A high-precision, long-stroke dual-object linear actuator

Abstract

The present invention belongs to a high-precision long-stroke dual-object linear driver, including a slide rail, a first bearing platform, a second bearing platform, a permanent magnet and a retractable piezoelectric element. The slide rail is slidably connected to the first bearing platform and the second bearing platform, one end of the retractable piezoelectric element is fixedly connected to the first bearing platform, and the other end of the retractable piezoelectric element is fixedly connected to the permanent magnet. The material of the second bearing platform is ferromagnetic material. The second bearing platform is slidably connected to the slide rail, and the permanent magnet is adsorbed on the second bearing platform. The retractable piezoelectric element is extended or contracted after applying a driving voltage, so that the first bearing platform and the second bearing platform slide in the slide rail. The high-precision long-stroke dual-object linear driver system provided by the present invention is driven by a single retractable piezoelectric element, has low complexity, can greatly reduce the size of the device, and can realize the independent driving of two objects at the same time, and both objects can be positioned with high precision (several nanometers) and long stroke (several millimeters or centimeters).

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical manufacturing, and in particular relates to a high-precision and long-stroke dual-object linear driver. Background Art

[0002] Precision linear actuators are one of the important components of modern manufacturing and automation equipment. They are widely used in various precision positioning, processing and control fields, such as optical component positioning, semiconductor processing, aerospace, and missile equipment. In many precision systems, it is often necessary to position two or more objects. In addition, it is also required to be able to position objects with high precision and long strokes. For example, in a zoom system with autofocus and zoom functions, a focus lens group and a zoom lens group are required to change the focal length of the entire system. Therefore, the two lens groups need to be positioned independently, and each can achieve high-precision and long-stroke positioning.

[0003] Piezoelectric elements have the characteristics of high precision (several nanometers), fast response (tens of thousands of hertz), and small size (several millimeters). Therefore, they are widely used in precision actuators for nano-level positioning. Since the stroke of the piezoelectric element itself is limited (several microns), long-distance motion positioning cannot be achieved. Therefore, in order to expand the stroke of the piezoelectric element, impact drive mechanism (IDM) and smooth impact drive mechanism (SIDM) are two effective driving methods. Not only can high-precision (several nanometers) positioning be achieved, but also long-stroke (several millimeters or centimeters) movement can be performed. However, a linear actuator can often only position one object or device, and cannot achieve independent positioning of two objects. Independent positioning of two objects often requires two independent actuators, which results in a complex structure, space occupation, and large size. Summary of the invention

[0004] The present invention aims to overcome the deficiencies in the prior art and to provide a high-precision, long-stroke dual-object linear actuator, which can achieve independent positioning of two objects using a single linear actuator.

[0005] The objective of the present invention is achieved as follows: a high-precision, long-stroke dual-object linear actuator comprises a slide rail, a first bearing platform, a second bearing platform, a permanent magnet and a retractable piezoelectric element, the slide rail is slidably connected to the first bearing platform and the second bearing platform, one end of the retractable piezoelectric element is fixedly connected to the first bearing platform, the other end of the retractable piezoelectric element is fixedly connected to the permanent magnet, the material of the second bearing platform is ferromagnetic material, the second bearing platform is slidably connected to the slide rail, the permanent magnet is adsorbed on the second bearing platform, and the retractable piezoelectric element is extended or contracted after a driving voltage is applied, so that the first bearing platform and the second bearing platform slide in the slide rail.

[0006] Preferably, the high-precision, long-stroke dual-object linear actuator also includes an electrode for realizing independent driving of the first carrier platform and the second carrier platform. The electrode is arranged on the inclined surface of the slide rail for locking or unlocking the first carrier platform. When the electrode is energized, the electrode generates static electricity for adsorbing and locking the first carrier platform, so that the first carrier platform and the slide rail remain relatively stationary, and after applying a driving voltage to the retractable piezoelectric element, the second carrier platform is driven to slide on the slide rail. When the electrode is de-energized and unlocked, the electrode releases the first carrier platform, and after applying a driving voltage to the retractable piezoelectric element, the first carrier platform is driven to slide in the slide rail.

