Butterfly-Type Electromagnetic-Assisted Precision Piezoelectric Inertial Actuator and Driving Method

Abstract

The present invention provides a butterfly-type electromagnetic-assisted precision piezoelectric inertial actuator and a driving method, which combines an electromagnetic driving component based on the voice coil motor driving principle with a piezoelectric driving component based on the piezoelectric inertial driving principle. Among them, the coil unit in the electromagnetic driving component serves as the mover to improve the response speed and driving acceleration. The piezoelectric driving component uses piezoelectric wafers for driving, which has the advantage of low cost. By utilizing the characteristic that the piezoelectric driver is not affected by electromagnetic interference, on the one hand, the electromagnetic force is used to assist in suppressing the displacement retraction movement of the piezoelectric inertial driver, and on the other hand, the composite of the two driving sources of electromagnetic and piezoelectric is used to improve the overall comprehensive output performance of the machine. While effectively improving its thrust load, driving speed, suppressing displacement retraction and oscillation, it can also ensure high-precision positioning.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-precision machining and positioning, and particularly relates to a butterfly-type electromagnetic-assisted precision piezoelectric inertial actuator and a driving method thereof. Background Art

[0002] Precision positioning is the key to nanoscale control, measurement, and manufacturing, and has wide applications in engineering practice, including fields such as nanotechnology, aerospace, bioengineering, semiconductor manufacturing, and optical engineering. Piezoelectric materials have many advantages, such as sub-picometer resolution, long service life, and compact structure. Therefore, various types of piezoelectric actuators have been successively developed to achieve sub-nanometer accuracy. For example, piezoelectric stacks combined with flexible hinge mechanisms are widely used in micro-imaging, nanoscale operation, and nanomachining. However, the maximum displacement of such actuators is usually less than a few hundred micrometers. It is difficult to achieve large-stroke precision positioning.

[0003] The piezoelectric inertial drive nano-positioning system utilizes the stick-slip mechanism and can achieve high resolution and long stroke. In this mechanism, an asymmetric waveform is used to drive the piezoelectric actuator to generate alternating slow and fast movements, such as a sawtooth wave. During the slow movement, the piezoelectric actuator drives the slider through friction. During the fast movement, the slider will be subject to dynamic friction. When the sliding friction force received by the slider is greater than the inertial force generated by the slider due to the driving in the sticking stage, displacement retraction will occur, moving back a small step, and a small net displacement output will be generated within one cycle. By exciting with a periodic electrical signal, a stepping cycle is realized. The problem of displacement retraction generated by the actuator during the sliding stage will lead to the occurrence of displacement retraction movement, deteriorate the driving speed, and also exacerbate wear. The serrated displacement is more difficult to achieve high-precision positioning control, and this problem will be more severe under the thrust load condition. Summary of the Invention

[0004] Aiming at the technical problems that the traditional electromagnetic drive has low precision, the piezoelectric inertial drive has high precision but has the problem of displacement retraction, and the piezoelectric inertial actuator based on the inertial impact principle is difficult to achieve high-speed driving, the present invention proposes a butterfly-type electromagnetic-assisted precision piezoelectric inertial actuator and a driving method thereof.

[0005] The technical solution of the present invention is as follows:

[0006] The present invention first provides a butterfly-type electromagnetic-assisted precision piezoelectric inertial actuator, including an electromagnetic drive assembly, a piezoelectric drive assembly, and a base assembly;

[0007] The electromagnetic drive assembly includes a coil unit and a magnet unit arranged coaxially. The coil unit is sleeved in the magnet unit, and the two are in clearance fit; wherein the magnet unit is fixedly connected to the base assembly, and the coil unit is fixedly connected to the piezoelectric drive assembly;

[0008] The piezoelectric drive assembly includes a mover frame and four piezoelectric sheets; the mover frame includes a mover frame end plate, two mover frame side arms arranged on both sides of the mover frame end plate, a semi-circular boss arranged on the upper end of the mover frame end plate, and a mover frame mounting plate arranged on the lower end of the mover frame end plate; one piezoelectric sheet is fixed on both the upper and lower surfaces of the mover frame side arm, and the polarization directions of the piezoelectric sheets on the upper and lower surfaces are different, and the polarization directions of the piezoelectric sheets on the same side of the two mover frame side arms are the same; the mover frame end plate is used to abut against the coil unit, and the coil unit is fixedly arranged on the semi-circular boss; the base assembly includes a base, a limit plate, a guide rail and a slider; the base includes a base bottom plate and a magnet unit mounting plate; the magnet unit mounting plate is vertically arranged at one end of the base bottom plate; a limit plate is arranged at the other end of the base bottom plate; the guide rail is fixed on the base bottom plate, and the direction of the guide rail is perpendicular to the magnet unit mounting plate; the slider is slidably arranged on the guide rail, and the upper surface of the slider is fixed to the mover frame mounting plate.

