Stepless self-adaptive large-range load quasi-zero stiffness vibration isolation platform and use method

Abstract

The invention belongs to the technical field of vibration control and isolation, and discloses a stepless self-adaptive large-range load quasi-zero stiffness vibration isolation platform and a use method.The use method comprises the steps that the load and motion state is monitored in real time through a stepless variable load vibration isolation supporting leg binding force sensor and an acceleration sensor, and after being processed by a signal conditioning module, the load and motion state is output; the passive grading quasi-zero stiffness system and the electromagnetic constant force module are regulated and controlled by the semi-active controller, so that stepless self-adaptive adjustment of a large-range load is realized; the passive grading system provides stepped load bearing, the electromagnetic constant-force module realizes stepless adjustment in a hierarchy, and the passive grading system and the electromagnetic constant-force module are combined to cover a wide-area load demand; the linear bearing reduces friction, viscous damping consumes vibration energy, the quasi-zero stiffness vibration isolation characteristic can be effectively exerted, the vibration isolation effect is improved, the application range is widened, and the vibration isolation device is suitable for vibration isolation in various load scenes.

Description

Technical Field

[0001] This invention belongs to the field of vibration control and isolation technology, and relates to a quasi-zero stiffness vibration isolation platform with stepless adaptive wide-range load and its usage method. Background Technology

[0002] Vibration is ubiquitous in engineering and technology, often adversely affecting equipment and personnel. To mitigate these effects, vibration isolation platforms are typically needed to isolate the vibration source from the equipment and personnel. Quasi-zero stiffness vibration isolation platforms are passive vibration isolation devices that balance low stiffness with load-bearing capacity. Their design philosophy is to achieve excellent vibration isolation performance in the low-frequency range. Compared to traditional linear isolators, quasi-zero stiffness isolation systems operate with extremely low natural frequencies near the zero-stiffness region, significantly improving the isolation effect against low-frequency vibrations. This makes them particularly suitable for applications such as precision equipment, high-end sensors, and spacecraft attitude control platforms. However, existing quasi-zero stiffness isolators are mostly passively designed, with non-adjustable loads, typically achieving quasi-zero stiffness only under specific loads. If the mass of the isolated object changes (e.g., due to load changes or altered operating conditions), the isolation system deviates from its optimal operating point, leading to increased system stiffness, a significant decrease in vibration isolation performance, and potentially period-doubling and chaotic phenomena.

[0003] To address this issue, existing research has attempted to introduce adjustable structures (such as multiple quasi-zero stiffness systems connected in series) to extend the load adaptation range. However, these methods are mostly graded adjustments, requiring fixed load variations, resulting in complex structures and difficulty in achieving stepless, real-time adjustment. They are particularly unsuitable for situations with randomly varying load magnitudes or large load variations. Furthermore, some studies have introduced active control technologies (such as using electromagnetic actuators) to enhance the intelligence and adaptability of vibration isolation systems. However, active systems suffer from high power consumption, complex control systems, and limited operational stability, making large-scale deployment in equipment requiring high reliability and long-term operation difficult. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of existing quasi-zero stiffness vibration isolators, such as unadjustable load or limited adjustment methods, high power consumption, complex systems, and limited stability in active control technology, which make it difficult to adapt to load changes. This invention provides a stepless adaptive quasi-zero stiffness vibration isolation platform and its usage method for a wide range of loads.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A quasi-zero stiffness vibration isolation platform with stepless adaptive wide-range load includes: an upper platform, a lower platform, stepless variable load vibration isolation legs, a force sensor, an acceleration sensor, a signal conditioning module, and a semi-active controller.

[0007] The continuously variable load vibration isolation leg is installed in the upper and lower platforms; the accelerometer is installed on the upper platform to measure the acceleration generated by the external force on the upper platform; the force sensor is installed on the side of the upper platform that contacts the continuously variable load vibration isolation leg, and the force sensor is used to measure the external force on the upper platform; the signal conditioning module is connected to the force sensor and the accelerometer; the semi-active controller is connected to the signal conditioning module and the semi-active controller is connected to the continuously variable load leg.

[0008] A further improvement of the present invention is that:

[0009] Furthermore, the continuously variable load vibration isolation leg includes: a passive graded quasi-zero stiffness system and an electromagnetic constant force module; the passive graded quasi-zero stiffness system includes: a guide rod, an upper linear bearing, a permanent magnet array frame, a magnetic array, a lower linear bearing, and an elastic system; the magnetic array includes several magnetic structures; the several magnetic structures are fixed to the permanent magnet array frame from top to bottom; the magnetic structures are annular; the upper and lower linear bearings are sleeved on the guide rod; the upper linear bearing is located at the annulus of the first magnetic structure; the lower linear bearing is located at the annulus of the last magnetic structure; both the upper and lower linear bearings are fixedly connected to the permanent magnet array frame; one end of the guide rod passes through the upper platform; and the guide rod is fixed to the upper platform by a first stop ring; the elastic system is set on the guide rod, and when the upper platform is compressed downward by an external force, the elastic system is used to generate a restoring force; the electromagnetic constant force module is fixedly connected to the permanent magnet array frame.

