CN114083574B

CN114083574B - Vibration suppression actuator of cantilever beam type robot end actuating mechanism

Info

Publication number: CN114083574B
Application number: CN202111472497.3A
Authority: CN
Inventors: 单小彪; 宋赫男; 孙凯威; 韩承硕; 谢涛
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2021-12-06
Filing date: 2021-12-06
Publication date: 2023-07-07
Anticipated expiration: 2041-12-06
Also published as: CN114083574A

Abstract

The invention discloses a vibration suppression actuator of an end actuator of a cantilever beam type robot, belongs to the technical field of vibration suppression, and aims to solve the problem that bending vibration of the end actuator of the robot simplified to be of a cantilever beam structure affects positioning accuracy when the end actuator of the robot is excited and actuated externally. The two ends of a piezoelectric stack of a driving element of the actuator are connected with wedge blocks, under the driving of a control system, the output force of the piezoelectric stack converts the axial force into bending moment of the end actuator through a bracket, so that vibration of the end actuator is restrained, and the problem of hysteresis nonlinearity of cantilever low-frequency vibration is solved through the high response characteristic of piezoelectric materials. The vibration suppression actuator of the cantilever robot end actuating mechanism has the advantages of novel structure and flexible design, and provides a wedge block and bracket combined structure, and the d33 mode piezoelectric stack with higher piezoelectric coefficient is applied to the vibration suppression of the cantilever for the first time, so that the bending vibration of the cantilever can be effectively suppressed.

Description

Vibration suppression actuator of cantilever beam type robot end actuating mechanism

Technical Field

The invention relates to a cantilever beam vibration suppression actuator, in particular to a vibration suppression actuator of a cantilever beam type robot end actuating mechanism, and belongs to the technical field of vibration suppression.

Background

In recent years, from advanced manufacturing to robot automation, mechanical structures and industrial products are increasingly speeded up, intelligentized and flexible so as to meet the market demands of high efficiency, comfort, energy conservation and environmental protection. Therefore, vibration control is an important issue to be considered when performing operations, for devices with complicated working operations or devices with certain requirements for precision and stability. The end actuating mechanism of the robot with the cantilever beam structure mainly can generate forced vibration due to the change of the motion state of the end actuating mechanism in the motion process or at the end of the motion, and redundant vibration is generated due to the flexibility of the end actuating mechanism, so that the motion is failed or potential safety hazards exist.

In the prior art, the vibration of the end effector is difficult to be restrained by closed-loop control under the influence of the working environment of the end effector. The trajectory planning can only inhibit the vibration of the robot to a certain extent, and it is difficult to realize the vibration inhibition of the end effector of the cantilever structure. Meanwhile, as the end effector is directly contacted with the component, nonlinear vibration suppression of the structure is difficult to realize on the basis that the structure of the end effector is not damaged in a passive vibration isolation mode. According to the invention, through the structure of the externally-added actuator, the d33 mode piezoelectric stack with higher piezoelectric coefficient is applied to the vibration suppression of the cantilever beam for the first time, and the vibration suppression of the end execution structure of the cantilever beam type robot with a certain thickness and a larger size is effectively performed by utilizing the characteristics of high response and large output force of the piezoelectric material.

Disclosure of Invention

The invention provides a vibration suppression actuator of an end actuator of an cantilever beam type robot, which aims to solve the problem that the positioning accuracy is affected by bending vibration when the end actuator is excited and actuated externally by using a piezoelectric stack as an actuator on the basis of not damaging the structure of the end actuator.

A vibration suppression actuator of an end effector of a cantilever beam robot includes a piezoelectric stack, a wedge, a platen, a support, and an outer frame.

Two output ends of the piezoelectric stack are connected with the plane sides of the wedge blocks through limit holes, and limit grooves with the diameter depth smaller than the width edges of the wedge blocks are formed in the upper surfaces of the two wedge blocks and used for installing and fixing the pressing plates. The clamp plate is interference fit with the spacing groove, and the clamp plate upper surface is connected with the support minor face. The lower surface of the pre-tightening bolt is fixed on the bracket through the threaded hole and is contacted with the upper surface of the pressing plate. When the pretension bolt is tightened down along the thread, downward pressure is generated against the platen. When the pressing plate is stressed, the pressing wedge blocks slide downwards along the inclined planes of the brackets, the distance between the two wedge blocks is reduced, and the piezoelectric stack is pre-tensioned. The outer frame is sleeved on the outer layer of the support and is fixedly installed through the fixing bolts, so that a protection effect is achieved.

Preferably: the bracket comprises two L-shaped structures and a sleeve structure, and the three structures are processed into an integral structure.

Preferably: the slope of the wedge-shaped block slope is the same as that of the L-shaped structure slope, the contact is tight, the surface machining precision is high, and the friction resistance is small when the wedge-shaped block slides along the surface.

Preferably: the piezoelectric stack adopts a piezoelectric stack with a polarization mode of d33, and the output direction is the axial direction of the bracket and the axial direction of the end actuating mechanism.

Compared with the existing products, the invention has the following effects:

1. and the d33 mode with a larger piezoelectric coefficient is utilized for driving the actuator, so that the maximum output force under the same driving voltage is ensured while the quick response of the actuator is ensured.

