CN107939900A - Wideband isolation mounting and vibration isolation control method - Google Patents

Abstract

The invention discloses a broadband vibration isolation device, which includes a magneto-rheological damper, which is used to generate damping force for semi-active vibration isolation when the equipment connected to the vibration isolation device is in a low-frequency and large-amplitude vibration region; a piezoelectric element , connected with the magneto-rheological damper, used to generate driving force for active vibration isolation when the equipment connected to the vibration isolation device is in the high-frequency and small-amplitude vibration region, and used to control the equipment connected to the vibration isolation device The vibration signal is detected; and the controller is used to receive the vibration signal detected by the piezoelectric element, and control the magnetorheological damper to generate a semi-active vibration isolation damping force or control the piezoelectric element to generate an active vibration isolation driving force according to the vibration signal The present invention can select a semi-active or active vibration isolation method according to the current state of the vibration-isolated equipment, effectively improve the overall vibration isolation effect and control accuracy, reduce the complexity of control, and meet the requirements of high-precision equipment vibration isolation.

Description

Broadband vibration isolation device and vibration isolation control method

technical field

The invention relates to equipment vibration isolation technology, in particular to a broadband vibration isolation device and a vibration isolation control method.

Background technique

Structural vibration control is one of the high-tech fields of current structural engineering. According to whether external energy is needed, structural control can be divided into four categories: passive control, active control, semi-active control and hybrid control; passive control is also called passive control. External input energy is required, while the process of active control depends on external excitation and structural response information, and requires external input energy to provide control force. Semi-active control also uses structural response or external excitation information, but only requires a small amount of energy to change Control the system shape to achieve the purpose of changing the dynamic characteristics of the structure to reduce the response; hybrid control refers to the mixed application of the above three types of control, applying active and passive control to the structure at the same time, and analyzing its response as a whole, which overcomes the application of pure passive control The limitation also reduces the control force, thereby reducing the power, submission, energy and maintenance costs of external control equipment, and increasing the reliability of the system.

With the continuous development of current science and technology, various precision equipment and high-tech products emerge in an endless stream. Precision equipment and some weapons and equipment are subject to complex excitations. The frequency band of these excitations is wide, and traditional passive vibration isolation devices are difficult to meet the requirements. The effect obtained is also relatively limited. Although the effect of active control is better, the structure is complicated and the energy consumption is relatively large.

Contents of the invention

In view of this, the object of the present invention is to provide a broadband vibration isolation device and vibration isolation control method, which can select a semi-active or active vibration isolation mode according to the current state of the vibration-isolated equipment, and effectively improve the overall vibration isolation effect and control accuracy , reduce the complexity of control, and meet the requirements of vibration isolation for high-precision equipment.

The broadband vibration isolation device of the present invention comprises:

Magneto-rheological dampers are used to generate damping force for semi-active vibration isolation when the equipment connected to the vibration isolation device is in the low-frequency and large-amplitude vibration region;

The piezoelectric element, connected with the magneto-rheological damper, is used to generate driving force for active vibration isolation when the equipment connected to the vibration isolation device is in the high-frequency and small-amplitude vibration region, and is used to control the vibration isolation device. Vibration signals from connected devices are detected; and

The controller is used to receive the vibration signal detected by the piezoelectric element, and control the magneto-rheological damper to generate a semi-active vibration-isolation damping force or control the piezoelectric element to generate an active vibration-isolation driving force according to the vibration signal.

Further, the piezoelectric element is connected in series with the magneto-rheological damper.

Further, the magneto-rheological damper includes a cylinder and a piston disposed in the cylinder, and the gap between the side wall of the piston and the inner wall of the cylinder is filled with magneto-rheological fluid.

Further, the magnetorheological body is magnetorheological foam.

Further, the magnetic field used to generate and control the magneto-rheological body is a composite magnetic structure composed of permanent magnets and electromagnetic coils.

Further, the permanent magnet is an annular permanent magnet, and the middle part of the piston is sequentially provided with a first annular groove for installing the annular permanent magnet and a second annular groove for installing the electromagnetic coil from inside to outside along the radial direction.

