A quadruped tensile robot based on excitation vibration and motion control method

Abstract

A quadruped tensegrity robot and motion control method based on excitation vibration belong to the technical field of tensegrity robots. The robot includes a drive arm and an elastic cable. The drive arm includes a drive rod, an eccentric wheel, a motor, and a drive foot. The lower end of each drive rod is provided with a drive foot. The upper ends of the four drive rods are connected by six elastic cables to form an upper square cable structure with diagonals and sides. The middle parts of the four drive rods are connected by six elastic cables to form a lower square cable structure with diagonals and sides. The upper and lower square cable structures do not interfere with each other. Four elastic cables are connected between the upper end of the upper square cable structure and the end points of the lower square cable structure. The sixteen elastic cables form a cubic cable structure. The motor is mounted on the drive rod, and an eccentric wheel is mounted on the output shaft of the motor. The motion control method is implemented based on the quadruped tensegrity robot. The present application has a simple and compact structure and can be used for ground or space exploration.

Description

Technical Field

[0001] The present invention belongs to the technical field of tensioning robots, and in particular relates to a quadruped tensioning robot based on excitation vibration and a motion control method. Background Art

[0002] Tensegrity robots are a key branch of robotics, distinguished by their lightweight, high-strength, foldable nature and high load-bearing capacity. Current tensegrity robot actuation methods primarily include creeping and rolling gaits. However, creeping gaits are slow and difficult to turn, while rolling gaits are faster but less efficient and pose challenges in directional control.

[0003] In summary, the path control of tensioning robots is currently difficult and their movement flexibility is low. They have great prospects in applications such as relatively smooth and flat ground or space exploration. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the present invention provides a quadruped tensegrity robot and motion control method based on excitation vibration, addressing the current difficulties in driving and controlling the path of tensegrity robots. The robot excites its driving arm through vibration, resulting in periodic up-and-down vibrations at the driving foot. Driven by this up-and-down vibration, the driving foot is subjected to an upward reaction force from the ground and a reaction force along the driving arm. The upward reaction force counteracts the robot's own gravity, while the reaction forces along the driving arm combine to propel the robot.

[0005] A four-legged tensioning robot based on excited vibration includes a driving arm and an elastic cable, wherein the driving arm includes a driving rod, an eccentric wheel, a motor and a driving foot; the four driving rods are arranged obliquely and staggered, and the lower end of each driving rod is provided with a driving foot, the high ends of the four driving rods are connected by six elastic cables to form an upper square cable structure with diagonals and sides, and the middle parts of the four driving rods are connected by six elastic cables to form a lower square cable structure with diagonals and sides, and the upper and lower square cable structures do not interfere with each other, and four elastic cables are connected between the high end of the upper square cable structure and the end point of the lower square cable structure, and the sixteen elastic cables form a cubic cable structure, the motor is installed on the driving rod, the output shaft of the motor is perpendicular to the driving rod, and the output shaft of the motor is installed with an eccentric wheel, and the motor is arranged between the middle part of the driving rod and the driving foot.

[0006] A motion control method for a quadruped tensegrity robot based on excitation vibration, the method being implemented based on the quadruped tensegrity robot and comprising:

[0007] S1. Vibration control. The eccentric wheel generates a periodic centrifugal force driven by the motor. This centrifugal force stimulates the movement of the driving arm, thereby obtaining a periodic up and down vibration at the driving foot. Driven by the up and down vibration of the driving foot, the driving foot is subjected to an upward reaction force from the ground and a reaction force along the direction of the driving arm. The upward reaction force is used to offset the robot's own gravity. The reaction forces along the direction of the driving arm combine to propel the robot into motion.

[0008] S2, motion control, achieves movement in different directions by controlling the magnitude of the voltage applied to the motors. When the voltage applied to the four motors is the same and the output shafts of two diagonally opposite motors rotate in opposite directions, the output shafts of one pair of opposing motors rotate inward, while the output shafts of the other pair of opposing motors rotate outward, and the robot maintains its in-place motion. Increasing the voltage of any motor while in-place motion causes the robot to move horizontally.

[0009] When the voltages applied to the four motors are the same and the output shafts of two diagonally opposite motors rotate in opposite directions, the output shafts of the four motors rotate outward or inward, and the robot performs rotational motion.

[0010] The beneficial effects of the present invention compared to the prior art are:

[0011] This application's tensioning robot utilizes a four-rod, sixteen-cable structure, with tensioning connections fixed. Four motors are symmetrically fixed to four drive rods on the tensioning structure's lower, square cable structure. Eccentric wheels are fixed to the motor output shafts, and the drive rods vibrate as the eccentric wheels rotate. A driving foot is located at the bottom of the drive rods to increase friction.

