A passive-active composite damping system

Abstract

The application discloses a kind of active and passive composite damping systems, specifically relates to damping equipment technical field, including bottom shell, load platform, passive damping device and active damping device, passive damping device and active damping device are set between bottom shell and load platform;Passive damping device includes and is connected in parallel positive stiffness mechanism and negative stiffness mechanism;Active damping device includes controller, sensor, piezoelectric actuator and flat coil motor, sensor is fixed on load platform, sensor, piezoelectric actuator and flat coil motor are all with controller signal connection, controller processes the signal transmission of sensor, and sends command to piezoelectric actuator and flat coil motor.The application has higher control precision, stronger anti-interference ability, more excellent adaptability and flexibility, effectively reduces the inherent frequency and resonance peak peak value of damping device, and guarantees the high attenuation of high frequency vibration, realizes the vibration attenuation of wide frequency band.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction equipment technology, and in particular to a combined active and passive vibration reduction system. Background Technology

[0002] Currently, ship propulsion equipment is developing towards higher power and higher speed, which has led to more prominent vibration problems in ship equipment. It also poses new challenges to the ship's stealth performance, shock resistance, and the protection of shipborne sensitive equipment.

[0003] Vibration reduction systems in the field of ship vibration reduction employ a combination of active and passive methods to achieve better vibration reduction effects, thereby improving their disturbance resistance and service life. Current mainstream vibration reduction solutions typically use combinations such as voice coil motors with helical springs, piezoelectric ceramics with bending springs, and Lorentz motors with parallel positive and negative stiffness mechanisms. However, each of these combinations has inherent drawbacks, limiting their application effectiveness in specific situations. For example, the combination of a voice coil motor and a helical spring may exhibit dynamic response delays under rapid response requirements, thus affecting the vibration reduction effect; while the combination of piezoelectric ceramics and bending springs can provide high-frequency fast response characteristics, its stroke is short, and piezoelectric ceramics are prone to breakage under impact or overload, making it difficult to apply in high-load or high-impact environments; in the combination of a Lorentz motor and a parallel positive and negative stiffness mechanism, the Lorentz motor involves multiple mechanical and electromagnetic components, resulting in a complex structure and difficult debugging. Under specific operating conditions, the Lorentz motor may face problems such as electromagnetic interference and overheating, and due to its nonlinear characteristics, its vibration reduction effect is difficult to predict, thus increasing the difficulty of control and adjustment in practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide an active-passive composite vibration reduction system to solve the problems existing in the prior art. It has higher control precision, stronger anti-interference ability, better adaptability and flexibility, effectively reduces the natural frequency and resonance peak value of the vibration reduction device, and ensures high attenuation of high frequency vibration, thereby achieving wide-band vibration attenuation.

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

[0006] This invention provides a combined active and passive vibration reduction system, including a base shell, a load platform, a passive vibration reduction device, and an active vibration reduction device, wherein the passive vibration reduction device and the active vibration reduction device are both disposed between the base shell and the load platform;

[0007] The passive vibration damping device includes a positive stiffness mechanism and a negative stiffness mechanism arranged in parallel;

[0008] The active damping device comprises a controller, a sensor, a piezoelectric actuator and a planar voice coil motor, the sensor is fixed on the load platform, the sensor, the piezoelectric actuator and the planar voice coil motor are signal connected with the controller, the controller processes the signal transmitted by the sensor and delivers the command to the piezoelectric actuator and the planar voice coil motor.

[0009] Preferably, the positive stiffness mechanism comprises a plurality of transverse slot springs, the plurality of transverse slot springs are uniformly distributed between the bottom shell and the load platform, one end of the transverse slot spring is connected with the load platform, and the other end is fixedly connected with the bottom surface of the bottom shell.