[0009] According to a preferred embodiment of the present invention, the base further includes two base side plates, and the two base side plates are respectively vertically arranged on the base bottom plate. An inertial block is fixed to one end of each of the four piezoelectric sheets away from the mover frame end plate. The bending direction of the frame side arm, the moving direction of the slider, and the moving direction of the magnet unit are parallel to each other; the vibration direction of the piezoelectric stack is perpendicular to the above-mentioned moving direction.

[0010] According to a preferred embodiment of the present invention, the limit plate is of a concave structure, and the limit plate includes a limit plate main board and two limit plate arc-shaped bosses; the two limit plate arc-shaped bosses are symmetrically arranged on both sides of the top of the limit plate main board, and the radian of the limit plate arc-shaped boss matches the lower end of the mover frame end plate; an avoidance groove is formed between the two limit plate arc-shaped bosses, and the avoidance groove is used to prevent interference between the mover frame and the limit plate when the mover frame moves along with the slider.

[0011] According to a preferred embodiment of the present invention, the bending direction of the frame side arm is opposite to the direction of the reaction force received by the slider.

[0012] The present invention also provides a driving method for the above-mentioned butterfly-type electromagnetic-assisted precision piezoelectric inertial actuator:

[0013] It is stipulated that the rightward movement is the positive direction, and it is stipulated that applying a positive voltage is applying a positive direct current, and applying a negative voltage is applying a reverse direct current;

[0014] During forward driving, a reverse direct current is passed through the electromagnetic drive assembly; since the magnet unit is fixed on the base, the leftward force F m received by it will be offset by the reaction force of the bottom frame, and the coil unit will receive a rightward force F c, and drive the slider to have a tendency to move to the right; the contact surface between the piezoelectric sheet and the side arm of the mover frame in the piezoelectric drive assembly is grounded at 0 potential. At this time, a sawtooth wave with a duty cycle of 0% is applied to the surfaces of the four piezoelectric sheets that are not in contact with the side arm of the frame. Among them, the surfaces of the 4 piezoelectric sheets in contact with the side arm of the frame are grounded, and the surfaces not in contact with the side arm of the frame are input in parallel and then a sawtooth wave signal is applied; when the voltage rises rapidly, the 4 piezoelectric sheets drive the side arm of the mover frame to quickly change from bending to the right to bending to the left, and the reaction force F generated by the piezoelectric sheet driving the side arm of the mover frame to swing quickly P1 will act on the slider. At this time, the reaction force F P1 is in the right direction; when the voltage drops slowly, the 4 piezoelectric sheets drive the side arm of the mover frame to slowly change from deforming to the left to deforming to the right, and the reaction force F generated by the piezoelectric sheet driving the side arm of the mover frame to swing quickly P2 will act on the slider. At this time, the reaction force F P2 is in the left direction; due to the difference in the asymmetric duty cycle change of the voltage, the inertial force F P1 will be greater than F P2 ; calibrate the friction force between the slider and the guide rail with F f . When the voltage rises rapidly, the resultant force F T received by the slider = F c +F P1 -F f ; when the voltage drops slowly, the resultant force received by the slider is F T = F c -F P2 -F f ; by controlling the electrical signals between the electromagnetic drive assembly and the piezoelectric drive assembly, the forward drive of the composite positioning table is realized, and two modes can be executed, namely the fast drive mode and the precision positioning mode; when the fast drive mode is executed, the control electrical signal makes the resultant force received by the slider always greater than 0, and the electromagnetic drive assembly applies a large DC negative voltage so that the slider obtains a large resultant force F T ; when the precision positioning mode is executed, the electrical signal of the electromagnetic drive assembly is controlled so that the resultant force received by the slider is 0 when the voltage of the piezoelectric drive assembly drops slowly, so as to suppress the displacement regression generated during the independent displacement of the piezoelectric drive assembly in this stage, and a periodic sawtooth wave is applied to the piezoelectric drive to achieve micro-feed.

