A stepping actuator with self-adaptive adjustment capability and a coordinated control method thereof

Abstract

This invention discloses a stepper actuator with adaptive assembly and adjustment capabilities and its coordinated control method. It comprises symmetrical fixed ends, an output shaft arranged between the fixed ends, and a drive assembly installed between the fixed ends and the output shaft. The drive assembly consists of a rigid base, a flexible constraint structure, telescopic piezoelectric ceramics, shear piezoelectric ceramics, contact friction ends, and adjusting pads. This actuator effectively reduces the consistency requirements of the structure and piezoelectric ceramics by limiting the number of piezoelectric ceramics installed on the same rigid base, setting up a flexible adjustment mechanism and adjusting pads for initial adjustment, and dividing the control groups. This simplifies the assembly and debugging process and reduces elastic deformation disturbances during actuator operation.

Description

Technical Field

[0001] This invention relates to the field of electric drive technology, and more specifically to a stepper actuator with adaptive adjustment capability and its coordinated control method. Background Technology

[0002] In recent years, piezoelectric actuators have been continuously developing, supporting the development and construction of important industries such as national defense, aerospace, and machinery manufacturing. They have also spawned a wide variety of electric actuators, especially piezoelectric drive mechanisms which can achieve extremely high actuation accuracy. However, due to the limited actuation stroke of piezoelectric materials, piezoelectric ceramic actuators struggle to achieve large-stroke outputs, requiring different working principles to achieve large-stroke displacement outputs. Therefore, piezoelectric actuators that use multiple piezoelectric ceramics working in tandem to achieve actuation have attracted widespread attention from researchers. When using multiple piezoelectric ceramics for actuation, the increased number of ceramics places demands on their initial geometric dimensions and the consistency of assembly and adjustment. High precision in structural dimensional machining is required, and the piezoelectric ceramics and structural components must undergo matching and screening, resulting in high production costs and long manufacturing cycles for this type of stepper actuator. Summary of the Invention

[0003] To meet the above requirements, the present invention aims to provide a stepper actuator with adaptive adjustment capability and its coordinated control method, which is an elastic structure of a stepper actuator and its coordinated control method that can adapt to inconsistent heights of driving piezoelectric ceramics and resist structural elastic deformation disturbances.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A stepper actuator with adaptive adjustment capability includes an output shaft, a first fixed end and a second fixed end located on both sides of the output shaft, a plurality of mirror-symmetrically arranged drive components arranged between the first fixed end and the output shaft, and a plurality of mirror-symmetrically arranged drive components arranged between the second fixed end and the output shaft, wherein the drive components at both ends of the output shaft are mirror-symmetrically arranged about the centerline of the output shaft; the drive components satisfy a total number rule of 4N, where N is a positive integer; wherein four drive components constitute one drive component unit, and the four drive components in a drive component unit are mirror-symmetrically arranged in pairs about the centerline of the output shaft; The four drive components in the drive assembly unit have identical structures. One drive component includes a rigid base, flexible constraint structures arranged on both sides of the rigid base and connected to the first fixed end, an inner telescopic piezoelectric ceramic arranged on the rigid base, an inner shear piezoelectric ceramic arranged on the inner telescopic piezoelectric ceramic, an inner contact friction end arranged on the inner shear piezoelectric ceramic and in contact with the output shaft; an outer telescopic piezoelectric ceramic arranged on the rigid base and symmetrical with the inner telescopic piezoelectric ceramic around the center line of the rigid base, an outer shear piezoelectric ceramic arranged on the outer telescopic piezoelectric ceramic and symmetrical with the inner shear piezoelectric ceramic around the center line of the rigid base, an outer contact friction end arranged on the outer shear piezoelectric ceramic and symmetrical with the inner contact friction end around the center line of the rigid base and in contact with the output shaft; an inner adjusting pad arranged between the rigid base and the first fixed end and located below the inner telescopic piezoelectric ceramic; and an outer adjusting pad arranged between the rigid base and the first fixed end and located below the outer telescopic piezoelectric ceramic. The output shaft of the actuator performs a large-stroke bidirectional motion along the X direction under the coordinated operation of the four drive components in each drive component unit. The telescopic piezoelectric ceramic in the drive component telescopically deforms along the Y direction; the shear piezoelectric ceramic in the drive component shears along the X direction. In a single drive assembly, the inner telescopic piezoelectric ceramic and the outer telescopic piezoelectric ceramic have opposite motion states, with one extending while the other is in a retracted state; in a single drive assembly, the inner shear piezoelectric ceramic and the outer shear piezoelectric ceramic have opposite motion states, with one deforming to the left while the other deforms to the right. The initial error caused by the inconsistency between the total height of the inner telescopic piezoelectric ceramic, inner shear piezoelectric ceramic, and inner friction contact end in the drive component where the flexible constraint structure is located and the total height of the outer telescopic piezoelectric ceramic, outer shear piezoelectric ceramic, and outer friction contact end; during the above adaptive adjustment process, the drive component where the flexible constraint structure is located generates a small angular sway. By adjusting the pads, the corresponding friction contact end and the output shaft are made to have the same contact pressure, thereby eliminating the inconsistency in the contact pressure between the friction contact end and the output shaft caused by the different elastic deformations of the corresponding flexible constraint structure.