[0007] Preferably, the slide rail includes a slide groove, which includes a central groove for isolating electrodes, inclined surfaces symmetrically arranged on both sides of the central groove from bottom to top, a first sliding surface, a second sliding surface and a limiting surface, the first sliding surface is vertically arranged to cooperate with the side clearance of the first bearing platform, the first bearing platform slides between the two symmetrical first sliding surfaces, the second sliding surface is perpendicular to the first sliding surface, the second sliding surface contacts the lower surface of the second bearing platform, the second bearing platform slides on the second sliding surface, and the limiting surface cooperates with the side clearance of the second bearing platform to limit the lateral movement of the second bearing platform.

[0008] Preferably, there is a rising edge and a falling edge in one voltage cycle of the driving voltage, and the stretchable piezoelectric element stretches when the driving voltage is in the voltage interval of the rising edge, and the stretchable piezoelectric element contracts when the driving voltage is in the voltage interval of the falling edge.

[0009] Preferably, one driving stroke includes one or more voltage cycles, and one or more voltage cycles constitute the entire voltage cycle of one driving stroke.

[0010] Preferably, when driven by the rising edge of the voltage, the direction of extension of the stretchable piezoelectric element is the positive direction, and when driven by the falling edge of the voltage, the direction of contraction of the stretchable piezoelectric element is the negative direction. Within a voltage cycle, when the proportion of the rising edge is greater than the proportion of the falling edge, the speed of extension of the stretchable piezoelectric element is less than the speed of contraction of the stretchable piezoelectric element; when the proportion of the rising edge is less than the proportion of the falling edge, the speed of extension of the stretchable piezoelectric element is greater than the speed of contraction of the stretchable piezoelectric element.

[0011] Preferably, two electrodes are provided, namely a first electrode and a second electrode, which are respectively fixed on the inclined surfaces on both sides of the central groove.

[0012] Preferably, the first electrode is connected to a forward voltage, and the second electrode is connected to a reverse voltage to adsorb the first supporting platform.

[0013] Preferably, the first supporting platform is grounded, and the first electrode and the second electrode are both connected to a forward voltage or a reverse voltage at the same time to adsorb the first supporting platform.

[0014] Preferably, an insulating layer is provided on the surface of the electrode to prevent the first supporting platform from directly contacting the electrode.

[0015] The high-precision and long-stroke dual-object linear actuator system provided by the present invention is driven by a single retractable piezoelectric element, has low complexity, can greatly reduce the size of the equipment, and can simultaneously realize independent driving of the two objects, and both objects can be positioned with high precision (several nanometers) and long stroke (several millimeters or centimeters). BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of a high-precision long-stroke dual-object linear actuator in one embodiment of the present invention;

[0017] Figure 2 A front view of a high-precision, long-stroke dual-object linear actuator according to an embodiment of the present invention;

[0018] Figure 3 It is a schematic structural diagram of a slide rail in one embodiment of a high-precision, long-stroke dual-object linear actuator of the present invention;

[0019] Figure 4 is a voltage cycle of a driving voltage of a high-precision long-stroke dual-object linear actuator in one embodiment of the present invention;

[0020] Figure 5 It is a schematic diagram of an IDM driving mode of a high-precision long-stroke dual-object linear actuator in one embodiment of the present invention;

[0021] Figure 6 A schematic diagram of the driving performance of the first carrier platform under different voltage amplitudes in one embodiment of the high-precision long-stroke dual-object linear actuator of the present invention;

[0022] Figure 7 Schematic diagram of the driving performance of the first carrier at different voltage frequencies of the high-precision long-stroke dual-object linear actuator in one embodiment of the present invention

[0023] Figure 8A schematic diagram of an electrostatic adsorption method of a high-precision long-stroke dual-object linear actuator in one embodiment of the present invention;

[0024] Fig. 9 A schematic diagram of an electrostatic adsorption method of a high-precision long-stroke dual-object linear actuator in one embodiment of the present invention;

[0025] Fig.10 For the present invention Figure 8 and Fig. 9 Performance comparison chart of two different electrostatic adsorption methods;

[0026] Fig.11 A schematic diagram of a SIDM driving mode of a high-precision long-stroke dual-object linear actuator in one embodiment of the present invention;

[0027] Fig.12 A schematic diagram of the driving performance of the second carrier platform under different voltage amplitudes in one embodiment of the high-precision long-stroke dual-object linear actuator of the present invention;