[0015] During reverse drive, a positive direct current is applied to the electromagnetic drive assembly. At this time, the coil unit receives a force F c to the left, and drives the slider to have a tendency to move to the left; the contact surface between the piezoelectric sheet and the side arm of the mover frame in the piezoelectric drive assembly is grounded at 0 potential, and a sawtooth wave voltage signal with a duty cycle of 100% is applied to the surfaces of the four piezoelectric sheets that are not in contact with the side arm of the frame. When the voltage rises slowly, the resultant force received by the slider is F T = F c -F P2-F f When the voltage drops rapidly, the resultant force on the slider is F T = F c + F P1 -F f where, due to the application of the asymmetric excitation signal, there is F P1 > F P2 ; Similar to the forward working principle, two working modes of fast driving and precise positioning can also be achieved during reverse driving.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention utilizes the characteristic that the piezoelectric actuator is not affected by electromagnetic interference. On the one hand, it suppresses the displacement retraction movement of the piezoelectric inertial actuator through electromagnetic force assistance. On the other hand, it improves the overall comprehensive output performance of the whole machine by combining two driving sources of electromagnetic and piezoelectric. While effectively improving its thrust load, driving speed, suppressing displacement retraction and oscillation, it can also ensure its high-precision positioning.

[0018] The present invention only has a pair of friction pairs of guide rail and slider. Through lubrication treatment, the whole machine can be ensured to have good wear resistance and service life. By controlling the input electrical signals of the electromagnetic driving component and the piezoelectric driving component, two working modes of fast driving and precise positioning can be achieved.

[0019] The present invention has great application prospects in the fields of active optics, sample movement in super-resolution imaging, micro-nano assembly and manufacturing, integrated circuit manufacturing and detection, sample manipulation in scanning electron microscopy, large-range electron beam direct writing, fiber and nano-CT, high-vacuum sample precision alignment and attitude adjustment, nano-focusing and scanning, etc. Description of the Drawings

[0020] Figure 1 is the overall schematic diagram of the butterfly-shaped electromagnetic-assisted precision piezoelectric inertial actuator;

[0021] Figure 2 is the structural schematic diagram of the electromagnetic driving component;

[0022] Figure 3 is the structural schematic diagram of the piezoelectric driving component;

[0023] Figure 4 is the structural schematic diagram of the mover frame;

[0024] Figure 5 is the structural schematic diagram of the base assembly;

[0025] Figure 6 is the structural schematic diagram of the base;

[0026] Figure 7 is the structural schematic diagram of the limit plate;

[0027] Figure 8 It is the working principle diagram of a butterfly-shaped electromagnetic-assisted precision piezoelectric inertial actuator.

[0028] In the figure: electromagnetic drive assembly 1, piezoelectric drive assembly 2, base assembly 3, coil unit 1-1, coil unit threaded hole 1-2, magnet unit 1-3, magnet unit threaded hole 1-4, mover frame 2-1, piezoelectric sheet I 2-2, piezoelectric sheet II 2-3, piezoelectric sheet III 2-4, piezoelectric sheet IV 2-5, inertial block I 2-6, inertial block II 2-7, inertial block III 2-8, inertial block IV 2-9, mover frame side arm 2-1-1, drive body mounting hole 2-1-2, wire arrangement hole 2-1-3, frame assembly counterbore 2-1-4, mover frame end plate 2-1-5, semi-circular boss 2-1-6, mover frame mounting plate 2-1-7, mover frame assembly counterbore 2-1-8, frame end face chamfer 2-1-9, base 3-1, limit plate 3-2, guide rail 3-3, slider 3-4, base bottom plate 3-1-1, magnet unit mounting plate 3-1-2, base side plate 3-1-3, base side plate arc-shaped groove 3-1-4, base side plate chamfer 3-1-5, guide rail fixing threaded hole 3-1-6, base mounting hole 3-1-7, limit plate assembly surface 3-1-8, limit plate fixing threaded hole 3-1-9, magnet assembly counterbore 3-1-10, avoidance groove 3-2-1, limit plate chamfer 3-2-2, limit plate arc-shaped boss 3-2-3, limit plate main board 3-2-4, limit plate assembly counterbore 3-2-5. Specific embodiments

[0029] The following further elaborates and explains the present invention in combination with specific embodiments. The described embodiments are only demonstrations of the present disclosure content and do not delimit the scope of limitation. Without conflict, the technical features of each embodiment in the present invention can be combined accordingly.

