A quasi-zero stiffness vibration isolation platform with a large range of loads and a method of use

Abstract

The application belongs to the technical field of vibration control and isolation, and discloses a quasi-zero stiffness vibration isolation platform with a large range of load and a use method, which comprises the following steps: a variable load vibration isolation support leg is combined with a force sensor and an acceleration sensor to monitor the load and the motion state in real time, the passive hierarchical quasi-zero stiffness system and the electromagnetic constant force module are regulated by a semi-active controller after being processed by a signal conditioning module, and the large range of load is adaptively adjusted; the passive hierarchical system provides a stepped load bearing, the electromagnetic constant force module realizes the variable adjustment within the level, and the two are combined to cover the wide range of load requirements; the linear bearing reduces friction and the viscous damping consumes vibration energy, the application can effectively exert the quasi-zero stiffness vibration isolation characteristics, improve the vibration isolation effect and the application range, and is suitable for vibration isolation in various load scenes.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vibration control and isolation, and relates to a quasi-zero stiffness vibration isolation platform with poleless self-adaptive wide-range load and a use method. BACKGROUND

[0002] Vibration is ubiquitous in the field of engineering technology, and often brings adverse effects on equipment and personnel. In order to reduce the adverse effects caused by vibration, a vibration isolation platform is usually needed to isolate the influence of the vibration source on the equipment and personnel. The quasi-zero stiffness vibration isolation platform is a passive vibration isolation device that takes into account low stiffness and load capacity. Its design concept is to obtain excellent vibration isolation performance in the low frequency band. Compared with traditional linear vibration isolators, the quasi-zero stiffness vibration isolation system works in the near-zero stiffness region, and the system natural frequency is extremely low, thereby significantly improving the isolation effect of low-frequency vibration, and is particularly suitable for scenes such as precision equipment, high-end sensors and spacecraft attitude control platforms. However, the existing quasi-zero stiffness vibration isolators are designed in a passive manner, and their load is not adjustable, and they can only achieve quasi-zero stiffness under a specific load. Once the mass of the object to be isolated changes (for example, due to load replacement, change of running state, etc.), the vibration isolation system will deviate from the optimal operating point, causing the system stiffness to rise and the vibration isolation performance to decrease significantly, and in addition, it will also cause the period-doubling phenomenon and the chaos phenomenon.

[0003] In order to solve this problem, existing research attempts to introduce adjustable structures (such as multiple quasi-zero stiffness systems in series) to expand the load adaptation range, but these methods are mostly stepwise adjustment, require fixed load changes, have complex structures, and are difficult to achieve poleless and real-time adjustment, especially not suitable for situations where the load size changes randomly or the load change amplitude is large. In addition, some research introduces active control technology (such as using electromagnetic actuators) to improve the intelligence and adaptability of the vibration isolation system. However, the active system has high power consumption, a complex control system and limited stability, and is difficult to be widely promoted in equipment with high reliability and long-term operation. SUMMARY

[0004] The purpose of the present application is to solve the problems of the prior art, such as the quasi-zero stiffness vibration isolator having unadjustable load or limited adjustment method, the active control technology having high power consumption, a complex system and limited stability, and the difficulty in adapting to load changes, and to provide a quasi-zero stiffness vibration isolation platform with poleless self-adaptive wide-range load and a use method.

[0005] To achieve the above purpose, the technical scheme of the present application is as follows:

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

[0007] The non-constant load isolation leg is arranged in the upper platform and the lower platform; the acceleration sensor is arranged on the upper platform and is used for measuring the acceleration generated by the external force on the upper platform; the force sensor is arranged on the side of the upper platform in contact with the non-constant load isolation leg, and is used for measuring the external force on the upper platform; the signal conditioning module is connected with the force sensor and the acceleration sensor; the semi-active controller is connected with the signal conditioning module, and the semi-active controller is connected with the non-constant load leg.

[0008] Further improvements of the present application are:

[0009] Further, the non-constant load isolation leg comprises a passive hierarchical quasi-zero stiffness system and an electromagnetic constant force module; the passive hierarchical quasi-zero stiffness system comprises 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 comprises a plurality of magnetic structures; the plurality of magnetic structures are sequentially fixed on the permanent magnet array frame from top to bottom; the magnetic structure is circular; the upper linear bearing and the lower linear bearing are sleeved on the guide rod; the upper linear bearing is located at the circular ring of the first magnetic structure; the lower linear bearing is located at the circular ring of the last magnetic structure; the upper linear bearing and the lower linear bearing are fixedly connected with the permanent magnet array frame; one end of the guide rod penetrates through the upper platform; and the guide rod is fixed with the upper platform through a first stop ring; the elastic system is arranged on the guide rod, and is used for generating a restoring force when the upper platform is compressed downward by an external force; the electromagnetic constant force module is fixedly connected with the permanent magnet array frame.

