Torsion actuating piezoelectric stick-slip driving system and driving method thereof

Abstract

The invention discloses a torsion actuating piezoelectric stick-slip driving system and a driving method thereof, and relates to the technical field of piezoelectric ceramic driving. A platform top cover is installed on the surface of the platform base in a sliding mode, the piezoelectric flexible hinge driver is composed of a torsion driving type flexible mechanism and two piezoelectric ceramics, and the torsion driving type flexible mechanism comprises a hinge top plate, a hinge base, a middle supporting arm and two side supporting arms, a hinge top plate is provided with a semi-cylindrical driving foot which is in contact with a platform top cover, a hinge base and a platform base are installed and fixed, a middle supporting arm is provided with a bottom torsion hinge and a top torsion hinge, a side supporting arm is provided with four bridge type hinges, and two piezoelectric ceramics are installed in two cavities of a torsion driving type flexible mechanism. Through the design of the torsion driving type flexible mechanism and the precise matching of piezoelectric ceramics, the effective combination of high speed and high precision is realized, the size of the driver is obviously reduced, the miniaturization of equipment is realized, and the improvement of the integration level and the operation flexibility of the equipment is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of piezoelectric ceramic drive, in particular to a torsionally actuated piezoelectric stick-slip drive system and a drive method thereof. Background Art

[0002] Conventional piezoelectric ceramic drives are mainly divided into three forms: inchworm form, ultrasonic motor form and stick-slip drive form. Among them, although the inchworm form has obvious advantages in small size and low energy consumption, it is limited by the difficulty in balancing power output and resolution. The ultrasonic motor form performs well in high torque and fast response, but is insufficient in high-precision control. The stick-slip drive form can overcome the shortcomings of both the inchworm form and the ultrasonic motor form, and has the advantages of high speed and high precision. It is widely used in the fields of precision positioning and micro-mechanical devices.

[0003] The high precision of stick-slip drive comes from the precise coordination between piezoelectric ceramics and flexible transmission mechanism. The development of piezoelectric ceramics has reached a technical bottleneck to a certain extent at this stage. Therefore, optimizing and improving the flexible transmission mechanism has become the main direction of the development of stick-slip drive. The present invention innovatively designs a torsional actuation stick-slip drive system, which effectively reduces its size while ensuring high speed and high mechanical resolution, thus realizing the miniaturization design of the stick-slip drive system. Summary of the invention

[0004] In order to address the shortcomings of the background technology, the present invention provides a torsional actuated piezoelectric stick-slip drive system and a driving method thereof, which achieves an effective combination of high speed and high precision through a unique torsional drive flexible mechanism design and precise matching of piezoelectric ceramics, can significantly reduce the size of the driver, realize miniaturization of the equipment, and help improve the integration and operational flexibility of the equipment.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A torsionally actuated piezoelectric stick-slip drive system comprises a piezoelectric flexible hinge driver, a platform base, a platform top cover and two cross roller guides, the platform top cover is slidably mounted on the surface of the platform base through the two cross roller guides arranged in parallel, the piezoelectric flexible hinge driver consists of a torsionally driven flexible mechanism and two piezoelectric ceramics, the torsionally driven flexible mechanism is an integrated structure, comprising a hinge top plate and a hinge base, and an intermediate support arm and two side support arms for connecting the two, a semi-cylindrical driving foot is integrally arranged at the middle position of the top end of the hinge top plate and is arranged in contact with the side of the platform top cover, two through holes are arranged on both sides of the hinge base and are fixed by two holes The bolts and nuts are installed and fixed to the platform base, and a bottom torsion hinge and a top torsion hinge are respectively arranged at the connection points of the middle support arm with the hinge base and the hinge top plate. The two side support arms are sequentially provided with four bridge hinges from the connection point of the hinge base to the connection point of the hinge top plate to divide the two side support arms into three-section structures, wherein the first and last bridge hinges are used as connection points and are arranged at the outer edges of the two side support arms, and the middle two bridge hinges are arranged at the inner edges of the two side support arms. The two piezoelectric ceramics are respectively installed in two cavities between the middle support arm and the two side support arms of the torsion-driven flexible mechanism, and are supported between the hinge top plate and the hinge base.

