Electromagnetic-Assisted Piezoelectric Precision Inertial Actuator and Driving Method

Abstract

The present invention discloses an electromagnetic-assisted piezoelectric sheet-type precision 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 magnet unit in the electromagnetic driving component serves as the mover to avoid the influence of the leads of the electromagnetic driving component on the platform positioning accuracy. The piezoelectric driving component uses piezoelectric sheets 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 displacement retraction movement of the piezoelectric inertial driver is suppressed by electromagnetic force assistance, and on the other hand, the overall comprehensive output performance of the whole machine is improved by the combination of the 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.

Description

Technical Field

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

[0002] Ultra-precision driving and positioning technology plays an increasingly important role in the field of ultra-precision engineering technology. Compared with traditional driving technologies, piezoelectric driving technology has high resolution, fast response, and can be applied to extreme working conditions such as vacuum and ultra-low temperature. By combining electrical signal control, nanometer-level positioning accuracy can be achieved, and it has been widely used in fields such as ultra-precision machining, aerospace, precision optical instruments, and chip manufacturing.

[0003] When a piezoelectric element is driven based on the inverse piezoelectric effect, its deformation amount is extremely limited, with a maximum of only about 2% of its own length. Through mechanical structure design, the tiny vibration of the piezoelectric element can be converted into long-stroke displacement. This step-type piezoelectric actuator can achieve long-stroke high-precision positioning across scales. Based on its driving principle, it can be divided into piezoelectric ultrasonic actuators, piezoelectric inchworm actuators, and piezoelectric inertial actuators. Among them, the piezoelectric inertial actuator has a simple structure and can achieve long-stroke high-precision positioning with only one set of excitation sources. The other two types of piezoelectric actuators require at least two or more piezoelectric elements for coupled excitation. However, its load capacity is weak. In addition, when the inertial force generated by the mover due to its own movement speed and mass is not sufficient to overcome the reverse driving force in the "slip stage", displacement retraction movement will occur, deteriorating the driving speed and also exacerbating wear. This problem will be more severe under thrust load conditions. Summary of the Invention

[0004] Aiming at the technical problems of low precision of traditional electromagnetic driving, high precision of piezoelectric inertial driving but with displacement retraction problems, and difficulty in achieving high-speed driving for piezoelectric inertial actuators based on the principle of inertial impact, the present invention proposes an electromagnetic-assisted piezoelectric sheet-type precision inertial actuator and a driving method thereof.

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

[0006] The present invention provides an electromagnetic-assisted piezoelectric sheet-type precision inertial actuator, including an electromagnetic driving component, a piezoelectric driving component, and a bottom base;

[0007] The bottom base includes an L-shaped bottom frame, a slider, and a guide rail; the bottom frame is an L-shaped structure composed of a vertically arranged bottom frame side plate and a horizontally arranged bottom frame bottom plate; the slider is slidably arranged on the guide rail; the guide rail is fixed on the bottom frame bottom plate;

[0008] The piezoelectric drive assembly includes a piezoelectric sheet mounting frame and four piezoelectric sheets arranged on the piezoelectric sheet mounting frame; the piezoelectric sheet mounting frame includes a columnar main body of the frame, two frame side arms arranged on both sides of the columnar main body of the frame, and a bottom mounting boss; one piezoelectric sheet is fixed on each of the upper and lower surfaces of the frame side arms, 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 frame side arms in the same direction are the same, and the bending of the frame side arms is controlled by an electrical signal; the piezoelectric drive assembly is mounted on the slider through the bottom mounting boss;

[0009] The electromagnetic drive assembly includes a coil unit and a magnet unit, the axes of which are on the same straight line and can produce relative displacement in the transverse direction; the coil unit is fixedly connected to the bottom frame side plate, and the magnet unit is fixedly connected to the piezoelectric drive assembly.

[0010] According to a preferred embodiment of the present invention, the bottom base further includes a slider limit plate and a stop boss; the slider limit plate is arranged on the bottom frame bottom plate and abuts against one end of the guide rail; the stop boss is arranged on the side surface of the bottom frame bottom plate and abuts against the other end of the guide rail.

