Variable load adaptive vibration isolator with frequency-dependent damping characteristic and vibration-stabilized platform

Abstract

This invention belongs to the technical field of vibration control equipment and discloses a variable load adaptive vibration isolator with frequency-varying damping characteristics. It includes a first cylinder, a second cylinder, an isolation unit, and a sensing unit. The first and second cylinders are connected at their respective port positions to form an inner cavity for assembling the isolation unit. The isolation unit includes a first piston, a first spring, a second piston, and a second spring arranged coaxially. The first spring is sleeved on the first piston, with one end abutting against the first cylinder and in a compressed state. The second spring is sleeved on the second piston, with one end abutting against the second cylinder and in a compressed state. A float is connected to one end of the second piston via multiple parallel frequency-varying damping springs. An annular boss is fixed on the second chamber, opposite to a guide bearing. A deformable damping sealing membrane connects the annular boss and the second piston. The float and the annular boss cooperate to form a frequency-varying damping structure. This invention effectively suppresses resonance while preventing the deterioration of high-frequency vibration isolation.

Description

Technical Field

[0001] This invention belongs to the field of vibration control equipment technology, and more specifically, relates to a variable load adaptive vibration isolator and a vibration reduction and attitude stabilization platform with frequency-varying damping characteristics. Background Technology

[0002] For existing airborne and sea-based equipment, commonly used vibration reduction systems include three types: purely passive control, semi-active control, and a combination of active and passive control. Passive vibration reduction is mostly designed based on nonlinear elements such as wire rope structures, metal mesh, and air springs. While simple in configuration and highly reliable, its vibration reduction and attitude stabilization performance is less than satisfactory. Semi-active vibration reduction mostly uses dampers designed based on novel materials such as magnetorheological fluids. It controls the damping stiffness parameters by varying the current to cope with different operating conditions, effectively achieving vibration reduction and shock resistance, but its attitude stabilization performance is slightly insufficient. The active-passive combined system often uses elastic elements connected in parallel with electromagnetic or pneumatic actuators. Through appropriate control algorithms, it improves vibration reduction performance while simultaneously controlling the equipment's attitude.

[0003] However, existing active and passive composite vibration reduction and attitude stabilization technologies still have the following defects and shortcomings. For the problem of large-scale overload of dynamic load equipment, existing active actuators are difficult to meet the output requirements. If pneumatic actuators are used, the required air pressure is very high, and the requirement of equipping high-pressure air sources is difficult to meet on dynamic loads. At the same time, the increase in air pressure increases the system stiffness, thereby deteriorating the system's vibration reduction performance and making it difficult to meet the high-frequency vibration reduction requirements. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a variable load adaptive vibration isolator and vibration reduction and attitude stabilization platform with frequency-varying damping characteristics, so as to solve the problem that the existing active and passive composite vibration reduction and attitude stabilization technology cannot meet the high-frequency vibration reduction requirements.

[0005] To achieve the above objectives, according to one aspect of the present invention, a variable load adaptive vibration isolator with frequency-varying damping characteristics is provided, comprising a first cylinder, a second cylinder, a vibration isolation unit, and a sensing unit, wherein the first cylinder and the second cylinder are connected opposite to each other, and an inner cavity is formed between them; the vibration isolation unit includes a first piston and a second piston located within the inner cavity, the first piston and the second piston being coaxially arranged and connected at their ends, and further comprising:

[0006] A rubber diaphragm, with its middle part sandwiched between the first piston and the second piston, and its edge fixed between the connecting end faces of the first cylinder and the second cylinder, divides the inner cavity into a first chamber and a second chamber with variable space size and variable internal air pressure.

[0007] A guide bearing is fixed on the bottom surface of the first chamber away from the rubber membrane, and a first limiting member is provided on one end of the first piston that can abut against the guide bearing;

[0008] The first spring is sleeved on the first piston, and one end of it abuts against the first cylinder and is in a compressed state;

[0009] The pressure plate has the other end of the first piston extending out of the guide bearing and connected to the pressure plate. A deformable dynamic sealing membrane is also fixed between the pressure plate and the first piston. The middle part of the dynamic sealing membrane covers the opposite surfaces of the pressure plate and the first piston, and its edge is sealed and fixed to the first cylinder body.