[0007] Furthermore, a grating ruler is fixed on the bottom surface of the platform top cover, and a reading head is fixed at a corresponding position on the surface of the platform base, and the movement of the platform top cover can be measured by the cooperation between the reading head and the grating ruler.

[0008] Furthermore, two long holes are processed in the platform base at positions corresponding to the two fixing bolts along the vertical direction of the platform top cover.

[0009] Furthermore, two fine-tuning threaded holes are integrally arranged on the side edge of the platform base, and the two fine-tuning threaded holes are arranged correspondingly to the two sides of the bottom end of the hinge base. Two fine-tuning bolts are screwed into the two fine-tuning threaded holes to support and limit the two sides of the bottom end of the hinge base, and the two fine-tuning bolts are respectively equipped with two locking nuts.

[0010] Furthermore, two pre-tightened hinges are arranged at the top of the hinge base and at the supporting points corresponding to the two piezoelectric ceramics.

[0011] Furthermore, two pre-tightening threaded holes are machined along the axes of the two piezoelectric ceramics at the bottom end of the hinge base, and two pre-tightening bolts are screwed into the two pre-tightening threaded holes to contact the corresponding pre-tightening hinges to cause them to deform and pre-tighten the piezoelectric ceramics relative to the torsion-driven flexible mechanism. The two pre-tightening bolts are respectively equipped with locking nuts.

[0012] A driving method of a torsionally actuated piezoelectric stick-slip driving system comprises the following steps:

[0013] During the actual driving period, only one side of the piezoelectric flexible hinge driver's piezoelectric ceramics expands and contracts at the same time. The piezoelectric ceramics are powered on according to the moving direction of the platform cover, and a sawtooth wave periodic voltage signal is applied to the piezoelectric ceramics. The voltage is divided into two stages: rising and falling in one cycle.

[0014] During the voltage rising stage, the piezoelectric ceramic on the powered side stretches, causing the hinge top plate to deflect, and the semi-cylindrical driving foot drives the platform top cover to move under the static friction force;

[0015] During the voltage drop phase, the piezoelectric ceramic on the powered side is shortened, and the deflected hinge top plate recovers its initial shape under the stress of the torsion-driven flexible mechanism. Due to the sliding friction and inertia, the platform top cover does not follow the semi-cylindrical driving foot back to its original position.

[0016] By repeating the periodic voltage rise and fall stages in this way, the piezoelectric flexible hinge driver controls the platform top cover to perform periodic stepping displacement output.

[0017] Furthermore, within one cycle of the sawtooth wave periodic voltage signal, the duration of the voltage drop phase is shorter than the duration of the voltage rise phase.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. Combination of high speed and high precision: The stick-slip drive technology successfully solves the shortcomings of the traditional inchworm form and ultrasonic motor form in power output, resolution and high-precision control, and realizes the effective combination of high speed and high precision, which is more suitable for precision positioning and micro-mechanical devices;

[0020] 2. Precise mechanical matching: The high precision of the stick-slip drive is due to the precise matching of piezoelectric ceramics and torsion-driven flexible mechanisms, which can provide better driving effects;

[0021] 3. Miniaturization design: The torsion-actuated piezoelectric flexible hinge drive can significantly reduce the size of the drive while maintaining high speed and high mechanical resolution, thus miniaturizing the device, improving the device's integration and operational flexibility, and broadening its application in high-tech fields.

[0022] 4. Novelty and practicality: Through the unique torsion-driven flexible mechanism design and the use of piezoelectric ceramics, it not only solves the limitations of existing technologies, but also achieves technological improvements with practical value, expanding the application potential and methods of stick-slip drive technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is an overall structural diagram of the torsion-actuated piezoelectric stick-slip drive system of the present invention;

[0024] Figure 2 is an exploded view of the torsionally actuated piezoelectric stick-slip drive system of the present invention;

[0025] Figure 3 is a structural diagram of the torsion-driven flexible mechanism of the present invention;

[0026] Figure 4 It is a structural diagram of the platform base in the present invention;

[0027] Figure 5 It is a schematic diagram of a sawtooth wave periodic voltage signal of a piezoelectric flexible hinge driver in the present invention;

[0028] Figure 6 1 is an application structure diagram of the torsionally actuated piezoelectric stick-slip drive system of the present invention in an embodiment.