[0030] The overall schematic diagram of the butterfly-shaped electromagnetic-assisted precision piezoelectric inertial actuator and driving method designed by the present invention is as Figure 1 shown, mainly including an electromagnetic drive assembly 1, a piezoelectric drive assembly 2, and a base assembly 3;

[0031] The electromagnetic drive assembly includes a coil unit 1-1 and a magnet unit 1-3. The coil unit 1-1 is sleeved in the magnet unit 1-3, and the two are in clearance fit; among them, the magnet unit is fixedly connected to the base assembly, and the coil unit is fixedly connected to the piezoelectric drive assembly;

[0032] The piezoelectric drive assembly 2 includes a mover frame 2-1, four piezoelectric sheets, and four inertial blocks; the mover frame 2-1 includes a mover frame end plate 2-1-5, two mover frame side arms 2-1-1 disposed on both sides of the mover frame end plate 2-1-5, a semi-circular boss 2-1-6 disposed on the upper end of the mover frame end plate 2-1-5, and a mover frame mounting plate 2-1-7 disposed on the lower end of the mover frame end plate 2-1-5; one piezoelectric sheet is fixed on each of the upper and lower surfaces of the mover frame side arm 2-1-1, and the polarization directions of the piezoelectric sheets on the upper and lower surfaces are different, and the polarization directions of the piezoelectric sheets on the same side of the two mover frame side arms 2-1-1 are the same; an inertial block is fixed at one end of the piezoelectric sheet away from the mover frame end plate 2-1-5; the mover frame end plate 2-1-5 is used to abut against the coil unit 1-1, and the semi-circular boss 2-1-6 is used to fix the coil unit 1-1 on the mover frame 2-1; the mover frame mounting plate 2-1-7 is used to mount the piezoelectric drive assembly 2 on the base assembly 3;

[0033] The base assembly 3 includes a base 3-1, a limit plate 3-2, a guide rail 3-3, and a slider 3-4; the base 3-1 includes a base bottom plate 3-1-1 and a magnet unit mounting plate 3-1-2; the magnet unit mounting plate 3-1-2 is vertically disposed at one end of the base bottom plate 3-1-1; a limit plate 3-2 is disposed at the other end of the base bottom plate 3-1-1; the guide rail 3-3 is fixed on the base bottom plate 3-1-1 and the direction of the guide rail 3-3 is perpendicular to the magnet unit mounting plate 3-1-2; the slider 3-4 is slidably disposed on the guide rail 3-3, and the upper surface of the slider 3-4 is fixed to the mover frame mounting plate 2-1-7.

[0034] The limit plate 3-2 is of a concave structure, and the limit plate 3-2 includes a limit plate main board 3-2-4 and two limit plate arc-shaped bosses 3-2-3; the two limit plate arc-shaped bosses 3-2-3 are symmetrically disposed on both sides of the top of the limit plate main board 3-2-4, and the radian of the limit plate arc-shaped boss 3-2-3 matches the lower end of the mover frame end plate 2-1-5; an avoidance groove 3-2-1 is formed between the two limit plate arc-shaped bosses 3-2-3, and the avoidance groove 3-2-1 is used to prevent interference between the mover frame and the limit plate 3-2 when the mover frame moves along with the slider 3-4.