[0010] Furthermore, the elastic system includes a linear spring and a second stop ring; the linear spring is sleeved on the guide rod; the second stop ring is fixed to the guide rod; one end of the linear spring is disposed at the upper linear bearing; the other end of the linear spring is fixed to the second stop ring; when the guide rod moves downward, the guide rod moves through the upper and lower linear bearings, while the upper and lower linear bearings remain stationary; a first linear bearing is disposed between the first stop ring and the guide rod; the first linear bearing is used to reduce the friction between the upper platform and the guide rod.

[0011] Furthermore, the magnetic structure is fixed to the permanent magnet array frame by angle brackets, the angle brackets being "L"-shaped; the magnetic structure includes an upper cover plate, a fixing ring, an outer magnetic ring, and a lower cover plate; one end of the fixing ring, the upper cover plate, the lower cover plate, and the angle brackets is fixed to each other by bolt holes; the other end of the angle brackets is fixed to the permanent magnet array frame; the outer magnetic ring and the fixing ring are disposed between the upper cover plate and the lower cover plate, the fixing ring being used to restrict the radial movement of the outer magnetic ring, keeping the outer magnetic ring at the axis of the fixing ring; the upper cover plate and the lower cover plate being used to restrict the axial movement of the outer magnetic ring.

[0012] Furthermore, the electromagnetic constant force module includes a fixed outer shell, several coils, and a lower permanent magnet; the several coils are arranged sequentially from top to bottom inside the fixed outer shell; the guide rod passes through one end of the fixed outer shell, and the lower permanent magnet is fixed to one end of the guide rod; the magnetic array also includes an inner magnetic ring; the inner magnetic ring is arranged between two stop rings and thus fixed to the guide rod.

[0013] Furthermore, the semi-active controller includes a DC power supply module and a digital circuit module; the DC power supply module is used to provide current Ir to the electromagnetic constant force mechanism; the digital circuit is used to switch the positive and negative of the input current of the coils in layers i and i+1, so that the coils generate constant force in different layers to counteract the load mass; each pair of adjacent coils and the lower permanent magnet form a layer of electromagnetic constant force mechanism.

[0014] Furthermore, the coil includes an irregularly shaped coil frame and an irregularly shaped coil; the irregularly shaped coil is sleeved on the irregularly shaped coil frame; after a pair of irregularly shaped coils are energized, they generate a magnetic field that acts on the lower permanent magnet to produce a constant force. When the current is positive, the constant force is upward; when the current is negative, the constant force is downward; the upper linear bearing, the lower linear bearing, and the magnetic array are all fixed on the permanent magnet array frame, and the axes of the three are all on the same straight line; the upper and lower linear bearings provide a guiding effect for the guide rod, so that the guide rod is kept in a linear motion at the axis of the permanent magnet array frame; the upper and lower linear bearings are coated with viscous grease; when the upper platform moves relative to the lower platform, the guide rod moves relative to the first linear bearing; the first linear bearing generates a viscous damping force on the guide rod, consuming the energy generated by the vibration of the upper platform.

[0015] Furthermore, the magnetic array provides discontinuous negative stiffness; the linear spring provides positive stiffness, and the magnetic array's negative stiffness is connected in parallel to form a discontinuous quasi-zero stiffness region and a stepped restoring force. The center of the quasi-zero stiffness region is the center of two adjacent magnetic structures; each quasi-zero stiffness region bears a different load, and the load variation values ​​for each layer and the interlayer load are:

[0016]

[0017] In the formula, multiple magnetic structures and linear springs connected in parallel generate a stepped magnetic force, with each step bearing a load of M. i ; i is the number of layers in the permanent magnet array when the inner magnetic ring is in the quasi-zero stiffness region, k is the linear spring stiffness, dis is the spacing of the magnetic structures, and g is the gravitational acceleration.

