A magnetically induced stacked piezoelectric inertial composite positioning platform and driving method

Abstract

The present invention discloses a magnetically induced stacked piezoelectric inertial composite positioning platform and a driving method, which includes a stage, an electromagnetic driving component, a piezoelectric driving unit and a base unit; the electromagnetic driving component includes a coil unit and a magnet unit, a flexible mechanism is arranged in the piezoelectric driving component, and a piezoelectric stack is installed inside the flexible mechanism; when the piezoelectric stack is excited, the flexible mechanism can be deformed and drive the inertial block to produce horizontal displacement. The magnet unit of the present invention is used as a mover to avoid the influence of the lead wire of the electromagnetic driving unit on the positioning accuracy of the platform. On the one hand, the displacement and retreat movement of the piezoelectric driving unit is suppressed by electromagnetic force induction assistance, and on the other hand, the comprehensive output performance of the whole machine is improved by combining the two driving sources of electromagnetic and piezoelectric, which can effectively improve its thrust load, increase the driving speed, suppress displacement retreat and oscillation, and ensure that it has high-precision positioning.

Description

Technical Field

[0001] The invention belongs to the technical field of precision machinery and high-speed driving, and in particular relates to a magnetically induced stacked piezoelectric inertial composite positioning platform and a driving method. Background Art

[0002] High-precision positioning systems have been widely used in many fields, including ultra-precision manufacturing, biological manipulation, scanning probe microscopy, and semiconductor manufacturing. The above-mentioned high-end equipment engineering technology fields require high positioning accuracy while also requiring the system to have comprehensive performance such as compact structure, large travel displacement, high response speed, and ability to adapt to extreme environments. Piezoelectric materials can achieve nanometer-level resolution based on the inverse piezoelectric effect, and have the advantages of compact structure, no electromagnetic interference, and fast response, and are widely studied.

[0003] In order to overcome the micron-level limited stroke of piezoelectric elements, some stepping piezoelectric actuators have been developed based on the inverse piezoelectric effect, including traveling wave actuators, standing wave actuators, inchworm actuators, and inertial actuators. Traveling wave and standing wave actuators are usually used for high-speed and continuous motion, but the relatively weak resolution in low-speed positioning is still a problem that needs to be solved. The inchworm drive positioner can achieve large stroke motion under high output force, but its working principle is relatively complex because it usually requires at least three piezoelectric elements to achieve a drive of one degree of freedom. Among them, in addition to the typical advantages of piezoelectric actuators, the piezoelectric drive unit also has the advantages of simple structure, compactness, large stroke, high precision, and long-term continuous operation, but its load capacity is weak. Due to its working principle based on friction difference drive, friction and wear problems have to be considered in actual engineering applications. In addition, when the inertial force generated by the mover due to its own movement speed and mass is not enough to overcome the reverse driving force of the "slip stage", it will cause the displacement retraction motion, which will deteriorate the drive speed and aggravate the wear. This problem will be more serious under thrust load conditions. Summary of the invention

[0004] The present invention aims to solve the technical problems that traditional electromagnetic drive has low precision, piezoelectric inertial drive has high precision but has displacement regression and serious friction and wear problems, and piezoelectric drive units based on the inertial impact principle are difficult to achieve high-speed drive. A magnetically induced stacked piezoelectric inertial composite positioning table and a driving method are proposed.

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

[0006] The present invention provides a magnetic induction stacked piezoelectric inertial composite positioning platform, which comprises: a stage for carrying a driving target, an electromagnetic driving component, a piezoelectric driving unit and a base unit;

[0007] The base unit is an L-shaped structure consisting of a vertical surface and a horizontal surface, and the electromagnetic drive assembly includes a coaxially arranged coil unit and a magnet unit, the coil unit is sleeved inside the magnet unit, a gap is set between the two, and the two can generate relative displacement along the axis direction, wherein the magnet unit is fixedly connected to the stage, and the coil unit is fixedly connected to the vertical surface of the base unit;

[0008] A guide rail and a slider that cooperates with the guide rail and can slide relative to the guide rail are arranged on the horizontal surface of the base unit; the piezoelectric drive unit includes an inertia block, a piezoelectric stack and a flexible mechanism; one end of the flexible mechanism is fixedly connected to the slider and the magnet unit, and the other end opposite thereto is provided with an inertia block, the flexible mechanism has a cavity inside and is installed with the piezoelectric stack; when the piezoelectric stack is excited, the flexible mechanism can be deformed and drive the inertia block to produce horizontal displacement.

