A micro-displacement actuator based on flexible body hinge and a displacement adjusting method thereof

Abstract

The application discloses a kind of micro-displacement actuators based on flexible body hinge and its displacement adjustment method, it is related to micro-displacement actuator technical field, including fixed platform, dynamic platform and micro-displacement output platform, the top surface center of the fixed platform is fixedly connected with servo motor, the bottom surface center of the dynamic platform is fixedly connected with linkage shaft sleeve.The application is rotated by the output end of servo motor linkage shaft sleeve, linkage shaft sleeve drives dynamic platform to rotate, so that the axis of connecting rod is no longer perpendicular to dynamic platform, dynamic platform will simultaneously produce along the small movement of connecting rod axis, rotary motion is separated by bearing, and the small displacement of micro-displacement output platform is obtained, the displacement of micro-displacement output platform is directly proportional to the square of servo motor rotation angle, when controlling servo motor rotation smaller deflection angle, the displacement of micro-displacement output platform is smaller, its displacement precision is higher, and the displacement adjustment precision of micro-displacement output platform is improved.

Description

Technical Field

[0001] This invention relates to the field of micro-displacement actuator technology, specifically to a micro-displacement actuator based on a flexible body hinge and its displacement adjustment method. Background Technology

[0002] Miniature actuators are devices that achieve micro-displacement motion. Currently, they are mainly actuated by piezoelectric ceramics, but they have the disadvantage of high cost.

[0003] Of course, there are also mechanical micro-displacement actuators, such as:

[0004] 1. The movement of a large cylinder is achieved by using hydraulic pressure to drive the movement of a small cylinder. However, the multi-cylinder design leads to a complex overall structure, and sealing is also a challenge. As a result, the final micro-displacement output accuracy is insufficient.

[0005] 2. Micro-displacement is achieved through a cam-wedge micro-displacement actuation mechanism. For example, Chinese patent application CN 110346581A discloses a reciprocating micro-displacement actuation device. Although the reciprocating micro-displacement of the mechanism is achieved by using a cam-wedge micro-displacement actuation mechanism, the comprehensive arrangement of cam, multiple wedge blocks, multiple guide rails, etc., makes the reciprocating micro-displacement actuation device have many parts, a complex and complicated structure, and is not streamlined enough.

[0006] Therefore, to achieve micro-displacement output, traditional mechanical micro-displacement actuators mostly sacrifice the simplicity of their overall structure, appearing rather large and complex in both size and internal structure. Furthermore, a practical problem exists: although the goal is the same—to obtain micro-displacement output—in actual use, the numerous components lead to the accumulation of assembly tolerances during assembly, or there may be sealing leakage issues, ultimately resulting in a significant reduction in the accuracy of the micro-displacement output.

[0007] Therefore, designing a mechanical micro-displacement actuator with fewer parts, a simple and compact structure, low cost, and the ability to effectively obtain high-precision micro-displacement output, so as to be different from the expensive piezoelectric ceramic actuator, has been a research direction for technicians in the industry. Summary of the Invention

[0008] The purpose of this invention is to provide a micro-displacement actuator based on a flexible body hinge and its displacement adjustment method, so as to solve the problems mentioned in the background art, that the traditional mechanical micro-displacement actuator has a complex overall structure due to the numerous components, or that the micro-displacement output accuracy is not high due to its own sealing problems.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a micro-displacement actuator based on a flexible body hinge, comprising a fixed platform, a moving platform, and a micro-displacement output platform; a servo motor is fixedly connected to the center of the top surface of the fixed platform, and a linkage sleeve is fixedly connected to the center of the bottom surface of the moving platform. The linkage sleeve is slidably connected to the output end of the servo motor, i.e., it only transmits rotational motion, and can slide in the axial direction; a bearing is installed between the moving platform and the micro-displacement output platform, and the micro-displacement output platform is connected to the moving platform through the bearing; multiple connecting rods are provided between the fixed platform and the moving platform, the top end of the connecting rod is connected to the moving platform, and the bottom end of the connecting rod is connected to the fixed platform. An upper annular groove is formed near the top end of the connecting rod, and a lower annular groove is formed near the bottom end of the connecting rod. The upper annular groove is configured as a first elastic ball joint, and the lower annular groove is configured as a second elastic ball joint. The connecting rod between the first elastic ball joint and the second elastic ball joint is configured as a connecting rod.