[0018] A method for using a stepless adaptive quasi-zero stiffness vibration isolation platform with a wide load range includes: when the upper platform moves downward under external force, the pressure on the upper platform acts on a force sensor; the guide rod moves through the upper and lower linear bearings, while the upper and lower linear bearings remain stationary; the guide rod stretches a linear spring fixed at one end, which in turn drives the inner magnetic ring and lower permanent magnet fixed on the guide rod to move downward; when the upper platform moves upward, the pressure on the upper platform acts on the force sensor; the guide rod passes through the upper linear bearing and the lower linear shaft... The upper platform moves by compressing a linear spring fixed to one end of the guide rod, which in turn drives the inner magnetic ring and lower permanent magnet fixed to the guide rod to move upward. When the upper platform moves, the force sensor and acceleration sensor send the collected force information and motion information of the upper platform to the signal conditioning module. The signal conditioning module processes the received signal to obtain the load mass m. The semi-active controller sends the switching signals i, i+1 to the digital circuit and the current signal of the DC power supply according to the load mass m, so that the load switches between different layers to achieve a wide range of stepless load change.

[0019] Furthermore, the signal conditioning module processes the signal to provide the load quality m. The semi-active controller, based on the load quality m, provides the switching signals i, i+1 to the digital circuit and the current signal from the DC power supply, enabling the load to switch between different layers and achieve stepless load switching. The load quality is provided by the switching signal and the current signal, respectively:

[0020]

[0021] σ=sgn(I c b = (i-1)dis

[0022]

[0023] In the formula, m is the load mass, and F sa The force signal is given by the force sensor, g is the acceleration due to gravity, and a is the acceleration due to gravity. sa Let be the acceleration signal, i be the i-th layer of the electromagnetic constant force mechanism, ΔM be half of the stepped load between the layers of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, k be the stiffness of the linear spring, and F be the acceleration signal. ECFM The magnetic force provided by the electromagnetic constant force mechanism under the reference current of 1A, σ is the positive and negative switch with values ​​of +1 and -1, b is the equilibrium position of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, and Ir is the output current signal;

[0024] The magnetic array, inner magnetic ring and linear spring constitute a quasi-zero stiffness vibration isolator with load grading, used to adjust the load in stages, with a grading size of 2ΔM.

[0025] Each pair of adjacent coils and the lower permanent magnet form an electromagnetic constant force mechanism, and each layer of electromagnetic constant force mechanism corresponds to the layer of the quasi-zero stiffness vibration isolator with load grading.

[0026] The electromagnetic constant force module is used to realize the adjustment within the graded load and to realize the stepless adjustment within the quasi-zero stiffness vibration isolator level, with an adjustment range of [-ΔM, ΔM].

[0027] The maximum adjustable load of the electromagnetic constant force module in layer i of the continuously variable load isolation leg is M. i +ΔM; The minimum load of layer i+1 is M. i+1 -ΔM; where M i+1 =M i +2ΔM, M i The load is adjusted in stages for layer i; the load adjustment between two layers is connected, thus achieving stepless load adjustment within multiple layers.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention utilizes stepless variable load vibration isolation legs combined with force sensors and acceleration sensors to monitor load and motion status in real time. After signal conditioning, a semi-active controller regulates a passive graded quasi-zero stiffness system and an electromagnetic constant force module to achieve stepless adaptive adjustment of a wide range of loads. The passive graded system provides stepped load bearing, while the electromagnetic constant force module enables stepless adjustment within each grade. The combination of the two covers a wide range of load requirements. Linear bearings reduce friction, and viscous damping dissipates vibration energy. This invention can effectively leverage the quasi-zero stiffness vibration isolation characteristics, improve vibration isolation effect and applicability, and is suitable for vibration isolation in various load scenarios. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a quasi-zero stiffness vibration isolation platform with stepless adaptive wide-range load according to the present invention.

[0032] Figure 2 This is a schematic diagram of the stepless variable load vibration isolation support leg of the present invention;

[0033] Figure 3 This is a schematic diagram of the magnetic array of the present invention;

[0034] Figure 4 This is a schematic diagram of the magnetic structure of the present invention;

[0035] Figure 5 This is a schematic diagram of the electromagnetic constant force module of the present invention;

[0036] Figure 6 This is a schematic diagram of the coil of the present invention;

[0037] Figure 7 This is a schematic diagram of the control system of the present invention;

[0038] Figure 8 This is a schematic diagram of the mechanical curves of the present invention;

[0039] Figure 9 This is a schematic diagram of the digital circuit of the present invention.