[0010] Preferably, the negative stiffness mechanism comprises four negative stiffness units, one of the negative stiffness units is connected to each of the four corners of the bottom shell, the negative stiffness unit comprises a fixed plate, a sliding rail, a sliding block, a spring and a connecting rod, the fixed plate is fixedly connected with the side wall of the bottom shell, the sliding rail is fixedly connected with the fixed plate perpendicularly, the sliding block is slidingly connected with the sliding rail, one end of the spring is fixedly connected with the sliding block, and the other end is fixedly connected with the fixed plate, one end of the connecting rod is hingedly connected with the end of the sliding block away from the spring, and the other end is hingedly connected with the connecting column of the load platform, the two negative stiffness units arranged on the opposite side walls of the bottom shell are symmetrical about the connecting column.

[0011] Preferably, the negative stiffness unit further comprises a limiting pad, the end of the sliding block close to the fixed plate is fixedly connected with the limiting pad, the end of the fixed plate close to the sliding block is fixedly connected with the limiting pad, and the spring is sleeved outside the limiting pad.

[0012] Preferably, the number of piezoelectric actuators is the same as the number of transverse slot springs, the piezoelectric actuator comprises a piezoelectric actuator body and a base, the piezoelectric actuator body is fixedly connected with the base, the base is fixedly installed at the end of the transverse slot spring away from the bottom shell, and the piezoelectric actuator body is fixedly connected with the bottom surface of the load platform.

[0013] Preferably, the planar voice coil motor comprises a stator, a mover and an output shaft, the stator is fixedly connected to the bottom surface of the bottom shell, the mover is slidingly connected with the stator, the mover can move in the vertical direction after the stator is electrified, one end of the output shaft is fixedly connected with the mover, and the other end is fixedly connected with the bottom surface of the load platform.

[0014] Preferably, the number of planar voice coil motors is a plurality, and the plurality of planar voice coil motors are fixedly connected side by side.

[0015] Preferably, the buffer device is further arranged between the bottom shell and the load platform.

[0016] Preferably, the buffer device comprises a plurality of hydraulic buffers, the plurality of hydraulic buffers are uniformly distributed between the bottom shell and the load platform, and the hydraulic buffers are fixedly connected with the bottom surface of the bottom shell.

[0017] Preferably, the side wall of the bottom shell is provided with an observation window.

[0018] The present application has the following technical effects relative to the prior art:

[0019] The present application provides a kind of active and passive composite damping system, passive damping device being arranged between bottom shell and load platform includes parallelly connected positive stiffness mechanism and negative stiffness mechanism, positive stiffness mechanism has the function of high stiffness and large carrying capacity, negative stiffness mechanism can reduce the dynamic stiffness of damping device, positive stiffness mechanism and negative stiffness mechanism are parallelly connected to make system have the characteristics of high static stiffness and low dynamic stiffness, can realize damping device with large carrying capacity while ensuring lower natural frequency, realize the effect of high static stiffness and low dynamic stiffness, reduce system natural frequency and widen damping bandwidth;Active damping device uses flat panel voice coil motor and piezoelectric actuator parallelly connected as double actuator to provide double active control force, realizes dynamic adjustment by controller, reduces damping device resonance peak value, ensures high attenuation of high frequency vibration, realizes wideband vibration attenuation, and compared with traditional single active actuator, with higher control precision, stronger anti-interference ability, more excellent adaptability and flexibility, and improved dynamic response characteristics and comprehensive damping effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0021] Figure 1 It is a structural schematic diagram of active and passive composite damping system;

[0022] Figure 2 It is a structural schematic diagram of active and passive composite damping system (remove load platform);

[0023] Figure 3 It is a schematic diagram of negative stiffness mechanism 4 and load platform connection;

[0024] Figure 4 It is a schematic diagram of piezoelectric actuator, transverse slot spring and load platform connection;

[0025] Figure 5This is a schematic diagram of the piezoelectric actuator and the transverse slot spring.

[0026] Figure 6 This is a schematic diagram of a flat-plate voice coil motor.

[0027] Figure 7 This is a schematic diagram of the buffer device.

[0028] Figure 8 This is a schematic diagram of the bottom shell structure;

[0029] Figure 9 This is a schematic diagram of the principle of a traditional passive vibration reduction system;

[0030] Figure 10 This is a schematic diagram of the active-passive composite vibration reduction system of the present invention;

[0031] Figure 11 The graph shows a comparison of the transmissivity curves of traditional passive vibration reduction, the passive vibration reduction of this invention, and the active-passive composite vibration reduction system of this invention.