[0012] This application uses an excitation vibration method to achieve drive control. The tensioning robot structure realizes its own elastic decoupling, which greatly reduces the driving difficulty. The robot has a simple structure, is very simple to process and assemble, and is easy to universalize.

[0013] The technical solution of the present application will be further described below with reference to the accompanying drawings and embodiments: BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic perspective view of a quadruped tensegrity robot based on excitation vibration according to some embodiments of the present application;

[0015] Figure 2 for Figure 1 A top view of

[0016] Figure 3 for Figure 1 The main view;

[0017] Figure 4A schematic diagram of a force and motion mode of a quadruped tensegrity robot according to some embodiments of the present application;

[0018] Figure 5 This is a schematic diagram of another force and motion mode of the quadruped tensegrity robot in some embodiments of the present application;

[0019] The following are marked in the figure:

[0020] 1. driving arm, 11. driving rod, 12. eccentric wheel, 13. motor, 14. motor frame, 15. driving foot;

[0021] 2. Elastic cords, 21. First group of elastic cords, 22. Second group of elastic cords, 23. Third group of elastic cords, 24. Fourth group of elastic cords, 25. Fifth group of elastic cords;

[0022] 3. Power supply; 31. Battery; 32. Battery rack;

[0023] 4. Controller, 41. Counterweight plate, 42. Control panel;

[0024] 5. Inertial sensor. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. Unless otherwise specified, the terms used in this application have the common meanings understood by those skilled in the art.

[0026] Figure 1 A quadruped tensegrity robot based on excitation vibration is shown, which comprises a driving arm 1 and an elastic cable 2. The driving arm comprises a driving rod 11, an eccentric wheel 12, a motor 13, a motor frame 14 and a driving foot 15;

[0027] The four driving rods 11 are arranged at an angle and in an staggered manner. A driving foot 15 is provided at the lower end of each driving rod 11. The high ends of the four driving rods 11 are connected by six connecting cables to form an upper square cable structure with diagonals and sides. The middle parts of the four driving rods 11 are connected by six connecting cables to form a lower square cable structure with diagonals and sides. The upper and lower square cable structures do not interfere with each other. Four elastic cables 2 are connected between the high end of the upper square cable structure and the end points of the lower square cable structure. The sixteen elastic cables 2 form a cubic cable structure. The motor 13 is installed on a motor frame 14 fixed on the driving rod 11. The output shaft of the motor 13 is perpendicular to the driving rod 11. An eccentric wheel 12 is installed on the output shaft of the motor 13. The motor 13 is arranged between the middle part of the driving rod 11 and the driving foot 15.

[0028] The connection structure between the elastic cable 2 and the drive arm 1 in this embodiment ensures elastic decoupling of the entire robot. The drive arm 1 and the elastic cable 2 together form a four-bar tensioning structure. This structure has the advantages of decoupling the vibration of the motor that can output eccentric motion, and its simple structure without a transmission mechanism provides fast response speed.

[0029] A three-dimensional diagram of the robot, with the driving rod 11 arranged at an acute angle to the ground.

[0030] A top-down view of the robot shows four drive arms 1 arranged symmetrically around the center, with each pair of drive arms 1 arranged in parallel. Motors 1-3 are mounted on drive rod 11, with the output shaft of motor 13 and drive rod 11 aligned in parallel planes and perpendicular to each other. This configuration has the advantage that the centrifugal force generated by eccentric wheel 12 driven by motor 13 is aligned in the same plane as the direction of the drive arms, ensuring that the drive arms 1 always move in a plane perpendicular to the ground.

[0031] The robot is driven by the motor 13 driving the eccentric wheel 12 to generate centrifugal force, which drives the driving arm 1 to vibrate mechanically, thereby controlling the movement of the robot.

[0032] Exemplarily, the motor 13 is mounted on a motor frame 14 , which is mounted on the driving rod 11 . The motor frame 14 is arranged close to the ground, so as to ensure the stability of the robot's movement.

[0033] For example, the length of each driving foot 15 is equal. The height of each driving foot 15 is much smaller than the height of the entire robot, which reduces weight and improves movement flexibility.

[0034] In some embodiments, the driving foot 15 is a flexible driving foot. The advantage of this design is that it improves the adaptability of the robot to the crawling surface structure.

