LU500517B1 - Micro-vibration suppression platform based on intelligent piezoelectric arrays and method for controlling same - Google Patents
Micro-vibration suppression platform based on intelligent piezoelectric arrays and method for controlling same Download PDFInfo
- Publication number
- LU500517B1 LU500517B1 LU500517A LU500517A LU500517B1 LU 500517 B1 LU500517 B1 LU 500517B1 LU 500517 A LU500517 A LU 500517A LU 500517 A LU500517 A LU 500517A LU 500517 B1 LU500517 B1 LU 500517B1
- Authority
- LU
- Luxembourg
- Prior art keywords
- micro
- platform
- piezoelectric
- vibration
- piezoelectric stack
- Prior art date
Links
- 230000001629 suppression Effects 0.000 title claims abstract description 60
- 238000003491 array Methods 0.000 title claims abstract description 18
- 238000000034 method Methods 0.000 title claims description 23
- 230000001133 acceleration Effects 0.000 claims description 20
- 238000002955 isolation Methods 0.000 claims description 19
- 230000008569 process Effects 0.000 claims description 11
- 238000011156 evaluation Methods 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 7
- 230000008859 change Effects 0.000 claims description 4
- 238000013507 mapping Methods 0.000 claims description 3
- 239000011159 matrix material Substances 0.000 claims description 3
- 230000033001 locomotion Effects 0.000 abstract description 4
- 230000005284 excitation Effects 0.000 description 11
- 238000006073 displacement reaction Methods 0.000 description 9
- 238000004088 simulation Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 6
- 230000006870 function Effects 0.000 description 6
- 238000013016 damping Methods 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 4
- 229910010293 ceramic material Inorganic materials 0.000 description 3
- 238000009434 installation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 238000010008 shearing Methods 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012636 effector Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229910001285 shape-memory alloy Inorganic materials 0.000 description 1
- 239000002520 smart material Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
- F16F15/04—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means
- F16F15/08—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means with rubber springs ; with springs made of rubber and metal
- F16F15/085—Use of both rubber and metal springs
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/005—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion using electro- or magnetostrictive actuation means
- F16F15/007—Piezoelectric elements being placed under pre-constraint, e.g. placed under compression
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/005—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion using electro- or magnetostrictive actuation means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/002—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion characterised by the control method or circuitry
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
- F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
- F16F15/022—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using dampers and springs in combination
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Aviation & Aerospace Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Vibration Prevention Devices (AREA)
Abstract
The present invention discloses a micro-vibration suppression platform based on intelligent piezoelectric arrays, comprising an upper platform, a lower platform, and primary dampers and secondary dampers evenly distributed between the upper platform and the lower platform; the primary dampers and the secondary dampers are inclined, and extension lines of axes of the primary dampers intersect at one point above the upper platform; the damper comprises an outer sleeve, a spindle rod located in a central axis of the damper and a piezoelectric stack array arranged in the middle of the outer sleeve, wherein the piezoelectric stack array comprises at least two piezoelectric stacks symmetrically distributed relative to the spindle rod, and the center of the array is hollow. In the present invention, control and suppression of micro-vibration signals in 6 degrees of freedom are implemented, and thus comprehensive suppression of micro-vibration signals from different directions and motion dimensions is achieved, which greatly improves the reliability of the vibration suppression platform. For micro-vibration signals with low frequency, anisotropy and randomness, precise suppression in different directions and dimensions is achieved.
Description
MICRO-VIBRATION SUPPRESSION PLATFORM BASED ON INTELLIGENT 17500517
TECHNICAL FIELD The present invention relates to a platform and a method for controlling the same, and in particular to a micro-vibration suppression platform based on intelligent piezoelectric arrays and a method for controlling the same.
