CN113400293B - Tensioning integral robot based on variable stiffness springs - Google Patents

Abstract

The invention discloses a tensioning integral robot based on variable stiffness springs, which includes a driving mechanism, a mechanical arm, a stiffness adjustment unit and an air source; the driving mechanism is used to drive the mechanical arm to swing; multiple movable joints of the mechanical arm are equipped with Stiffness adjustment unit; the stiffness adjustment unit includes a soft rubber sleeve, a spring and a ventilation interface; the soft rubber sleeve is wrapped outside the spring, the ventilation interface is connected to the inside of the soft rubber sleeve, and the air source is connected to the ventilation interface, and the air source is used for the rubber The soft cover is inflated to adjust the stiffness of the spring by extrusion, and the stiffness change of the stiffness adjustment unit is used to adjust the change in the range of motion of the corresponding movable joint of the mechanical arm; that is, the present invention only needs to adjust the inflation change of the rubber soft cover to realize the regulation of the spring stiffness , no need for spring replacement, effectively solving the problem of frequent spring replacement in the prior art.

Description

A tensegrity robot based on variable stiffness spring

technical field

The invention relates to the technical field of robots, in particular to a tensegrity robot based on variable stiffness springs.

Background technique

As a new type of robot, continuous robots have broad application prospects in practical engineering fields such as equipment maintenance in narrow spaces and post-disaster search and rescue due to their good environmental integration capabilities. Due to the complexity and uncertainty of the application environment, a combination of rigidity and flexibility is required for continuous robots. However, most serial robots do not yet have this capability.

In order to realize the requirement of combining rigidity and softness of the continuous robot, it can be realized by replacing springs with different stiffnesses. However, the elastic coefficient of each spring is fixed. If it is necessary to change the stress state of the structure, the spring must be replaced, and it is not a simple matter to replace the spring frequently during the work of the robot, which will seriously affect the engineering cycle. Therefore, it is urgently needed A technical solution capable of solving this problem.

Contents of the invention

The purpose of the present invention is to provide a tensegrity robot based on variable stiffness springs, so as to solve the problem of frequent replacement of springs in the prior art.

In order to solve the above technical problems, the present invention provides a tensegrity robot based on variable stiffness springs, including a drive mechanism, a mechanical arm, a stiffness adjustment unit and an air source; the drive mechanism is used to drive the swing of the mechanical arm; A plurality of movable joints of the mechanical arm are provided with the stiffness adjustment unit; the stiffness adjustment unit includes a rubber soft cover, a spring and a ventilation interface; the rubber soft cover is wrapped outside the spring, and the ventilation interface is connected to the The inside of the soft rubber cover is connected, the air source is connected to the ventilation interface, and the air source is used to inflate the soft rubber cover to squeeze and adjust the stiffness of the spring. The stiffness adjustment unit The change in stiffness is used to adjust the change in the range of motion of the corresponding movable joint of the mechanical arm.

In one of the embodiments, the stiffness adjustment unit further includes a hard casing, and the soft rubber cover and the spring are both arranged in a space surrounded by the hard casing.

In one embodiment, the surface of the rubber sheath pressing the spring is provided with a plurality of raised particles, and the plurality of particles are distributed on the surface of the rubber sheath.

In one of the embodiments, the mechanical arm includes a plurality of movable rings and a plurality of telescopic units; the movable ring is provided with a plurality of stiffness adjustment units, and a plurality of stiffness adjustment units are arranged along the movable ring Arranged in a circumferential direction, a plurality of the stiffness adjustment units are all linked with the driving mechanism; a plurality of the telescopic units are connected between two adjacent movable rings, and the plurality of the telescopic units are respectively connected to the corresponding The plurality of stiffness adjustment units adjacent to the two movable rings are linked; the driving mechanism is used to adjust the expansion and contraction of the spring, and the expansion and contraction of the spring is used to adjust the expansion and contraction of the movable ring. The expansion and contraction of the movable ring are used to control the expansion and contraction of the expansion unit.

In one of the embodiments, the movable ring includes a transverse connecting rod and a connecting seat, both ends of the transverse connecting rod are connected with the connecting seat, and both ends of the spring are connected with the connecting seat, so that This circle forms a circle; between any two opposite stiffness adjustment units, the telescopic unit is movably connected to the opposite stiffness adjustment unit through the connecting seat.