[0011] According to a preferred embodiment of the present invention, a countersunk hole for frame fixing is provided on the bottom mounting boss, and the countersunk hole for frame fixing is used to mount the piezoelectric sheet mounting frame on the bottom base.

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

[0013] 1) The bottom frame bottom plate is fixed to the optical vibration isolation platform, and the driving target object is fixed on the piezoelectric sheet mounting frame;

[0014] 2) It is stipulated that the rightward movement is the positive direction; when driving in the positive direction, a positive direct current is applied to the electromagnetic drive assembly; since the coil unit is fixed on the bottom frame, the leftward force F C will be offset by the reaction force of the bottom frame, and the magnet unit will receive a rightward force F m , and drive the slider to have a tendency to move to the right; the contact surface between the piezoelectric sheet and the frame side arm in the piezoelectric drive assembly is grounded to 0 volts; at this time, a sawtooth wave with a duty cycle of 0% is applied to the non-contact surfaces of the four piezoelectric sheets and the frame side arm, and the surfaces of the 4 piezoelectric sheets that are in contact with the frame side arm are grounded, and the surfaces that are not in contact with the frame side arm are input in parallel and then applied with a sawtooth wave signal; when the voltage rises rapidly, the 4 piezoelectric sheets drive the frame side arm to quickly change from bending to the right to bending to the left, and the reaction force F P1 generated by the piezoelectric sheet driving the frame side arm to swing quickly will act on the slider, and at this time the reaction force F P1The direction is to the right; when the voltage slowly decreases, the four piezoelectric sheets drive the side arms of the frame to slowly change from leftward deformation to rightward deformation, and the reaction force F generated by the rapid swing of the piezoelectric sheets driving the side arms of the frame p2 will act on the slider, and at this time the reaction force F p2 is in the leftward 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 frictional force between the slider and the guide rail with F f When the voltage rapidly increases, the resultant force F T received by the slider = F m + F P1 - F f ; when the voltage slowly decreases, the resultant force received by the slider is F T = F m - F P2 - F f ; by controlling the electrical signal between the electromagnetic drive component and the piezoelectric drive component, the forward drive of the composite positioning table can be 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 component applies a large DC 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 component is controlled so that the resultant force received by the slider is 0 when the voltage of the piezoelectric drive component slowly decreases, in order to suppress the displacement regression 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;

[0015] During reverse drive, a reverse direct current is applied to the electromagnetic drive component. At this time, the magnet unit receives a force F m 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 frame in the piezoelectric drive component is grounded at 0 potential, and a 100% sawtooth wave voltage signal is applied to the non-contact surfaces of the four piezoelectric sheets and the side arm of the frame. When the voltage slowly increases, the resultant force received by the slider is F T = F m - F P2 - F f ; when the voltage rapidly decreases, the resultant force received by the slider is F T = F m + F P1 - F f , where, due to the application of the asymmetric excitation signal, there is F p1 > F p2 ; the same as the forward working principle, fast drive and precision positioning two working modes can also be realized during reverse drive.

[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 through the combination of electromagnetic and piezoelectric drive sources. 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 have good wear resistance and service life. Through the input electrical signal control of the electromagnetic drive component and the piezoelectric drive component, two working modes of fast driving and precise positioning can be realized.

[0019] In the electromagnetic drive component of the present invention, the magnet unit is used as the mover to avoid the influence of the lead wire of the electromagnetic drive component on the platform positioning accuracy. The piezoelectric drive component selects piezoelectric sheets for driving, which has the advantage of low cost. Brief Description of the Drawings

[0020] Figure 1 It is the overall schematic diagram of the electromagnetic-assisted high-speed inertial micro-stage based on piezoelectric stack;

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

[0022] Figure 3 It is the structural schematic diagram of the piezoelectric drive component 2;

[0023] Figure 4 It is the structural schematic diagram of the piezoelectric sheet mounting frame;

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

[0025] Figure 6 It is the structural schematic diagram of the bottom frame;

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

[0027] Figure 8 It is the working principle of the magnetic induction type stacked piezoelectric inertial composite positioning stage.

