CN211293426U

CN211293426U - Multi-degree-of-freedom active mass damper vibration reduction system

Info

Publication number: CN211293426U
Application number: CN202020083332.1U
Authority: CN
Inventors: 孙京海
Original assignee: National Astronomical Observatories of CAS
Current assignee: National Astronomical Observatories of CAS
Priority date: 2020-01-15
Filing date: 2020-01-15
Publication date: 2020-08-18
Anticipated expiration: 2030-01-15

Abstract

The utility model provides a multi-degree-of-freedom active mass damper vibration attenuation system, which comprises a motion control device and an active mass damper; at least three active mass dampers are uniformly arranged on the device to be damped at intervals along the circumferential direction of the device to be damped, and the interval angles between every two adjacent active mass dampers are equal; each active mass damper is connected to the motion control device. The advantages are that: the active mass damper has good effect on all vibration modes, overcomes the defects of low rigidity and difficult realization of large stroke of the passive damper, and can provide excellent vibration damping effect.

Description

Multi-degree-of-freedom active mass damper vibration reduction system

Technical Field

The utility model relates to a vibration control field especially relates to a multi freedom initiative mass damper damping system.

Background

A500-meter-caliber spherical radio telescope (FAST) (figure 1) adopts a novel flexible supporting scheme to realize the functions of large-span, high-precision positioning and pointing of a feed source cabin; the feed cabin weighing 30 tons is suspended and dragged by using 6 steel cables to complete a large range of movement.

This flexible suspension system is very low in frequency and is susceptible to vibration excited by external disturbances. The vibration of the feed source cabin can be reduced by increasing the damping of the feed source supporting structure through a feasible means, and the method is one effective way for improving the positioning and pointing accuracy. On the premise of the existing support scheme, it is difficult to improve the damping of the structure itself, so additional vibration control equipment needs to be considered.

The mass damper is directly installed on equipment needing vibration suppression without connecting an additional foundation, has good effectiveness and reliability, and is widely applied to high-rise buildings, bridges and mechanical equipment with vibration. In the field of astronomical telescopes, there are also examples of applications for mass dampers, such as: the Arecobo telescope with a similar cable support structure as FAST uses a "Stockbridge" damper.

Compared to the application environment of high-rise buildings, bridges and arecobo telescopes, FAST has three significant differences: firstly, the working position of the FAST feed source cabin is always changed, so that the vibration mode and frequency of a cable supporting structure of the FAST feed source cabin are continuously changed, the working effect of the passively working tuned mass damper is limited, and if a plurality of tuned mass dampers work cooperatively, excessive load pressure is inevitably added to the feed source cabin, so that the FAST feed source cabin is not feasible; secondly, the vibration characteristic of the FAST feed cabin is the compound motion of 6 degrees of freedom in space. Therefore, the structure and layout of its mass damper would be completely different from conventional applications; finally, the vibration frequency that FAST needs to suppress is very low, in the range of 0.1-1Hz, which brings great difficulty to the parameter design of the mass damper.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a multi freedom initiative mass damper damping system to solve the aforementioned problem that exists among the prior art.

In order to realize the purpose, the utility model discloses a technical scheme as follows:

a vibration reduction system of a multi-degree-of-freedom active mass damper comprises a motion control device and an active mass damper; at least three active mass dampers are uniformly arranged on the device to be damped at intervals along the circumferential direction of the device to be damped, and the interval angles between every two adjacent active mass dampers are equal; each active mass damper is connected to the motion control device.

Preferably, the active mass damper comprises a mounting plate, a mass block, a position sensor, an acceleration sensor and a driving device, wherein at least two motion guide rails are arranged on one side of the mounting plate parallel to the height direction of the mounting plate at intervals, and the motion guide rails extend along the height direction of the mounting plate; the mass block is provided with at least two guide holes penetrating through the upper side and the lower side of the mass block along the moving direction of the mass block, and each moving guide rail correspondingly extends into the corresponding guide hole respectively so that the mass block can slide up and down along the moving guide rails; the mass block is connected with the driving device and the position sensor, and the driving device, the position sensor and the acceleration sensor are all fixed on the mounting plate.

Preferably, the driving device is connected with the motion control device through a motor control cable; the acceleration sensor is connected with the motion control device through an acceleration signal line; the position sensor is connected with the motion control device through a position signal wire.