[0010] In this invention, a servo motor is mounted on a fixed platform. The output shaft of the servo motor coincides with the axis of the fixed platform. A servo controller sends command pulses to cause the output shaft of the servo motor to rotate at a micro-angle according to the number of pulses. For example, if 3600 pulses are set to control the servo motor to rotate one revolution, and if it is necessary to deflect the servo motor by 1° for displacement adjustment, only 10 pulses need to be sent to the servo motor by the servo controller. The servo motor then controls the platform to adjust the specified deflection angle within a small angle range.

[0011] In some embodiments, when the connecting rod is in a vertical position and perpendicular to the moving platform and the fixed platform, the plane formed by the centers of all the first elastic ball joints is parallel to the plane formed by the centers of all the second elastic ball joints.

[0012] In some embodiments, the bearing is a thrust bearing, located between the top surface of the moving platform and the bottom surface of the micro-displacement output platform, the moving platform is connected to the lower ring of the thrust bearing, and the micro-displacement output platform is connected to the upper ring of the thrust bearing.

[0013] In actual use, after the servo motor rotates by a micro-angle, the moving platform will simultaneously generate a small movement along the axis of the connecting rod. The rotational motion is separated by the thrust bearing, thus obtaining the micro-displacement of the micro-displacement output platform.

[0014] Preferably, the connecting rods are arranged at uniform intervals around the circumference of the fixed platform, and the servo motor is located within the space enclosed by the connecting rods.

[0015] Preferably, the lower annular groove protrudes from the top surface of the fixed platform, and the upper annular groove protrudes from the bottom surface of the moving platform, thereby ensuring that the elastic ball joint is exposed.

[0016] Preferably, the cross-sections of both the lower and upper annular grooves are arc-shaped, and the elastic ball joint constructed by the annular grooves has a stable shape.

[0017] Preferably, there are at least three connecting rods, which are parallel to each other. When there are at least three first elastic ball joints, the centers of the multiple first elastic ball joints are sufficient to form a plane. The moving platform is constrained by the multiple first elastic ball joints and can vertically adjust its displacement on a plane parallel to the fixed platform.

[0018] In the initial state, all the connecting rods are perpendicular to the fixed platform. Therefore, during the deflection of the servo motor, as the rotation angle of the moving platform is adjusted, the deflection angle of the connecting rods is consistent with that of their vertical axis, so the connecting rods remain parallel in different rotation states.

[0019] This invention also proposes a displacement adjustment method for a micro-displacement actuator based on a flexible body hinge, comprising the following steps:

[0020] Step 1: Using the command pulses issued by the servo controller, the servo motor rotates at a micro-angle according to the number of pulses, causing the output end of the servo motor to drive the linkage sleeve to deflect by a specified angle.

[0021] Step 2: Before micro-displacement adjustment, the connection point of the connecting rod on the moving platform corresponds to the connection point of the connecting rod on the fixed platform, and the connecting rod is in a vertical state; after micro-displacement adjustment, the position of the first elastic ball joint deflects at a certain angle, and the connecting rod changes from a vertical state to an inclined state.

[0022] Step 3: When the connecting rod is in a vertical position, the distance between the first and second elastic ball joints in the height direction is equal to the length of the connecting rod; when the connecting rod is in a slightly inclined position, the distance between the first and second elastic ball joints in the height direction is less than the length of the connecting rod.

[0023] Step 4: After micro-displacement adjustment, the connecting rod is in an inclined state. The angle between the connecting rod and its vertical axis is the deflection angle of the servo motor. The height distance between the moving platform and the fixed platform is the projection of the connecting rod onto the vertical axis. When the deflection angle of the servo motor is small, the deviation between the projection of the connecting rod onto the vertical axis and the length of the connecting rod itself is small. Therefore, the vertical displacement adjustment distance of the micro-displacement output platform is small and the accuracy is high. When adjusting the micro-displacement of the micro-displacement output platform, the pulses emitted by the servo controller cause the servo motor to drive the linkage sleeve to deflect by a specified angle. After the linkage sleeve deflects the moving platform by a certain angle, the position of the first elastic ball joint on the moving platform and the position of the second elastic ball joint on the fixed platform no longer correspond in the vertical direction, so that the connecting rod changes from a vertical state to a deflected state.