[0010] The second spring is sleeved on the second piston, with one end abutting against the second cylinder and in a compressed state;

[0011] The frequency-varying damping structure includes a float, a frequency-varying damping spring, a damping sealing diaphragm, and an annular boss. The float is located on the end of the second piston away from the rubber diaphragm and is connected to the second piston via the frequency-varying damping spring. The annular boss is fixed to the second chamber and is positioned opposite to the guide bearing. A deformable damping sealing diaphragm is connected between the annular boss and the second piston to seal the float within the annular boss. A second limiting member that abuts against the float is also fixed on the inner bottom surface of the annular boss.

[0012] The sensing unit is mounted on the second cylinder and connected to the second piston. It is used to collect displacement signals when the vibration isolation unit moves along the axial direction.

[0013] Furthermore, the first spring and the second spring have the same stiffness value.

[0014] Furthermore, the preload of the first spring and the second spring are different.

[0015] Furthermore, the weight of the pontoon is less than 1 / 10 of the external load.

[0016] Furthermore, it also includes an adapter unit, which includes a first adapter flange for connecting an external load, and the first adapter flange is reversibly connected to the pressure plate.

[0017] Furthermore, the adapter unit also includes a second adapter flange that is rotatably connected to the second cylinder block, and the second adapter flange is connected to an external motorized platform.

[0018] Furthermore, the first piston is provided with a first boss, and the second piston is provided with a second boss that cooperates with the first boss, and the first boss and the second boss are detachably connected.

[0019] Furthermore, the other end of the first spring abuts against the first boss, and the other end of the second spring abuts against the second boss.

[0020] Furthermore, the sensing unit includes a displacement sensor and an electrical feedthrough element connected to each other. The displacement sensor is located in the second chamber, and the electrical feedthrough element is fixed on the second cylinder. The displacement sensor is connected to the second piston.

[0021] Furthermore, a first air hole for air inlet and outlet is provided on the side wall of the first chamber, and a second air hole for air inlet and outlet is provided on the side wall of the second chamber.

[0022] According to another aspect of the present invention, a degree-of-freedom vibration reduction and attitude stabilization platform is also disclosed, comprising a plurality of variable load adaptive vibration isolators with frequency-varying damping characteristics as described in any of the preceding claims, wherein the plurality of vibration isolators are respectively connected between an external load and an external motorized platform, and further comprising a controller connected to the vibration isolators, the controller being used to control each vibration isolator separately to achieve multi-degree-of-freedom variable load vibration reduction and attitude stabilization.

[0023] Compared with the prior art, the above technical solutions conceived by this invention have the following main advantages:

[0024] (1) The variable load adaptive vibration isolator designed in this invention has a dual chamber. The dual chambers are connected in parallel with air springs, which are coaxial and composed of dual springs and dual pistons to jointly bear the load. The relative working air pressure of the parallel air springs is reduced, so as to achieve low power displacement control, suppress resonance and prevent the high frequency vibration isolation effect from deteriorating. The variable load adaptive vibration isolator of this invention has a frequency-varying damping structure. The frequency-varying damping structure is integrated into the variable load vibration isolator, which further optimizes the vibration isolator structure and spatial layout. Specifically, the gap damping structure formed by the second piston, float and annular boss can achieve the effect of large damping at low frequency and small damping at high frequency. It effectively suppresses resonance and prevents the high frequency vibration isolation effect from deteriorating. It is suitable for variable load conditions with large overload.

[0025] (2) In this invention, the preload of the first spring and the second spring are different. By reasonably designing the preload of the two springs, the function of the air spring not bearing load under rated load conditions can be realized, reducing gas loss and improving the reliability of the vibration isolator, reducing power consumption and indirectly increasing the endurance of the air supply system.