[0040] Among them, 1-upper platform, 2-accelerometer, 3-first stop ring, 4-first linear bearing, 5-force sensor, 6-stepless variable load vibration isolation leg, 7-lower platform, 8-signal conditioning module, 9-semi-active controller, 60-guide rod, 61-upper linear bearing, 62-permanent magnet array frame, 63-linear spring, 64-second stop ring, 65-angle code, 66-magnetic array, 67-lower linear bearing, 68-electromagnetic constant force module. 661-First magnetic structure, 662-Inner magnetic ring, 663-Second magnetic structure, 664-Third magnetic structure, 665-Fourth magnetic structure, 666-Upper cover plate, 667-Fixing ring, 668-Outer magnetic ring, 669-Lower cover plate, 681-First coil, 682-Lower permanent magnet, 683-Second coil, 684-Third coil, 685-Fourth coil, 686-Fixing outer shell, 687-Irregularly shaped coil frame, 688-Irregularly shaped coil. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0045] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0046] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0047] The present invention will now be described in further detail with reference to the accompanying drawings:

[0048] See Figure 1 This invention discloses a quasi-zero stiffness vibration isolation platform with stepless adaptive wide-range load, comprising: an upper platform 1, a lower platform 7, stepless variable load vibration isolation legs 6, a force sensor 5, an acceleration sensor 2, a signal conditioning module 8, and a semi-active controller 9.

[0049] The continuously variable load vibration isolation leg 6 is installed in the upper platform 1 and the lower platform 7; the accelerometer 2 is installed on the upper platform 1 and is used to measure the acceleration generated by the external force on the upper platform 1; the force sensor 5 is installed on the side of the upper platform 1 that contacts the continuously variable load vibration isolation leg 6 and is used to measure the external force on the upper platform 1; the signal conditioning module 8 is connected to the force sensor 5 and the accelerometer 2; the semi-active controller 9 is connected to the signal conditioning module 8 and is connected to the continuously variable load vibration isolation leg 6.

[0050] See Figure 2 The infinitely variable load vibration isolation leg 6 includes: a passive graded quasi-zero stiffness system and an electromagnetic constant force module 68; the passive graded quasi-zero stiffness system includes: a guide rod 60, an upper linear bearing 61, a permanent magnet array frame 62, a magnetic array 66, a lower linear bearing 67, and an elastic system; see also Figure 3 The magnetic array 66 includes a first magnetic structure 661, a second magnetic structure 663, a third magnetic structure 664, and a fourth magnetic structure 665; the first magnetic structure 661, the second magnetic structure 663, the third magnetic structure 664, and the fourth magnetic structure 665 are fixed sequentially from top to bottom on the permanent magnet array frame 62; the first magnetic structure 661, the second magnetic structure 663, the third magnetic structure 664, and the fourth magnetic structure 664 are all annular; the upper linear bearing 61 and the lower linear bearing 67 are sleeved on the guide rod 60; the upper linear bearing 61... Bearing 61 is located at the ring of the first magnetic structure; the lower linear bearing 67 is located at the ring of the last magnetic structure; both the upper linear bearing 61 and the lower linear bearing 67 are fixedly connected to the permanent magnet array frame 62; one end of the guide rod 60 passes through the upper platform 1; and the guide rod 60 is fixed to the upper platform 1 by the first stop ring 3; the elastic system is set on the guide rod 60, and when the upper platform 1 is compressed downward by an external force, the elastic system is used to generate a restoring force; the electromagnetic constant force module 68 is fixedly connected to the permanent magnet array frame 62.

[0051] The elastic system includes a linear spring 63 and a second stop ring 64; the linear spring 63 is sleeved on the guide rod 60; the second stop ring 64 is fixed to the guide rod 60; one end of the linear spring 63 is disposed at the upper linear bearing 61; the other end of the linear spring 63 is fixed to the second stop ring 64; when the guide rod 60 moves downward, the guide rod 60 moves through the upper linear bearing 61 and the lower linear bearing 67, while the upper linear bearing 61 and the lower linear bearing 67 remain stationary; a first linear bearing 4 is disposed between the first stop ring 3 and the guide rod 60; the first linear bearing 4 is used to reduce the friction between the upper platform 1 and the guide rod 60.

[0052] The magnetic structure is fixed to the permanent magnet array frame 62 by angle brackets 65, which are "L"-shaped; see also Figure 4The magnetic structure includes an upper cover plate 666, a fixing ring 667, an outer magnetic ring 668, and a lower cover plate 669. One end of the fixing ring 667, the upper cover plate 666, the lower cover plate 669, and the corner bracket 65 are fixed to each other through bolt holes. The other end of the corner bracket 65 is fixed to the permanent magnet array frame 62. The outer magnetic ring 668 and the fixing ring 667 are disposed between the upper cover plate 666 and the lower cover plate 669. The fixing ring 667 is used to restrict the radial movement of the outer magnetic ring 668, so that the outer magnetic ring 668 is kept at the axis of the fixing ring 667. The upper cover plate 666 and the lower cover plate 669 are used to restrict the axial movement of the outer magnetic ring 668.

