Sma artificial muscle high magnification displacement amplification driver based on parallelogram configuration

Abstract

The application discloses a high-magnification displacement amplification driver of an SMA artificial muscle based on a parallelogram configuration and relates to the technical field of drivers.The driver comprises a connecting rod, bolts are arranged through the upper and lower ends of the connecting rod, PCB boards are arranged on the surfaces of the left and right bolts, nuts are threadedly connected to the surfaces of the bolts and located on the surfaces of the PCB boards, through holes are formed in the surfaces of the PCB boards, and SMA wires are connected through the inner cavities of the through holes.The displacement amplification mechanism effectively solves the contradiction between compactness, amplification multiple and mechanical complexity of a traditional amplification mechanism, compared with the structure form and limitations of common displacement amplification mechanisms, the differential amplification mechanism based on the parallelogram frame embeds the triangular amplification principle into the parallelogram hinge structure through a geometric optimization strategy, effectively avoids the volume expansion problem caused by the geometric size limitation of traditional mechanisms, and realizes high-gain displacement amplification in a compact space.

Description

Technical Field

[0001] This invention belongs to the field of actuator technology, and in particular relates to a high-magnification displacement amplification actuator for SMA artificial muscles based on a parallelogram configuration. Background Technology

[0002] Shape memory alloys (SMAs) are materials that exhibit shape memory effects through thermoelastic and martensitic phase transformations and their inverse transformations. Under appropriate thermal activation or mechanical stress, they can undergo reversible shape changes. SMA actuators, with their extremely high power-to-weight ratio, massive output force, near-noise operation, and simple, flexible actuator structure resembling biological muscles, have become the preferred choice for developing lightweight, compact, and high-power-density actuators. In recent years, they have received widespread attention in research fields such as robotics, medical devices, and aerospace technology.

[0003] However, two-way SMA materials have relatively small strain (typically 3%-5%), resulting in small output displacement for actuators constructed from them. This means that two-way SMA materials cannot provide sufficient drive stroke in many practical applications, thus affecting their performance and the breadth of their applications. To increase the displacement stroke of SMA actuators, existing research mainly addresses this issue through two approaches: (1) Enlarged using a spring configuration: The output force of SMA springs is significantly reduced compared to SMA straight wires. While increasing displacement, the advantage of high output force is sacrificed. At the same time, there is a driving lag problem caused by low heat dissipation.

[0004] (2) Enlargement using geometric and mechanical principles: In mechanical design, common displacement amplification mechanisms include lever mechanisms (which amplify displacement by adjusting the lever arm ratio through the fulcrum position), rack and pinion mechanisms (which amplify stroke through gear ratio), linkage mechanisms (which convert rotation or oscillation into amplified linear motion through multi-link combinations), pulley systems (which amplify displacement through a combination of movable and fixed pulleys), screw mechanisms (which convert rotational motion into linear displacement through a lead screw and nut pair with a large lead), and elastic deformation amplification mechanisms (which amplify small displacements by utilizing the deformation of flexible hinges or elastic beams). Since the displacement output by the SMA (Spark Magnetic Actuator) wire is linear, methods such as rack and pinion mechanisms, linkage mechanisms, and screw mechanisms, which amplify the stroke of rotary mechanisms, are not suitable for displacement amplification in SMA. Elastic deformation amplification mechanisms play an important role in microelectromechanical systems (MEMS), piezoelectric actuators, and other smart material applications. These mechanisms achieve larger output strokes by amplifying the input displacement and are widely used in micro-manipulation, optical instruments, and bioengineering. Existing micro-displacement amplification schemes mainly include the lever principle, the triangle amplification principle, and their derived combined mechanisms.

[0005] Integrated mechanical amplification mechanisms, such as those using pulleys to repeatedly rotate and increase the length of the alloy wire to increase the stroke, or using linkages to construct an amplification mechanism to amplify the displacement of the SMA, while achieving displacement amplification, suffer from the following common problems: The magnification factor is positively correlated with the size of the mechanism. When a large magnification factor is required, it is often necessary to construct a multi-stage amplification structure. This not only leads to the expansion of the system size, but also causes the cumulative effect of energy loss due to the growth of the transmission chain.

[0006] Furthermore, these solutions increase the mechanical complexity and manufacturing difficulty of the system, severely diminishing the advantage of the high power-to-weight ratio of the SMA drive.

