Two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output

Abstract

A two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output belongs to the technical field of precision operation and comprises a rotary stick-slip motion platform, a connecting piece and a stick-slip micro-clamping device. The rotary stick-slip motion platform comprises a base, a multidirectional flexible piezoelectric driving mechanism and a rotating part; the rotating part and the multidirectional flexible piezoelectric driving mechanism are mounted on the base, and the rotating part can rotate relative to the base; the output end of the multidirectional flexible piezoelectric driving mechanism is in contact with the peripheral side surface of the rotating part; the multi-directional compliant piezoelectric driving mechanism realizes multi-step superposed large-stroke motion of the rotating part under the action of periodic driving voltage, and the multi-directional compliant piezoelectric driving mechanism realizes precise positioning motion of a smooth track of the rotating part under the action of smooth driving voltage; the connecting piece is installed on the rotating piece, the stick-slip micro gripper is installed on the connecting piece, and constant-force output clamping operation can be achieved. The method has the advantages of high precision, large single-step displacement and stick-slip rollback motion inhibition, and has good motion stability.

Description

Technical Field

[0001] This invention relates to micromanipulators, specifically to a two-degree-of-freedom piezoelectric stick-slip microclamping system with constant force output. It belongs to the field of precision manipulation technology. Background Technology

[0002] As research focuses on more specific applications, microgrippers play an increasingly important role in precision micromanipulation tasks and are widely used in fields such as micro-part assembly, fiber optic splicing, biopharmaceuticals, and microsurgery. The driving methods for microgrippers are becoming increasingly diverse, primarily including piezoelectric actuation, shape memory alloy actuation, vacuum actuation, electrostatic comb actuation, thermal actuation, and electromagnetic actuation. Among these, piezoelectric actuation offers advantages such as high resolution, large driving force, fast response speed, and good dynamic characteristics compared to other actuation methods, and is widely used in microgrippers. Furthermore, to improve operational accuracy and working stroke, microgrippers often employ compliant mechanisms for transmission and displacement amplification. Compliant mechanisms are directly machined by wire cutting, eliminating the need for assembly. Transmission is achieved through the elastic deformation of flexible hinges, avoiding assembly errors and frictional energy loss, thus significantly improving the operational accuracy of the microgripper. Commonly used compliant displacement amplification mechanisms include bridge amplification mechanisms, dual-rocker amplification mechanisms, and lever amplification mechanisms. These mechanisms amplify displacement, increasing the working stroke of the microgripper. Piezoelectric direct-push microgrippers can achieve high operational precision, typically reaching micro-nano-level positioning accuracy. However, a drawback of direct-push microgrippers is their limited stroke, usually only a few hundred micrometers, which restricts their application in cross-scale micromanipulation. In contrast, stick-slip driven microgrippers combine the advantages of high precision and large stroke, gradually becoming a research hotspot in the field of precision micromanipulation. The working principle of stick-slip drive is as follows: under the action of a periodic asymmetric driving voltage (such as a sawtooth wave voltage), a large stroke motion with multiple superimposed steps is achieved through friction and inertia; under a smooth driving voltage (such as a sinusoidal driving voltage), the mover can achieve precise positioning motion with a smooth trajectory.

[0003] Although piezoelectric stick-slip microgrippers offer advantages such as high precision and large stroke, several problems remain. First, in stick-slip single-step displacement, the sharp decrease in driving voltage causes the mover to retract under dynamic friction, significantly reducing motion precision and stability. Second, the small single-step displacement not only limits the mover's speed but also restricts the precision range within that single step. While increasing the driving frequency can improve speed, it sacrifices system stability, exacerbates wear on the drive mechanism and mover, and causes severe overheating of the actuator. Increasing the single-step displacement not only improves speed and avoids the drawbacks of high-frequency drives but also expands the precision range. Third, piezoelectric stick-slip microgrippers typically lack a constant force mechanism, making the output force uncontrollable and prone to damaging the manipulated object, thus compromising the efficiency and quality of micro-operations.

[0004] In summary, existing piezoelectric stick-slip microgrippers have poor motion accuracy and stability, and lack constant force output. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output. This micro-clamping system offers advantages such as high precision, large single-step displacement, and suppression of stick-slip regression, exhibiting excellent motion stability.

[0006] A two-degree-of-freedom piezoelectric stick-slip micro-gripping system with constant force output includes a rotating stick-slip motion platform, a connector, and a stick-slip micro-gripper; the rotating stick-slip motion platform includes a base, a multi-directional compliant piezoelectric drive mechanism, and a rotating component;

[0007] The rotating component and the multi-directional compliant piezoelectric drive mechanism are mounted on the base, and the rotating component can rotate relative to the base;

[0008] The output end of the multi-directional compliant piezoelectric drive mechanism is in contact with the outer peripheral side of the rotating part;

[0009] The multi-directional compliant piezoelectric drive mechanism realizes a large stroke motion of the rotating part by multiple superimposed steps under the action of periodic drive voltage, and the multi-directional compliant piezoelectric drive mechanism realizes a precise positioning motion of the rotating part with a smooth trajectory under the action of smooth drive voltage.

[0010] The connector is mounted on the rotating part, and the stick-slip micro-gripper is mounted on the connector, which can realize the clamping operation with constant force output.

[0011] Furthermore, the multi-directional compliant piezoelectric drive mechanism includes a frame, a bridge lever composite amplification mechanism, a composite bridge amplification mechanism, a preload mechanism A, a preload mechanism B, a piezoelectric stack driver I, and a piezoelectric stack driver II;

[0012] The frame has a bridge lever compound amplification mechanism, a compound bridge amplification mechanism, a preload mechanism A, and a preload mechanism B;

[0013] The piezoelectric stack driver II is installed on the bridge lever composite amplification mechanism. After the piezoelectric stack driver II is powered on, the input displacement is amplified and output through the bridge lever composite amplification mechanism. The bridge lever composite amplification mechanism drives the rotating parts to rotate by friction.

[0014] The piezoelectric stacked actuator I is mounted on the composite bridge amplification mechanism. After the piezoelectric stacked actuator I is powered on, the displacement is amplified and output through the composite bridge amplification mechanism. The composite bridge amplification mechanism is used to suppress the retraction motion of the rotating part by friction. The preload mechanism A is connected to the bridge lever composite amplification mechanism and is used to adjust the distance between the bridge lever composite amplification mechanism and the rotating part and the initial positive pressure. The preload mechanism B is connected to the composite bridge amplification mechanism and is used to adjust the distance between the composite bridge amplification mechanism and the rotating part and the initial positive pressure.

