CN110259877B - Composite dynamic vibration absorber and control method thereof - Google Patents
Composite dynamic vibration absorber and control method thereof Download PDFInfo
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- CN110259877B CN110259877B CN201910430639.6A CN201910430639A CN110259877B CN 110259877 B CN110259877 B CN 110259877B CN 201910430639 A CN201910430639 A CN 201910430639A CN 110259877 B CN110259877 B CN 110259877B
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- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/002—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion characterised by the control method or circuitry
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- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/005—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion using electro- or magnetostrictive actuation means
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- F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
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Abstract
The invention discloses a composite dynamic vibration absorber and a control method thereof, the composite dynamic vibration absorber comprises a variable mass and variable rigidity module, a signal acquisition unit and a control unit, wherein the variable rigidity module comprises two piezoelectric ceramic pieces and a piezoelectric ceramic external circuit, the piezoelectric ceramic external circuit is fixed in the variable rigidity module by a connecting block, the output end of the piezoelectric ceramic external circuit is connected with the upper surface and the lower surface of the piezoelectric ceramic pieces, the input end of the piezoelectric ceramic external circuit is connected with an electronic connector, and the variable mass module comprises a liquid storage tank, a liquid pump and a liquid lower cavity which are connected through a hose. The design structure is simple, the vibration reduction effect in the vibration reduction bandwidth is good, the effective vibration reduction frequency band is wide, the performance is stable, the control response time is short, and the practical value is very high; the defect that the active dynamic vibration absorber excessively depends on external energy is overcome.
Description
Technical Field
The invention belongs to the technical field of vibration control, relates to a vibration absorber, and particularly relates to a composite dynamic vibration absorber with continuously-changed mass and rigidity and a control method thereof, namely a dowel bar construction quality detection method.
Background
Due to the advantages of simple structure, good economical efficiency, stable performance and the like, the dynamic vibration absorber is widely applied to the vibration control fields of mechanical systems, engineering structures, bridges, buildings and the like. For the traditional dynamic vibration absorber, when the natural frequency of the vibration absorber is equal to the external excitation frequency omega, the vibration absorber can effectively reduce the vibration of a main system, but the structural parameters of the traditional dynamic vibration absorber cannot be changed, the natural frequency cannot be adjusted, the effective vibration reduction frequency band is too narrow, and when the external excitation frequency omega deviates from the natural frequency of the vibration absorber, the vibration reduction performance of the traditional dynamic vibration absorber is greatly reduced. The active dynamic vibration absorber can solve the problem of narrow vibration reduction frequency band and effectively reduce vibration in a wider frequency band. However, the active dynamic vibration absorber requires a large amount of external energy, has high cost and a complex structure, and loses the vibration damping performance and may aggravate the vibration of the main system when the adjustment is not proper. The invention patent with the domestic patent number of 96107066.8 is the passive vibration absorber. The vibration absorption frequency band is too narrow, and the vibration absorption frequency band can be widened only by increasing the damping or the mass of the vibration absorber and adopting a method of a plurality of vibration absorption blocks. However, theories prove that increasing the damping reduces the vibration damping performance of the vibration absorber, and the frequency band widening is not obvious; the structure is heavy due to the increased weight, and the increase of the number of the vibration absorbers is not practical due to space limitation and the like. The utility model with the domestic patent number of 942016820.1 mentions a combined active control vibration absorber. The principle is that the active control force is added on the basis of the passive vibration absorber, but the natural frequency of the vibration absorber is still not adjustable, the more far the external excitation frequency omega deviates from the natural frequency of the vibration absorber, the larger the required active control force is, so the design seriously depends on the external energy, the realization cost is high, and the practicability is poor.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a composite dynamic vibration absorber and a control method thereof, which solve the technical problems that the effective vibration attenuation frequency band of the conventional passive vibration absorber is too narrow, or the natural frequency of the vibration absorber is not adjustable although the vibration attenuation frequency band of the active vibration absorber is widened, a large amount of external energy is needed, the cost is high and the structure is complex.
