Nanometer holder with high static and low dynamic stiffness characteristics

Abstract

The invention discloses a nano holder with high static and low dynamic stiffness characteristics. The nano holder comprises a base frame, an output platform, an atomic force microscope probe and a quasi-zero stiffness mechanism, the output platform is movably installed on the base frame in the vertical direction. The atomic force microscope probe is mounted on the output platform; the quasi-zero stiffness mechanism comprises a first mounting block, a second mounting block and a quasi-zero stiffness unit, the quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block, the first mounting block is used for being connected with the base frame, and the second mounting block is used for being connected with the output platform; the quasi-zero stiffness unit comprises a positive stiffness mechanism and a negative stiffness mechanism, the positive stiffness mechanism is used for applying supporting force to the output platform, and the negative stiffness mechanism is arranged in the horizontal direction and is configured to counteract the stiffness of the positive stiffness mechanism in the vertical direction when the positive stiffness mechanism applies the supporting force to the output platform. A quasi-zero stiffness structure is introduced into the nano holder, so that the nano holder obtains a lower system inherent frequency.

Description

Technical Field

[0001] The invention relates to the technical field of vibration reduction of precision instruments, and in particular to a nanometer pan / tilt platform with high static and low dynamic stiffness characteristics. Background Art

[0002] The nano-PTZ with active / passive vibration suppression is a comprehensive vibration isolation platform that combines active and passive vibration isolation technologies. It is designed to provide more efficient and comprehensive vibration control to meet the stringent requirements of vibration-sensitive equipment or systems.

[0003] In order to improve the vibration reduction capability of the resonance region of the traditional active / passive suppression fusion nano-PTZ, the method of increasing damping in the passive vibration isolation system is usually adopted to suppress the resonance frequency and increase the bandwidth.

[0004] However, the vibration reduction method of increasing damping weakens the characteristic of the passive vibration isolation device in suppressing vibration in the high frequency band. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to propose a nano pan-tilt platform with high static and low dynamic stiffness characteristics, which can achieve the characteristics of high static stiffness and low dynamic stiffness by introducing a quasi-zero stiffness structure, and achieve a lower system natural frequency without losing the load-bearing capacity and stability, thereby achieving the vibration suppression effect in the resonance area and high-frequency area.

[0006] The present invention proposes a nanometer pan-tilt with high static and low dynamic stiffness characteristics, the nanometer pan-tilt comprises a base frame, an output platform, an atomic force microscope probe and a quasi-zero stiffness mechanism; the output platform is movably mounted on the base frame along the vertical direction; the atomic force microscope probe is mounted on the output platform; the quasi-zero stiffness mechanism comprises a first mounting block, a second mounting block and a quasi-zero stiffness unit, the quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block, the first mounting block is used to connect the base frame, and the second mounting block is used to connect the output platform; the quasi-zero stiffness unit comprises a positive stiffness mechanism and a negative stiffness mechanism, the positive stiffness mechanism is used to apply a supporting force to the output platform, the negative stiffness mechanism is arranged along the horizontal direction and is configured to offset the stiffness of the positive stiffness mechanism in the vertical direction when the positive stiffness mechanism applies a supporting force to the output platform.

[0007] In some embodiments, the first mounting block and the second mounting block are arranged along the vertical direction; the positive stiffness mechanism includes four positive stiffness elastic members connected end to end, the positive stiffness elastic members are connected and sequentially form a first intersection, a second intersection, a third intersection and a fourth intersection, and each of the positive stiffness elastic members is configured to rotate relative to an intersection; the negative stiffness mechanism includes a negative stiffness elastic member, one end of the negative stiffness elastic member is connected to the first intersection, the other end of the negative stiffness elastic member is connected to the third intersection, and a line between the first intersection and the third intersection is parallel to the horizontal direction; the second intersection is fixed to the first mounting block, and the fourth intersection is fixed to the second mounting block.

[0008] In some embodiments, a line between the second intersection point and the fourth intersection point is parallel to the vertical direction.

[0009] In some embodiments, the quasi-zero stiffness unit is a one-piece piece.

[0010] In some embodiments, the first mounting block and the second mounting block are arranged along the vertical direction; the quasi-zero stiffness unit includes a frame, the frame includes four trusses connected end to end, and two adjacent trusses are rotatably arranged; the positive stiffness mechanism includes a positive stiffness elastic member, the positive stiffness elastic member is arranged at a diagonal of the frame, one end of the positive stiffness elastic member is hinged to a first frame intersection of the frame, and the other end of the positive stiffness elastic member is hinged to a third frame intersection of the frame, the first frame intersection is connected to the first mounting block, and the third frame intersection is connected to the second mounting block; the negative stiffness mechanism includes a negative stiffness elastic member, the negative stiffness elastic member is arranged at another diagonal of the frame, one end of the negative stiffness elastic member is hinged to the second frame intersection of the frame, and the other end of the negative stiffness elastic member is hinged to the fourth frame intersection of the frame; the positive stiffness elastic member is arranged parallel to the vertical direction, and the negative stiffness elastic member is arranged parallel to the horizontal direction.

[0011] In some embodiments, different diagonals of the frame intersect to form a fifth frame intersection; there are two positive stiffness elastic members, one is disposed between the first frame intersection and the fifth frame intersection, and the other is disposed between the third frame intersection and the fifth frame intersection; there are two negative stiffness elastic members, one is disposed between the second frame intersection and the fifth frame intersection, and the other is disposed between the fourth frame intersection and the fifth frame intersection.

[0012] In some embodiments, the nano-pan head further comprises a flexible leaf spring, one end of which is connected to the base frame, and the other end of which is connected to the output platform, and the flexible leaf spring is used to apply elastic force in the vertical direction to the output platform.

