Intelligent Vibration Isolator and Its Damping and Stiffness Adjustment Method

Abstract

The present invention discloses an intelligent vibration isolator and its damping and stiffness adjustment method. The intelligent vibration isolator includes a top plate, a bottom plate, a damping adjustment mechanism, a plurality of stiffness adjustment mechanisms, an acceleration sensor, a signal processor, and a central processor. One end of the damping adjustment mechanism is connected to the top plate, and the other end is connected to the bottom plate. The plurality of stiffness adjustment mechanisms are located between the top plate and the bottom plate. The acceleration sensor detects the vibration information during external excitation in real time. The signal processor performs frequency-domain analysis and vibration level evaluation on the vibration information. When adjustment is required, the central processor adjusts the damping adjustment mechanism and the stiffness adjustment mechanism according to the pre-stored optimal damping adjustment position, optimal stiffness adjustment position, frequency-domain analysis result, and vibration level evaluation result. The present invention can achieve simultaneous and autonomous adjustment of damping and stiffness, change the effective vibration isolation frequency of the vibration isolator, and broaden the vibration isolation frequency band.

Description

Technical Field

[0001] The present invention belongs to the technical field of vibration control, and particularly relates to an intelligent vibration isolator and a method for adjusting its damping and stiffness. Background Art

[0002] Currently, more and more cities have subways, and the number of subway lines in each developed city is also increasing. The vibration generated by each subway line during operation will inevitably affect the buildings on the ground. Therefore, the demand for vibration isolation of buildings is also increasing.

[0003] Traditional vibration isolation devices are rubber-based and metal spring-based, and achieve vibration isolation by separating the vibration source and the object to be vibration-isolated. The function of vibration isolation is to reduce the dynamic coupling between the vibration source and the object to be vibration-isolated, thereby reducing the transmission of adverse vibrations to the object to be vibration-isolated. Metal spring vibration isolators have the characteristics of good load-bearing capacity, strong stability, being unaffected by temperature changes, and not aging or creeping, etc., and can well reduce the transmission of vibrations during the vibration isolation process.

[0004] The vibration isolator can flexibly connect the building and the foundation, reduce the transmission of vibration energy from the foundation to the building, and achieve the effect of isolating vibrations. However, the actual vibration isolation effect is related to the vibration frequency transmitted from the foundation. In most cases, the vibrations generated by subway trains may have various changes, such as continuous departures, changes in vehicle speed, changes in carriage weight, etc., resulting in the uncertainty of the vibration source. The vibration frequency generated by the subway during operation is usually a process that changes with time. The vibration isolation effect of a vibration isolator with fixed parameters is only good in some frequency bands and is difficult to cover all the frequencies generated during subway operation. Therefore, when using a vibration isolator with fixed parameters, it is impossible to ensure the vibration isolation effect in the full frequency band.

[0005] Currently, vibration isolators that can adjust stiffness and damping cannot achieve real-time adjustment functions, and it is difficult to isolate vibrations of different frequencies generated by the subway over time. Summary of the Invention

[0006] The purpose of the present invention is to provide an intelligent vibration isolator and a method for adjusting its damping and stiffness, so as to solve the problem that traditional vibration isolators cannot adjust the damping and stiffness characteristics in real time with the change of the excitation frequency, and thus cannot ensure the vibration isolation effect in the full frequency band.

[0007] The present invention solves the above technical problems through the following technical solutions: An intelligent vibration isolator is provided between the object to be vibration-isolated and its foundation. The intelligent vibration isolator includes:

[0008] A top plate and a bottom plate;

[0009] A damping adjustment mechanism, one end of which is connected to the center of the lower end face of the top plate, and the other end is connected to the center of the upper end face of the bottom plate. The damping adjustment mechanism adjusts the damping in real time under the damping adjustment instruction of the central processor;

[0010] At least four stiffness adjustment mechanisms, and a plurality of the stiffness adjustment mechanisms are located between the top plate and the bottom plate and are evenly distributed around the damping adjustment mechanism. Each stiffness adjustment mechanism adjusts the stiffness in real time under the stiffness adjustment instruction of the central processing unit;

[0011] An acceleration sensor for collecting vibration information of the vibration isolation object when it is subjected to external excitation;

[0012] A signal processor for performing frequency-domain power spectrum analysis on the vibration information collected by the acceleration sensor to obtain the main frequency information of the external excitation, and performing 1 / 3 octave vibration level evaluation on the frequency range where the main frequency information is located to obtain a 1 / 3 octave vibration level evaluation result;

[0013] A central processing unit for storing the optimal damping adjustment position of the damping adjustment mechanism at different 1 / 3 octave center frequencies and the optimal stiffness adjustment position of each stiffness adjustment mechanism at different 1 / 3 octave center frequencies; judging whether damping and stiffness adjustment are required according to the 1 / 3 octave vibration level evaluation result; when damping and stiffness adjustment are required, generating a damping adjustment instruction according to the optimal damping adjustment position at different 1 / 3 octave center frequencies and the main frequency information sent by the signal processor, and generating a stiffness adjustment instruction according to the optimal stiffness adjustment position at different 1 / 3 octave center frequencies and the main frequency information sent by the signal processor.

[0014] Further, the damping adjustment mechanism includes an upper support cylinder, a damping cylinder, damping liquid, a damping block, a rotating screw, a rotating gear and a first motor; an upper support cylinder is provided on the damping cylinder, the damping cylinder is filled with damping liquid, the damping block is arranged in the damping cylinder and one end thereof is connected to the rotating gear through the rotating screw; the rotating gear is meshed with the output gear of the first motor, and the first motor and the rotating gear are arranged in the upper support cylinder; the top end of the upper support cylinder is fixedly connected to the center of the lower end surface of the top plate, and the bottom end of the damping cylinder is connected to the center of the upper end surface of the bottom plate;

[0015] The first motor drives the damping block to move up and down through the rotating gear and the rotating screw under the control of the damping adjustment instruction, adjusts the contact area between the damping block and the damping liquid to change the damping value, and further reaches the optimal damping adjustment position.