[0005] The stiffness of the flexible constraint structure in the drive assembly along the X direction of the output shaft movement is greater than its stiffness in the Y direction of the stretching deformation of the piezoelectric ceramic. This allows the flexible constraint structure to constrain the output shaft with a large X-direction stiffness while the drive assembly can produce a small angle of yaw and be adjustable. This gives the stepper actuator sufficient output direction stiffness.

[0006] By adjusting the pads based on their own installation position, the supporting force along the Y direction between the corresponding rigid base and the corresponding fixed end can be adjusted. Therefore, it has the ability to adjust for the size differences between the structure and the piezoelectric ceramic in the drive assembly. After adjustment, the pads provide structural support, which reduces the requirements of the stepper actuator for machining accuracy and the consistency of the geometric dimensions of the parts, and reduces the manufacturing cost and time of the stepper actuator.

[0007] The friction contact end of the drive assembly is a cube, a frustum, a chamfered cube or frustum, or a cylinder with a spherical contact surface with the output shaft 3.

[0008] The aforementioned coordinated control method for step-by-step actuation with adaptive adjustment capability controls the operation of the telescopic piezoelectric ceramic in a manner that is mirror-symmetrical along the Y-direction midline of the first fixed end and the second fixed end, and mirror-symmetrical along the X-direction midline of the output shaft among the four drive components of the drive component unit. The stepping motion control method of a stepper actuator is illustrated using one of the driving components. Initially, all piezoelectric ceramic voltages are zero, and the output shaft maintains static locking due to positive pressure between the contact friction end and the output shaft. First, the inner telescopic piezoelectric ceramic elongates, and the outer telescopic piezoelectric ceramic shortens. The friction between the inner contact friction end and the output shaft increases, while the friction between the outer contact friction end and the output shaft decreases. Second, the inner shear piezoelectric ceramic undergoes shear deformation along the positive X-axis of the output shaft, and the outer shear piezoelectric ceramic undergoes shear deformation along the negative X-axis of the output shaft. Because the friction between the inner contact friction end and the output shaft is greater than that between the outer contact friction end and the output shaft, the output shaft will move along the positive X-axis with the inner contact head. Third, the inner telescopic piezoelectric ceramic shortens, and the outer telescopic piezoelectric ceramic elongates. The friction between the inner contact friction end and the output shaft decreases, while the friction between the outer contact friction end and the output shaft increases. Fourth, the inner shear pressure... The inner shear piezoelectric ceramic undergoes shear deformation along the negative X-direction of the output shaft, while the outer shear piezoelectric ceramic undergoes shear deformation along the positive X-direction of the output shaft. Since the friction between the inner friction contact end and the output shaft is less than that between the outer friction contact end and the output shaft, the output shaft will move along the positive X-axis along with the outer friction contact end. In the fifth step, the inner telescopic piezoelectric ceramic elongates, and the outer telescopic piezoelectric ceramic shortens. The friction between the inner friction contact end and the output shaft increases, while the friction between the outer friction contact end and the output shaft decreases. After the fifth step, the second step is repeated, thus achieving continuous operation of the output shaft along the positive X-axis. During the drive process, the driving voltage of the inner telescopic piezoelectric ceramic, the inner shear piezoelectric ceramic, the outer telescopic piezoelectric ceramic, and the outer shear piezoelectric ceramic is restored to zero, thus exiting the large-stroke stepping working state and returning to the initial state before the first step. The shearing motion direction of the inner and outer shear piezoelectric ceramics is changed, thus achieving continuous operation of the output shaft along the negative X-axis.