BACKGROUND The rapid development of high technologies such as optical communication technology, aerospace technology, biomedical technology, ultra-precision machining and the like urgently needs a precise mechanical system with high precision and high stability, and the micro-vibration control technology has become one of the important bottlenecks restricting the precision and the stability of the system. The micro-vibration refers to a micro disturbance with small vibration amplitude (generally < 10 micrometers) and wide frequency band (0.1-200 Hz). The cause of micro-vibration is very complicated. It may be caused by either coupling inside the system or excitation outside the system. In a mechanical system, especially a precision mechanical system, micro-vibration greatly affects the actuation precision and stability of the end effector of the system. For example, in the field of optics and precise engineering, the six-degree-of-freedom positioning platform currently used in China for optical fiber packaging positioning has a positioning precision of up to 100 nm, which is far lower than that (20 nm) of the optical fiber positioning platform of NEWPORT, USA. Relevant research shows that micro-vibration of the precise positioning platform and external interference are major factors influencing the positioning precision of the platform. The micro-vibration is typically characterized by a low frequency (even ultra-low), a wide frequency domain, a tiny amplitude, multiple degrees of freedom, randomness and anisotropy. The micro-vibration has a great influence on the precision and stability of a high-precision system, and the control of micro-vibration has become one of the key basic problems of high-end technical equipment including the precise mechanical system. In the conventional vibration control method, means such as a vibration isolation device, a damping vibration absorber and a filtering module are used to implement suppression and control of vibration signals. However, they are only suitable for vibration signals with great amplitude and concentrated frequency range, and has strict requirements on the vibration speed, installation space and the like. As the space for installing the vibration isolation device in the precise mechanical system 1s generally limited and the micro-vibration has the characteristics of a tiny amplitude, a wide frequency domain and multiple degrees of freedom, the conventional vibration detection technology and control method barely meet the performance requirements for high precision and high stability of the precise mechanical system. For this reason, it is necessary to search and explore a more effective method for the micro-vibration control. Currently, most of the investigated smart materials include piezoelectric ceramic materials, electro (magnetic)-rheological fluids, magnetostrictive materials, shape memory alloys, and the like. The piezoelectric ceramic material has the advantages of excellent comprehensive performance, a wide working frequency band, a high response speed, a high actuation precision, stable performance, simple control and the like. The piezoelectric intelligent structure, designed by utilizing the sensing and actuating characteristics of the piezoelectric ceramic material for vibration control, is of increasing interest to researchers in China and overseas. However, as only one piezoelectric stack is provided in the existing damper made of piezoelectric materials, the damper has the disadvantages of a small application range, and a poor sensing and suppression effect on the micro-vibration signals with low frequency, anisotropy and large randomness.
SUMMARY Purpose: The present invention is directed to provide a comprehensive, efficient and precise micro-vibration suppression platform based on intelligent piezoelectric arrays and a method for controlling the same.
Technical Scheme: The present invention provides a micro-vibration suppression platform based on intelligent piezoelectric arrays, comprising an upper platform, a lower platform, and primary dampers and secondary dampers evenly distributed between the upper platform and the lower platform, wherein the primary dampers and the secondary dampers are inclined and arranged alternately, and extension lines of axes of the primary dampers intersect at one point above the upper platform, a projection of the point on the upper platform coincides with a center of the upper platform; the damper comprises an outer sleeve, a spindle rod located in a central axis of the damper and a piezoelectric stack array arranged in the middle of the outer sleeve and provided with one spindle rod at each of the two ends thereof, the piezoelectric stack array comprises at least two piezoelectric stacks symmetrically distributed relative to the spindle rod, and the center of the array is hollow.
Four primary dampers and four secondary dampers are provided, six of which are moving rods, and the primary dampers and the secondary dampers are alternately distributed. A projection of the axis of the secondary damper on the lower platform is parallel to a projection of the axis of one adjacent primary damper on the lower platform, and is 00517 perpendicular to a projection of the axis of the other adjacent primary damper on a surface of the lower platform.
Between the two ends of the piezoelectric stack array and one end of the spindle rod is provided a first stop, and between the spindle rod and the outer sleeve is provided a linear bearing and a second stop; the linear bearing is arranged at the end of the spindle rod, the second stop is arranged in the middle of the spindle rod, and between the second stop and the linear bearing is provided a preloaded spring.
The damper comprises a passive vibration isolation segment with one end contacting against one end of the outer sleeve and the other end contacting against the second stop.
A surface of the first block facing away from the piezoelectric stack array is provided with a concave arc, and one end of the spindle rod is of a convex arc shape corresponding to the concave arc.
The spindle rod comprises an expanding segment at one end and a body segment, the expanding segment having a diameter greater than that of the body segment.