[0026] (3) In this invention, the air pressure in the first chamber and the second chamber can be changed respectively. When an overload occurs, air can be injected into the corresponding chamber while the other chamber is controlled to release air, so that the air pressure in the venting chamber is the same as the atmospheric pressure, thereby reducing the relative working pressure of the high-pressure chamber, thus improving the safety of the vibration isolator and reducing the dependence on the high-pressure air source.

[0027] (4) The variable load adaptive vibration isolator with frequency-varying damping characteristics in this invention is also provided with a transfer unit at both ends. A multi-degree-of-freedom vibration reduction and attitude stabilization platform can be constructed by combining multiple vibration isolators. This multi-degree-of-freedom vibration reduction and attitude stabilization platform is not only suitable for large overload conditions, but also meets the vibration reduction and attitude stabilization requirements of various scenarios, which significantly improves the universality of the vibration isolator application of this invention. Attached Figure Description

[0028] Figure 1 This is a cross-sectional view of the overall structure of a variable load adaptive vibration isolator with frequency-varying damping characteristics provided in an embodiment of the present invention.

[0029] Figure 2 This is a partial schematic diagram of the frequency-variable damping structure of a variable load adaptive vibration isolator with frequency-variable damping characteristics provided in an embodiment of the present invention;

[0030] Figure 3 yes Figure 1 The diagram shows the vibration isolation principle of a variable load adaptive vibration isolator with frequency-varying damping characteristics.

[0031] Figure 4 This is the theoretical vibration transmissivity curve of the variable load adaptive vibration isolator with frequency-varying damping characteristics provided by the present invention under specific parameter configuration;

[0032] Figure 5 This is a flowchart of the operation of a variable load adaptive vibration isolator with frequency-varying damping characteristics provided in an embodiment of the present invention.

[0033] Figure 6 Another embodiment of the present invention provides a multi-degree-of-freedom variable load adaptive vibration reduction and attitude stabilization platform constructed from six variable load adaptive vibration isolators with frequency-varying damping characteristics;

[0034] Figure 7 This is another embodiment of the present invention, which provides a multi-degree-of-freedom variable load adaptive vibration reduction and attitude stabilization platform.

[0035] In the diagram: 1-First adapter flange, 2-First hinge joint, 3-Pressure plate, 4-Dynamic sealing membrane, 5-Guide bearing, 6-First cylinder body, 7-First chamber, 71-First spring, 72-First limiting component, 73-First piston, 74-First boss, 75-First vent, 8-Rubber membrane, 9-Second chamber, 91-Second spring, 92-Second limiting component, 93-Second piston, 94-Damping sealing membrane, 95-Frequency variable damping spring, 96-Float, 97-Annular boss, 98-Second boss, 99-Second vent, 10-Second cylinder body, 11-Displacement sensor, 12-Hollow support, 13-Electrical feedthrough element, 14-Second hinge joint, 15-Second adapter flange. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] To achieve the above objectives, combined with Figure 1 and Figure 2 As shown, this invention provides a variable load adaptive vibration isolator with frequency-varying damping characteristics. The isolator includes a first cylinder 6, a second cylinder 10, an isolation unit, and a sensing unit. The first cylinder 6 and the second cylinder 10 are connected at their respective cylinder ports, forming an inner cavity between them. The isolation unit includes a first piston 73, a first spring 71, a second piston 93, and a second spring 91, all located within the inner cavity and coaxially arranged. In this embodiment, both the first spring 71 and the second spring 91 are metal springs.

[0038] The ends of the first piston 73 and the second piston 93 are connected, and a deformable rubber membrane 8 is sandwiched between the connected ends; the edge of the rubber membrane 8 is fixed between the connecting end faces of the first cylinder 6 and the second cylinder 10, and divides the inner cavity into a first chamber 7 and a second chamber 9 with variable space size and variable internal air pressure.