[0010] Further, the elastic system comprises a linear spring and a second stop ring; the linear spring is sleeved on the guide rod; the second stop ring is fixed on the guide rod; one end of the linear spring is arranged at the upper linear bearing; the other end of the linear spring is fixed on the second stop ring; when the guide rod moves downward, the guide rod moves through the upper linear bearing and the lower linear bearing, and the upper linear bearing and the lower linear bearing remain stationary; a first linear bearing is arranged between the first stop ring and the guide rod; the first linear bearing is used for reducing the friction between the upper platform and the guide rod.

[0011] Further, the magnetic structure is fixed on the permanent magnet array frame through an angle code, and the angle code is "L" shaped; the magnetic structure comprises an upper cover plate, a fixed ring, an outer magnetic ring and a lower cover plate; the fixed ring, the upper cover plate, the lower cover plate and one end of the angle code are fixed with each other through bolt holes; the other end of the angle code is fixed on the permanent magnet array frame; the outer magnetic ring and the fixed ring are arranged between the upper cover plate and the lower cover plate, and the fixed ring is used for limiting the radial movement of the outer magnetic ring, so that the outer magnetic ring remains at the axis of the fixed ring; the upper cover plate and the lower cover plate are used for limiting the axial movement of the outer magnetic ring.

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

[0013] Further, the semi-active controller comprises a direct current power module and a digital circuit module; the direct current power 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 i and i+1 layers of coils, so that the coils generate constant force to offset the load mass in different layers; each adjacent two coils and the lower permanent magnet form a layer of electromagnetic constant force mechanism.

[0014] Further, the coil comprises a special-shaped coil frame and a special-shaped coil; the special-shaped coil is sleeved on the special-shaped coil frame; a pair of special-shaped coils generates a magnetic field after being electrified, which acts on the lower permanent magnet to generate a constant force; when the current is positive, the direction of the constant force is upward; when the current is negative, the direction of the constant force is downward; the upper linear bearing, the lower linear bearing and the magnetic array are all fixed on the permanent magnetic array frame, and the shaft centers of the three are on the same straight line; the upper linear bearing and the lower linear bearing are used to provide a guiding effect for the guide rod, so that the guide rod keeps straight line movement at the shaft center of the permanent magnetic array frame; the upper linear bearing and the lower linear bearing are coated with viscous lubricating 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 viscous damping force on the guide rod, which consumes the energy generated by the vibration of the upper platform.

[0015] Further, the magnetic array is used to provide discontinuous negative stiffness; the linear spring provides positive stiffness and magnetic array negative stiffness in parallel to form a non-continuous quasi-zero stiffness area and a stepped restoring force, and the center position of the quasi-zero stiffness area is the center position of two adjacent magnetic structures; each quasi-zero stiffness area bears different loads, and the load of each layer and the load change value between layers are:

[0016]

[0017] In the formula, a plurality of magnetic structures and linear springs are connected in parallel to generate a stepped magnetic force, and the load borne by each step is M i ; i is the number of layers of the permanent magnetic array when the inner magnetic ring is in the quasi-zero stiffness area, k is the linear spring stiffness, dis is the distance of the magnetic structure, and g is the acceleration of gravity.

[0018] The application relates to a method for using a quasi-zero stiffness vibration isolation platform with a pole self-adapting wide-range load, which comprises the following steps: when an upper platform moves downward under external force, pressure of the upper platform acts on a force sensor; a guide rod moves through upper and lower linear bearings, the upper and lower linear bearings remain stationary, a linear spring fixed at one end of the guide rod is stretched, and an inner magnetic ring and a lower permanent magnet fixed on the guide rod move downward; when the upper platform moves upward, pressure of the upper platform acts on the force sensor; the guide rod moves through the upper and lower linear bearings, the linear spring fixed at one end of the guide rod is compressed, and the inner magnetic ring and the lower permanent magnet fixed on the guide rod move upward; when the upper platform moves, the force sensor and an acceleration sensor send collected force information and motion information of the upper platform to a signal conditioning module; the signal conditioning module processes the received signals to obtain a load mass m, a semi-active controller gives a switching signal i, i+1 of a digital circuit and a current signal of a direct current power supply according to the load mass m, so that the load can be switched in different layers to realize wide-range poleless load change.