[0029] In the figure: 1. Piezoelectric flexible hinge driver; 2. Platform base; 3. Cross roller guide; 4. Platform top cover; 5. Mounting plate; 6. Reading head; 7. Grating ruler; 8. Controller; 1-1. Torsion-driven flexible mechanism; 1-2. Piezoelectric ceramics; 1-3. Pre-tightening bolt; 1-4. Locking nut 1; 1-5. Fixing bolt; 2-1. Long hole; 2-2. Fine-tuning threaded hole; 2-3. Fine-tuning bolt; 2-4. Locking nut 2; 1-1-1. Semi-cylindrical Driving foot; 1-1-2, hinge top plate; 1-1-3, upper connecting block; 1-1-4, middle connecting block; 1-1-5, lower connecting block; 1-1-6, perforation; 1-1-7, pre-tightening threaded hole; 1-1-8, bottom torsion hinge; 1-1-9, pre-tightening hinge; 1-1-10, bridge hinge one; 1-1-11, bridge hinge two; 1-1-12, bridge hinge three; 1-1-13, bridge hinge four; 1-1-14, top torsion hinge. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] like Figure 1 to Figure 4 As shown, a torsionally actuated piezoelectric stick-slip drive system includes a piezoelectric flexible hinge driver 1, a platform base 2, a cross roller guide 3, a platform top cover 4, a mounting plate 5, a reading head 6 and a grating scale 7.

[0032] Overall platform assembly, combined Figure 1-2As shown, the platform base 2 is fixed on the work surface by screws in combination with the holes set around it, and two cross roller guides 3 are placed side by side on the surface of the platform base 2. The fixed track parts of the two cross roller guides 3 are connected and fixed to the platform base 2 by screws. The platform top cover 4 is installed on the two cross roller guides 3, and connected and fixed to the sliding track parts of the two cross roller guides 3 by screws, so that the platform base 2 and the platform top cover 4 are combined. The two track parts and the balls of the cross roller guides 3 are fully matched, and the preload force is adjusted so that the cross roller guides 3 can run smoothly within its stroke. In addition, the piezoelectric flexible hinge driver 1 is installed on the side of the platform top cover 4 on the platform base 2 to drive the platform top cover 4 to move along the sliding direction of the two cross roller guides 3. In order to facilitate accurate feedback of the moving distance of the platform top cover 4, a fixed grating ruler 7 is pasted on the bottom surface of the platform top cover 4, and a reading head 6 is fixed at a corresponding position on the surface of the platform base 2 through a mounting plate 5. The cooperation between the reading head 6 and the grating ruler 7 can achieve high-precision measurement of the movement of the platform top cover 4.