[0039] A guide bearing 5 is fixed on the bottom surface of the first chamber 7 away from the rubber membrane 8. A first spring 71 is sleeved on the first piston 73, with one end abutting against the first cylinder 6 and in a compressed state. One end of the first piston 73 extends out of the guide bearing 5 and connects to the pressure plate 3. A first limiting member 72 is provided on the other end, which can abut against the guide bearing 5. A deformable dynamic sealing membrane 4 is provided between the pressure plate 3 and the first piston 73. The edge of the dynamic sealing membrane 4 is fixed to the first cylinder 6 to achieve a pneumatic seal on the first cylinder 6. The middle part of the dynamic sealing membrane 4 completely covers the inner surface of the pressure plate 3 facing the first piston 73, so that the pressure plate 3 can play the role of preventing the dynamic sealing membrane from deforming randomly. When the first piston 73 moves downward, it can drive the pressure plate 3 to move downward, thereby assembling and connecting the pressure plate 3 with the end of the guide bearing. The dynamic sealing membrane 4 covers the guide bearing 5, ensuring that the top of the first cylinder 6 achieves a pneumatic seal.

[0040] The second spring 91 is sleeved on the second piston 93, with one end abutting against the second cylinder 10 and in a compressed state. A float 96 is connected to the end of the second piston 93 away from the rubber diaphragm 8 via multiple parallel frequency-varying damping springs 95. Specifically, the float 96 and the second piston 93 cooperate to form an assembly space. Multiple frequency-varying damping springs are equally spaced and fixed in parallel between the inner bottom surface of the float 96 and the end face of the second piston 93. Simultaneously, a limiting flange (not shown in the figure) is provided on the side of the second piston 93 away from the float 96, which can cooperate and abut against the float 96. This limiting flange can restrict the stroke of the float moving axially towards the second piston 93. An annular boss 97 is fixed on the second chamber 9, opposite to the guide bearing 5. A deformable damping sealing diaphragm 94 connects the annular boss 97 and the second piston 93. The piston 93, when engaged, forms a sealed space inside the annular boss. The float 96 is located inside the annular boss 97. The second piston 93, the frequency-varying damping spring 95, the float 96, the damping sealing membrane, and the annular boss 97 work together to form a gap damping structure (i.e., a frequency-varying damping structure). The low-frequency damping force is transmitted to the second piston 93 with equal amplitude through the float 96 and the frequency-varying damping spring 95, while the high-frequency damping force is attenuated by the frequency-varying damping spring 95 and then transmitted to the second piston 93. This results in a large damping force in the low-frequency range and a small damping force in the high-frequency range, thereby achieving a frequency-varying damping effect and ensuring the high-frequency vibration reduction performance of the system after a large overload. The aforementioned float 96 is specifically a hollow cylindrical structure containing a bottom surface and a side surface surrounding the periphery of the bottom surface. A second limiting member 92 is fixed on the bottom surface inside the annular boss 97 to limit the movement of the float 96.

[0041] The sensing unit is mounted on the second cylinder 10 and connected to the second piston 93. It is used to collect displacement signals when the vibration isolation unit moves in the axial direction.

[0042] Specifically, in this embodiment, as follows: Figure 1 As shown, the first cylinder 6 and the second cylinder 10 are connected by bolts. When the vibration isolator is working, the first chamber 7 and the second chamber 9 are filled with air, forming a double-chamber parallel air spring with the first piston and the second piston 93. The axial movement of the first piston 73 and the second piston 93 can be controlled by filling and releasing gas in the first chamber 7 and the second chamber 9. For example, filling the first chamber 7 with air increases the internal pressure of the first chamber, causing the first piston 73 and the second piston 93 to move downward synchronously, or filling the second chamber 9 with air increases the internal pressure of the second chamber, causing the first piston 73 and the second piston 93 to move upward synchronously.

[0043] The aforementioned first piston 73 and second piston 93 are fixed together by bolts, with a thickened rubber membrane 8 sandwiched between them for sealing the first and second chambers, and the rubber membrane 8 is made of fluororubber mixed with adhesive cloth.

[0044] The upper end of the first spring 71 contacts the top of the first chamber 7, and the lower end of the first spring 71 abuts against the first piston 73 and is in a compressed state to achieve pre-compression. The upper end of the second spring 91 abuts against the second piston 93, and its lower end abuts against the bottom of the second chamber 9 to achieve a compressed state to achieve pre-compression.