[0009] The coordinated control method involves a first drive assembly positioned between the first fixed end and the output shaft. When the inner telescopic piezoelectric ceramic shortens and the outer telescopic piezoelectric ceramic extends, the first drive assembly exhibits a counter-clockwise movement tendency. In a third drive assembly, mirror-symmetrical to the first drive assembly about the centerline of the output shaft, when the inner telescopic piezoelectric ceramic shortens and the outer telescopic piezoelectric ceramic extends, the third drive assembly exhibits a clockwise movement tendency. The first and third drive assemblies together cause the output shaft to move along the positive X-axis. Correspondingly, a second drive assembly positioned between the first fixed end and the output shaft and mirror-symmetrical to the first drive assembly exhibits a clockwise movement tendency when the outer telescopic piezoelectric ceramic extends and the inner telescopic piezoelectric ceramic shortens. This second drive assembly is fixed between the second fixed end and the output shaft. In the fourth drive assembly, which is mirror-symmetrical to the third drive assembly, the outer telescopic piezoelectric ceramic elongates and the inner telescopic piezoelectric ceramic shortens. The fourth drive assembly has a quasi-clockwise motion tendency. The second and fourth drive assemblies together cause the output shaft to move in the negative X-axis direction. The disturbance tendencies of the first and third drive assemblies on the output shaft in the positive X-axis direction cancel each other out with the disturbance tendencies of the second and fourth drive assemblies on the output shaft in the negative X-axis direction, thereby eliminating the disturbance effect of the drive assembly rotation deformation on the output shaft. Conversely, the disturbance tendencies of the first and third drive assemblies on the output shaft in the negative X-axis direction cancel each other out with the disturbance tendencies of the second and fourth drive assemblies on the output shaft in the positive X-axis direction, similarly eliminating the disturbance effect of the drive assembly rotation deformation on the output shaft.

[0010] The stepper actuator of this invention limits the number of piezoelectric ceramics mounted on the same rigid substrate, sets up a flexible adjustment mechanism and adjustment pads for initial adjustment, and effectively reduces the consistency requirements of the structure and piezoelectric ceramics by dividing the control groups. This simplifies the assembly and debugging process and reduces elastic deformation disturbances during actuator operation. Compared with the prior art, this invention has the following advantages: 1. By using the elastic deformation of the grouped drive components, the drive assembly has adjustment capability, which reduces the requirements of the stepper actuator on the consistency of structure and piezoelectric ceramics; 2. Based on the elastic adjustment characteristics and driving method of the proposed driving structure, the coupling disturbance effect of the stepper driving process is reduced through a coordinated control method; 3. The drive component unit is scalable, and the device can be expanded according to the actuator driving force and volume space requirements. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a typical actuator device.

[0012] Figure 2 The structural form of the actuator leg end is optional.

[0013] Figure 3 This refers to the adjustment effect of the flexible constraint structure on the initial height of the drive component.

[0014] Figure 4-1 This is a forward continuous motion method. Figure 4-2 This is a method of reverse continuous motion.

[0015] Figure 5 This is a coupled motion caused by the extension of the supporting leg.

[0016] Figure 6 A balanced driving method is preferred to eliminate coupled motion.

[0017] Figure 7 Extended methods for 8 groups of driver components. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1As shown, this embodiment discloses a stepper actuator with adaptive adjustment capability, comprising an output shaft 3, a first fixed end 1 and a second fixed end 2 located on both sides of the output shaft 3, a first drive assembly 4 arranged between the first fixed end 1 and the output shaft 3, a second drive assembly 5 arranged between the first fixed end 1 and the output shaft 3 and mirror-symmetrical to the first drive assembly 4, a third drive assembly 6 arranged between the second fixed end 2 and the output shaft 3 and mirror-symmetrical to the first drive assembly 4 about the centerline of the output shaft 3, and a fourth drive assembly 7 fixed between the second fixed end 2 and the output shaft 3 and mirror-symmetrical to the third drive assembly 6. The first drive assembly 4 includes a first rigid base 4-1, a first flexible constraint structure 4-2 arranged on both sides of the first rigid base 4-1 and connected to the first fixed end 1, a first internal telescopic piezoelectric ceramic 4-3 arranged on the first rigid base 4-1, a first internal shear piezoelectric ceramic 4-4 arranged on the first internal telescopic piezoelectric ceramic 4-3, and a first internal contact friction end 4-5 arranged on the first internal shear piezoelectric ceramic 4-4 and in contact with the output shaft 3. A first external telescopic piezoelectric ceramic 4-7 is arranged on the first rigid base 4-1 and symmetrically with the first internal telescopic piezoelectric ceramic 4-3 around the centerline of the first rigid base 4-1. A first external shear piezoelectric ceramic 4-8 is arranged on the first external telescopic piezoelectric ceramic 4-7 and symmetrically with the first internal shear piezoelectric ceramic 4-4 around the centerline of the rigid base 4-1. A first external contact friction end 4-9 is arranged on the first external shear piezoelectric ceramic 4-8 and symmetrically with the first internal contact friction end 4-5 around the centerline of the first rigid base 4-1, contacting the output shaft 3. A first internal adjusting pad 4-6 is arranged between the first rigid base 4-1 and the first fixed end 1 and located below the first internal telescopic piezoelectric ceramic 4-3. A first external adjusting pad 4-10 is arranged between the first rigid base 4-1 and the first fixed end 1 and located below the first external telescopic piezoelectric ceramic 4-7.