[0019] Further, the signal conditioning module processes signals to obtain the load mass m, and the semi-active controller gives the switching signal i, i+1 of the digital circuit and the current signal of the direct current power supply according to the load mass m, so that the load can be switched in different layers to realize poleless load change, and the load mass, the switching signal and the current signal are respectively as follows:

[0020]

[0021] sigma = sgn (I c ) b = (i-1)dis

[0022]

[0023] In the formula, m is the load mass, F sa is a force signal given by the force sensor, g is the gravity acceleration, a sa is an acceleration signal, i is an i-layer electromagnetic constant force mechanism, delta M is half of the stepped load between layers of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, k is the stiffness of the linear spring, F ECFM is a magnetic force provided by the electromagnetic constant force mechanism under a reference current 1A, sigma is a positive and negative switch, and the value is +1, -1, b is the equilibrium position of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, and Ir is an output current signal.

[0024] The magnetic array, the inner magnetic ring and the linear spring constitute a load-stepped quasi-zero stiffness vibration isolator for stepped adjustment of the load, and the layer size is 2delta M.

[0025] Each two adjacent coils and the lower permanent magnet constitute a layer of electromagnetic constant force mechanism, and each layer of electromagnetic constant force mechanism corresponds to a level of the load graded quasi-zero stiffness vibration isolator;

[0026] The electromagnetic constant force module is used for realizing adjustment within the graded load, realizing infinite adjustment within the level of the quasi-zero stiffness vibration isolator, and the adjustment range is [-△M, △M];

[0027] The maximum adjustment load of the electromagnetic constant force module of the i layer in the infinite variable load vibration isolation leg is M i +△M, and the minimum load of the i+1 layer is M i+1 -△M; wherein, M i+1 =M i +2△M, M i is the i layer graded adjustment load; the adjustment load between two layers realizes communication, so that the infinite adjustment load is realized within multiple layers.

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

[0029] The present application realizes infinite self-adaptive adjustment of a large range of load by combining the infinite variable load vibration isolation leg with force sensors and acceleration sensors to monitor the load and motion state in real time, processing the signals through a signal conditioning module, and regulating the passive graded quasi-zero stiffness system and the electromagnetic constant force module by a semi-active controller; the passive graded system provides a stepped load bearing, the electromagnetic constant force module realizes infinite adjustment within the level, and the two are combined to cover a wide range of load requirements; the linear bearing reduces friction and viscous damping to consume vibration energy, the present application can effectively exert the quasi-zero stiffness vibration isolation characteristics, improve the vibration isolation effect and application range, and is suitable for vibration isolation in various load scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the present application, and should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0031] Figure 1 It is a schematic diagram of a quasi-zero stiffness vibration isolation platform of the present application for infinite self-adaptive large range load;

[0032] Figure 2 It is a schematic diagram of the infinite variable load vibration isolation leg of the present application;

[0033] Figure 3 It is a schematic diagram of the magnetic array of the present application;

[0034] Figure 4 It is a schematic diagram of the magnetic structure of the present application;

[0035] Figure 5 Schematic diagram of electromagnetic constant force module of the present application;

[0036] Figure 6 Schematic diagram of coil of the present application;

[0037] Figure 7 Schematic diagram of control system of the present application;

[0038] Figure 8 Schematic diagram of mechanical curve of the present application;

[0039] Figure 9 Schematic diagram of digital circuit of the present application.

[0040] Wherein, 1-Upper platform, 2-Acceleration sensor, 3-First stop ring, 4-First linear bearing, 5-Force sensor, 6-Endless variable load vibration isolation leg, 7-Lower platform, 8-Signal conditioning module, 9-Half-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-Internal magnetic ring, 663-Second magnetic structure, 664-Third magnetic structure, 665-Fourth magnetic structure, 666-Upper cover plate, 667-Fixed ring, 668-External magnetic ring, 669-Lower cover plate, 681-First coil, 682-Lower permanent magnet, 683-Second coil, 684-Third coil, 685-Fourth coil, 686-Fixed shell, 687-Special-shaped coil frame, 688-Special-shaped coil. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0043] It should be noted that like reference numerals and letters refer to like items in the several views, and that no further definitions and explanations of such items are required in the subsequent drawings once such items have been defined in one of the drawings.