The technical scheme adopted by the invention is as follows:
a composite dynamic vibration absorber comprises a main system, a vibration absorber positioned on the main system, a signal acquisition unit and a control unit; the vibration absorber comprises a variable stiffness module and a variable mass module positioned at the upper part of the variable stiffness module; the variable stiffness module comprises piezoelectric ceramics and an external circuit connected with the piezoelectric ceramics in parallel, and the external circuit comprises a relay and a capacitor connected with the relay in series; the control unit controls the on-off of the external circuit relay according to the external excitation frequency acquired by the signal acquisition unit to change the capacitance value of the piezoelectric ceramic, so that the rigidity of the vibration absorber is changed; meanwhile, the control unit changes the mass of the mass-changing module according to the external excitation frequency acquired by the signal acquisition unit, so that the mass of the vibration absorber is changed; the natural frequency of the vibration absorber is changed through the rigidity change of the rigidity changing module and the mass change of the mass changing module, so that the natural frequency synchronously adapts to the external excitation frequency of the composite type dynamic vibration absorber.
Preferably, the variable stiffness module further comprises an electronic connector, an output end of the external circuit is connected with the piezoelectric ceramic in parallel, and an input end of the external circuit is connected with the electronic connector.
In addition, the rigidity-variable module further comprises a connecting block, an external circuit is fixed on the rigidity-variable module through the connecting block, the outer sides of the piezoelectric ceramics are respectively and rigidly connected with the top cover and the bottom cover, the top cover and the bottom cover are fixed through the shell, and the connecting blocks are respectively arranged on the outer sides of the top cover and the bottom cover.
Preferably, the variable mass module comprises a fixed mass unit and a variable mass unit located on the fixed mass unit; the variable mass unit comprises an actuating mechanism, the actuating mechanism comprises a liquid tank and a water pump connected with the liquid tank, and the mass of the liquid entering the liquid tank is controlled by the water pump to realize the mass change of the variable mass unit; the water pump is connected with the output end of the control unit at the same time.
More preferably, the liquid tank is divided into an upper air cavity and a lower liquid cavity, the upper air cavity and the lower liquid cavity are separated by a piston, the piston is mounted on a guide rod, the guide rod is vertically positioned in the middle of the liquid tank, and an air outlet is processed on the upper side of the liquid tank.
As a further preferable scheme of the executing mechanism, the executing mechanism further comprises a liquid storage tank, the liquid storage tank is connected with a water pump through a hose, and the water pump is connected with the liquid storage tank.
Preferably, the signal acquisition unit comprises a flow sensor, a charge amplifier, a controllable power supply and an acceleration sensor positioned on the fixed mass unit, and the output end of the acceleration sensor is connected with the input end of the charge amplifier; the output ends of the charge amplifier and the flow sensor are connected with the input end of the control unit; the output end of the control unit is connected with the controllable power supply and the variable mass module, the output end of the controllable power supply is connected with the electronic connector, the charge amplifier receives an acceleration signal transmitted by the acceleration sensor, converts the acceleration signal into a charge signal and transmits the charge signal to the control unit, and the control unit obtains the external excitation frequency through the received charge signal.
The invention also provides a control method of the composite dynamic vibration absorber, which adopts the following stepsObtaining the mass m required by the vibration absorber through the external excitation frequency omega2And stiffness k2(ii) a The control unit is based on the acquired k2Obtaining the voltage required by the piezoelectric ceramics, and adjusting the size of a capacitor incorporated in the piezoelectric ceramics according to the required voltage; the control unit is based on the acquired m2Value controlling the mass of liquid entering the liquid tank;
wherein the minimum value and the maximum value of the rigidity of the variable rigidity module are respectively kmin、kmaxThe mass minimum value and the mass maximum value of the variable mass module are respectively mmin、mmax。
The invention has the beneficial effects that:
1. the composite dynamic vibration absorber has continuously changed mass and rigidity, further widens the effective vibration attenuation frequency band of the vibration absorber on the basis of the existing self-adaptive vibration absorber by adjusting two parameters of the rigidity and the mass of the vibration absorber, has obvious vibration attenuation effect, and can effectively attenuate vibration of a main system under the condition that the vibration frequency of the main system is basically stable.
2. The composite dynamic vibration absorber has less energy consumption, and the design only needs to provide the voltage for changing the relay of the piezoelectric ceramic external circuit and the current required by the water pump during working, thereby greatly reducing the energy required by active control.
3. According to the composite dynamic vibration absorber, the actuating mechanism adjusts the natural frequency of the vibration absorber according to the signal acquisition unit and the control system, so that the vibration absorber is simple in structure, the control method is easy to implement, and the system reliability is high. The vibration absorber has the advantages that the rigidity is changed by adopting the piezoelectric ceramics, the vibration control response speed is high, the rigidity and the mass are simultaneously adjusted, the natural frequency of the vibration absorber can be quickly adjusted, and the control response time is greatly shortened.