[0009] According to a preferred embodiment of the present invention, the upper surface of the stage is a plane for carrying a driven target, and the lower surface of the stage is processed with an arc-shaped groove of the stage, and the inner wall of the arc-shaped groove of the stage is fitted and fixed to the upper surface of the magnet unit; the arc-shaped groove of the stage is closed at one end along the groove direction and open at the other end, and the open end faces the vertical surface of the base unit.

[0010] According to a preferred solution of the present invention, the inertia block is located between the flexible mechanism and the vertical surface of the base unit, and a rectangular avoidance groove is provided on the vertical surface of the base unit to avoid contact between the inertia block and the vertical surface of the base unit.

[0011] The present invention also provides a driving method for the magnetic induction stacked piezoelectric inertial composite positioning platform, which comprises the following steps:

[0012] 1) The lower surface of the base unit is in contact with and fixed to the optical vibration isolation platform, and the driving target object is set on the upper surface of the stage;

[0013] 2) The rightward movement is defined as the positive direction, the application of a positive voltage is defined as the application of positive direct current, and the application of a negative voltage is defined as the application of reverse direct current;

[0014] When driving in the forward direction, a positive direct current is applied to the electromagnetic drive unit. Since the coil unit is fixed on the vertical surface of the base unit, it is subjected to a leftward force F. C The reaction force of the base unit will be offset, and the magnet unit will be subjected to a force F to the right. m , and drives the slider to move to the right; at this time, the piezoelectric drive unit is fed with a sawtooth wave with a duty cycle of 0% to 10%; when the voltage increases rapidly, the piezoelectric stack quickly extends and drives the flexible mechanism to deform, and the inertial force F of the inertial block P1 will act on the slider, and the direction of the force is to the right; when the voltage is slowly reduced, the piezoelectric stack slowly contracts, and the inertial force F of the inertial blockp2 Will act on the slider, and the direction of the force is to the left; due to the difference in the asymmetric duty cycle of the voltage, the inertial force F P1 Greater than F P2 ; The friction between the slider and the guide rail is expressed as F f Calibration: When the voltage increases rapidly, the resultant force F on the slider is T =F m +F P1 -F f ; When the voltage decreases slowly, the resultant force on the slider is F T =F m -F P2 -F f ; The forward drive of the composite positioning stage can be realized by controlling the electrical signal between the electromagnetic drive unit and the piezoelectric drive unit, and two modes can be executed, namely, the fast drive mode and the precise positioning mode; when executing the fast drive mode, the electrical signal is controlled so that the resultant force on the slider is always greater than 0, and the electromagnetic drive unit applies a larger DC voltage so that the slider obtains a larger resultant force F T ; When executing the precision positioning mode, the electrical signal of the electromagnetic drive unit is controlled so that the resultant force on the slider is 0 when the voltage of the piezoelectric drive unit is slowly reduced, so as to suppress the displacement retreat caused by the independent displacement of the piezoelectric drive unit at this stage, and a periodic sawtooth wave is introduced into the piezoelectric drive to achieve micro-feeding;

[0015] When working in reverse, reverse DC is applied to the electromagnetic drive unit, and the magnet unit is subjected to a leftward force F. m , and drives the slider to move to the left; apply 90% to 100% sawtooth wave voltage signal to the piezoelectric drive unit. When the voltage increases slowly, the resultant force on the slider is F T =F m -F P2 -F f , when the voltage drops rapidly, the resultant force on the slider is F T =F m +F P1 -F f , where due to the application of asymmetric excitation signal, F p1 >F p2 ; The working principle is the same as that of the forward direction. In reverse driving, two working modes, fast driving and precise positioning, can also be achieved.