[0016] Further, the outer diameter of the upper support cylinder is adapted to the inner diameter of the damping cylinder, so that the lower part of the upper support cylinder is embedded in the damping cylinder and can slide relatively.

[0017] Further, the damping block is cylindrical and has spiral grooves on its outer surface.

[0018] Further, each of the stiffness adjustment mechanisms includes a cushion block, a limiting cylinder, a spring, a fixing screw, a spring control device, an idle spring cylinder, a toothed nut, a connecting rod, and a second motor; the limiting cylinder is fixedly arranged at the bottom of the cushion block, and the bottom of the limiting cylinder is fixedly connected to one end of the fixing screw, and the other end of the fixing screw is fixedly connected to the connecting rod; the fixing screw sequentially penetrates through the spring control device, the idle spring cylinder, and the toothed nut from top to bottom and is threadedly connected to the toothed nut; the spring control device is fixedly connected to the idle spring cylinder, and the idle spring cylinder is fixedly connected to the toothed nut;

[0019] A through hole for the spring to pass through is provided on the spring control device during the up and down movement of the spring control device. The idle spring cylinder is of a hollow structure, and the hollow structure is used to store the part of the spring that does not play a supporting role; the upper end of the spring is sleeved outside the limiting cylinder, and its lower end is sleeved outside the fixing screw, passes through the through hole, and extends into the hollow structure of the idle spring cylinder; the cushion block is fixedly connected to the top plate, and the connecting rod is fixedly connected to the bottom plate;

[0020] The output gear of the second motor meshes with the toothed nut. The second motor drives the spring control device and the idle spring cylinder to move on the fixing screw through the toothed nut under the control of the stiffness adjustment instruction, adjusts the actual working turns of the spring to change the stiffness value, and further reaches the optimal stiffness adjustment position.

[0021] Preferably, the limiting cylinder, the spring control device, the idle spring cylinder, the fixing screw, and the connecting rod are all coaxially arranged.

[0022] Preferably, the cushion block is a rubber pad, the rubber pad is compressible, and a metal gasket is provided at the bottom.

[0023] Further, the acceleration sensor, the signal processor, and the central processor are all arranged on the bottom plate.

[0024] Preferably, the sampling time interval of the acceleration sensor is the time interval when adjacent vibration sources pass through the bottom of the vibration isolation object.

[0025] Further, the intelligent vibration isolator further includes a battery module, and the battery module is used to provide power to the intelligent vibration isolator when the external power supply is interrupted.

[0026] Preferably, the intelligent vibration isolator further includes a remote monitoring center communicatively connected to the signal processor.

[0027] Based on the same inventive concept, the present invention also provides a method for adjusting the damping and stiffness of the above-mentioned intelligent vibration isolator, including the following steps:

[0028] Obtain the vibration information of the vibration-isolated object when it is subjected to external excitation;

[0029] Perform frequency-domain power spectrum analysis on the vibration information to obtain the main frequency information of the external excitation, and perform 1 / 3 octave vibration level evaluation on the vibration information to obtain the 1 / 3 octave vibration level evaluation result;

[0030] Judge whether damping and stiffness adjustment are required according to the vibration level evaluation result at the 1 / 3 octave center frequency corresponding to the main frequency information of the external excitation;

[0031] When damping and stiffness adjustment are required, generate a damping adjustment command according to the main frequency information of the external excitation and the optimal damping adjustment positions at different 1 / 3 octave center frequencies stored in advance, and generate a stiffness adjustment command according to the main frequency information of the external excitation and the optimal stiffness adjustment positions at different 1 / 3 octave center frequencies stored in advance;

[0032] Under the control of the damping adjustment command, drive the first motor of the damping adjustment mechanism to work and adjust the damping in real time;

[0033] Under the control of the stiffness adjustment command, drive the second motor of each stiffness adjustment mechanism to work and adjust the stiffness in real time.

[0034] Further, the specific determination process of the optimal damping adjustment position and the optimal stiffness adjustment position at different 1 / 3 octave center frequencies is as follows:

[0035] Obtain the vibration information of the vibration-isolated object when it is subjected to different external excitations;

[0036] Perform frequency-domain power spectrum analysis on the vibration information under different external excitations to obtain the main frequency information of each external excitation;

[0037] Determine the frequency range where the main frequency information is located and the 1 / 3 octave center frequency within this frequency range according to the main frequency information of each external excitation;

[0038] Use vibration isolation theory and experimental method to determine the optimal damping adjustment position and the optimal stiffness adjustment position at each 1 / 3 octave center frequency.

[0039] Further, the specific implementation process of using vibration isolation theory and experimental method to determine the optimal damping adjustment position and the optimal stiffness adjustment position at each 1 / 3 octave center frequency is as follows:

[0040] At each 1 / 3 octave center frequency, adjust the damping ratio by adjusting the damping adjustment mechanism When the damping ratio ζ is between 0.04 and 0.06, the optimal position of the damping block in the damping liquid in the damping adjustment mechanism is determined in combination with the vibration isolation effect, and this optimal position is the optimal damping adjustment position; where C is the damping of the system composed of the intelligent vibration isolator and the object to be vibration isolated, and C c is the critical damping;

[0041] At each 1 / 3 octave center frequency, the frequency ratio is adjusted by adjusting the stiffness adjustment mechanism When the frequency ratio

[0042] is reached, the optimal position of the toothed nut on the fixed screw in the stiffness adjustment mechanism is determined in combination with the vibration isolation effect, and this optimal position is the optimal stiffness adjustment position; where ω is the frequency of the external excitation, and ω n is the natural frequency of the system composed of the intelligent vibration isolator and the object to be vibration isolated.