[0032] In the diagram: 1. Load platform; 101. Limiting boss; 102. Connecting column; 2. Bottom shell; 201. Observation window; 202. Limiting column; 203. Connecting boss; 3. Positive stiffness mechanism; 301. Horizontal groove spring; 4. Negative stiffness mechanism; 401. Spring; 402. Slide rail; 403. Slider; 404. Connecting rod; 405. Limiting pad; 5. Hydraulic buffer; 501. Rubber head; 502. Piston rod; 503. Adjusting nut; 6. Flat voice coil motor; 601. Mover; 602. Stator; 603. Output shaft; 7. Piezoelectric actuator; 701. Piezoelectric actuator body; 702. Base. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The purpose of this invention is to provide an active-passive composite vibration reduction system to solve the problems existing in the prior art. It has higher control precision, stronger anti-interference ability, better adaptability and flexibility, effectively reduces the natural frequency and resonance peak value of the vibration reduction device, and ensures high attenuation of high frequency vibration, thereby achieving wide-band vibration attenuation.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] The application provides a kind of active and passive composite damping system, such as Figures 1-2 As shown, including bottom shell 2, load platform 1, passive damping device and active damping device, passive damping device and active damping device are arranged between bottom shell 2 and load platform 1;Passive damping device includes positive stiffness mechanism 3 and negative stiffness mechanism 4 arranged in parallel;Active damping device includes controller, sensor, piezoelectric actuator 7 and flat coil motor 6, sensor is fixed on load platform 1, sensor, piezoelectric actuator 7 and flat coil motor 6 are all connected with controller signal, controller processes the signal transmitted by sensor, and sends command to piezoelectric actuator 7 and flat coil motor 6.Passive damping device arranged between bottom shell 2 and load platform 1 includes positive stiffness mechanism 3 and negative stiffness mechanism 4 arranged in parallel;Positive stiffness mechanism 3 has the function of high stiffness and large bearing capacity, negative stiffness mechanism 4 can reduce the dynamic stiffness of damping device, positive stiffness mechanism 3 and negative stiffness mechanism 4 are connected in parallel, so that the system has the characteristics of high static stiffness and low dynamic stiffness, which can realize low natural frequency while ensuring large bearing capacity, realize the effect of high static stiffness and low dynamic stiffness, reduce the natural frequency of system and widen the damping bandwidth;Active damping device uses flat coil motor 6 and piezoelectric actuator 7 as double actuator to provide double active control force, realizes dynamic adjustment through controller, piezoelectric actuator 7 and flat coil motor 6 as double actuator can analyze the data transmitted by sensor by using PID control, fuzzy control or adaptive control and other algorithms of controller, and calculate the active control force needed, realize dynamic adjustment of vibration, reduce the peak value of system resonance, ensure high attenuation of high frequency vibration, realize wideband vibration attenuation, and compared with traditional single active actuator, piezoelectric actuator 7 and flat coil motor 6 as double actuator can work at different phases, and by adjusting the phase difference between the two actuators, the vibration of specific frequency can be targetedly suppressed, which has higher control precision, stronger anti-interference ability, better adaptability and flexibility, improved dynamic response characteristics and comprehensive damping effect.By dispersing load to two actuators, the pressure required to be borne by single actuator is reduced, in the case of single actuator failure, the other actuator can still work, ensure that the basic function of system is not affected, improve the stability and reliability of system and fault tolerance ability;And for some nonlinear systems, double actuator can realize nonlinear control strategy, and through nonlinear adjustment of acting force, the damping effect of system is improved.