[0013] In some embodiments, the first mounting block and the second mounting block are arranged along the horizontal direction; the positive stiffness mechanism includes a flexible leaf spring member, one end of which is connected to the first mounting block, and the other end of which is connected to the second mounting block, and the flexible leaf spring member deflects and deforms to apply an elastic force in the vertical direction; the negative stiffness mechanism includes a negative stiffness elastic member, one end of which is connected to the first mounting block, and the other end of which is connected to the second mounting block.

[0014] In some embodiments, the first mounting block and the second mounting block are arranged along the vertical direction; the first mounting block has a mounting groove, and the second mounting block is movably arranged in the mounting groove along the vertical direction; the positive stiffness mechanism includes a positive stiffness elastic member, one end of the positive stiffness elastic member is connected to the bottom wall of the mounting groove, and the other end of the positive stiffness elastic member is connected to the top wall of the second mounting block; the negative stiffness mechanism includes a negative stiffness elastic member, and the negative stiffness elastic member is a plurality of negative stiffness elastic members arranged at intervals around the first mounting block, one end of each of the negative stiffness elastic members is connected to the groove peripheral wall of the mounting groove, and the other end of each of the negative stiffness elastic members is on the side peripheral wall of the second mounting block; the extension lines of the negative stiffness elastic members intersect on the straight line where the positive stiffness elastic member is located.

[0015] In some embodiments, the nano-pan-tilt platform further includes a hard spring component, one end of which is connected to the base frame, and the other end of which is connected to the output platform, and the hard spring component is used to apply elastic force in the vertical direction to the output platform.

[0016] It can be seen from the technical solution that the embodiment provided by the present invention has the following advantages: the first mounting block is fixedly connected to the base frame, the second mounting block is fixedly connected to the output platform, the quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism, the positive stiffness mechanism can apply a supporting force to the output platform, that is, the direction of the supporting force generated by the positive stiffness mechanism is parallel to the vertical direction and opposite to the direction of the gravity on the output platform, so the positive stiffness mechanism increases the bearing capacity, and the static stiffness is maintained at a high level; the negative stiffness mechanism is arranged in the horizontal direction, and when the positive stiffness mechanism applies a supporting force to the output platform, the negative stiffness mechanism offsets the stiffness of the positive stiffness mechanism in the vertical direction, that is, the positive stiffness mechanism and the negative stiffness mechanism are connected in parallel, and its dynamic stiffness is close to zero. This means that the quasi-zero stiffness unit exhibits a strong bearing capacity when subjected to static loads, and exhibits a lower stiffness when facing dynamic loads, which is conducive to achieving vibration isolation and vibration reduction effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 is a schematic diagram of the overall structure of the nano pan-tilt head according to the first embodiment;

[0019] Figure 2 This is a comparison chart of the vibration suppression effect of the nano gimbal. The three different types of lines in the figure respectively represent the vibration suppression effect of the traditional active / passive vibration suppression fusion nano gimbal, the vibration suppression effect after adding damping to the traditional active / passive vibration suppression fusion nano gimbal, and the vibration suppression effect after adding a quasi-zero stiffness mechanism to the traditional active / passive vibration suppression fusion nano gimbal;

[0020] Figure 3 is a schematic diagram of the overall structure of the nano pan-tilt platform of the second embodiment;

[0021] Figure 4 is a schematic diagram of a quasi-zero stiffness mechanism of a second embodiment;

[0022] Figure 5 is a schematic diagram of the overall structure of the nano pan-tilt platform of the third embodiment;

[0023] Figure 6 is a schematic diagram of a quasi-zero stiffness mechanism of a third embodiment;

[0024] Figure 7 is a schematic diagram of the overall structure of the nano pan-tilt head according to the fourth embodiment;

[0025] Figure 8 is a schematic diagram of a quasi-zero stiffness mechanism of a fourth embodiment;

[0026] Fig. 9 is a schematic diagram of the overall structure of the nano pan-tilt platform according to the fifth embodiment;

[0027] Fig.10 It is a schematic diagram of the quasi-zero stiffness mechanism of the fifth embodiment.

[0028] Reference numerals:

[0029] First embodiment:

[0030] A nano-pan-tilt platform 101 with high static and low dynamic stiffness characteristics, a base frame 102, an output platform 103, an atomic force microscope probe 104, and a quasi-zero stiffness mechanism 105;

[0031] Second implementation method:

[0032] Nano-pan-tilt head 201 with high static and low dynamic stiffness characteristics, base frame 202, output platform 203, atomic force microscope probe 204, quasi-zero stiffness mechanism 205, first mounting block 215, second mounting block 225, quasi-zero stiffness unit 235, positive stiffness mechanism 2135, negative stiffness mechanism 2235, first intersection a2, second intersection b2, third intersection c2, fourth intersection d2, flexible leaf spring member 206, hard spring member 207, driving assembly 208;

[0033] Third embodiment:

[0034] Nano-pan-tilt head 301 with high static and low dynamic stiffness characteristics, base frame 302, output platform 303, atomic force microscope probe 304, quasi-zero stiffness mechanism 305, first mounting block 315, second mounting block 325, quasi-zero stiffness unit 335, positive stiffness mechanism 3135, negative stiffness mechanism 3235, frame 32135, first frame intersection a3, second frame intersection b3, third frame intersection c3, fourth frame intersection d3, fifth frame intersection e3, flexible leaf spring member 306, hard spring member 307, driving assembly 308;

[0035] Fourth embodiment:

[0036] Nano-pan-tilt head 401 with high static and low dynamic stiffness characteristics, base frame 402, output platform 403, atomic force microscope probe 404, quasi-zero stiffness mechanism 405, first mounting block 415, second mounting block 425, quasi-zero stiffness unit 435, positive stiffness mechanism 4135, negative stiffness mechanism 4235, flexible leaf spring member 406, hard spring member 407, and driving assembly 408;

[0037] Fifth embodiment:

[0038] A nano pan-tilt head 501 with high static and low dynamic stiffness characteristics, a base frame 502, an output platform 503, an atomic force microscope probe 504, a quasi-zero stiffness mechanism 505, a first mounting block 515, a mounting groove 5515, a second mounting block 525, a quasi-zero stiffness unit 535, a positive stiffness mechanism 5135, a negative stiffness mechanism 5235, a flexible leaf spring component 506, a hard spring component 507, and a drive assembly 508. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The active / passive vibration suppression fusion nano-PTZ is a comprehensive vibration isolation platform that combines active and passive vibration isolation technologies. It is designed to provide more efficient and comprehensive vibration control to meet the stringent requirements of vibration-sensitive equipment or systems.