[0016] Compared with the prior art, the present invention combines an electromagnetic drive unit based on the voice coil motor drive principle with a piezoelectric drive unit based on the piezoelectric inertial drive principle. The magnet unit in the electromagnetic drive unit is used as a mover to avoid the influence of the electromagnetic drive unit lead wire on the platform positioning accuracy.

[0017] The present invention utilizes the characteristic that the piezoelectric driver is not susceptible to electromagnetic interference. On the one hand, it uses electromagnetic force induction to assist in suppressing the displacement and retraction movement of the piezoelectric drive unit. On the other hand, it improves the comprehensive output performance of the whole machine by combining the two driving sources of electromagnetic and piezoelectric. It can effectively increase its thrust load, increase the driving speed, suppress displacement and retraction, and oscillation, while ensuring high-precision positioning.

[0018] The present invention only has a pair of friction pairs of the guide rail and the slider. The lubrication treatment can ensure that the whole machine has good wear resistance and service life. Through the input electrical signal control of the electromagnetic drive unit and the piezoelectric drive unit, two working modes of rapid drive and precise positioning can be realized.

[0019] The present invention has great application prospects in the fields of active optics, super-resolution imaging sample movement, micro-nano assembly and manufacturing, integrated circuit manufacturing and detection, scanning electron microscope sample manipulation, large-scale electron beam direct writing, fiber and nano-CT, high-vacuum sample precision alignment and posture adjustment, nano-focusing and scanning, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an overall schematic diagram of the magnetically induced stacked piezoelectric inertial composite positioning platform;

[0021] Figure 2 This is the structural explosion diagram of the magnetically induced stacked piezoelectric inertial composite positioning platform;

[0022] Figure 3 Schematic diagram of the stage structure;

[0023] Figure 4 It is a schematic diagram of the structure of the electromagnetic drive unit;

[0024] Figure 5 Schematic diagram of the structure of the piezoelectric drive unit;

[0025] Figure 6 is a schematic diagram of the flexible mechanism;

[0026] Figure 7 Schematic diagram of the structure of the lower wedge-shaped gasket;

[0027] Figure 8 is a schematic diagram of the base unit structure;

[0028] Fig. 9 is a schematic diagram of the base structure;

[0029] Fig.10 Schematic diagram of the limiting plate structure;

[0030] Fig.11 This is the working principle diagram of the magnetically induced stacked piezoelectric inertial composite positioning table.

[0031] In the figure, the stage 1, the electromagnetic drive unit 2, the piezoelectric drive unit 3, the base unit 4, the stage surface 1-1, the magnet unit mounting countersunk hole 1-2, the stage outer end surface 1-3, the stage inner end surface 1-4, the stage side wall 1-5, the stage arc groove 1-6, the coil unit 2-1, the coil unit threaded hole 2-2, the magnet unit 2-3, the magnet unit threaded hole 2-4, the inertia block 3-1, the piezoelectric stack 3-2, the flexible mechanism 3-3, the lower wedge-shaped gasket 3-4, the upper wedge-shaped gasket 3-5, the flexible mechanism arc groove 3-3-1, the flexible mechanism connecting plate 3-3-2, the flexible mechanism connecting block 3-3-3, the flexible mechanism oblique side beam 3-3-4, the flexible mechanism side beam 3-3-5, the inertia block Linking plate 3-3-6, circular flexible hinge 3-3-7, bottom surface of flexible mechanism connecting plate 3-3-8, side surface of wedge-shaped gasket 3-4-1, wedge surface of wedge-shaped gasket 3-4-2, base 4-1, limit plate 4-2, guide rail 4-3, slider 4-4, base boss 4-1-1, circular groove 4-1-2, rectangular avoidance groove 4-1-3, wiring hole 4-1-4, base bottom plate 4-1-5, base side plate 4-1-6, bottom plate mounting countersunk hole 4-1-7, guide rail mounting threaded hole 4-1-8, limit plate mounting threaded hole 4-1-9, base chamfer 4-1-10, coil unit mounting countersunk hole 4-1-11, limit plate boss 4-2-2, limit plate mounting countersunk hole 4-2-1. DETAILED DESCRIPTION

[0032] The present invention is further described and illustrated below in conjunction with specific embodiments. The embodiments are merely exemplary of the present disclosure and do not define the scope of limitation. The technical features of each embodiment of the present invention may be combined accordingly without conflicting with each other.