[0053] See Figure 5 The electromagnetic constant force module 68 includes a fixed housing 686, a first coil 681, a second coil 683, a third coil 684, a fourth coil 685, and a lower permanent magnet 682. The first coil 681, the second coil 683, the third coil 684, and the fourth coil 685 are arranged sequentially from top to bottom inside the fixed housing 686. The guide rod 60 passes through one end of the fixed housing 686, and the lower permanent magnet 682 is fixed to one end of the guide rod 60. The magnetic array 66 also includes an inner magnetic ring 662. The inner magnetic ring 662 is arranged between two stop rings and thus fixed to the guide rod 60.

[0054] The semi-active controller 9 includes a DC power supply module and a digital circuit module; the DC power supply module is used to provide current Ir to the electromagnetic constant force mechanism; the digital circuit is used to switch the positive and negative of the input current of the coils in layers i and i+1, so that the coils generate constant force in different layers to offset the load mass; each pair of adjacent coils and the lower permanent magnet 682 form an electromagnetic constant force mechanism.

[0055] See Figure 6 The coil includes an irregularly shaped coil frame 687 and an irregularly shaped coil 688; the irregularly shaped coil 688 is sleeved on the irregularly shaped coil frame 687; after a pair of irregularly shaped coils 688 are energized, they generate a magnetic field that acts on the lower permanent magnet 682 to produce a constant force. When the current is positive, the constant force is upward; when the current is negative, the constant force is downward. The upper linear bearing 61, the lower linear bearing 67, and the magnetic array 66 are all fixed on the permanent magnet array frame 62, and the axes of the three are all on the same straight line. The upper linear bearing 61 and the lower linear bearing 67 provide a guiding effect for the guide rod 60, so that the guide rod 60 is kept in a linear motion along the axis of the permanent magnet array frame 62. The upper linear bearing 61 and the lower linear bearing 67 are coated with viscous grease. When the upper platform 1 moves relative to the lower platform 7, the guide rod 60 moves relative to the first linear bearing 4. The first linear bearing 4 generates a viscous damping force on the guide rod 60, which consumes the energy generated by the vibration of the upper platform 1.

[0056] The magnetic array 66 provides discontinuous negative stiffness; the linear spring 63 provides positive stiffness, and the negative stiffness of the magnetic array 66 is connected in parallel to form a discontinuous quasi-zero stiffness region and a stepped restoring force. The center of the quasi-zero stiffness region is the center of two adjacent magnetic structures; each quasi-zero stiffness region bears a different load, and the load variation values ​​for each layer and the interlayer load are:

[0057]

[0058] In this system, multiple magnetic structures and linear springs connected in parallel generate a stepped magnetic force, with each step bearing a load of M. i i represents the number of layers in the permanent magnet array when the inner magnetic ring 662 is in the quasi-zero stiffness region, k represents the linear spring stiffness, dis represents the spacing of the magnetic structures, and g represents the gravitational acceleration.

[0059] A method for using a stepless adaptive quasi-zero stiffness vibration isolation platform with a wide load range includes: when the upper platform 1 moves downward under external force, the pressure on the upper platform 1 acts on the force sensor 5; the guide rod 60 moves through the upper linear bearing 61 and the lower linear bearing 67, while the upper linear bearing 61 and the lower linear bearing 67 remain stationary; the guide rod 60 stretches a linear spring 63 fixed at one end, which in turn drives the inner magnetic ring 662 and the lower permanent magnet 682 fixed on the guide rod 60 to move downward; when the upper platform 1 moves upward, the pressure on the upper platform 1 acts on the force sensor 5; the guide rod 60 moves through the upper linear bearing 61 and the lower linear bearing 67, compressing the linear spring 63 fixed at one end, which in turn drives the inner magnetic ring 662 and the lower permanent magnet 682 fixed on the guide rod 60 to move upward; see also Figure 7 When the upper platform 1 moves, the force sensor 5 and the acceleration sensor 2 send the collected force information and motion information of the upper platform 1 to the signal conditioning module 8. The signal conditioning module 8 processes the received signal to obtain the load mass m. The semi-active controller 9 sends the switching signals i, i+1 of the digital circuit and the current signal of the DC power supply according to the load mass m, so that the load switches between different layers to achieve a wide range of stepless load change.

[0060] Signal conditioning module 8 processes the signal and provides the load quality m. Semi-active controller 9, based on the load quality m, provides the switching signals i and i+1 to the digital circuit and the current signal from the DC power supply, enabling the load to switch between different layers and achieve stepless load switching. The load quality is provided by the switching signal and the current signal, respectively:

[0061]

[0062] σ=sgn(I c b = (i-1)dis

[0063]

[0064] In the formula, m is the load mass, and F sa The force signal is given by the force sensor, g is the acceleration due to gravity, and a is the acceleration due to gravity. sa Let be the acceleration signal, i be the i-th layer of the electromagnetic constant force mechanism, ΔM be half of the stepped load between the layers of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, k be the stiffness of the linear spring, and F be the acceleration signal. ECFM The magnetic force provided by the electromagnetic constant force mechanism under a reference current of 1A, σ is the positive and negative switch with values ​​of +1 and -1, b is the equilibrium position of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, and I r The output current signal is m0; m0 is the initial mass of the platform when it is at quasi-zero stiffness in the first layer; I c To offset the current required by the load, the current source in the controller provides a current of magnitude I. r , among which, I c =I r *σ.