[0043] Specifically, active vibration isolation technology applies a certain control strategy to drive the actuator according to the detected vibration signal, so as to achieve the purpose of suppressing or eliminating vibration. Passive vibration isolation technology mainly utilizes material properties, such as using coil springs, vibration isolation rubber pads, air springs, etc. to isolate foundation vibration or isolate vibration sources, so that their vibration is not transmitted to the equipment or system. Although the structure used in passive vibration isolation technology is simpler, passive vibration isolation technology performs poorly in low-frequency resonance, has low vibration isolation performance, and requires a long stabilization time. The applicant proposes an active / passive vibration suppression fusion nano-pan-tilt that can combine the advantages of active vibration isolation technology and passive vibration isolation technology. Through the coordinated work of active vibration isolation technology and passive vibration isolation technology, it not only improves the vibration isolation efficiency, but also broadens the vibration isolation frequency range. This comprehensive platform can more effectively reduce the impact of vibration on equipment or systems, thereby improving working stability and overall performance. Specifically, the vibration isolation platform is an active-passive hybrid vibration isolation strategy improved by flexible nano-positioning technology. The system combines the high resolution, high force and frictionless characteristics of a piezoelectric actuator (PZT) with the high power and high speed characteristics of a voice coil motor (VCM) to improve vibration isolation performance.

[0044] However, the applicant also found that the inherent damping level of the system makes the vibration reduction effect in the resonance area poor. The traditional active / passive vibration suppression fusion nano-gimbal still mainly focuses on suppressing resonance by changing the damping of the system. Increasing damping weakens the characteristics of passive vibration isolation devices in suppressing vibration in the high-frequency band. The main function of increasing damping is to reduce vibration by consuming energy. This energy loss also means an increase in the effective mass of the system, which may lead to problems such as reduced system efficiency. These methods only focus on vibration suppression in the resonance area of ​​the system, and their high-frequency vibration suppression effects are subject to certain limitations. At the same time, although the design of the low-rigidity structure can reduce the natural frequency, it also makes it difficult to effectively suppress resonance. Faced with this challenge, how to improve the vibration isolation performance of the active / passive vibration suppression fusion nano-gimbal in the resonance area to optimize the overall vibration isolation effect has become the key to achieving higher precision for the nano-gimbal.

[0045] First embodiment

[0046] Figure 1 FIG. 1 shows a nano-pan-tilt platform 101 having high static and low dynamic stiffness characteristics according to the first embodiment of the present invention. Figure 1 It can be seen that the nano-pan-tilt platform 101 includes a base frame 102, an output platform 103, an atomic force microscope probe 104 and a quasi-zero stiffness mechanism 105. The output platform 103 is movably mounted on the base frame 102 along the vertical direction, and the atomic force microscope probe 104 is mounted on the output platform 103. The quasi-zero stiffness mechanism 105 includes a first mounting block, a second mounting block and a quasi-zero stiffness unit, and the quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block, the first mounting block is connected to the base frame 102, and the second mounting block is connected to the output platform 103.

[0047] A driving assembly is installed on the base frame 102, and the output end of the driving assembly is connected to the output platform 103 to drive the output platform 103 to move in the vertical direction relative to the base frame 102. The staff controls the movement of the driving assembly, the driving assembly drives the output platform 103 to move, and the output platform 103 drives the atomic force microscope probe 104 to move, thereby adjusting the distance between the atomic force microscope probe 104 and the observed object.

[0048] When the output platform 103 moves relative to the base, the output platform 103 will vibrate, and the vibration will be transmitted to the atomic force microscope probe 104. By setting the quasi-zero stiffness mechanism 105 between the output platform 103 and the base, the nano-pan-tilt platform 101 has the high static and low dynamic characteristics of "high static stiffness and low dynamic stiffness", and the vibration isolation performance and load-bearing capacity of the output platform 103 are improved.

[0049] The quasi-zero stiffness mechanism 105 may include one or more quasi-zero stiffness units. The number of quasi-zero stiffness units is not limited here.

[0050] The specific working principle of the quasi-zero stiffness mechanism 105 is: the first mounting block is fixedly connected to the base frame, the second mounting block is fixedly connected to the output platform 103, the quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism, the positive stiffness mechanism can apply a supporting force to the output platform 103, that is, the direction of the supporting force generated by the positive stiffness mechanism is parallel to the vertical direction and opposite to the direction of the gravity on the output platform 103, so the positive stiffness mechanism increases the bearing capacity and the static stiffness is maintained at a high level; the negative stiffness mechanism is arranged in the horizontal direction, and when the positive stiffness mechanism applies a supporting force to the output platform 103, the negative stiffness mechanism offsets the stiffness of the positive stiffness mechanism in the vertical direction, that is, the positive stiffness mechanism and the negative stiffness mechanism are connected in parallel, and its dynamic stiffness is close to zero. This means that the quasi-zero stiffness unit exhibits a strong bearing capacity when subjected to static loads, and exhibits a lower stiffness when facing dynamic loads, which is conducive to achieving vibration isolation and vibration reduction effects.