[0033] The overall schematic diagram of the electromagnetic-assisted high-speed inertial micro-motion stage based on piezoelectric stack designed by the present invention is as follows: Figure 1 As shown, its structural explosion diagram is as follows Figure 2 As shown, it mainly includes a stage 1, an electromagnetic drive assembly 2, a piezoelectric drive unit 3 and a base unit 4;

[0034] The base unit is an L-shaped structure consisting of a vertical surface and a horizontal surface. The electromagnetic drive assembly includes a coaxially arranged coil unit 2-1 and a magnet unit 2-3. The coil unit 2-1 is sleeved inside the magnet unit 2-3. A gap is provided between the two. The two can generate relative displacement along the axis direction. The magnet unit is fixedly connected to the stage 1, and the coil unit is fixedly connected to the vertical surface of the base unit.

[0035] A guide rail 4-3 and a slider 4-4 that cooperates with the guide rail and can slide relative to the guide rail are arranged on the horizontal surface of the base unit; the piezoelectric drive unit 3 includes an inertia block 3-1, a piezoelectric stack 3-2 and a flexible mechanism 3-3; one end of the flexible mechanism is fixedly connected to the slider 4-4 and the magnet unit 2-3, and the other end opposite thereto is provided with an inertia block 3-1, and the flexible mechanism has a cavity inside and is installed with the piezoelectric stack 3-2; when the piezoelectric stack is excited, the flexible mechanism can be deformed and drive the inertia block to produce horizontal displacement.

[0036] In a specific embodiment of the present invention, the stage structure schematic diagram is as follows Figure 3 As shown, it mainly includes a loading surface 1-1, a magnet unit mounting countersunk hole 1-2, an outer end surface 1-3 of the loading platform, an inner end surface 1-4 of the loading platform, a side wall 1-5 of the loading platform, and an arc-shaped groove 1-6 of the loading platform; the schematic diagram of the electromagnetic drive unit structure is shown in Figure 4 As shown, it includes a coil unit 2-1, a coil unit threaded hole 2-2, a magnet unit 2-3, and a magnet unit threaded hole 2-4; the loading surface 1-1 is used to carry samples, a magnet unit mounting countersunk hole 1-2 is opened on the side of the outer end surface 1-3 of the loading platform, and the loading platform side wall 1-5 is used for the platform appearance packaging; the loading platform arc groove 1-6 and the loading platform inner end surface 1-4 are fitted with the outer surface of the magnet unit 2-3, and the screw passes through the magnet unit mounting countersunk hole 1-2 and is screwed into the magnet unit threaded hole 2-4; the coil unit 2-1 and the magnet unit 2-3 are clearance-matched and can move relatively. The coil unit 2-1 and the magnet unit 2-3 are a voice coil motor mechanism as a whole, and have good interchangeability for the voice coil motors produced on the market when applied to the micro-motion stage.

[0037] In a specific embodiment of the present invention, the structural schematic diagram of the piezoelectric drive unit is as follows: Figure 5 As shown, it includes an inertial block 3-1, a piezoelectric stack 3-2, a flexible mechanism 3-3, a lower wedge-shaped gasket 3-4, and an upper wedge-shaped gasket 3-5; the lower wedge-shaped gasket 3-4 and the upper wedge-shaped gasket 3-5 cooperate with each other through the wedge-shaped surfaces to press the piezoelectric stack 3-2 into the flexible mechanism 3-3, and the pre-pressure of the piezoelectric stack 3-2 subjected to the flexible mechanism 3-3 can be adjusted by adjusting the relative position between the lower wedge-shaped gasket 3-4 and the upper wedge-shaped gasket 3-5; after the pre-pressure adjustment is completed, vibration prevention can be performed by gluing, or only the friction between the wedge pieces can be used to prevent loosening. In order to ensure the reliability of the assembly, the latter should take a smaller value when designing the wedge piece angle.