In one of the embodiments, the telescopic unit includes two vertical connecting rods, the two vertical connecting rods are arranged in a staggered manner, and the two ends of the two vertical connecting rods are respectively connected to the two ends of the rigidity adjusting unit on different sides. The connecting seat is connected by rotation.

In one of the embodiments, the connecting seat is provided with a perforation, and the direction of the perforation is the same as the circumferential direction of the movable ring; the driving mechanism is provided with a plurality of pull ropes, and the plurality of pull ropes pass The perforations of the plurality of connecting seats, the oppositely arranged connecting seats share a pull cord, and the driving mechanism is used to regulate the change of the tension of the plurality of stay cords, and the change of the tightness of the plurality of stay cords Used to drive the mechanical arm to swing.

The beneficial effects of the present invention are as follows:

Since the soft rubber cover is wrapped outside the spring, the ventilation interface is connected to the inside of the soft rubber cover, and the air source is connected to the ventilation interface. The soft cover is inflated to squeeze and adjust the stiffness of the spring, and the stiffness change of the stiffness adjustment unit is used to adjust the change in the range of motion of the corresponding movable joint of the mechanical arm, that is, the present invention only needs to adjust the inflation change of the rubber soft cover, then The adjustment and control of spring stiffness can be realized without spring replacement, which practically solves the problem of frequent spring replacement in the prior art.

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings used in the implementation will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention. As far as the skilled person is concerned, other drawings can also be obtained based on these drawings on the premise of not paying creative work.

Fig. 1 is a structural representation provided by the present invention;

Fig. 2 is a schematic structural view of part A of Fig. 1;

Fig. 3 is a schematic structural diagram of the stiffness adjustment unit of Fig. 1;

Fig. 4 is a schematic cross-sectional structure diagram of Fig. 3;

Fig. 5 is a schematic diagram of a partial structure of the movable ring in Fig. 1;

Fig. 6 is a schematic structural diagram of the vertical connecting rod in Fig. 1 .

The reference signs are as follows:

10. Driving mechanism; 11. Pull cord;

20. Mechanical arm; 21. Movable ring; 211. Transverse connecting rod; 212. Connecting seat; 213. Perforation; 22. Telescopic unit; 221. Vertical connecting rod;

30. Stiffness adjustment unit; 31. Rubber soft cover; 32. Spring; 33. Ventilation interface; 34. Hard jacket;

40. Air source.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

The present invention provides a tensegrity robot based on variable stiffness springs, the embodiment of which is shown in Figure 1, Figure 3 and Figure 4, including a drive mechanism 10, a mechanical arm 20, a stiffness adjustment unit 30 and an air source 40; the drive mechanism 10 is used to drive the swing of the mechanical arm 20; a plurality of movable joints of the mechanical arm 20 are equipped with a stiffness adjustment unit 30; the stiffness adjustment unit 30 includes a soft rubber cover 31, a spring 32 and a ventilation interface 33; the soft rubber cover 31 is wrapped in a spring 32, the ventilation interface 33 is connected to the interior of the soft rubber sleeve 31, and the air source 40 is connected to the ventilation interface 33. The air source 40 is used to inflate the soft rubber sleeve 31 to squeeze the stiffness of the spring 32. The stiffness adjustment unit 30 The change in stiffness is used to adjust the change in the range of motion of the corresponding movable joint of the mechanical arm 20 .

During application, the change of the input air volume of the air source 40 can be used to adjust the expansion degree of the soft rubber cover 31. The greater the expansion degree of the soft rubber cover 31, the greater the compression degree of the spring 32, thereby strengthening the spring. 32, that is, the range of motion of the corresponding movable joint of the mechanical arm 20 is reduced. Similarly, the smaller the expansion degree of the soft rubber cover 31 is, the smaller the compression degree of the spring 32 will be, thereby reducing the stiffness of the spring 32, namely The range of motion of the corresponding movable joint of the mechanical arm 20 is improved.

Specifically, through the adjustment of the input air volume of the air source 40, the rigidity of some stiffness adjustment units 30 can be controlled to be relatively large, and the stiffness of some stiffness adjustment units 30 can be controlled to be small, so as to control the stiffness of each movable joint position of the mechanical arm 20 to be in different states , which meets the requirements of rigidity and softness of the mechanical arm 20; and since the stiffness of each movable joint of the mechanical arm 20 can be adjusted by itself at this time, it also provides more options for the movement control mode of the mechanical arm 20, thereby satisfying the The usage requirements of more application scenarios.