[0051] In the prior art, although there are studies and applications on the vibration reduction system of the negative stiffness mechanism, there is currently no solution to improve the performance of the active / passive vibration suppression fusion nano pan-tilt through the high static and low dynamic characteristics of the quasi-zero stiffness structure. The current active / passive vibration suppression fusion nano pan-tilt system has an inherent damping level, which makes the vibration reduction effect in the resonance area relatively low. The active / passive vibration suppression fusion nano pan-tilt will experience a sharp amplification of vibration energy in the resonance area. The passive vibration isolation structure usually has a fixed resonance frequency and damping characteristics. The performance of these structures in the resonance area will also be affected, thereby reducing their vibration isolation effect. In order to improve this problem, the present invention adds a quasi-zero stiffness mechanism 105 to the nano pan-tilt 101, and uses the quasi-zero stiffness mechanism 105 to significantly reduce the natural frequency of the nano pan-tilt 101, thereby achieving effective isolation of low-frequency vibrations.

[0052] See also Figure 2 The passive vibration isolation technology utilizes the characteristics of the quasi-zero stiffness mechanism 105, and the nano-pan-tilt platform 101 achieves better dynamic vibration isolation performance while maintaining a high static bearing capacity. Figure 2 It can be seen that after adding the quasi-zero stiffness mechanism 105 to the nano-pan platform 101, the nano-pan platform 101 has better effects in suppressing resonance and high-frequency vibration. In summary, the technical solution of adding the quasi-zero stiffness mechanism 105 realizes the decoupling of the bearing capacity and vibration isolation performance of the nano-pan platform 101, and also makes up for the defect that increasing damping will weaken the vibration suppression characteristics of the nano-pan platform 101 in the high frequency band.

[0053] Second embodiment

[0054] Figure 2 , Figure 3 and Figure 4 A second embodiment of the present invention is shown, in which components that are identical to or corresponding to those in the first embodiment are marked with corresponding figure numbers of the first embodiment. For example, in the first embodiment, the nano gimbal with high static and low dynamic stiffness characteristics is marked with 101, and in the second embodiment, the nano gimbal with high static and low dynamic stiffness characteristics is marked with 201, and other components are similar.

[0055] like Figure 3 Specifically, the first mounting block 215 and the second mounting block 225 are arranged in a vertical direction; see Figure 4The positive stiffness mechanism 2135 includes four positive stiffness elastic members connected end to end, the positive stiffness elastic members are connected and sequentially form a first intersection a2, a second intersection b2, a third intersection c2 and a fourth intersection d2, each positive stiffness elastic member can rotate relative to the corresponding intersection, for example, one end of a positive stiffness elastic member is located at the first intersection a2, and the other end is located at the second intersection b2, the positive stiffness elastic member can rotate relative to the first intersection a2, and can also rotate relative to the second intersection b2, so as to avoid damage to the positive stiffness elastic member due to the rigid connection at the intersection when bearing load; the negative stiffness mechanism 2235 includes a negative stiffness elastic member, one end of the negative stiffness elastic member is connected to the first intersection a2, and the other end of the negative stiffness elastic member is connected to the third intersection c2, and the line between the first intersection a2 and the third intersection c2 is parallel to the horizontal direction; the second intersection b2 is fixed to the first mounting block 215, and the fourth intersection d2 is fixed to the second mounting block 225.

[0056] See also Figure 4 , the principle of this structure: the negative stiffness elastic member and the positive stiffness elastic member will deform at the same time. When the four positive stiffness elastic members are deformed, the direction of the resultant force formed by the four positive stiffness elastic members is roughly parallel to the vertical direction and opposite to the load direction applied by the output platform 203 to the first mounting block 215, so the positive stiffness elastic member can provide the first mounting block 215 with a supporting force in the vertical direction. Since the negative stiffness elastic members are connected in parallel at the diagonal, the overall stiffness of the quasi-zero stiffness unit 235 will show a "quasi-zero" characteristic. Specifically, the atomic force microscope probe 204 has high precision, and the displacement magnitude of the output platform 203 is nanometer-level. Under the action of a small displacement load, the deformation of the quasi-zero stiffness unit 235 can be almost ignored. This characteristic enables the quasi-zero stiffness mechanism 205 to have a more outstanding vibration reduction effect in a low-frequency vibration environment.

[0057] See also Figure 4 In this embodiment, a 2x2 honeycomb cell linear array is formed by connecting a negative stiffness elastic member in parallel with a positive stiffness elastic member. This honeycomb structure has higher strength and stiffness than solid materials of the same weight, which makes the honeycomb quasi-zero stiffness structure show better durability and service life when subjected to impact and vibration.

[0058] See also Figure 4 Furthermore, the line between the first intersection a2 and the third intersection c2 is perpendicular to the vertical direction, and the four positive stiffness elastic members are symmetrical with respect to the vertical direction, and the force is more uniform.

[0059] See also Figure 4 Furthermore, the quasi-zero stiffness unit 235 is an integrated part, and the integrated processing eliminates the assembly clearance between the moving pairs in the traditional rigid mechanism, thereby achieving a friction-free and lubrication-free working state.

[0060] It should be emphasized that the honeycomb quasi-zero stiffness unit 235 is based on the principle of positive and negative stiffness in parallel, and can achieve low-frequency broadband vibration reduction. This means that it has a good suppression effect on vibrations of various frequencies, especially in low-frequency vibration environments. And although the structure has a quasi-zero stiffness characteristic, its load-bearing capacity is not affected, which enables the honeycomb quasi-zero stiffness unit 235 to maintain stable performance when bearing heavy loads.