[0020] The second drive assembly 5 has the same internal structural arrangement as the first drive assembly 4, including a second rigid base 5-1, a second flexible constraint structure 5-2, a second external telescopic piezoelectric ceramic 5-3, a second external shear piezoelectric ceramic 5-4, a second external contact friction end 5-5, a second internal telescopic piezoelectric ceramic 5-7, a second internal shear piezoelectric ceramic 5-8, a second internal contact friction end 5-9, a second external adjusting pad 5-6, and a second internal adjusting pad 5-10.

[0021] The third drive assembly 6 has the same internal structure arrangement as the first drive assembly 4, and is arranged in a mirror image of the first drive assembly 4 along the central axis of the output shaft 3. It includes a third rigid base 6-1, a third flexible constraint structure 6-2, a third inner telescopic piezoelectric ceramic 6-3, a third inner shear piezoelectric ceramic 6-4, a third inner contact friction end 6-5, a third outer telescopic piezoelectric ceramic 6-7, a third outer shear piezoelectric ceramic 6-8, a third outer contact friction end 6-9, a third inner adjusting pad 6-6, and a third outer adjusting pad 6-10.

[0022] The fourth drive assembly 7 has the same internal structure arrangement as the first drive assembly 4, and is arranged mirrorally with the second drive assembly 5 along the central axis of the output shaft 3. It includes a fourth rigid base 7-1, a fourth flexible constraint structure 7-2, a fourth external telescopic piezoelectric ceramic 7-3, a fourth external shear piezoelectric ceramic 7-4, a fourth external contact friction end 7-5, a fourth internal telescopic piezoelectric ceramic 7-7, a fourth internal shear piezoelectric ceramic 7-8, a fourth internal contact friction end 7-9, a fourth external adjusting pad 7-6, and a fourth internal adjusting pad 7-10.

[0023] In the actuator, the output shaft 3 can perform a large-stroke bidirectional movement along the X direction under the coordinated operation of four drive components 4, 5, 6, and 7. Specifically, the telescopic piezoelectric ceramics 4-3, 4-7, 5-3, 5-7, 6-3, 6-7, 7-3, and 7-7 in the four drive components 4, 5, 6, and 7 can telescopically deform along the Y direction. The shear piezoelectric ceramics 4-4, 4-8, 5-4, 5-8, 6-4, 6-8, and 7-4 and 7-8 in the four drive components 4, 5, 6, and 7 can shear deform along the X direction.

[0024] Among the four drive components 4, 5, 6, and 7 of the actuator, the friction contact ends 4-5, 4-9, 5-5, 5-9, 6-5, 6-9, 7-5, and 7-9 can be in various forms, such as cubes, frustums, chamfered cubes or frustums, or cylinders with spherical surfaces in contact with the output shaft 3.

[0025] The flexible constraint structures 4-2, 5-2, 6-2, and 7-2 in the four drive components 4, 5, 6, and 7 of the actuator have a stiffness in the X direction of the output shaft movement that is much greater than its stiffness in the Y direction of the telescopic deformation of the piezoelectric ceramic. Adjusting pads 4-6, 4-10, 5-6, and 5-10 can adjust the supporting force in the Y direction between the first rigid base 4-1, the second rigid base 5-1, and the first fixed end 1 based on their own installation positions; adjusting pads 6-6, 6-10, 7-6, and 7-10 can adjust the supporting force in the Y direction between the third rigid base 6 and the fourth rigid base 7 and the second fixed end 2 based on their own installation positions.

[0026] like Figure 3As shown in the attached left figure, in the actuator, the first flexible constraint structure 4-2 can adjust the initial error of the inconsistency between the total height of the first inner telescopic piezoelectric ceramic 4-3, the first inner shear piezoelectric ceramic 4-4, and the first inner friction contact end 4-5 and the total height of the first outer telescopic piezoelectric ceramic 4-7, the first outer shear piezoelectric ceramic 4-8, and the first outer friction contact end 4-9. During the aforementioned adaptive adjustment process, the first flexible constraint structure 4-2 can constrain the first driving component 4 to produce a small angular sway. The second flexible constraint structure 5-2 can adjust the initial error of the inconsistency between the total height of the second outer telescopic piezoelectric ceramic 5-3, the second outer shear piezoelectric ceramic 5-4, and the second outer friction contact end 5-5 and the total height of the second inner telescopic piezoelectric ceramic 5-7, the second inner shear piezoelectric ceramic 5-8, and the second inner friction contact end 5-9. During the aforementioned adaptive adjustment process, the second outer flexible constraint structure 5-2 can constrain the second outer driving component 5 to produce a small angular sway.