[0065] See Figure 9 In digital circuit i, i+1 is used to turn on switch S. i S i+1 Turn on the i-th and i+1-th coils to keep them connected; the i-th and i+1-th coils and the inner magnetic ring 662 form the i-th electromagnetic constant force mechanism.

[0066] σ is used to change the positive and negative directions of the input current S+1 and S-1; where S+1 is fully open, it is a positive current, and S-1 is fully open, it is a negative current.

[0067] Because the number of levels in the graded quasi-zero stiffness system composed of the magnetic structure, inner magnetic ring 662, and linear spring 63 corresponds to the number of levels in the electromagnetic constant force module. That is, the first magnetic structure 661, the second magnetic structure 663, the inner magnetic ring 662, and the linear spring 63 generate the first layer of quasi-zero stiffness region. When the inner magnetic ring 662 is located in the first layer of quasi-zero stiffness region, the force exerted by the first coil 681 and the second coil 683 on the lower permanent magnet 682 is a constant force. The lower permanent magnet 682 is located at the center of the first coil 681 and the second coil 683, and the three together form the first layer of electromagnetic constant force structure. The remaining quasi-zero stiffness levels and electromagnetic constant force levels correspond one-to-one as described above.

[0068] The magnetic array 66, the inner magnetic ring 662 and the linear spring 63 form a quasi-zero stiffness vibration isolator with load grading, which is used to adjust the load in stages, with a grading size of 2ΔM.

[0069] Each pair of adjacent coils and the lower permanent magnet 682 form an electromagnetic constant force mechanism, and each layer of electromagnetic constant force mechanism corresponds to the layer of the quasi-zero stiffness vibration isolator with load grading.

[0070] The electromagnetic constant force module 68 is used to realize the adjustment within the graded load and to realize the stepless adjustment within the quasi-zero stiffness vibration isolator level, with an adjustment range of [-ΔM, ΔM].

[0071] The maximum adjustable load of the electromagnetic constant force module 68 in the i-th layer of the continuously variable load isolation leg 6 is M. i +ΔM; The minimum load of layer i+1 is M. i+1 -ΔM; where M i+1 =M i +2ΔM, M i The load is tiered and adjustable at level i; the adjustable loads between two levels are interconnected, thus achieving stepless load adjustment across multiple levels. See also Figure 8 In each layer of the electromagnetic constant force mechanism, the load can be infinitely adjusted [-ΔM, ΔM] according to the different input current load variations. When the current source is given at its maximum value Icm, the load-bearing capacity of the quasi-zero stiffness region changes due to the digital circuit altering the direction of the input current. In the first layer, when the circuit is 0, the load is M0; when the circuit is negative, the load is minimum, becoming M0-ΔM; when the circuit is positive, the load is maximum, becoming M0+ΔM. In the second layer, when the circuit is 0, the load is M0+2ΔM; when the circuit is negative, the load is minimum, becoming M0+ΔM; when the circuit is positive, the load is maximum, becoming M0+3ΔM. In the third layer, when the circuit is 0, the load is M0+4ΔM; when the circuit is negative, the load is minimum, becoming M0+3ΔM; when the circuit is positive, the load is maximum, becoming M0+5ΔM. The maximum load value in each layer is equal to the minimum load value in the next layer, and the maximum load value in this layer is equal to the minimum load value in the layer above, thus achieving infinitely variable load over a wide range.

[0072] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A quasi-zero stiffness vibration isolation platform with infinitely adaptive wide-range load, characterized in that, include: Upper platform (1), lower platform (7), stepless variable load vibration isolation leg (6), force sensor (5), acceleration sensor (2), signal conditioning module (8) and semi-active controller (9); The continuously variable load vibration isolation leg (6) is installed in the upper platform (1) and the lower platform (7); the accelerometer (2) is installed on the upper platform (1) and is used to measure the acceleration generated by the external force on the upper platform (1); the force sensor (5) is installed on the side of the upper platform (1) that contacts the continuously variable load vibration isolation leg (6) and is used to measure the external force on the upper platform (1); the signal conditioning module (8) is connected to the force sensor (5) and the accelerometer (2); the semi-active controller (9) is connected to the signal conditioning module (8) and is connected to the continuously variable load leg (6).