Preferably, the active mass damper further comprises a displacement limiting block, and the displacement limiting block is fixed on the mounting plate; the displacement limiting block is arranged in the stroke range of the mass block.

Preferably, the driving device and the position sensor are arranged on two opposite sides of the mounting plate parallel to the height direction of the mounting plate, and the sides of the driving device and the position sensor are perpendicular to the side of the motion guide rail.

Preferably, the driving device is a linear motor, a rotor of the linear motor is connected with the mass block, a stator of the linear motor is fixed on the mounting plate, and at least one displacement limiting block in contact with the upper end of the stator is arranged above the stator; and at least one displacement limiting block which is contacted with the lower end of the stator is arranged below the stator.

Preferably, at least two acceleration sensors are arranged on the side, opposite to the side where the motion guide rail is located, of the mounting plate, and the acceleration sensors are arranged at intervals along the height direction of the mounting plate.

Preferably, the motion control device comprises a motion controller and at least three motor drivers, and each motor driver is connected with the motion controller; each motor driver is respectively connected with the driving device in each active mass damper through a motor control cable; the acceleration sensor is connected with the motion controller through the acceleration signal line, and the position sensor is connected with the motion controller through the position signal line.

The utility model has the advantages that: the active mass damper has good effect on all vibration modes, and overcomes the defects of low rigidity and difficult realization of variable frequency of a passive damper; the vibration can be greatly reduced, and the feed source cabin can be kept to stably move.

Drawings

Fig. 1 is a schematic diagram of a spherical radio telescope (FAST) with a caliber of 500 meters in an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an active mass damper damping system according to an embodiment of the present invention;

fig. 3 is a schematic view of another perspective structure of an active mass damper damping system according to an embodiment of the present invention;

FIG. 4 is a schematic view of the rotation of the rotating shaft in the horizontal plane in an embodiment of the present invention;

fig. 5 is a schematic view of the rotation of the rotating shaft in the vertical direction of the horizontal plane and the translation in the vertical direction of the horizontal plane in the embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a vibration damping system of an active mass damper used in a feed cabin according to an embodiment of the present invention;

fig. 7 is a schematic view of another structure of the active mass damper damping system used in the feed cabin according to the embodiment of the present invention;

FIG. 8 is a graph comparing time domain vibration response curves for feed cabin vertical axis direction translational degree of freedom vibration with and without an active mass damper damping system in an embodiment of the present invention;

FIG. 9 is a graph comparing time domain vibration response curves for feed cabin horizontal axis direction rotational degree of freedom vibration with and without the active mass damper damping system in an embodiment of the present invention;

fig. 10 is a time domain vibration response plot comparison of feed capsule edge position vibration with and without an active mass damper damping system in an embodiment of the invention.

In the figure: 1. a feed source cabin; 2. a suspension rope; 3. an active mass damper; 4. mounting a plate; 41. a first side surface; 42. a second side surface; 43. a third side; 44. a fourth side; 45. a fixed head; 5. a fixing sheet; 6. a moving guide rail; 7. a mass block; 8. an acceleration sensor; 9. a position sensor; 10. a stator; 11. a displacement limiting block; 12. and (4) a guide hole.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the invention, are given by way of illustration only.

Example one

As shown in fig. 2 to 3, the present embodiment provides a multiple degree of freedom active mass damper vibration damping system, which includes a motion control device and an active mass damper 3; at least three active mass dampers 3 are uniformly arranged on the device to be damped along the circumferential direction at intervals, and the angles of the intervals between every two adjacent active mass dampers 3 are equal; each of the active mass dampers 3 is connected to the motion control means.

In this embodiment, the vibration damping system is in the in-process of using, and the number of initiative mass damper 3 can set up according to the demand of reality, and initiative mass damper 3 sets up in waiting to the periphery of vibration damper, and sets up along its even interval of circumference, guarantees that initiative mass damper 3 can not influence its damping effect owing to the reason that sets up the position.