The present invention also discloses a vibration isolation control method using the broadband vibration isolation device, comprising the following steps:

A. Detect the vibration signal, and judge whether it is the vibration frequency and amplitude that need vibration isolation, if yes, go to the next step;;

B. Judging whether the vibration is in the high-frequency vibration and low-amplitude area, if so, go to the next step;;

C. Judge the high-frequency vibration frequency and perform high-frequency active vibration isolation according to the vibration frequency, and return to step B after vibration isolation;

D. In step B, if no, in the low-frequency vibration area, determine the low-frequency vibration frequency, perform low-frequency semi-active vibration isolation according to the low-frequency vibration frequency, and return to step B after vibration isolation.

Further, in step B, when the frequency ratio is less than , it is the low-frequency vibration region; when the frequency ratio is greater than or equal to , it is a high-frequency vibration region.

Beneficial effects of the present invention:

In the broadband vibration isolation device and vibration isolation control method of the present invention, when the equipment connected to the vibration isolation device vibrates, the piezoelectric element detects the vibration signal, and transmits the vibration signal to the controller, and the controller controls the equipment according to the vibration signal. When the equipment is in the low-frequency and large-amplitude vibration area, it enters the semi-active vibration isolation control mode. At this time, the magnetorheological damper starts, the piezoelectric element locks itself, and the magnetorheological damper generates vibration isolation according to the vibration frequency. The required damping force; when the equipment is in the high-frequency and small-amplitude vibration area, it enters the active vibration isolation control mode. At this time, the piezoelectric element starts, the magnetorheological damper locks itself, and the piezoelectric element generates the required vibration isolation according to the vibration frequency. driving force; therefore, the present invention can select a semi-active or active vibration isolation mode according to the current state of the vibration-isolated device, effectively improving the overall vibration isolation effect and control accuracy; in addition, the present invention utilizes the deformation of the piezoelectric element It has a corresponding proportional relationship with the applied voltage. On the one hand, the deformation of the piezoelectric element can be controlled by controlling the applied voltage value. It can be used as an active control element in the vibration isolation device to achieve active control of vibration. The deformation of the electric element under the action of external force is determined by the corresponding induced voltage value to determine the force value of the piezoelectric element. It is used as a self-sensing element in the vibration isolation device, and real-time monitoring and feedback are applied to this The mechanical characteristics of the external load and vibration of the device have realized the integration of semi-active vibration isolation control, active vibration isolation control and self-sensing in structure and function, and realized the intelligent vibration isolation control of the device in the full frequency range and the vibration reduction response of the mechanism. Real-time monitoring reduces the complexity of control and meets the requirements of vibration isolation for high-precision equipment.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

Fig. 1 is the structural representation of broadband vibration isolation device of the present invention;

Fig. 2 is the working flow chart of broadband vibration isolation device of the present invention;

Fig. 3 is the amplitude-frequency response curve of the single-degree-of-freedom forced vibration system with different damping coefficients ξ.

Detailed ways

As shown in Figures 1 to 3, the broadband vibration isolation device of this embodiment includes a magnetorheological damper, a piezoelectric element 1 and a controller: the magnetorheological damper is used when the equipment connected to the vibration isolation device is at a low frequency Damping force is generated in the large-amplitude vibration area for semi-active vibration isolation; the piezoelectric element 1 is connected with the magneto-rheological damper, which is used to generate drive when the equipment connected to the vibration isolation device is in the high-frequency and small-amplitude vibration area force for active vibration isolation, and is used to detect the vibration signal of the equipment connected to the vibration isolation device; the controller is used to receive the vibration signal detected by the piezoelectric element 1, and control the magneto-rheological damper to generate vibration according to the vibration signal. Damping force or controlling the piezoelectric element 1 to generate driving force; this device is equipped with several power sources; in Figure 1, the circuit at V1 represents the application of voltage to the piezoelectric element 1, and the expansion and contraction deformation of the piezoelectric element 1 can be adjusted by controlling the applied voltage value The amount indicated by the arrow at S2 is the linear motion direction of the piezoelectric element 1; the circuit at V2 indicates that the current is applied to the electromagnetic coil in the magnetorheological damper, and the output damping force of the magnetorheological damper can be adjusted by controlling the applied current value , the arrow at S1 is the linear motion direction of the piston rod of the magnetorheological damper; the circuit at V3 indicates the measurement of the induced voltage of the piezoelectric element 1, and the effect of the piezoelectric element 1 can be obtained by measuring the induced voltage force value; the controller can be an existing single-chip microcomputer with functions of data processing and signal control.