[0038] The flexible mechanism 3-3 is provided with a flexible mechanism arc groove 3-3-1, a flexible mechanism connecting plate 3-3-2, a flexible mechanism connecting block 3-3-3, a flexible mechanism oblique side beam 3-3-4, a flexible mechanism side beam 3-3-5, an inertia block linking plate 3-3-6, a circular flexible hinge 3-3-7, and a flexible mechanism connecting plate bottom surface 3-3-8. The overall material of the flexible mechanism is a high-strength and low-density metal, such as AL7075; the inertia block 3-1 and the inertia block linking plate 3-3-6 are bonded to the flexible mechanism by gluing or welding. 3-3 is fixedly connected; the magnet unit 2-3 is assembled in the arc groove 3-3-1 of the flexible mechanism, and the magnet unit 2-3 is fixedly connected to the flexible mechanism 3-3 by gluing or welding; four flexible mechanism oblique side beams 3-3-4, two flexible mechanism side beams 3-3-5, flexible mechanism connection block 3-3-3 and inertia block link plate 3-3-6 form a polygonal mechanism, and eight circular flexible hinges 3-3-7 are provided at the connection of each unit; the bottom surface 3-3-8 of the flexible mechanism connection plate is fixedly connected to the base unit. The bottom surface of the flexible mechanism connection plate (3-3-2) is connected to the slider 4-2.

[0039] The lower wedge-shaped gasket 3-4 has the same structure as the upper wedge-shaped gasket 3-5. The structural schematic diagram of the lower wedge-shaped gasket 3-4 is shown in FIG. Figure 7 As shown, it includes a wedge-shaped gasket side surface 3-4-1 and a wedge-shaped gasket wedge surface 3-4-2, and the angle between the wedge surface of the lower wedge-shaped gasket and the upper wedge-shaped gasket and the vertical surface is an acute angle less than or equal to 15 degrees.

[0040] In the present invention, the movement directions of the inertial block, the slider and the magnet unit are parallel to each other and are all horizontally to the left or right; the vibration direction of the piezoelectric stack is perpendicular to the above movement directions.

[0041] In a specific embodiment, the base unit 4 is as follows Figure 8 As shown, it is composed of a base 4-1, a limit plate 4-2, a guide rail 4-3 and a slider 4-4; the base 4-1 is as shown Fig. 9As shown, it includes a base boss 4-1-1, a circular groove 4-1-2, a rectangular avoidance groove 4-1-3, a wiring hole 4-1-4, a base bottom plate 4-1-5, a base side plate 4-1-6, a bottom plate mounting countersunk hole 4-1-7, a guide rail mounting threaded hole 4-1-8, a limit plate mounting threaded hole 4-1-9, a base chamfer 4-1-10, and a coil unit mounting countersunk hole 4-1-11; the limit plate 4-2 is composed of a limit plate boss 4-2-2 and a limit plate mounting The guide rail 4-3 is fitted with the base bottom plate 4-1-5, and the screw passes through the guide rail 4-3 and is screwed into the guide rail mounting threaded hole 4-1-8 to fix the guide rail 4-3 on the base 4-1; the slider 4-4 is assembled on the guide rail 4-3 through the groove; the screw passes through the limit plate mounting countersunk hole 4-2-1 and is screwed into the limit plate mounting threaded hole 4-1-9 to fix the limit plate 4-2 on the base 4-1, and the limit plate boss 4-2- 2. The slider 4-4 is limited to the right to prevent it from sliding out of the guide rail 4-3; the end of the coil unit 2-1 is inserted into the circular groove 4-1-2, and the diameter difference between the two is 4mm, and space for wiring is reserved. The screw passes through the coil unit mounting countersunk hole 4-1-11 and is screwed into the coil unit threaded hole 2-2 to fix the coil unit 2-1 on the base 4-1; when the electromagnetic drive unit 2 is in the zero point state, the base boss 4-1-1 limits the movement of the stage 1 to the left, that is, the slider 4-4 is limited to the right; the rectangular avoidance groove 4-1-3 is opened to avoid motion interference between the piezoelectric drive unit 3 and the base 4-1, and the wiring hole 4-1-4 is opened to discharge the wires of the electromagnetic drive unit 2 and the piezoelectric drive unit 3; the base side panel 4-1-6 is used for the packaging of the platform, the bottom plate mounting countersunk hole 4-1-7 is opened to fix the entire platform, and the base chamfer 4-1-10 is opened to remove burrs and beautify the appearance of the platform.