In this embodiment, the active mass damper 3 includes a mounting plate 4, a mass block 7, a position sensor 9, an acceleration sensor 8 and a driving device, at least two motion guide rails 6 are arranged on one side of the mounting plate 4 parallel to the height direction of the mounting plate at intervals, and the motion guide rails 6 extend along the height direction of the mounting plate 4; the mass block 7 is provided with at least two guide holes 12 penetrating through the upper side and the lower side of the mass block along the moving direction of the mass block, and each motion guide rail 6 correspondingly extends into the corresponding guide hole 12 respectively so that the mass block 7 slides up and down along the motion guide rails 6; the mass block 7 is connected with the driving device and the position sensor 9, and the driving device, the position sensor 9 and the acceleration sensor 8 are all fixed on the mounting plate 4.

In this embodiment, the driving device is connected to the motion control device via a motor control cable; the acceleration sensor 8 is connected with the motion control device through an acceleration signal line; the position sensor 9 is connected to the motion control device via a position signal line.

In this embodiment, the active mass damper 3 further includes a displacement limiting block 11, and the displacement limiting block 11 is fixed on the mounting plate 4; the displacement limiting block 11 is arranged in the stroke range of the mass block 7.

In this embodiment, the driving device and the position sensor 9 are disposed on two opposite sides of the mounting plate 4 parallel to the height direction thereof, and the sides of the driving device and the position sensor 9 are perpendicular to the side of the moving guide rail 6.

In this embodiment, the driving device is a linear motor, a rotor of the linear motor is connected with the mass block 7, a stator 10 of the linear motor is fixed on the mounting plate 4, and at least one displacement limiting block 11 contacting with the upper end of the stator 10 is arranged above the stator 10; at least one displacement limiting block 11 contacting with the lower end of the stator 10 is arranged below the stator 10.

In this embodiment, at least two acceleration sensors 8 are disposed on the side of the mounting plate 4 opposite to the side where the motion guide rail 6 is disposed, and the acceleration sensors 8 are disposed at intervals in the height direction of the mounting plate 4.

As shown in fig. 2, in the present embodiment, the mounting plate 4 includes a rectangular parallelepiped mounting bar and fixing heads fixed at the upper and lower ends of the mounting bar, and the side surface of the mounting bar parallel to the height direction includes a first side surface 41 and a second side surface 42 which are parallel and opposite to each other, and a third side surface 43 and a fourth side surface 44 which are parallel and opposite to each other. Two moving guide rails 6 are arranged on the side of the first side surface 41, the two moving guide rails 6 extend along the height direction of the mounting bar, and a certain distance is reserved between the two moving guide rails 6 and the first side surface 41. The mass block 7 is provided with guide holes 12 corresponding to the motion guide rails 6, and the two motion guide rails 6 respectively and correspondingly extend into the two guide holes 12, so that the mass block 7 can move up and down along the motion guide rails 6.

In the present embodiment, the stator 10 of the linear motor and the position sensor 9 are respectively disposed on the third side 43 and the fourth side 44, that is, the stator 10 of the linear motor and the position sensor 9 are both disposed on the third side 43 and the fourth side 44 of the mounting bar opposite to each other; the stator 10 of the linear motor extends to the first side surface 41, the mover of the linear motor can move up and down along the stator 10, and the mover of the linear motor is fixedly connected with one side of the mass block 7 close to the first side surface 41 and can drive the mass block 7 to move up and down along the motion guide rail 6.

In this embodiment, the fixing head 45 is trapezoidal, one end of the fixing head 45 with a wider size extends out of the first side surface 41 of the mounting bar, two fixing pieces 5 are arranged on each fixing head 45 at intervals, the two fixing pieces 5 located on the upper end fixing head 45 respectively correspond to the two fixing pieces 5 located on the upper end of the fixing head 45 at the lower end, and a moving guide rail 6 is fixed between the two fixing pieces 5 corresponding up and down. Guide holes 12 penetrating through the upper side and the lower side of the mass block 7 are arranged in a direction parallel to the motion guide rails 6, the two motion guide rails 6 correspondingly extend into the two guide holes 12 respectively, and the motion guide rails 6 provide a guiding function and a supporting function for the movement of the mass block 7.

In this embodiment, two displacement limiting blocks 11 are arranged on the mounting plate 4, the two displacement limiting blocks 11 are respectively arranged on the mounting plate 4 at the upper end and the lower end of the linear motor, and the two displacement limiting blocks 11 are respectively contacted with the two ends of the stator 10 of the linear motor. The two acceleration sensors 8 are both arranged on the second side surface 42, and the two acceleration sensors 8 are respectively positioned at the same height with the two displacement limiting blocks 11.