2. The quasi-zero stiffness vibration isolation platform with infinitely adaptive large-range load as described in claim 1, characterized in that, The continuously variable load vibration isolation leg (6) includes: a passive graded quasi-zero stiffness system and an electromagnetic constant force module (68); the passive graded quasi-zero stiffness system includes: a guide rod (60), an upper linear bearing (61), a permanent magnet array frame (62), a magnetic array (66), a lower linear bearing (67), and an elastic system; the magnetic array (66) includes several magnetic structures; the several magnetic structures are fixed to the permanent magnet array frame (62) from top to bottom; the magnetic structures are annular; the upper linear bearing (61) and the lower linear bearing (67) are sleeved on the guide rod (60); the upper linear bearing (61) is located at the ring of the first magnetic structure; the lower linear bearing (67) is located at the ring of the last magnetic structure; the upper linear bearing (61) and the lower linear bearing (67) are both fixedly connected to the permanent magnet array frame (62); one end of the guide rod (60) passes through the upper platform (1); and the guide rod (60) is fixed to the upper platform (1) by the first stop ring (3); the elastic system is set on the guide rod (60), and when the upper platform (1) is compressed downward by an external force, the elastic system is used to generate a restoring force; the electromagnetic constant force module (68) is fixedly connected to the permanent magnet array frame (62).

3. The stepless adaptive large-range load quasi-zero stiffness vibration isolation platform according to claim 2, characterized in that, The elastic system includes a linear spring (63) and a second stop ring (64); the linear spring (63) is sleeved on the guide rod (60); the second stop ring (64) is fixed on the guide rod (60); one end of the linear spring (63) is located at the upper linear bearing (61); the other end of the linear spring (63) is fixed on the second stop ring (64); when the guide rod (60) moves downward, the guide rod (60) moves through the upper linear bearing (61) and the lower linear bearing (67), while the upper linear bearing (61) and the lower linear bearing (67) remain stationary; a first linear bearing (4) is provided between the first stop ring (3) and the guide rod (60); the first linear bearing (4) is used to reduce the friction between the upper platform (1) and the guide rod (60).

4. The stepless adaptive large-range load quasi-zero stiffness vibration isolation platform according to claim 3, characterized in that, The magnetic structure is fixed to the permanent magnet array frame (62) by a bracket (65), which is "L" shaped. The magnetic structure includes an upper cover plate (666), a fixing ring (667), an outer magnetic ring (668), and a lower cover plate (669). One end of the fixing ring (667), the upper cover plate (666), the lower cover plate (669), and the bracket (65) are fixed to each other by bolt holes. The other end of the bracket (65) is fixed to the permanent magnet array frame (62). The outer magnetic ring (668) and the fixing ring (667) are arranged between the upper cover plate (666) and the lower cover plate (669). The fixing ring (667) is used to restrict the radial movement of the outer magnetic ring (668) so that the outer magnetic ring (668) is kept at the axis of the fixing ring (667). The upper cover plate (666) and the lower cover plate (669) are used to restrict the axial movement of the outer magnetic ring (668).

5. The stepless adaptive large-range load quasi-zero stiffness vibration isolation platform according to claim 4, characterized in that, The electromagnetic constant force module (68) includes a fixed housing (686), several coils, and a lower permanent magnet (682); the several coils are arranged sequentially from top to bottom inside the fixed housing (686); the guide rod (60) passes through one end of the fixed housing (686), and the lower permanent magnet (682) is fixed to one end of the guide rod (60); the magnetic array (66) also includes an inner magnetic ring (662); the inner magnetic ring (662) is arranged between two stop rings and then fixed on the guide rod (60).

6. The quasi-zero stiffness vibration isolation platform with stepless adaptive large-range load according to claim 5, characterized in that, The semi-active controller (9) includes a DC power supply module and a digital circuit module; the DC power supply module is used to provide current Ir to the electromagnetic constant force mechanism; the digital circuit is used to switch the positive and negative of the input current of the coils in layers i and i+1, so that the coils generate constant force in different layers to offset the load mass; each pair of adjacent coils and the lower permanent magnet (682) form a layer of electromagnetic constant force mechanism.

7. The stepless adaptive wide-range load quasi-zero stiffness vibration isolation platform according to claim 6, characterized in that, The coil includes an irregular coil frame (687) and an irregular coil (688); the irregular coil (688) is sleeved on the irregular coil frame (687); when a pair of irregular coils (688) are energized, they generate a magnetic field that acts on the lower permanent magnet (682) to produce a constant force. When the current is positive, the constant force is upward; when the current is negative, the constant force is downward; the upper linear bearing (61), the lower linear bearing (67), and the magnetic array (66) are all fixed on the permanent magnet array frame (62), and the axes of the three are all on the same straight line; the upper Linear bearing (61) and lower linear bearing (67) are used to provide a guiding effect for guide rod (60), so that guide rod (60) is kept in the axis of permanent magnet array frame (62) for linear motion; the upper linear bearing (61) and lower linear bearing (67) are coated with viscous grease; when the upper platform (1) moves relative to the lower platform (7), guide rod (60) moves relative to the first linear bearing (4); the first linear bearing (4) generates viscous damping force on guide rod (60) to consume the energy generated by the vibration of upper platform (1).