[0061] See also Figure 2 and Figure 3 When applied to the nano pan-tilt 201, the driving component 208 drives the output platform 203 to move in the vertical direction, thereby driving the atomic force microscope probe 204 to move to adjust the distance between the atomic force microscope probe 204 and the observed object. The first mounting block 215 is fastened to the base frame 202 by screws, and the second mounting block 225 is fastened to the output platform 203 by screws. One or more honeycomb quasi-zero stiffness units 235 are arranged between the first mounting block 215 and the second mounting block 225. The combination of the quasi-zero stiffness mechanism 205 and the nano pan-tilt 201 with active / passive vibration suppression not only broadens the vibration isolation frequency band of the output platform 203, so that the output platform 203 can show good vibration isolation effect for vibrations of different frequencies, but also greatly improves the stability of the system through active and passive hybrid vibration isolation technology. Even in the case of active vibration isolation failure, the passive vibration isolation part, especially the honeycomb quasi-zero stiffness structure, can still effectively suppress vibration. Furthermore, the characteristics of the quasi-zero stiffness mechanism 205 and the high customizability of the honeycomb structure allow the stiffness of the nano-pan-tilt 201 to be flexibly adjusted. Finally, the lightweight and high-strength characteristics of the honeycomb structure reduce the overall weight while maintaining structural strength and stability, thereby helping to improve energy efficiency and overall operating performance.

[0062] See also Figure 3 Further, the nano-pan platform 201 further includes a hard spring member 207, one end of which is connected to the base frame 202, and the other end of which is connected to the output platform 203, and the hard spring member 207 is used to apply elastic force in the vertical direction to the output platform 203. The hard spring member 207 is symmetrically arranged on the left and right sides of the output platform 203, and the hard spring member 207 can be a coil spring, and the hard spring member 207 can offset the gravity of the output platform 203 and the atomic force microscope probe 204.

[0063] See also Figure 3Furthermore, the nano-pan-tilt platform 201 further includes a flexible leaf spring 206, one end of which is connected to the base frame 202, and the other end of which is connected to the output platform 203, and the flexible leaf spring 206 is used to apply elastic force in the vertical direction to the output platform 203. Specifically, the flexible leaf spring 206 is an S-shaped spring, and compared with the hard spring 207, the flexible leaf spring 206 has greater flexibility, and the flexible leaf spring 206 can be used as a passive vibration isolation device for vibration reduction.

[0064] Third embodiment

[0065] Figure 2 , Figure 5 and Figure 6 The third embodiment of the present invention is shown, in which the components that are the same as or corresponding to those in the first and second embodiments are marked with corresponding figure marks of the first and second embodiments. For example, in the first embodiment, the nano-pan head with high static and low dynamic stiffness characteristics is marked as 101, and in the second embodiment, the nano-pan head with high static and low dynamic stiffness characteristics is marked as 201. In the third embodiment, the nano-pan head with high static and low dynamic stiffness characteristics is marked as 301, and other components are similar.

[0066] like Figure 5 Specifically, the first mounting block 315 and the second mounting block 325 are arranged in a vertical direction; see Figure 6 The quasi-zero stiffness unit 335 includes a frame 32135, and the frame 32135 includes four trusses connected end to end, and two adjacent trusses can be rotatably arranged, that is, the four trusses are connected end to end to form a closed quadrilateral, and the quadrilateral has four frame intersections and two diagonals. The two adjacent sides of the quadrilateral can rotate relative to the frame intersections, and the first frame intersection a3 and the third frame intersection c3 are connected to form a diagonal, and the second frame intersection b3 and the fourth frame intersection d3 are connected to form another diagonal; the positive stiffness mechanism 3135 includes a positive stiffness elastic member, and the positive stiffness elastic member is arranged at a diagonal of the frame 32135, that is, one of the positive stiffness elastic members. One end of the positive stiffness elastic member is hinged to the first frame intersection a3 of the frame 32135, and the other end of the positive stiffness elastic member is hinged to the third frame intersection c3 of the frame 32135. The first frame intersection a3 is connected to the first mounting block 315, and the third frame intersection c3 is connected to the second mounting block 325; the negative stiffness mechanism 3235 includes a negative stiffness elastic member, and the negative stiffness elastic member is arranged at another diagonal line of the frame 32135, that is, one end of the negative stiffness elastic member is hinged to the second frame intersection b3 of the frame 32135, and the other end of the negative stiffness elastic member is hinged to the fourth frame intersection d3 of the frame 32135; the positive stiffness elastic member is parallel to the vertical direction, and the negative stiffness elastic member is parallel to the horizontal direction.

[0067] like Figure 6 As shown, the quasi-zero stiffness unit 335 of this embodiment is an X-shaped quasi-zero stiffness structure. By connecting the positive stiffness elastic member and the negative stiffness elastic member in parallel through the frame 32135, the lightweight design of the structure can be achieved while ensuring the overall structural performance. This can not only reduce the use of materials and reduce production costs, but also improve the dynamic performance of the structure. In addition, this quasi-zero stiffness structure exhibits unique performance near the static equilibrium position: its dynamic stiffness is close to zero, while the static stiffness is maintained at a high level. This means that the structure exhibits a strong bearing capacity when subjected to static loads, and exhibits a lower stiffness when facing dynamic loads, which is conducive to achieving vibration isolation and vibration reduction effects.

[0068] like Figure 6 As shown, the specific working principle is: this X-shaped structure connects a positive stiffness elastic member and a negative stiffness elastic member in parallel through the frame 32135. The positive stiffness elastic member is a vertically arranged spring, and the negative stiffness elastic member is a horizontally arranged spring. The two springs are arranged diagonally in the frame 32135, thereby constructing an overall structure with quasi-zero stiffness characteristics. When an external load acts on the quasi-zero stiffness mechanism 305, the horizontal spring and the vertical spring will deform at the same time. Figure 2 As shown, due to the existence of the horizontal spring as the negative stiffness mechanism 3135, the overall stiffness of the structure exhibits a "quasi-zero" characteristic, that is, under the action of a small amplitude load, the deformation of the structure is almost negligible. This characteristic enables the X-type quasi-zero stiffness mechanism 305 to have an excellent vibration reduction effect in a low-frequency vibration environment.