4. The control method of the composite dynamic vibration absorber is based on the vibration absorber structure of the invention, and the adjustment reliability is high by adjusting two parameters of the rigidity and the mass of the vibration absorber. The design adopts dual-system independent control, and the variable stiffness module and the mass adjustable unit are mutually independent, so that when a certain unit breaks down, the defect that the adjustment performance of the vibration absorber is lost completely can be avoided, and the performance is more stable.
Drawings
FIG. 1 is a schematic structural diagram of a composite dynamic vibration absorber according to the present invention;
FIG. 2 is a schematic structural diagram of a variable stiffness module according to the present invention;
FIG. 3 is a schematic diagram of a piezoelectric ceramic external circuit of the variable stiffness module according to the present invention;
FIG. 4 is a schematic view of a liquid tank of the present invention;
FIG. 5 is a graph of the amplitude-frequency characteristics of the controlled system of the present invention;
fig. 6 is a graph showing the magnitude of the external capacitance and the stiffness of the piezoelectric ceramic sheet according to the present invention.
In the figure, 1 is a main system, 2 is a variable stiffness module, 3 is a fixed mass unit, 4 is a liquid tank, 5 is a controllable power supply, 6 is a controller, 7 is a charge amplifier, 8 is a liquid storage tank, 9 is an acceleration sensor, 10 is a hose, 11 is a water pump, 12 is a flow sensor, 13 is piezoelectric ceramic, 14 is an electronic connector, 15 is a top cover, 16 is a shell, 17 is a connecting block, 18 is a bottom cover, 19 is a lead, 20 is an external circuit, 22 is a relay, 23 is a capacitor, 24 is an air outlet, 25 is a piston, 26 is an upper air cavity, 27 is a lower liquid cavity, and 28 is a guide rod.
Detailed Description
The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention. The components and structures of the product (device) used in the embodiments of the present invention particularly describe the functions and functions of the components, respectively, and the interrelation between the components, such as the connection relationship, the condition that signals (information) are processed and transmitted by each module, and the trend of the acted signals (information). The embodiments are described in such full, clear, to enable one of ordinary skill in the art to understand/implement the present patent without the need for inventive effort. And to explain why the objects of the present invention can be achieved by the above-described technical solutions. The object of the invention is also achieved by providing further alternatives. The substitution here may be of a partial structure, a device, a module, or may be of an overall technical solution.
Example 1:
the embodiment provides a compound dynamic vibration absorber, and its quality and rigidity change in succession mainly includes: the vibration absorber comprises a main system, a vibration absorber, a signal acquisition unit and a control unit, wherein the vibration absorber, the signal acquisition unit and the control unit are positioned on the main system, and the control unit adopts a controller 6. The vibration absorber comprises a variable stiffness module 2 and a variable mass module which are arranged on a vibrating object, namely a main system, wherein the variable stiffness module 2 is provided with a fixed mass unit 3 and a variable mass unit, the fixed mass unit 3 is provided with a liquid tank 4, and the liquid tank 4 is connected with a water supply device; the variable stiffness module 2 comprises two pieces of piezoelectric ceramics 13 and a piezoelectric ceramic external circuit 20, the piezoelectric ceramic external circuit 20 is fixed in the variable stiffness module 2 through a connecting block 17, the output end of the piezoelectric ceramic external circuit 20 is connected with the piezoelectric ceramic pieces 13 in parallel through a lead 19, and the input end of the external circuit 20 is connected with the electronic connector 14; the outer sides of the two piezoelectric ceramic plates 13 are respectively and rigidly connected with a top cover 15 and a bottom cover 18, the top cover 15 and the bottom cover 18 are fixed by a shell 16, the outer sides of the top cover 15 and the bottom cover 18 are respectively provided with a connecting block 17 for connecting the main system 1 and the fixed quality unit 3, and an electronic connector 14 on the shell 16 is connected with the output end of the controllable power supply 5.
The signal acquisition unit comprises an acceleration sensor 9, a flow sensor 12 and a charge amplifier 7, wherein the acceleration sensor 9 is arranged on the fixed mass unit 3 and used for acquiring vibration signals of the absorber; the output end of the acceleration sensor 9 is connected with the input end of the charge amplifier 7, the output ends of the charge amplifier 7 and the flow sensor 12 are connected with the input end of the controller 6, the output end of the controller 6 is connected with the controllable power supply 5 and the water supply device, and the output end of the controllable power supply 5 is connected with the electronic connector 14.
