A dynamic vibration absorption system and method integrating semi-active and active control functions

Abstract

The present invention discloses a dynamic vibration absorption system and method that integrates semi-active and active control functions. The vibration absorption system includes a base, a beam, an energy-absorbing mass, a vibration sensor, a signal conditioning circuit, an A / D conversion module, a control module, a D / A conversion module, and a power amplifier. The base is fixed on the vibration suppression object; the beam includes three piezoelectric plates and two composite plates, which are staggered and stacked. During operation, the control module controls the operation of the three piezoelectric plates based on the sensing data of the vibration sensor. The present invention adopts a working mode that combines active and semi-active, which can not only achieve stiffness changes within a large range to achieve semi-active control, but also achieve active control within the full frequency range. It has a high degree of integration, strong real-time performance, a wide adjustable range, and good self-tuning performance.

Description

Technical Field

[0001] The present invention relates to the field of vibration control, and in particular to a dynamic vibration absorption system and method integrating semi-active and active control functions. Background Art

[0002] A dynamic vibration absorber is a device attached to a main structure that absorbs the vibration energy of the main structure to reduce the vibration response of the main structure. It is widely used in the fields of shipbuilding, machinery, aerospace, etc. The earliest recorded application of a dynamic vibration absorber is the Frahm vibration absorber in the early 19th century, which was used on the anti-roll water tanks of large oil tankers. Early dynamic vibration absorbers were mostly passive vibration absorbers, which have a simple structure and are easy to implement. Passive vibration absorbers have a good vibration absorption effect for main structures with a single vibration frequency. However, once a passive vibration absorber is designed and formed, it is difficult to change, its parameters cannot be adjusted, and the effective frequency band is narrow, which is not conducive to vibration suppression applications of broadband structures.

[0003] Active vibration absorbers, by applying a counteracting force to the main structure, ideally can suppress structural vibrations over a wide frequency band. However, active vibration absorbers require a continuous supply of energy and consume relatively high amounts of energy. Semi-active vibration absorbers, by autonomously adjusting their parameters to align their natural frequency with the main structure's vibration frequency, are suitable for wide-band structural vibration suppression and require significantly less energy than active vibration absorbers. Commonly used semi-active vibration absorbers achieve a natural frequency consistent with the main structure by varying stiffness or mass. These include mechanical stiffness-adjusted vibration absorbers, structurally-based piecewise linear adaptive dynamic vibration absorbers, variable internal pressure air springs, and fluid-filled variable mass dynamic vibration absorbers. However, semi-active vibration absorbers typically have a limited frequency adjustment range, making them unsuitable for wide-band dynamic vibration suppression. Combining the advantages of semi-active and active control, a dynamic vibration absorber combining both semi-active and active control features is designed, with low energy consumption and meeting wide-band vibration suppression requirements. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a dynamic vibration absorption system and method integrating semi-active and active control functions in order to address the defects involved in the background technology.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] A dynamic vibration absorption system integrating semi-active and active control functions, comprising a base, a beam, an energy-absorbing mass block, a vibration sensor, a signal conditioning circuit, an A / D conversion module, a control module, a D / A conversion module and a power amplifier;

[0007] The base is fixed on the vibration suppression object;

[0008] The beam body includes first to third piezoelectric plates and first to second composite plates, wherein the first to third piezoelectric plates are made of piezoelectric material; the first piezoelectric plate, the first composite plate, the second piezoelectric plate, the second composite plate, and the third piezoelectric plate are stacked in sequence from top to bottom, and the layers are connected by gluing;

[0009] One end of the beam is fixedly connected to the base, and the other end is fixedly connected to the energy-absorbing mass block;

[0010] The vibration sensor is fixed on the base and is used to sense the vibration signal of the vibration suppression object;

[0011] The vibration sensor, signal conditioning circuit, A / D conversion module, control module, and D / A conversion module are electrically connected in sequence, and the first to third piezoelectric plates are electrically connected to the D / A conversion module through the power amplifier; the control module is used to send corresponding control signals according to the received signals to control the operation of the first to third piezoelectric plates;

[0012] The signal conditioning circuit is used to rectify, filter and stabilize the analog signal sensed by the vibration sensor;

[0013] The A / D conversion module is used to convert the received analog signal into a digital signal;

[0014] The D / A conversion module is used to convert the received digital signal into an analog signal.