[0044] In the description of the embodiments of the present application, it should be noted that the orientation or position relationship indicated by the terms "upper", "lower", "horizontal", "inner" and the like is based on the orientation or position relationship shown in the drawings or the orientation or position relationship in which the product of the present application is usually placed, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0045] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0046] In the description of the embodiments of the present application, it should also be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] The present application will be described in further detail below in conjunction with the accompanying drawings:

[0048] Referring to Figure 1 The present application discloses a kind of quasi-zero stiffness vibration isolation platform of infinitely variable self-adaptive large range load, comprising: upper platform 1, lower platform 7, infinitely variable load vibration isolation leg 6, force sensor 5, acceleration sensor 2, signal conditioning module 8 and semi-active controller 9;

[0049] The infinitely variable load vibration isolation leg 6 is arranged in upper platform 1 and lower platform 7;The acceleration sensor 2 is arranged on the upper platform 1, for measuring the acceleration generated by the external force suffered by the upper platform 1;The force sensor 5 is arranged on the side of the upper platform 1 contacting the infinitely variable load vibration isolation leg 6, and the force sensor 5 is used to measure the external force suffered by the upper platform 1;The signal conditioning module 8 is connected to the force sensor 5 and the acceleration sensor 2;The semi-active controller 9 is connected to the signal conditioning module 8, and the semi-active controller 9 is connected to the infinitely variable load leg 6.

[0050] Referring to Figure 2 , the non-extreme variable load vibration isolation leg 6 comprises: a passive hierarchical quasi-zero stiffness system and an electromagnetic constant force module 68; the passive hierarchical quasi-zero stiffness system comprises: 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; referring to Figure 3 , the magnetic array 66 comprises 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 sequentially fixed on the permanent magnet array frame 62 from top to bottom; the first magnetic structure 661, the second magnetic structure 663, the third magnetic structure 664, and the fourth magnetic structure 665 are all circular rings; 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 circular ring of the first magnetic structure; the lower linear bearing 67 is located at the circular ring of the last magnetic structure; the upper linear bearing 61 and the lower linear bearing 67 are fixedly connected with 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 with the upper platform 1 through the first stop ring 3; the elastic system is arranged on the guide rod 60, and is used for generating a restoring force when the upper platform 1 is compressed downward by an external force; the electromagnetic constant force module 68 is fixedly connected with the permanent magnet array frame 62.

[0051] The elastic system comprises 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 arranged 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, and the upper linear bearing 61 and the lower linear bearing 67 remain stationary; a first linear bearing 4 is arranged 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 on the permanent magnet array frame 62 through an angle code 65, and the angle code 65 is "L" shaped; referring to Figure 4The magnetic structure comprises an upper cover plate 666, a fixed ring 667, an outer magnetic ring 668 and a lower cover plate 669; the fixed ring 667, the upper cover plate 666, the lower cover plate 669 and one end of the angle code 65 are fixed to each other through bolt holes; the other end of the angle code 65 is fixed on the permanent magnetic array frame 62; the outer magnetic ring 668 and the fixed ring 667 are arranged between the upper cover plate 666 and the lower cover plate 669, and the fixed ring 667 is used for limiting the radial movement of the outer magnetic ring 668, so that the outer magnetic ring 668 is kept at the axis of the fixed ring 667; the upper cover plate 666 and the lower cover plate 669 are used for limiting the axial movement of the outer magnetic ring 668.

[0053] Referring to Figure 5 The electromagnetic constant force module 68 comprises a fixed shell 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 sequentially arranged in the fixed shell 686 from top to bottom; one end of the guide rod 60 passes through the fixed shell 686, and the lower permanent magnet 682 is fixed at one end of the guide rod 60; the magnetic array 66 further comprises an inner magnetic ring 662; the inner magnetic ring 662 is arranged between two stop rings, and is then fixed on the guide rod 60.

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

[0055] Referring to Figure 6 The coil comprises a special-shaped coil frame 687 and a special-shaped coil 688; the special-shaped coil 688 is sleeved on the special-shaped coil frame 687; a pair of special-shaped coils 688 generate a magnetic field after being electrified, and the magnetic field acts on the lower permanent magnet 682 to generate a constant force; when the current is positive, the direction of the constant force is upward; when the current is negative, the direction of 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 magnetic array frame 62, and the axes of the three are on the same straight line; the upper linear bearing 61 and the lower linear bearing 67 are used for providing a guiding action for the guide rod 60, so that the guide rod 60 keeps at the axis of the permanent magnetic array frame 62 to move linearly; the upper linear bearing 61 and the lower linear bearing 67 are coated with viscous lubricating 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 viscous damping force on the guide rod 60, and consumes the energy generated by the vibration of the upper platform 1.

