CN112223261B

CN112223261B - Three-freedom-degree actuating structure

Info

Publication number: CN112223261B
Application number: CN202010994858.XA
Authority: CN
Inventors: 杨飞; 岳洪浩; 柏冬; 姜生元; 迟关心
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2022-05-17
Anticipated expiration: 2040-09-21
Also published as: CN112223261A

Abstract

A three-degree-of-freedom actuating structure belongs to the technical field of combined structures of flexible body robots and cluster body robots. The invention solves the problem that the rigidity of the traditional actuating structure can not be changed in real time, so that the rigidity enhancing effect of the traditional actuating structure is obvious and has staged characteristics. The upper connecting substrate is communicated with the lower connecting substrate through an integrated electric/telecommunication circuit, the binary base cell structure comprises two ends and SMA actuators arranged between the two ends, each end is connected with the SMA actuator through a flexible hinge, one end is close to or far away from the other end through the SMA actuators, and the upper connecting substrate rotates along the x-axis direction, rotates along the y-axis direction and moves along the z-axis direction through the actions of the SMA actuators. The addressable programming control of each binary cell structure is realized, and the actuation structure has higher intelligence, flexibility and harsh environment adaptability by exerting the subjective motility of each binary cell structure.

Description

Three-freedom-degree actuating structure

Technical Field

The invention relates to a three-degree-of-freedom actuating structure, and belongs to the technical field of combined structures of flexible body robots and cluster body robots.

Background

In the field of clustered robot research, the present invention mainly focuses on proposing a robot configuration, and then using a large number of such robots to perform a task, such as cluster control, planning or execution, only staying in the application level after the robot configuration is obtained, but only mentions the problem of whether the robots can be clustered by using more compact or miniature basic units or modules.

In the field of flexible robot rigidity enhancement research, most researchers still carry out the rigidity enhancement based on the characteristics of materials, and a small number of researchers use force to resist and realize the rigidity enhancement or use self-locking and friction of the structure to carry out the rigidity enhancement. However, most of the methods or solutions can not realize real-time variable rigidity in the actuating process, so that the rigidity enhancing effect of the method or the solution has a staged characteristic, and further expansion of the application field of the method or the solution is severely restricted.

Disclosure of Invention

The invention aims to solve the problem that the rigidity of the existing actuating structure can not be changed in real time, so that the rigidity enhancing effect of the existing actuating structure is obvious and has staged characteristics, and further provides a three-degree-of-freedom actuating structure.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a three-degree-of-freedom actuating structure comprises an upper connecting substrate, a lower connecting substrate and a plurality of binary basic cell structures arranged between the upper connecting substrate and the lower connecting substrate, wherein the upper connecting substrate is communicated with the lower connecting substrate through an integrated telecommunication/telecommunication circuit, each binary basic cell structure comprises two ends and an SMA (shape memory alloy) driver arranged between the two ends, each end is connected with the SMA driver through a flexible hinge, one end is close to or far away from the other end through the SMA driver, and the upper connecting substrate rotates along the x-axis direction, rotates along the y-axis direction and moves along the z-axis direction through the actions of the SMA drivers.

Furthermore, the SMA actuator comprises an inner shell, an outer shell, a 1-state SMA wire and a 0-state SMA wire, wherein the inner shell and the outer shell are nested and are in sliding connection with each other, the top of the inner shell is connected with the bottom of the outer shell through the 0-state SMA wire, and the bottom of the inner shell is connected with the top of the outer shell through the 1-state SMA wire.

Furthermore, the 0-state SMA wire is installed between the inner shell and the outer shell in a snake-shaped penetrating manner, and two end parts of the 0-state SMA wire are fixedly connected with the top of the inner shell respectively and are connected with the positive electrode and the negative electrode of the power supply respectively.

Furthermore, two ends of the 0-state SMA wire are respectively fixedly arranged on the inner shell through a multi-folded-angle snake-shaped structure.

Furthermore, the 1-state SMA wire is installed between the inner shell and the outer shell in a snake-shaped penetrating manner, and two end parts of the 1-state SMA wire are fixedly connected with the bottom of the outer shell respectively and are connected with the positive electrode and the negative electrode of the power supply respectively.

Furthermore, two ends of the 1-state SMA wire are respectively fixedly arranged on the shell through a multi-folded-angle snake-shaped structure.

Furthermore, an elastic restraint body is arranged between each two adjacent binary base cell structures.

Further, the integrated telecommunication circuit is arranged in an intermediate position of the actuation structure.