In this embodiment, the motion control device includes a motion controller and at least three motor drivers, and each of the motor drivers is connected to the motion controller; each motor driver is respectively connected with the driving device in each active mass damper 3 through a motor control cable; the acceleration sensor 8 is connected with the motion controller through the acceleration signal line, and the position sensor 9 is connected with the motion controller through the position signal line.

Example two

As shown in fig. 4 to 10, the feed cabin 1 is suspended by 6 suspension ropes 2, and is balanced under the self-gravity. The vibration of the feed source cabin 1 is characterized by 6 degrees of freedom in a 3-dimensional space, and the vibration is a result of compounding of multi-modal vibration of 6 cables. The main influence factors of the vibration of the feed source cabin 1 can be found through dynamic analysis aiming at the cabin cable structure: the most significant modes include rotation along the axis of rotation in the horizontal plane (fig. 4), rotation along the axis of rotation perpendicular to the horizontal plane, and translation perpendicular to the horizontal plane (fig. 5).

The torsion of the feed source cabin 1 along a horizontal axis is a primary vibration mode, the frequency is low, and the influence on the precision is also the largest. High translation frequencies along a vertical axis to the horizontal may also affect accuracy. These two vibrations should be the primary objects of vibration suppression.

For the main vibration mode of the feed source cabin 1, the positions with the maximum motion response are all at the edge of the horizontal direction, and the motion direction is along the vertical direction. The active mass dampers 3, which are arranged at the positions of maximum motion response, can significantly absorb the cabin vibrations and increase the damping, as a result of which the cables and other secondary cabin vibrations can also be significantly damped.

In the embodiment, the feed source cabin 1 is a device to be damped, and if a damping system is used for damping the feed source cabin 1, three active mass dampers 3 are required to be arranged at intervals on the periphery of the feed source cabin 1; the angles of the two adjacent active mass dampers 3 are the same; as shown in fig. 6 and 7.

In this embodiment, the active mass dampers 3 moving in the vertical direction are uniformly arranged near the edge in the feed source cabin 1. The feed source cabin 1 is connected to a support tower through a suspension rope 2. The total mass of the masses 7 of the three active mass dampers 3 is by default 1/10 of the mass of the cabin, which needs to be adjusted according to the actual stroke space that can be provided in the cabin. The principle is that the smaller the mass 7, the longer the required stroke. For active vibration suppression, closed-loop velocity feedback is used, i.e. the driving force driving the mass 7 is proportional to the speed of movement of the mass 7 in the moving guide 6. The speed information is differentiated from the acceleration sensor 8 or the outboard position measurement. Furthermore, the movement of the mass 7 requires the displacement sensor to provide balance point and offset distance information. The equilibrium position of the mass 7 is provided by the steady-state moment of the drive.

In the embodiment, the working process of the active mass damper vibration reduction system is that in the up-and-down moving process of the feed source cabin 1, the active mass damper 3 moves along with the feed source cabin 1, the acceleration sensor 8 on the active mass damper 3 detects the up-and-down moving acceleration of the feed source cabin 1 and feeds the acceleration back to the motion controller through the acceleration signal line, the motion controller integrates the acceleration into speed according to the acceleration of the feed source cabin 1 and controls the linear motor to act in proportion, the rotor of the linear motor provides a driving force for the mass block 7, and the driving force drives the mass block 7 to move up and down along the motion guide rail 6 so as to reduce the vibration of the feed source cabin 1; meanwhile, the position sensor 9 can acquire the distance of the mass block 7 deviating from the middle position in real time to control the moving speed, and the farther the distance, the lower the outward deviation driving force and the higher the inward returning driving force are, so that when the mass block 7 deviates from the middle position too much, part of vibration damping effect is reduced, but the mass block 7 can be kept to work near the initial middle position all the time.