[0007] To address these issues, we provide a high-magnification displacement amplification actuator for SMA artificial muscles based on a parallelogram configuration. Summary of the Invention

[0008] The purpose of this invention is to provide a high-magnification displacement amplification actuator for SMA artificial muscles based on a parallelogram configuration, which solves the problems existing in the prior art.

[0009] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution.

[0010] This invention is a high-magnification displacement amplification driver for SMA artificial muscle based on a parallelogram configuration, including a connecting rod, with bolts running through both the upper and lower ends of the connecting rod, and a PCB board fitted onto the surface of the two bolts on the left and right sides. Nuts are threaded onto the surface of the bolts and the surface of the PCB board, and a through hole is formed on the surface of the PCB board. An SMA wire runs through the inner cavity of the through hole, and a solder pad is fixedly connected to the surface of the PCB board.

[0011] The invention is further configured such that the connecting rod is made of carbon fiber or aluminum.

[0012] The present invention is further configured such that the connecting rod and the PCB board form a parallelogram.

[0013] The present invention is further configured such that the upper and lower ends of the connecting rod and the left and right ends of the PCB board are provided with round holes for bolts to pass through.

[0014] The invention is further configured such that the pads are soldered to external silicone wires.

[0015] The present invention is further configured such that the connecting rod, PCB board, and SMA wire form a parallelogram differential amplification mechanism, the principle of which is as follows: The parallelogram differential amplifier mechanism evolved from the triangular amplifier mechanism. The principle of triangular amplification is as follows: Figure 2 As shown, That is, the displacement output by the driver, and This is the displacement output by the mechanism. With the hypotenuse length remaining constant, we have: because and Minimal, neglecting second-order infinitesimals , The magnification factor was then obtained:

[0016] However, the triangle is limited by the size of the hinge itself and the issue of manufacturing precision. It's impossible to make it extremely small; to achieve a larger magnification ratio, you need to increase the size. The length of the amplification mechanism would increase the overall size. Similarly, common amplification mechanisms such as bridge, rhombus, and lever types have the problem of difficulty in reducing size. Therefore, the parallelogram differential amplification mechanism can solve the above problems. Depend on Figure 3 As shown, by placing the triangle within the parallelogram, the limitation imposed by the hinge's dimensions on the overall mechanism's dimensions is resolved. In the parallelogram-enlarged mechanism, the principle of triangle enlargement is thus achieved. It can be made extremely small regardless of the size of the hinge itself, thus achieving a large magnification with a small size. Therefore, within the same size, the parallelogram differential amplifier mechanism can achieve a greater magnification, and its simple structure reduces stroke loss caused by mechanism deformation.

[0017] The present invention is further configured based on the principle of parallelogram magnification formed by the connecting rod and the PCB board, such as... Figure 4 As shown, quadrilateral ABCD is a parallelogram frame (hinges are located at points A, B, C, and D). The two ends of the SMA wire are fixed at points E and G respectively. EF is parallel to BD, and the distance between F and G (the installation offset of the SMA wire) is... The length of the BD rod is The length of SMA filament shrinkage is When rod BD swings around hinge B, the angle between it and the y-axis is... ; Based on geometric relationships, the real-time length of the SMA filament satisfy: The relationship between the shrinkage of SMA yarn and the deflection angle is as follows:

[0018]

[0019]

[0020] Design in progress , Approaching 0, we can obtain the Taylor approximation of equation (2):

[0021] in, The angle between rod BD and the y-axis when the frame is in its initial position. set up x Let x be the displacement of the top of the frame in the x-direction. Then, based on geometric relationships, we can calculate... Therefore, it is possible to calculate the framework in x Directional transmission ratio i :

[0022]

[0023]

[0024] Compared to , Since the value is small, the transmission ratio of the frame can be approximated. It can be adjusted and The value is used to obtain the required stroke magnification factor.

[0025] The present invention is further configured such that the output force analysis of the parallelogram differential amplification mechanism composed of the connecting rod, PCB board, and SMA wire is as follows: like Figure 4 As shown, the output force of the actuator at each position is calculated in equilibrium. The angle between the SMA wire (6) and the ground is... The arrow above indicates The force to be determined is the output force of the SMA wire (6) acting on point G. The forces exerted by the ground on rods BD and AC are respectively and The direction is unknown, with the pulling force as the positive direction.