[0045] More specifically, in this embodiment, the dimensions of the aforementioned dynamic sealing membrane 4, rubber membrane 8, and damping sealing membrane 94 are designed to be appropriately large, so that when the first piston 73 moves to its highest position, there is a certain gap between the dynamic sealing membrane 4 and the upper end face of the guide bearing. This ensures that the dynamic sealing membrane 4 can deform normally after assembly while still having a certain amount of space, preventing excessive tearing of the dynamic sealing membrane 4 caused by piston movement, thereby improving the reliability of the dynamic seal.

[0046] In this embodiment, the aforementioned first limiting member 72 and second limiting member 92 are made of elastic material with nonlinear stiffness. When the first piston 73 moves to the highest position, the distance between the first limiting member 72 and the lower end face of the guide bearing 5 is about 6mm. When the first piston 73 is in the equilibrium position and the vibration isolator encounters an impact, the first limiting member 72 and the lower end of the guide bearing 5 can abut against each other to achieve limiting, or the float 96 can abut against the second limiting member 92 to achieve the limiting effect on the second piston 93.

[0047] In this embodiment, the aforementioned parallel frequency-varying damping springs 95 are evenly distributed around the bottom surface of the second piston, and each frequency-varying damping spring 95 is welded and fixed to the corresponding second piston 93 and annular boss 97.

[0048] In this embodiment, the first spring 71 and the second spring 91, both made of metal, have the same stiffness value.

[0049] In this embodiment, the preload of the first spring 71 and the second spring 91 are different. Specifically, the preload of the first spring 71 and the second spring 91 can be reasonably designed according to actual needs to achieve the independent bearing of the first spring and / or the second spring under the rated working state, so as to reduce the pressure in the air chamber.

[0050] In this embodiment, the weight of the float 96 is less than 1 / 10 of the external load, that is, the weight of the float 96 is much less than the weight of the external load, which can ensure the reliability of the gap damping structure.

[0051] In this embodiment, the vibration isolator also includes a transfer unit, which includes a first transfer flange 1 for connecting an external load. The first transfer flange 1 and the pressure plate 3 are rotatably connected. Specifically, a first hinge joint 2 is provided between the first transfer flange 1 and the pressure plate 3. The first hinge joint 2 passes through the pressure plate 3 and the dynamic sealing membrane 4 in sequence and is connected to the first piston by a threaded connection. The dynamic sealing membrane 4 is fixed to the upper end of the first piston 73 together with the pressure plate 3 by a nut. The edge of the dynamic sealing membrane 4 is fixedly connected to the first cylinder 6 by bolts to seal the first cylinder 6.

[0052] In this embodiment, the adapter unit also includes a second adapter flange 15 that is rotatably connected to the second cylinder 10. The second adapter flange 15 is connected to an external motorized platform. Specifically, a second hinge joint 14 is provided between the second adapter flange 15 and the second cylinder 10. The second hinge joint 14 is connected to the second cylinder 10 by a threaded connection.

[0053] In this embodiment, the first piston 73 is provided with a first boss 74, and the second piston 93 is provided with a second boss 98 that cooperates with the first boss. The first boss 74 and the second boss 98 are detachably connected so that the first piston 73 and the second piston 93 can also be detachably connected. Specifically, the first boss 74 and the second boss 98 have the same outer diameter, and both are provided with matching mounting holes. Screws are inserted in the mounting holes to connect and fix the first piston 73 and the second piston 93.

[0054] More specifically, in this embodiment, the other end of the first spring 71 abuts against the first boss 74 and is located outside the first limiting member 72, and the other end of the second spring 91 abuts against the second boss 98 and is located outside the damping sealing film 94.

[0055] In this embodiment, the sensing unit includes a displacement sensor 11 and an electrical feedthrough element 13 connected to each other. The displacement sensor 11 is located in the second chamber 9, the electrical feedthrough element 13 is fixed on the second cylinder 10, and the displacement sensor 11 is connected to the second piston 93.