[0027] The first flexible constraint structure 4-2 and the second flexible constraint structure 5-2 can adjust the overall height of the first driving component 4 and the second driving component 5 to be different. During the above adaptive adjustment process, the first flexible constraint structure 4-2 can constrain the first driving component 4 to produce a small displacement in the Y direction, and the second flexible constraint structure 5-2 can constrain the second driving component 5 to produce a small displacement in the Y direction.

[0028] After the above adaptive adjustment process, by adjusting the pads 4-6, 4-10, 5-6, and 5-10, the friction contact ends 4-5, 4-9, 5-5, and 5-9 can be adjusted to have the same normal contact pressure with the output shaft 3. This eliminates the inconsistency in normal pressure between the friction contact ends and the output shaft 3 caused by the different elastic deformations of the first flexible constraint structure 4-2 and the second flexible constraint structure 5-2.

[0029] Similarly, the third flexible constraint structure 6-2 can adaptively adjust for the inconsistent height of the internal structure of the third drive assembly 6, and the fourth flexible constraint structure 7-2 can adaptively adjust for the inconsistent height of the internal structure of the fourth drive assembly 7. The third and fourth flexible constraint structures 6-2 can adjust the overall height difference between the third drive assembly 6 and the fourth drive assembly 7. Adjusting pads 6-6, 6-10, 7-6, and 7-10 can correspondingly adjust the friction contact ends 6-5, 6-9, 7-5, and 7-9 to ensure the same contact pressure between them and the output shaft 3.

[0030] like Figure 3 As shown in the attached diagram on the right, if there is no flexible constraint structure or adjusting pad in the design, the internal structural height of the drive component cannot be adaptively adjusted due to inconsistencies, and the total height of the drive components cannot be adjusted due to inconsistencies.

[0031] like Figure 4-1As shown, taking a single third drive component 6 as an example, the stepping motion control method of the stepper actuator is given. In the initial state, the voltage of all piezoelectric ceramics is zero, and the output shaft 3 has a positive pressure on the contact friction end, thus maintaining static locking. In the first step, the third inner telescopic piezoelectric ceramic 6-3 extends, the third outer telescopic piezoelectric ceramic 6-7 shortens, the friction between the third inner friction contact end 6-5 and the output shaft 3 increases, and the friction between the third outer friction contact end 6-9 and the output shaft 3 decreases. In the second step, the third inner shear piezoelectric ceramic 6-4 shears and deforms along the positive X direction of the output shaft, and the third outer shear piezoelectric ceramic 6-8 shears and deforms along the negative X direction of the output shaft. Since the friction between the third inner friction contact end 6-5 and the output shaft 3 is greater than the friction between the third outer friction contact end 6-9 and the output shaft 3, the output shaft 3 will move along the positive X direction with the third inner friction contact end 6-5. In the third step... In the first step, the third inner telescopic piezoelectric ceramic 6-3 shortens, the third outer telescopic piezoelectric ceramic 6-7 lengthens, the friction between the third inner friction contact end 6-5 and the output shaft 3 decreases, and the friction between the third outer friction contact end 6-9 and the output shaft 3 increases. In the second step, the third inner shear piezoelectric ceramic 6-4 undergoes shear deformation along the negative X direction of the output shaft, and the third outer shear piezoelectric ceramic 6-8 undergoes shear deformation along the positive X direction of the output shaft. Since the friction between the third inner friction contact end 6-5 and the output shaft 3 is less than the friction between the third outer friction contact end 6-9 and the output shaft 3, the output shaft 3 will move along the positive X-axis with the third outer friction contact end 6-9. In the third step, the third inner telescopic piezoelectric ceramic 6-3 lengthens, the third outer telescopic piezoelectric ceramic 6-7 shortens, the friction between the third inner friction contact end 6-5 and the output shaft 3 increases, and the friction between the third outer friction contact end 6-9 and the output shaft 3 decreases. After the fifth step, repeat the second step to achieve continuous operation of the output shaft 3 along the positive X-axis. During the driving process, restore the driving voltage of the third inner telescopic piezoelectric ceramic 6-3, the third inner shear piezoelectric ceramic 6-4, the third outer telescopic piezoelectric ceramic 6-7, and the third outer shear piezoelectric ceramic 6-8 to zero, and then exit the large stroke stepping working state and return to the initial state before the first step.