[0056] The magnetic array 66 is used to provide discontinuous negative stiffness; the linear spring 63 provides positive stiffness and the magnetic array 66 negative stiffness in parallel to form a discontinuous quasi-zero stiffness region and a stepped restoring force, the center position of the quasi-zero stiffness region is the center position of two adjacent magnetic structures; each quasi-zero stiffness region bears different loads, and the load of each layer and the load change value between layers are:

[0057]

[0058] Wherein, a plurality of magnetic structures and linear springs are connected in parallel to generate a stepped magnetic force, and each step bears a load M i ; i is the number of layers of 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.

[0059] A method for using a quasi-zero stiffness vibration isolation platform with an infinitely adaptive large range load, comprising: when the upper platform 1 is subjected to an external force and moves downward, 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, the upper linear bearing 61 and the lower linear bearing 67 remain stationary, the guide rod 60 stretches the linear spring 63 fixed at one end of the guide rod, 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, the guide rod 60 compresses the linear spring 63 fixed at one end of 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; see 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 signals to obtain the load mass m, and the semi-active controller 9 gives 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 can be switched between different layers to realize infinitely variable load.

[0060] The signal conditioning module 8 processes the signal to give the load mass m, and the semi-active controller 9 gives 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 can be switched between different layers to realize infinitely variable load, and the load mass is

[0061]

[0062] σ=sgn(I c )b=(i-1)dis

[0063]

[0064] Wherein, m is the load mass, F sa is the force signal given by the force sensor, g is the gravity acceleration, a sa is the acceleration signal, i is the i-th layer of the electromagnetic constant force mechanism, ΔM is half of the stepped load between the passive magnetic multi-stage quasi-zero stiffness vibration isolator layers, k is the stiffness of the linear spring, F ECFM is the magnetic force provided by the electromagnetic constant force mechanism under the reference current IA, σ is the positive and negative switch, with a value of +1, -1, b is the equilibrium position of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, I r is the output current signal; m0 is the initial mass of the platform when it is in the first layer of quasi-zero stiffness; I c is the current needed to offset the load, the current given by the current source in the controller is I r , wherein I c = I r * σ.

[0065] Referring to Figure 9 , the digital circuits i, i+1 are used to open the switches S i , S i+1 . The i, i+1 coils are turned on to keep the path; the i, i+1 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; wherein S+1 is fully open for positive current, and S-1 is fully open for negative current.

[0067] Because the number of levels in the stepped quasi-zero stiffness composed of the magnetic structure, the inner magnetic ring 662 and the linear spring 63 corresponds to the number of levels of 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 forces of the first coil 681 and the second coil 683 on the lower permanent magnet 682 are constant forces, and the lower permanent magnet 682 is located at the center position of the first coil 681 and the second coil 683, which form the first layer of electromagnetic constant force structure. The rest of the quasi-zero stiffness levels and the electromagnetic constant force levels are one-to-one corresponding as described above.

[0068] The magnetic array 66, the inner magnetic ring 662 and the linear spring 63 form a load stepped quasi-zero stiffness vibration isolator for stepped adjustment of the load, and the level size is 2△M;

[0069] Each adjacent two 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 a level of the load stepped quasi-zero stiffness vibration isolator;

[0070] The electromagnetic constant force module 68 is used to realize the adjustment within the hierarchical load, realize the infinite adjustment within the quasi-zero stiffness vibration isolator level, and the adjustment range is [-△M, △M];