[0024] Preferably, the relationship between the displacement of the micro-displacement output platform and the rotation angle of the servo motor is as follows:

[0025] (rcosθ-r) 2 +(rcosθ-0) 2 +(-d+l)=l 2 ;

[0026] In the formula, l is the length of the connecting rod, d is the displacement distance of the micro-displacement output platform, and θ is the rotation angle of the servo motor. In order to facilitate the analysis of the relationship between the bearing displacement and the servo motor rotation angle, a coordinate system is established, where the center O of the coordinate system is the center of the moving platform plane, and the center of the fixed platform plane is set as O”. Assuming that the distance from the center of each first elastic ball joint to the center of circle O is r, the distance from the center of each second elastic ball joint to the center of circle O” is also r.

[0027] Preferably, the formula for the displacement distance can be obtained from the relationship between the displacement of the micro-displacement output platform and the rotation angle of the servo motor, as follows:

[0028] d = r 2 *(1-cosθ) / (2l);

[0029] In the formula, d is the displacement distance of the micro-displacement output platform, l is the length of the connecting rod, and θ is the rotation angle of the servo motor. After the servo motor rotates by the angle, the center of the moving platform moves from O to O'. At this time, one of the first elastic ball joints moves from A to A'', and the position of the second elastic ball joint is always B. Let the distance between the center of the first elastic ball joint and the center of the second elastic ball joint of the connecting rod be l. Since the length of the connecting rod is constant, the length of A''B is equal to the length of AB, and the displacement distance formula can be obtained.

[0030] Preferably, if θ is very small, the above displacement distance formula can be transformed into:

[0031]

[0032] In the formula, the displacement distance d of the micro-displacement output platform is proportional to the square of the rotation angle θ of the servo motor. Therefore, through the effect of micro-angle deflection adjustment, the displacement distance d of the micro-displacement output platform can be adjusted to a small value with high resolution. With appropriate configuration of r and l values, such as l = 20mm, r = 10mm, and θ = 1°, the calculated displacement distance is 0.00038mm, which shows that the bearing achieves a very small displacement output.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. In this invention, the servo motor rotates by a specified deflection angle due to the command pulse issued by the servo controller. The output end of the servo motor drives the linkage sleeve to rotate, and the linkage sleeve drives the moving platform to rotate, so that the connecting rod is no longer perpendicular to the moving platform. The moving platform will simultaneously produce a small movement along the axis of the connecting rod. The rotational motion is separated by the bearing, thus obtaining the small displacement of the micro-displacement output platform. The displacement distance of the micro-displacement output platform is proportional to the square of the rotation angle of the servo motor. When the servo motor is controlled to rotate at a small deflection angle, the displacement distance of the micro-displacement output platform is smaller, and its displacement accuracy is higher, thus improving the displacement adjustment accuracy of the micro-displacement output platform.

[0035] 2. In this invention, multiple connecting rods are installed between the fixed platform and the moving platform. The multiple connecting rods form a plane with the support points on the moving platform. The moving platform is constrained by multiple first elastic ball joints and can perform vertical adjustment displacement on a plane parallel to the fixed platform, thereby improving the stability of the moving platform when it moves.

[0036] 3. In this invention, by setting a vertical key on the output shaft of the servo motor and opening a keyway on the inner wall of the linkage sleeve with a length greater than the length of the key, when the servo motor drives the linkage sleeve to rotate synchronously, the moving platform moves in the vertical direction, and the moving platform drives the linkage sleeve to perform vertical displacement. Since the length of the keyway is greater than the length of the key, the linkage sleeve is always sleeved on the output shaft of the servo motor.

[0037] 4. In this invention, there is no need to use hydraulic oil, and there is no sealing problem caused by hydraulic oil leakage;

[0038] 5. In this invention, high-precision micro-displacement output can be obtained through the coordinated arrangement of connecting rods, three platforms, servo motors, bearings, and linkage bushings. The overall components are few, the structure is simple and compact, and each component is easy to purchase and inexpensive. Attached Figure Description

[0039] Figure 1 This is a front view of the overall structure of a micro-displacement actuator based on a flexible body hinge and its displacement adjustment method according to the present invention.

[0040] Figure 2 This is a three-dimensional structural schematic diagram of a micro-displacement actuator based on a flexible body hinge and its displacement adjustment method according to the present invention.

[0041] Figure 3 This is a side sectional view of a micro-displacement actuator based on a flexible body hinge and its displacement adjustment method according to the present invention.

[0042] Figure 4 This is a simplified kinematic diagram of the adjustment state of the micro-displacement output platform in the micro-displacement actuator and displacement adjustment method based on a flexible body hinge according to the present invention.