[0026] According to geometric relationships, the angle between the SMA wire (6) and the ground is... achievable Mode have to: Force analysis: Force balance in the x direction

[0027] Force balance in the y direction

[0028] Torque balance around point B

[0029] From equation (8), we can obtain

[0030] Substituting equation (10) into equation (7) yields

[0031] Substituting equation (11) into equation (9) yields

[0032]

[0033]

[0034] Substituting equation (12) into equation (10) yields

[0035]

[0036]

[0037] Substituting equation (6) into equation (11) yields the output force. The tension generated by the SMA filament (6) The ratio is:

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044] because Therefore, the formula We can approximate it as follows:

[0045] Combining the displacement transmission ratio obtained above The conclusion shows that the transmission ratio and the force amplification ratio are reciprocals of each other, which conforms to the physical law of energy conservation.

[0046] The present invention is further configured such that, in order to achieve an efficient driving device, the arrangement of the SMA filaments can be configured with SMA filaments of different diameters simultaneously, and the fine and thick filaments are arranged in parallel to form an SMA artificial muscle module. This not only ensures that the SMA filaments can provide sufficient output force when the shape changes, but also dynamically adjusts the overall response frequency and action cycle of the artificial muscle module composed of SMA filaments according to the response speed of SMA filaments of different diameters. The output force and displacement can be flexibly configured by connecting multiple filaments in parallel and adjusting the offset. The control of the SMA driving system is achieved by integrating current feedback, resistance monitoring and multimodal sensing.

[0047] The present invention has the following beneficial effects.

[0048] 1. The displacement amplification mechanism of this invention effectively solves the contradiction between compactness, amplification factor, and mechanical complexity in traditional amplification mechanisms. Compared with the structural forms and limitations of common displacement amplification mechanisms, the differential amplification mechanism based on a parallelogram frame proposed in this invention, through a geometric optimization strategy, embeds the triangular amplification principle into the parallelogram hinge structure, effectively avoiding the volume expansion problem caused by geometric size limitations in traditional mechanisms, and achieving high-gain displacement amplification in a compact space. Through geometric modeling and Taylor approximation analysis, the displacement transmission ratio of the mechanism proposed in this invention is... ≈ / Its magnification can be adjusted by adjusting the length of the rod. With offset Flexible adjustment allows for customized designs based on actual needs.

[0049] 2. The integrated design of the SMA driver in this invention provides theoretical support. Through structural innovation and parameter optimization, it solves the balance problem between high amplification and low mechanical complexity, laying the foundation for subsequent experimental verification and engineering applications. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0051] Figure 1 This is a schematic diagram of the connection structure of a high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration.

[0052] Figure 2 This is a schematic diagram of the triangular amplification principle of a high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration.

[0053] Figure 3 This is a schematic diagram of the parallelogram differential amplification mechanism in a high-magnification displacement amplification driver for SMA artificial muscles based on a parallelogram configuration.

[0054] Figure 4 This is a schematic diagram of the parallelogram guide mechanism in a high-magnification displacement amplification actuator for SMA artificial muscles based on a parallelogram configuration.

[0055] Figure 5 This is a schematic diagram of the parallelogram displacement amplification principle in a high-magnification displacement amplification actuator for SMA artificial muscles based on a parallelogram configuration.

[0056] Figure 6 This is an isometric view of the piezoelectric ceramic actuator amplification mechanism in Example 2.

[0057] Figure 7 This is a front view of the micro-displacement amplification mechanism of the piezoelectric ceramic actuator amplification mechanism in Example 2.

[0058] Figure 8 An isometric view of the parallelogram differential amplifier mechanism of the piezoelectric ceramic actuator amplifier mechanism in implementation 2.

[0059] Figure 9 This is an isometric view of the parallelogram guide mechanism of the piezoelectric ceramic actuator amplification mechanism in Example 2.

[0060] Figure 10 The square prism in Example 3 Geometric modeling diagram.

[0061] Figure 11 The square prism in Example 3 Ⅰ Surface bends A schematic diagram showing the state before and after the angle.

[0062] Figure 12 The square prism in Example 3 Top surface Torsion occurred A schematic diagram showing the state before and after the angle.

[0063] In the attached diagram: 1. Connecting rod; 2. Bolt; 3. PCB board; 4. Nut; 5. Through hole; 6. SMA wire; 7. Solder pad. Detailed Implementation

[0064] The technical solutions of the present invention will be described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments.