[0056] Specifically, a hollow support 12 is also provided in the second cylinder body. The hollow support 12 is a hollow tube through which a cable for connecting the displacement sensor 11 and the electrical feedthrough element 13 is passed. More specifically, the mover of the displacement sensor 11 is fixedly connected to the second piston 93, and its stator is interference-fitted with the hollow support 12. The hollow support 12 is interference-fitted with the assembly space in the second cylinder body 10.

[0057] In this embodiment, a first air hole 75 for air inlet and outlet is provided on the side wall of the first chamber 7, and a second air hole 99 for air inlet and outlet is provided on the side wall of the second chamber 9. The first air hole 75 and the second air hole 99 can be used to jointly control the amount of air in the corresponding chamber through the corresponding reversing valve and proportional valve, and combined with the displacement sensor 11, to achieve bidirectional displacement control.

[0058] like Figure 3 The diagram shown illustrates the working principle of a vibration isolator provided in any of the aforementioned embodiments. The base is connected to the lower end of the vibration isolator, and the vibration displacement is expressed as... z b The equipment is connected to the upper end of the vibration isolator, and the vibration displacement is expressed as... z The performance of the vibration isolator is mainly determined by the frequency-varying damping unit and the vibration isolation unit. High-performance vibration isolation is achieved by connecting the two in parallel. The system transmissivity is as follows:

[0059] (1)

[0060] in, T Indicates vibration transmissibility. z This indicates the amplitude of the load vibration displacement. zb This indicates the amplitude of the base vibration displacement. m Indicates negative mass. mc Indicates the mass of the pontoon. s This represents the complex variable generated by the Laplace transform of a time-domain signal. k 's' represents the stiffness of a single metal spring. k 'a' represents the air spring stiffness. k c represents the stiffness of the frequency-varying damping spring, and c represents the damping coefficient.

[0061] like Figure 4 The figure shows the theoretical vibration transmissivity curve of a vibration isolator with frequency-varying damping characteristics provided in an embodiment of the present invention. The stiffness values ​​and preload of the first and second springs are reasonably configured. It can be seen that this vibration isolator with frequency-varying damping characteristics can suppress resonance while sacrificing a small portion of the mid-frequency band vibration reduction effect, thereby significantly improving the high-frequency band vibration reduction performance. For large variable load conditions, it can effectively solve the problem of high-frequency vibration isolation effect deterioration caused by the increase of air cavity stiffness.

[0062] Through the above design, when the adaptive vibration isolator with frequency-varying damping characteristics provided in any embodiment of the present invention is operating in its rated state, the entire unit is in a passive vibration reduction mode, relying solely on two pre-tightened metal springs (i.e., the first spring and the second spring) for load bearing. When an overload occurs, the relative displacement exceeds the allowable range. By controlling the reversing valve and the proportional valve, air is injected into the corresponding first or second chamber until the vibration isolation unit returns to the predetermined equilibrium position. The chamber pressure is maintained until the overload ends, and then the corresponding chamber is depressurized, achieving low-power vibration reduction and posture stabilization. The specific adjustment method is as follows: Figure 5 As shown, it includes the following steps:

[0063] S1 isolator is in passive vibration reduction mode. Determine if the load changes significantly: if not, repeat the determination of whether the isolator is in passive vibration reduction mode; if so, proceed to the next step.

[0064] S2 controls the reversing valve and proportional valve to replenish air into the corresponding chambers. When replenishing air, it checks whether the relative displacement of the vibration isolation unit in the vibration isolator meets the standard: if not, it continues to replenish air; if so, it proceeds to the next step.

[0065] S3 controls the directional valve and proportional valve to maintain the current pressure in the corresponding chamber and determines whether the relative displacement of the vibration isolation unit in the vibration isolator meets the standard: if yes, the current pressure is maintained; if no, the next step is executed.

[0066] S4 terminates the overload and controls the corresponding chamber to release air to reduce pressure, entering passive vibration reduction mode.

[0067] This invention utilizes a frequency-varying damping structure to ensure the high-frequency vibration reduction performance of the system after significant overload. Furthermore, in this invention, when the vibration isolator is subjected to a violent external impact at its equilibrium position, the first and second limiting members can restrict the movement of the vibration isolation unit, preventing damage to the corresponding piston.