[0043] Advantages

[0044] Compared with the prior art, the advantages of the present invention are as follows:

[0045] An intelligent vibration isolator and its damping and stiffness adjustment method provided by the present invention perform real-time monitoring and analysis on the vibration information during external excitation, and judge whether the damping and stiffness adjustment conditions are met according to the 1 / 3 octave vibration level evaluation result. When the adjustment conditions are met, the real-time adjustment of the damping characteristics and stiffness characteristics is realized by adjusting the damping adjustment mechanism and the stiffness adjustment mechanism, changing the effective vibration isolation frequency of the vibration isolator, and broadening the vibration isolation frequency band;

[0046] Since the present invention generates a damping adjustment instruction (that is, determines the damping adjustment degree) according to the optimal damping adjustment position at different 1 / 3 octave center frequencies stored in advance, and generates a stiffness adjustment instruction (that is, determines the stiffness adjustment degree) according to the optimal stiffness adjustment position at different 1 / 3 octave center frequencies stored in advance, the present invention can achieve the optimal adjustment of damping and stiffness by issuing an adjustment instruction once, and combining dynamic vibration isolation with damping energy dissipation vibration isolation can quickly achieve the optimal vibration isolation and energy absorption effect;

[0047] The present invention can realize the simultaneous and autonomous adjustment of damping and stiffness without external interference, can meet the vibration isolation effect under various working conditions, and is of great significance for improving the adjustment flexibility of the vibration isolator and broadening the vibration isolation frequency band. Description of the Drawings

[0048] To more clearly illustrate the technical solution of the present invention, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the drawings described below are only one embodiment of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0049] Figure 1 is a schematic structural diagram of the intelligent vibration isolator in the embodiment of the present invention;

[0050] Figure 2 is a schematic structural diagram of the damping adjustment mechanism in the embodiment of the present invention;

[0051] Figure 3 is a schematic structural diagram of the stiffness adjustment structure in the embodiment of the present invention;

[0052] Figure 4 is a flow chart of the damping and stiffness adjustment method in the embodiment of the present invention;

[0053] Figure 5 is a frequency domain power spectrum diagram in the embodiment of the present invention;

[0054] Figure 6 is an amplitude-frequency characteristic curve diagram of the absolute motion transmissibility in the embodiment of the present invention.

[0055] Figure 7 is a 1 / 3 octave band vibration level evaluation result diagram in the embodiment of the present invention;

[0056] Among them, 1 - top plate; 2 - bottom plate; 3 - damping adjustment mechanism; 4 - stiffness adjustment mechanism; 5 - acceleration sensor; 6 - signal processor; 7 - central processor; 8 - battery module; 9 - remote monitoring center; 301 - upper support cylinder; 302 - damping cylinder; 303 - damping liquid; 304 - damping block; 305 - rotating screw; 306 - rotating gear; 307 - first motor; 401 - rubber pad; 402 - limiting cylinder; 403 - spring; 404 - fixing screw; 405 - spring control device; 406 - idle spring cylinder; 407 - toothed nut; 408 - connecting rod; 409 - second motor. Specific Embodiments

[0057] The following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0058] The technical solution of the present application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0059] When the same subway train passes by, the amplitude and main frequency information of the excitation acceleration generated may be relatively uniform or change little. However, in different situations, for example, there are significant differences and changes in the number of passengers on weekdays and weekends, which leads to a change in the vehicle body mass, thereby causing a change in the excitation frequency generated by the vehicle body. At this time, it is necessary to adjust the damping and stiffness of the vibration isolator to ensure the vibration isolation effect. Based on this, the present invention proposes an intelligent vibration isolator that can autonomously and dynamically adjust the damping and stiffness, and effectively isolates different frequency vibrations generated by the subway over time, broadening the vibration isolation frequency band.

[0060] An intelligent vibration isolator provided in an embodiment of the present invention can autonomously adjust the damping and stiffness characteristics. The intelligent vibration isolator is vertically supported between a building foundation (such as the ground) and a building (i.e., the object to be vibration isolated) to reduce the transfer of vibration energy from the building foundation to the building. As Figure 1 shown in the intelligent vibration isolator, it includes a top plate 1, a bottom plate 2, a damping adjustment mechanism 3, four stiffness adjustment mechanisms 4, an acceleration sensor 5, a signal processor 6, and a central processor 7; one end of the damping adjustment mechanism 3 is connected to the center of the lower end surface of the top plate 1, and the other end is connected to the center of the upper end surface of the bottom plate 2; the four stiffness adjustment mechanisms 4 are located between the top plate 1 and the bottom plate 2 and are evenly distributed around the damping adjustment mechanism 3; the acceleration sensor 5, the signal processor 6, and the central processor 7 are all provided on the bottom plate 2, the acceleration sensor 5 is connected to the signal processor 6, the signal processor 6 is connected to the central processor 7, and the central processor 7 is also connected to a first motor 307 in the damping adjustment mechanism 3 and a second motor 409 in the stiffness adjustment mechanism 4.

[0061] The acceleration sensor 5 collects vibration information or acceleration information of the vibration isolation object (such as a building) when it is subjected to external disturbances (excitation disturbances); the signal processor 6 performs frequency-domain power spectrum analysis on the vibration information collected by the acceleration sensor 5 to obtain the main frequency information of the external disturbance, determines the frequency range where the main frequency information is located, and performs 1 / 3 octave band vibration level evaluation on the vibration information to obtain the 1 / 3 octave band vibration level evaluation result; in the database of the central processor 7, the optimal damping adjustment position of the damping adjustment mechanism 3 and the optimal stiffness adjustment position of each stiffness adjustment mechanism 4 at different 1 / 3 octave band center frequencies are pre-stored; the central processor 7 judges whether damping and stiffness adjustment are required according to the 1 / 3 octave band vibration level evaluation result at the 1 / 3 octave band center frequency corresponding to the main frequency information of the external disturbance. When damping and stiffness adjustment are required, a damping adjustment instruction is generated according to the optimal damping adjustment position at different 1 / 3 octave band center frequencies and the main frequency information sent by the signal processor 6, and a stiffness adjustment instruction is generated according to the optimal stiffness adjustment position at different 1 / 3 octave band center frequencies and the main frequency information sent by the signal processor 6.