8. The stepless adaptive wide-range load quasi-zero stiffness vibration isolation platform according to claim 7, characterized in that, The magnetic array (66) is used to provide discontinuous negative stiffness; the linear spring (63) provides positive stiffness and the negative stiffness of the magnetic array (66) in parallel to form a discontinuous quasi-zero stiffness region and a stepped restoring force, the center of the quasi-zero stiffness region being the center of two adjacent magnetic structures; each quasi-zero stiffness region bears a different load, and the load variation values ​​for each layer and the interlayer load are: In the formula, multiple magnetic structures and linear springs connected in parallel generate a stepped magnetic force, with each step bearing a load of M. i ;i is the number of layers in the permanent magnet array when the inner magnetic ring (662) is in the quasi-zero stiffness region, k is the linear spring stiffness, dis is the spacing of the magnetic structure, and g is the gravitational acceleration.

9. A method for using a quasi-zero stiffness vibration isolation platform with infinitely adaptive wide-range loads, characterized in that, include: When the upper platform (1) moves downward under external force, the pressure on the upper platform (1) acts on the force sensor (5); the guide rod (60) moves through the upper linear bearing (61) and the lower linear bearing (67), while the upper linear bearing (61) and the lower linear bearing (67) remain stationary. The guide rod (60) stretches a linear spring (63) fixed at one end, and drives the inner magnetic ring (662) and the lower permanent magnet (682) fixed on the guide rod (60) to move downward; when the upper platform (1) moves upward, the pressure on the upper platform (1) acts on the force sensor (5); the guide rod (60) moves through the upper linear bearing (61) and the lower linear bearing (67) to move downward. During the motion, the guide rod (60) compresses a linear spring (63) fixed at one end on the guide rod, and drives the inner magnetic ring (662) and the lower permanent magnet (682) fixed on the guide rod (60) to move upward. When the upper platform (1) moves, the force sensor (5) and the acceleration sensor (2) send the force information and motion information of the upper platform (1) to the signal conditioning module (8). The signal conditioning module (8) processes the received signal to obtain the load mass m. The semi-active controller (9) sends the switching signals i, i+1 of the digital circuit and the current signal of the DC power supply to the load according to the load mass m, so that the load can switch between different layers to achieve a wide range of stepless load change.

10. The method of using the stepless adaptive large-range load quasi-zero stiffness vibration isolation platform according to claim 9, characterized in that, The signal conditioning module (8) processes the signal and provides the load quality m. The semi-active controller (9) provides the switching signals i, i+1 of the digital circuit and the current signal of the DC power supply according to the load quality m, so that the load can be switched at different levels to achieve stepless load change. The load quality is the switching signal and the current signal respectively: σ=sgn(I c ) b = (i-1)dis In the formula, m is the load mass, and F sa The force signal is given by the force sensor, g is the acceleration due to gravity, and a is the acceleration due to gravity. sa Let be the acceleration signal, i be the i-th layer of the electromagnetic constant force mechanism, ΔM be half of the stepped load between the layers of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, k be the stiffness of the linear spring, and F be the acceleration signal. ECFM The magnetic force provided by the electromagnetic constant force mechanism under the reference current of 1A, σ is the positive and negative switch with values ​​of +1 and -1, b is the equilibrium position of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, and Ir is the output current signal; The magnetic array (66), inner magnetic ring (662) and linear spring (63) constitute a quasi-zero stiffness vibration isolator with load grading, used for graded load adjustment, with a grading size of 2ΔM; Each pair of adjacent coils and the lower permanent magnet (682) form a layer of electromagnetic constant force mechanism, and each layer of electromagnetic constant force mechanism corresponds to the layer of the quasi-zero stiffness vibration isolator with load grading; The electromagnetic constant force module (68) is used to realize the adjustment within the graded load and to realize the stepless adjustment within the quasi-zero stiffness vibration isolator level. The adjustment range is [-ΔM, ΔM]. The maximum adjustable load of the electromagnetic constant force module (68) in the i-th layer of the continuously variable load isolation leg (6) is M. i +ΔM; The minimum load of layer i+1 is M. i+1 -ΔM; where M i+1 =M i +2ΔM, M i The load is adjusted in stages for layer i; the load adjustment between two layers is connected, thus achieving stepless load adjustment within multiple layers.

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