[0015] Furthermore, the composite bridge amplification mechanism includes a bridge amplification mechanism B and a half-bridge amplification mechanism connected together, and the pre-tightening mechanism B is connected to the bridge amplification mechanism B and the frame respectively through flexible hinges.

[0016] The piezoelectric stack driver I is mounted on the bridge amplification mechanism B. After the piezoelectric stack driver I is powered on, the displacement is amplified through the bridge amplification mechanism B and the half-bridge amplification mechanism. The output end of the half-bridge amplification mechanism moves linearly to suppress the retraction of the rotating parts due to friction.

[0017] Furthermore, the stick-slip micro-gripper includes a mounting base, a half-bridge lever piezoelectric drive mechanism, a guide rail, slider one, slider two, a force-measuring clamping arm, and a constant-force clamping arm. The mounting base is mounted on the connector, the guide rail is mounted on the mounting base, slider one and slider two are slidably disposed on the guide rail, the force-measuring clamping arm is mounted on slider one, the constant-force clamping arm is mounted on slider two, and the half-bridge lever piezoelectric drive mechanism is mounted on the mounting base. When energized, the half-bridge lever piezoelectric drive mechanism amplifies the input displacement and outputs it, which is used to frictionally drive slider one and slider two to move closer or further apart, thereby realizing the clamping and release of the force-measuring clamping arm and the constant-force clamping arm. The half-bridge lever piezoelectric drive mechanism includes a half-bridge lever composite compliant mechanism and two piezoelectric stacked actuators III.

[0018] The advantages of this invention compared to the prior art are:

[0019] 1. The rotating stick-slip motion platform and stick-slip micro-gripper of this application are both piezoelectric stick-slip driven. Therefore, this invention has the advantages of two degrees of freedom, large stroke and high precision.

[0020] 2. The designed composite bridge amplification mechanism, bridge lever composite amplification mechanism, and half-bridge lever composite compliant mechanism all have three-stage amplification functions, enabling the present invention to have a large single-step displacement and a large precision operation range.

[0021] 3. For the rotating stick-slip motion platform, the proposed driving method to suppress stick-slip retraction motion suppresses the retraction motion and ensures the smoothness of motion and control accuracy.

[0022] 4. The stick-slip micro gripper is designed with a constant force gripping arm, which ensures constant force gripping of the micro-manipulated object, prevents damage and fall-off of the micro-manipulated object during operation, and improves work efficiency.

[0023] 5. The clamping system of this application is lightweight, easy to operate, and easy to integrate into micromanipulation robot systems and microelectromechanical systems.

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments: Attached Figure Description

[0025] Figure 1 This is the assembly drawing of the two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output of this application;

[0026] Figure 2 This is the assembly drawing of the rotating stick-slip motion platform;

[0027] Figure 3 A schematic diagram of a multi-directional compliant piezoelectric drive mechanism with a driver;

[0028] Figure 4 A schematic diagram of a multi-directional compliant piezoelectric drive mechanism with a flexible hinge;

[0029] Figure 5 Schematic diagram of the driving principle for suppressing stick-slip regression motion;

[0030] Figure 6 A schematic diagram of the base of the rotating stick-slip motion platform;

[0031] Figure 7 This is a schematic diagram of a precision rotating bearing;

[0032] Figure 8 This is the assembly drawing of the adhesive-slip micro gripper;

[0033] Figure 9 This is a schematic diagram of a half-bridge lever drive mechanism;

[0034] Figure 10 Schematic diagram of a semi-bridge lever compound compliant mechanism;

[0035] Figure 11 Schematic diagram of the micro gripper guide rail;

[0036] Figure 12 This is a schematic diagram of a force-measuring clamping arm;

[0037] Figure 13 This is a schematic diagram of a constant force clamping arm;

[0038] Figure 14 This is a schematic diagram showing the relationship between the clamping force and displacement of the constant force clamping arm;

[0039] Figure 15 Schematic diagram of the micro gripper base;

[0040] Figure 16 This is a schematic diagram of the connector. Detailed Implementation

[0041] The embodiments of the technical solutions of this application will now be described in detail with reference to the accompanying drawings. Unless otherwise stated, the technical or scientific terms used in this application have the ordinary meanings understood by those skilled in the art.

[0042] Example 1, such as Figure 1 As shown, a two-degree-of-freedom piezoelectric stick-slip micro-gripping system with constant force output includes a rotating stick-slip motion platform 1, a connector 2, and a stick-slip micro-gripper 3;

[0043] The rotating stick-slip motion platform 1 includes a base 129, a multi-directional compliant piezoelectric drive mechanism 10, and a rotating component 130;

[0044] Figure 2 For the assembly drawing of the rotating stick-slip motion platform 1, the multi-directional compliant piezoelectric drive mechanism 10 is mounted on the base 129 by screw L1, and the rotating component 130 can rotate relative to the base 129; the rotating component 130 is mounted on the base 129 by screw G2.

[0045] The rotating stick-slip motion platform 1 drives the stick-slip micro-gripper 3 through the connecting piece 2 to achieve large stroke and high precision rotation. The stick-slip micro-gripper 3 realizes macro-micro precision clamping motion and achieves constant force output under the action of the constant force mechanism.

[0046] Optionally, the rotating component 130 is a precision rotary bearing.

[0047] Example 2, as follows Figure 3 and 4 As shown, the multi-directional compliant piezoelectric drive mechanism 10 includes a frame 11, a bridge lever composite amplification mechanism 101, a composite bridge amplification mechanism 102, a preload mechanism A103, a preload mechanism B104, a piezoelectric stack driver ID11, and a piezoelectric stack driver IID12.

[0048] The frame 11 is a fixed base used to connect and support the multi-directional compliant piezoelectric drive mechanism 10. The frame 11 has a bridge lever composite amplification mechanism 101, a composite bridge amplification mechanism 102, a preload mechanism A103, and a preload mechanism B104.

[0049] The piezoelectric stack driver IID12 is installed on the bridge lever composite amplification mechanism 101. After the piezoelectric stack driver IID12 is powered on, it amplifies the input displacement through the bridge lever composite amplification mechanism 101 and outputs it. The bridge lever composite amplification mechanism 101 drives the rotating component 130 to rotate by friction.

[0050] The piezoelectric stack driver ID11 is mounted on the composite bridge amplifier mechanism 102. After the piezoelectric stack driver ID11 is powered on, the displacement is amplified and output through the composite bridge amplifier mechanism 102. The composite bridge amplifier mechanism 102 is used to suppress the retraction motion of the rotating part 130 by friction.