As shown in FIG. 3 and FIG. 4 , the stiffness adjustment unit 30 further includes a hard casing 34 , and the soft rubber cover 31 and the spring 32 are both arranged in the space surrounded by the hard casing 34 .

After the hard overcoat 34 is set, the installation positions of the soft rubber cover 31 and the spring 32 are fixed, so if the soft rubber cover 31 is in an inflated state, the activity space of the soft rubber cover 31 will be restricted and the soft rubber cover will be strengthened. 31 exerts a pressing force on the spring 32, thereby satisfying the demand for applying stronger pressure to the spring 32.

And this embodiment also preferably arranges the surface of soft rubber cover 31 to squeeze spring 32 to be provided with a plurality of protruding particles (not shown), and a plurality of particles are distributed everywhere on the surface of soft rubber cover 31, thereby further enhancing the The extruding action of rubber soft cover 31 to spring 32.

As shown in Fig. 1, Fig. 2, Fig. 5 and Fig. 6, mechanical arm 20 comprises a plurality of movable rings 21 and a plurality of telescopic units 22; Arranged along the circumferential direction of the movable ring 21, a plurality of stiffness adjustment units 30 are all linked with the drive mechanism 10; a plurality of telescopic units 22 are connected between two adjacent movable rings 21, and the plurality of telescopic units 22 are respectively connected to the corresponding A plurality of stiffness adjustment units 30 adjacent to the two movable rings 21 are linked; the driving mechanism 10 is used to adjust the expansion and contraction of the spring 32, and the expansion and contraction of the spring 32 is used to adjust the expansion and contraction of the movable ring 21, and the expansion and contraction of the movable ring 21 are used It is used to control the expansion and contraction of the expansion unit 22 .

For example, when the driving mechanism 10 controls the spring 32 to be in an extended state, the stiffness adjustment unit 30 will drive the movable ring 21 into an extended state, and the shape change of the movable ring 21 will also drive the telescopic unit 22 to shorten, thereby realizing the mechanical arm 20 shortening controls.

Similarly, when the driving mechanism 10 controls the spring 32 to be in the retracted state, the stiffness adjustment unit 30 can drive the movable ring 21 to be in a retracted state, and the shape change of the movable ring 21 will also drive the telescopic unit 22 to extend, thereby realizing a mechanical Elongation control of the arm 20 .

At this time, it is only necessary to control the changes in the expansion and contraction of each part of the mechanical arm 20 to realize the swing regulation of the mechanical arm. The right swing drive of the mechanical arm 20 can be realized.

As shown in Figure 1, Figure 2 and Figure 5, the movable ring 21 includes a transverse connecting rod 211 and a connecting seat 212, the two ends of the transverse connecting rod 211 are connected with the connecting seat 212, and the two ends of the spring 32 are connected with the connecting seat 212 , so as to form a ring; between any two opposite stiffness adjustment units 30 , the telescopic unit 22 is movably connected to the opposite stiffness adjustment unit 30 through the connecting seat 212 .

After adopting this setting method, if the spring 32 is in a stretched state, the spring 32 will push the connecting seats 212 on both sides to move outward, and each transverse connecting rod 211 will also move outward accordingly, thereby realizing the expansion of the movable ring 21; if the spring 32 In the retracted state, the spring 32 can pull the connecting seats 212 on both sides to move inward, and each transverse connecting rod 211 will also move inward accordingly, thereby realizing the retraction of the movable ring 21 .

As shown in Figure 1 and Figure 2, the telescopic unit 22 includes two vertical connecting rods 221, the two vertical connecting rods 221 are arranged in a staggered manner, and the two ends of the two vertical connecting rods 221 are respectively connected to the connecting seats on different sides of the stiffness adjustment unit 30 212 rotating connections.

Referring to the directions shown in Fig. 1, Fig. 2 and Fig. 6, the two vertical connecting rods 221 are staggered in a cross shape, and the upper end of the first vertical connecting rod 221 is rotationally connected with the upper left connecting seat 212, and the first The lower end of the vertical connecting rod 221 is rotationally connected with the lower right connecting seat 212, the upper end of the second vertical connecting rod 221 is rotationally connected with the upper right connecting seat 212, and the lower end of the second vertical connecting rod 221 is connected with the lower left The connecting seat 212 is rotationally connected.