[0035] In a specific embodiment of the present invention, the electromagnetic drive assembly 1 is as Figure 2As shown in the figure, it is composed of a coil unit 1-1, a coil unit threaded hole 1-2, a magnet unit 1-3, and a magnet unit threaded hole 1-4; the piezoelectric drive assembly 2 includes a mover frame 2-1, a piezoelectric sheet I 2-2, a piezoelectric sheet II 2-3, a piezoelectric sheet III 2-4, a piezoelectric sheet IV 2-5, an inertia block I 2-6, an inertia block II 2-7, an inertia block III 2-8, and an inertia block IV 2-9; the mover frame 2-1 is provided with a mover frame side arm 2-1-1, a drive body mounting hole 2-1-2, a wire arrangement hole 2-1-3, a frame assembly countersunk hole 2-1-4, a mover frame end plate 2-1-5, a semi-circular boss 2-1-6, a mover frame mounting plate 2-1-7, a mover frame assembly countersunk hole 2-1-8, and a frame end face chamfer 2-1-9; a screw is used to pass through the base assembly 3 and screw into the magnet unit threaded hole 1-4 to fix the magnet unit 1-3 on the base assembly 3; the coil unit 1-1 is sleeved in the magnet unit 1-3, and the two are in clearance fit; the coil unit 1-1 abuts against the mover frame end plate 2-1-5 and is in contact fit with the semi-circular boss 2-1-6, and a screw is used to pass through the frame assembly countersunk hole 2-1-4 and screw into the coil unit threaded hole 1-2 to fix the coil unit 1-1 on the mover frame 2-1; the piezoelectric sheet I 2-2, the piezoelectric sheet II 2-3, the piezoelectric sheet III 2-4, the piezoelectric sheet IV 2-5, the inertia block I 2-6, the inertia block II 2-7, the inertia block III 2-8, and the inertia block IV 2-9 are all fixedly connected by adhesive to one end of the mover frame side arm 2-1-1 away from the mover frame end plate 2-1-5; the piezoelectric sheet I 2-2 and the piezoelectric sheet III 2-4 have the same polarization direction; the piezoelectric sheet II 2-3 and the piezoelectric sheet IV 2-5 have the same polarization direction and are opposite to the polarization directions of the former two; wherein, the excitation electric signals controlling the piezoelectric sheet I 2-2, the piezoelectric sheet II 2-3, the piezoelectric sheet III 2-4, and the piezoelectric sheet IV 2-5 can control the vibration of the mover frame side arm 2-1-1, and the inertia block I 2-6, the inertia block II 2-7, the inertia block III 2-8, and the inertia block IV 2-9 play a role in amplifying the amplitude; the drive body mounting hole 2-1-2 is used for the assembly of the driven target object, and the wire arrangement hole 2-1-3 is used for leading out the wires of the coil unit 1-1; a screw is used to pass through the mover frame assembly countersunk hole 2-1-8 to fix the mover frame 2-1 on the base assembly 3, wherein the mover frame mounting plate 2-1-7 is in contact with the base assembly 3; the frame end face chamfer 2-1-9 is provided to remove burrs and beautify the overall appearance of the machine;

[0036] In a specific embodiment of the present invention, the base assembly 3 is as shown in Figure 5 the figure, and it is composed of a base 3-1, a limit plate 3-2, a guide rail 3-3, and a slider 3-4; the structural schematic diagram of the base 3-1 is as shown in Figure 6As shown, it is provided with a base bottom plate 3-1-1, a magnet unit mounting plate 3-1-2, base side plates 3-1-3, an arc-shaped groove 3-1-4 on the base side plate, a chamfer 3-1-5 on the base side plate, a guide rail fixing threaded hole 3-1-6, a base mounting hole 3-1-7, a limiting plate assembly surface 3-1-8, a limiting plate fixing threaded hole 3-1-9 and a magnet assembly counterbore 3-1-10; The structural schematic diagram of the limiting plate 3-2 is as shown in Figure 7 As shown, it includes an avoidance groove 3-2-1, a chamfer 3-2-2 on the limiting plate, an arc-shaped boss 3-2-3 on the limiting plate, a main board 3-2-4 of the limiting plate and a counterbore 3-2-5 for the limiting plate assembly; The guide rail 3-3 is attached to the base bottom plate 3-1-1, and screws are passed through the guide rail 3-3 and screwed into the guide rail fixing threaded hole 3-1-6 to fix it to the base 3-1; The slider 3-4 and the guide rail 3-3 are connected by a profile groove, and the slider 3-4 can move in a single degree of freedom along the arrangement direction of the guide rail 3-3; The main board 3-2-4 of the limiting plate is attached to the limiting plate assembly surface 3-1-8, and screws are passed through the counterbore 3-2-5 for the limiting plate assembly and screwed into the limiting plate fixing threaded hole 3-1-9 to fix the limiting plate 3-2 to the base 3-1; The mover frame mounting plate 2-1-7 is attached to the slider 3-4, and screws are passed through the counterbore 2-1-8 for the mover frame assembly and screwed into the threaded hole of the slider 3-4 to fixedly connect the mover frame 2-1 and the slider 3-4; The limiting plate 3-2 limits the slider to the right to prevent it from sliding out of the guide rail 3-3. When the slider 3-4 moves to the left extreme position, the semi-circular boss 2-1-6 will abut against the magnet unit 1-3 to limit it to the left;