The linear bearing is arranged between the expanding segment and the outer sleeve, and the preloaded spring has one end contacting against a platform where the expanding section protrudes.
One end of the spindle rod is arranged to extend out of the outer sleeve and provided with a connecting disc; the upper platform and the lower platform are provided with connecting seats for fixing the connecting discs; the connecting disc is perpendicular to the spindle rod, and the surface of the connecting seat is inclined.
A lower surface of the upper platform is provided with a detection unit and a control unit; the detection unit comprises a number of acceleration sensors corresponding to that of the dampers for detecting vibration signals; the control unit comprises a piezoelectric stack driver, a piezoelectric stack controller and an industrial personal computer; the industrial personal computer outputs a control signal according to the received vibration signal and an internal control algorithm to control the piezoelectric stack driver; the piezoelectric stack driver processes the received control signal and outputs a driving signal to drive the piezoelectric stack inside the moving rod to work.
The present invention further provides a method for controlling a micro-vibration suppression platform based on intelligent piezoelectric arrays. The method is based on the micro-vibration suppression platform based on the intelligent piezoelectric arrays described above and based on a multi-objective fuzzy (MOF) control algorithm, and specifically comprises the following steps: (1) taking the deviation and the deviation change rate between an actual position and an expected position of each piezoelectric stack as input, and taking an input voltage variation of the controller designated for the piezoelectric stack as output; (2) fuzzifying each input and output using a fuzzy-constrained trapezoidal membership function; establishing factor sets and evaluation sets, and establishing a single-factor fuzzy judgment matrix by mapping the factor sets to the evaluation sets; (3) establishing weight sets for the factor sets, and finally establishing fuzzy comprehensive evaluation sets, and thus the fuzzy relationship between the fuzzy input and output; (4) giving a fuzzy value for the output of the controller by fuzzy reasoning according to the fuzzy relationship; and (5) converting the fuzzy value into a precise value by defuzzifier and outputting the precise value to the controller designated for the piezoelectric stack to achieve precise control of each piezoelectric stack.
Beneficial Effects: The present invention has the following remarkable advantages compared with the prior art: (1) In the present invention, an 8-connecting rod parallel structure is adopted to achieve 6 degrees of freedom in the upper platform, and control and suppression of micro-vibration signals in the 6 degrees of freedom, thereby achieving comprehensive suppression of micro-vibration signals from various directions and motion dimensions; the 8-connecting rod parallel structure adopted in the vibration suppression platform has two additional connecting rods as redundant backups on the basis of a conventional 6-connecting rod structure, and the redundant backups function through redundant driving and control: when the piezoelectric stacks in any 1 or 2 rods of the 8 rods fail or are damaged, the redundant connecting rods function to ensure the functions and performance of the whole platform are not affected, which greatly improves the reliability of the vibration suppression platform. For micro-vibration signals with low frequency, anisotropy and randomness, precise suppression in different directions and dimensions is achieved.
(2) In the present invention, control and suppression of micro-vibration signals in 6 degrees of freedom can be achieved by combining primary dampers with secondary dampers. As the primary damper and the secondary damper have different control and suppression efficiencies to micro-vibration signals from each degree of freedom direction, the mutual compensation of the 00517 primary damper and the secondary damper improves the moving efficiency of the micro-vibration suppression platform in 6 degrees of freedom and thus the sensitivity of the micro-vibration suppression.
5 (3) The vibration suppression effect of the dampers according to the present invention is improved by combining passive vibration isolation and active vibration isolation, when the connecting disc is vibrated and thus the spindle rod is displaced, the spindle rod is subject to the friction of the rubber damping module, and thus part of vibration signal displacement is offset, thereby achieving passive vibration isolation; meanwhile, the acceleration sensor arranged on the parallel platform transmits a measured vibration signal to the industrial personal computer to control the piezoelectric stack to drive the spindle rod, such that the parallel platform moves to offset micro-vibration, thereby achieving active vibration isolation. The micro-vibration can be suppressed through the above process.
(4) Another surface of the back stop facing away from the piezoelectric stack component according to the present invention is configured to have a concave arc shape, and one end of the expanding connector of the spindle rod is configured to have a convex arc shape that is associated with the concave arc shape. Therefore, the back stop is tangentially connected to the spindle rod, which ensures the reliability of the piezoelectric stack and effectively prevents the piezoelectric stack from being damaged by shearing force.