[0068] It should be noted that the adaptive vibration isolator with frequency-varying damping characteristics according to the present invention is not limited to single use, but can be used in combination with corresponding control methods to meet the requirements of multi-degree-of-freedom vibration reduction and attitude stabilization.

[0069] Example 2

[0070] As shown in Figure 6, this embodiment provides a multi-dimensional vibration reduction and attitude stabilization platform constructed from six adaptive vibration isolators with frequency-varying damping characteristics as provided in Embodiment 1 above. It is a Stewart configuration, with the six vibration isolators set between two upper and lower platforms. Real-time triaxial angular acceleration and acceleration information are obtained through inertial sensors set on the upper and lower platforms. An external controller is also connected. The controller calculates the relative attitude of the vibration isolators in real time through the corresponding algorithm. The position information of the connection points of each vibration isolator unit is solved through the Jacobian matrix of the platform kinematic model. The multi-degree-of-freedom control is decoupled into single-degree-of-freedom control of each vibration isolator unit. The high-performance low-frequency attitude stabilization and mid-to-high-frequency vibration isolation effect are achieved through relative displacement feedback, which meets the requirements of multi-degree-of-freedom vibration reduction and attitude stabilization under large overload conditions.

[0071] Example 3

[0072] like Figure 7 As shown, this embodiment provides a multi-dimensional vibration reduction and attitude stabilization platform constructed from six adaptive vibration isolators with frequency-varying damping characteristics. It features a decoupled distributed configuration, with the central axes of two adjacent adaptive vibration isolators with frequency-varying damping characteristics positioned between the upper and lower platforms perpendicular to each other. This type of multi-dimensional vibration reduction and attitude stabilization platform can achieve the same function as in Embodiment 2, namely, decoupling multi-degree-of-freedom control into single-degree-of-freedom control of each vibration isolator unit. Through relative displacement feedback, it achieves high-performance low-frequency attitude stabilization and mid-to-high-frequency vibration isolation, meeting the requirements for multi-degree-of-freedom vibration reduction and attitude stabilization under significant overload conditions.

[0073] In summary, the variable load adaptive vibration isolator according to the present invention solves the problem of deterioration of high-frequency vibration reduction effect after large overload by integrating a frequency-varying damping structure, effectively suppressing resonance while ensuring high-frequency vibration isolation performance. At the same time, by designing the preload of the first and second springs, the air springs are not loaded under rated load conditions, reducing system power consumption. When an overload occurs, the high-pressure chamber is inflated while the other chamber is kept connected to the atmosphere, thereby reducing the relative working air pressure of the high-pressure chamber and improving the safety and reliability of the vibration isolator. Through reasonable combination and distribution, a multi-degree-of-freedom vibration reduction and attitude stabilization platform is formed. Combined with the corresponding feedback control method, it can achieve high-performance low-frequency attitude stabilization and mid-to-high-frequency vibration isolation functions with six degrees of freedom, and has broad application prospects in the field of large variable load vibration reduction and attitude stabilization.