[0033] Hinge mechanism assembly, combined Figure 2-Figure 3As shown, the piezoelectric flexible hinge driver 1 consists of a torsion-driven flexible mechanism 1-1 and two piezoelectric ceramics 1-2. The torsion-driven flexible mechanism 1-1 is an integrated structure, including a hinge top plate 1-1-2 and a hinge base, as well as an intermediate support arm and two side support arms for connecting the two. A semi-cylindrical driving foot 1-1-1 is integrally arranged at the middle position of the top of the hinge top plate 1-1-2, which is arranged in contact with the side of the platform top cover 4. Two through holes 1-1-6 are arranged on both sides of the hinge base, and the torsion-driven flexible mechanism 1-1 is installed and fixed to the platform base 2 by two fixing bolts 1-5 combined with nuts. The middle position of the bottom end of the hinge top plate 1-1-2 is connected to the middle position of the top end of the hinge base through the middle support arm, and a bottom torsion hinge 1-1-8 and a top torsion hinge 1-1-14 are respectively arranged at the connection points between the middle support arm, the hinge base and the hinge top plate 1-1-2; the two sides of the bottom end of the hinge top plate 1-1-2 are respectively connected to the corresponding positions of the top end of the hinge base through the two side support arms, and the two side support arms are sequentially arranged with a bridge hinge 1-1-10, a bridge hinge 2 1-1-11, a bridge hinge 3 1-1-12 and a bridge hinge 4 1-1-13 from the connection point of the hinge base to the connection point of the hinge top plate 1-1-2, dividing the two side support arms into a three-section structure of an upper connecting block 1-1-3, a middle connecting block 1-1-4 and a lower connecting block 1-1-5. The bridge hinge 1-1-10 and the bridge hinge 4-1-13 of the two side arms are respectively used as the connection points with the hinge base and the hinge top plate 1-1-2, and are arranged at the outer edges of the two side arms. The bridge hinge 2-1-11 and the bridge hinge 3-1-12 of the two side arms are respectively used as the middle deformation points of the side arms, and are arranged at the inner edges of the two side arms. The two piezoelectric ceramics 1-2 are respectively installed in the two cavities between the middle arm and the two side arms of the torsion-driven flexible mechanism 1-1, and are supported between the hinge top plate 1-1-2 and the hinge base.

[0034] Hinge mechanism preload, combined Figure 2 to Figure 4As shown, the piezoelectric ceramic 1-2 is pre-tightened on the torsion-driven flexible mechanism 1-1, and the torsion-driven flexible mechanism 1-1 is pre-tightened on the platform base 2. In order to facilitate installation and provide pre-tightening force for the two piezoelectric ceramics 1-2, two pre-tightening hinges 1-1-9 are set at the top of the hinge base and the supporting points corresponding to the two piezoelectric ceramics 1-2, and two pre-tightening threaded holes 1-1-7 are machined along the axial direction of the two piezoelectric ceramics 1-2 at the bottom of the hinge base. By screwing in two pre-tightening bolts 1-3 to contact the corresponding pre-tightening hinges 1-1-9, the piezoelectric ceramics 1-2 are simply fixed relative to the torsion-driven flexible mechanism 1-1. According to the simulation results, the two pre-tightening bolts 1-3 need to be screwed in a fixed distance on this basis. Use an angle wrench to screw the two pre-tightening bolts 1-3 into the corresponding pre-tightening threaded holes 1-1-7 for a fixed distance. Then use the pre-installed locking nut 1-4 to tighten the corresponding pre-tightening bolt 1-3 in place and limit its screwing position to prevent slipping. In order to facilitate the fine-tuning of the installation position of the torsion-driven flexible mechanism 1-1 on the platform base 2, two long holes 2-1 are processed in the vertical direction of the platform top cover 4 at the corresponding positions of the platform base 2 and the two fixing bolts 1-5. After the two fixing bolts 1-5 pass through the two long holes 2-1, they are first screwed with single nuts in a loose state, and the piezoelectric flexible hinge driver 1 is moved toward the platform top cover 4 until the semi-cylindrical driving foot 1-1-1 just contacts the platform top cover 4. At this time, tighten the two fixing bolts 1-5. The single nut on the piezoelectric flexible hinge driver 1 is initially fixed to the platform base 2, and two fine-tuning threaded holes 2-2 are integrally arranged on the side edge of the platform base 2. The two fine-tuning threaded holes 2-2 are arranged correspondingly to the two sides of the bottom end of the hinge base of the torsion-driven flexible mechanism 1-1. The two sides of the bottom end of the hinge base are supported and limited by screwing in two fine-tuning bolts 2-3, and then the corresponding fine-tuning bolts 2-3 are tightened in place using the pre-installed locking nuts 2-4 to limit their screwing-in positions to prevent slipping.