(5) The part of the spindle rod according to the present invention between the connecting disc and the outer sleeve is similar to a flexible hinge structure characterized by no friction and no abrasion due to its small diameter, and therefore is capable of achieving micro-amplitude displacement transmission and output with high sensitivity. Two ends of the damper disclosed herein are configured as flexible hinge structures, which can effectively improve the universality of the intelligent structure, and respond to and suppress vibration signals of high, medium and low frequency, ensuring the stability and reliability of the performance of precision instrument under interference of micro-vibration.
(6) Given the fact that the micro-vibration signal has the characteristics of multiple degrees of freedom and anisotropy, a piezoelectric array intelligent structure is adopted in the structure disclosed herein to replace the conventional single piezoelectric stack; three piezoelectric stacks are used to form an annular array intelligent structure to effectively suppress micro-vibration 00517 signals that come from various directions and have multiple degrees of freedom, thereby improving the suppression effect on micro-vibration.
(7) Given the fact that more piezoelectric stacks are present, that the piezoelectric stacks in the same integrated active-passive damper have a synchronous relationship, and that the piezoelectric stacks in different integrated active-passive dampers are also coupled, the present invention adopts a multi-objective fuzzy control algorithm for the complex control of the piezoelectric stacks, which effectively controls the piezoelectric stacks and better achieves the active control of micro-vibration.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the present invention; FIG. 2 is a top view of the present invention; FIG. 3 is a cross-sectional view of the integrated active-passive damper according to the present invention; FIG. 4 is a schematic of a controlling process of the active vibration isolation according to the present invention; FIG. 5 is a schematic of a layout of the piezoelectric stack components in the integrated active-passive damper according to the present invention; FIG. 6 is a control model diagram for simulation comparison of the micro-vibration suppression platform according to the present invention and a conventional micro-vibration suppression platform; FIG. 7 is a comparison graph of the simulation results under excitation of a translational interference signal according to the present invention; FIG. 8 is a detailed view of the comparison graph of the simulation results under excitation of a translational interference signal according to the present invention; FIG. 9 is a comparison graph of the simulation results under excitation of a rotational interference signal of the present invention and the conventional micro-vibration suppression platform; and FIG. 10 is a detailed view of the comparison graph of the simulation results under excitation of a rotational interference signal of the present invention and the conventional micro-vibration suppression platform. 17900817
DETAILED DESCRIPTION The technical scheme of the present invention is further described below with reference to the drawings.
As shown in FIG. 2, in this embodiment, the present invention comprises an upper platform 11, a lower platform 13, and eight dampers 10 evenly distributed on the upper platform 11 and the lower platform 13, wherein the dampers 10 comprise four primary dampers and four secondary dampers, which are alternately distributed.
The diameter of the upper platform 11 is smaller than the diameter of the lower platform 13.
Each damper 10 has one end mounted to the upper platform 11 and the other end mounted to the lower platform 13.
The eight dampers 10 comprise four primary dampers and four secondary dampers, and the four primary dampers and the four secondary dampers are separately in axial symmetry. The four primary dampers are evenly distributed around the platform at interval angles of 90°. Extension lines of axes of the four primary dampers intersect at one point, a projection of which on a surface of the upper platform coincides with a center of the upper platform. The four secondary dampers are distributed evenly around the platform at interval angles of 90° and alternately with the four primary dampers. A projection of an axis of the secondary damper on the surface of the lower platform 13 is parallel to a projection of the axis of one adjacent primary damper on the surface of the lower platform 13, and is perpendicular to a projection of the axis of the other adjacent primary damper on the surface of the lower platform 13. An extension line of the axis of each secondary damper intersects at one point with the extension line of the axis of one of the adjacent primary dampers. The mutual compensation of the four primary dampers and the four secondary dampers improves the moving efficiency of the platform in 6 degrees of freedom and thus the sensitivity of the micro-vibration suppression. Therefore, in the present invention, a spatially gathering structure is employed for the eight dampers. When the upper platform is vibrated, the connecting discs are vibrated, such that when the spindle rod is displaced, the spindle rod is subject to the friction of the rubber damping module, and thus part of vibration signal displacement is offset, thereby achieving passive vibration isolation. Meanwhile, a vibration sensor arranged on the parallel platform transmits a measured signal to a controller, the controller outputs a driving signal through a control algorithm to a power amplifier designated for the piezoelectric stack, the power amplifier amplifies the control signal to drive the piezoelectric stack, and the piezoelectric stack converts the received electric signal into output displacement to drive the spindle rod. As such, the parallel platform produces movement to offset the micro-vibration, thereby achieving active vibration isolation. The micro-vibration can be suppressed through the above process.