[0062] In the database of the central processor 7, each 1 / 3 octave band center frequency corresponds to an optimal damping adjustment position and an optimal stiffness adjustment position, and any main frequency information obtained by frequency-domain power spectrum analysis corresponds to a 1 / 3 octave band center frequency (determined by the 1 / 3 octave band center frequency range where the main frequency is located). Each time the acceleration sensor 5 collects vibration information (corresponding to the vibration information within a collection period), when damping and stiffness adjustment are required, the central processor 7 can determine the optimal damping adjustment position and the optimal stiffness adjustment position according to the pre-stored optimal damping adjustment positions at different 1 / 3 octave band center frequencies, the optimal stiffness adjustment positions at different 1 / 3 octave band center frequencies, and the main frequency information of the current external disturbance. By adjusting the damping adjustment mechanism 3 to the optimal damping adjustment position (i.e., the real-time adjustment process of the damping magnitude) and each stiffness adjustment mechanism 4 to the optimal stiffness adjustment position (i.e., the real-time adjustment process of the stiffness magnitude), the optimal vibration isolation effect is achieved.

[0063] The present invention only performs damping and stiffness adjustment when the damping and stiffness adjustment conditions are met (judging whether the conditions are met according to the 1 / 3 octave band vibration level evaluation result), making the necessity of adjustment clearer, and does not require adjustment every time the acceleration sensor 5 collects data or when the external disturbance changes little, thus improving the service life of the vibration isolator. Since the motors of the damping adjustment mechanism 3 and the stiffness adjustment mechanism 4 are not shared, the damping and stiffness of the present invention can be adjusted synchronously and independently, improving the adjustment efficiency.

[0064] In this embodiment, the sampling time interval of the acceleration sensor 5 is the time interval when adjacent subway trains (vibration sources) pass under the building (vibration isolation object), that is, every time a subway passes under the building, the acceleration sensor 5 performs a data sampling.

[0065] In a specific embodiment of the present invention, as Figure 2 shown, the damping adjustment mechanism 3 includes an upper support cylinder 301, a damping cylinder 302, damping liquid 303, a damping block 304, a rotating screw 305, a rotating gear 306, and a first motor 307; an upper support cylinder 301 is provided on the damping cylinder 302, and the damping cylinder 302 is filled with damping liquid 303 (when the damping block 304 is located at the bottom of the damping cylinder 302, the damping liquid 303 submerges the damping block 304), the damping block 304 is arranged in the damping cylinder 302 and one end thereof is connected to the rotating gear 306 through a rotating screw 305 passing through the center of the bottom of the upper support cylinder 301; the rotating gear 306 meshes with the output gear of the first motor 307, and the first motor 307 and the rotating gear 306 are arranged at the bottom of the upper support cylinder 301; the top end of the upper support cylinder 301 is fixedly connected to the center of the lower end surface of the top plate 1, and the bottom end of the damping cylinder 302 is connected to the center of the upper end surface of the bottom plate 2.

[0066] When damping adjustment is required, the first motor 307 drives the rotating gear 306 to rotate under the control of a damping adjustment instruction, drives the damping block 304 to move up and down through the rotating gear 306 and the rotating screw 305, so as to adjust the contact area between the damping block 304 and the damping liquid 303 (or the position of the damping block 304 in the damping liquid 303) to change the damping magnitude. When the optimal damping adjustment position (or optimal damping value) is reached, the current damping adjustment is stopped.

[0067] In this embodiment, the outer diameter of the upper support cylinder 301 is adapted to the inner diameter of the damping cylinder 302, so that the lower part of the upper support cylinder 301 is embedded in the damping cylinder 302 and can slide relatively, realizing the buffering function of the damping adjustment mechanism 3. The damping block 304 is cylindrical and has spiral grooves on its outer surface, increasing the contact area between the damping block 304 and the damping liquid 303. The rotating screw 305 passes through the center of the bottom of the upper support cylinder 301 and is threadedly connected to the center of the bottom of the upper support cylinder 301.

[0068] In a specific embodiment of the present invention, four stiffness adjustment mechanisms 4 are located at the four corners of the top plate 1 and the bottom plate 2. Combining with the damping adjustment mechanism 3 in the center, the load-bearing stability of the vibration isolator is improved. As Figure 3As shown in the figure, each stiffness adjustment mechanism 4 includes a cushion block, a limiting cylinder 402, a spring 403, a fixing screw, a spring control device 405, an idle spring cylinder 406, a toothed nut 407, a connecting rod 408, and a second motor 409; the limiting cylinder 402 is fixedly arranged at the bottom of the cushion block, and the bottom of the limiting cylinder 402 is fixedly connected to one end of the fixing screw, and the other end of the fixing screw is fixedly connected to the connecting rod 408; the fixing screw sequentially penetrates through the spring control device 405, the idle spring cylinder 406, and the toothed nut 407 from top to bottom, and is threadedly connected to the toothed nut 407; the spring control device 405 is fixedly connected to the idle spring cylinder 406, and the idle spring cylinder 406 is fixedly connected to the toothed nut 407; a through hole for the spring 403 to pass through is provided on the spring control device 405 during the up and down movement of the spring control device 405, and the idle spring cylinder 406 is a hollow structure and the hollow structure is used to store the part of the spring 403 that does not play a supporting role; the upper end of the spring 403 is sleeved outside the limiting cylinder 402, and its lower end is sleeved outside the fixing screw, passes through the through hole, and extends into the hollow structure of the idle spring cylinder 406; the cushion block is fixedly connected to the top plate 1, and the connecting rod 408 is fixedly connected to the bottom plate 2; the output gear of the second motor 409 meshes with the toothed nut 407.

[0069] The second motor 409 drives the toothed nut 407 to rotate under the control of the stiffness adjustment instruction, thereby driving the spring control device 405 and the idle spring cylinder 406 to move on the fixing screw. During the movement, the spring 403 passes through the through hole on the spring control device 405, thereby adjusting the actual number of working turns of the spring 403 to change the stiffness of the spring 403. When the optimal stiffness adjustment position (or optimal stiffness value) is reached, the current stiffness adjustment is stopped.

[0070] The spring control device 405 is used to limit the actual number of working turns of the spring 403. The actual number of working turns of the spring 403 refers to the number of turns of the spring 403 between the cushion block and the spring control device 405, and the remaining number of turns of the spring 403 that do not play a supporting role are stored in the idle spring cylinder 406. The through hole is a small hole. During the movement or stiffness adjustment process, the through hole allows the spring 403 to move in the through hole under the drive of the toothed nut 407, changing the actual number of working turns of the spring 403; during the non-movement process, the movement of the spring 403 in the through hole is restricted, so the actual number of working turns does not change.