2. The cantilever beam vibration suppression actuator has novel structure and flexible design, and provides the cantilever beam type robot end actuator which can ensure that vibration suppression is performed on the basis of not damaging the structure of the end actuator;

3. the vibration suppression actuator converts output force along the axial direction into bending moment for the cantilever structure through the ingenious mechanical structure of the actuator by utilizing the high response characteristic of the piezoelectric stack aiming at the forced vibration and the redundant vibration of the cantilever structure. Vibration suppression is performed by a bending moment opposite to the vibration direction without changing the structure of the end effector. Meanwhile, due to the rapid response of the piezoelectric material, the low-frequency nonlinear vibration of the end effector can be solved through the control system. Avoiding the problems of structural change and response delay of the end actuating mechanism in the current research.

Drawings

FIG. 1 is a schematic diagram of a vibration suppression actuator for an end effector of an cantilever-type robot;

FIG. 2 is an external view of a vibration suppression actuator of an end effector of an cantilever-type robot;

FIG. 3 is a three-dimensional block diagram of a vibration suppression actuator of an end effector of an cantilever-type robot;

FIG. 4 is an exploded view of a vibration suppression actuator of an end effector of an cantilever-type robot;

in the figure: 1-first pretension bolt, 2-clamp plate, 3-second pretension bolt, 4-frame, 5-fixing bolt, 6-right wedge, 7-piezoelectricity stack, 8-left wedge, 9-support, 10-wire, 11-L shape structure, 12-rectangle cavity sleeve structure.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 3, a vibration suppression actuator of an end effector of an cantilever robot according to the present invention includes: d33 piezoelectric stack 7, right wedge 6, left wedge 8, bracket 9 and platen 2;

two output ends of the piezoelectric stack 7 are connected with plane sides of the right wedge-shaped block 6 and the left wedge-shaped block 8 through limiting holes, and limiting grooves with the diameter depth smaller than the width edges of the wedge-shaped blocks are formed in the upper surfaces of the right wedge-shaped block 6 and the left wedge-shaped block 8 and are used for installing and fixing the pressing plate 2.

Further: the pressing plate 2 is in interference fit with the limiting groove, and the upper surface of the pressing plate 2 is connected with the short side of the bracket 9. The lower surface of the first pre-tightening bolt 1 is fixed on the bracket through a threaded hole and is contacted with the upper surface of the pressing plate 2. When the first pretensioning bolt 1 is screwed down along the thread, a downward pressure is generated on the pressing plate 2. When the pressing plate 2 is stressed, the wedge blocks 6 and 8 are pressed to slide downwards along the inclined plane of the bracket 2, the distance between the right wedge block 6 and the left wedge block 8 is reduced, the piezoelectric stack 7 is pre-tensioned, and two ends of the lead (10) are connected with the driver.

Further: the outer frame 4 is sleeved on the outer layer of the bracket 2 and is fixedly installed through the fixing bolts 5, so that the protection effect is achieved.

The present embodiment is only illustrative of the present patent, and does not limit the scope of protection thereof, and those skilled in the art can also change the part thereof, which is not beyond the spirit of the present patent, and is within the scope of protection of the present patent.

Claims

1. The utility model provides a vibration suppression executor of cantilever beam type robot end actuating mechanism which characterized in that: the piezoelectric ceramic comprises a d33 piezoelectric stack (7), a right wedge block (6), a left wedge block (8), a bracket (9) and a pressing plate (2);

one end of the d33 piezoelectric stack (7) is connected with the bracket (9) through the right wedge block (6) and the left wedge block (8); the pressing plate (2) is arranged on the right wedge block (6) and the left wedge block (8), and the upper surface of the pressing plate (2) is contacted with the first pre-tightening bolt (1) and the second pre-tightening bolt (3); the bracket (9) consists of two L-shaped structures (11) and a rectangular hollow sleeve structure (12) and the actuator is arranged on the end actuating mechanism through the sleeve of the bracket (9); the lead (10) is connected with the controller, and the other side of the lead is connected with the two sides of the d33 piezoelectric stack (7); the outer frame (4) is arranged outside the two L-shaped structures (11) of the bracket (9) and is positioned and fastened through the fixing bolts (5).

2. The vibration-damping actuator of an end effector of an cantilever-type robot of claim 1, wherein: the working mode of the piezoelectric stack is d33 mode, the polarization direction is parallel to the axial direction of the end actuating mechanism, and the installation mode is that the output force of the piezoelectric stack is perpendicular to one side of the planes of the right wedge block (6) and the left wedge block (8) and is positioned through the limiting hole.

3. The vibration-damping actuator of an end effector of an cantilever-type robot of claim 1, wherein: d33 piezoelectric stack (7) is fixed in two L-shaped structures (11) of bracket (9) through right wedge (6) and left wedge (8) and clamp plate (2).

4. The vibration-damping actuator of an end effector of an cantilever-type robot of claim 1, wherein: the component consisting of the piezoelectric stack, the wedge block and the pressing plate is screwed by the first pre-tightening bolt (1) and the second pre-tightening bolt (3) so that the structure slides up and down along the inclined plane of the bracket (9).

5. The vibration-damping actuator of an end effector of an cantilever-type robot of claim 1, wherein: the inner surface of the outer frame (4) is in surface contact with the two L-shaped structures (11) of the bracket (9), and no force is applied to the rectangular hollow sleeve structure (12) of the bracket (9).

6. The vibration-damping actuator of an end effector of an cantilever robot of claim 5, wherein: the bracket (9) consists of two L-shaped structures (11) and a rectangular hollow sleeve structure (12), and the two structures are integrated.