[0042] The working principle of the magnetically induced stacked piezoelectric inertial composite positioning platform of the present invention is as follows: Fig.11 As shown in the figure, the rightward movement is defined as the positive direction. When driving in the positive direction, a positive direct current is supplied to the electromagnetic drive unit, and the current direction is as follows: Fig.11 As shown in (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 coil unit is fixed on the base, the leftward force F C The reaction force of the base will be offset, and the magnet unit will be subjected to a force F to the right. m , and drives the slider to move to the right; at this time, the piezoelectric drive unit can pass a sawtooth wave with a duty cycle of 0% to 10%. When the voltage increases rapidly, the piezoelectric stack quickly extends and drives the flexible mechanism to deform, and the inertial force F of the inertial block P1 will act on the slider, and the direction of the force is to the right; when the voltage is slowly reduced, the piezoelectric stack slowly contracts, and the inertial force F of the inertial blockp2 Will act on the slider, and the direction of the force is to the left; due to the difference in the asymmetric duty cycle of the voltage, the inertial force F P1 Greater than F P2 The friction between the slider and the guide rail is expressed as F f Calibration: When the voltage increases rapidly, the resultant force F on the slider is T =F m +F P1 -F f ; When the voltage decreases slowly, the resultant force on the slider is F T =F m -F P2 -F f The forward drive of the composite positioning stage can be realized by controlling the electrical signal between the electromagnetic drive unit and the piezoelectric drive unit, and two modes can be executed, namely the fast drive mode and the precise positioning mode. When the fast drive mode is executed, the electrical signal is controlled so that the resultant force on the slider is always greater than 0, and the electromagnetic drive unit applies a larger DC voltage so that the slider obtains a larger resultant force F. T When the precision positioning mode is executed, the electromagnetic drive unit electrical signal is controlled so that the resultant force on the slider is 0 when the voltage of the piezoelectric drive unit is slowly reduced, so as to suppress the displacement retreat caused by the independent displacement of the piezoelectric drive unit at this stage, and the piezoelectric drive is passed through a periodic sawtooth wave to achieve micro-feeding. In the present invention, one cycle of the sawtooth wave consists of two time periods: a voltage rising section and a voltage falling section. The duty cycle of a% means that in one cycle of the sawtooth wave, the duration of the voltage rising section accounts for a% of one 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 falling rate of the voltage falling section is also constant.

[0043] The reverse working principle is as follows Fig.11 As shown in b, reverse direct current is applied to the electromagnetic drive unit. From the force analysis, it can be seen that the magnet unit is subjected to a leftward force F at this time. m , and drives the slider to move to the left. Apply a sawtooth voltage signal of 90% to 100% to the piezoelectric drive unit. When the voltage increases slowly, the resultant force on the slider is F T =F m -F P2 -F f , when the voltage drops rapidly, the resultant force on the slider is F T =F m +F P1 -F f , where due to the application of asymmetric excitation signal, F p1 >F p2; Similar to the forward working principle, reverse driving can also achieve two working modes: rapid driving and precise positioning.