[0071] In this embodiment, the limiting cylinder 402, the spring control device 405, the idle spring cylinder 406, the fixing screw, and the connecting rod 408 are all coaxially arranged. The inner diameters of the spring control device 405 and the idle spring cylinder 406 are the same as the outer diameter of the fixing screw, and both are connected to the fixing screw by threads. The limiting cylinder 402 restricts the lateral movement of the spring 403.

[0072] The spacer plays a role in restricting the spring 403. In this embodiment, the spacer is a rubber pad 401, which is compressible and provided with a metal gasket at the bottom. The rubber pad 401 plays a buffering role, and the metal gasket makes the force on the rubber pad 401 more uniform, preventing the rubber pad 401 from being locally squeezed and damaged by the limiting cylinder 402 and the spring 403.

[0073] When the fixing screw has a right-handed thread, rotate the toothed nut 407 counterclockwise. The idle spring cylinder 406 and the spring control device 405 move upward on the fixing screw along with the toothed nut 407, reducing the actual number of working turns of the spring 403 and increasing the stiffness of the vibration isolator. Conversely, the actual number of working turns of the spring 403 can be increased, reducing the stiffness of the vibration isolator.

[0074] In a specific embodiment of the present invention, the intelligent vibration isolator further includes a battery module 8, which is disposed on the bottom plate 2 and is used to provide power to the intelligent vibration isolator when the external power supply is interrupted. The battery can trigger the vibration isolator to self-regulate to a state with good vibration isolation effect under various frequency excitations in the event of a sudden power outage.

[0075] In a specific embodiment of the present invention, the intelligent vibration isolator further includes a remote monitoring center 9 communicatively connected to the signal processor 6. The remote monitoring center 9 evaluates the health status of the intelligent vibration isolator in real time according to the received main frequency information and the 1 / 3 octave band vibration level evaluation result.

[0076] As Figure 4 shown, the embodiment of the present invention also provides a method for adjusting the damping and stiffness of the above-mentioned intelligent vibration isolator, including:

[0077] Step 1: Information acquisition

[0078] When a subway (vibration source) passes under the building (vibration isolation object), the acceleration sensor 5 collects the vibration information of the building when it is externally excited and sends it to the signal processor 6.

[0079] Step 2: Processing and analysis

[0080] The signal processor 6 performs frequency-domain power spectrum analysis on the current vibration information to obtain the main frequency information of the external excitation, determines the frequency range where the main frequency information is located, and performs 1 / 3 octave band vibration level evaluation on the vibration information to obtain the 1 / 3 octave band vibration level evaluation result. The signal processor 6 sends the current main frequency information and the 1 / 3 octave band vibration level evaluation result to the central processor 7 and the remote monitoring center 9.

[0081] Step 3: Adjustment judgment and generation of adjustment instructions

[0082] The central processing unit 7 determines whether damping and stiffness adjustment are needed based on the 1 / 3 octave vibration level evaluation result at the 1 / 3 octave center frequency corresponding to the main frequency information of the external excitation;

[0083] When damping and stiffness adjustment are needed, a damping adjustment command is generated according to the main frequency information of the external excitation and the optimal damping adjustment positions at different 1 / 3 octave center frequencies stored in advance, and a stiffness adjustment command is generated according to the main frequency information of the external excitation and the optimal stiffness adjustment positions at different 1 / 3 octave center frequencies stored in advance.

[0084] Step 4: Adjustment of damping and stiffness

[0085] Under the control of the damping adjustment command, the first motor 307 of the damping adjustment mechanism 3 is driven to work. The first motor 307 drives the rotating gear 306 to rotate under the control of the damping adjustment command, and drives the damping block 304 to move up and down through the rotating gear 306 and the rotating screw 305, so as to adjust the contact area between the damping block 304 and the damping liquid 303 (or the position of the damping block 304 in the damping liquid 303) to change the damping magnitude. When the optimal damping adjustment position (or optimal damping value) is reached, the current damping adjustment is stopped.

[0086] Under the control of the stiffness adjustment command, the second motor 409 of each stiffness adjustment mechanism 4 is driven to work. The second motor 409 drives the toothed nut 407 to rotate under the control of the stiffness adjustment command, so as to drive the spring control device 405 and the idle spring cylinder 406 to move on the fixed screw. During the movement, the spring 403 passes through the through hole on the spring control device 405, so as to adjust the actual working turns of the spring 403 to change the stiffness magnitude. When the optimal stiffness adjustment position (or optimal stiffness value) is reached, the current stiffness adjustment is stopped.

[0087] In order to achieve the optimal adjustment of damping and stiffness by issuing a single adjustment command, without repeatedly adjusting by issuing commands multiple times, the optimal damping adjustment positions and optimal stiffness adjustment positions at different 1 / 3 octave center frequencies are pre-stored in the database of the central processing unit 7 of the present invention. The optimal damping adjustment position can be the optimal position of the damping block in the damping liquid or the optimal position of the rotating screw, and the optimal stiffness adjustment position can be the optimal position of the toothed nut on the fixed screw or the position corresponding to the optimal working turns of the spring.

[0088] In this embodiment, the specific determination process of the optimal damping adjustment positions and optimal stiffness adjustment positions at different 1 / 3 octave center frequencies is as follows:

[0089] Step 3.1: Obtain the vibration information of the vibration isolation object when it is subjected to different external excitations.

[0090] In this embodiment, the acceleration sensor 5 collects the vibration information of the isolator changing with time when the building is subjected to different external excitations, and sends it to the signal processor 6.

[0091] Step 3.2: Perform frequency-domain power spectrum analysis on the vibration information under different external excitations to obtain the main frequency information under each external excitation.

[0092] The signal processor 6 performs frequency-domain power spectrum analysis (PSD) on the vibration information under different external excitations, and finds the main frequency during the current subway excitation by plotting the frequency-domain power spectrum diagram, that is, obtains the main frequency information under each external excitation, as Figure 5 shown. According to the main frequency information under a series of external excitations, the frequency range in which the building is most likely to be subjected to external excitations can be determined, for example, 0.89 - 89.1 Hz.