[0028] Fig.13 A schematic diagram of the driving performance of the second carrier platform under different voltage frequencies in one embodiment of the high-precision long-stroke dual-object linear actuator of the present invention;

[0029] Fig.14 Schematic diagram of the high-precision driving performance of the second carrier platform in one embodiment of the high-precision long-stroke dual-object linear actuator of the present invention. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. Preferred embodiments of the present invention are provided in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0031] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0032] Figure 1 and Figure 2The schematic diagram of the structure of the high-precision long-stroke dual-object linear actuator of the present invention is shown, which includes a high-precision long-stroke dual-object linear actuator, including a slide rail 10, a first bearing platform 20, a second bearing platform 30, a permanent magnet 40 and a retractable piezoelectric element 50, the slide rail 10 is slidably connected to the first bearing platform 20 and the second bearing platform 30, one end of the retractable piezoelectric element 50 is fixedly connected to the first bearing platform 20, and the other end of the retractable piezoelectric element 50 is fixedly connected to the permanent magnet 40, the material of the slide rail 10 is insulating material, the material of the second bearing platform 30 is ferromagnetic material, the second bearing platform 30 is slidably connected to the slide rail 10, the permanent magnet 40 is adsorbed on the second bearing platform 30, and the retractable piezoelectric element 50 is extended or contracted after a driving voltage is applied, so that the first bearing platform 20 and the second bearing platform 30 slide in the slide rail 10.

[0033] One end of the retractable piezoelectric element 50 is fixedly connected to the first carrier 20 by epoxy resin industrial glue, and the other end of the retractable piezoelectric element 50 is fixedly connected to the permanent magnet 40 by epoxy resin industrial glue. The upper surface of the permanent magnet 40 is in contact with the lower surface of the second carrier 30 by magnetic force. The material of the second carrier 30 is steel, and it can be replaced with other ferromagnetic materials if the application environment requires it.

[0034] Further, such as Figure 1 and Figure 2 As shown, the high-precision long-stroke dual-object linear actuator also includes an electrode 60 for realizing independent driving of the first carrier 20 and the second carrier 30. The electrode 60 is arranged on the inclined surface of the slide rail 10 for locking or unlocking the first carrier 20. When the electrode 60 is powered on, the electrode 60 generates static electricity for adsorbing and locking the first carrier 20, so that the first carrier 20 and the slide rail 10 remain relatively still, and after applying a driving voltage to the retractable piezoelectric element, the second carrier is driven to slide on the slide rail, and the second carrier can be positioned for a long stroke and high precision. When the electrode 60 is powered off and unlocked, the electrode 60 releases the first carrier 20, and after applying a driving voltage to the retractable piezoelectric element, the first carrier 20 is driven to slide in the slide rail 10, and the first carrier can be positioned for a long stroke and high precision.

[0035] Furthermore, an insulating layer is provided on the surface of the electrode 60, and the insulating layer is made of a plastic film or other insulating films. The insulating layer can prevent the first carrier 20 from directly contacting the electrode 60, thereby preventing the loss of electrostatic charge and the influence of the external environment.

[0036] Further, such as Figure 3As shown, the slide rail 10 includes a slide groove, which includes a central groove 101 for isolating electrodes, inclined surfaces 102 symmetrically arranged on both sides of the central groove 101 from bottom to top, a first sliding surface 103, a second sliding surface 104 and a limiting surface 105. The first sliding surface 103 is vertically arranged to cooperate with the side clearance of the first bearing platform 20. The first bearing platform 20 slides between the two symmetrical first sliding surfaces 103. The second sliding surface 104 is perpendicular to the first sliding surface 103. The second sliding surface 104 contacts the lower surface of the second bearing platform 30. The second bearing platform 30 slides on the second sliding surface 104. The limiting surface 105 cooperates with the side clearance of the second bearing platform 30 to limit the lateral movement of the second bearing platform 30.

[0037] The cross-section of the upper part of the first supporting platform 20 is square, and the cross-section of the lower part of the first supporting platform 20 is triangular. The two side surfaces of the upper part of the first supporting platform 20 are gap-matched with the first sliding surface 103 of the slide groove, and the lower part of the first supporting platform 20 is in contact with the insulating layer on the surface of the electrode 60 arranged in the slide groove.