[0069] like Figure 6 As shown, when applied to the nano pan-tilt 301, the first mounting block 315 is fastened to the base frame 302 by screws, the second mounting block 325 is fastened to the output platform 303 by screws, and the driving assembly 308 drives the output platform 303 to move in the vertical direction, thereby driving the atomic force microscope probe 304 to move to adjust the distance between the atomic force microscope probe 304 and the observed object. One or more X-shaped quasi-zero stiffness mechanisms 305 are arranged between the first mounting block 315 and the second mounting block 325. The combination of the quasi-zero stiffness mechanism 305 and the nano pan-tilt with active / passive vibration suppression not only broadens the vibration isolation frequency band of the output platform 303, so that the output platform 303 can show good vibration isolation effect for vibrations of different frequencies, but also greatly improves the stability of the system through active and passive hybrid vibration isolation technology. Even in the case of active vibration isolation failure, the passive vibration isolation part, especially the X-shaped quasi-zero stiffness mechanism 305, can still effectively suppress vibration.

[0070] like Figure 6As shown, further, different diagonal lines of the frame 32135 intersect to form the fifth frame intersection e3; there are two positive stiffness elastic members, one is arranged between the first frame intersection a3 and the fifth frame intersection e3, and the other is arranged between the third frame intersection c3 and the fifth frame intersection e3; there are two negative stiffness elastic members, one is arranged between the second frame intersection b3 and the fifth frame intersection e3, and the other is arranged between the fourth frame intersection d3 and the fifth frame intersection e3. Accordingly, each positive stiffness spring can rotate relative to the fifth frame intersection e3, and each negative stiffness spring can rotate relative to the fifth frame intersection e3.

[0071] like Figure 6 As shown, further, the nano-pan-tilt platform 301 with high static and low dynamic stiffness characteristics also includes a hard spring member 307, one end of the hard spring member 307 is connected to the base frame 302, and the other end of the hard spring member 307 is connected to the output platform 303, and the hard spring member 307 is used to apply elastic force in the vertical direction to the output platform 303. The hard spring member 307 is symmetrically arranged on the left and right sides of the output platform 303, and the hard spring member 307 can be a coil spring, and the hard spring member 307 can offset the gravity of the output platform 303 and the atomic force microscope probe 304.

[0072] Furthermore, the nano-pan-tilt platform 301 with high static and low dynamic stiffness characteristics further includes a flexible leaf spring 306, one end of which is connected to the base frame 302, and the other end of which is connected to the output platform 303, and the flexible leaf spring 306 is used to apply elastic force in the vertical direction to the output platform 303. Specifically, the flexible leaf spring 306 is an S-shaped spring, and compared with the hard spring 307, the flexible leaf spring 306 has greater flexibility, and the flexible leaf spring 306 can be used as a passive vibration isolation device for vibration reduction.

[0073] Fourth embodiment

[0074] Figure 2 , Figure 7 and Figure 8 The fourth embodiment of the present invention is shown, in which the components that are the same as or corresponding to those in the first, second and third embodiments are marked with corresponding figure marks of the first, second and third embodiments. For example, in the first embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 101, in the second embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 201, in the third embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 301, and in the fourth embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 401, and other components are similar.

[0075] like Figure 7As shown, further, the first mounting block 415 and the second mounting block 425 are arranged in a horizontal direction; see Figure 8 The positive stiffness mechanism 4135 includes a flexible leaf spring member 406, one end of which is connected to the first mounting block 415, and the other end of which is connected to the second mounting block 425. The flexible leaf spring member 406 deflects and deforms to apply an elastic force in the vertical direction; the negative stiffness mechanism 4235 includes a horizontally arranged negative stiffness elastic member, one end of which is connected to the first mounting block 415, and the other end of which is connected to the second mounting block 425. The negative stiffness elastic member is arranged parallel to the horizontal direction.

[0076] like Figure 7 As shown, specifically, the quasi-zero stiffness mechanism 405 includes two, the second mounting block 425 of one quasi-zero stiffness mechanism 405 is fixed on the left side of the output platform 403, and its first mounting block 415 is fixed on the left side of the base frame and arranged in the horizontal direction with the second mounting block 425; the second mounting block 425 of the other quasi-zero stiffness mechanism 405 is fixed on the right side of the output platform 403, and its first mounting block 415 is fixedly installed on the right side of the base frame and arranged in the horizontal direction with the second mounting block 425.

[0077] like Figure 7 and Figure 8 As shown, when applied to the nano pan-tilt 401 with high static and low dynamic stiffness characteristics, the first mounting block 415 is fastened to the base frame 402 by screws, the second mounting block 425 is fastened to the output platform 403 by screws, and the drive assembly 408 drives the output platform 403 to move in the vertical direction, thereby driving the atomic force microscope probe 404 to move to adjust the distance between the atomic force microscope probe 404 and the observed object. The flexible leaf spring member 406 is designed in a way that the leaf spring hinge is connected in series end to end, and multiple leaf springs are arranged roughly in a horizontal direction. The flexible leaf spring member 406 deflects and deforms to apply elastic force in the vertical direction, and the flexible leaf spring member 406 can improve the bearing capacity. The flexible leaf spring member 406 with positive stiffness characteristics is combined in parallel with the negative stiffness elastic member with negative stiffness characteristics, so as to achieve the effect of dynamic stiffness close to or equal to zero at the static equilibrium position. The reasonable combination of the positive stiffness mechanism 4135 and the negative stiffness mechanism 4235 can achieve lightweight design while ensuring the overall structural performance.