The damper in this embodiment is an integrated active-passive damper, comprising an outer sleeve 9, a piezoelectric stack array 8, a passive vibration isolation segment 3, a linear positioning bearing 6, a preloaded spring 5, a spindle rod 2, a connecting disc 1, a first stop 7 and a second stop 4.
The piezoelectric stack array 8 performs active vibration isolation using piezoelectric stacks, and is internally arranged in the middle of the outer sleeve 9. The piezoelectric stack array 8 together with the first stop 7 positioned at two ends of the piezoelectric stack array 8 constitutes an active vibration isolation segment of the damper. The piezoelectric stack array 8 comprises three piezoelectric stacks distributed in an annular array. The three piezoelectric stacks form an annular array intelligent structure as a replacement for conventional single piezoelectric stack to effectively suppress micro-vibration signals that come from different directions and have multiple degrees of freedom.
Two spindle rods 2 are symmetrically arranged on two sides of the piezoelectric stack array 8, respectively, and are coaxially arranged to the central axis of the outer sleeve 9, with one end contacting against the first stop 7 and the other end extending out of the outer sleeve 9. One end of each spindle rod 2 is arranged to sequentially pass through the passive vibration isolation segment 3 and an end cover of the outer sleeve 9, and is then fixed to the connecting disc 1. The other end of the spindle rod 2 is an expanding connector, which comprises an expanding segment 22 and a body segment 21, wherein the diameter of the expanding segment 22 is greater than that of the body segment 21. The expanding segment 22 of the spindle rod is supported in the outer sleeve 9 by the linear bearing 6. Friction can be reduced by using the linear bearing, and thus the precision is improved.
A surface of the first stop 7 facing away from the piezoelectric stack array 8 is configured to have a concave arc shape, and one end of the expanding segment 22 of the spindle rod 2 is configured to have a convex arc shape that is associated with the concave arc shape. The first stop 7 is tangentially connected to one end of the spindle rod, which ensures the reliability of the piezoelectric stack and effectively prevents the piezoelectric stack from being damaged by shearing force.
The preloaded spring 5 is arranged outside the body segment 21 of the spindle rod 2, with one end of the preloaded spring 5 contacting against a platform that protrudes between the expanding segment 22 and the body segment 21 due to diameter change, and the other end contacting against the second stop 4. The expanding segment 22 of the spindle rod 2 can always be contacting against the active vibration isolation segment under the restoring force of the preloaded spring 5. Therefore, the piezoelectric stacks are firmly pre-pressed by using the preloaded spring to avoid sliding or loosening.
The spindle rod 2 is movably connected to the connecting disc 1, for example, by using a flexible hinge, which improves the sensitivity of the damper 10 responding to the frequency bandwidth and the displacement amplitude of micro-vibration, and thus the universality of the damper.
The passive vibration isolation segment 3, arranged between the body segment 21 and the outer sleeve 9, is a rubber damping module with one end thereof tightly contacting against an end cover of the outer sleeve 9, and the other end tightly contacting against the second stop 4 that is assembled in the outer sleeve.
The second stop 4 1s fixed to the outer sleeve 9 with screws. The connecting disc 1 is fixed to the spindle rod 2 with circumferentially and evenly distributed screws, and the periphery of the connecting disc 1 is evenly provided with threaded fasteners for connecting the upper platform and the lower platform. The upper and lower platforms are provided with connecting seats 12 for fixing the connecting disc 1. The connecting disc 1 is perpendicular to the spindle rod 2, and the surface of the connecting seats 12 is inclined at an angle that enables the damper 10 to meet the requirements of the above arrangement.