[0038] The second carrying platform 30 is made of a plate-shaped ferromagnetic material and can slide on the second sliding surface 104. The limiting surface 105 limits the lateral movement of the second carrying platform 30.

[0039] The first carrying platform 20 slides between the first sliding surfaces 103 , and the second carrying platform 30 slides on the second sliding surfaces 104 .

[0040] Further, such as Figure 1 and Figure 2 As shown, the upper surface of the first carrier 20 and the upper surface of the retractable piezoelectric element 50 are arranged on the lower side of the lower surface of the second carrier 30 to avoid collision between the first carrier 20 and the second carrier 30 and the retractable piezoelectric element 50.

[0041] Furthermore, the angle between the inclined surfaces 102 is greater than 0° and less than 180°, preferably 90°.

[0042] Further, such as Figure 4 As shown, there is a rising edge 7 and a falling edge 8 in one voltage cycle of the driving voltage. When the driving voltage is in the voltage interval of the rising edge 7, the stretchable piezoelectric element 50 is extended, and when the driving voltage is in the voltage interval of the falling edge 8, the stretchable piezoelectric element 50 is contracted. By applying a driving voltage having a rising edge 7 and a falling edge 8, the stretchable piezoelectric element 50 is extended or contracted.

[0043] Furthermore, when driven by the rising edge 7 of the voltage, the direction in which the stretchable piezoelectric element 50 extends is the positive direction, and when driven by the falling edge 8 of the voltage, the direction in which the stretchable piezoelectric element 50 contracts is the negative direction. In the entire voltage cycle, when the proportion of the rising edge 7 is greater than the proportion of the falling edge 8, the stretchable piezoelectric element 50 extends at a speed lower than the stretchable piezoelectric element 50 contracts; when the proportion of the rising edge 7 is less than the proportion of the falling edge 8, the stretchable piezoelectric element 50 extends at a speed higher than the stretchable piezoelectric element 50 contracts.

[0044] The proportion of rising edge 7 is expressed as the proportion of the time of rising edge 7 to the entire voltage cycle time:

[0045] The proportion of rising edge 7 = rising edge time ÷ the entire voltage cycle time × 100%

[0046] The proportion of falling edge 8 is expressed as the proportion of the time of falling edge 8 to the entire voltage cycle time:

[0047] The proportion of falling edge 8 = falling edge time ÷ the entire voltage cycle time × 100%

[0048] When the proportion of the rising edge 7 of the driving voltage is greater than 50% (the proportion of the rising edge 7 in the entire voltage cycle is greater than the proportion of the falling edge 8 in the entire voltage cycle), the driving voltage first rises slowly and then drops quickly. Correspondingly, the retractable piezoelectric element 50 first stretches slowly and then contracts quickly. When the proportion of the rising edge 7 is less than 50% (the proportion of the rising edge 7 in the entire voltage cycle is less than the proportion of the falling edge 8 in the entire voltage cycle), the driving voltage first rises quickly and then drops slowly. Correspondingly, the retractable piezoelectric element 50 first stretches quickly and then contracts slowly.

[0049] like Figure 5 As shown, the movement of the first carrier 20 is realized by the IDM driving mode. Figure 5 As shown in (a), the entire linear drive is in the initial state. Next, a driving voltage with a rising edge 7 accounting for more than 50% is applied to the stretchable piezoelectric element 50. Figure 5 As shown in (b), at the rising edge 7 of the driving voltage, the retractable piezoelectric element 50 slowly extends, pushing the permanent magnet 40 to move in the positive direction to the right. The first carrier 20 remains stationary due to the static friction between the insulating layer on the surface of the two electrodes 60. Again, at the falling edge 8 of the driving voltage, the retractable piezoelectric element 50 contracts rapidly. Figure 5As shown in (c), the rapid contraction of the retractable piezoelectric element 50 generates an impact force on the first carrier platform 20. The impact force is greater than the maximum static friction between the first carrier platform 20 and the insulating layer on the surface of the two electrodes 60 and can pull the first carrier platform 20 to move in the direction of the permanent magnet 40. Due to the conservation of momentum, the first carrier platform 20 can be driven to the right in the positive direction. By repeating the above driving voltage continuously, the first carrier platform 20 can achieve long-stroke positioning in the positive direction, which can theoretically reach infinity. In practice, it can be reasonably selected according to the size of the slide rail 10. If the first carrier platform 20 needs to move in a long stroke in the negative direction, the proportion of the above driving voltage rising edge 7 can be adjusted to less than 50%.