[0035] Exemplarily, the material of each driving foot 15 is rubber or nano sponge.

[0036] In some embodiments, please refer to Figure 2 An inertial sensor 5 is provided at the intersection of the diagonal elastic cables 2 of the lower square cable structure to detect the robot's motion path and help correct the motion trajectory.

[0037] In some embodiments, please refer to Figure 1The sixteen elastic cables 2 are divided into five groups: the four sides of the upper square cable structure form a first elastic cable group 21; the four sides of the lower square cable structure form a second elastic cable group 22; the three connecting the upper and lower square cable structures form a third elastic cable group 23; the diagonal elastic cables 2 of the upper square cable structure form a fourth elastic cable group; and the diagonal elastic cables 2 of the lower square cable structure form a fifth elastic cable group. The order of elastic coefficients of the five groups, from smallest to largest, is as follows: first elastic cable group 21, second elastic cable group 22, third elastic cable group 23, fourth elastic cable group 24, and fifth elastic cable group 25. This design has the advantage of minimizing the influence of elastic cables 2 that are not parallel to the drive arm 1 on its direction of motion and making the motion of the drive arm 1 closer to that of a lever. Because the plane formed by the second and fifth elastic cable groups 22 and 25 is relatively stable, the inertial sensor 5 obtains accurate data.

[0038] In other embodiments, referring to Figure 1 The robot also includes an inertial sensor 5, a controller 4 and a host computer; the controller 4 includes a counterweight plate 41 and a control board 42, wherein the controller 4 is respectively provided on a pair of opposite driving rods 11, the counterweight plate 41 is provided on the driving rod 11, the control board 42 is provided on the counterweight plate 41, the counterweight plate 41 is installed on the driving rod 11, and the control board 42 is installed on the breeding board 41. The inertial sensor 5 is provided at the intersection of the diagonals of the lower square cable structure for detecting the movement path of the robot. The signal output end of the inertial sensor 5 is connected to the signal input end of the control board 42, and the motor 13 is electrically connected to the control board 42.

[0039] The sixteen elastic cables 2 are divided into five groups: the elastic cables 2 on the four sides of the upper square cable structure constitute a first elastic cable group 21; the elastic cables 2 on the four sides of the lower square cable structure constitute a second elastic cable group 22; the elastic cables 2 connecting the upper and lower square cable structures constitute a third elastic cable group 23; the elastic cables 2 on the diagonals of the upper square cable structure constitute a fourth elastic cable group; and the elastic cables 2 on the diagonals of the lower square cable structure constitute a fifth elastic cable group; the elastic coefficients of the five groups of elastic cables are in the following order from small to large: the first elastic cable group 21, the second elastic cable group 22, the third elastic cable group 23, the fourth elastic cable group 24 and the fifth elastic cable group 25. The advantage of this design is that it reduces the influence of the elastic cable 2 that is not parallel to the driving arm 1 on its movement direction, and makes the movement of the driving arm 1 close to the lever movement. Since the plane formed by the second elastic cable group 22 and the fifth elastic cable group 25 is relatively stable, the inertial sensor 5 can obtain accurate data. The controller 4 is used to receive and analyze the information transmitted by the inertial sensor 5 and the host computer, and then control the magnitude of the voltage applied to the motor 13 to realize the movement of the robot in different directions. The inertial sensor 5 and the control board 42 form a closed-loop control, which can actively correct the trajectory offset of the movement.

[0040] To ensure reliable and stable operation, a power supply 3 is also provided, comprising a battery 31 and a battery holder 32. A power supply 3 is mounted on each of the opposing drive arms 11. The battery holder 32 is mounted in the middle of the drive arm 11, and the battery 31 is mounted in the battery holder 32. The power supply 3 and controller 4 are symmetrically positioned in the middle of the corresponding drive arm 1. The controller 4 and power supply 3 are of the same mass, which ensures the rotational symmetry of the tensioning robot. The power supply 3 supplies power to the motor 13 and the controller 4.

[0041] The robot's translation and rotation are achieved by different arrangements of the speed of the motor 13, and the speed of the robot's movement is achieved by controlling the duty cycle of the motor 13.

[0042] In some embodiments, a motion control method for a quadruped tensegrity robot based on excitation vibration is provided, wherein the method is implemented based on the quadruped tensegrity robot of any of the above embodiments.