[0051] The pre-tightening mechanism A103 is connected to the bridge lever composite amplification mechanism 101 and is used to adjust the distance between the bridge lever composite amplification mechanism 101 and the rotating component 130 and the initial positive pressure. The pre-tightening mechanism B104 is connected to the composite bridge amplification mechanism 102 and is used to adjust the distance between the composite bridge amplification mechanism 102 and the rotating component 130 and the initial positive pressure.

[0052] The bridge lever composite amplification mechanism 101 includes a bridge amplification mechanism A1011, a lever mechanism 1012 and a parallelogram mechanism 1013 connected to each other, realizing three-stage amplification of displacement. The pre-tightening mechanism A103 is connected to the parallelogram mechanism 1013 and the frame 11 respectively through flexible hinges.

[0053] The piezoelectric stack driver DII12 is mounted on the bridge amplification mechanism A1011. After the piezoelectric stack driver DII12 is powered on, the input displacement is amplified through the bridge amplification mechanism A1011, the lever mechanism 1012 and the parallelogram mechanism 1013. The output end of the parallelogram mechanism 1013 moves in translation, which is used to drive the rotating part 130 to rotate by friction.

[0054] Optionally, the bridge amplification mechanism A1011 has a symmetrical structure, comprising an output block 110, two input blocks 12 arranged in mirror image, two rigid rods a16, two rigid rods b17, two rigid rods c18, and two rigid rods d19. The two ends of rigid rods a16 and b17 are respectively connected to the frame 11 and the input blocks 12 via a first circular flexible hinge C11 and a second circular flexible hinge C12. A piezoelectric stack driver IID12 connected to the two input blocks 12 is provided between them. The two ends of rigid rods c18 and d19 are respectively connected to the frame 11 and the output block 110 via a third circular flexible hinge C16 and a fourth circular flexible hinge C15.

[0055] Optionally, the lever mechanism 1012 includes a rigid rod e126, a rotating rod 127, and a rigid rod f128; the two ends of the rigid rod e126 are connected to the output block 110 and the rotating rod 127 respectively via flexible hinges; the two ends of the rotating rod 127 are connected to the frame 11 and the rigid rod f128 respectively via a fifth straight-circular flexible hinge C17; and the rigid rod f128 is connected to the parallelogram mechanism 1013 via a sixth straight-circular flexible hinge C18.

[0056] Optionally, the parallelogram mechanism 1013 includes rigid rod I119, rigid rod II120 and rigid rod III121;

[0057] Rigid rods II120 and III121 are arranged in parallel. One end of rigid rods II120 and III121 is connected to rigid rod I119 through the sixth straight circular flexible hinge C18, and the other end of rigid rods II120 and III121 is connected to pretensioning mechanism A through the sixth straight circular flexible hinge C18. Rigid rods I119, II120, III121 and pretensioning mechanism A103 form a parallelogram structure.

[0058] Optionally, refer to Figure 4 The pre-tensioning mechanism A103 includes a rigid block 122, a T-block 123, and a blade-shaped flexible hinge connecting them and the frame 11. The blade-shaped flexible hinge is divided into a first blade-shaped flexible hinge F11, a second blade-shaped flexible hinge F12, a third blade-shaped flexible hinge F17, a fourth blade-shaped flexible hinge F18, a fifth blade-shaped flexible hinge F19, and a sixth blade-shaped flexible hinge F20.

[0059] T-block 123, rigid rod I119, rigid rod II120, and rigid rod III121 together form a parallelogram structure. T-block 123 and rigid block 122 are separated by the aforementioned series of leaf-shaped flexible hinges and connected to the frame 11. A second preload screw Y12 is screwed onto the frame 11. The rigid block 122 and T-block 123 adjust the distance and initial positive pressure between the parallelogram mechanism 1013 and the rotating member 130 through the second preload screw Y12.

[0060] Example 3, Reference Figure 3 and Figure 4 The composite bridge amplification mechanism 102 includes a bridge amplification mechanism B1021 and a half-bridge amplification mechanism 1022 connected together, realizing three-stage amplification of displacement and used to suppress stick-slip retraction motion. The bridge amplification mechanism B1021 is connected to the half-bridge amplification mechanism 1022 through a rod 135. The pre-tightening mechanism B104 is connected to the bridge amplification mechanism B1021 and the frame 11 through a leaf-shaped flexible hinge and a straight round flexible hinge, respectively.

[0061] The piezoelectric stack driver ID11 is mounted on the bridge amplification mechanism B1021. After the piezoelectric stack driver ID11 is powered on, the displacement is amplified through the bridge amplification mechanism B1021 and the half-bridge amplification mechanism 1022. The output end of the half-bridge amplification mechanism 1022 moves linearly to suppress the retraction motion of the rotating part 130 due to friction.

[0062] Optionally, the bridge amplification mechanism B1021 includes an input block 13, two rigid rods 111 (each mirror-symmetrical), two rigid rods 112, two rigid rods 113, two rigid rods 114, and an output block 115. The two ends of the rigid rods 111 and 112 are connected to the preload mechanism B104 and the two output blocks 115 respectively via flexible hinges. The two ends of the rigid rods 113 and 114 are connected to the output block 115 and the input block 13 respectively via the seventh straight-circular flexible hinge C13 and the eighth straight-circular flexible hinge C14. The output block 115 is connected to the half-bridge amplification mechanism 1022 via a flexible hinge and rod 135. A piezoelectric stack driver ID11 connected to the preload mechanism B104 and the input block 13 is provided between the two.

[0063] Optionally, the half-bridge amplification mechanism 1022 includes an output block 118, two rotating rods 116 arranged in a mirror image, and two rigid rods 117 arranged in a mirror image. One end of the rotating rod 116 is connected to the pre-tensioning mechanism B104 via a straight-round flexible hinge, and the other end of the rotating rod 116 is connected to one end of the rigid rod 117 via a straight-round flexible hinge. The other end of the rigid rod 117 is connected to the output block 118 via a straight-round flexible hinge.

[0064] Optionally, refer to Figure 4 The pre-tightening mechanism B104 includes a T-block 15, a frame 11, and blade-shaped flexible hinges connecting them. The blade-shaped flexible hinges are divided into a seventh blade-shaped flexible hinge F13, an eighth blade-shaped flexible hinge F14, a ninth blade-shaped flexible hinge F15, and a tenth blade-shaped flexible hinge F16. The T-block 15 is connected to the frame 11 through the aforementioned series of blade-shaped flexible hinges. A first pre-tightening screw Y11 is screwed onto the frame 11. The T-block 15 adjusts the distance and initial positive pressure between the half-bridge amplification mechanism 1022 and the rotating component 130 through the first pre-tightening screw Y11.