With this device, when the equipment connected to the vibration isolation device vibrates, the piezoelectric element 1 detects the vibration signal and transmits the vibration signal to the controller, and the controller judges the vibration state of the equipment according to the vibration signal; when the equipment When it is in the low-frequency and large-amplitude vibration area, it enters the semi-active vibration isolation control mode. At this time, the magneto-rheological damper starts, the piezoelectric element 1 self-locks, and the magnetorheological damper generates the damping force required for vibration isolation according to the vibration frequency; when When the equipment is in the high-frequency and small-amplitude vibration area, it enters the active vibration isolation control mode. At this time, the piezoelectric element 1 starts, the magnetorheological damper locks itself, and the piezoelectric element 1 generates the driving force required for vibration isolation according to the vibration frequency; therefore , this device can select a semi-active or active vibration isolation mode according to the current state of the vibration-isolated equipment, which effectively improves the overall vibration isolation effect and control accuracy; in addition, this device uses the deformation of the piezoelectric element 1 and the applied voltage The characteristics of the corresponding proportional relationship, on the one hand, the deformation of the piezoelectric element 1 can be controlled by controlling the applied voltage value, and it can be used as an active control element in the vibration isolation device to realize active control of vibration. On the other hand, the piezoelectric element 1 Under the action of external force, the amount of deformation is generated, and the force value of the piezoelectric element 1 is determined by the corresponding induced voltage value. It is used as a self-sensing element in the vibration isolation device, and real-time monitoring and feedback are applied to the device. The mechanical characteristics of external load and vibration realize the integration of semi-active vibration isolation control, active vibration isolation control and self-sensing in structure and function, and realize the real-time monitoring of intelligent vibration isolation control and mechanism vibration reduction response in the whole frequency range of the device. Monitoring reduces the complexity of control and meets the requirements of vibration isolation for high-precision equipment.

In this embodiment, the piezoelectric element 1 is connected in series with the magneto-rheological damper; series connection means that the piezoelectric element 1 is connected end-to-end with the magneto-rheological damper, for example, the piezoelectric element 1 can be connected in the magneto-rheological damper At the bottom of the cylinder 2, the central axis of the piezoelectric element 1 coincides with or is parallel to the central axis of the magnetorheological damper, so that the piezoelectric element 1 and the magnetorheological damper are in the same vibration isolation direction, improving the vibration isolation performance.

In this embodiment, the magneto-rheological damper includes a cylinder 2 and a piston 4 connected to an electromagnetic coil 3 inside the cylinder 2, and the gap between the side wall of the piston 4 and the inner wall of the cylinder 2 is filled with a magnet. A rheological body 5; a magneto-rheological body 5 is set between the cylinder 2 and the piston 4, and the reciprocating motion of the piston 4 drives the magneto-rheological body 5 to slide on the inner wall surface of the cylinder 2, and a magnetic field is generated after the electromagnetic coil 3 is energized. Larger, the greater the shear yield force of the magneto-rheological body 5, the greater the damping force of the magneto-rheological damper; in order to prevent the leakage of the magneto-rheological body 5, the side wall of the piston 4 can be set to accommodate the magneto-rheological body 5 At the same time, the seal is used for sealing; this structure is beneficial to reduce the use of traditional magnetorheological fluid, and the magnetorheological damper responds more quickly, and the damping and vibration isolation effect is better; the magnetorheological body 5 It is preferably magnetorheological foam, which can effectively improve the efficiency of magnetorheological work and avoid complicated sealing devices.