The variable mass unit comprises a water pump 11 and a liquid storage tank 8; the liquid tank 4 is connected with a water pump 11 through a hose, the water pump 11 is connected with the liquid storage tank 4, and the other end of the water pump 11 is connected with the output end of the controller 6. The liquid box 4 is divided into an upper air cavity 26 and a lower liquid cavity 27, the middle of the upper air cavity 26 and the lower liquid cavity 27 is separated by a piston 25, the piston is arranged on a guide rod 28, and an air outlet 24 is formed in the upper side of the liquid box 4.
The present invention utilizes the piezoelectric ceramics 13 as the elastic element of the vibration absorber, and the mass of the vibration absorber is divided into the mass of the fixed mass unit 3 and the mass of the liquid tank 4. The natural frequency of the vibration absorber is adjusted by changing the stiffness of the piezoelectric ceramics 13 and changing the effective mass of the vibration absorber. The vibration signal of the main system 1 is acquired by the acceleration sensor 9 and is transmitted to the controller 6 through the charge amplifier 7, the controller 6 is a computer, the controller 6 performs fast Fourier transform on the signal to obtain the external excitation frequency omega of the main system 1, a control signal is sent out accordingly, the voltage of the controllable power supply 5 is controlled to change the on-off condition of the relay 22, the size of the capacitor 23 incorporated into the piezoelectric ceramic piece 13 is changed, the rigidity of the piezoelectric ceramic piece 13 is changed, meanwhile, the water pump 11 is controlled to pump in or out liquid, and the flexible pipe 10 is attached with the liquid flow sensor 12 to feed back liquid flow information in real time. Through the adjustment of the stiffness and the mass of the vibration absorber, the natural frequency of the vibration absorber is quickly changed, so that the tracking of the external vibration excitation frequency omega is realized, and the optimal vibration attenuation is achieved.
The invention also provides a control method of the composite dynamic vibration absorber with continuously changed mass and rigidity, which comprises the following steps:
1) acquiring external excitation frequency omega of the composite dynamic vibration absorber according to the acceleration sensor;
2) vibration damping frequency band of
Within this vibration damping frequency band, the stiffness of the fixed mass unit is defined by kminContinuously increase to kmaxMass is given by mmaxContinuously decrease to mmin. Namely, it is
In the formula
For the maximum frequency within the damping bandwidth,
is the minimum frequency within the damping bandwidth. k is a radical ofe1Is the rate of change of stiffness, k, of the vibration absorbere2Is the rate of change of the mass of the vibration absorber.
3) Making the stiffness vary continuously and linearly, i.e. ke1As a constant, the rate of change of stiffness within the damping bandwidth is:
4) ensuring that the excitation frequency omega is equal to the natural frequency of the composite dynamic vibration absorber, i.e.
5) The rate of change of the mass of the vibration absorber can be found to be:
the control of the stiffness and mass of the vibration absorber takes the following control strategy:
6) the controller 6 calculates the stiffness of the composite dynamic vibration absorber required by calculation according to the obtained external excitation frequency omega of the composite dynamic vibration absorber and a control method corresponding to a vibration attenuation frequency band, determines the voltage required to be applied according to the relation between the stiffness required by the vibration absorber and the voltage, transmits a control signal to the controllable power supply 5 according to the voltage required to be applied, and the controllable power supply 5 receives the control signal and then adjusts the voltage transmitted to the piezoelectric ceramic electronic connector 14, and then controls the on-off state of the relay 22 in the piezoelectric ceramic external circuit 20. When the required rigidity of the variable rigidity module 2 is calculated, the mass of the liquid tank 4 required to be achieved is calculated and obtained to control the water pump 11 to pump liquid into or out of the liquid tank 4 according to the size of the vibration excitation frequency omega, and the change of the vibration excitation frequency omega can be tracked in the vibration attenuation bandwidth through the change of the mass and the rigidity.
The required stiffness K of the absorber referred to above is related to the capacitance C incorporated:
wherein K is the rigidity of the piezoelectric ceramic piece, KEThe rigidity of the short circuit of the piezoelectric ceramic piece is shown, C is the total capacitance of an external circuit,
kp is the coupling coefficient of the piezoelectric ceramic.