[0015] As a further optimization solution of the dynamic vibration absorption system integrating semi-active and active control functions of the present invention, it also includes a fixing bolt and a fixing nut;

[0016] The energy-absorbing mass block includes 2N energy-absorbing mass units, where N is a natural number greater than or equal to 1;

[0017] The energy-absorbing mass unit is a cylinder or a regular prism, and a through hole is provided at the center thereof to cooperate with the fixing bolt;

[0018] One end of the beam away from the base is provided with a through hole that cooperates with the fixing bolt;

[0019] The fixing bolts sequentially pass through the through holes in the centers of N of the 2N energy-absorbing mass units, the through hole on the beam body, the through holes in the centers of the other N of the 2N energy-absorbing mass units, and are then fixedly connected to the fixing nuts, thereby fixing the 2N energy-absorbing mass units and the end of the beam body away from the base together.

[0020] As a further optimization solution of the power vibration absorption system integrating semi-active and active control functions of the present invention, the first to second composite plates are both made of carbon fiber composite materials.

[0021] The present invention also discloses a vibration absorption method of the dynamic vibration absorption system integrating semi-active and active control functions, comprising the following steps:

[0022] Step 1), after receiving the vibration signal from the vibration sensor, the control module obtains the vibration response frequency ω of the vibration suppression object through fast Fourier transform;

[0023] Step 2), the control module compares the vibration response frequency ω with the preset first frequency threshold ω0 and the second frequency threshold ω1, and ω1>ω0;

[0024] Step 2.1): If ω0<ω<ω1, the vibration absorption system operates in a semi-active vibration absorption mode, and the control module simultaneously excites the first, second, and third piezoelectric plates with a preset first excitation signal A;

[0025] In step 2.2), if ω≤ω0 or ω≥ω1, the vibration absorption system operates in an active vibration absorption mode. The control module excites the first piezoelectric plate with the second excitation signal B and excites the third piezoelectric plate with the third excitation signal C. The second excitation signal B and the third excitation signal C are equal in magnitude and opposite in phase, so that the first piezoelectric plate and the third piezoelectric plate work together to form a bending moment effect on the beam, causing the beam and the energy-absorbing mass block to vibrate in the same direction as the vibration suppression object, thereby achieving the purpose of absorbing and reducing the vibration of the vibration suppression object. At this time, the second piezoelectric plate does not work.

[0026] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0027] The dynamic vibration absorber system described in this invention features a high level of integration, employing a combination of active and semi-active operating modes. This system is capable of achieving both semi-active control through varying stiffness over a wide range, and active control across the full frequency range. Regarding semi-active control, the variable stiffness approach employed is fundamentally different from conventional semi-active dynamic vibration absorbers. This system utilizes piezoelectric materials to achieve stiffness adjustment, utilizing the tensile force exerted by the piezoelectric material upon energization to achieve system stiffness variation. This system boasts a high level of integration, strong real-time performance, and a wide adjustable range. Regarding active control, it exhibits fast response and excellent self-tuning properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of the dynamic vibration absorbing device of the present invention;

[0029] Figure 2 This is a schematic diagram of a control circuit based on a single chip microcomputer of the present invention;

[0030] Figure 3 Single chip microcomputer control system circuit diagram

[0031] Figure 4It is a simplified diagram of the vibration absorption system;

[0032] Figure 5 is a flow chart of the method of the present invention.

[0033] In the figure, 1-base, 2-beam, 3-energy-absorbing mass block, 4-control module. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings:

[0035] The present invention may be implemented in different forms and should not be considered limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0036] like Figure 1 As shown, the present invention discloses a dynamic vibration absorption system integrating semi-active and active control functions, comprising a base, a beam, an energy-absorbing mass block, a vibration sensor, a signal conditioning circuit, an A / D conversion module, a control module, a D / A conversion module and a power amplifier;

[0037] The base is fixed on the vibration suppression object;

[0038] The beam body includes first to third piezoelectric plates and first to second composite plates, wherein the first to third piezoelectric plates are made of piezoelectric material; the first piezoelectric plate, the first composite plate, the second piezoelectric plate, the second composite plate, and the third piezoelectric plate are stacked in sequence from top to bottom, and the layers are connected by gluing;

[0039] One end of the beam is fixedly connected to the base, and the other end is fixedly connected to the energy-absorbing mass block;

[0040] The vibration sensor is fixed on the base and is used to sense the vibration signal of the vibration suppression object;

[0041] like Figure 2 As shown, the vibration sensor, signal conditioning circuit, A / D conversion module, control module, and D / A conversion module are electrically connected in sequence, and the first to third piezoelectric plates are electrically connected to the D / A conversion module through the power amplifier; the control module is used to send corresponding control signals according to the received signals to control the operation of the first to third piezoelectric plates;

[0042] The signal conditioning circuit is used to rectify, filter and stabilize the analog signal sensed by the vibration sensor;

[0043] The A / D conversion module is used to convert the received analog signal into a digital signal;

[0044] The D / A conversion module is used to convert the received digital signal into an analog signal.