[0032] like Figure 4-2 As shown, by changing the shearing motion direction of the third inner shear piezoelectric ceramic 6-4 and the third outer shear piezoelectric ceramic 6-8, the output shaft 3 can be continuously operated along the negative X-axis.

[0033] like Figure 5 Taking the third drive component 6 as an example, during the operation of the telescopic piezoelectric ceramic, due to the generally high stiffness of the piezoelectric ceramic, the third flexible constraint structure 6-2, the third inner adjusting pad 6-6, the third outer adjusting pad 6-10, and even the second fixed end 2 will inevitably undergo elastic deformation, such as... Figure 5As shown, the trend of this elastic deformation can be understood as follows: as the third inner telescopic piezoelectric ceramic 6-3 elongates, the third outer telescopic piezoelectric ceramic 6-7 shortens, and the third rigid base 6-1 rotates counterclockwise; or as the third inner telescopic piezoelectric ceramic 6-3 shortens, the third outer telescopic piezoelectric ceramic 6-7 elongates, and the third rigid base 6-1 rotates clockwise. When the third rigid base 6-1 rotates counterclockwise, the output shaft will move in the negative X-axis direction; when the third rigid base 6-1 rotates clockwise, the output shaft will move in the positive X-axis direction. Therefore, the third inner telescopic piezoelectric ceramic 6-3 and the third outer telescopic piezoelectric ceramic 6-7 will cause disturbances in the X-direction of the output shaft 3. To avoid the above trend, this invention proposes a coordinated control method among the drive components 4, 5, 6, and 7.

[0034] like Figure 6 As shown, the implementation method of the balanced drive mode to eliminate coupled motion is as follows: First, in the single drive component 4 (or 5, 6, 7), the two telescopic piezoelectric ceramics 4-3 and 4-7 have opposite motion states, with one extending while the other is in a retracted state; Second, the two shear piezoelectric ceramics 4-4 and 6-8 in the single drive component have opposite motion states, with one deforming to the left while the other deforms to the right, such as... Figure 4-1 and 4-2 As shown; third, the driving components (4, 5, 6, 7) satisfy a total number rule of 4N, where N is a positive integer. When N=1, the following is adopted: Figure 6 The arrangement shown is adopted when N=2. Figure 7 The arrangement pattern shown; fourth, the drive component is mirror-symmetrical with respect to the center line of the X direction of the output shaft 3, and controls the operation of the telescopic piezoelectric ceramic in a symmetrical manner. The defined drive component is mirror-symmetrical with respect to the center line of the Y direction of the fixed end 2, and controls the operation of the telescopic piezoelectric ceramic in a symmetrical manner.

[0035] by Figure 6For example, in order to eliminate the disturbance effect, in each driving component, the telescopic piezoelectric ceramic is controlled to work in a manner that is mirror-symmetrical along the center line of the Y direction of the first fixed end 1 and the second fixed end 2, and mirror-symmetrical along the center line of the X direction of the output shaft 3. In the first drive assembly 4, when the first inner telescopic piezoelectric ceramic 4-3 shortens and the first outer telescopic piezoelectric ceramic 4-7 extends, the first drive assembly 4 has a counterclockwise movement tendency. In the third drive assembly 6, when the third inner telescopic piezoelectric ceramic 6-3 shortens and the third outer telescopic piezoelectric ceramic 6-7 extends, the third drive assembly 6 has a clockwise movement tendency. The first drive assembly 4 and the third drive assembly 6 together cause the output shaft 3 to move along the positive X-axis. Correspondingly, in the second drive assembly 5, when the second outer telescopic piezoelectric ceramic 5-3 extends and the second inner telescopic piezoelectric ceramic 5-7 shortens, the second drive assembly 5 has a clockwise movement tendency. In the fourth drive assembly 7, when the fourth outer telescopic piezoelectric ceramic 7-3 extends and the fourth inner telescopic piezoelectric ceramic 7-7 shortens, the fourth drive assembly 7 has a pseudo-clockwise movement tendency. The second drive assembly 5 and the fourth drive assembly 7 together cause the output shaft 3 to move along the negative X-axis. The disturbance tendencies of the first drive assembly 4 and the third drive assembly 6 on the output shaft 3 in the positive X-axis direction cancel each other out with the disturbance tendencies of the second drive assembly 5 and the fourth drive assembly 7 on the output shaft 3 in the negative X-axis direction, thereby eliminating the disturbance effect of the rotational deformation of the drive assembly on the output shaft 3. Conversely, when the telescopic piezoelectric ceramics 4-3, 5-7, 6-3, and 7-7 elongate and the telescopic piezoelectric ceramics 4-7, 5-3, 6-7, and 7-3 shorten, the disturbance tendencies of the first drive assembly 4 and the third drive assembly 6 on the output shaft 3 in the negative X-axis direction cancel each other out with the disturbance tendencies of the second drive assembly 5 and the fourth drive assembly 7 on the output shaft 3 in the positive X-axis direction, similarly eliminating the disturbance effect of the rotational deformation of the drive assembly on the output shaft 3.