[0035] Before formal use, power on the two piezoelectric ceramics 1-2 to test the output of the torsion-driven flexible mechanism 1-1, and fine-tune the position of the torsion-driven flexible mechanism 1-1 according to the output result. First, loosen the single nuts on the two fixing bolts 1-5 and the locking nuts 2-4 of the two fine-tuning bolts 2-3, and adjust the relative position of the piezoelectric flexible hinge driver 1 and the platform base 2 again through the two fine-tuning bolts 2-3. After adjustment, tighten the single nuts on the two fixing bolts 1-5 and the locking nuts 2-4 of the two fine-tuning bolts 2-3, and power on the two piezoelectric ceramics 1-2 again to test the output of the torsion-driven flexible mechanism 1-1. Repeat this process until a suitable output is obtained, and finally use double nuts to tighten the two fixing bolts 1-5 to prevent loosening.

[0036] like Figure 1 to Figure 5As shown, a driving method of a torsionally actuated piezoelectric stick-slip driving system comprises the following steps:

[0037] Before formal use, the torsion-driven flexible mechanism 1-1 and the two piezoelectric ceramics 1-2 are pre-tightened respectively. After power-on testing and adjustment, it is ensured that the piezoelectric flexible hinge driver 1 can perform appropriate output. During actual driving, only one side of the piezoelectric ceramics 1-2 expands and contracts at the same time (due to the inverse piezoelectric characteristics of the piezoelectric ceramics 1-2, after a certain voltage is applied to the piezoelectric ceramics 1-2, the piezoelectric ceramics 1-2 will stretch / shorten as the voltage changes). According to the requirements of the moving direction of the platform top cover 4, one side of the piezoelectric ceramics 1-2 is selected for powering on, and combined with Figure 5 As shown in the upper part, a sawtooth wave periodic voltage signal is loaded on the piezoelectric ceramic 1-2. In one cycle, the voltage is divided into two stages: rising and falling. The time of the voltage falling stage is shorter than the time of the voltage rising stage.

[0038] Voltage rising stage, combined with Figure 5 As shown in the middle part, the piezoelectric ceramic 1-2 on the powered side is stretched and output through the top of the torsion-driven flexible mechanism 1-1, causing the hinge top plate 1-1-2 to deflect toward the piezoelectric ceramic 1-2 on the other side, and the semi-cylindrical driving foot 1-1-1 is deflected accordingly. Since the semi-cylindrical driving foot 1-1-1 has been in contact with the platform top cover 4 before the piezoelectric ceramic 1-2 is stretched, at this time, the semi-cylindrical driving foot 1-1-1 and the platform top cover 4 mainly generate static friction, and then drive the platform top cover 4 to move toward the piezoelectric ceramic 1-2 on the other side under the static friction;

[0039] Voltage drop stage, combined with Figure 5 As shown in the middle part, the piezoelectric ceramic 1-2 on the power-on side is shortened. Since the voltage drop phase in one cycle is short, the shortening speed is fast. The deflected hinge top plate 1-1-2 quickly recovers its initial shape under the stress of the torsion-driven flexible mechanism 1-1. At this time, the semi-cylindrical driving foot 1-1-1 and the platform top cover 4 mainly generate sliding friction. The platform top cover 4 will not follow the semi-cylindrical driving foot 1-1-1 back to its original position due to inertia.

[0040] By repeating the periodic voltage rise and fall stages in this way, the piezoelectric flexible hinge driver 1 can control the platform top cover 4 to perform periodic step displacement output. If the platform top cover 4 needs to be controlled to move in the reverse direction, the powered piezoelectric ceramic 1-2 can be replaced.

[0041] Example

[0042] The reading head 6 and two piezoelectric ceramics 1-2 of the torsion actuated piezoelectric stick-slip drive system are connected to the controller 8, combined with Figure 6As shown, the reading head 6 cooperates with the grating ruler 7 fixed on the bottom surface of the platform top cover 4 to transmit the read displacement data of the platform top cover 4 to the controller 8. The controller 8 loads a sawtooth wave periodic voltage signal to the piezoelectric ceramic 1-2 on the left side, with a frequency of 100Hz, a voltage peak of 9.6V, a signal symmetry of 97%, a driving preload of 2N, and the translation stage is unloaded.