[0065] In the above, all the straight-round flexible hinges have two semi-circular cuts on both sides and a very thin thickness in the middle, and transmit motion through rotational elastic deformation.

[0066] In the above, all the blade-shaped flexible hinges are thin metal sheets with high stiffness along the direction of the blade-shaped flexible hinge and low stiffness in the vertical direction, transmitting motion through elastic deformation.

[0067] The aforementioned bridge-lever composite amplification mechanism 101 and composite bridge amplification mechanism 102 utilize the inverse piezoelectric effect. Piezoelectric stack actuators IID12 and ID11 convert electrical energy into mechanical energy, which elongates and moves linearly when voltage is applied, with the elongation varying with the voltage. For the bridge-lever composite amplification mechanism 101, the bridge amplification mechanism A1011 amplifies the input displacement of the piezoelectric stack actuator D12 once. Then, the lever mechanism 1012 and parallelogram mechanism 1013 amplify the displacement again, driving the outer ring of the precision rotating bearing 130 to rotate via friction. Tightening the second preload screw Y12 allows adjustment of the distance and normal force between the parallelogram mechanism 1013 and the precision rotating bearing 130 via the preload mechanism A103.

[0068] The composite bridge amplification mechanism 102 amplifies the input displacement of the piezoelectric stack driver ID11 in three stages. The preload force between the output block 118 and the precision rotary bearing 130 is adjusted by the preload mechanism B104. Screw L1 secures the multi-directional compliant piezoelectric drive mechanism 10 to the base 129, and screw G1 secures the rotating stick-slip motion platform 1 to the work area. The precision rotary bearing 130... Figure 7 As shown, the inner ring of the bearing is mounted on the base 129 by screw 3G2, and the outer ring rotates under the action of friction. Figure 6 As shown, the middle portion of the base 129 is recessed, directly opposite the moving part of the multi-directional compliant piezoelectric drive mechanism 10. This recessed portion serves to prevent contact between the base 129 and the moving part of the multi-directional compliant piezoelectric drive mechanism 10, thus avoiding friction during movement. The base 129 consists of a first boss 133, a second boss 134, a first through hole 131, and a threaded hole 132. The multi-directional compliant drive mechanism 10 is fixed to the first boss 133 using screws such as L1 to prevent contact friction between the multi-directional compliant piezoelectric drive mechanism 10 and the base 129 during movement. Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the inner ring of the precision rotary bearing 130 is mounted on the second boss 134 of the base, and the outer ring contacts the half-bridge amplification mechanism 1022 and the parallelogram mechanism 1013; the connecting member 2 is as follows Figure 16 As shown, the lower surface is connected to the outer ring of the bearing, and the upper surface is connected to the adhesive-slip micro-clamp 3.

[0069] Example 4: This example describes the cutting process of the multi-directional compliant piezoelectric drive mechanism 10, such as... Figure 3 and Figure 4As shown, the moving parts of the multi-directional compliant piezoelectric drive mechanism 10 are machined by wire cutting, eliminating the need for assembly and avoiding assembly errors. Since the moving parts of the multi-directional compliant piezoelectric drive mechanism exhibit local symmetry and each part has the same processing technology, when describing the cutting slits, only the bridge lever composite amplification mechanism 101 needs to be used as an example. The area enclosed by the location of the precision rotating bearing 130 and the outer sides of the frame 11, preload mechanism B104, bridge lever composite amplification mechanism 101, and composite bridge amplification mechanism 102 constitutes the first cutting slit. The area where the piezoelectric stacked driver IID12 is located is the second cutting slit. The closed area enclosed by the input block 12, rigid rod a16, rigid rod b17, frame 11, and several straight-circular flexible hinges connecting them (such as the first straight-circular flexible hinge C11, the second straight-circular flexible hinge C12, etc.) constitutes the third cutting slit. The bridge amplification mechanism A1011 is fully symmetrical, and the other three cutting slits are the same as the third cutting slit described above. The closed area enclosed by the frame 11, the lower half of the bridge amplification mechanism A1011, and the lever mechanism 1012 constitutes the fourth cutting slit. The closed area enclosed by the lever mechanism 1012, the frame 11, the parallelogram mechanism 1013, and the pre-tensioning mechanism A103 constitutes the fifth cutting slit. The closed area enclosed by levers I119, II120, III121, T-block 123, and several straight-round flexible hinges connecting them constitutes the sixth cutting slit. The stick-slip clamping system of this embodiment uses flexible hinges and is processed into a single unit by wire cutting, which has the advantages of small size, no mechanical friction, high guiding accuracy, and no need for assembly.

[0070] Example 5, in conjunction with the following Figures 1-7 This section introduces the working principle of the multi-directional compliant piezoelectric drive mechanism 10.

[0071] Here Figure 2 and Figure 3 For example, the horizontal direction to the right is the positive x-axis, the horizontal upward direction perpendicular to the x-axis is the positive y-axis, and the vertical upward direction perpendicular to the horizontal plane is the positive z-axis.

[0072] like Figure 3 and Figure 4As shown, for the bridge-type lever composite amplification mechanism 101, the bridge amplification mechanism A1011 is a symmetrical mechanism. A voltage amplified by a power amplifier is applied to the piezoelectric stack driver IID12, causing the piezoelectric stack driver IID12 to extend and push the two upper and lower input blocks I12 to move. Through a linear-circular flexible hinge (such as the second linear-circular flexible hinge C12), the rigid rods a16 and b17 rotate clockwise around the flexible hinge (the first linear-circular flexible hinge C11, etc.). Through a linear-circular flexible hinge (such as the third linear-circular flexible hinge C16, etc.), the rigid rods c18 and d19 rotate counterclockwise around the linear-circular flexible hinge (the third linear-circular flexible hinge C16, etc.). The output block 110 is driven to move in the negative x-axis direction by a straight circular flexible hinge (such as the fourth straight circular flexible hinge C15), completing the first amplification of the input displacement. The output block 110 drives the rigid rod e126 and the rotating rod 127 to move through the straight circular flexible hinge connected to it. The rotating rod 127 rotates counterclockwise around the fifth straight circular flexible hinge C17, completing the second displacement amplification. The rotating rod 127 drives the rigid rod II120 to rotate counterclockwise through the rigid rod f128, completing the third displacement amplification. At this time, the output rod I119 of the parallelogram mechanism 1013 translates (including the x and y directions of the component motion), and the rigid rod I119 drives the outer ring of the precision rotating bearing to rotate through friction.