[0045] The energy-absorbing mass block comprises 2N energy-absorbing mass units, which are fixed by fixing bolts and fixing nuts, where N is a natural number greater than or equal to 1;

[0046] The energy-absorbing mass unit is a cylinder or a regular prism, and a through hole is provided at the center thereof to cooperate with the fixing bolt;

[0047] One end of the beam away from the base is provided with a through hole that cooperates with the fixing bolt;

[0048] The fixing bolts sequentially pass through the through holes in the centers of N of the 2N energy-absorbing mass units, the through hole on the beam body, the through holes in the centers of the other N of the 2N energy-absorbing mass units, and are then fixedly connected to the fixing nuts, thereby fixing the 2N energy-absorbing mass units and the end of the beam body away from the base together.

[0049] The first and second composite plates are preferably made of carbon fiber composite materials.

[0050] The entire vibration absorption system of the present invention has a high integration feature. The control module is composed of a single-chip minimum system, and the entire peripheral circuit is integrated on a development board. Figure 3 shown.

[0051] The control module of the present invention has a self-tuning feature, and the single chip control program executes automatic adjustment functions such as port communication, signal acquisition, control algorithm implementation, and active and passive control mode switching.

[0052] The working principle of the power vibration absorbing device based on single chip microcomputer control of the present invention is as follows:

[0053] When the sensor detects the vibration data of the controlled object, the data is transmitted to the single-chip microcomputer circuit, and through a series of processing, the appropriate voltage signal is output to the power amplifier. The power amplifier outputs a high voltage to control the stretching of the piezoelectric material, thereby changing the natural frequency of the vibration absorption system. When the vibration frequency of the controlled object exceeds the natural frequency variation range of the vibration absorption system, the system changes from semi-active control to active control. The single-chip microcomputer outputs a periodic voltage signal of the corresponding frequency, which is controlled by the power amplifier to give the vibration absorption system a periodic excitation of the corresponding frequency, thereby achieving the effect of active control.

[0054] The present invention has two working modes: one is a semi-active mode, in which the control module outputs a specified voltage to control the deformation of the piezoelectric material to change the stiffness of the system, thereby achieving a semi-active vibration absorption effect; the other is an active mode. When the vibration frequency of the controlled object exceeds the natural frequency variation range of the vibration absorption system, the single-chip microcomputer outputs a corresponding voltage signal, causing the upper and lower fiber sheets of the beam body to extend or contract, providing the system with an alternating bending moment to achieve an active control effect.

[0055] The system can be simplified as Figure 4 The dual-mass-spring system shown in the figure has the following two characteristics: the upper mass, spring, and damping reflect the dynamic parameters of the vibration absorption system:

[0056] ① The stiffness k2 of the vibration absorption system can change with the size of the control voltage, and the vibration amplitude X1 of the controlled structure can be suppressed by adjusting the stiffness.

[0057] ② The vibration absorption system can exert force on the controlled structure by changing the driving voltage to achieve active control and achieve the purpose of suppressing the vibration amplitude X1 of the controlled structure.

[0058] When the system is in semi-active control mode, the response of the controlled object under external excitation F ω is the excitation frequency, considering a system with small damping or no damping, ignoring the influence of damping c2, when When the system is in active control mode, the response amplitude X1 of the controlled object under the external excitation F is close to zero, so as to achieve the effect of vibration absorption. where f c The control force generated by the piezoelectric module of the vibration absorption system. This system absorbs energy by generating a control force opposite to the excitation force, thereby reducing the response of the controlled object m1. In an ideal state, when Ff c =0, the response value of the controlled object is zero, which plays a vibration absorbing role.

[0059] like Figure 5 As shown, the present invention discloses a vibration absorption method of a dynamic vibration absorption system integrating semi-active and active control functions, comprising the following steps:

[0060] Step 1), after receiving the vibration signal from the vibration sensor, the control module obtains the vibration response frequency ω of the vibration suppression object through fast Fourier transform;

[0061] Step 2), the control module compares the vibration response frequency ω with the preset first frequency threshold ω0 and the second frequency threshold ω1, and ω1>ω0;

[0062] Step 2.1): If ω0<ω<ω1, the vibration absorption system operates in a semi-active vibration absorption mode, and the control module simultaneously excites the first, second, and third piezoelectric plates with a preset first excitation signal A;

[0063] In step 2.2), if ω≤ω0 or ω≥ω1, the vibration absorption system operates in an active vibration absorption mode. The control module excites the first piezoelectric plate with the second excitation signal B and excites the third piezoelectric plate with the third excitation signal C. The second excitation signal B and the third excitation signal C are equal in magnitude and opposite in phase, so that the first piezoelectric plate and the third piezoelectric plate work together to form a bending moment effect on the beam, causing the beam and the energy-absorbing mass block to vibrate in the same direction as the vibration suppression object, thereby achieving the purpose of absorbing and reducing the vibration of the vibration suppression object. At this time, the second piezoelectric plate does not work.