[0036] The driving method described in this invention can also be extended to the motion control of more driving components, such as... Figure 7 As shown, this is an arrangement of eight drive components and its coordinated control method. The telescopic piezoelectric ceramics in drive components 4, 5, 6, 7, 8, 9, 10, and 11 are mirror-symmetrical along the Y-direction centerline of the first fixed end 1 and the second fixed end 2, and mirror-symmetrical along the X-direction centerline of the output shaft 3 to control the operation of the telescopic piezoelectric ceramics.

Claims

1. A stepper actuator with adaptive adjustment capability, characterized in that: The system includes an output shaft, a first fixed end and a second fixed end located on both sides of the output shaft, multiple mirror-symmetrically arranged drive components between the first fixed end and the output shaft, and multiple mirror-symmetrically arranged drive components between the second fixed end and the output shaft. The drive components at both ends of the output shaft are mirror-symmetrically arranged about the center line of the output shaft. The drive components satisfy a total number rule of 4N, where N is a positive integer. Four drive components constitute one drive component unit, and the four drive components in a drive component unit are mirror-symmetrically arranged in pairs about the center line of the output shaft. The four drive components in the drive component unit have the same structure. One of the drive components includes a rigid base, a flexible constraint structure arranged on both sides of the rigid base and connected to the first fixed end, an inner telescopic piezoelectric ceramic arranged on the rigid base, an inner shear piezoelectric ceramic arranged on the inner telescopic piezoelectric ceramic, and an inner contact friction end arranged on the inner shear piezoelectric ceramic and in contact with the output shaft. An outer telescopic piezoelectric ceramic arranged on a rigid base and symmetrical with the inner telescopic piezoelectric ceramic around the centerline of the rigid base; an outer shear piezoelectric ceramic arranged on the outer telescopic piezoelectric ceramic and symmetrical with the inner shear piezoelectric ceramic around the centerline of the rigid base; and an outer contact friction end arranged on the outer shear piezoelectric ceramic and symmetrical with the inner contact friction end around the centerline of the rigid base, which contacts the output shaft. An inner adjusting pad is arranged between the rigid base and the first fixed end, and located below the inner telescopic piezoelectric ceramic; an outer adjusting pad is arranged between the rigid base and the first fixed end, and located below the outer telescopic piezoelectric ceramic. The output shaft of the actuator performs a large-stroke bidirectional motion along the X direction under the coordinated operation of the four drive components in each drive component unit. The telescopic piezoelectric ceramic in the drive component telescopically deforms along the Y direction; the shear piezoelectric ceramic in the drive component shears along the X direction. In a single drive assembly, the inner telescopic piezoelectric ceramic and the outer telescopic piezoelectric ceramic have opposite motion states, with one extending while the other is in a retracted state; in a single drive assembly, the inner shear piezoelectric ceramic and the outer shear piezoelectric ceramic have opposite motion states, with one deforming to the left while the other deforms to the right. The initial error caused by the inconsistency between the total height of the inner telescopic piezoelectric ceramic, inner shear piezoelectric ceramic, and inner friction contact end in the drive component where the flexible constraint structure is located and the total height of the outer telescopic piezoelectric ceramic, outer shear piezoelectric ceramic, and outer friction contact end; during the above adaptive adjustment process, the drive component where the flexible constraint structure is located generates a small angular sway. By adjusting the pads, the corresponding friction contact end and the output shaft are made to have the same contact pressure, thereby eliminating the inconsistency in the contact pressure between the friction contact end and the output shaft caused by the different elastic deformations of the corresponding flexible constraint structure.

2. The stepper actuator with adaptive adjustment capability according to claim 1, characterized in that: The stiffness of the flexible constraint structure in the drive assembly along the X direction of the output shaft movement is greater than its stiffness in the Y direction of the stretching deformation of the piezoelectric ceramic.

3. The stepper actuator with adaptive adjustment capability according to claim 1, characterized in that: The support force along the Y direction between the corresponding rigid base and the corresponding fixed end is adjusted by adjusting the pad according to its own installation position.