[0028] In the figure: electromagnetic drive assembly 1, piezoelectric drive assembly 2, bottom base 3, coil unit 1-1, coil unit threaded hole 1-2, magnet unit 1-3, magnet unit threaded hole 1-4, piezoelectric sheet I 2-1, piezoelectric sheet II 2-2, piezoelectric sheet mounting frame 2-3, piezoelectric sheet III 2-4, piezoelectric sheet IV 2-5, machining avoidance groove 2-3-1 on the frame, columnar main body 2-3-2 of the frame, side arm 2-3-3 of the frame, counterbore hole 2-3-4 for frame fixing, counterbore hole 2-3-5 for frame mounting, drive target mounting threaded hole 2-3-6, frame mounting boss 2-3-7, bottom mounting boss 2-3-8, bottom frame 3-1, slider 3-2, guide rail 3-3, limit stop 3-4, side plate 3-1-1 of the bottom frame, coil unit mounting groove 3-1-2, slider limit plate 3-1-3, bottom plate 3-1-4 of the bottom frame, threaded hole 3-1-5 for guide rail mounting, chamfer 3-1-6 of the bottom plate of the bottom frame, counterbore hole 3-1-7 for bottom frame mounting, limit stop mounting groove 3-1-8, threaded hole 3-1-9 for limit stop mounting, chamfer 3-1-10 of the side plate of the bottom frame, counterbore hole 3-1-11 for coil unit mounting, wire arrangement hole 3-1-12, stop boss 3-4-1, fixing boss 3-4-2, counterbore hole 3-4-3 for limit block mounting. Detailed implementation mode

[0029] The present invention will be further described and explained below in conjunction with the detailed implementation mode. The described embodiments are only demonstrations of the disclosed content and do not delimit the scope of limitation. Without conflict, the technical features of each implementation mode in the present invention can be combined accordingly.

[0030] The overall schematic diagram of the electromagnetic-assisted piezoelectric sheet type precision inertial actuator designed by the present invention is as Figure 1 shown, mainly including an electromagnetic drive assembly 1, a piezoelectric drive assembly 2, and a bottom base 3. The bottom base 3 includes an L-shaped bottom frame 3-1, a slider 3-2, and a guide rail 3-3. The bottom frame 3-1 is an L-shaped structure composed of a vertically arranged side plate 3-1-1 of the bottom frame and a horizontally arranged bottom plate 3-1-4 of the bottom frame. The slider 3-2 is slidably arranged on the guide rail 3-3. The guide rail 3-3 is fixed on the bottom plate 3-1-4 of the bottom frame.

[0031] The piezoelectric drive assembly 2 includes a piezoelectric sheet mounting frame 2-3 and four piezoelectric sheets arranged on the piezoelectric sheet mounting frame 2-3; the piezoelectric sheet mounting frame 2-3 includes a columnar main body 2-3-2 of the frame, two frame side arms 2-3-3 arranged on both sides of the columnar main body 2-3-2 of the frame, and a bottom mounting boss 2-3-8; one piezoelectric sheet is fixed on each of the upper and lower surfaces of the frame side arm 2-3-3, 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 frame side arms 2-3-3 in the same direction are the same, and the bending of the frame side arm 2-3-3 is controlled by an electrical signal; the piezoelectric drive assembly 2 is mounted on the slider 3-2 through the bottom mounting boss 2-3-8;

[0032] The electromagnetic drive assembly 1 includes a coil unit 1-1 and a magnet unit 1-3; the coil unit 1-1 is fixedly connected to the bottom frame side plate 3-1-1, and the magnet unit 1-3 is fixedly connected to the piezoelectric drive assembly 2.

[0033] In a specific embodiment of the present invention, the electromagnetic drive assembly 1 is as Figure 2 shown, and 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 coil unit 1-1 is fixedly connected to the bottom base 3 by screwing a screw into the coil unit threaded hole 1-2, and the magnet unit 1-3 is fixedly connected to the piezoelectric drive assembly 2 by screwing a screw into the magnet unit threaded hole 1-4; the piezoelectric drive assembly 2 is connected to the bottom base 3 by screws.