[0037] In a specific embodiment of the present invention, the arc-shaped groove 3-1-4 on the base side plate is in contact and cooperation with the magnet unit 1-3, and screws are passed through the magnet assembly counterbore 3-1-10 and screwed into the threaded hole 1-4 of the magnet unit to fix the magnet unit 1-3 on the magnet unit mounting plate 3-1-2; The base side plate 3-1-3 is vertically arranged on the base bottom plate 3-1-1 for the encapsulation of the actuator, and the base mounting hole 3-1-7 is used for the fixation of the base 3-1; The two arc-shaped bosses 3-2-3 on the limiting plate are symmetrically arranged on both sides of the top of the main board 3-2-4 of the limiting plate, and the radian of the arc-shaped boss 3-2-3 of the limiting plate matches the lower end of the end plate 2-1-5 of the mover frame; An avoidance groove 3-2-1 is provided between the two arc-shaped bosses 3-2-3 on the limiting plate; The avoidance groove 3-2-1 and the arc-shaped boss 3-2-3 on the limiting plate are provided to prevent interference between the mover frame and the limiting plate 3-2 when the mover frame moves with the slider 3-4; The chamfer 3-1-5 on the base side plate and the chamfer 3-2-2 on the limiting plate are provided to remove burrs.

[0038] In the present invention, the working principle of the butterfly-type electromagnetic-assisted precision piezoelectric inertial actuator is as shown in Figure 8As shown, it is stipulated that the rightward movement is the positive direction. When driving forward, a reverse direct current is applied to the electromagnetic driving component, and its current direction is as Figure 8 (a). According to Faraday's law of electromagnetic induction, the force conditions of the coil unit and the magnet unit can be known. Since the magnet unit is fixed on the base, the leftward force F m it receives will be offset by the reaction force of the bottom frame, and the coil unit will receive a rightward force F c , and drive the slider to have a tendency to move to the right; in the piezoelectric driving component, the contact surface between the piezoelectric sheet and the side arm of the mover frame is grounded at 0 potential, and the polarization directions of piezoelectric sheet I, piezoelectric sheet II, piezoelectric sheet III, and piezoelectric sheet IV are given in Figure 8 (a); at this time, a sawtooth wave with a duty cycle of 0% is applied to the opposite surface of the contact surface between piezoelectric sheet I, piezoelectric sheet II, piezoelectric sheet III, and piezoelectric sheet IV and the side arm of the mover frame. Among the 4 piezoelectric sheets, the surface in contact with the frame side arm is grounded, and the surface not in contact with the frame side arm is input in parallel and then a sawtooth wave signal is applied. When the voltage rises rapidly, the 4 piezoelectric sheets drive the side arm of the mover frame to quickly change from bending to the right to bending to the left, and the reaction force F P1 generated by the piezoelectric sheets driving the side arm of the mover frame to swing quickly will act on the slider, and the direction of the force is to the right at this time; when the voltage drops slowly, the 4 piezoelectric sheets drive the side arm of the mover frame to slowly change from leftward deformation to rightward deformation, and the reaction force F p2 generated by the piezoelectric sheets driving the side arm of the mover frame to swing quickly will act on the slider, and the direction of the force is to the left at this time; due to the difference in the asymmetric duty cycle change of the voltage, the inertial force F P1 will be greater than F P2 . The friction force between the slider and the guide rail is calibrated with F f . When the voltage rises rapidly, the resultant force F T received by the slider = F c +F P1 -F f ; when the voltage drops slowly, the resultant force received by the slider is F T = F c -F P2 -F f . By controlling the electrical signals between the electromagnetic driving component and the piezoelectric driving component, the forward driving of the composite positioning table can be realized, and two modes can be executed, namely the fast driving mode and the precision positioning mode; when executing the fast driving mode, the control electrical signal makes the resultant force received by the slider always greater than 0, and the electromagnetic driving component applies a large DC negative voltage so that the slider obtains a large resultant force F TWhen the precision positioning mode is executed, the electric signal of the electromagnetic drive component is controlled so that the resultant force on the slider is 0 when the voltage of the piezoelectric drive component slowly decreases, so as to suppress the displacement retraction generated when the piezoelectric drive component independently displaces during this stage, and a periodic sawtooth wave is applied to the piezoelectric drive to achieve micro-feed. In the present invention, one cycle of the sawtooth wave consists of two time periods, namely the voltage rising section or the voltage falling section. A duty cycle of 0% means that in one cycle of the sawtooth wave, the duration of the voltage rising section accounts for 0% of the cycle time; a duty cycle of 100% means that in one cycle of the sawtooth wave, the duration of the voltage rising section accounts for 100% of the cycle time. Among them, the final voltage of the voltage rising section (falling section) is the initial voltage of the voltage falling section (rising section), the voltage rising rate of the voltage rising section is constant, and the voltage decreasing rate of the voltage falling section is also constant.