4. The stepper actuator with adaptive adjustment capability according to claim 1, characterized in that: The friction contact end of the drive assembly is a cube, a frustum, a chamfered cube or frustum, or a cylinder with a spherical contact surface with the output shaft 3.

5. The coordinated control method for step-type actuation with adaptive adjustment capability as described in any one of claims 1 to 4, characterized in that: Among the four drive components of the drive component unit, the telescopic piezoelectric ceramic is controlled to work in a manner that is mirror-symmetrical along the Y-direction midline of the first fixed end and the second fixed end, and mirror-symmetrical along the X-direction midline of the output shaft. The stepping motion control method of a stepper actuator is illustrated using one of the driving components. Initially, all piezoelectric ceramic voltages are zero, and the output shaft maintains static locking due to positive pressure between the contact friction end and the output shaft. First, the inner telescopic piezoelectric ceramic elongates, and the outer telescopic piezoelectric ceramic shortens. The friction between the inner contact friction end and the output shaft increases, while the friction between the outer contact friction end and the output shaft decreases. Second, the inner shear piezoelectric ceramic undergoes shear deformation along the positive X-axis of the output shaft, and the outer shear piezoelectric ceramic undergoes shear deformation along the negative X-axis of the output shaft. Because the friction between the inner contact friction end and the output shaft is greater than that between the outer contact friction end and the output shaft, the output shaft will move along the positive X-axis with the inner contact head. Third, the inner telescopic piezoelectric ceramic shortens, and the outer telescopic piezoelectric ceramic elongates. The friction between the inner contact friction end and the output shaft decreases, while the friction between the outer contact friction end and the output shaft increases. Fourth, the inner shear pressure... The inner shear piezoelectric ceramic undergoes shear deformation along the negative X-direction of the output shaft, while the outer shear piezoelectric ceramic undergoes shear deformation along the positive X-direction of the output shaft. Since the friction between the inner friction contact end and the output shaft is less than that between the outer friction contact end and the output shaft, the output shaft will move along the positive X-axis along with the outer friction contact end. In the fifth step, the inner telescopic piezoelectric ceramic elongates, and the outer telescopic piezoelectric ceramic shortens. The friction between the inner friction contact end and the output shaft increases, while the friction between the outer friction contact end and the output shaft decreases. After the fifth step, the second step is repeated, thus achieving continuous operation of the output shaft along the positive X-axis. During the drive process, the driving voltage of the inner telescopic piezoelectric ceramic, the inner shear piezoelectric ceramic, the outer telescopic piezoelectric ceramic, and the outer shear piezoelectric ceramic is restored to zero, thus exiting the large-stroke stepping working state and returning to the initial state before the first step. The shearing motion direction of the inner and outer shear piezoelectric ceramics is changed, thus achieving continuous operation of the output shaft along the negative X-axis.

6. The coordinated control method according to claim 5, characterized in that: In the first drive assembly arranged between the first fixed end and the output shaft, when the inner telescopic piezoelectric ceramic shortens and the outer telescopic piezoelectric ceramic extends, the first drive assembly has a counterclockwise movement tendency. In the third drive assembly, which is mirror-symmetrical to the first drive assembly about the centerline of the output shaft, when the inner telescopic piezoelectric ceramic shortens and the outer telescopic piezoelectric ceramic extends, the third drive assembly has a clockwise movement tendency. The first and third drive assemblies together cause the output shaft to move along the positive X-axis. Correspondingly, in the second drive assembly arranged between the first fixed end and the output shaft and mirror-symmetrical to the first drive assembly, when the outer telescopic piezoelectric ceramic extends and the inner telescopic piezoelectric ceramic extends, the inner telescopic piezoelectric ceramic extends and the outer ... The piezoelectric ceramic shortens, the second drive assembly has a clockwise tendency, and the fourth drive assembly, which is fixed between the second fixed end and the output shaft and is mirror-symmetrical to the third drive assembly, has an elongated outer telescopic piezoelectric ceramic and a shortened inner telescopic piezoelectric ceramic. The fourth drive assembly has a quasi-clockwise tendency, and the second and fourth drive assemblies together cause the output shaft to move in the negative X-axis direction. The disturbance tendencies of the first and third drive assemblies on the output shaft in the positive X-axis direction are canceled out by the disturbance tendencies of the second and fourth drive assemblies on the output shaft in the negative X-axis direction, thereby eliminating the disturbance effect of the rotational deformation of the drive assembly on the output shaft. Conversely, the disturbance trends of the first and third drive components on the output shaft in the negative X-axis direction cancel each other out with the disturbance trends of the second and fourth drive components on the output shaft 3 in the positive X-axis direction, thus eliminating the disturbance effect of the rotational deformation of the drive components on the output shaft.

Images