[0034] In a specific embodiment of the present invention, the piezoelectric drive assembly 2 is as Figure 3 shown, and it is composed of a piezoelectric sheet I 2-1, a piezoelectric sheet II 2-2, a piezoelectric sheet mounting frame 2-3, a piezoelectric sheet III 2-4, and a piezoelectric sheet IV 2-5; the piezoelectric sheet mounting frame 2-3 is as Figure 4As shown in the figure, it is provided with a frame machining avoidance groove 2-3-1, a frame columnar main body 2-3-2, a frame side arm 2-3-3, and a frame fixing countersunk hole 2-3-4; a frame mounting countersunk hole 2-3-5, a driving target mounting threaded hole 2-3-6, a frame mounting boss 2-3-7, and a bottom mounting boss 2-3-8; a group of frame side arms 2-3-3 are distributed on both sides of the frame columnar main body 2-3-2, and the piezoelectric sheets I 2-1, piezoelectric sheets II 2-2, piezoelectric sheets III 2-4, and piezoelectric sheets IV 2-5 are fixed on the frame side arms 2-3-3 in pairs by adhesive connection; the piezoelectric sheets I 2-1 and piezoelectric sheets IV 2-5 have the same polarization direction; the piezoelectric sheets II 2-2 and piezoelectric sheets III 2-4 have the same polarization direction, and both are opposite to the polarization directions of the piezoelectric sheets I 2-1 and piezoelectric sheets IV 2-5; the deformation of the frame side arms 2-3-3 can be controlled through an electrical signal; the opening of the frame machining avoidance groove 2-3-1 is for the machining of the frame fixing countersunk hole 2-3-4, and the screw passes through the frame fixing countersunk hole 2-3-4 to fix the piezoelectric drive assembly 2 on the bottom base 3, where the bottom mounting boss 2-3-8 is in contact with the bottom base 3; the piezoelectric sheet mounting frame 2-3 and the magnet unit 1-3 are fixedly connected by a screw passing through the frame mounting countersunk hole 2-3-5 and screwing into the magnet unit threaded hole 1-4; the actuator drives the target object and can be fixed by screwing into the driving target mounting threaded hole 2-3-6 and fitting on the frame mounting boss 2-3-7;

[0035] In a specific embodiment of the present invention, the bottom base is as Figure 5 shown, and it is composed of a bottom frame 3-1, a slider 3-2, a guide rail 3-3, and a limit stop 3-4; the bottom frame 3-1 is as Figure 6 shown, and it includes a bottom frame side plate 3-1-1, a coil unit mounting groove 3-1-2, a slider limit plate 3-1-3, a bottom frame bottom plate 3-1-4, a guide rail mounting threaded hole 3-1-5, a bottom frame bottom plate chamfer 3-1-6, a bottom frame mounting countersunk hole 3-1-7, a limit stop mounting groove 3-1-8, a limit stop mounting threaded hole 3-1-9, a bottom frame side plate chamfer 3-1-10, a coil unit mounting countersunk hole 3-1-11, and a wire arranging hole 3-1-12; the limit stop 3-4 is as Figure 7As shown in the figure, it is provided with a stop boss 3-4-1, a fixed boss 3-4-2 and a counterbore for limit block installation 3-4-3; the coil unit 1-1 is installed within the coil unit installation groove 3-1-2, and the screw passes through the coil unit installation counterbore 3-1-11 and is screwed into the coil unit threaded hole 1-2 to fix the coil unit 1-1 on the bottom frame side plate 3-1-1; the guide rail 3-3 is fixed on the bottom frame bottom plate 3-1-4 by using a screw passing through the guide rail 3-3 and being screwed into the guide rail installation threaded hole 3-1-5. The slider 3-2 and the guide rail 3-3 are connected by a groove fit to achieve single-degree-of-freedom sliding in the left-right direction. The slider limit plate 3-1-3 limits the left movement of the slider 3-2; the chamfers 3-1-6 of the bottom frame bottom plate and 3-1-10 of the bottom frame side plate are provided for the beautification of the configuration appearance and the removal of burrs, and the bottom frame installation counterbore 3-1-7 is used for the overall fixation of the actuator; the fixed boss 3-4-2 is inserted into the limit block installation groove 3-1-8, and the two are in transition fit. The screw passes through the counterbore for limit block installation 3-4-3 and is screwed into the limit block installation threaded hole 3-1-9 to fix the limit block 3-4 on the bottom frame 3-1; the wire arrangement hole 3-1-12 is used to discharge the wires of the coil unit 1-1; the stop boss 3-4-1 is used to limit the right movement of the slider 3-2.