[0043] Figure 5 This is a mathematical model diagram of the adjustment state of the micro-displacement output platform in the micro-displacement actuator and displacement adjustment method based on a flexible body hinge of the present invention.

[0044] In the diagram: 1. Fixed platform; 2. Connecting rod; 21. First elastic ball joint; 22. Second elastic ball joint; 3. Moving platform; 4. Bearing; 5. Micro-displacement output platform; 6. Linkage bushing; 7. Servo motor. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1

[0047] according to Figure 1 , Figure 2 and Figure 3 As shown: A micro-displacement actuator based on a flexible body hinge includes a fixed platform 1, a moving platform 3, and a micro-displacement output platform 5. A servo motor 7 is fixedly connected to the center of the top surface of the fixed platform 1, and a linkage sleeve 6 is fixedly connected to the center of the bottom surface of the moving platform 3. The output end of the servo motor 7 is slidably connected to the linkage sleeve 6, that is, it only transmits rotational motion and slides axially. A bearing 4 is provided between the top surface of the moving platform 3 and the bottom surface of the micro-displacement output platform 5. The servo motor 7 is chosen as the rotational drive mechanism mainly because the servo motor has very high rotational angle output accuracy and is easy to control precisely, thereby enabling the micro-displacement actuator to obtain high-precision micro-displacement output.

[0048] Multiple connecting rods (unmarked) are provided between the fixed platform 1 and the moving platform 3. The top end of the connecting rod is fixedly connected to the moving platform 3, and the bottom end of the connecting rod is fixedly connected to the fixed platform 1. An upper annular groove (unmarked) is formed near the top end of the connecting rod, and a lower annular groove (unmarked) is formed near the bottom end of the connecting rod. The upper annular groove forms a first elastic ball joint 21, and the lower annular groove forms a second elastic ball joint 22. The connecting rod between the first elastic ball joint 21 and the second elastic ball joint 22 forms a connecting rod 2.

[0049] In this embodiment, the micro-displacement output platform 5 is rotatably connected to the moving platform 3 via the bearing 4. The top end of the connecting rod 2 is fixedly connected to the moving platform 3, and the bottom end of the connecting rod 2 is fixedly connected to the fixed platform 1. A servo motor 7 is fixedly installed on the top of the fixed platform 1. The output shaft axis of the servo motor 7 coincides with the axis of the fixed platform 1. The servo motor rotates by a specified deflection angle through the command pulses issued by the servo controller. For example, it is set to control the servo motor 7 to rotate one revolution with 3600 pulses. If it is necessary to deflect the servo motor 7 by 1° for displacement adjustment, it is only necessary to use the encoder to send 10 pulses to the servo motor 7. The servo motor 7 controls the moving platform 3 to adjust the specified deflection angle within a small angle range.

[0050] The output end of the servo motor 7 is connected to the linkage sleeve 6. A vertical key is provided on the outer wall of the output shaft of the servo motor 7, and a vertical keyway is provided on the inner wall of the linkage sleeve 6. The length of the keyway is greater than the length of the key, and the width of the keyway matches the width of the key. In this embodiment, the linkage sleeve 6 is fixedly connected to the bottom surface of the moving platform 3, and the axis of the linkage sleeve 6 coincides with the axis of the moving platform 3, as well as the axis of the servo motor 7.

[0051] In the initial state, the axis of the connecting rod 2 is perpendicular to the plane of the fixed platform 1 and the moving platform 3 respectively. At this time, the plane formed by the centers of the second elastic ball joints 22 of all the connecting rods 2 is parallel to the plane formed by the centers of the first elastic ball joints 21. After the servo motor rotates by an angle, the moving platform 3 will simultaneously produce a small movement along the axis of the connecting rod 2. The rotational motion is separated by the bearing 4, and the small displacement of the micro-displacement output platform 5 is obtained.

[0052] Example 2

[0053] according to Figure 1 , Figure 2 and Figure 3 As shown, there are at least three connecting rods 2, and the axes of the connecting rods 2 are parallel to each other. The connecting rods 2 are evenly spaced in a circle around the circumference of the fixed platform 1, and the servo motor 7 is located within the space enclosed by the connecting rods 2. The arrangement of the connecting rods 2 and the internal placement of the servo motor 7 make the overall structure neat, and the internal placement of the servo motor 7 also facilitates safety protection.