[0039] The reverse working principle is as Figure 8 shown in b. A positive direct current is applied to the electromagnetic drive component. From the force analysis, it can be seen that at this time, the coil unit is subjected to a force F c to the left and drives the slider to have a tendency to move to the left. The contact surface between the piezoelectric sheet and the side arm of the mover frame in the piezoelectric drive component is grounded at 0 potential. A sawtooth wave voltage signal with a duty cycle of 100% is applied to the opposite surfaces of the contact surfaces between piezoelectric sheet I, piezoelectric sheet II, piezoelectric sheet III, and piezoelectric sheet IV and the side arm of the mover frame. When the voltage slowly rises, the resultant force on the slider is F T = F c - F P2 - F f . When the voltage rapidly decreases, the resultant force on the slider is F T = F c + F P1 - F f . Among them, due to the application of the asymmetric excitation signal, there is F p1 > F p2 ; similar to the forward working principle, two working modes of fast driving and precision positioning can also be realized during reverse driving.

[0040] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. For those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A butterfly-shaped electromagnetic-assisted precision piezoelectric inertial actuator, Characterized in that, It includes an electromagnetic drive assembly (1), a piezoelectric drive assembly (2), and a base assembly (3); The electromagnetic drive assembly includes a coaxially arranged coil unit (1-1) and a magnet unit (1-3). The coil unit (1-1) is sleeved in the magnet unit (1-3), and there is a clearance fit between the two. Among them, the magnet unit is fixedly connected to the base assembly, and the coil unit is fixedly connected to the piezoelectric drive assembly; The piezoelectric drive assembly (2) includes a mover frame (2-1) and four piezoelectric sheets; the mover frame (2-1) includes a mover frame end plate (2-1-5), two mover frame side arms (2-1-1) arranged on both sides of the mover frame end plate (2-1-5), a semi-circular boss (2-1-6) arranged at the upper end of the mover frame end plate (2-1-5), and a mover frame mounting plate (2-1-7) arranged at the lower end of the mover frame end plate (2-1-5); One piezoelectric sheet is fixed on both the upper and lower surfaces of the mover frame side arm (2-1-1), and the polarization directions of the piezoelectric sheets on the upper and lower surfaces are different, and the polarization directions of the piezoelectric sheets on the two mover frame side arms (2-1-1) in the same direction are the same; the mover frame end plate (2-1-5) is used to abut against the coil unit (1-1), and the coil unit (1-1) is fixedly arranged on the semi-circular boss (2-1-6); the base assembly (3) includes a base (3-1), a limit plate (3-2), a guide rail (3-3) and a slider (3-4); the base (3-1) includes a base bottom plate (3-1-1) and a magnet unit mounting plate (3-1-2); the magnet unit mounting plate (3-1-2) is vertically arranged at one end of the base bottom plate (3-1-1); a limit plate (3-2) is arranged at the other end of the base bottom plate (3-1-1); the guide rail (3-3) is fixed on the base bottom plate (3-1-1), and the direction of the guide rail (3-3) is perpendicular to the magnet unit mounting plate (3-1-2); the slider (3-4) is slidably arranged on the guide rail (3-3), and the upper surface of the slider (3-4) is fixedly connected to the mover frame mounting plate (2-1-7).

2. The butterfly-shaped electromagnetic-assisted precision piezoelectric inertial actuator according to claim 1, Characterized in that, An inertial block is fixed to one end of each of the four piezoelectric sheets away from the mover frame end plate (2-1-5).

3. The butterfly-shaped electromagnetic-assisted precision piezoelectric inertial actuator according to claim 1, Characterized in that, The base (3-1) further includes two base side plates (3-1-3), and the two base side plates (3-1-3) are respectively vertically arranged on the base bottom plate (3-1-1).