[0065] Example 1 Please see Figures 1-4 The present invention is a high-magnification displacement amplification driver for SMA artificial muscle based on a parallelogram configuration, including a connecting rod 1, with bolts 2 passing through both the upper and lower ends of the connecting rod 1, and a PCB board 3 sleeved on the surface of the two bolts 2 on the left and right sides. Nuts 4 are threadedly connected to the surface of the bolts 2 and the surface of the PCB board 3. A through hole 5 is opened on the surface of the PCB board 3, and an SMA wire 6 is passed through the inner cavity of the through hole 5. A solder pad 7 is fixedly connected to the surface of the PCB board 3.

[0066] Connecting rod 1 is made of carbon fiber or aluminum.

[0067] Connecting rod 1 and PCB board 3 form a parallelogram.

[0068] The upper and lower ends of the connecting rod 1 and the left and right ends of the PCB board 3 are all provided with round holes for the bolts 2 to pass through.

[0069] Pad 7 is soldered to the external silicone wire.

[0070] Connecting rod 1, PCB board 3, and SMA wire 6 form a parallelogram differential amplifier mechanism, the principle of which is as follows: The parallelogram differential amplifier mechanism evolved from the triangular amplifier mechanism. The principle of triangular amplification is as follows: Figure 2 As shown, That is, the displacement output by the driver, and This is the displacement output by the mechanism. With the hypotenuse length remaining constant, we have: because and Minimal, neglecting second-order infinitesimals , The magnification factor was then obtained: However, the triangle is limited by the size of the hinge itself and the issue of manufacturing precision. It's impossible to make it extremely small; to achieve a larger magnification ratio, you need to increase the size. The length of the amplification mechanism would increase the overall size. Similarly, common amplification mechanisms such as bridge, rhombus, and lever types have the problem of difficulty in reducing size. Therefore, the parallelogram differential amplification mechanism can solve the above problems. Depend on Figure 3 As shown, by placing the triangle within the parallelogram, the limitation imposed by the hinge's dimensions on the overall mechanism's dimensions is resolved. In the parallelogram-enlarged mechanism, the principle of triangle enlargement is thus achieved. It can be made extremely small regardless of the size of the hinge itself, thus achieving a large magnification with a small size. Therefore, within the same size, the parallelogram differential amplifier mechanism can achieve a greater magnification, and its simple structure reduces stroke loss caused by mechanism deformation.

[0071] Based on the principle of parallelogram magnification formed by connecting rod 1 and PCB board 3, such as Figure 4 As shown, quadrilateral ABCD is a parallelogram frame with hinges located at points A, B, C, and D. The two ends of the SMA wire are fixed at points E and G respectively. EF is parallel to BD, and the installation offset between F and G and the SMA wire is [missing information]. The length of the BD rod is The length of SMA filament shrinkage is When rod BD swings around hinge B, the angle between it and the y-axis is... ; Based on geometric relationships, the real-time length of the SMA filament satisfy: The relationship between the shrinkage of SMA yarn and the deflection angle is as follows:

[0072]

[0073]

[0074] Design in progress , Since it approaches 0, we can approximate Equation 2 using Taylor's approximation:

[0075] in, The angle between rod BD and the y-axis when the frame is in its initial position. set up x Let x be the displacement of the top of the frame in the x-direction. Then, based on geometric relationships, we can calculate... Therefore, it is possible to calculate the framework in x Directional transmission ratio i :

[0076]

[0077]

[0078] Compared to , Since the value is small, the transmission ratio of the frame can be approximated. It can be adjusted and The value is used to obtain the required stroke magnification factor.

[0079] Output force analysis of the parallelogram differential amplifier mechanism composed of connecting rod 1, PCB board 3, and SMA wire 6: like Figure 4 As shown, the output force of the actuator at each position is calculated in equilibrium. The angle between SMA wire 6 and the ground is... The arrow above indicates The force to be output is the force acting on point G, which is the output force of SMA wire 6. The forces exerted by the ground on rods BD and AC are respectively and The direction is unknown, with the pulling force as the positive direction.

[0080] Based on geometric relationships, the angle between SMA wire 6 and the ground... achievable Mode have to: Force analysis: Force balance in the x direction

[0081] Force balance in the y direction

[0082] Torque balance around point B

[0083] From Equation 8, we can obtain

[0084] Substituting equation 10 into equation 7, we get...