[0071] The maximum adjustment load of the electromagnetic constant force module 68 of the i layer in the infinite variable load vibration isolation leg 6 is M i The minimum load of the i+1 layer is M i+1 -△M; wherein M i+1 =M i +2△M, M i is the hierarchical adjustment load of the i layer; the adjustment load between two layers realizes communication, so as to realize the infinite adjustment load in multiple layers. Referring to Figure 8 , the electromagnetic constant force mechanism in each layer changes according to different input current load, and the load can realize [-△M, △M] infinite adjustment in each layer according to the size of the current. When the current of the current source is given as the maximum Icm, the carrying capacity of the quasi-zero stiffness area changes due to the change of the input current direction of the digital circuit. In the first layer, when the circuit is 0, the load is M0; when the circuit is negative, the load is minimum, which becomes M0-△M; when the circuit is positive, the load is maximum, which becomes M0+△M. In the second layer, when the circuit is 0, the load is M0+2△M; when the circuit is negative, the load is minimum, which becomes M0+△M; when the circuit is positive, the load is maximum, which becomes M0+3△M. In the third layer, when the circuit is 0, the load is M0+4△M; when the circuit is negative, the load is minimum, which becomes M0+3△M; when the circuit is positive, the load is maximum, which becomes M0+5△M. The maximum load of each layer is equal to the minimum load of the next layer, and the maximum load of this layer is equal to the minimum load of the upper layer, so as to realize a large range of infinite variable load.

[0072] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A quasi-zero stiffness vibration isolation platform for pole self-adaptive wide range load, characterized in that, The utility model relates to a kind of vibration isolation platform, including: Upper platform (1), lower platform (7), infinitely variable load vibration isolation leg (6), force sensor (5), acceleration sensor (2), signal conditioning module (8) and semi-active controller (9); The infinitely variable load vibration isolation leg (6) is arranged in upper platform (1) and lower platform (7);The acceleration sensor (2) is arranged on the upper platform (1), for measuring the acceleration generated by the external force suffered by the upper platform (1);The force sensor (5) is arranged on the side of the upper platform (1) contacting the infinitely variable load vibration isolation leg (6), and the force sensor (5) is used to measure the external force suffered by the upper platform (1);The signal conditioning module (8) is connected to the force sensor (5) and the acceleration sensor (2);The semi-active controller (9) is connected to the signal conditioning module (8), and the semi-active controller (9) is connected to the infinitely variable load leg (6); The infinitely variable load vibration isolation leg (6) comprises a passive hierarchical quasi-zero stiffness system and an electromagnetic constant force module (68);The passive hierarchical quasi-zero stiffness system comprises 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) comprises a plurality of magnetic structures;The plurality of magnetic structures are sequentially fixed on the permanent magnet array frame (62) from top to bottom;The magnetic structure is circular ring-shaped;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 circular ring of the first magnetic structure;The lower linear bearing (67) is located at the circular ring of the last magnetic structure;The upper linear bearing (61) and the lower linear bearing (67) are fixedly connected with the permanent magnet array frame (62);One end of the guide rod (60) penetrates through the upper platform (1);And the guide rod (60) is fixed with the upper platform (1) through the first stop ring (3);The elastic system is arranged on the guide rod (60), and when the upper platform (1) is compressed downward by external force, the elastic system is used to generate restoring force;The electromagnetic constant force module (68) is fixedly connected with the permanent magnet array frame (62); The elastic system comprises 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 arranged 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), and the upper linear bearing (61) and the lower linear bearing (67) remain stationary;A first linear bearing (4) is arranged 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); The magnetic structure is fixed on the permanent magnet array frame (62) through an angle code (65), the angle code (65) is "L" shaped; the magnetic structure comprises an upper cover plate (666), a fixing ring (667), an outer magnetic ring (668) and a lower cover plate (669); the fixing ring (667), the upper cover plate (666), the lower cover plate (669) and one end of the angle code (65) are fixed with each other through bolt holes; the other end of the angle code (65) is fixed on 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 for limiting 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 for limiting the axial movement of the outer magnetic ring (668); The electromagnetic constant force module (68) comprises a fixed shell (686), a plurality of coils and a lower permanent magnet (682); the plurality of coils are sequentially arranged in the fixed shell (686) from top to bottom; the guide rod (60) passes through one end of the fixed shell (686), and the lower permanent magnet (682) is fixed on one end of the guide rod (60); the magnetic array (66) further comprises an inner magnetic ring (662); the inner magnetic ring (662) is arranged between two stop rings, and is further fixed on the guide rod (60); The semi-active controller (9) comprises a direct current power module and a digital circuit module; the direct current power module is used for providing current Ir for the electromagnetic constant force mechanism; the digital circuit is used for switching the positive and negative of the input current of the i and i+1 layers of coils, so that the coils generate constant force to offset the load mass in different layers; every two adjacent coils and the lower permanent magnet (682) form a layer of electromagnetic constant force mechanism.