[0050] The highest positioning accuracy of the first carrier 20 is the moving distance within a single driving voltage cycle when the first carrier 20 just overcomes the maximum static friction between the insulating layer on the surface of the first carrier 20 and the two electrodes 60. For example, when the amplitude of the driving voltage is 10V, the frequency is 20kH, and the proportion of the rising edge 7 is 80%, the first carrier 20 can just overcome the maximum static friction between the insulating layer on the surface of the first carrier 20 and the two electrodes 60, and produce movement relative to the slide rail 10, and the moving distance relative to the slide rail 10 within one voltage cycle is 50 nanometers, then the highest positioning accuracy of the first carrier 20 is 50 nanometers. The moving distance of the first carrier 20 can be adjusted as needed, such as increasing the amplitude of the voltage, selecting a more suitable voltage frequency or voltage proportion, etc., which can increase the moving distance of the first carrier 20 within a single voltage cycle. If it is necessary to drive the first carrier 20 to move a longer distance than a single voltage cycle, multiple voltage cycles can be applied to make the first carrier 20 move continuously for long-stroke positioning.

[0051] like Figure 6 As shown, taking a voltage frequency of 35kHz and a rising edge 7 ratio of 80% as an example, the applied voltage amplitude is increased from 15V to 60V. Due to insufficient impact force at a smaller voltage, the speed of the first carrier 20 below 15V is 0mm / s, and no relative motion occurs. When the applied voltage reaches 22.5V, the first carrier 20 begins to move. The moving speed of the first carrier 20 increases with the increase of the applied voltage, and reaches its maximum speed of 31.7mm / s at 60V. In addition, under the minimum movement condition of 22.5V, it can be determined that the moving distance of the first carrier 20 in each voltage cycle is 60nm, that is, the highest positioning accuracy of the first carrier 20.

[0052] Then, the performance of the first carrier 20 at different voltage frequencies is analyzed with a voltage of 60V and a rising edge 7 ratio of 80%. Figure 7As shown in the figure, when the voltage frequency is less than 35kHz, the moving speed of the first carrier 20 increases with the increase of the voltage frequency, and reaches a maximum speed of 31.7mm / s when the voltage frequency is 35kHz. When the voltage frequency exceeds 35kHz, the system resonance begins to affect the movement of the first carrier 20, causing its speed to begin to decrease. Therefore, it is preferred to perform the IDM driving mode with a 60V voltage at a frequency of 35kHz and a driving voltage with a rising edge 7 accounting for 80%.

[0053] Further, such as Figure 1 and Figure 2 As shown, two electrodes 60 are provided, namely a first electrode 601 and a second electrode 602, which are respectively fixed on the inclined surfaces 102 on both sides of the central groove.

[0054] After taking into account the influence of the air gap between the electrode 60 and the insulating layer on the surface of the electrode 60, the electrostatic adsorption force of the electrode 60 can be calculated by the following formula.

[0055]

[0056] Among them, F ad e is the theoretical electrostatic adsorption force of the electrode 60, S is the area of ​​the electrode 60, ε0 is the vacuum dielectric constant, d0 is the air gap between the electrode 60 and the insulating layer on the surface of the electrode 60, d1 is the thickness of the insulating layer, ε r is the relative dielectric constant of the insulating layer, and V is the voltage.

[0057] Different electrode 60 areas, air gap sizes, insulation layer thicknesses, insulation layer relative dielectric constants, and voltages may be set to reasonably obtain electrostatic adsorption forces of different magnitudes.

[0058] Further, such as Figure 8 As shown, the first electrode 601 is connected to a forward voltage, and the second electrode 602 is connected to a reverse voltage to adsorb the first carrier 20 .

[0059] Further, such as Fig. 9 As shown, the first carrier platform 20 is grounded, and the first electrode 601 and the second electrode 602 are both connected to a forward voltage or a reverse voltage at the same time to adsorb the first carrier platform 20 .