[0044] The present invention proposes a magnetic induction stacked piezoelectric inertial composite positioning platform and a driving method, in which an electromagnetic drive unit based on the voice coil motor driving principle and a piezoelectric drive unit based on the piezoelectric inertial driving principle are compositely designed. Among them, the magnet in the electromagnetic drive unit is used as a mover to avoid the influence of the lead wire of the electromagnetic drive unit on the positioning accuracy of the platform. Taking advantage of the characteristic that the piezoelectric driver is not subject to electromagnetic interference, on the one hand, the displacement and retreat movement of the piezoelectric drive unit is suppressed by electromagnetic force induction assistance, and on the other hand, the comprehensive output performance of the whole machine is improved by combining the two driving sources of electromagnetic and piezoelectric, which can effectively improve its thrust load, increase the driving speed, suppress displacement retreat, and oscillation, while ensuring that it has high-precision positioning. In addition, the present invention only has a pair of friction pairs of guide rails and sliders, and the lubrication treatment can ensure that the whole machine has good wear resistance and service life. Through the input electrical signal control of the electromagnetic drive unit and the piezoelectric drive unit, two working modes of fast drive and precise positioning can be realized. The present invention has great application prospects in the fields of active optics, super-resolution imaging sample movement, micro-nano assembly and manufacturing, integrated circuit manufacturing and detection, scanning electron microscope sample manipulation, large-scale electron beam direct writing, fiber and nano-CT, high-vacuum sample precision alignment and posture adjustment, nano-focusing and scanning, etc.

[0045] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A magnetically induced stacked piezoelectric inertial composite positioning platform, characterized in that include: A stage (1), an electromagnetic drive assembly (2), a piezoelectric drive unit (3) and a base unit (4) for carrying a driven target; The base unit is an L-shaped structure consisting of a vertical surface and a horizontal surface, the electromagnetic drive assembly comprises a coaxially arranged coil unit (2-1) and a magnet unit (2-3), the coil unit (2-1) is sleeved inside the magnet unit (2-3), a gap is provided between the two, and the two can generate relative displacement along the axis direction, wherein the magnet unit is fixedly connected to the stage (1), and the coil unit is fixedly connected to the vertical surface of the base unit; A guide rail (4-3) and a slider (4-4) cooperating with the guide rail and capable of sliding relative to the guide rail are arranged on the horizontal surface of the base unit; the piezoelectric drive unit (3) comprises an inertia block (3-1), a piezoelectric stack (3-2) and a flexible mechanism (3-3); one end of the flexible mechanism is fixedly connected to the slider (4-4) and the magnet unit (2-3), and the other end opposite thereto is provided with the inertia block (3-1); the flexible mechanism has a cavity inside and is installed with the piezoelectric stack (3-2); when the piezoelectric stack is excited, the flexible mechanism can be deformed and drive the inertia block to generate horizontal displacement.

2. The magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 1, characterized in that: The flexible mechanism is composed of a flexible mechanism connecting plate (3-3-2), a flexible mechanism oblique side beam (3-3-4), and a flexible mechanism side beam (3-3-5); Four flexible mechanism oblique side beams (3-3-4) and two flexible mechanism side beams (3-3-5) form a polygonal structure with a cavity, the piezoelectric stack (3-2) is installed in the polygonal structure, one side of the polygonal structure is connected to the flexible mechanism connecting plate (3-3-2), and the other side facing it is connected to the inertia block (3-1); The bottom surface of the flexible mechanism connecting plate (3-3-2) is connected to the slider (4-4), the top surface of the flexible mechanism connecting plate (3-3-2) is provided with a flexible mechanism arc groove (3-3-1), and the lower surface of the magnet unit (2-3) is fixedly connected to the flexible mechanism arc groove (3-3-1).

3. The magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 1, characterized in that: A lower wedge-shaped gasket (3-4) and an upper wedge-shaped gasket (3-5) are arranged between the cavity wall of the flexible mechanism and the piezoelectric stack. The lower wedge-shaped gasket and the upper wedge-shaped gasket have the same structure, and their wedge surfaces are opposite and in contact. The piezoelectric stack is wedged tightly into the hollow part of the flexible mechanism by the cooperation of the wedge surfaces of the two.