In the present embodiment, what is used to generate the magnetic field for controlling the magnetorheological body is a composite magnetic structure made up of permanent magnet 6 and electromagnetic coil 3; permanent magnet 6 is an annular permanent magnet; in the composite magnetic structure, the magnetic field produced by permanent magnet 6 and the magnetic field generated by the electromagnetic coil 3 respectively act on the magneto-rheological body 5 and superimpose to change the damping during the movement of the piston 4; by changing the magnitude and direction of the energized current of the electromagnetic coil 3, the relationship between the coil magnetic field and the permanent magnetic field can be changed The superposition method and superposition amplitude can realize the variable damping movement function and self-locking function of the magnetorheological damper in a wider range under the action of external load; the magnetic conduction element of the magnetorheological damper can be made of ferrite material, which is effective Improve the response time of the magneto-rheological damper; in the present embodiment, the middle part of the piston 4 is provided with a first ring groove for installing the permanent magnet 6 and a second ring groove for installing the electromagnetic coil 3 from inside to outside in the radial direction. The ring groove is convenient for the installation and replacement of magnetic parts; wherein, the first ring groove communicates with the second ring groove, and the electromagnetic coil 3 is partially wound on the permanent magnet 6; the first ring groove can include several circumferentially uniformly arranged and radial The section is a trapezoidal or directional unit slot, and the permanent magnet 6 is formed by placing several independent permanent magnet units in the unit slot to form an annular structure.

In this embodiment, the magneto-rheological damper further includes a piston rod 7 detachably connected to the piston 4, the piston rod 7 is provided with a first wire passing hole 7a arranged in the axial direction, and the piston 4 is provided with There is a second wire passing hole 4a communicated with the first wire passing hole, the wire of the electromagnetic coil 3 passes through the second wire passing hole and the first wire passing hole; one end of the piston rod 7 is connected with the piston 4, and the other end Pass through the top opening of the cylinder 2; the top opening of the cylinder 2 is also provided with an oil seal 8 and an end cover 9 for pressing the oil seal 8, the piston rod 7 passes through the oil seal 8 and the end cover 9 in turn, and the piston rod 7 A guide cylinder 10 can be set between the oil seal; the piston 4 is concaved toward the outer end surface of the piston rod 7 to form a connecting hole 11, and the piston rod 7 coaxially extends into the connecting hole and is threaded; the connecting hole is provided with an inner thread, the end of the piston rod 7 is provided with an external thread that matches the internal thread, and the piston rod 7 is connected to the piston 4 through a threaded manner. Vibration performance and adaptability.

At the same time, this embodiment also discloses a vibration isolation control method using the above broadband vibration isolation device, as shown in Figure 2, the vibration isolation control method includes the following steps:

A. Detect the vibration signal, and judge whether it is the vibration frequency and amplitude that needs vibration isolation. If so, go to the next step; install the above-mentioned broadband vibration isolation device on the equipment that needs vibration reduction, and connect the equipment with the vibration isolation device When vibration occurs, the piezoelectric element 1 detects the vibration signal and transmits the vibration signal to the controller; at this time, the piezoelectric element 1 acts as a vibration sensor;

B. Judging whether the vibration is in the high-frequency vibration and low-amplitude area, if so, go to the next step; the controller judges the vibration state of the equipment according to the vibration signal; the controller is preset with a program for processing the vibration signal, for example, Calculate the current frequency ratio, and judge the vibration state of the equipment by comparing the current frequency ratio with the actual frequency ratio, so as to choose to enter different vibration isolation modes; after the judgment, the controller also calculates the required control force according to the control algorithm , and then use the coordination algorithm for time-sharing control;

C. Judging the high-frequency vibration frequency and performing high-frequency active vibration isolation according to the vibration frequency, return to step B after vibration isolation; during high-frequency active vibration isolation, the controller sends a start signal to the piezoelectric element 1, and at the same time sends a signal to the magnetorheological damper A self-locking signal is issued, and the piezoelectric element 1 generates the driving force required for vibration isolation according to the high-frequency vibration frequency to buffer the vibration; at this time, the piezoelectric element 1 acts as a driver; the size of the driving force is also calculated by the controller , and adjust in real time;

D. In step B, if no, in the low-frequency vibration area, judge the low-frequency vibration frequency, perform low-frequency semi-active vibration isolation according to the low-frequency vibration frequency, and return to step B after vibration isolation; if the low-frequency semi-active vibration isolation is yes, the controller directs the magnetic current The variable damper sends a start signal, and at the same time sends a self-locking signal to the piezoelectric element 1, and the magnetorheological damper generates the damping force required for vibration isolation according to the low-frequency vibration frequency to buffer the vibration; the size of the damping force is calculated by the controller. and adjust in real time.