[0073] The composite bridge amplification mechanism 102 is a symmetrical mechanism. It applies a voltage amplified by a power amplifier to the piezoelectric stack driver ID11, causing ID11 to extend and push input block 13 to translate in the positive x-direction. This, through a circular flexible hinge (such as the eighth circular flexible hinge C14), drives rigid rods 113 and 114 to rotate counterclockwise around the circular flexible hinge (such as the eighth circular flexible hinge C14). This rotation is further facilitated by the seventh circular flexible hinge C... The first amplification of the input displacement is achieved by the translational motion of output block 115 driven by rod 135 and its connected circular flexible hinge. Then, output block 115 drives the upper rotating rod 116 to rotate clockwise via rod 135 and its connected circular flexible hinge, completing the second displacement amplification. The rotating rod 116 then drives the upper rigid rod IV 117 to move counterclockwise via its connected circular flexible hinge. The rigid rod IV 117, in turn, drives output block 118 to translate in the positive x-direction via its connected circular flexible hinge. Output block 118 increases the normal pressure between itself and the outer ring of the rotating bearing 130, thereby increasing braking friction and suppressing stick-slip retraction.

[0074] Figure 5 It is a driving method to suppress rotational stick-slip retraction motion. Figure 5 (a) represents the driving voltage and output displacement; Figure 5 (b) is the outer ring of the bearing. Figure 2A schematic diagram of z-axis rotation. Drivers D12 and D11 apply driving voltages U1 and U2 respectively, and the displacement motion is as follows: Figure 5 As shown in (a). During t0-t a During this stage, the rigid rod 119 of the parallelogram mechanism translates (including x- and y-axis component motions). The y-axis component motion increases the normal force between the rigid rod 119 and the outer ring of the precision bearing, thereby increasing the friction between them. Under the action of friction, the x-axis component motion drives the outer ring of the bearing to rotate clockwise. During this stage, the driving voltage U2 is 0, and the output displacement of the nested bridge composite amplification mechanism is 0. At t a -t b During the t1-t2 phase, U2 rapidly increases and remains constant, increasing the normal pressure between the output block 118 of the nested bridge-type composite amplifier mechanism and the outer ring of the precision rotating bearing 130. This also dramatically increases the friction between them, suppressing the bearing retraction caused by the rapid decrease in voltage U1 in the parallelogram mechanism 1013 during the t1-t2 phase. Without the composite bridge amplifier mechanism 102 and the applied driving voltage U2, during the t1-t2 phase, the driving voltage U1 would rapidly decrease, causing the parallelogram mechanism 1013 to return to its initial state under the action of elastic force. The output rod I119 would then cause the outer ring of the bearing to retract counterclockwise by a certain displacement due to sliding friction. It is precisely because of the composite bridge amplifier mechanism 102 and the applied driving voltage U2 that the stick-slip retraction motion is suppressed. Under the action of a periodic driving voltage, the rotating stick-slip motion platform 1 achieves a large-stroke motion with multiple superimposed steps. Under the action of a smooth driving voltage (such as a sinusoidal driving voltage), the rotating stick-slip motion platform 1 can achieve a precise positioning motion with a smooth trajectory.

[0075] Example 6: This example further describes the stick-slip microgripper 3, referring to... Figures 8-13 .

[0076] The stick-slip micro gripper 3 includes a mounting base 32, a half-bridge lever piezoelectric drive mechanism 31, a guide rail 33, a first slider 341, a second slider 342, a force-measuring gripping arm 351, and a constant force gripping arm 352.

[0077] Mounting base 32 is mounted on connector 2, guide rail 33 is mounted on mounting base 32, slider one 341 and slider two 342 are slidably mounted on guide rail 3, force measuring clamping arm 351 is mounted on slider one 341, and constant force clamping arm 352 is mounted on slider two 342.

[0078] The half-bridge lever piezoelectric drive mechanism 31 is mounted on the mounting base 32. When the half-bridge lever piezoelectric drive mechanism 31 is energized, it amplifies the input displacement and outputs it to drive the first slider 341 and the second slider 342 to move closer or further apart, thereby realizing the clamping and releasing operations of the force measuring clamping arm 351 and the constant force clamping arm 352.

[0079] The semi-bridge lever piezoelectric drive mechanism 31 includes a semi-bridge lever composite compliant mechanism and two piezoelectric stacked drivers IIID21;

[0080] The semi-bridge lever composite compliant mechanism has a symmetrical structure, which includes a bracket 3101, two levers 3102, two semi-bridge mechanisms 3103 and two pre-tensioning mechanisms C312; the two semi-bridge mechanisms 3103 and the two pre-tensioning mechanisms C312 are connected to the bracket 3101.

[0081] Furthermore, refer to Figures 9-10 The half-bridge mechanism 3103 has a symmetrical structure. Each half-bridge mechanism 3103 includes a first rigid rod 3104, a second rigid rod 3105, an output block 3106, a third rigid rod 3107, a fourth rigid rod 3108, a fifth rigid rod 3109, a rotating rod 3113, a rotating rod 3114, a rotating rod 3115, a rotating rod 3116, an upper translational block 3111, a lower translational block 3112, a frame 3101, and several flexible hinges. The two ends of the first rigid rod 3104 and the second rigid rod 3105 are connected to the upper translational block 3111 and the output block 3106 respectively via flexible hinges. The two ends of the fourth rigid rod 3108 and the fifth rigid rod 3109 are connected to the lower translational block 3112 and the output block 3106 respectively via flexible hinges. The rotating rod 3107, the second rigid rod 3105, the third rigid rod 3106, the fourth rigid rod 3107, the fifth rigid rod 3108, the fifth rigid rod 3109, the third rigid rod 3109, the fourth rigid rod 3109, the fifth rigid rod 3109, the sixth rigid rod 3106, the seventh rigid rod 3107, the thief 3108, the thief 3109, the thief 3106, the thief 3109, the thief 3106, the thief 3107, the thief 3108 ...9 3113 is connected to rotating rod four 3114 via a flexible hinge, rotating rod five 3115 is connected to rotating rod six 3116 via a flexible hinge, a piezoelectric stacked actuator IIID21 connected to rotating rod four 3114 and rotating rod six 3116 is provided between them, upper translation block 3111 is flexibly connected to rotating rod three 3113 and rotating rod four 3114 respectively, lower translation block 3112 is flexibly connected to rotating rod five 3115 and rotating rod six 3116 respectively, output block four 3106 is flexibly connected to third rigid rod 3107, third rigid rod 3107 is flexibly connected to lever 3102, each pre-tensioning mechanism C312 is connected to lever 3102 via a flexible hinge, used to adjust the distance and initial pre-tensioning force between lever 3102 and slider one 341 and slider two 342 respectively.