4. The magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 3, characterized in that: The included angle between the wedge surface of the lower wedge-shaped gasket and the upper wedge-shaped gasket and the vertical surface is an acute angle less than or equal to 15 degrees.

5. The magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 1, characterized in that: The movement directions of the inertia block, the slider and the magnet unit are parallel to each other; the vibration direction of the piezoelectric stack is perpendicular to the above movement directions.

6. The magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 1, characterized in that: The upper surface of the stage (1) is a plane for carrying a driven target, and the lower surface of the stage (1) is processed with a stage arc-shaped groove (1-6), the inner wall of the stage arc-shaped groove (1-6) is fitted and fixed to the upper surface of the magnet unit; one end of the stage arc-shaped groove (1-6) is closed along the groove direction, and the other end is open, and the open end faces the vertical surface of the base unit.

7. The magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 1, characterized in that: The coil unit and the magnet unit as a whole form a voice coil motor mechanism.

8. The magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 1, characterized in that: The inertia block is located between the flexible mechanism and the vertical surface of the base unit. A rectangular avoidance groove is arranged on the vertical surface of the base unit to avoid contact between the inertia block and the vertical surface of the base unit.

9. A method for driving the magnetically induced stacked piezoelectric inertial composite positioning platform according to claim 1, characterized in that The steps include: 1) The lower surface of the base unit is in contact with and fixed to the optical vibration isolation platform, and the driving target object is set on the upper surface of the stage; 2) The rightward movement is defined as the positive direction, the application of positive voltage is defined as the application of positive direct current, and the application of negative voltage is defined as the application of reverse direct current; When driving in the forward direction, a positive direct current is applied to the electromagnetic drive unit. Since the coil unit is fixed on the vertical surface of the base unit, it is subjected to a leftward force F. C The reaction force of the base unit will be offset, and the magnet unit will be subjected to a force F to the right. m , and drives the slider to move to the right; at this time, the piezoelectric drive unit is fed with a sawtooth wave with a duty cycle of 0% to 10%; when the voltage increases rapidly, the piezoelectric stack quickly extends and drives the flexible mechanism to deform, and the inertial force F of the inertial block P1 will act on the slider, and the direction of the force is to the right; when the voltage is slowly reduced, the piezoelectric stack slowly contracts, and the inertial force F of the inertial block p2 Will act on the slider, and the direction of the force is to the left; due to the difference in the asymmetric duty cycle of the voltage, the inertial force F P1 Greater than F P2 ; The friction between the slider and the guide rail is expressed as F f Calibration: When the voltage increases rapidly, the resultant force F on the slider is T =F m +F P1 -F f ; When the voltage decreases slowly, the resultant force on the slider is F T =F m -F P2 -F f ; The forward drive of the composite positioning stage can be realized by controlling the electrical signal between the electromagnetic drive unit and the piezoelectric drive unit, and two modes can be executed, namely, the fast drive mode and the precise positioning mode; when executing the fast drive mode, the electrical signal is controlled so that the resultant force on the slider is always greater than 0, and the electromagnetic drive unit applies a larger DC voltage so that the slider obtains a larger resultant force F T ; When executing the precision positioning mode, the electrical signal of the electromagnetic drive unit is controlled so that the resultant force on the slider is 0 when the voltage of the piezoelectric drive unit is slowly reduced, so as to suppress the displacement retreat caused by the independent displacement of the piezoelectric drive unit at this stage, and a periodic sawtooth wave is introduced into the piezoelectric drive to achieve micro-feeding; When working in reverse, reverse DC is applied to the electromagnetic drive unit, and the magnet unit is subjected to a leftward force F. m , and drives the slider to move to the left; apply 90% to 100% of the sawtooth wave voltage signal to the piezoelectric drive unit. When the voltage increases slowly, the resultant force on the slider is F T =F m -F P2 -F f , when the voltage drops rapidly, the resultant force on the slider is F T =F m +F P1 -F f , where due to the application of asymmetric excitation signal, F p1 >F p2 ; The working principle is the same as that of the forward direction. In reverse driving, two working modes, fast driving and precise positioning, can also be achieved.

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