[0043] During the voltage rising stage, the piezoelectric ceramic 1-2 on the left side elongates due to its inverse piezoelectric effect, the hinge top plate 1-1-2 deflects to the upper right, and the semi-cylindrical driving foot 1-1-1 deflects accordingly. The upper connecting block 1-1-3, the middle connecting block 1-1-4 and the lower connecting block 1-1-5 corresponding to the left side arm also undergo relative displacement when the hinge top plate 1-1-2 deflects, wherein the upper connecting block 1-1-3 is displaced away from one side of the piezoelectric ceramic 1-2 and rotates clockwise, the middle connecting block 1-1-4 is displaced away from one side of the piezoelectric ceramic 1-2, the lower connecting block 1-1-5 is displaced away from one side of the piezoelectric ceramic 1-2 and rotates counterclockwise, and the upper connecting block 1-1-3, the middle connecting block 1-1-4 and the lower connecting block 1-1-5 corresponding to the right side arm produce relative displacement in the opposite direction to the above but with a slightly weaker amplitude. Since the semi-cylindrical driving foot 1-1-1 has been in contact with the platform top cover 4 before the piezoelectric ceramic 1-2 is extended, when the semi-cylindrical driving foot 1-1-1 is deflected to the upper right, its contact point with the platform top cover 4 simultaneously produces displacement to the right and upward. Since the upward displacement increases the friction force, the friction force between the semi-cylindrical driving foot 1-1-1 and the platform top cover 4 is mainly static friction, and the displacement to the right drives the platform top cover 4 to move to the right.

[0044] During the voltage drop stage, the piezoelectric ceramic 1-2 on the left side is also shortened due to its inverse piezoelectric effect. Since the voltage drop stage is short within one cycle, its shortening speed is fast. The deflected hinge top plate 1-1-2 quickly recovers to its initial shape under the stress of the torsion-driven flexible mechanism 1-1 (bottom torsion hinge 1-1-8, bridge hinge one 1-1-10, bridge hinge two 1-1-11, bridge hinge three 1-1-12, bridge hinge four 1-1-13, top torsion hinge 1-1-14), and the semi-cylindrical driving foot 1-1-1 is displaced to the left and downward. At this time, the platform top cover 4 cannot completely follow the semi-cylindrical driving foot 1-1-1 to move to the original position to the left due to inertia. The semi-cylindrical driving foot 1-1-1 and the platform top cover 4 mainly generate sliding friction. Due to the existence of sliding friction at this stage, the platform top cover 4 will not return to the initial position with the torsion-driven flexible mechanism 1-1.

[0045] The periodic voltage rise and fall phases are repeated in this way, so that the piezoelectric flexible hinge driver 1 controls the platform top cover 4 to perform periodic stepping displacement output to the right. Under this configuration environment, the minimum step length of the stepping motion of the displacement stage is measured to be 60nm, and the speed is 6μm / s.

[0046] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms of assembly without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0047] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A torsionally actuated piezoelectric stick-slip drive system, comprising a platform base (2), a platform cover (4) and two cross roller guides (3), wherein the platform cover (4) is slidably mounted on the surface of the platform base (2) via the two cross roller guides (3) arranged in parallel, and characterized in that: The drive system also includes a piezoelectric flexible hinge driver (1), which is composed of a torsion-driven flexible mechanism (1-1) and two piezoelectric ceramics (1-2). The torsion-driven flexible mechanism (1-1) is an integrated structure, including a hinge top plate (1-1-2) and a hinge base, and an intermediate support arm and two side support arms for connecting the two. A semi-cylindrical driving foot (1-1-1) is integrally arranged at the middle position of the top of the hinge top plate (1-1-2) and is arranged in contact with the side of the platform top cover (4). Two through holes (1-1-6) are arranged on both sides of the hinge base and are installed and fixed to the platform base (2) by two fixing bolts (1-5) combined with nuts. The intermediate support arm is connected to the hinge. A bottom torsion hinge (1-1-8) and a top torsion hinge (1-1-14) are respectively arranged at the connection points of the base and the hinge top plate (1-1-2); four bridge hinges are sequentially arranged on the two side arms from the connection point of the hinge base to the connection point of the hinge top plate (1-1-2) to divide the two side arms into three-section structures, wherein the first and last bridge hinges are used as connection points and arranged at the outer edges of the two side arms, and the middle two bridge hinges are arranged at the inner edges of the two side arms; the two piezoelectric ceramics (1-2) are respectively installed in two cavities between the middle arm and the two side arms of the torsion-driven flexible mechanism (1-1), and are supported between the hinge top plate (1-1-2) and the hinge base.