Furthermore, the upper connecting substrate and the lower connecting substrate are identical in structure, a plurality of clamping grooves are formed in opposite side faces of the two connecting substrates, and the upper end and the lower end of each binary basic cell structure are correspondingly matched and fixed with the clamping grooves in the two connecting substrates.

Further, several binary base cell structures are arranged in an array form.

Compared with the prior art, the invention has the following effects:

the actuating structure has the characteristic of time-variable rigidity, and can be changed from an approximately rigid structure to an approximately flexible structure. According to the requirement of controlling the compliance, except for the binary cell structures which are necessary for keeping the pose of the actuating structure in the actuating structure, the rigidity of the actuating structure is quickly changed and adjusted by changing different numbers of binary cell structures from a follow-up state to a working state or from the working state to the follow-up state. The following of the binary basic cell structure means that the SMA actuator is in a non-electrified state, and the influence on the motion of other binary basic cell structures can be ignored. The method effectively solves the contradiction between high flexibility and high rigidity.

By the aid of the robot clustering method and the robot clustering system, the robot can be clustered by using smaller or miniature basic units or modules, and the goal of clustered coordinated operation of the robot is achieved.

The addressable programming control of each binary base cell structure can be realized by physically addressing each binary base cell structure, and the actuation structure has higher intelligence, flexibility and harsh environment adaptability by exerting the subjective motility of each binary base cell structure, thereby having wide application prospect in engineering.

Compared with a traditional rigid robot or a flexible robot at the present stage, the flexible actuating structure formed by the binary base cell structure array has the greatest advantages that the flexible actuating structure has very high fault tolerance/residual tolerance characteristics, and the total function or performance of the actuating structure cannot be seriously influenced when a certain number of binary base cell structures break down or do not work.

Drawings

Fig. 1 is a schematic perspective view of the present application (the coordinates x 0, y 0, z 0 and x 1, y 1, z 1 shown in the figure represent coordinate systems with different origins, which facilitates the principle expression of the three-degree-of-freedom actuating mechanism);

FIG. 2 is a schematic front view of a binary cell structure;

FIG. 3 is a schematic structural diagram of a binary cell structure in the 0 state;

FIG. 4 is a schematic structural diagram of a binary basic cell structure in the 1 state;

FIG. 5 is a schematic side view of a 0-state SMA wire;

FIG. 6 is a schematic side view of a state 1 SMA wire;

FIG. 7 is a schematic view of the arrangement of elastic restraints;

fig. 8(a), 8(b), 8(c), and 8(d) are schematic diagrams of four array formats of binary base cell structures, respectively.

Detailed Description

The first embodiment is as follows: the present embodiment is described with reference to fig. 1 to 8, which is a three-degree-of-freedom actuation structure, and includes an upper connection substrate 1, a lower connection substrate 2, and a plurality of binary cell structures 3 installed between the upper connection substrate 1 and the lower connection substrate 2, where the upper connection substrate 1 and the lower connection substrate 2 are communicated through an integrated telecommunication circuit, the binary cell structures 3 include two end heads 31 and SMA actuators 32 arranged between the two end heads 31, and each end head 31 is connected to the SMA actuator 32 through a flexible hinge 33, and the SMA actuators 32 are used to realize the approaching and separating of one end head 31 with respect to the other end head 31, and the SMA actuators 32 are used to realize the rotation of the upper connection substrate 1 along the x-axis direction, the rotation along the y-axis direction, and the movement along the z-axis direction, so as to physically address each binary cell structure 3.

The integrated telecommunication circuit is positioned at the right middle position of the actuating structure. The binary cell structure is a custom concept that enables the approach and the separation of the two tips 31.

The SMA wires used in the SMA actuator 32 are two-way memory alloy wires, i.e., the SMA wires contract and provide tension when energized, and recover to their original lengths after self-cooling when de-energized. The memory alloy wire has certain elasticity at low temperature, and can be stretched and kept at certain tension.

The three degrees of freedom refer to movement in the z-axis and rotation in the x-axis and y-axis, respectively.

The actuating structure has the characteristic of time-variable rigidity, and can be changed from an approximately rigid structure to an approximately flexible structure. According to the requirement of controlling the compliance, except for the binary cell structures 3 which are necessary for keeping the pose of the actuating structure in the actuating structure, the rapid transformation and adjustment of the rigidity of the actuating structure are realized by converting different numbers of binary cell structures 3 from the following state to the working state or from the working state to the following state. The following of the binary basic cell structure 3 means that the SMA actuator 32 is in a non-energized state, and the influence on the motion of other binary basic cell structures 3 is negligible. The method effectively solves the contradiction between high flexibility and high rigidity.