[0043] The eccentric wheel 12 installed on the output shaft of the motor 13 generates a periodic centrifugal force driven by the motor 13. When the rotation frequency of the motor 13 is close to the natural frequency of the driving arm 1, the centrifugal force will stimulate the driving arm 1 to move to a certain extent. The centrifugal force of the eccentric wheel 12 driven by the motor 13 can stimulate high-intensity vibration, while ensuring a certain friction strength between the driving foot 15 and the ground, thereby obtaining a periodic up and down vibration at the driving foot 15. Driven by the up and down vibration of the driving foot 15, the driving foot 15 is subjected to an upward reaction force from the ground and a reaction force along the direction of the driving arm 1. The upward reaction force is used to offset the robot's own gravity, and the reaction forces along the direction of the driving arm 1 are combined to drive the robot to move; the inertial sensor 5 arranged at the diagonal corner of the lower square cable structure is used to detect the state of the robot's motion path; the power supply 3 is used to drive the motor 13; the controller 4 is used to receive information transmitted by the inertial sensor 5 and the host computer, which analyzes and processes the information and then issues instructions to control the magnitude of the voltage applied to the motor 13 to achieve movement in different directions;

[0044] The method comprises:

[0045] S1. Vibration control. The eccentric wheel 12, driven by the motor 13, generates a periodic centrifugal force. This centrifugal force excites the motion of the driving arm 1, thereby obtaining a periodic up and down vibration at the driving foot 15. Driven by the up and down vibration of the driving foot 15, the driving foot 15 is subjected to an upward reaction force from the ground and a reaction force along the direction of the driving arm 1. The upward reaction force is used to offset the robot's own gravity. The reaction forces along the direction of the driving arm 1 combine to propel the robot into motion.

[0046] S2, motion control, by controlling the magnitude of the voltage applied to the motor 13 to achieve movement in different directions, when the voltage applied to the four motors 13 is the same and the output shafts of two diagonally opposite motors 13 rotate in opposite directions, the output shafts of one pair of opposite motors 13 rotate inwards, and the output shafts of the other pair of opposite motors 13 rotate outwards, and the robot keeps moving in place, such as Figure 4 As shown by the black bold arrows, the thin arrows indicate the movement direction of each driving foot 15; on the basis of the in-situ movement, increasing the voltage of any motor 13 will cause the robot to move horizontally;

[0047] When the voltages applied to the four motors 13 are the same and the output shafts of the two diagonally opposite motors 13 rotate in opposite directions, the output shafts of the four motors 13 all rotate outwards, and the robot rotates clockwise. Figure 5 As shown, the outward rotation is the rotation of the motor 13 relative to the cubic cable structure, as shown in FIG. Figure 5 As shown by the black bold arrows in the middle, the thin arrows indicate the movement direction of each driving foot 15.

[0048] When the voltages applied to the four motors 13 are the same and the output shafts of the two diagonally opposite motors 13 rotate in opposite directions, the output shafts of the four motors 13 all rotate inward, and the robot rotates counterclockwise. The inward rotation is the direction of the motor 13 relative to the cubic cable structure, which is opposite to the outward rotation.

[0049] The present invention has been disclosed above with reference to preferred embodiments, but this is not intended to limit the present invention. Any person skilled in the art who, without departing from the scope of the technical solution of the present invention, can make slight changes or modifications to the above-disclosed structures and technical contents to produce equivalent embodiments with equivalent changes, all of which still fall within the scope of the technical solution of the present invention.

Claims

1. A quadruped tensegrity robot based on excitation vibration, characterized by: The invention comprises a driving arm (1) and an elastic cable (2), wherein the driving arm comprises a driving rod (11), an eccentric wheel (12), a motor (13), a motor frame (14) and a driving foot (15); the four driving rods (11) are tilted and arranged in a staggered manner, the lower end of each driving rod (11) is provided with a driving foot (15), the upper ends of the four driving rods (11) are connected by six elastic cables to form an upper square cable structure with diagonal lines and sides, and the middle parts of the four driving rods (11) are connected by six elastic cables to form a lower square cable structure with diagonal lines and sides. The invention discloses a square cable structure, wherein the upper and lower square cable structures do not interfere with each other, four elastic cables (2) are connected between the high end of the upper square cable structure and the end point of the lower square cable structure, and the sixteen elastic cables (2) form a cubic cable structure. The motor (13) is installed on a motor frame (14) fixed on the driving rod (11), the output shaft of the motor (13) is perpendicular to the driving rod (11), an eccentric wheel (12) is installed on the output shaft of the motor (13), and the motor (13) is arranged between the middle part of the driving rod (11) and the driving foot (15).

2. The quadruped tensegrity robot based on excitation vibration according to claim 1, characterized in that: The material of each driving foot (15) is rubber or nano sponge.