2. A torsionally actuated piezoelectric stick-slip drive system according to claim 1, characterized in that: A grating ruler (7) is fixed on the bottom surface of the platform top cover (4), and a reading head (6) is fixed at a corresponding position on the surface of the platform base (2). The movement of the platform top cover (4) is measured by the cooperation between the reading head (6) and the grating ruler (7).

3. A torsionally actuated piezoelectric stick-slip drive system according to claim 1 or 2, characterized in that: Two long holes (2-1) are processed in the platform base (2) and at positions corresponding to the two fixing bolts (1-5) along the vertical direction of the platform top cover (4).

4. A torsionally actuated piezoelectric stick-slip drive system according to claim 3, characterized in that: Two fine-tuning threaded holes (2-2) are integrally arranged on the side edge of the platform base (2); the two fine-tuning threaded holes (2-2) are arranged corresponding to the two sides of the bottom end of the hinge base; two fine-tuning bolts (2-3) are screwed into the two fine-tuning threaded holes (2-2) to support and limit the two sides of the bottom end of the hinge base; the two fine-tuning bolts (2-3) are respectively equipped with locking nuts (2-4).

5. The torsionally actuated piezoelectric stick-slip drive system according to claim 1, characterized in that: Two pre-tightened hinges (1-1-9) are arranged at the top end of the hinge base and at supporting points corresponding to the two piezoelectric ceramics (1-2).

6. A torsionally actuated piezoelectric stick-slip drive system according to claim 5, characterized in that: Two pre-tightening threaded holes (1-1-7) are machined along the axial direction of the two piezoelectric ceramics (1-2) at the bottom end of the hinge base; two pre-tightening bolts (1-3) are screwed into the two pre-tightening threaded holes (1-1-7) to contact corresponding pre-tightening hinges (1-1-9) to cause them to deform and pre-tighten and position the piezoelectric ceramics (1-2) relative to the torsion-driven flexible mechanism (1-1); and the two pre-tightening bolts (1-3) are respectively equipped with locking nuts (1-4).

7. A driving method for a torsionally actuated piezoelectric stick-slip drive system, characterized in that: According to the torsionally actuated piezoelectric stick-slip drive system of claim 1, the driving method thereof comprises the following steps: During the actual driving period, only one side of the piezoelectric flexible hinge driver (1) of the piezoelectric ceramic (1-2) is extended and retracted at the same time, and the piezoelectric ceramic (1-2) is selected to be powered on according to the moving direction requirement of the platform top cover (4), and a sawtooth wave periodic voltage signal is loaded on the piezoelectric ceramic (1-2), and the voltage is divided into two stages of rising and falling in one cycle; During the voltage rising stage, the piezoelectric ceramic (1-2) on the powered side is extended, causing the hinge top plate (1-1-2) to deflect, and the semi-cylindrical driving foot (1-1-1) drives the platform top cover (4) to move under static friction; During the voltage drop phase, the piezoelectric ceramic (1-2) on the power-on side is shortened, and the deflected hinge top plate (1-1-2) recovers its initial shape under the stress of the torsion-driven flexible mechanism (1-1). Due to the sliding friction and inertia, the platform top cover (4) does not follow the semi-cylindrical driving foot (1-1-1) back to its original position. By repeating the periodic voltage rising and falling stages in this way, the piezoelectric flexible hinge driver (1) controls the platform top cover (4) to perform periodic stepping displacement output.

8. The driving method of the torsionally actuated piezoelectric stick-slip driving system according to claim 7, characterized in that: In one cycle of the sawtooth wave periodic voltage signal, the duration of the voltage drop phase is shorter than the duration of the voltage rise phase.

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