Each binary base cell structure 3 is physically addressed, addressable programming control of each binary base cell structure 3 can be achieved, and the actuation structure can have high intelligence, flexibility and harsh environment adaptability by exerting the subjective motility of each binary base cell structure 3, and has a wide application prospect in engineering.

The SMA actuator 32 in the binary cell structure 3 has a special shape memory effect, and can perform multiple experiments on a single product in an initial design stage.

Compared with a traditional rigid robot or a flexible robot at the present stage, the flexible actuating structure formed by the binary cell structure 3 array has the greatest advantages that the flexible actuating structure has very high fault tolerance/residual tolerance characteristics, and the total function or performance of the actuating structure cannot be seriously influenced when a certain number of binary cell structures 3 break down or do not work.

The SMA actuator 32 comprises an inner shell 321, an outer shell 322, a 1-state SMA wire 323 and a 0-state SMA wire 324, wherein the inner shell 321 and the outer shell 322 are nested and mutually connected in a sliding manner, the top of the inner shell 321 is connected with the bottom of the outer shell 322 through the 0-state SMA wire 324, and the bottom of the inner shell 321 is connected with the top of the outer shell 322 through the 1-state SMA wire 323. By controlling the stretching action of the 1-state SMA wire 323 and the 0-state SMA wire 324, the relative sliding of the inner shell 321 relative to the outer shell 322 is realized, and further the stretching movement of the binary basic cell is realized. In the process of actuation, the 1-state SMA wire 323 and the 0-state SMA wire 324 do not interfere with each other.

The binary basic cell has the action principle that when the binary basic cell is in the 0 state, the power is supplied to the 0 state SMA wire 324, the power provides tensile force and shortens the relative displacement between the inner shell 321 and the outer shell 322, and meanwhile, the 1 state SMA wire 323 is stretched and keeps certain resistance. When the binary basic cell is in the 1 state, the 1-state SMA wire 323 is powered, which provides tension and increases the relative displacement between the inner shell 321 and the outer shell 322. Meanwhile, the 0-state SMA wire 324 is elongated and keeps a certain resistance, so that the binary basic cell structure keeps stable in the actuating process.

When all binary cell structures 3 in the moving structure are in a 0 state, the z-direction displacement of the moving structure is shortest; when all binary cell structures 3 in the active structure are in "1" state, the z-direction displacement of the active structure is longest. That is, the movement in the z-axis direction is experimented by controlling the whole binary basic cell structure 3 to switch from the 0 state to the 1 state or from the 1 state to the 0 state.

The rotation principle in the x-axis and y-axis directions is the same, when the moving structure rotates, the binary base cell structures 3 need to be coordinated in motion, as shown in fig. 1, a row of binary base cell structures 3 farthest away in the y-axis negative direction is moved to be in a 1 state, and a row of binary base cell structures 3 farthest away in the y-axis positive direction is moved to be in a 0 state, so that the rotation around the x-axis is realized. When the binary basic cell structures 3 in the moving structure rotate around the x axis and the y axis simultaneously and move along the z axis, the motion of the connecting substrate 1 on the moving structure is multidimensional composite motion, because the upper connecting substrate 1 is a rigid element, the motion of each binary basic cell structure 3 must ensure the integrity and continuity of the connecting substrate, namely the coordination of deformation, the state control of each binary basic cell structure 3 is realized by physically addressing each binary basic cell structure 3, the corresponding strain coordination equation is satisfied, and finally the composite motion is realized.

The 0-state SMA wire 324 penetrates between the inner shell 321 and the outer shell 322 in a snake shape, and two end parts of the 0-state SMA wire 324 are fixedly connected with the top of the inner shell 321 respectively and are connected with the positive electrode and the negative electrode of the power supply respectively.

The two ends of the 0-state SMA wire 324 are respectively fixed on the inner shell 321 through a multi-folded serpentine structure. By the design, two ends of the 0-state SMA wire 324 are fixed in a multi-fold angle mode, fixing pieces such as screws and nuts are avoided, and the size of the binary base cell structure 3 is effectively reduced. The multi-folding mode is shown in a partial schematic view at P in the figure.