[0054] In this embodiment, the lower annular groove protrudes from the top surface of the fixed platform 1, and the upper annular groove protrudes from the bottom surface of the moving platform 3. The cross-sections of both the lower and upper annular grooves are arc-shaped, which is beneficial for forming a stable shape.

[0055] In this embodiment, a thrust bearing is preferred for bearing 4. The thrust bearing is located between the top surface of the moving platform 3 and the bottom surface of the micro-displacement output platform 5. The moving platform 3 is fixedly connected to the lower ring of the thrust bearing, and the micro-displacement output platform 5 is fixedly connected to the upper ring of the thrust bearing.

[0056] In the initial state, all connecting rods 2 are perpendicular to the fixed platform 1. Therefore, during the deflection of the servo motor 7, as the rotation angle of the moving platform 3 is adjusted, the deflection angle of the connecting rods 2 and the axis is consistent, so the connecting rods 2 are parallel in different rotation states.

[0057] Example 3

[0058] according to Figure 1-5 As shown, a displacement adjustment method for a micro-displacement actuator based on a flexible body hinge includes the following steps:

[0059] 1) Using the command pulses issued by the servo controller, the servo motor 7 rotates at a micro-angle according to the number of pulses, causing the output end of the servo motor 7 to drive the linkage sleeve 6 to deflect at a specified angle.

[0060] 2) Before the micro-displacement adjustment, the connection point of the connecting rod on the moving platform 3 corresponds to the connection point of the connecting rod on the fixed platform 1, and the connecting rod 2 is in a vertical state. After the micro-displacement adjustment, the position of the first elastic ball joint 21 deflects by a certain angle, and the connecting rod 2 changes from a vertical state to an inclined state.

[0061] 3) When the connecting rod 2 is in a vertical state, the distance between the first elastic ball joint 21 and the second elastic ball joint 22 in the height direction is equal to the length of the connecting rod 2. When the connecting rod 2 is in an inclined state, the distance between the first elastic ball joint 21 and the second elastic ball joint 22 in the height direction is less than the length of the connecting rod 2.

[0062] 4) After micro-displacement adjustment, the connecting rod 2 is in an inclined state. The angle between the connecting rod 2 and the vertical axis is the deflection angle of the servo motor 7. The distance between the moving platform 3 and the fixed platform 1 in the height direction is the projection of the connecting rod 2 on the vertical axis. When the deflection angle of the servo motor 7 is small, the deviation between the projection of the connecting rod 2 on the vertical axis and the length of the connecting rod 2 itself is small. Therefore, the vertical displacement adjustment distance of the micro-displacement output platform 5 is small and the accuracy is high.

[0063] In this embodiment, when adjusting the micro-displacement of the micro-displacement output platform 5, the encoder feeds back the actual pulse of the servo motor to the servo drive. The servo controller sends command pulses to the servo driver. The servo driver converts the received pulse signal into an electrical signal to drive the servo motor 7 to run. This causes the servo motor 7 to drive the linkage sleeve 6 to deflect by a specified angle. After the linkage sleeve 6 drives the rotating platform 3 to deflect by a certain angle, the position of the first elastic ball joint 21 on the moving platform 3 and the position of the second elastic ball joint 22 on the fixed platform 1 no longer correspond in the vertical direction. As a result, the connecting rod 2 changes from a vertical state to a deflected state, that is, the connecting rod 2 changes from the AB position to the A”B position. AB, A”B and AA” form an isosceles triangle. At this time, the height position of the moving platform 3 is the projection length of A”B in the vertical axis direction, that is, the projection of one isosceles side of the triangle onto the other isosceles side. When the vertex angle of the triangle is smaller, the projection length of one isosceles side onto the other isosceles side is larger, and the displacement of the moving platform 3 is smaller.