[0036] The working principle of the electromagnetic-assisted piezoelectric sheet type precision inertial actuator of the present invention is as Figure 8 shown, where the rightward movement is specified as the positive direction. During forward driving, a positive direct current is applied to the electromagnetic driving component, and its current direction is as Figure 8 (a) shown. According to Faraday's law of electromagnetic induction, the force conditions of the coil unit and the magnet unit can be known. Since the coil unit is fixed on the bottom frame, the leftward force F C received by it will be offset by the reaction force of the bottom frame, and the magnet unit will receive a rightward force F m , and drive the slider to have a tendency to move rightward; the contact surface between the piezoelectric sheet and the frame side arm in the piezoelectric driving component 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 frame side arm. Among them, the surface of the 4 piezoelectric sheets that fits with the frame side arm is grounded, and the surface that does not fit with the frame side arm is input in parallel and then applied with a sawtooth wave signal. When the voltage rises rapidly, the 4 piezoelectric sheets drive the frame side arm to quickly change from bending to the right to bending to the left, and the reaction force F P1 generated by the rapid swing of the piezoelectric sheet driving the frame side arm will act on the slider, and the direction of the force is rightward at this time; when the voltage drops slowly, the 4 piezoelectric sheets drive the frame side arm to slowly change from left deformation to right deformation, and the reaction force F p2It will act on the slider, and at this time the direction of the force is to the left; due to the difference in the asymmetric duty cycle change of the voltage, the inertial force F will be caused. P1 is 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 m + F P1 - F f ; when the voltage drops slowly, the resultant force received by the slider is F T = F m - F P2 - F f . By controlling the electrical signal between the electromagnetic drive component and the piezoelectric drive component, the forward drive of the composite positioning table can be 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 component applies a large DC voltage so that the slider obtains a large resultant force F T ; when the precision positioning mode is executed, the control electrical signal of the electromagnetic drive component is such that the resultant force received by the slider is 0 when the voltage of the piezoelectric drive component drops slowly, so as to suppress the displacement back-off generated when the piezoelectric drive component displaces independently in 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.

[0037] The reverse working principle is as shown in Figure 8 (b). Apply a reverse direct current to the electromagnetic drive component. From the force analysis, it can be seen that at this time the magnet unit receives a force F m 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 frame in the piezoelectric drive component is grounded at 0 potential. Apply a 100% sawtooth wave voltage signal 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 frame. When the voltage rises slowly, the resultant force received by the slider is F T = F m - F P2 - F f . When the voltage drops rapidly, the resultant force received by the slider is F T = F m + F P1 - Ff , 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.

