle part of the extension part is rotationally connected with the middle part of the tibial segment.

2. The micro six-legged crawling robot driven by shape memory alloy according to claim 1, characterized in that, The internal shape memory alloy wires and the external shape memory alloy wires are made of nickel-titanium alloy.

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