[0064] The system of the present invention has high integration, good self-tuning performance and great practical value; the adjustment frequency range is wide, and semi-active combined with active can be applied to a variety of controlled objects; and the core of the vibration absorption system is piezoelectric material, which has strong real-time performance and high controllable accuracy.

[0065] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and, unless defined as such, will not be interpreted in an idealized or overly formal sense.

[0066] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dynamic vibration absorption system integrating semi-active and active control functions, characterized in that: It includes a base, a beam, an energy-absorbing mass block, a vibration sensor, a signal conditioning circuit, an A / D conversion module, a control module, a D / A conversion module and a power amplifier; The base is fixed on the vibration suppression object; The beam body includes first to third piezoelectric plates and first to second composite plates, wherein the first to third piezoelectric plates are made of piezoelectric material; the first piezoelectric plate, the first composite plate, the second piezoelectric plate, the second composite plate, and the third piezoelectric plate are stacked in sequence from top to bottom, and the layers are connected by gluing; One end of the beam is fixedly connected to the base, and the other end is fixedly connected to the energy-absorbing mass block; The vibration sensor is fixed on the base and is used to sense the vibration signal of the vibration suppression object; The vibration sensor, signal conditioning circuit, A / D conversion module, control module, and D / A conversion module are electrically connected in sequence, and the first to third piezoelectric plates are electrically connected to the D / A conversion module through the power amplifier; the control module is used to send corresponding control signals according to the received signals to control the operation of the first to third piezoelectric plates; The signal conditioning circuit is used to rectify, filter and stabilize the analog signal sensed by the vibration sensor; The A / D conversion module is used to convert the received analog signal into a digital signal; The D / A conversion module is used to convert the received digital signal into an analog signal.

2. The dynamic vibration absorption system integrating semi-active and active control functions according to claim 1 is characterized in that: Also includes fixing bolts and nuts; The energy-absorbing mass block includes 2N energy-absorbing mass units, where N is a natural number greater than or equal to 1; The energy-absorbing mass unit is a cylinder or a regular prism, and a through hole is provided at the center thereof to cooperate with the fixing bolt; One end of the beam away from the base is provided with a through hole that cooperates with the fixing bolt; The fixing bolts sequentially pass through the through holes in the centers of N of the 2N energy-absorbing mass units, the through hole on the beam body, the through holes in the centers of the other N of the 2N energy-absorbing mass units, and are then fixedly connected to the fixing nuts, thereby fixing the 2N energy-absorbing mass units and the end of the beam body away from the base together.

3. The dynamic vibration absorption system integrating semi-active and active control functions according to claim 1 is characterized in that: The first and second composite plates are both made of carbon fiber composite materials.

4. The vibration absorption method of the dynamic vibration absorption system integrating semi-active and active control functions according to claim 1 is characterized in that: The following steps are involved: Step 1), after receiving the vibration signal from the vibration sensor, the control module obtains the vibration response frequency ω of the vibration suppression object through fast Fourier transform; Step 2), the control module compares the vibration response frequency ω with the preset first frequency threshold ω0 and the second frequency threshold ω1, and ω1>ω0; step 2.1) If ω0<ω<ω1, the vibration absorption system operates in a semi-active vibration absorption mode, and the control module simultaneously excites the first, second, and third piezoelectric plates with a preset first excitation signal A; In step 2.2), if ω≤ω0 or ω≥ω1, the vibration absorption system operates in an active vibration absorption mode. The control module excites the first piezoelectric plate with the second excitation signal B and excites the third piezoelectric plate with the third excitation signal C. The second excitation signal B and the third excitation signal C are equal in magnitude and opposite in phase, so that the first piezoelectric plate and the third piezoelectric plate work together to form a bending moment effect on the beam, causing the beam and the energy-absorbing mass block to vibrate in the same direction as the vibration suppression object, thereby achieving the purpose of absorbing and reducing the vibration of the vibration suppression object. At this time, the second piezoelectric plate does not work.

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