[0085] Substituting equation 11 into equation 9, we get...

[0086]

[0087]

[0088] Substituting equation 12 into equation 10, we get...

[0089]

[0090]

[0091] Substituting Equation 6 into Equation 11 yields the output force. The tension generated by SMA yarn 6 The ratio is:

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] because Therefore, the formula We can approximate it as follows:

[0099] Combining the displacement transmission ratio obtained above The conclusion shows that the transmission ratio and the force amplification ratio are reciprocals of each other, which conforms to the physical law of energy conservation.

[0100] In terms of SMA filament arrangement, to achieve an efficient drive device, SMA filaments of different diameters can be configured simultaneously. The fine and thick filaments are arranged in parallel to form an SMA artificial muscle module. This not only ensures that the SMA filaments can provide sufficient output force when the shape changes, but also dynamically adjusts the overall response frequency and action cycle of the artificial muscle module composed of SMA filaments according to the response speed of SMA filaments of different diameters. The output force and displacement can be flexibly configured through multi-filament parallel connection and offset adjustment. The SMA drive system control is achieved by integrating current feedback, resistance monitoring and multimodal sensing.

[0101] Example 2 Please see Figures 5-9 This invention relates to a piezoelectric ceramic actuator amplification mechanism based on the parallelogram amplification principle, comprising: The parallelogram differential amplifier mechanism is based on the parallelogram amplification principle. The four corners of the parallelogram differential amplifier mechanism are equipped with straight-round flexible hinges. A driver with translational motion is installed at the input end to output the stroke, and the output end of the parallelogram differential amplifier mechanism can output the amplified stroke. The parallelogram guide mechanism has a piezoelectric ceramic actuator installed in its inner cavity. The parallelogram guide mechanism is used to guide the displacement of the piezoelectric ceramic actuator. The bottom end of the parallelogram differential amplifier mechanism and the parallelogram guide mechanism has a mounting hole for fixing with the parallelogram differential amplifier mechanism. The lower and upper parts of the parallelogram guide mechanism have grooves for placing the piezoelectric ceramic actuator. The mounting hole between the parallelogram differential amplifier mechanism and the parallelogram guide mechanism is threaded with fixing and pre-tightening bolts. The fixing and pre-tightening bolts are used to pre-tighten the piezoelectric ceramic actuator. A stainless steel ball is placed between the piezoelectric ceramic actuator and the pre-tightening bolt. The stainless steel ball can effectively reduce the tangential force generated on the piezoelectric ceramic actuator during the operation of the mechanism.

[0102] The top of the inner cavity of the parallelogram differential amplifier mechanism is provided with an arc-shaped contact surface for contacting the top of the parallelogram guide mechanism.

[0103] The top two sides of the parallelogram guide mechanism are equipped with straight-leaf flexible hinges.

[0104] The parallelogram differential amplifier mechanism has threaded fixing bolts on both sides of the bottom surface, which are fixedly connected to external equipment.

[0105] A mounting pad is placed at the bottom of the inner cavity of the parallelogram guide mechanism.

[0106] Because piezoelectric ceramic actuators cannot withstand large tangential forces, a parallelogram guide mechanism is used to eliminate the tangential friction generated by the translational motion of the mechanism, ensuring that the piezoelectric ceramic actuator only bears pressure in the direction of motion. The principle is as follows: Figure 5 As shown; Because the piezoelectric ceramic actuator has a very small stroke, in order to prevent machining and installation errors from affecting the stroke output of the piezoelectric ceramic actuator, the fixing and pre-tightening bolts ensure that the output end of the piezoelectric ceramic actuator is completely in contact with the parallelogram guide mechanism and the parallelogram differential amplifier mechanism.

[0107] Example 3 Please see Figures 10-12 Due to the instability of parallelograms, they can undergo tilting and displacement deformation. This characteristic was utilized to design a quadrangular prism structure, where the deformation of the four sides causes the entire quadrangular prism to deform. This quadrangular prism structure is an optimized version of a parallel structure. A parallel structure is a mechanical system in which multiple independent branches (such as linkages and actuators) connect a moving platform and a stationary platform. The moving platform achieves precise pose control in multi-dimensional space through the coordinated movement of these branches.