The magnitude of the external capacitance value and the rigidity of the piezoelectric ceramic 13 are shown in fig. 6. The relay 22 and the capacitor 23 are designed to have proper values, so that when the controllable power supply 5 outputs different voltages, the on-off state of the relay 22 can be changed, the external circuit incorporated in the piezoelectric ceramic piece 13 is changed, and the actual rigidity of the rigidity changing module 2 is changed.
Compared with the existing variable-stiffness vibration absorber and variable-mass vibration absorber, the design further widens the effective vibration reduction frequency band, and has important engineering application value.
The basic idea of the invention is to use the piezoelectric ceramic 13 as an elastic element and adjust the rigidity by changing the capacitance value in the external circuit 20 of the piezoelectric ceramic; the amount of liquid in the liquid tank 4 of the vibration absorber is used to change the effective mass of the vibration absorber and ultimately the natural frequency of the vibration absorber.
The working principle is briefly described as follows: from the foregoing, the vibration absorber natural frequency is
Wherein m is2And k2Respectively the effective mass and stiffness of the vibration absorber. Let the minimum stiffness of the vibration absorber, i.e. the stiffness without voltage applied, be kminThe maximum stiffness, i.e. the stiffness at which the applied voltage is at a maximum in the effective range, is kmax(ii) a Minimum value of variable mass is mminMaximum value of mmax. According to the calculation formula of the natural frequency of the vibration absorber, the minimum and maximum natural frequencies of the design are respectively
Therefore, the effective vibration damping frequency band of the invention is
Compared with the existing self-adaptive vibration absorber, the self-adaptive vibration absorber can simultaneously adjust the numerator and the denominator in the natural frequency relational expression, and further improves the range of effective vibration reduction frequency. When the external excitation frequency omega of the main system 1 changes, the acceleration sensor 9 transmits the collected signal to the controller 6 through the charge amplifier 7, the controller 6 performs certain mathematical transformation on the signal to obtain the external excitation frequency omega, the controller 6 calculates the required rigidity of the vibration absorber according to the control strategy corresponding to the vibration reduction frequency band, determines the required applied voltage according to the relation between the rigidity and the voltage required by the vibration absorber, transmits the control signal to the controllable power supply 5, the controllable power supply 5 receives the control signal and then adjusts the voltage transmitted to the piezoelectric ceramic electronic connector 14, and then controls the on-off state of the relay 22 in the piezoelectric ceramic external circuit 20, because the piezoelectric ceramic external circuit 20 and the piezoelectric ceramic piece 13 are controlled to be connected in parallel, the on-off state of the relay 22 determines the size of the capacitor 23 incorporated in the piezoelectric ceramic piece 13, and then changes the rigidity of the piezoelectric ceramic piece 13, so that the variable stiffness module 2 achieves the desired stiffness. The rigidity of the variable rigidity module 2 is calculated and the rigidity of the liquid tank 4 is calculatedThe mass controls the water pump 11 to pump liquid into or out of the liquid tank 4, and the change of the excitation frequency omega can be tracked in the vibration damping bandwidth through the change of the mass and the rigidity, so that the optimal vibration damping of the composite dynamic vibration absorber is achieved.
Claims (7)
1. A control method of a composite dynamic vibration absorber is characterized by comprising the following steps and a mathematical formula:
1) acquiring a main system vibration acceleration signal by using an acceleration sensor, analyzing the signal by using a signal processing method, and acquiring the motion frequency of a main system and a composite dynamic vibration absorber, wherein the frequency is the external excitation frequency omega of the main system;
2) from the mass and rigidity parameters of the composite dynamic vibration absorber, the vibration reduction frequency band of the vibration absorber is known to be
Within the damping frequency band, the rigidity of the composite dynamic vibration absorber is made to be kminChange to kmaxMass is given by mmaxContinuously decrease to mminI.e. by
In the formula
For the maximum frequency within the damping band,
to a minimum frequency within the damping band, ke1Is the rate of change of stiffness, k, of the vibration absorbere2Is the rate of change of the mass of the absorber;
3) the stiffness of the composite dynamic vibration absorber is continuously and linearly varied, i.e. ke1Being constant, the rate of change of stiffness within the damping band is:
4) the excitation frequency omega is equal to the natural frequency of the composite dynamic vibration absorber, i.e.
5) The rate of change of the mass of the vibration absorber can be found to be:
the control of the stiffness and mass of the vibration absorber takes the following control strategy:
substituting the above equations into equation (7), the control strategy is obtained as follows:
the required stiffness K of the absorber referred to above is related to the capacitance C incorporated:
wherein K is the rigidity of the piezoelectric ceramic piece, KEThe rigidity of the short circuit of the piezoelectric ceramic piece is shown, C is the total capacitance of an external circuit,
the inherent capacitance of the piezoceramic wafer is k p, which is the coupling coefficient of the piezoceramic.