Therefore, when the movable ring 21 is in the expanded state, the upper ends of the two vertical connecting rods 221 will separate from each other, and the lower ends of the two vertical connecting rods 221 will also separate from each other, thereby realizing the shortening of the telescopic unit 22; When the ring 21 is in the retracted state, the upper ends of the two vertical connecting rods 221 will approach each other, and the lower ends of the two vertical connecting rods 221 will also approach each other, thereby realizing the expansion of the telescopic unit 22 .

As shown in Figure 2 and Figure 5, the connection seat 212 is provided with a perforation 213, and the orientation of the perforation 213 is the same as the circumferential direction of the movable ring 21; The perforation 213 of each connecting seat 212, the opposite connecting seat 212 share a stay rope 11, the driving mechanism 10 is used to regulate the tightness change of a plurality of stay ropes 11, and the tightness change of a plurality of stay ropes 11 is used to drive the mechanical arm 20 swing.

For example, after the driving mechanism 10 controls the pulling rope 11 to be tightened, each movable ring 21 can be tightened, thereby realizing the shortening of the mechanical arm 20, and after the pulling rope 11 is relaxed, the mechanical arm 20 can be easily stretched; therefore, The mechanical arm 20 can be driven to swing only by controlling the degree of tightness of each pull rope 11 .

The above description is a preferred embodiment of the present invention, and it should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered Be the protection scope of the present invention.

Claims (7)

1. A tensioning integral robot based on a variable stiffness spring is characterized in that,

comprises a driving mechanism, a mechanical arm, a rigidity adjusting unit and an air source;

the driving mechanism is used for driving the mechanical arm to swing;

the rigidity adjusting units are arranged at a plurality of movable joint positions of the mechanical arm;

the rigidity adjusting unit comprises a rubber soft sleeve, a spring and a ventilation interface;

the soft rubber sleeve is wrapped outside the spring, the ventilation interface is communicated with the inside of the soft rubber sleeve, the air source is communicated with the ventilation interface, the air source is used for inflating the soft rubber sleeve to squeeze and adjust the rigidity of the spring, and the rigidity change of the rigidity adjusting unit is used for adjusting the movement amplitude change of the mechanical arm corresponding to the movement joint.

2. The tension monolith robot of claim 1, wherein the stiffness adjustment unit further comprises a hard jacket, the rubber soft jacket and the spring both being disposed within a space enclosed by the hard jacket.

3. The tensegrity robot of claim 1, wherein the surface of the rubber sleeve against which the spring is pressed is provided with a plurality of raised particles, the plurality of particles being distributed throughout the surface of the rubber sleeve.

4. The robot as recited in claim 1, wherein,

the mechanical arm comprises a plurality of movable rings and a plurality of telescopic units;

the movable ring is provided with a plurality of rigidity adjusting units, the rigidity adjusting units are arranged along the circumferential direction of the movable ring, and the rigidity adjusting units are linked with the driving mechanism; a plurality of telescopic units are connected between two adjacent movable rings, and are respectively linked with a plurality of rigidity adjusting units of the two adjacent movable rings;

the driving mechanism is used for adjusting the expansion amount of the spring, the expansion of the spring is used for adjusting the expansion and the folding of the movable ring, and the expansion and the folding of the movable ring are used for controlling the expansion and the folding of the expansion unit.

5. The robot as recited in claim 4, wherein,

the movable ring comprises a transverse connecting rod and a connecting seat, wherein the connecting seat is connected to two ends of the transverse connecting rod, and the connecting seat is connected to two ends of the spring so as to form an annular shape;

and the telescopic units are movably connected with the opposite rigidity adjusting units through the connecting seats between any two opposite rigidity adjusting units.

6. The tensegrity robot of claim 5, wherein the telescoping unit includes two vertical connection rods, the two vertical connection rods are staggered, and two ends of the two vertical connection rods are respectively connected with the connection seats on different sides of the rigidity adjusting unit in a rotating manner.

7. The robot as recited in claim 5, wherein,

the connecting seat is provided with a perforation, and the orientation of the perforation is the same as the central axial direction of the movable ring;

the driving mechanism is provided with a plurality of pull ropes, the pull ropes respectively penetrate through the perforations of the connecting seats, the connecting seats which are oppositely arranged share one pull rope, the driving mechanism is used for regulating and controlling the tightness change of the pull ropes, and the tightness change of the pull ropes is used for driving the mechanical arm to swing.

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