[0093] Step 3.3: Determine the frequency range (i.e., frequency division range) where the main frequency information is located and the 1 / 3 octave center frequency within this frequency range according to the main frequency information under each external excitation.

[0094] The signal processor 6 determines the frequency range where the main frequency information is located and the 1 / 3 octave center frequency within this frequency range according to the main frequency information under each external excitation, such as the 1 / 3 octave center frequencies and their frequency ranges under 20 different external excitations shown in Table 1.

[0095] Table 1 1 / 3 octave center frequencies and their frequency ranges (Hz)

[0096]

[0097]

[0098] The main frequency of the subway excitation in each acquisition period can determine the corresponding frequency range, each frequency range corresponds to a 1 / 3 octave center frequency, each 1 / 3 octave center frequency is used as the main frequency of the corresponding subway excitation, and the 1 / 3 octave center frequency is used as the basis for how to adjust the damping and stiffness.

[0099] Step 3.4: Use the vibration isolation theory and experimental method to determine the optimal damping adjustment position and the optimal stiffness adjustment position at each 1 / 3 octave center frequency, that is, to which position the damping block 304 in the damping adjustment mechanism 3 should be adjusted (the position of the damping block 304 in the damping liquid 303), and to which position the toothed nut 407 in the stiffness adjustment mechanism 4 should be adjusted (adjust the actual number of working turns of the spring 403) to achieve the best vibration isolation effect.

[0100] The intelligent vibration isolator of the present invention is used for building vibration isolation. That is, during the operation of the subway under the building, vibrations will be generated, which will affect the movement of the building foundation, and the movement of the foundation will in turn cause vibrations of the building above the foundation. Therefore, the vibration of the building belongs to forced vibration under foundation excitation. The absolute motion transmissibility T of forced vibration under simple harmonic foundation excitation is as follows: d as follows:

[0101]

[0102] where ζ is the damping ratio, C is the damping of the system composed of the intelligent vibration isolator and the building structure, C c is the critical damping, r is the frequency ratio, ω is the frequency of external excitation, ω n is the natural frequency of the system composed of the intelligent vibration isolator and the building structure.

[0103] From Equation (1), the relationship diagram of the absolute motion transmissibility and the frequency ratio as shown in Figure 6 is plotted. Since the intelligent vibration isolator is used for the flexible connection between the building and the foundation, the natural frequency ω of the system composed of the vibration isolator and the building can be changed by adjusting the stiffness of the vibration isolator. n . From Figure 6 it can be seen that when T d ≈0, it indicates that the foundation movement is isolated by the intelligent vibration isolator. Reducing the stiffness will reduce the natural frequency ω n . The more the natural frequency ω n is reduced, the greater the frequency ratio is than , and the better the vibration isolation effect. However, the larger static displacement brought to the vibration isolator and the building structure after reducing the stiffness also needs to be considered. Therefore, the stiffness value corresponding to the frequency ratio needs to be determined through experiments.

[0104] When , the smaller the damping ratio (the increase of the damping ratio will reduce the vibration isolation effect), the lower the absolute motion transmissibility, and the better the vibration isolation effect (in this regard, the smaller the damping C or the damping ratio, the better). However, in the vibrations generated during the actual operation of the subway, in addition to the main frequency, there are also vibrations of other frequencies. The vibrations of this part of the frequencies may cause resonance of the system composed of the vibration isolator and the isolated building (in this regard, the larger the damping C or the damping ratio, the better). In order to reduce the amplitude when the vibration isolator passes through the resonance region (that is, the region within the frequency ratio range of 0 to 1.5 in Figure 6 ), it is necessary to configure appropriate damping for the vibration isolator through experimental tests. The value of the damping C under the main frequency of the external excitation is mainly based on the vibration isolation effect (vibration level evaluation) during the experiment.

[0105] Therefore, the specific implementation process of using vibration isolation theory and experimental method to determine the optimal damping adjustment position and the optimal stiffness adjustment position at each 1 / 3 octave center frequency is as follows:

[0106] At each 1 / 3 octave center frequency, the damping of the vibration isolator is adjusted by adjusting the damping adjustment mechanism 3, thereby adjusting the damping ratio When the damping ratio ζ is [value], the experimental method is used in combination with the vibration isolation effect to determine the optimal position of the damping block 304 in the damping liquid 303 (or the optimal position of the rotating screw 305) in the damping adjustment mechanism 3, and this optimal position is the optimal damping adjustment position;

[0107] At each 1 / 3 octave center frequency, the stiffness of the vibration isolator is adjusted by adjusting the stiffness adjustment mechanism 4, thereby adjusting the frequency ratio When the frequency ratio is [value], the experimental method is used in combination with the vibration isolation effect to determine the optimal position of the toothed nut 407 on the fixed screw (or the actual number of working turns of the spring 403) in the stiffness adjustment mechanism 4, and this optimal position is the optimal stiffness adjustment position.

[0108] Based on the vibration isolation theory, the stiffness scale value (i.e., the scale position where the toothed nut 407 is located) and the damping scale value (i.e., the scale position where the rotating screw 305 is located) corresponding to the natural frequency of the building that can effectively isolate the vibration of the building under the subway excitation at each 1 / 3 octave center frequency and its frequency range are pre-determined. The vibration isolation effect can use the vibration level evaluation result as a reference index.

[0109] During the vibration level evaluation, first determine the frequency range (i.e., the frequency division range) according to the main frequency, then determine the corresponding 1 / 3 octave center frequency according to the frequency range, and finally determine the vibration level at the 1 / 3 octave center frequency, that is, obtain the 1 / 3 octave vibration level evaluation result diagram, as Figure 7 shown. To improve the service life of the vibration isolator, it is not necessary to adjust every time the subway passes by the building or the acceleration sensor 5 collects vibration information each time. To make the adjustment more clear, it is necessary to first judge whether adjustment is needed according to the vibration level evaluation result (i.e., the vibration level at the 1 / 3 octave center frequency corresponding to the main frequency).