4. The butterfly-shaped electromagnetic-assisted precision piezoelectric inertial actuator according to claim 1, Characterized in that, The limiting plate (3-2) has a concave structure. The limiting plate (3-2) includes a limiting plate main board (3-2-4) and two limiting plate arc-shaped bosses (3-2-3). The two limiting plate arc-shaped bosses (3-2-3) are symmetrically arranged on both sides of the top of the limiting plate main board (3-2-4). The radian of the limiting plate arc-shaped boss (3-2-3) matches the lower end of the mover frame end plate (2-1-5). An avoidance groove (3-2-1) is formed between the two limiting plate arc-shaped bosses (3-2-3). The avoidance groove (3-2-1) is used to prevent interference between the mover frame and the limiting plate (3-2) when the mover frame moves with the slider (3-4).

5. The butterfly electromagnetic-assisted precision piezoelectric inertial actuator according to claim 1, characterized in that, the bending direction of the frame side arm (2-3-3) is opposite to the direction of the reaction force received by the slider.

6. A driving method of the butterfly electromagnetic-assisted precision piezoelectric inertial actuator according to claim 1, characterized in that: when moving to the right is specified as the positive direction, applying a positive voltage is defined as applying a positive direct current, and applying a negative voltage is defined as applying a reverse direct current; During forward driving, a reverse direct current is applied to the electromagnetic driving component; since the magnet unit is fixed on the base, the leftward force F it receives m will be offset by the reaction force of the bottom frame, and the coil unit will receive a rightward force F c , and drive the slider to have a tendency to move to the right; the contact surface between the piezoelectric sheet and the side arm of the mover frame in the piezoelectric driving component is grounded at 0 potential. At this time, a sawtooth wave with a duty cycle of 0% is applied to the surfaces of the four piezoelectric sheets that are not in contact with the frame side arm. Among them, the surfaces of the 4 piezoelectric sheets in contact with the frame side arm are grounded, and the surfaces not in contact with the frame side arm are input in parallel and then a sawtooth wave signal is applied; when the voltage rises rapidly, the 4 piezoelectric sheets drive the side arm of the mover frame to quickly change from bending to the right to bending to the left, and the reaction force F generated by the piezoelectric sheet driving the side arm of the mover frame to swing rapidly P1 will act on the slider, and at this time the reaction force F P1 is in the right direction; when the voltage drops slowly, the 4 piezoelectric sheets drive the side arm of the mover frame to slowly change from deforming to the left to deforming to the right, and the reaction force F generated by the piezoelectric sheet driving the side arm of the mover frame to swing rapidly P2 will act on the slider, and at this time the reaction force F P2 is in the left direction; due to the difference in the asymmetric duty cycle change of the voltage, the inertial force F P1 will be greater than F P2 ; the friction force between the slider and the guide rail is calibrated with F f . When the voltage rises rapidly, the resultant force F T received by the slider = F c + F P1 - F f ; when the voltage drops slowly, the resultant force received by the slider is F T = F c - F P2 - F f ; by controlling the electrical signals between the electromagnetic driving component and the piezoelectric driving component, the forward driving of the composite positioning table is realized, and it can execute two modes, namely the fast driving mode and the precision positioning mode; when executing the fast driving mode, the control electrical signal makes the resultant force received by the slider always greater than 0, and the electromagnetic driving component applies a large DC negative voltage so that the slider obtains a large resultant force F T ; when executing the precision positioning mode, the electrical signal of the electromagnetic driving component is controlled so that the resultant force received by the slider is 0 when the voltage of the piezoelectric driving component drops slowly, in order to suppress the displacement regression generated during the independent displacement of the piezoelectric driving component in this stage, and a periodic sawtooth wave is applied to the piezoelectric driving to achieve micro-feeding; When driving in reverse, a positive direct current is applied to the electromagnetic drive assembly. At this time, the coil unit is subjected to a force F to the left. c , and it drives the slider to have a tendency to move to the left; the contact surface between the piezoelectric sheet and the side arm of the mover frame in the piezoelectric drive assembly is grounded at 0 potential, and a sawtooth voltage signal with a duty cycle of 100% is applied to the surfaces of the four piezoelectric sheets that are not in contact with the frame side arm. When the voltage slowly rises, the resultant force on the slider is F T = F c - F P2 - F f , when the voltage rapidly decreases, the resultant force on the slider is F T = F c + F P1 - F f , where, due to the application of the asymmetric excitation signal, there is F P1 > F P2 ; Similar to the forward working principle, two working modes of fast driving and precise positioning can also be achieved when driving in reverse.

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