After the vibration of the equipment is properly buffered, both the magneto-rheological damper and the piezoelectric element 1 as a driver stop working, while the piezoelectric element 1 as a vibration sensor is always in a monitoring state in order to respond to vibration in real time.

As shown in Figure 3, taking the forced vibration of a single-degree-of-freedom system as an example (the present invention is not limited to a single-degree-of-freedom system, but can be applied to various fields related to vibration isolation), at this time in step B, when frequency ratio less than , it is a low-frequency vibration area, and the controller determines that the equipment is in a low-frequency and large-amplitude vibration area, that is, a resonance area. The amplitude of this area decreases with the increase of the damping coefficient, and the range of amplitude variation is large; when the frequency ratio is greater than or equal to , it is a high-frequency vibration area, and the controller determines that the equipment is in a high-frequency and small-amplitude vibration area, that is, the vibration isolation area. The amplitude of this area increases with the increase of the damping coefficient, but the overall amplitude is small.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (8)

1. A broadband vibration isolation device, characterized in that, comprising: Magneto-rheological dampers are used to generate damping force for semi-active vibration isolation when the equipment connected to the vibration isolation device is in the low-frequency and large-amplitude vibration region; The piezoelectric element, connected with the magneto-rheological damper, is used to generate driving force for active vibration isolation when the equipment connected to the vibration isolation device is in the high-frequency and small-amplitude vibration region, and is used to control the vibration isolation device. Vibration signals from connected devices are detected; and The controller is used to receive the vibration signal detected by the piezoelectric element, and control the magneto-rheological damper to generate a semi-active vibration-isolation damping force or control the piezoelectric element to generate an active vibration-isolation driving force according to the vibration signal. 2. The broadband vibration isolation device according to claim 1, wherein the piezoelectric element is connected in series with the magnetorheological damper. 3. The broadband vibration isolation device according to claim 1, characterized in that: the magneto-rheological damper comprises a cylinder and a piston disposed in the cylinder, and the gap between the side wall of the piston and the inner wall of the cylinder The area is filled with magnetorheological fluids. 4. The broadband vibration isolation device according to claim 3, wherein the magnetorheological fluid is magnetorheological foam. 5. The broadband vibration isolation device according to claim 3, characterized in that: the magnetic field used to generate and control the magnetorheological fluid is a composite magnetic structure composed of permanent magnets and electromagnetic coils. 6. The broadband vibration isolation device according to claim 5, characterized in that: the permanent magnet is an annular permanent magnet, and the middle part of the piston is sequentially provided with a first ring groove for installing the permanent magnet along the radial direction from inside to outside And the second ring groove for installing the electromagnetic coil. 7. A method of vibration isolation control using the broadband vibration isolation device described in any one of claims 1 to 6, characterized in that it comprises the following steps: A. Detect the vibration signal, and judge whether it is the vibration frequency and amplitude that require vibration isolation, and if so, go to the next step; B. Determine whether the vibration is in the high-frequency vibration and low-amplitude area, and if so, go to the next step; C. Judge the high-frequency vibration frequency and perform high-frequency active vibration isolation according to the vibration frequency, and return to step B after vibration isolation; D. In step B, if no, in the low-frequency vibration area, determine the low-frequency vibration frequency, perform low-frequency semi-active vibration isolation according to the low-frequency vibration frequency, and return to step B after vibration isolation. 8. The vibration isolation control method according to claim 7, characterized in that: in step B, when the frequency ratio is less than , it is the low frequency vibration region, when the frequency ratio is greater than or equal to , it is a high-frequency vibration region.