[0037] The piezoelectric actuator 7 has fast high-frequency response characteristics and precise control effect, the fast high-frequency response characteristics can realize fast response and control to excitation, and then quickly adjust the active damping force, and the micron-level or even nanometer-level displacement adjustment can provide high-precision displacement control, but one of the shortcomings of the piezoelectric actuator 7 is short stroke, which is difficult to apply in large amplitude vibration problems; compared with the piezoelectric ceramic, the flat plate type voice coil motor 6 has the characteristics of large stroke and can realize large amplitude vibration compensation, but the response frequency is low; therefore, the flat plate type voice coil motor 6 and the piezoelectric actuator 7 are connected in parallel, which can compensate each other, solve the problems of short stroke of the piezoelectric actuator 7 and low response frequency of the flat plate type voice coil motor 6, and thus ensure that high-precision active damping can be ensured under the condition of guaranteeing effective control of large range vibration amplitude.

[0038] It is further preferred in the embodiments of the present application that the positive stiffness mechanism 3 comprises a plurality of transverse slot springs 301, the plurality of transverse slot springs 301 are uniformly distributed between the bottom shell 2 and the load platform 1, one end of the transverse slot spring 301 is connected with the load platform 1, and the other end is fixedly connected with the bottom surface of the bottom shell 2. The transverse slot spring 301 can effectively absorb and attenuate the impact and vibration from the external environment, improve the dynamic performance of the damping device; at the same time, has high axial stiffness and large carrying capacity, good wear resistance and fatigue resistance, and long service life; and the stiffness of the transverse slot spring 301 can be flexibly adjusted by changing the size, shape and material properties of the transverse slot, so as to meet the damping requirements of different environments and realize the adjustability of stiffness.

[0039] It is further preferred in the embodiments of the present application that, as shown in Figure 3 The negative stiffness mechanism 4 comprises four negative stiffness units, one negative stiffness unit is connected to each corner of the bottom shell 2, the negative stiffness unit comprises a fixed plate, a sliding rail 402, a sliding block 403, a spring 401 and a connecting rod 404, the fixed plate is fixedly connected with the side wall of the bottom shell 2, the sliding rail 402 is fixedly connected with the fixed plate perpendicularly, the sliding block 403 is slidingly connected with the sliding rail 402, one end of the spring 401 is fixedly connected with the sliding block 403, and the other end is fixedly connected with the fixed plate, one end of the connecting rod 404 is hingedly connected with the end of the sliding block 403 away from the spring 401, and the other end is hingedly connected with the connecting column 102 of the load platform 1, and the two negative stiffness units arranged on the opposite side walls of the bottom shell 2 are symmetrical about the connecting column 102; the negative stiffness unit further comprises a limiting pad 405, the end of the sliding block 403 close to the fixed plate is fixedly connected with the limiting pad 405, the end of the fixed plate close to the sliding block 403 is fixedly connected with the limiting pad 405, and the spring 401 is sleeved outside the limiting pad 405. The negative stiffness mechanism 4 provides negative stiffness and elastic restoring force by the rotational connection of the connecting rod 404 and the sliding block 403 and the compression of the spring 401 by the sliding of the sliding block 403 on the sliding rail 402; at the same time, the limiting pad 405 can prevent the spring 401 from failing under overload; the compensation of negative stiffness makes the overall stiffness of the system decrease, which is beneficial to the reduction of the natural frequency.

[0040] Further preferred in the embodiments of the present application is that, as shown in Figures 4-5 The piezoelectric actuator 7 includes a piezoelectric actuator body 701 and a base 702, the piezoelectric actuator body 701 is fixedly connected with the base 702, the base 702 is fixedly installed at one end of the transverse slot spring 301 away from the bottom shell 2, and the piezoelectric actuator body 701 is fixedly connected with the bottom surface of the load platform 1. The piezoelectric actuator body 701 is fixedly connected with the limiting boss 101 of the bottom surface of the load platform 1, the base 702 of the piezoelectric actuator 7 is positioned by bolt and top connection of the transverse slot spring 301, the series connection of the piezoelectric actuator 7 and the transverse slot spring 301 can be realized, axial positioning can be realized, and axial transmission of elastic restoring force can be ensured.