2. The quasi-zero stiffness vibration isolation platform for pole adaptive large range loads of claim 1, wherein, The coil comprises a special-shaped coil frame (687) and a special-shaped coil (688); the special-shaped coil (688) is sleeved on the special-shaped coil frame (687); a pair of special-shaped coils (688) generate a magnetic field after being electrified, and the magnetic field acts on the lower permanent magnet (682) to generate constant force; when the current is positive, the direction of the constant force is upward; when the current is negative, the direction of 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 on the same straight line; the upper linear bearing (61) and the lower linear bearing (67) are used for providing a guiding effect for the guide rod (60), so that the guide rod (60) keeps at the axis of the permanent magnet array frame (62) to move linearly; the upper linear bearing (61) and the lower linear bearing (67) are coated with viscous lubricating 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 viscous damping force on the guide rod (60), and consumes the energy generated by the vibration of the upper platform (1).

3. The quasi-zero stiffness vibration isolation platform for pole adaptive large range loads of claim 2, wherein, The magnetic array (66) is used for providing discontinuous negative stiffness; the linear spring (63) provides positive stiffness and the magnetic array (66) negative stiffness in parallel to form a discontinuous quasi-zero stiffness area and a stepped restoring force, and the center position of the quasi-zero stiffness area is the center position of two adjacent magnetic structures; each quasi-zero stiffness area bears different loads, and the load of each layer and the load change value between layers are: In the formula, the plurality of magnetic structures and linear springs are connected in parallel to generate a stepped magnetic force, and each step bears a load of ; i is the number of layers of the permanent magnet array when the inner magnetic ring (662) is in the quasi-zero stiffness region, k is the stiffness of the linear spring, dis is the spacing of the magnetic structure, g is the acceleration of gravity, is half of the stepped load between the layers of the passive magnetic multi-stage quasi-zero stiffness vibration isolator.

4. A method of using the quasi-zero stiffness vibration isolation platform of claim 3 for a wide range of loads with no pole self-adaptation, characterized in that, Comprise: When the upper platform (1) is subjected to external force and moves downward, the pressure of 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), the upper linear bearing (61) and the lower linear bearing (67) remain stationary, the linear spring (63) fixed at one end of the guide rod is stretched, and the inner magnetic ring (662) and the lower permanent magnet (682) fixed on the guide rod (60) are driven to move downward; when the upper platform (1) moves upward, the pressure of 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), the guide rod (60) compresses the linear spring (63) fixed at one end of the guide rod, and the inner magnetic ring (662) and the lower permanent magnet (682) fixed on the guide rod (60) are driven to move upward; when the upper platform (1) moves, the force sensor (5) and the acceleration sensor (2) send the collected force information and the 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, and the semi-active controller (9) gives the switching signal 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 can be switched in different layers to realize large-range stepless variable load.

5. The method of using the quasi-zero stiffness vibration isolation platform for pole- changing self-adaptive wide-range loads according to claim 4, characterized in that, The signal conditioning module (8) processes the signal to give the load mass m, and the semi-active controller (9) gives the switching signal 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 can be switched in different layers to realize stepless variable load, and the load mass is: where m is the load mass, is the force signal given by the force sensor, g is the gravity acceleration, is the acceleration signal, i is the i-th layer electromagnetic constant force mechanism, is half of the stepped load between the passive magnetic multi-stage quasi-zero stiffness vibration isolator layers, k is the stiffness of the linear spring, is the magnetic force provided by the electromagnetic constant force mechanism under the reference current 1A, is the positive and negative switch, the value is +1, -1, b is the equilibrium position of the passive magnetic multi-stage quasi-zero stiffness vibration isolator, Ir is the output current signal; The magnetic array (66), the inner magnetic ring (662) and the linear spring (63) form a load grading quasi-zero stiffness vibration isolator, which is used for grading adjusting load, and the level size is 2△M; Each adjacent two 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 level of the load grading quasi-zero stiffness vibration isolator; The electromagnetic constant force module (68) is used for adjusting within the grading load, realizing stepless adjustment within the level of the quasi-zero stiffness vibration isolator, and the adjustment range is [-△M, △M]; The maximum adjustment load of the electromagnetic constant force module (68) of the i layer in the non-polar variable load vibration isolation leg (6) is ; the minimum load of the i+1 layer is ; wherein, , is the layer grading adjustment load; the adjustment load between the two layers is connected, so as to realize the non-polar adjustment load in multiple layers.

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