[0074] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0075] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 this invention according to the specific circumstances.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable load adaptive isolator having a frequency dependent damping characteristic, characterized by, The system includes a first cylinder (6), a second cylinder (10), a vibration isolation unit, and a sensing unit. The cylinder ports of the first cylinder (6) and the second cylinder (10) are connected to each other, and an inner cavity is formed between them. The vibration isolation unit includes a first piston (73) and a second piston (93) located in the inner cavity. The first piston (73) and the second piston (93) are coaxially arranged and connected at their ends. The system also includes: A rubber diaphragm (8) is fixed in the middle between the connecting ends of the first piston (73) and the second piston (93), and its edge is fixed between the connecting end faces of the first cylinder (6) and the second cylinder (10), and divides the inner cavity into a first chamber (7) and a second chamber (9) with variable space size and variable internal air pressure. A guide bearing is fixed on the bottom surface of the first chamber (7) away from the rubber membrane (8), and a first limiting member (72) is provided on one end of the first piston (73) that can abut against and connect with the guide bearing (5). The first spring (71) is sleeved on the first piston (73), and one end of it abuts against the first cylinder (6) and is in a compressed state; The pressure plate (3) is located outside the inner cavity. The other end of the first piston (73) passes through the guide bearing (5) and is connected to the pressure plate (3). A deformable dynamic sealing membrane (4) is also fixed between the pressure plate (3) and the first piston (73). The middle part of the dynamic sealing membrane (4) covers the opposite surfaces of the pressure plate (3) and the first piston (73), and its edge is sealed and fixed on the first cylinder (6). The second spring (91) is sleeved on the second piston (93), with one end abutting against the second cylinder (10) and in a compressed state; The frequency-varying damping structure includes a float (96), a frequency-varying damping spring (95), a damping sealing membrane (94), and an annular boss (97). The float (96) is located on the end of the second piston (93) away from the rubber membrane (8) and is connected to the second piston (93) through the frequency-varying damping spring (95). The annular boss (97) is fixed on the second chamber (9) and is arranged opposite to the guide bearing (5). A deformable damping sealing membrane (94) is connected between the annular boss (97) and the second piston (93) to seal the float (96) inside the annular boss (97). A second limiting member (92) that can abut against the float (96) is also fixed on the bottom surface of the annular boss (97). The sensing unit is mounted on the second cylinder (10) and connected to the second piston (93), and is used to collect displacement signals when the vibration isolation unit moves along the axial direction.

2. A variable load self-adaptive vibration isolator with frequency- varying damping characteristics as claimed in claim 1, wherein, The first spring (71) and the second spring (91) have the same stiffness value.

3. A variable load self-adaptive vibration isolator with frequency- varying damping characteristics as claimed in claim 1, wherein, The preload of the first spring (71) and the second spring (91) are different.

4. A variable load self-aligning vibration isolator with frequency dependent damping characteristics as claimed in claim 1 wherein, The weight of the pontoon (96) is less than 1 / 10 of the external load.

5. A variable load self-aligning vibration isolator with frequency dependent damping characteristics as claimed in claim 1 wherein, It also includes a transfer unit, which includes a first transfer flange (1) for connecting an external load, and the first transfer flange (1) is reversibly connected to the pressure plate (3).

6. A variable load self-aligning vibration isolator with frequency dependent damping characteristics as claimed in claim 5 wherein, The adapter unit also includes a second adapter flange (15) that is rotatably connected to the second cylinder (10), and the second adapter flange (15) is connected to an external motorized platform.

7. A variable load adaptive vibration isolator with frequency-varying damping characteristics as described in claim 1, characterized in that, The first piston (73) is provided with a first boss (74), and the second piston is provided with a second boss (98) that cooperates with the first boss. The first boss (74) and the second boss (98) are detachably connected.

8. A variable load adaptive vibration isolator with frequency-varying damping characteristics as described in claim 7, characterized in that, The other end of the first spring (71) abuts against the first boss (74), and the other end of the second spring (91) abuts against the second boss (98).

9. A variable load adaptive vibration isolator with frequency-varying damping characteristics as described in claim 1, characterized in that, The sensing unit includes a displacement sensor (11) and an electrical feedthrough element (13) connected to each other. The displacement sensor (11) is located in the second chamber (9), and the electrical feedthrough element (13) is fixed on the second cylinder (10). The displacement sensor (11) is connected to the second piston (93).

10. A variable load adaptive vibration isolator with frequency-varying damping characteristics as described in claim 1, characterized in that, The first chamber (7) has a first air hole (75) for air inlet and outlet on its side wall, and the second chamber (9) has a second air hole (99) for air inlet and outlet on its side wall.

11. A degree-of-freedom vibration reduction and attitude stabilization platform, characterized in that, It includes multiple variable load adaptive vibration isolators with frequency-varying damping characteristics as described in any one of claims 1-10, wherein the multiple vibration isolators are respectively connected between an external load and an external mobile platform; it also includes a controller connected to the vibration isolators, wherein the controller is used to control each vibration isolator to achieve multi-degree-of-freedom variable load vibration reduction and attitude stabilization.

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