[0078] The flexible leaf spring member 406 can be processed in an integrated manner, requiring only a small amount of assembly, thereby reducing production costs. The design of the leaf spring hinge in series at both ends utilizes the deformation of the flexible leaf spring member 406 to achieve movement and force transmission, rather than simply relying on a rigid connection, which reduces unnecessary material usage.

[0079] The difference between this embodiment and the above-mentioned embodiment 2 and embodiment 3 is that the flexible leaf spring member 306 in the above-mentioned embodiment 2 and embodiment 3 is merged into the quasi-zero stiffness unit 435, instead of being separately arranged between the output platform 403 and the base frame 402, which helps to reduce material consumption and production costs, while improving the dynamic performance of the structure.

[0080] like Figure 7 As shown, further, the nano pan-tilt platform 401 further includes a hard spring member 407, one end of the hard spring member 407 is connected to the base frame 402, and the other end of the hard spring member 407 is connected to the output platform 403, and the hard spring member 407 is used to apply elastic force in the vertical direction to the output platform 403. The hard spring member 407 is symmetrically arranged on the left and right sides of the output platform 403, and the hard spring member 407 can be a coil spring, and the hard spring member 407 can offset the gravity of the output platform 403 and the atomic force microscope probe 404.

[0081] Fifth embodiment

[0082] Figure 2 , Fig. 9 and Fig.10 The fifth embodiment of the present invention is shown, in which the components that are identical or corresponding to those in the first, second, third and fourth embodiments are marked with corresponding figure marks of the first, second, third and fourth embodiments. For example, in the first embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 101, in the second embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 201, in the third embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 301, in the fourth embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 401, and in the fifth embodiment, the figure mark of the nano-pan head with high static and low dynamic stiffness characteristics is 501, and other components are similar.

[0083] like Fig. 9 As shown, further, the first mounting block 515 and the second mounting block 525 are arranged in a vertical direction; see Fig.10The first mounting block 515 has a mounting groove 5515, and the second mounting block 525 is movably arranged in the mounting groove 5515 along the vertical direction; the positive stiffness mechanism 5135 includes a positive stiffness elastic member, one end of the positive stiffness elastic member is connected to the bottom wall of the mounting groove 5515, and the other end of the positive stiffness elastic member is connected to the top wall of the second mounting block 525; the negative stiffness mechanism 5235 includes a negative stiffness elastic member, and there are multiple negative stiffness elastic members arranged at intervals around the first mounting block 515, one end of each negative stiffness elastic member is connected to the groove peripheral wall of the mounting groove 5515, and the other end of each negative stiffness elastic member is on the side peripheral wall of the second mounting block 525; the extension lines of the negative stiffness elastic members intersect on the straight line where the positive stiffness elastic member is located.

[0084] See also Fig.10 When applied to the nano pan-tilt head 501, the first mounting block 515 is fastened to the base frame 502 by screws, the second mounting block 525 is fastened to the output platform 503 by screws, and the driving component 508 drives the output platform 503 to move in the vertical direction, thereby driving the atomic force microscope probe 504 to move to adjust the distance between the atomic force microscope probe 504 and the observed object.

[0085] See also Fig.10 In this embodiment, the quasi-zero stiffness unit 435 constructs an overall structure with quasi-zero stiffness characteristics by combining symmetrically arranged negative stiffness elastic members as negative stiffness mechanisms 5235 and vertically arranged positive stiffness elastic members as positive stiffness mechanisms 5135 in parallel. The principle of this structure is: the vertically arranged positive stiffness elastic members are used to carry the output platform 503 and the atomic force microscope probe 504, and the horizontally arranged negative stiffness elastic members are used to offset the stiffness of the positive stiffness compression springs, so that the stiffness of the output platform 503 at the static equilibrium position tends to zero. This quasi-zero stiffness mechanism 505 has high static stiffness and low dynamic stiffness characteristics. The high static stiffness improves the bearing capacity of the quasi-zero stiffness structure and reduces the static displacement; the low dynamic stiffness reduces the natural frequency of the output platform 503, and obtains a wider vibration isolation frequency band than a linear vibration isolator.

[0086] See also Fig. 9 Further, the nano-pan platform 501 further includes a hard spring member 507, one end of which is connected to the base frame 502, and the other end of which is connected to the output platform 503, and the hard spring member 507 is used to apply elastic force in the vertical direction to the output platform 503. The hard spring member 507 is symmetrically arranged on the left and right sides of the output platform 503, and the hard spring member 507 can be a coil spring, and the hard spring member 507 can offset the gravity of the output platform 503 and the atomic force microscope probe 504.

[0087] See also Fig. 9Further, the nano-pan-tilt platform 501 further includes a flexible leaf spring 506, one end of which is connected to the base frame 502, and the other end of which is connected to the output platform 503, and the flexible leaf spring 506 is used to apply elastic force in the vertical direction to the output platform 503. Specifically, the flexible leaf spring 506 is an S-shaped spring, and compared with the hard spring 507, the flexible leaf spring 506 has greater flexibility, and the flexible leaf spring 506 can be used as a passive vibration isolation device for vibration reduction.

[0088] The other components and operations of the nano-pan-tilt with high static and low dynamic stiffness characteristics according to the embodiment of the present invention are known to those of ordinary skill in the art and will not be described in detail here. In the description of the present invention, "first feature" and "second feature" may include one or more of these features. Among them, the up-down direction, left-right direction and front-back direction shall be based on the up-down direction, left-right direction and front-back direction shown in the figure.