[0041] Further preferred in the embodiments of the present application is that, as shown in Figure 6 The plate type voice coil motor 6 includes a stator 602, a mover 601 and an output shaft 603, the stator 602 is fixedly connected with the bottom surface of the bottom shell 2, the mover 601 is slidingly connected with the stator 602, the mover 601 can move in the vertical direction when the stator 602 is energized, one end of the output shaft 603 is fixedly connected with the mover 601, and the other end is fixedly connected with the bottom surface of the load platform 1. The plate type voice coil motor 6 reaches the load platform 1 to realize vibration reduction after axial transmission of the driving force generated by the plate type voice coil motor 6. In addition to the advantages of the traditional voice coil motor, the plate type voice coil motor 6 also has the characteristics of large contact area, fast heat dissipation, lightweight structure and long service life. The number of the plate type voice coil motor 6 is multiple, and the multiple plate type voice coil motors 6 are fixedly connected side by side. The arrangement mode of the multiple plate type voice coil motors 6 side by side can further improve the vibration isolation performance, ensure compact structure and save space while increasing the active control force.

[0042] Further preferred in the embodiments of the present application is that, as shown in Figure 7As shown, the active-passive composite damping system further comprises a buffer device, which is arranged between the bottom shell 2 and the load platform 1, and comprises a plurality of hydraulic buffers 5 uniformly distributed between the bottom shell 2 and the load platform 1, and the hydraulic buffers 5 are fixedly connected with the bottom surface of the bottom shell 2. Further preferably, the free end of the piston rod 502 of the hydraulic buffer 5 is sleeved with a rubber head 501, which can absorb vibration and impact; the oil of the hydraulic buffer 5 has a certain viscosity, and when the top of the hydraulic buffer 5 is impacted or vibrated, the impact force can be absorbed through the flow of the oil, and the impact force is converted into oil pressure for uniform dispersion, thereby providing the effect of damping and inhibiting resonance and reducing impact; the bottom of the hydraulic buffer 5 is also provided with an adjusting nut 503, and the height of the hydraulic buffer 5 can be changed by rotating the adjusting nut 503, so as to adjust the impact on the top of the hydraulic buffer 5 to adapt to different loads, and ensure that the internal mechanism of the system will not be crushed under overload while increasing the carrying capacity.

[0043] Further preferably in the embodiments of the present application, as Figure 8 As shown, the side wall of the bottom shell 2 is provided with an observation window 201, which facilitates timely observation of the running condition of the internal structure of the damping device; the bottom surface of the bottom shell 2 is provided with a hollow limiting column 202 for fixed connection with the hydraulic buffer 5, which can reduce the weight of the damping device, and the hollow limiting column 202 has a thread inside, which facilitates threaded connection with the hydraulic buffer 5. The bottom surface of the bottom shell 2 is also provided with a connecting boss 203 for fixed connection with the transverse groove spring 301, which can position and fix the bottom of the transverse groove spring 301.

[0044] As Figure 9 shown, wherein the mass of the load platform is M, the stiffness of the damping system is k, and the damping of the system is c. The differential equation of the damping platform under passive control is:

[0045]

[0046] The transfer function corresponding to passive damping is:

[0047]

[0048] In the formula, x0 is the vibration displacement of the load platform, x i is the vibration displacement of the foundation platform, s=jω is the complex variable of Laplace transform, ω is the frequency domain coefficient, c is the equivalent damping of the mechanism, k is the equivalent stiffness between the load platform and the foundation platform, and M is the mass of the load platform.

[0049] Figure 10 and Figure 9In comparison, the system has two active actuators, and a feedback sensor is attached to the load platform side to obtain feedback signals and transmit them to the controller, which generates control signals to the actuators to generate forces F1 and F2 to counteract the vibration. The differential equation of the vibration reduction platform under feedback control is:

[0050]

[0051] The transfer function of the system under integral force feedback control algorithm is:

[0052]

[0053] In the formula, c is the equivalent damping of the vibration reduction system, k is the equivalent stiffness of the vibration isolation system, and M is the mass of the load platform. When the integral gain coefficient k i is much larger than the equivalent damping c, the equivalent damping of the system can be ignored.