[0060] like Fig.10 As shown in the figure, scheme 1 is Figure 8 The connection method shown, scheme 2 is Fig. 9 The connection method shown. Fig.10 It can be seen that the electrostatic adsorption force generated by scheme 2 is significantly greater than the electrostatic adsorption force generated by scheme 1. Therefore, in the preferred scheme 2, both the first electrode 601 and the second electrode 602 are connected to a forward voltage or a reverse voltage at the same time, and the first carrier 20 is grounded.

[0061] After a certain voltage is applied to the two electrodes 60, the first carrier 20 and the two electrodes 60 are adsorbed together and remain stationary at the original position. At this time, the linear drive is converted from the previous IDM drive mode to the SIDM drive mode, and the second carrier 30 can be driven. First, as Fig.11 As shown in (a), the entire linear drive is in the initial state. Next, a driving voltage with a rising edge 7 accounting for more than 50% is applied to the stretchable piezoelectric element 50. Fig.11 As shown in (b), at the rising edge 7 of the driving voltage, the retractable piezoelectric element 50 slowly extends, pushing the permanent magnet 40 to move in the positive direction to the right. Due to the static friction between the permanent magnet 40 and the second carrier 30, the second carrier 30 can move with the permanent magnet 40. Again, at the falling edge 8 of the driving voltage, the retractable piezoelectric element 50 shrinks rapidly. Fig.11 As shown in (c), due to inertia, the second carrier 30 cannot move following the rapid movement of the permanent magnet 40, so that the second carrier 30 stays in the original position. By continuously repeating the above driving voltage, the second carrier 30 can achieve long-stroke positioning in the positive direction. To achieve long-stroke movement in the negative direction of the second carrier 30, the proportion of the rising edge 7 of the above driving voltage can be adjusted to less than 50%. To achieve high-precision positioning of the second carrier 30, a slowly changing DC voltage can be applied to the retractable piezoelectric element 50, so that the permanent magnet 40 can drive the second carrier 30 to move slowly, and the positioning accuracy of the second carrier 30 can reach the positioning accuracy of the retractable piezoelectric element 50 itself, which can reach several nanometers.

[0062] like Fig.12 As shown, when the voltage frequency is 9kHz and the proportion of rising edges 7 is 80%, the second carrier 30 does not move until the voltage amplitude is higher than 15V. When the voltage amplitude is between 15V and 60V, the movement speed of the second carrier 30 increases with the increase of the voltage amplitude.

[0063] like Fig.13 As shown, taking 60V voltage and 80% rising edge ratio as an example, different voltage frequencies from 2kHz to 18kHz are applied. The second carrier 30 does not start to move until the voltage frequency exceeds 2kHz, and the speed increases with the increase of frequency, and reaches a maximum speed of 16mm / s at 9kHz, and then the speed begins to decrease after it is greater than 9kHz. Since the second carrier 30 is driven by the friction between the second carrier 30 and the permanent magnet 40, the stick-slip performance during friction may be affected at high frequencies, and the moving speed of the second carrier 30 may be reduced. When the frequency reaches 18kHz, the speed of the second carrier 30 drops to zero.

[0064] like Fig.14As shown, in order to study the high-precision positioning performance of the second supporting platform 30, a voltage of 0.6V is applied to the stretchable piezoelectric element 50 each time. It can be seen that each time a voltage of 0.6V is applied to the stretchable piezoelectric element 50, the corresponding displacement of the second supporting platform 30 can reach 13nm.

[0065] The present invention is aimed at linear drive in miniaturized equipment and proposes a high-precision long-stroke dual-object linear drive. Long-stroke positioning and high-precision positioning of the first carrier 20 are achieved through the IDM drive mode, and long-stroke positioning and high-precision positioning of the second carrier 30 are achieved through the SIDM drive mode. Since the second carrier 30 may produce partial interference in the IDM drive mode, the first carrier 20 should generally be positioned by the IDM drive mode first, and then the second carrier 30 should be positioned by the SIDM drive mode.

[0066] The present invention realizes the conversion between the IDM driving mode and the SIDM driving mode by electrostatically adsorbing / releasing the first carrier 20. The IDM driving mode is used to drive the first carrier 20, and the SIDM driving mode is used to drive the second carrier 30, thereby realizing the independent driving of the first carrier 20 and the second carrier 30, and achieving the purpose of high-precision and long-stroke driving of the two carriers. The development of this driver has important application significance in the fields of biomedicine, optical positioning, precision machining, etc.