[0108] Each face of the quadrangular prism follows the parallelogram deformation principle, similar to the principle of angular displacement amplification, where the small travel distance of the long side of a triangle is amplified into a large travel distance through the short side. Due to the low power conversion rate of SMA filaments and the small size of the SMA artificial muscle modules, the deformation capacity of the SMA artificial muscle is limited. To achieve a larger travel distance, a structure with a certain range of motion is needed. SMA artificial muscle modules are arranged at a certain angle on the sides of the quadrangular prism to form a displacement triangle. When the SMA contracts, it is equivalent to a change in the hypotenuse of the triangle, resulting in displacement amplification on the short side of the quadrangular prism, i.e., a quadrilateral translational deformation.

[0109] The length of the shorter side of the triangle is The length of the long side is When a triangle deforms, that is, when the angle of inclination of the hypotenuse increases, the longer side lengthens. That is, the input displacement of the driver is The side shortened That is, the output displacement of the mechanism is Since the length of the hypotenuse remains unchanged, meaning the side length of the parallelogram remains unchanged, then we have: (1.1) because and Both are extremely small, and their second-order infinitesimals can be ignored. , The magnification can then be obtained. for: (1.2) Geometric modeling like Figure 10 As shown, using a quadrangular prism bottom center Establish a spatial rectangular coordinate system with reference center. The base of the quadrangular prism has a side length of 2. Gao Wei The four sides are labeled as side I, side II, side III, and side IV. Taking side I as an example, the changes in the SMA artificial muscle and its side profile are shown. There are two symmetrical intersecting line segments on side I. and This represents a symmetrically arranged SMA artificial muscle module, allowing us to obtain the coordinates of each point in its initial state. The contraction of the SMA filaments and the bending angle of the quadrangular prism can then be derived from the equations relating their positions. and torsion angle The functional relationship between them is used to verify the controllability of the translational and torsional motions of the quadrangular prism.

[0110] When the SMA artificial muscle actuators on surfaces I and III (or II and IV) deform, causing the parallelograms on surfaces I and III (or II and IV) to deform, bending to the left and right (or forward and backward) can be achieved. Figure 11 The image shows that surface I is bent. The state before and after the angle changes, resulting in a change in coordinates; The original coordinates are: (1.3) After deformation, the coordinates become: (1.4) Original length of SMA yarn for: (1.5) SMA filament length after shrinkage for: (1.6) Then the SMA filament variable can be obtained. for: (1.7) This formula represents the SMA filament shape variable under bending mode. With bending angle The relational expression.

[0111] When the corresponding SMA artificial muscle actuators on surfaces I, II, III, and IV, i.e., those in the same installation direction, undergo the same deformation, causing the parallelograms on surfaces I, II, III, and IV to also undergo the same deformation, then to maintain structural stability, the parallelograms on each side will undergo spatial torsion, thus completing the torsional deformation of the quadrangular prism. Figure 12 The top surface is shown Torsion occurred The state before and after the angle changes, resulting in a change in coordinates; After deformation, the coordinates become:

[0112] (1.8) According to the fixed-point ratio formula, we get Coordinates: (1.9) That is: (1.10) Original length of SMA yarn for: (1.11) SMA filament length after shrinkage for: (1.12) Then the SMA filament variable can be obtained. for: (1.13) This formula represents the SMA filament deformation under torsional mode. With bending angle The relational expression.

Claims

1. A high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration, comprising a connecting rod (1), characterized in that: Bolts (2) are provided through both the upper and lower ends of the connecting rod (1). A PCB board (3) is fitted on the surface of the two bolts (2). Nuts (4) are threaded onto the surface of the bolts (2) and the surface of the PCB board (3). A through hole (5) is opened on the surface of the PCB board (3). An SMA wire (6) is connected through the inner cavity of the through hole (5). A solder pad (7) is fixedly connected to the surface of the PCB board (3).

2. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 1, characterized in that: The connecting rod (1) is made of carbon fiber or aluminum.

3. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 1, characterized in that: The connecting rod (1) and the PCB board (3) form a parallelogram.

4. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 1, characterized in that: The upper and lower ends of the connecting rod (1) and the left and right ends of the PCB board (3) are provided with round holes for the bolts (2) to pass through.

5. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 1, characterized in that: The pad (7) is soldered to the external silicone wire.

6. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 1, characterized in that: The connecting rod (1), PCB board (3), and SMA wire (6) form a parallelogram differential amplifier mechanism. Its principle is as follows: the parallelogram differential amplifier mechanism is evolved from the triangular amplifier mechanism. The principle of triangular amplification is shown in Figure 2. That is, the displacement output by the driver, and This is the displacement output by the mechanism. With the hypotenuse length remaining constant, we have: because and Minimal, neglecting second-order infinitesimals , The magnification factor was then obtained: However, the triangle is limited by the size of the hinge itself and the issue of manufacturing precision. It's impossible to make it extremely small; to achieve a larger magnification ratio, you need to increase the size. The length of the hinge would increase the overall size. Similarly, common amplification mechanisms such as bridge, rhombus, and lever mechanisms all have the problem of difficulty in reducing size. Therefore, the parallelogram differential amplification mechanism can solve the above problems. As shown in Figure 3, by placing the triangle in the parallelogram, the limitation of the hinge size on the overall size of the mechanism is solved. In the parallelogram amplification mechanism, the triangle amplification principle... It can be made extremely small regardless of the size of the hinge itself, thus achieving a large magnification with a small size. Therefore, within the same size, the parallelogram differential amplifier mechanism can achieve a greater magnification, and its simple structure reduces stroke loss caused by mechanism deformation.

7. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 6, characterized in that: Based on the principle of parallelogram magnification formed by the connecting rod (1) and the PCB board (3), as shown in Figure 4, quadrilateral ABCD is a parallelogram frame (the hinges are located at points A, B, C, and D). The two ends of the SMA wire are fixed at points E and G respectively. EF is parallel to BD, and the distance between F and G (the installation offset of the SMA wire) is... The length of the BD rod is The length of SMA filament shrinkage is When rod BD swings around hinge B, the angle between it and the y-axis is... ; Based on geometric relationships, the real-time length of the SMA filament satisfy: The relationship between the shrinkage of SMA yarn and the deflection angle is as follows: Design in progress , Approaching 0, we can obtain the Taylor approximation of equation (2): in, Let BD be the angle between the frame and the y-axis when the frame is in its initial position. x Let x be the displacement of the top of the frame in the x-direction. Then, based on geometric relationships, we can calculate... Therefore, it is possible to calculate the framework in x Directional transmission ratio i : Compared to , Since the value is small, the transmission ratio of the frame can be approximated. It can be adjusted and The value is used to obtain the required stroke magnification factor.

8. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 1, characterized in that: Output force analysis of the parallelogram differential amplifier mechanism composed of the connecting rod (1), PCB board (3), and SMA wire (6): As shown in Figure 4, the output force of the actuator at each position is calculated in equilibrium. The angle between the SMA wire (6) and the ground is... The arrow above indicates The force to be determined is the output force of the SMA wire (6) acting on point G. The forces exerted by the ground on rods BD and AC are respectively and With the direction unknown and the tension force as the positive direction, according to geometric relationships, the angle between the SMA wire (6) and the ground is... achievable From the formula have to: Force analysis: Force balance in the x-direction Force balance in the y direction Torque balance around point B From equation (8), we can obtain Substituting equation (10) into equation (7) yields Substituting equation (11) into equation (9) yields Substituting (12) into equation (10) yields Substituting equation (6) into equation (11) yields the output force. The tension generated by the SMA filament (6) The ratio is: because Therefore, the formula We can approximate it as follows: Combining the displacement transmission ratio obtained above The conclusion shows that the transmission ratio and the force amplification ratio are reciprocals of each other, which conforms to the physical law of energy conservation.

9. The high-magnification displacement amplification actuator for SMA artificial muscle based on a parallelogram configuration according to claim 1, characterized in that: In order to achieve an efficient drive device, the arrangement of the SMA filaments (6) can be configured with SMA filaments (6) of different diameters at the same time. The fine and thick filaments are arranged in parallel to form an SMA artificial muscle module. This not only ensures that the SMA filaments (6) can provide sufficient output force when the shape changes, but also dynamically adjusts the overall response frequency and action cycle of the artificial muscle module composed of SMA filaments (6) according to the response speed of SMA filaments (6) of different diameters. The output force and displacement can be flexibly configured by multi-filament parallel connection and offset adjustment. The control of the SMA drive system is realized by integrating current feedback, resistance monitoring and multimodal sensing.

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