In this embodiment, after the active mass damper vibration reduction system is used, the translational damping ratio in the vertical axis direction is increased from 0.002 when no mass damper is provided to 0.035 (time-domain vibration response is shown in fig. 8, the dotted line indicates that no active mass damper vibration reduction system is used; the solid line indicates that an active mass damper vibration reduction system is used), and the rotational damping ratio in the horizontal axis direction is increased from 0.004 to 0.14 (time-domain vibration response is shown in fig. 9, the dotted line indicates that no active mass damper vibration reduction system is used; the solid line indicates that an active mass damper vibration reduction system is used). The vibration response measured at the edge position of the feed capsule 1 is seen to increase the damping ratio at 0.35Hz and 0.85Hz to 0.12 and 0.035 respectively (time domain vibration response is as shown in fig. 10, dashed line for not using the active mass damper damping system; solid line for using the active mass damper damping system). As can be seen from fig. 8 to 10, after the active mass damper 3 is installed on the feed source cabin 1, the vibration is greatly reduced, the motion stability of the feed source cabin 1 is improved, the active mass damper 3 has a good effect on all vibration modes, and the defects that the passive damper has low rigidity and large stroke is not easy to realize are overcome.

Through adopting the utility model discloses an above-mentioned technical scheme has obtained following profitable effect:

the utility model provides a multi-degree-of-freedom active mass damper vibration reduction system, wherein the active mass damper has good effect on all vibration modes and overcomes the defects of low rigidity and difficult realization of frequency conversion of a passive damper; the vibration can be greatly reduced, and the feed source cabin can be kept to stably move.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be viewed as the protection scope of the present invention.

Claims

1. A multi-degree-of-freedom active mass damper vibration reduction system is characterized in that: comprises a motion control device and an active mass damper; at least three active mass dampers are uniformly arranged on the device to be damped at intervals along the circumferential direction of the device to be damped, and the interval angles between every two adjacent active mass dampers are equal; each active mass damper is connected to the motion control device.

2. The multiple degree of freedom active mass damper vibration canceling system of claim 1 wherein: the active mass damper comprises a mounting plate, a mass block, a position sensor, an acceleration sensor and a driving device, wherein at least two motion guide rails are arranged on one side of the mounting plate parallel to the height direction of the mounting plate at intervals, and extend along the height direction of the mounting plate; the mass block is provided with at least two guide holes penetrating through the upper side and the lower side of the mass block along the moving direction of the mass block, and each moving guide rail correspondingly extends into the corresponding guide hole respectively so that the mass block can slide up and down along the moving guide rails; the mass block is connected with the driving device and the position sensor, and the driving device, the position sensor and the acceleration sensor are all fixed on the mounting plate.

3. The multiple degree of freedom active mass damper vibration canceling system of claim 2, wherein: the driving device is connected with the motion control device through a motor control cable; the acceleration sensor is connected with the motion control device through an acceleration signal line; the position sensor is connected with the motion control device through a position signal wire.

4. The multiple degree of freedom active mass damper vibration canceling system of claim 3, wherein: the active mass damper also comprises a displacement limiting block, and the displacement limiting block is fixed on the mounting plate; the displacement limiting block is arranged in the stroke range of the mass block.

5. The multiple degree of freedom active mass damper vibration canceling system of claim 4, wherein: the driving device and the position sensor are arranged on two opposite sides of the mounting plate parallel to the height direction of the mounting plate, and the sides of the driving device and the position sensor are perpendicular to the sides of the motion guide rails.

6. The multiple degree of freedom active mass damper vibration canceling system of claim 5, wherein: the driving device is a linear motor, a rotor of the linear motor is connected with the mass block, a stator of the linear motor is fixed on the mounting plate, and at least one displacement limiting block which is in contact with the upper end of the stator is arranged above the stator; and at least one displacement limiting block which is contacted with the lower end of the stator is arranged below the stator.

7. The multiple degree of freedom active mass damper vibration canceling system of claim 6, wherein: at least two acceleration sensors are arranged on one side of the mounting plate opposite to the side where the motion guide rail is located, and the acceleration sensors are arranged at intervals along the height direction of the mounting plate.

8. The multiple degree of freedom active mass damper vibration canceling system of claim 7, wherein: the motion control device comprises a motion controller and at least three motor drivers, and each motor driver is connected with the motion controller; each motor driver is respectively connected with the driving device in each active mass damper through a motor control cable; the acceleration sensor is connected with the motion controller through the acceleration signal line, and the position sensor is connected with the motion controller through the position signal line.