2. The method according to claim 1, wherein said composite type dynamic vibration absorber comprises a main system (1), further comprising a signal acquisition unit, a control unit, and a vibration absorber whose mass and stiffness are continuously varied;
the vibration absorber with continuously changed mass and rigidity comprises a main system (1), and further comprises a variable rigidity module (2) and a variable mass module which are positioned on the main system (1), wherein the variable mass module is positioned at the upper part of the variable rigidity module (2);
the variable stiffness module comprises piezoelectric ceramics (13) and an external circuit (20) connected with the piezoelectric ceramics (13) in parallel, wherein the external circuit (20) comprises a relay (22) and a capacitor (23) connected with the relay (22) in series;
the variable mass module comprises a fixed mass unit (3) and a variable mass unit positioned on the fixed mass unit (3); the variable mass unit comprises an actuating mechanism, the actuating mechanism comprises a liquid tank (4) and a water pump (11) connected with the liquid tank (4), and the mass of the liquid entering the liquid tank (4) is controlled by the water pump (11) to realize the change of the mass of the variable mass unit; the water pump (11) is connected with the output end of the control unit;
the control unit controls the on-off of a relay (22) of the external circuit (20) according to the external excitation frequency acquired by the signal acquisition unit to change the number of capacitors incorporated in the piezoelectric ceramic (13), so that the rigidity of the vibration absorber with continuously changed mass and rigidity is changed; meanwhile, the control unit changes the mass of the mass-changing module according to the external excitation frequency acquired by the signal acquisition unit, so that the mass of the vibration absorber with continuously changed mass and rigidity is changed; the natural frequency of the vibration absorber with the continuously changed mass and rigidity is changed through the rigidity change of the rigidity changing module (2) and the mass change of the mass changing module, so that the natural frequency is synchronous with the collected external excitation frequency.
3. The method according to claim 2, characterized in that the signal acquisition unit comprises a flow sensor (12), a charge amplifier (7), a controllable power supply (5) and an acceleration sensor (9) on the variable mass module, the output of the acceleration sensor (9) being connected to the input of the charge amplifier (7); the output ends of the charge amplifier (7) and the flow sensor (12) are connected with the input end of the control unit; the output end of the control unit (6) is connected with the controllable power supply (5) and the variable mass module, the output end of the controllable power supply (5) is connected with the electronic connector (14), the charge amplifier (7) receives an acceleration signal transmitted by the acceleration sensor (9), the acceleration signal is converted into a charge signal and transmitted to the control unit, and the control unit obtains the external excitation frequency through the received charge signal.
4. The method according to claim 2, characterized in that the variable stiffness module (2) further comprises an electronic connector (14), the external circuit (20) output being connected in parallel with the piezoelectric ceramic (13), the external circuit (20) input being connected to the electronic connector (14).
5. The method according to claim 2, wherein the variable stiffness module (2) further comprises a connecting block (17), the external circuit (20) is fixed on the variable stiffness module (2) by the connecting block (17), the outer sides of the piezoelectric ceramics (13) are respectively and rigidly connected with a top cover (15) and a bottom cover (18), the top cover (15) and the bottom cover (18) are fixed by the shell (16), and the connecting block (17) is respectively arranged on the outer sides of the top cover (15) and the bottom cover (18).
6. The method according to claim 2, characterized in that the liquid tank (4) is divided into an upper air chamber (26) and a lower liquid chamber (27), the upper air chamber (26) and the lower liquid chamber (27) being separated by a piston (25), the piston (25) being mounted on a guide rod (28), the guide rod (28) being located vertically in the middle of the liquid tank (4), and an air outlet (24) being machined in the upper side of the liquid tank (4).
7. The method according to claim 2, wherein the actuator further comprises a reservoir (8), the reservoir (4) being connected to a pump (11) via a hose (10), the pump (11) being connected to the reservoir (8).
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| CN112069615B (en) * | 2020-08-19 | 2024-02-02 | 中国人民解放军92578部队 | Combined dynamic vibration absorber optimization method, system, terminal equipment and storage medium |
| CN112483586B (en) * | 2020-10-19 | 2022-04-15 | 南京航空航天大学 | Tunable dynamic vibration absorber based on intelligent spring and control method |
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