[0089] In the description of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0091] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A nano pan-tilt head with high static and low dynamic stiffness, characterized in that: include: Scaffolding; An output platform, the output platform is movably mounted on the base frame along a vertical direction; an atomic force microscope probe, wherein the atomic force microscope probe is mounted on the output platform; A quasi-zero stiffness mechanism, comprising a first mounting block, a second mounting block and a quasi-zero stiffness unit, wherein the quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block, the first mounting block is used to connect the base frame, and the second mounting block is used to connect the output platform; The quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism, wherein the positive stiffness mechanism is used to apply a supporting force to the output platform, and the negative stiffness mechanism is arranged in a horizontal direction and is configured to offset the stiffness of the positive stiffness mechanism in the vertical direction when the positive stiffness mechanism applies a supporting force to the output platform.

2. The nano pan / tilt head with high static and low dynamic stiffness characteristics according to claim 1, characterized in that: The first mounting block and the second mounting block are arranged in an aligned manner along the vertical direction; The positive stiffness mechanism comprises four positive stiffness elastic members connected end to end, the positive stiffness elastic members are connected and sequentially form a first intersection point, a second intersection point, a third intersection point and a fourth intersection point, and each of the positive stiffness elastic members is configured to rotate relative to an intersection point; The negative stiffness mechanism comprises a negative stiffness elastic member, one end of the negative stiffness elastic member is connected to the first intersection, the other end of the negative stiffness elastic member is connected to the third intersection, and a line between the first intersection and the third intersection is parallel to the horizontal direction; The second intersection point is arranged on the first installation block, and the fourth intersection point is arranged on the second installation block.

3. The nano pan / tilt head with high static and low dynamic stiffness characteristics according to claim 2, characterized in that: A line between the second intersection point and the fourth intersection point is parallel to the vertical direction.

4. The nano pan / tilt head with high static and low dynamic stiffness characteristics according to claim 2, characterized in that: The quasi-zero stiffness unit is an integrated part.

5. The nano pan / tilt head with high static and low dynamic stiffness characteristics according to claim 1, characterized in that: The first mounting block and the second mounting block are arranged in an aligned manner along the vertical direction; The quasi-zero stiffness unit comprises a frame, wherein the frame comprises four trusses connected end to end, and two adjacent trusses are rotatably arranged; The positive stiffness mechanism comprises a positive stiffness elastic member, the positive stiffness elastic member is arranged at a diagonal line of the frame, one end of the positive stiffness elastic member is hinged to a first frame intersection of the frame, the other end of the positive stiffness elastic member is hinged to a third frame intersection of the frame, the first frame intersection is connected to the first mounting block, and the third frame intersection is connected to the second mounting block; The negative stiffness mechanism comprises a negative stiffness elastic member, the negative stiffness elastic member is arranged at another diagonal line of the frame, one end of the negative stiffness elastic member is hinged to the second frame intersection of the frame, and the other end of the negative stiffness elastic member is hinged to the fourth frame intersection of the frame; The positive stiffness elastic member is arranged parallel to the vertical direction, and the negative stiffness elastic member is arranged parallel to the horizontal direction.

6. The nano pan-tilt head with high static and low dynamic stiffness characteristics according to claim 5, characterized in that: Different diagonals of the frame intersect to form a fifth frame intersection; There are two positive stiffness elastic members, one is arranged between the first frame intersection and the fifth frame intersection, and the other is arranged between the third frame intersection and the fifth frame intersection; There are two negative stiffness elastic members, one is arranged between the second frame intersection and the fifth frame intersection, and the other is arranged between the fourth frame intersection and the fifth frame intersection.

7. The nano pan-tilt head with high static and low dynamic stiffness characteristics according to any one of claims 1 to 6, characterized in that: It also includes a flexible leaf spring member, one end of which is connected to the base frame, and the other end of which is connected to the output platform. The flexible leaf spring member is used to apply elastic force in the vertical direction to the output platform.

8. The nano pan-tilt head with high static and low dynamic stiffness characteristics according to claim 1, characterized in that: The first mounting block and the second mounting block are arranged in parallel along the horizontal direction; The positive stiffness mechanism comprises a flexible leaf spring member, one end of the flexible leaf spring member is connected to the first mounting block, the other end of the flexible leaf spring member is connected to the second mounting block, and the flexible leaf spring member is deflected and deformed to apply an elastic force in the vertical direction; The negative stiffness mechanism comprises a negative stiffness elastic member, one end of which is connected to the first mounting block, and the other end of which is connected to the second mounting block.

9. The nano pan-tilt head with high static and low dynamic stiffness characteristics according to any one of claim 1, characterized in that: The first mounting block and the second mounting block are arranged in an aligned manner along the vertical direction; The first mounting block has a mounting groove therein, and the second mounting block is movably disposed in the mounting groove along a vertical direction; The positive stiffness mechanism comprises a positive stiffness elastic member, one end of the positive stiffness elastic member is connected to the bottom wall of the mounting slot, the other end of the positive stiffness elastic member is connected to the top wall of the second mounting block, and the bottom wall and the top wall are arranged opposite to each other in the vertical direction; The negative stiffness mechanism comprises a negative stiffness elastic member, wherein the negative stiffness elastic member is arranged in a plurality of intervals around the first mounting block, one end of each of the negative stiffness elastic members is connected to the groove peripheral wall of the mounting groove, and the other end of each of the negative stiffness elastic members is connected to the side peripheral wall of the second mounting block, and the groove peripheral wall and the side peripheral wall are arranged opposite to each other in the horizontal direction; The extension line of the negative stiffness elastic member intersects with the straight line where the positive stiffness elastic member is located.

10. The nano pan / tilt platform with high static and low dynamic stiffness characteristics according to any one of claims 1-6, 8-9, characterized in that: It also includes a hard spring component, one end of which is connected to the base frame, and the other end of which is connected to the output platform. The hard spring component is used to apply elastic force in the vertical direction to the output platform.

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