3. The quadruped tensegrity robot based on excitation vibration according to claim 1, characterized in that: Inertial sensors (5) are provided at the intersections of the diagonal elastic cables (2) of the lower square cable structure to detect the motion path of the robot.

4. The quadruped tensegrity robot based on excitation vibration according to claim 1, characterized in that: The sixteen elastic cables (2) are divided into five groups: the elastic cables (2) on the four sides of the upper square cable structure form a first elastic cable group (21); the elastic cables (2) on the four sides of the lower square cable structure form a second elastic cable group (22); the elastic cables (2) connecting the upper and lower square cable structures form a third elastic cable group (23); the elastic cables (2) on the diagonals of the upper square cable structure form a fourth elastic cable group; and the elastic cables (2) on the diagonals of the lower square cable structure form a fifth elastic cable group; the elastic coefficients of the five groups of elastic cables are arranged in the following order from small to large: the first elastic cable group (21), the second elastic cable group (22), the third elastic cable group (23), the fourth elastic cable group (24), and the fifth elastic cable group (25).

5. The quadruped tensegrity robot based on excitation vibration according to claim 1, characterized in that: The robot further comprises an inertial sensor (5), a controller (4) and a host computer; The controller (4) comprises a counterweight plate (41) and a control plate (42), wherein the controller (4) is respectively provided on a pair of opposite driving rods (11), the counterweight plate (41) is provided on the driving rod (11), and the control plate (42) is provided on the counterweight plate (41), the counterweight plate (41) is mounted on the driving rod (11), and the control plate (42) is mounted on the counterweight plate (41), an inertial sensor (5) is provided at the intersection of the diagonals of the lower square cable structure, and is used to detect the motion path of the robot, a signal output end of the inertial sensor (5) is connected to a signal input end of the control plate (42), and a motor (13) is electrically connected to the control plate (42).

6. The quadruped tensegrity robot based on excitation vibration according to claim 5, characterized in that: The sixteen elastic cables (2) are divided into five groups: the elastic cables (2) on the four sides of the upper square cable structure form a first elastic cable group (21); the elastic cables (2) on the four sides of the lower square cable structure form a second elastic cable group (22); the elastic cables (2) connecting the upper and lower square cable structures form a third elastic cable group (23); the elastic cables (2) on the diagonals of the upper square cable structure form a fourth elastic cable group; and the elastic cables (2) on the diagonals of the lower square cable structure form a fifth elastic cable group; the elastic coefficients of the five groups of elastic cables are arranged in the following order from small to large: the first elastic cable group (21), the second elastic cable group (22), the third elastic cable group (23), the fourth elastic cable group (24), and the fifth elastic cable group (25).

7. The quadruped tensegrity robot based on excitation vibration according to claim 5, characterized in that: The translation and rotation of the robot are realized by different arrangements of the rotation speed of the motor (13), and the speed of the robot movement is realized by controlling the duty cycle of the motor (13).

8. The quadruped tensegrity robot based on excitation vibration according to claim 1, characterized in that: The length of each driving foot (15) is equal.

9. A motion control method for a quadruped tensegrity robot based on excitation vibration, characterized in that: The method is implemented based on the quadruped tensegrity robot according to any one of claims 1 to 8, and the method comprises: S1. Vibration control. The eccentric wheel (12) generates a periodic centrifugal force driven by the motor (13). The centrifugal force excites the driving arm (1) to move, thereby obtaining a periodic up and down vibration at the driving foot (15). Driven by the up and down vibration of the driving foot (15), the driving foot (15) is subjected to an upward reaction force from the ground and a reaction force along the direction of the driving arm (1). The upward reaction force is used to offset the robot's own gravity. The reaction forces along the direction of the driving arm (1) are combined to drive the robot to move. S2, motion control, achieving motion in different directions by controlling the magnitude of the voltage applied to the motor (13), when the voltage applied to the four motors (13) is the same and the output shafts of two diagonally opposite motors (13) rotate in opposite directions, the output shafts of one pair of two opposite motors (13) rotate inwards, and the output shafts of the other pair of two opposite motors (13) rotate outwards, and the robot maintains in-situ motion; on the basis of in-situ motion, increasing the voltage of any one of the motors (13) causes the robot to move in a linear manner; When the voltages applied to the four motors (13) are the same and the output shafts of two diagonally opposite motors (13) rotate in opposite directions, the output shafts of the four motors (13) all rotate outward or inward, and the robot performs a rotational motion.

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