The internal structure of the damper is symmetrically arranged relative to the piezoelectric stack array 8, which allows for easy control, and eliminates the need to distinguish between the input end and the output end when the connecting rod is used, which allows for easy installation.
When the platform and the damper are used, the connecting discs at two ends are vibrated, such that when the spindle rod is displaced, the spindle rod is subject to the friction of the rubber damping module, and thus part of vibration signal displacement is offset, thereby achieving passive vibration isolation. Meanwhile the acceleration sensors arranged on the parallel platforms transmit a measured vibration signal to the industrial personal computer, the industrial personal computer outputs a control signal through the control algorithm to the controller designated for the piezoelectric stack according to the received vibration signal, the controller designated for the piezoelectric stack controls a driver designated for the piezoelectric stack according to the received control signal, the driver designated for the piezoelectric stack processes the received control signal and output a driving signal to the piezoelectric stack, and the piezoelectric stack converts the received electric signal into output displacement to drive the spindle rod. As such, the parallel platforms produce movement to offset micro-vibration, thereby achieving active vibration isolation. The micro-vibration can be suppressed through the above process.
The present invention further comprises a detection portion and a control portion. The detection portion comprises acceleration sensors, and the control portion comprises a piezoelectric stack driver, a piezoelectric stack controller and an industrial personal computer. Six of the eight dampers are moving rods for achieving six moving degrees of freedom of the upper platform, and the other two integrated active-passive dampers are redundant backup rods.
When one or two of the integrated active-passive dampers fail or the piezoelectric stacks are damaged, the redundant backup rods function to ensure the 6 moving degrees of freedom of the upper platform are retained, thereby ensuring the suppression of micro-vibration can be normally performed by the vibration suppression platform, and improving the reliability of performance.
The detecting portion comprises a number of acceleration sensors which is the same as that of the dampers. The acceleration sensors are arranged on a lower surface of the upper platform and are evenly distributed along a outer circumference of the upper platform; the acceleration sensors and the dampers are alternately arranged at one end of the upper platform, i.e., one acceleration sensor is arranged between two continuous dampers at one end of the upper platform. The acceleration sensors detect vibration signals, and the vibration signals are input into the industrial personal computer after being subject to denoising, amplification and other processes by a processor associated with the acceleration sensors.
The control portion comprises the driver designated for the piezoelectric stack, the controller designated for the piezoelectric stack and the industrial personal computer. The industrial personal computer outputs a control signal through the control algorithm to the controller designated for the piezoelectric stack according to the received vibration signal, the controller designated for the piezoelectric stack controls the driver designated for the piezoelectric stack according to the received control signal, and the driver designated for the piezoelectric stack processes the received control signal and output a driving signal to the piezoelectric stack array.
The control algorithm is a multi-objective fuzzy control algorithm, which takes the deviation and the deviation change rate between an actual position and an expected position of each piezoelectric stack as input, and takes an input voltage variation of the controller designated for the piezoelectric stack as output; the fuzzification process of each input and output is achieved by using a trapezoidal membership function; factor sets and evaluation sets are established, a single-factor fuzzy judgment matrix 1s established by mapping the factor sets to the evaluation sets, weight sets are established for the factor sets, fuzzy comprehensive evaluation sets are finally established, the fuzzy relationship between the fuzzy input and fuzzy output is thus established, and according to the fuzzy relationship, a fuzzy value for the output of the controller is given by fuzzy reasoning; the fuzzy value is then converted into a precise value by defuzzifier and output to the controller designated for the piezoelectric stack to achieve precise control of each piezoelectric stack.
As shown in FIG. 6, the same multi-objective fuzzy control algorithm is used for the two platforms. The same acceleration interference signal is introduced, and a displacement signal is obtained by integrating the acceleration signal twice. The acceleration signal and the displacement signal are then input into the dynamics model of the platform simultaneously, and the acceleration of the platform is output, displayed and fed back to the multi-objective fuzzy control model to finally complete the whole micro-vibration suppression process.
As shown in FIG. 7, under excitation of a translational interference signal, the maximum value of the acceleration interference signal is about 7 (as the accelerations in the figure are calculated by using relative values, there is no unit, and the same applies hereinafter). After suppression by the two platforms, the maximum value of the acceleration is about 1, suggesting a suppression of about 86%. Therefore, both the micro-vibration suppression platform of the parallel 8-connecting rod structure disclosed herein and the common micro-vibration suppression platform can suppress micro-vibration.