[0110] In this embodiment, when the vibration level evaluation result corresponding to the 1 / 3 octave center frequency in the current detection period (i.e., the maximum vibration level in the frequency division corresponding to the 1 / 3 octave center frequency) exceeds the pre-set threshold, it indicates that damping and stiffness adjustment are required, and the central processor 7 generates a damping adjustment instruction and a stiffness adjustment instruction to perform the adjustment; otherwise, damping and stiffness adjustment are not required. In this embodiment, the threshold is 70 dB.

[0111] The vertical vibration levels involved in the judgment of whether adjustment is required include vibration acceleration level, Z vibration level, and maximum vibration level of frequency division.

[0112] Vibration acceleration level L a is:

[0113]

[0114] In the formula: a rms is the effective value of vibration acceleration, unit: m / s 2 ; a 0 is the reference acceleration.

[0115] Z vibration level VL: According to the provisions of ISO2631-1, the vibration acceleration level obtained after correcting the whole-body vibration by different frequency weighting factors is simply called the Z vibration level, denoted as VL, and the unit is dB. The calculation formula of the Z vibration level VL is:

[0116]

[0117] In the formula, a 0 is the reference acceleration, a r ′ ms is the effective value of the corrected vibration acceleration (m / s 2 ).

[0118] Maximum vibration level of frequency division: The maximum vibration level of frequency division VLmax is the maximum vibration acceleration level corresponding to the center frequency of the 1 / 3 octave (obtained after correcting by the Z weighting factor). The center frequency of the 1 / 3 octave and its frequency range are shown in Table 1.

[0119] Whenever a subway passes under a building, the acceleration sensor 5 on the bottom plate 2 collects data once (continuous collection within a certain detection period) and transmits the data to the signal processor 6 for frequency power spectrum analysis and 1 / 3 octave band vibration level evaluation. The main frequency information and vibration level evaluation results of the subway vibration excitation obtained from the frequency domain analysis and vibration level evaluation are transmitted to the central processor 7 in real time and compared with its database. The main frequency information of the vibration is based on the 1 / 3 octave band center frequency (taking the center frequency within the same 1 / 3 octave band range as the reference value). According to the pre-stored optimal damping adjustment position and optimal stiffness adjustment position corresponding to each 1 / 3 octave band center frequency, damping adjustment instructions and stiffness adjustment instructions corresponding to the main frequency obtained from each frequency domain analysis can be obtained. If the vibration level evaluation result of the subway excitation frequency received by the vibration isolator within the 1 / 3 octave band center frequency and its frequency range exceeds the preset threshold (such as 70 dB), the central processor 7 issues adjustment instructions to each motor. After receiving the instructions from the central processor 7, the first motor 307 rotates accordingly, driving the meshing rotating gear 306, so that the rotating screw 305 moves up and down at the central thread of the bottom plate 2 of the upper support cylinder 301. The lower end of the rotating screw 305 is fixedly connected to the adjustment damping block 304. Therefore, the rotation of the first motor 307 realizes the up and down movement of the damping block 304 to change the depth of the adjustment damping block 304 immersed in the damping liquid 303, thereby changing the contact area between the two and realizing the adjustment of the damping characteristics; the second motor 409 drives the toothed nut 407 to rotate and move up and down on the fixed screw, and cooperates with the spring control device 405 to control the spring 403, realizing the change of the actual working turns of the spring 403, thereby changing the stiffness characteristics of the vibration isolator.

[0120] The specific embodiments disclosed above are only for the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or variations, which should all be covered within the protection scope of the present invention.

Claims

1. An intelligent vibration isolator is provided between the object to be vibration-isolated and its foundation. Characterized in that: The intelligent vibration isolator includes: A top plate and a bottom plate; A damping adjustment mechanism, one end of which is connected to the center of the lower end face of the top plate, and the other end is connected to the center of the upper end face of the bottom plate. The damping adjustment mechanism adjusts the damping in real time under the damping adjustment instruction of the central processor; At least four stiffness adjustment mechanisms, a plurality of the stiffness adjustment mechanisms are located between the top plate and the bottom plate and are evenly distributed around the damping adjustment mechanism. Each stiffness adjustment mechanism adjusts the stiffness in real time under the stiffness adjustment instruction of the central processor; An acceleration sensor for collecting vibration information of the object to be vibration-isolated when it is subjected to external excitation; A signal processor for performing frequency-domain power spectrum analysis on the vibration information collected by the acceleration sensor to obtain the main frequency information of the external excitation, and performing 1 / 3 octave band vibration level evaluation on the frequency range where the main frequency information is located to obtain the 1 / 3 octave band vibration level evaluation result; A central processor for storing the optimal damping adjustment positions of the damping adjustment mechanism at different 1 / 3 octave band center frequencies and the optimal stiffness adjustment positions of each stiffness adjustment mechanism at different 1 / 3 octave band center frequencies; judging whether damping and stiffness adjustment are required according to the 1 / 3 octave band vibration level evaluation result; when damping and stiffness adjustment are required, generating a damping adjustment instruction according to the optimal damping adjustment position at different 1 / 3 octave band center frequencies and the main frequency information sent by the signal processor, and generating a stiffness adjustment instruction according to the optimal stiffness adjustment position at different 1 / 3 octave band center frequencies and the main frequency information sent by the signal processor; Wherein, the damping adjustment mechanism includes an upper support cylinder, a damping cylinder, damping liquid, a damping block, a rotating screw, a rotating gear and a first motor; an upper support cylinder is provided on the damping cylinder, the damping cylinder is filled with damping liquid, the damping block is arranged in the damping cylinder and one end thereof is connected to the rotating gear through the rotating screw; the rotating gear meshes with the output gear of the first motor, and the first motor and the rotating gear are arranged in the upper support cylinder; the top end of the upper support cylinder is fixedly connected to the center of the lower end face of the top plate, and the bottom end of the damping cylinder is connected to the center of the upper end face of the bottom plate; The first motor drives the damping block to move up and down through the rotating gear and the rotating screw under the control of the damping adjustment instruction, adjusts the contact area between the damping block and the damping liquid to change the damping value, and further reaches the optimal damping adjustment position.