[0082] The flexible hinges mentioned above are all straight-round flexible hinges, specifically defined as: Straight-round flexible hinge one C21, Straight-round flexible hinge two C22, Straight-round flexible hinge three C23, Straight-round flexible hinge four C24, Straight-round flexible hinge five C25, Straight-round flexible hinge six C26, Straight-round flexible hinge seven C27, and Straight-round flexible hinge eight C28.

[0083] Furthermore, participants Figure 10The pre-tensioning mechanism C312 has a symmetrical structure. Each pre-tensioning mechanism C312 includes a sixth rigid rod 3121, a seventh rigid rod 3122, and several flexible hinges. The sixth rigid rod 3121 is connected to the seventh rigid rod 3122 through a leaf-shaped flexible hinge. The sixth rigid rod 3121 and the seventh rigid rod 3122 are respectively connected to the bracket 3101 through leaf-shaped flexible hinges. The sixth rigid rod 3121 is connected to the lever 3102 through a straight-round flexible hinge. The pre-tensioning mechanism C312 is used to adjust the distance between the lever 3102 and the slider and the initial pre-tensioning force.

[0084] The aforementioned blade-shaped flexible hinges are defined as blade-shaped flexible hinge one F21, blade-shaped flexible hinge two F22, blade-shaped flexible hinge three F23, blade-shaped flexible hinge four F24, blade-shaped flexible hinge five F25, blade-shaped flexible hinge six F26, blade-shaped flexible hinge seven F27, blade-shaped flexible hinge eight F28, and blade-shaped flexible hinge nine F29.

[0085] The leaf-shaped flexible hinge is an extremely thin metal sheet. The distance between lever 3102 and slider 341 and the initial preload are adjusted by turning the third preload screw located in the preload threaded hole W61. Utilizing the inverse piezoelectric effect, the two piezoelectric stacked actuators IIID21 extend when voltage is applied. The half-bridge mechanism 3103 amplifies the input displacement of the piezoelectric stacked actuators IIID21 twice. The two levers 3102 further amplify the displacement. The frictional force drives slider 341 and slider 342 to move, which in turn drives their corresponding force-measuring clamping arms 351 and constant-force clamping arms 352 to perform object clamping operations.

[0086] Example 7: The following describes the processing method of the semi-bridge lever composite compliant mechanism, such as... Figure 9 and Figure 10 As shown, the processing method of the semi-bridge lever composite compliant mechanism is the same as that of the multi-directional compliant piezoelectric drive mechanism 10, both of which are processed by wire cutting, which will not be described in detail here.

[0087] like Figure 9 , Figure 11As shown, the half-bridge lever drive mechanism has a symmetrical structure, requiring only motion analysis of the left half. Applying a voltage amplified by a power amplifier to the piezoelectric stack actuator IIID21 causes it to extend, pushing rotating rod four 3114 clockwise and rotating rod six 3116 counterclockwise. This, via flexible hinges, drives the upper translation block 3111 and the lower translation block 3112 to translate, completing the first amplification of the input displacement. The upper and lower translation blocks 3111 and 3112 then drive four rigid rods (first rigid rod 3104, second rigid rod 3105, fourth rigid rod 3108, and fifth rigid rod 3109) to rotate via flexible hinges. The first and second rigid rods... 3105 rotates counterclockwise, while the fourth rigid rod 3108 and the fifth rigid rod 3109 rotate clockwise. This, in turn, drives the output block 3106 to move in the positive x-axis direction via a flexible hinge, completing the second amplification of the input displacement. The output block 3106, through a flexible hinge and the third rigid rod 3107, drives the connected lever 3102 to rotate clockwise, completing the third amplification of the input displacement. The output displacement of lever 3102 includes x-axis and y-axis components. The y-axis component increases the friction between lever 3102 and slider 341, while the x-axis component, under the influence of friction, drives slider 341 to move. A clamping arm is mounted on the slider, thus enabling the clamping operation.

[0088] Example 8, as Figure 11 As shown, the guide rail includes slider 341 and slider 342. The guide rail 33 has a through hole, and the slider has a threaded hole; as Figure 8 As shown, the guide rail 33 is fixed to the mounting base 32 by screws, and the slider 1 341 and slider 2 342 are respectively connected to the force measuring clamping arm 351 and the constant force clamping arm 352 by screws.

[0089] like Figure 12 As shown, the force-measuring clamping arm 351 is mainly composed of a first force-measuring rigid rod 3512, a second force-measuring rigid rod 3513, a third force-measuring rigid rod 3514, a clamp 3517, a first force-measuring beam 3515, and a second force-measuring beam 3516 connected in sequence. The first force-measuring beam 3515 and the second force-measuring beam 3516 are arranged in parallel at intervals. The third force-measuring rigid rod 3514, the clamp 3517, the first force-measuring beam 3515, and the second force-measuring beam 3516 form a hollow cavity. Force-measuring rigid rod 1 (3512) and force-measuring rigid rod 2 (3513) are vertically connected; force-measuring rigid rod 2 (3513) and force-measuring rigid rod 3 (3514) are vertically connected; force-measuring rigid rod 1 (3512) and force-measuring rigid rod 3 (3514) are arranged horizontally parallel; force-measuring rigid rod 2 (3513), force-measuring beam 1 (3515), and force-measuring beam 2 (3516) are arranged vertically parallel; strain gauge 3511 is attached to force-measuring beam 1 (3515). The output voltage U of strain gauge 3511... F=KF, where F is the clamping force and K is the proportionality coefficient; the proportionality coefficient K needs to be calibrated before use. Specifically, the clamping force F0 at the end of the force-measuring clamping arm 351 is first measured using a force sensor, and the output voltage U of the force-measuring strain gauge 3511 at this time is obtained. F Thus, we can obtain K = U F / F0.

[0090] like Figure 13 As shown, the constant force clamping arm 352 mainly consists of a constant force rigid rod 3522, a constant force rigid rod 3523, a constant force rigid rod 3524, a negative stiffness beam 3525, a negative stiffness beam 3526, a positive stiffness beam 3527, and a clamping rod 3521 connected together. The constant force rigid rod 3523 and the constant force rigid rod 3524 are vertically connected. Between the constant force rigid rod 3522 and the clamping rod 3521, there are negative stiffness beams 3525, 3526, and 3527 connected to them. There are one pair of each of the negative stiffness beams 3525, 3526, and 3527, and they are arranged in a mirror image of each other.