As shown in FIG. 8, under excitation of the translational interference signal, both the micro-vibration suppression platform of the parallel 8-connecting rod structure disclosed herein and the common micro-vibration suppression platform can suppress micro-vibration. In the detailed view of the comparison graph of the simulation results under excitation of a translational interference signal according to the present invention, it can be found that the micro-vibration suppression platform of the parallel 8-connecting rod structure disclosed herein has a better suppression effect.
As shown in FIG. 9, under excitation of a rotational interference signal, the maximum value of the acceleration interference signal is about 6.9. After suppression by the two platforms, the maximum value of the acceleration is about 0.9, suggesting a suppression of about 87%. Therefore, both the micro-vibration suppression platform of the parallel 8-connecting rod structure disclosed herein and the common micro-vibration suppression platform can suppress micro-vibration. 17900517 As shown in FIG. 10, under excitation of the rotational interference signal, both the micro-vibration suppression platform of the parallel 8-connecting rod structure disclosed herein and the common micro-vibration suppression platform can suppress micro-vibration.
In the detailed view of the comparison graph of the simulation results under excitation of a rotational interference signal according to the present invention, it can be found that the micro-vibration suppression platform of the parallel 8-connecting rod structure disclosed herein has a better suppression effect and a faster response.
Claims (10)
1. A micro-vibration suppression platform based on intelligent piezoelectric arrays, comprising an upper platform (11), a lower platform (13), and dampers (10) evenly distributed between the upper platform (11) and the lower platform (13) comprising primary dampers and secondary dampers, wherein the dampers (10) are inclined, and the primary dampers and the secondary dampers are alternately arranged; the damper (10) comprises an outer sleeve (9), a spindle rod (2) located in a central axis of the damper (10), and a piezoelectric stack array (8) arranged in the middle of the outer sleeve and provided with one spindle rod (2) at each of the two ends thereof, the piezoelectric stack array (8) comprises at least two piezoelectric stacks symmetrically distributed relative to the spindle rod (2), and the center of the array is hollow.
2. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 1, wherein a projection of the axis of the secondary damper on the lower platform is parallel to a projection of the axis of one adjacent primary damper on the lower platform, and is perpendicular to a projection of the axis of the other adjacent primary damper on a surface of the lower platform.
3. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 1, wherein between the two ends of the piezoelectric stack array (8) and one end of the spindle rod (2) is provided a first stop (7), and between the spindle rod (2) and the outer sleeve (9) is provided a linear bearing (6) and a second stop (4); the linear bearing (6) is arranged at the end of the spindle rod (2), the second stop is arranged in the middle of the spindle rod (2), and between the second stop (4) and the linear bearing (6) is provided a preloaded spring (5).
4. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 3, wherein the damper (10) comprises a passive vibration isolation segment (3) with one end contacting against one end of the outer sleeve (9) and the other end contacting against the second stop (4).
5. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 3, wherein a surface of the first block (7) facing away from the piezoelectric stack array (8) is provided with a concave arc, and one end of the spindle rod (2) is of a convex arc shape corresponding to the concave arc.
6. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 1, wherein the spindle rod (2) comprises an expanding segment (22) at one end and a body segment (21), the expanding segment (22) having a diameter greater than that of the body segment (21).
7. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 6 or 3, wherein the linear bearing (6) is arranged between the expanding segment (22) and the outer sleeve (9), and the preloaded spring (5) has one end contacting against a platform where the expanding section (22) protrudes.
8. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 1, wherein one end of the spindle rod (2) is arranged to extend out of the outer sleeve (9) and provided with a connecting disc (1); the upper platform and the lower platform are provided with connecting seats (12) for fixing the connecting discs (1); the connecting disc (1) is perpendicular to the spindle rod (2), and the surface of the connecting seat (12) is inclined.