2. The intelligent vibration isolator according to claim 1, Characterized in that: The outer diameter of the upper support cylinder is adapted to the inner diameter of the damping cylinder, so that the lower part of the upper support cylinder is embedded in the damping cylinder and can slide relatively.

3. The intelligent vibration isolator according to claim 1, Characterized in that: The damping block is in a cylindrical shape and has spiral grooves on its outer surface.

4. The intelligent vibration isolator according to claim 1, Characterized in that: Each of the stiffness adjustment mechanisms includes a cushion block, a limit cylinder, a spring, a fixing screw, a spring control device, an idle spring cylinder, a toothed nut, a connecting rod, and a second motor; the limit cylinder is fixedly arranged at the bottom of the cushion block, and the bottom of the limit cylinder is fixedly connected to one end of the fixing screw, and the other end of the fixing screw is fixedly connected to the connecting rod; the fixing screw sequentially penetrates through the spring control device, the idle spring cylinder, and the toothed nut from top to bottom, and is threadedly connected to the toothed nut; the spring control device is fixedly connected to the idle spring cylinder, and the idle spring cylinder is fixedly connected to the toothed nut; A through hole for the spring to pass through is provided on the spring control device during the up and down movement of the spring control device. The idle spring cylinder is a hollow structure, and the hollow structure is used to store the part of the spring that does not play a supporting role; the upper end of the spring is sleeved outside the limit cylinder, and its lower end is sleeved outside the fixing screw and passes through the through hole and extends into the hollow structure of the idle spring cylinder; the cushion block is fixedly connected to the top plate, and the connecting rod is fixedly connected to the bottom plate; The output gear of the second motor meshes with the toothed nut. The second motor drives the spring control device and the idle spring cylinder to move on the fixing screw through the toothed nut under the control of the stiffness adjustment instruction, adjusts the actual working turns of the spring to change the stiffness value, and further reaches the optimal stiffness adjustment position.

5. The intelligent vibration isolator according to claim 4, characterized in that: The limit cylinder, the spring control device, the idle spring cylinder, the fixing screw, and the connecting rod are all coaxially arranged.

6. The intelligent vibration isolator according to claim 4, characterized in that: The cushion block is a rubber pad, the rubber pad is compressible, and a metal gasket is provided at the bottom.

7. The intelligent vibration isolator according to any one of claims 1 to 6, characterized in that: The acceleration sensor, the signal processor, and the central processor are all arranged on the bottom plate.

8. The intelligent vibration isolator according to claim 1, characterized in that: The sampling time interval of the acceleration sensor is the time interval when adjacent vibration sources pass through the bottom of the vibration-isolated object.

9. The intelligent vibration isolator according to claim 1, characterized in that: The intelligent vibration isolator further includes a battery module, and the battery module is used to provide power for the intelligent vibration isolator when the external power supply is interrupted.

10. The intelligent vibration isolator according to claim 1, characterized in that: The intelligent vibration isolator further includes a remote monitoring center communicatively connected to the signal processor.

11. A damping and stiffness adjustment method for the intelligent vibration isolator according to any one of claims 1 to 10, characterized in that, comprises the following steps: Obtain the vibration information of the vibration-isolated object when it is subjected to external excitation; Perform frequency-domain power spectrum analysis on the vibration information to obtain the main frequency information of the external excitation, and perform 1 / 3 octave band vibration level evaluation on the vibration information to obtain the 1 / 3 octave band vibration level evaluation result; Judge whether damping and stiffness adjustment are required according to the vibration level evaluation result at the 1 / 3 octave center frequency corresponding to the main frequency information of the external excitation; When damping and stiffness adjustment are required, a damping adjustment command is generated according to the main frequency information of the external excitation and the optimal damping adjustment positions at different 1 / 3 octave center frequencies stored in advance, and a stiffness adjustment command is generated according to the main frequency information of the external excitation and the optimal stiffness adjustment positions at different 1 / 3 octave center frequencies stored in advance; Under the control of the damping adjustment command, the first motor of the damping adjustment mechanism is driven to work to adjust the damping in real time; Under the control of the stiffness adjustment command, the second motors of each stiffness adjustment mechanism are driven to work to adjust the stiffness in real time.

12. The damping and stiffness adjustment method of the intelligent vibration isolator according to claim 11, characterized in that, The specific determination process of the optimal damping adjustment positions and the optimal stiffness adjustment positions at different 1 / 3 octave center frequencies is as follows: Obtain the vibration information of the vibration isolation object when it is subjected to different external excitations; Perform frequency-domain power spectrum analysis on the vibration information when there are different external excitations to obtain the main frequency information for each external excitation; Determine the frequency range where the main frequency information is located and the 1 / 3 octave center frequencies within this frequency range according to the main frequency information for each external excitation; Use vibration isolation theory and experimental methods to determine the optimal damping adjustment positions and the optimal stiffness adjustment positions at each 1 / 3 octave center frequency.

13. The damping and stiffness adjustment method of the intelligent vibration isolator according to claim 12, characterized in that, The specific implementation process of using vibration isolation theory and experimental methods to determine the optimal damping adjustment positions and the optimal stiffness adjustment positions at each 1 / 3 octave center frequency is as follows: At each 1 / 3 octave center frequency, the damping ratio is adjusted by adjusting the damping adjustment mechanism When the damping ratio ζ is 0.04 - 0.06, combined with the vibration isolation effect, the optimal position of the damping block in the damping liquid in the damping adjustment mechanism is determined, and this optimal position is the optimal damping adjustment position; where C is the damping of the system composed of the intelligent vibration isolator and the object to be vibration isolated, C c is the critical damping; At each 1 / 3 octave center frequency, the frequency ratio is adjusted by adjusting the stiffness adjustment mechanism When the frequency ratio is reached, the optimal position of the toothed nut in the stiffness adjustment mechanism on the fixed screw is determined in combination with the vibration isolation effect, and this optimal position is the optimal stiffness adjustment position; where ω is the frequency of the external excitation, and ω n is the natural frequency of the system composed of the intelligent vibration isolator and the vibration-isolated object.

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