[0064] Example 4

[0065] according to Figure 2 , Figure 4 and Figure 5 As shown, the relationship between the displacement of the micro-displacement output platform 5 and the rotation angle of the servo motor 7 is as follows:

[0066] (rcosθ-r) 2 +(rcosθ-0) 2 +(-d+l)=l 2 ;

[0067] In the formula, l is the length of the connecting rod 2, d is the displacement distance of the micro-displacement output platform 5, and θ is the rotation angle of the servo motor 7. From the formula relating the displacement of the micro-displacement output platform 5 to the rotation angle of the servo motor 7, the formula for the displacement distance is as follows:

[0068] d = r 2 *(1-cosθ) / (2l);

[0069] In the formula, d is the displacement distance of the micro-displacement output platform 5, l is the length of the connecting rod 2, and θ is the rotation angle of the servo motor 7. If θ is very small, the above displacement distance formula can be transformed into:

[0070] d = r 2 *[1-(1-θ 2 / 2)] / (2l)=r 2 / (4l)*θ 2 ;

[0071] In the formula, the displacement distance d of the micro-displacement output platform 5 is proportional to the square of the rotation angle θ of the servo motor 7. Therefore, through the effect of micro-angle deflection adjustment, the value of the displacement distance d of the micro-displacement output platform 5 is small and the resolution is high.

[0072] In this embodiment, in order to facilitate the analysis of the relationship between the displacement of the micro-displacement output platform 5 and the rotation angle of the servo motor 7, a coordinate system is established, wherein the center O of the coordinate system is the center of the plane of the moving platform 3, and the center of the plane of the fixed platform 1 is set as O”. The distance from the center of each first elastic ball joint 21 to the center of circle O is r, so the distance from the center of each second elastic ball joint 22 to the center of circle O” is also r.

[0073] After the servo motor 7 rotates by an angle, the center of the moving platform 3 moves from O to O'. At this time, one of the first elastic ball joints 21 moves from A to A'', and the position of the second elastic ball joint 22 remains at B. Let the distance between the centers of the first elastic ball joint 21 and the second elastic ball joint 22 of the connecting rod 2 be l. Since the length of the connecting rod 2 remains unchanged, the length of A''B is equal to the length of AB. The displacement distance formula can be obtained. With appropriate configuration of the values ​​of r and l, for example, when l is 20mm, r is 10mm, and θ is 1°, the displacement distance can be calculated to be 0.00038mm. It can be seen from this that the micro-displacement output platform 5 obtains a very small displacement output.

[0074] The usage method and working principle of this device are as follows: First, the encoder feeds back the actual pulse of the servo motor to the servo drive. The servo controller sends command pulses to the servo driver. The servo driver converts the received pulse signal into an electrical signal to drive the servo motor 7 to run, so that the output end of the servo motor 7 drives the linkage sleeve 6 to deflect by a specified angle.

[0075] Then, the linkage sleeve 6 drives the platform 3 to rotate, causing the connecting rod 2 to change from a vertical state to an inclined state;

[0076] Next, the moving platform 3 will simultaneously produce a small movement along the axis of the connecting rod 2. The rotational motion of the moving platform 3 will be corrected by the bearing 4, so that the micro-displacement output platform 5 will produce a small directional displacement.

[0077] When the height of the moving platform 3 is adjusted by the servo motor 7, the height of the moving platform 3 decreases, causing the moving platform 3 to move the linkage sleeve 6 below. By reserving a certain space in the vertical direction of the keyway, the output shaft of the servo motor 7 is always accommodated in the keyway by the keyway, so as to ensure the cooperation between the servo motor 7 and the linkage sleeve 6 when the moving platform 3 moves.

[0078] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A micro-displacement actuator based on a flexible body hinge, characterized in that: It includes a fixed platform (1), a moving platform (3), and a micro-displacement output platform (5); A servo motor (7) is fixedly connected to the center of the top surface of the fixed platform (1), and a linkage bushing (6) is fixedly connected to the center of the bottom surface of the moving platform (3). The linkage bushing (6) is slidably connected to the output end of the servo motor (7). A bearing (4) is installed between the moving platform (3) and the micro-displacement output platform (5), and the micro-displacement output platform (5) is connected to the moving platform (3) through the bearing (4); Multiple connecting rods are provided between the fixed platform (1) and the moving platform (3). The top end of the connecting rod is connected to the moving platform (3), and the bottom end of the connecting rod is connected to the fixed platform (1). An upper annular groove is provided near the top end of the connecting rod, and a lower annular groove is provided near the bottom end of the connecting rod. The upper annular groove is configured as a first elastic ball joint (21), and the lower annular groove is configured as a second elastic ball joint (22). The connecting rod between the first elastic ball joint (21) and the second elastic ball joint (22) is configured as a connecting rod (2), and the connecting rods (2) are parallel to each other.

2. The micro-displacement actuator based on a flexible body hinge according to claim 1, characterized in that: The connecting rods (2) are evenly spaced in a circle around the fixed platform (1), and the servo motor (7) is located within the space enclosed by the connecting rods (2).