[0038] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation to 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 modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. An electromagnetic-assisted piezoelectric sheet-type precision inertial actuator, characterized in that, it includes an electromagnetic drive assembly (1), a piezoelectric drive assembly (2) and a bottom base (3); The bottom base (3) includes an L-shaped bottom frame (3-1), a slider (3-2) and a guide rail (3-3); the bottom frame (3-1) is an L-shaped structure composed of a vertically arranged bottom frame side plate (3-1-1) and a horizontally arranged bottom frame bottom plate (3-1-4); the slider (3-2) is slidably arranged on the guide rail (3-3); the guide rail (3-3) is fixed on the bottom frame bottom plate (3-1-4); The piezoelectric drive assembly (2) includes a piezoelectric sheet mounting frame (2-3) and four piezoelectric sheets arranged on the piezoelectric sheet mounting frame (2-3); the piezoelectric sheet mounting frame (2-3) includes a columnar main body of the frame (2-3-2), two frame side arms (2-3-3) arranged on both sides of the columnar main body of the frame (2-3-2) and a bottom mounting boss (2-3-8); one piezoelectric sheet is fixed on both the upper and lower surfaces of the frame side arm (2-3-3) and the polarization directions of the piezoelectric sheets on the upper and lower surfaces are different, and the piezoelectric sheets in the same direction on the two frame side arms (2-3-3) have the same polarization direction, and the bending of the frame side arm (2-3-3) is controlled by an electric signal; the piezoelectric drive assembly (2) is mounted on the slider (3-2) through the bottom mounting boss (2-3-8); The electromagnetic drive assembly (1) includes a coil unit (1-1) and a magnet unit (1-3), the axes of the two are on the same straight line, and a relative displacement can be generated transversely; the coil unit (1-1) is fixedly connected to the bottom frame side plate (3-1-1), and the magnet unit (1-3) is fixedly connected to the piezoelectric drive assembly (2); The driving method of the electromagnetic-assisted piezoelectric sheet-type precision inertial actuator includes the following steps: 1) The bottom frame bottom plate is fixed to the optical vibration isolation platform, and the driving target object is fixed to the piezoelectric sheet mounting frame; 2) It is stipulated that the rightward movement is the positive direction; when driving forward, a positive direct current is applied to the electromagnetic drive assembly; since the coil unit is fixed on the bottom frame, the leftward force F it receives C will be offset by the reaction force of the bottom frame, and the magnet unit will receive a rightward force F m , 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 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 non-contact surfaces of the four piezoelectric sheets and the side arm of the frame. Among them, the surfaces of the 4 piezoelectric sheets that are in contact with the side arm of the frame are grounded, and the surfaces that are 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 frame to quickly change from bending to the right to bending to the left, and the reaction force F generated by the rapid swing of the piezoelectric sheet driving the side arm of the frame 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 frame to slowly change from deforming to the left to deforming to the right, and the reaction force F generated by the rapid swing of the piezoelectric sheet driving the side arm of the frame 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 ; 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 m +F P1 -F f ; when the voltage drops slowly, the resultant force received by the slider is F T = F m -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 can be realized, and it can execute two modes, namely the fast drive mode and the precision positioning mode; when executing the fast drive mode, the control electrical signal makes the resultant force received by the slider always greater than 0; when executing the precision positioning mode, 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 backlash 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; When driving in the reverse direction, a reverse direct current is applied to the electromagnetic drive assembly. At this time, the magnet unit is subjected to a force F to the left m , 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 frame in the piezoelectric drive assembly is grounded at 0 potential, and a 100% sawtooth voltage signal is applied to the non-contact surfaces of the four piezoelectric sheets and the side arm of the frame. When the voltage slowly rises, the resultant force on the slider is F T = F m - F P2 - F f , when the voltage rapidly decreases, the resultant force on the slider is F T = F m + 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.

2. The electromagnetic-assisted piezoelectric sheet-type precision inertial actuator according to claim 1, characterized in that, The bottom base (3) further includes a slider limit plate (3-1-3) and a stop boss (3-4-1); the slider limit plate (3-1-3) is arranged on the bottom frame bottom plate (3-1-4) and abuts against one end of the guide rail (3-3); the stop boss (3-4-1) is arranged on the side surface of the bottom frame bottom plate (3-1-4) and abuts against the other end of the guide rail (3-3).

3. The electromagnetic-assisted piezoelectric sheet-type precision 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.

4. The electromagnetic-assisted piezoelectric sheet-type precision inertial actuator according to claim 1, characterized in that, A frame fixing counterbore (2-3-4) is opened on the bottom mounting boss (2-3-8), and the frame fixing counterbore (2-3-4) is used to mount the piezoelectric sheet mounting frame (2-3) on the bottom base (3).

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