[0054] As Figure 11 shown, the design of the active and passive composite vibration reduction system of the present application makes the stiffness of the system decrease, the natural frequency move forward, and the resonance peak at low frequency is reduced while the high frequency still maintains a high attenuation rate.

[0055] The principles and implementation modes of the present application are described by applying specific examples in the present application. The above examples are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. An active-passive hybrid vibration reduction system, characterized by: The device comprises a bottom shell, a load platform, a passive damping device and an active damping device, the passive damping device and the active damping device are arranged between the bottom shell and the load platform; The passive damping device comprises a positive stiffness mechanism and a negative stiffness mechanism arranged in parallel; The active damping device comprises a controller, a sensor, a piezoelectric actuator and a planar voice coil motor, the sensor is fixed on the load platform, the piezoelectric actuator and the planar voice coil motor are connected in parallel as a double actuator, the sensor, the piezoelectric actuator and the planar voice coil motor are signal connected with the controller, the controller processes the signal transmitted by the sensor and sends a command to the piezoelectric actuator and the planar voice coil motor connected in parallel as a double actuator, and the phase difference between the piezoelectric actuator and the planar voice coil motor can be adjusted to specifically suppress vibration of a specific frequency.

2. The passive and active compound damping system of claim 1, wherein: The positive stiffness mechanism comprises a plurality of transverse groove springs, the plurality of transverse groove springs are uniformly distributed between the bottom shell and the load platform, one end of the transverse groove spring is connected with the load platform, and the other end is fixedly connected with the bottom surface of the bottom shell.

3. The passive and active compound damping system of claim 1, wherein: The negative stiffness mechanism comprises four negative stiffness units, one negative stiffness unit is connected to each corner of the bottom shell, the negative stiffness unit comprises a fixed plate, a sliding rail, a sliding block, a spring and a connecting rod, the fixed plate is fixedly connected with the side wall of the bottom shell, the sliding rail is fixedly connected with the fixed plate perpendicularly, the sliding block is slidingly connected with the sliding rail, one end of the spring is fixedly connected with the sliding block, and the other end is fixedly connected with the fixed plate, one end of the connecting rod is hingedly connected with the end of the sliding block away from the spring, and the other end is hingedly connected with the connecting column of the load platform, and the two negative stiffness units arranged on the opposite side walls of the bottom shell are symmetrical about the connecting column.

4. The passive and active compound damping system of claim 3, wherein: The negative stiffness unit further comprises a limiting pad, the end of the sliding block close to the fixed plate is fixedly connected with the limiting pad, the end of the fixed plate close to the sliding block is fixedly connected with the limiting pad, and the spring is sleeved outside the limiting pad.

5. The passive and active compound damping system of claim 2, wherein: The number of piezoelectric actuators is the same as the number of transverse groove springs, the piezoelectric actuator comprises a piezoelectric actuator body and a base, the piezoelectric actuator body is fixedly connected with the base, the base is fixedly installed at the end of the transverse groove spring away from the bottom shell, and the piezoelectric actuator body is fixedly connected with the bottom surface of the load platform.

6. The passive and active compound damping system of claim 1, wherein: The planar voice coil motor comprises a stator, a mover and an output shaft, the stator is fixedly connected to the bottom surface of the bottom shell, the mover is slidingly connected with the stator, the mover can move in the vertical direction when the stator is energized, one end of the output shaft is fixedly connected with the mover, and the other end is fixedly connected with the bottom surface of the load platform.

7. The passive and active compound damping system of claim 6, wherein: The number of planar voice coil motors is multiple, and multiple planar voice coil motors are fixedly connected side by side.

8. The passive and active compound damping system of claim 1, wherein: It further comprises a buffer device, and the buffer device is arranged between the bottom shell and the load platform.

9. The passive and active compound damping system of claim 8, wherein: The buffer device comprises a plurality of hydraulic buffers, which are uniformly distributed between the bottom shell and the load platform and fixedly connected with the bottom surface of the bottom shell.

10. The passive and active compound damping system of claim 1, wherein: The sidewall of the bottom shell is provided with an observation window.

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