3. A micro-displacement actuator based on a flexible body hinge according to claim 1 or 2, characterized in that: The number of connecting rods (2) shall not be less than three.

4. A micro-displacement actuator based on a flexible body hinge according to claim 1, characterized in that: When the connecting rod (2) is in a vertical position and perpendicular to the moving platform (3) and the fixed platform (1), the plane formed by the centers of all the first elastic ball joints (21) is parallel to the plane formed by the centers of all the second elastic ball joints (22).

5. A micro-displacement actuator based on a flexible body hinge according to claim 1, characterized in that: The lower annular groove protrudes from the top surface of the fixed platform (1), and the upper annular groove protrudes from the bottom surface of the moving platform (3). The cross-sections of both the lower and upper annular grooves are arc-shaped.

6. A micro-displacement actuator based on a flexible body hinge according to claim 1, characterized in that: The bearing (4) is a thrust bearing, which is located between the top surface of the moving platform (3) and the bottom surface of the micro-displacement output platform (5). The moving platform (3) is connected to the lower ring of the thrust bearing, and the micro-displacement output platform (5) is connected to the upper ring of the thrust bearing.

7. A displacement adjustment method for a micro-displacement actuator based on a flexible body hinge, characterized in that, The micro-displacement actuator based on a flexible body hinge, as described in any one of claims 1-6, specifically includes the following steps: S1. Using the command pulses issued by the servo controller, the servo motor (7) rotates at a micro-angle according to the number of pulses, causing the output end of the servo motor (7) to drive the linkage sleeve (6) to deflect by a specified angle. S2. Before the micro-displacement adjustment, the connection point of the connecting rod on the moving platform (3) corresponds to the connection point of the connecting rod on the fixed platform (1), and the connecting rod (2) is in a vertical state. After the micro-displacement adjustment, the position of the first elastic ball joint (21) deflects by a certain angle, and the connecting rod (2) changes from a vertical state to a slightly inclined state. S3. When the connecting rod (2) is in a vertical state, the distance between the first elastic ball joint (21) and the second elastic ball joint (22) in the height direction is equal to the length of the connecting rod (2); when the connecting rod (2) is in a slightly inclined state, the distance between the first elastic ball joint (21) and the second elastic ball joint (22) in the height direction is less than the length of the connecting rod (2). S4. After micro-displacement adjustment, the connecting rod (2) is in a slightly tilted state. The angle between the connecting rod (2) and the vertical axis is the deflection angle of the servo motor (7). The distance between the moving platform (3) and the fixed platform (1) in the height direction is the projection of the connecting rod (2) on the vertical axis. When the deflection angle of the servo motor (7) is small, the projection of the connecting rod (2) on the vertical axis and the length deviation of the connecting rod (2) itself are small. The displacement adjustment distance of the micro-displacement output platform (5) in the vertical direction is small and the accuracy is high.

8. The displacement adjustment method for a micro-displacement actuator based on a flexible body hinge according to claim 7, characterized in that, The relationship between the displacement of the micro-displacement output platform (5) and the rotation angle of the servo motor (7) is as follows: (rcosθ-r) 2 +(rcosθ-0) 2 +(-d+l)=l 2 ; In the formula, l is the length of the connecting rod (2), d is the displacement distance of the micro-displacement output platform (5), and θ is the rotation angle of the servo motor (7).

9. The displacement adjustment method for a micro-displacement actuator based on a flexible body hinge according to claim 8, characterized in that, From the formula relating the displacement of the micro-displacement output platform (5) to the rotation angle of the servo motor (7), the formula for the displacement distance is as follows: d=r 2 *(1-cosθ) / (2l); In the formula, d is the displacement distance of the micro-displacement output platform (5), l is the length of the connecting rod (2), and θ is the rotation angle of the servo motor (7).

10. The displacement adjustment method for a micro-displacement actuator based on a flexible body hinge according to claim 9, characterized in that, If θ is very small, the above formula for displacement distance can be transformed into: d=r 2 *[1-(1-θ 2 / 2)] / (2l)=r 2 / (4l)*θ 2 ; In the formula, the displacement distance d of the micro-displacement output platform (5) is proportional to the square of the rotation angle θ of the servo motor (7). Therefore, through the effect of micro-angle deflection adjustment, the displacement distance d of the micro-displacement output platform (5) is adjusted to a small value and has high resolution.

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