[0091] The vertical section of clamping rod 3521 is arranged perpendicularly and parallel to constant force rigid beam 3523.

[0092] The relationship between the clamping force and displacement of the constant force clamping arm 352 is as follows: Figure 14 As shown, the clamping force F first increases with the clamping displacement d g The force increases, and then the clamping operation is completed in the constant force zone (d1-d2).

[0093] like Figure 15 As shown, the mounting base 32 has a boss 328, a boss 329, a threaded hole 321, a threaded hole 322, a threaded hole 323, a threaded hole 324, a threaded hole 325, a threaded hole 326, and a second through hole 327; (Refer to...) Figure 11 and Figure 15 The guide rail 33 is mounted to the boss 328 of the mounting base 32 by screws screwed into threaded holes 321, 322, and 323; as shown Figure 16 As shown, the connector 2 is provided with a first threaded hole 237 and a mounting hole 236; the mounting base 32 and the connector 2 are connected together by a screw that passes through the second through hole 327 and is screwed into the first threaded hole 237; the connector 2 and the precision rotating shaft 130 are connected together by a screw that passes through the mounting hole 236 and is screwed into the threaded hole on the outer ring of the precision rotating bearing 130.

[0094] Reference Figure 8 , Figure 9 , Figure 15 and Figure 16To enhance the stability of the bracket 3101, a third through hole and a fourth through hole are provided at both ends of the bracket 3101. The bracket 3101 is connected to the boss 329 of the mounting base 32 by screws passing through the third and fourth through holes and screwed into threaded holes 325 and 326. A fifth through hole is also provided on the bracket 3101. The bracket 3101, the mounting base 32, and the connector 2 are connected together by screws passing through the fifth through hole and the second through hole 327 and screwed into the first threaded hole 237.

[0095] The large-stroke motion of the stick-slip microgripper 3 is also achieved through stick-slip drive. The half-bridge lever drive mechanism 31 has a symmetrical structure, so only the left half needs to be described when introducing the stick-slip motion; applying force to the piezoelectric stack actuator IIID21 Figure 5 The periodic sawtooth voltage U1 in the force-measuring clamping arm 351 enables multi-step superimposed large-stroke motion under the action of friction and inertia. Under the action of a smooth driving voltage (such as a sinusoidal driving voltage), the clamping arm can achieve precise positioning motion with a smooth trajectory. Under the action of the periodic sawtooth voltage U1, the stick-slip micro-gripper 3 realizes the clamping and release of objects of different sizes. After clamping the object, the stick-slip micro-gripper 3 performs precise clamping operation under the action of a smooth driving voltage (such as a sinusoidal driving voltage), and achieves constant force output under the action of the constant force clamping arm 352.

[0096] This application has been disclosed above with preferred embodiments, but it is not intended to limit this application. Any person skilled in the art can make some changes or modifications to the above-disclosed structure and technical content to create equivalent embodiments without departing from the scope of the technical solution of this application, and all such modifications and modifications are within the scope of the technical solution of this application.

Claims

1. A two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output, characterized in that: It includes a rotating stick-slip motion platform (1), a connector (2), and a stick-slip micro-gripper (3); The rotating stick-slip motion platform (1) includes a base (129), a multi-directional compliant piezoelectric drive mechanism (10), and a rotating component (130). The rotating component (130) and the multi-directional compliant piezoelectric drive mechanism (10) are mounted on the base (129), and the rotating component (130) can rotate relative to the base (129); The output end of the multi-directional compliant piezoelectric drive mechanism (10) is in contact with the outer peripheral side of the rotating part (130); The multi-directional compliant piezoelectric drive mechanism (10) realizes the large stroke motion of the rotating part (130) by multiple superimposed steps under the action of periodic drive voltage, and the multi-directional compliant piezoelectric drive mechanism (10) realizes the precise positioning motion of the rotating part (130) on a smooth trajectory under the action of smooth drive voltage. The connector (2) is installed on the rotating part (130), and the stick-slip micro gripper (3) is installed on the connector (2), which can realize the clamping operation with constant force output.

2. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 1, characterized in that: The multi-directional compliant piezoelectric drive mechanism (10) includes a frame (11), a bridge lever composite amplification mechanism (101), a composite bridge amplification mechanism (102), a preload mechanism A (103), a preload mechanism B (104), a piezoelectric stack driver I (D11), and a piezoelectric stack driver II (D12). The frame (11) has a bridge lever compound amplification mechanism (101), a compound bridge amplification mechanism (102), a pretensioning mechanism A (103) and a pretensioning mechanism B (104). The piezoelectric stack driver II (D12) is installed on the bridge lever composite amplifier mechanism (101). After the piezoelectric stack driver II (D12) is powered on, the input displacement is amplified and output through the bridge lever composite amplifier mechanism (101). The bridge lever composite amplifier mechanism (101) drives the rotating part (130) to rotate by friction. The piezoelectric stack driver I (D11) is mounted on the composite bridge amplifier mechanism (102). After the piezoelectric stack driver I (D11) is powered on, the displacement is amplified and output through the composite bridge amplifier mechanism (102). The composite bridge amplifier mechanism (102) is used to suppress the retraction motion of the rotating part (130) by friction. The pre-tightening mechanism A (103) is connected to the bridge lever composite amplification mechanism (101) and is used to adjust the distance between the bridge lever composite amplification mechanism (101) and the rotating part (130) and the initial positive pressure. The pre-tightening mechanism B (104) is connected to the composite bridge amplification mechanism (102) and is used to adjust the distance between the composite bridge amplification mechanism (102) and the rotating part (130) and the initial positive pressure.

3. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 2, characterized in that: The bridge lever composite amplification mechanism (101) includes a bridge amplification mechanism A (1011), a lever mechanism (1012), and a parallelogram mechanism (1013) connected together. The pre-tightening mechanism A (103) is connected to the parallelogram mechanism (1013) and the frame (11) respectively through flexible hinges. The piezoelectric stack driver II (D12) is mounted on the bridge amplification mechanism A (1011). After the piezoelectric stack driver II (D12) is powered on, the input displacement is amplified through the bridge amplification mechanism A (1011), the lever mechanism (1012) and the parallelogram mechanism (1013). The output end of the parallelogram mechanism (1013) moves in translation, which is used to drive the rotating part (130) to rotate by friction.

4. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 3, characterized in that: The bridge amplification mechanism A (1011) includes an output block 1 (110), two input blocks 1 (12) arranged in mirror, two rigid rods a (16), two rigid rods b (17), two rigid rods c (18) and two rigid rods d (19); the two ends of the rigid rods a (16) and b (17) are connected to the frame (11) and the input blocks 1 (12) respectively by flexible hinges, and a piezoelectric stack driver II (D12) is provided between the two input blocks 1 (12) and connected to them. The two ends of the rigid rods c (18) and d (19) are connected to the frame (11) and the output block 1 (110) respectively by flexible hinges.

5. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 3, characterized in that: The lever mechanism (1012) includes a rigid rod e (126), a rotating rod a (127), and a rigid rod f (128). The two ends of the rigid rod e (126) are connected to the output block (110) and the rotating rod one (127) respectively through flexible hinges. The two ends of the rotating rod one (127) are connected to the frame (11) and the rigid rod f (128) respectively through flexible hinges. The rigid rod f (128) is connected to the parallelogram mechanism (1013) through flexible hinges.

6. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 5, characterized in that: The parallelogram mechanism (1013) includes rigid rod I (119), rigid rod II (120) and rigid rod III (121). Rigid rods II (120) and III (121) are arranged in parallel. One end of rigid rods II (120) and III (121) is connected to rigid rod I (119) via a flexible hinge. The other end of rigid rods II (120) and III (121) is connected to pretensioning mechanism (A) via a flexible hinge. Rigid rod I (119), rigid rod II (120), rigid rod III (121) and pretensioning mechanism A (103) form a parallelogram structure.

7. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 2, characterized in that: The composite bridge amplification mechanism (102) includes a bridge amplification mechanism B (1021) and a half-bridge amplification mechanism (1022) connected together. The pre-tightening mechanism B (104) is connected to the bridge amplification mechanism B (1021) and the frame (11) respectively through flexible hinges. The piezoelectric stack driver I (D11) is mounted on the bridge amplifier mechanism B (1021). After the piezoelectric stack driver I (D11) is powered on, the displacement is amplified through the bridge amplifier mechanism B (1021) and the half-bridge amplifier mechanism (1022). The output end of the half-bridge amplifier mechanism (1022) moves linearly to suppress the retraction motion of the rotating part (130) due to friction.

8. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 7, characterized in that: The bridge amplifier mechanism B (1021) includes an input block two (13), two rigid rods one (111), two rigid rods two (112), two rigid rods three (113), two rigid rods four (114), and an output block two (115). The two ends of the rigid rods one (111) and two rigid rods two (112) are connected to the preload mechanism B (104) and the two output blocks (115) respectively by flexible hinges. The two ends of the rigid rods three (113) and four rigid rods four (114) are connected to the output block two (115) and the input block two (13) respectively by flexible hinges. The output block two (115) is connected to the half-bridge amplifier mechanism (1022) by flexible hinges. A piezoelectric stack driver I (D11) is provided between the preload mechanism B (104) and the input block two (13) and connected to both. The half-bridge amplification mechanism (1022) includes an output block three (118), two rotating rods two (116) arranged in a mirror image, and two rigid rods four (117) arranged in a mirror image. One end of the rotating rod two (116) is connected to the pre-tensioning mechanism B (104) via a flexible hinge, and the other end of the rotating rod two (116) is connected to one end of the rigid rod four (117) via a flexible hinge. The other end of the rigid rod four (117) is connected to the output block three (118) via a flexible hinge.

9. The two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 1, characterized in that: The stick-slip micro gripper (3) includes a mounting base (32), a half-bridge lever piezoelectric drive mechanism (31), a guide rail (33), a slider one (341), a slider two (342), a force measuring gripping arm (351), and a constant force gripping arm (352). Mounting base (32) is mounted on connector (2), guide rail (33) is mounted on mounting base (32), slider one (341) and slider two (342) are slidably set on guide rail (3), force measuring clamping arm (351) is mounted on slider one (341), constant force clamping arm (352) is mounted on slider two (342); half-bridge lever piezoelectric drive mechanism (31) is mounted on mounting base (32). When the half-bridge lever piezoelectric drive mechanism (31) is energized, it amplifies the input displacement and outputs it to drive slider one (341) and slider two (342) to move closer or further away from each other through friction, so as to realize the clamping and release of force measuring clamping arm (351) and constant force clamping arm (352).

10. A two-degree-of-freedom piezoelectric stick-slip micro-clamping system with constant force output according to claim 9, characterized in that: The half-bridge lever piezoelectric drive mechanism (31) includes a half-bridge lever composite compliant mechanism and two piezoelectric stacked actuators III (D21). The semi-bridge lever composite compliant mechanism includes a bracket (3101), two levers (3102), two semi-bridge mechanisms (3103), and two pre-tensioning mechanisms C (312); the two semi-bridge mechanisms (3103) and the two pre-tensioning mechanisms C (312) are mounted on the bracket (3101). Each half-bridge mechanism (3103) includes a first rigid rod (3104), a second rigid rod (3105), an output block four (3106), a third rigid rod (3107), a fourth rigid rod (3108), a fifth rigid rod (3109), a rotating rod three (3113), a rotating rod four (3114), a rotating rod five (3115), a rotating rod six (3116), an upper translational block (3111), a lower translational block (3112), a frame (3101), and several flexible hinges; the two ends of the first rigid rod (3104) and the second rigid rod (3105) are connected to the upper translational block (3111) and the output block four (3106) respectively via flexible hinges, the two ends of the fourth rigid rod (3108) and the fifth rigid rod (3109) are connected to the lower translational block (3112) and the output block four (3106) respectively via flexible hinges, and the rotating rod three... (3113) is connected to the fourth rotating rod (3114) via a flexible hinge. The fifth rotating rod (3115) is connected to the sixth rotating rod (3116) via a flexible hinge. A piezoelectric stacked actuator III (D21) is provided between the fourth rotating rod (3114) and the sixth rotating rod (3116) and connected to them. The upper translation block (3111) is flexibly connected to the third rotating rod (3113) and the fourth rotating rod (3114) respectively. The lower translation block (3112) is flexibly connected to the fifth rotating rod (3115) and the sixth rotating rod (3116) respectively. The output block four (3106) is flexibly connected to the third rigid rod (3107). The third rigid rod (3107) is flexibly connected to the lever (3102). Each pre-tightening mechanism C (312) is connected to the lever (3102) via a flexible hinge and is used to adjust the distance between the lever (3102) and the slider and the initial pre-tightening force.

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