[0067] The above examples are only preferred examples of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision, long-stroke dual-object linear actuator, characterized in that: The invention comprises a slide rail, a first bearing platform, a second bearing platform, a permanent magnet and a retractable piezoelectric element, wherein the slide rail is slidably connected to the first bearing platform and the second bearing platform, one end of the retractable piezoelectric element is fixedly connected to the first bearing platform, and the other end of the retractable piezoelectric element is fixedly connected to the permanent magnet, the material of the second bearing platform is ferromagnetic material, the second bearing platform is slidably connected to the slide rail, the permanent magnet is adsorbed on the second bearing platform, and the retractable piezoelectric element is extended or contracted after a driving voltage is applied, so that the first bearing platform and the second bearing platform slide in the slide rail; the upper surface of the first bearing platform and the upper surface of the retractable piezoelectric element are arranged on the lower side of the lower surface of the second bearing platform; The high-precision long-stroke dual-object linear actuator also includes an electrode for realizing independent driving of the first carrier platform and the second carrier platform, the electrode is arranged on the inclined surface of the slide rail for locking or unlocking the first carrier platform, when the electrode is powered on, the electrode generates static electricity for adsorbing and locking the first carrier platform, so that the first carrier platform and the slide rail remain relatively still, and after applying a driving voltage to the retractable piezoelectric element, the second carrier platform is driven to slide on the slide rail, and when the electrode is powered off and unlocked, the electrode releases the first carrier platform, and after applying the driving voltage to the retractable piezoelectric element, the first carrier platform is driven to slide in the slide rail; The slide rail includes a slide groove, and the slide groove includes a central groove for isolating electrodes, inclined surfaces symmetrically arranged on both sides of the central groove from bottom to top, a first sliding surface, a second sliding surface and a limiting surface, the first sliding surface is vertically arranged to cooperate with the side clearance of the first bearing platform, the first bearing platform slides between the two symmetrical first sliding surfaces, the second sliding surface is perpendicular to the first sliding surface, the second sliding surface contacts the lower surface of the second bearing platform, the second bearing platform slides on the second sliding surface, and the limiting surface cooperates with the side clearance of the second bearing platform to limit the lateral movement of the second bearing platform.

2. The high-precision long-stroke dual-object linear actuator according to claim 1, characterized in that: The driving voltage has a rising edge and a falling edge in one voltage cycle. The stretchable piezoelectric element is extended in the voltage interval of the rising edge, and the stretchable piezoelectric element is contracted in the voltage interval of the falling edge.

3. The high-precision long-stroke dual-object linear actuator according to claim 2, characterized in that: One driving stroke includes one or more of the voltage cycles, and one or more of the voltage cycles constitute the entire voltage cycle of one driving stroke.

4. The high-precision long-stroke dual-object linear actuator according to claim 3, characterized in that: When the rising edge is driven, the direction in which the stretchable piezoelectric element extends is the positive direction, and when the falling edge is driven, the direction in which the stretchable piezoelectric element contracts is the negative direction. In the entire voltage cycle, when the proportion of the rising edge is greater than the proportion of the falling edge, the stretchable piezoelectric element extends at a speed less than the contraction speed of the stretchable piezoelectric element; when the proportion of the rising edge is less than the proportion of the falling edge, the stretchable piezoelectric element extends at a speed greater than the contraction speed of the stretchable piezoelectric element.

5. The high-precision long-stroke dual-object linear actuator according to claim 1, characterized in that: The electrodes are provided with two first electrodes and second electrodes, which are respectively fixed on the inclined surfaces at both sides of the central groove.

6. The high-precision long-stroke dual-object linear actuator according to claim 5, characterized in that: The first electrode is connected to a forward voltage, and the second electrode is connected to a reverse voltage to adsorb the first supporting platform.

7. The high-precision long-stroke dual-object linear actuator according to claim 6, characterized in that: The first supporting platform is grounded, and the first electrode and the second electrode are both connected to a forward voltage or a reverse voltage at the same time to adsorb the first supporting platform.

8. The high-precision long-stroke dual-object linear actuator according to claim 6, characterized in that: An insulating layer is provided on the surface of the electrode to prevent the first supporting platform from directly contacting the electrode.

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