The 1-state SMA wire 323 is installed between the inner shell 321 and the outer shell 322 in a snake-like shape, and two end portions of the 1-state SMA wire 323 are fixedly connected with the bottom of the outer shell 322 respectively and are connected with the positive electrode and the negative electrode of the power supply respectively.

Two ends of the 1-state SMA wire 323 are respectively fixed on the shell 322 through a multi-folded-angle snake-shaped structure. By the design, two ends of the 1-state SMA wire 323 are fixed in a multi-fold angle mode, fixing pieces such as screws and nuts are avoided, and the size of the binary base cell structure 3 is effectively reduced.

An elastic restraint body 4 is arranged between every two adjacent binary base cell structures 3. By the design, the elastic restraint body 4 is used for filling a gap between two adjacent binary basic cell structures 3, and the stability of the actuating structure in the motion process is ensured.

The integrated telecommunication circuit is arranged in the middle of the actuating structure.

The upper connecting substrate 1 and the lower connecting substrate 2 are identical in structure, a plurality of clamping grooves are formed in opposite side faces of the two connecting substrates, and the upper end 31 and the lower end 31 of each binary cell structure 3 are correspondingly matched and fixed with the clamping grooves in the two connecting substrates.

Several binary cell structures 3 are arranged in an array. It can be arranged in various array forms as required.

Claims

1. A three-degree-of-freedom actuating structure is characterized in that: the two-value cell structure comprises an upper connecting substrate (1), a lower connecting substrate (2) and a plurality of two-value cell structures (3) arranged between the upper connecting substrate (1) and the lower connecting substrate (2), wherein the upper connecting substrate (1) is communicated with the lower connecting substrate (2) through an integrated telecommunication/telecommunication circuit, each two-value cell structure (3) comprises two end heads (31) and an SMA driver (32) arranged between the two end heads (31), each end head (31) is connected with the SMA driver (32) through a flexible hinge (33), one end head (31) is close to or far away from the other end head (31) through the SMA driver (32), and the plurality of SMA drivers (32) act to realize the rotation of the upper connecting substrate (1) along the x-axis direction, the rotation along the y-axis direction and the movement along the z-axis direction; the rigidity of the actuating structure is rapidly changed and adjusted by changing different numbers of binary base cell structures (3) from a follow-up state to a working state or from the working state to the follow-up state; the following state refers to that the SMA driver is in a non-electrified state, and the motion influence on other binary basic cell structures is neglected;

the SMA actuator (32) comprises an inner shell (321), an outer shell (322), a 1-state SMA wire (323) and a 0-state SMA wire (324), wherein the inner shell (321) and the outer shell (322) are nested and mutually connected in a sliding manner, the top of the inner shell (321) is connected with the bottom of the outer shell (322) through the 0-state SMA wire (324), and the bottom of the inner shell (321) is connected with the top of the outer shell (322) through the 1-state SMA wire (323);

the 0-state SMA wire (324) is arranged between the inner shell (321) and the outer shell (322) in a snake-shaped penetrating manner, and two end parts of the 0-state SMA wire (324) are fixedly connected with the top of the inner shell (321) respectively and are connected with the positive electrode and the negative electrode of a power supply respectively;

two ends of the 0-state SMA wire (324) are respectively fixedly arranged on the inner shell (321) through a multi-folded-angle snake-shaped structure;

the 1-state SMA wire (323) is arranged between the inner shell (321) and the outer shell (322) in a snake-shaped penetrating manner, and two end parts of the 1-state SMA wire (323) are fixedly connected with the bottom of the outer shell (322) respectively and are connected with a positive electrode and a negative electrode of a power supply respectively;

two ends of the 1-state SMA wire (323) are respectively fixedly arranged on the shell (322) through a multi-folded-angle snake-shaped structure.

2. The three-degree-of-freedom actuation structure of claim 1, wherein: an elastic restraint body (4) is arranged between every two adjacent binary base cell structures (3).

3. The three-degree-of-freedom actuation structure of claim 2, wherein: the integrated telecommunication circuit is arranged in the middle of the actuating structure.

4. A three degree of freedom actuation structure according to claim 1 or 3, characterized in that: the upper connecting substrate (1) and the lower connecting substrate (2) are identical in structure, a plurality of clamping grooves are formed in opposite side faces of the two connecting substrates, and the upper end head (31) and the lower end head (31) of each binary cell structure (3) are correspondingly matched and fixed with the clamping grooves in the two connecting substrates.

5. The three-degree-of-freedom actuation structure of claim 4, wherein: a plurality of binary cell structures (3) are arranged in an array.