9. The micro-vibration suppression platform based on the intelligent piezoelectric arrays according to claim 1 or 2, wherein a lower surface of the upper platform (11) is provided with a detection unit and a control unit; the detection unit comprises a number of acceleration sensors (14) corresponding to that of the dampers for detecting vibration signals; the control unit comprises a piezoelectric stack driver, a piezoelectric stack controller and an industrial personal computer; the industrial personal computer outputs a control signal according to the received vibration signal and an internal control algorithm to control the piezoelectric stack driver; the piezoelectric stack driver processes the received control signal and outputs a driving signal to drive the piezoelectric stack inside the moving rod to work.
10. A method for controlling a micro-vibration suppression platform based on intelligent piezoelectric arrays, wherein based on the micro-vibration suppression platform based on the intelligent piezoelectric arrays according to any one of claims 1-9, the method is based on a multi-objective fuzzy control algorithm, and specifically comprises the following steps: (1) taking the deviation and the deviation change rate between an actual position and an expected position of each piezoelectric stack as input, and taking an input voltage variation of the controller designated for the piezoelectric stack as output; (2) fuzzifying each input and output using a fuzzy-constrained trapezoidal membership function; establishing factor sets and evaluation sets, and establishing a single-factor fuzzy judgment matrix by mapping the factor sets to the evaluation sets; (3) establishing weight sets for the factor sets, and finally establishing fuzzy comprehensive evaluation sets, and thus the fuzzy relationship between the fuzzy input and output; (4) giving a fuzzy value for the output of the controller by fuzzy reasoning according to the fuzzy relationship; and (5) converting the fuzzy value into a precise value by defuzzifier and outputting the precise value to the controller designated for the piezoelectric stack to achieve precise control of each piezoelectric stack.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110053908.9A CN112923012B (en) | 2021-01-15 | 2021-01-15 | Micro-vibration suppression platform based on intelligent piezoelectric array and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| LU500517B1 true LU500517B1 (en) | 2022-02-07 |
Family
ID=76162954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| LU500517A LU500517B1 (en) | 2021-01-15 | 2021-08-06 | Micro-vibration suppression platform based on intelligent piezoelectric arrays and method for controlling same |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN112923012B (en) |
| LU (1) | LU500517B1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113356033A (en) * | 2021-07-02 | 2021-09-07 | 河南工业贸易职业学院 | Bridge anti-seismic system based on computer regulation and control |
| CN113686197A (en) * | 2021-08-30 | 2021-11-23 | 哈尔滨工业大学 | Gun vibration reduction system and method based on piezoelectric driver and gun equipment |
| CN116988730A (en) * | 2021-10-09 | 2023-11-03 | 何英姿 | Ground source heat pump building construction device based on power system noise reduction control |
| CN114215872B (en) * | 2021-12-17 | 2023-08-29 | 盐城工学院 | Active and passive integrated damper based on piezoelectric array and vibration isolation method |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6022005A (en) * | 1996-09-27 | 2000-02-08 | Trw Inc. | Semi-active vibration isolator and fine positioning mount |
| US5803213A (en) * | 1997-02-03 | 1998-09-08 | Honeywell Inc. | Heavy load vibration isolation apparatus |
| DE10358200B4 (en) * | 2003-12-12 | 2010-06-24 | Eurocopter Deutschland Gmbh | Rod-shaped, heavy duty, active connecting element and rotary wing aircraft with such a connecting element |
| US7950633B2 (en) * | 2008-08-07 | 2011-05-31 | Drs Rsta, Inc. | Vibration isolator system |
| CN101559833A (en) * | 2009-05-15 | 2009-10-21 | 江苏大学 | Passive vibration isolation device of main speed reduction box of helicopter |
| CN102155516B (en) * | 2011-01-24 | 2012-05-23 | 北京航空航天大学 | Eight-rod-redundant-configuration and six-degree-of-freedom active vibration control device |
| CN104344182B (en) * | 2014-09-12 | 2017-01-18 | 中国电子科技集团公司第三十八研究所 | Parallel mechanism vibration isolation and displacement protection device |
| CN106239274B (en) * | 2016-08-22 | 2018-06-05 | 天津理工大学 | A kind of multidimensional variable element vibrating machine burnishing device and its fuzzy PID control method |
| CN106286692B (en) * | 2016-09-20 | 2018-07-03 | 华中科技大学 | A kind of six degree of freedom micro-vibration inhibits platform and its control method |
| CN109204795B (en) * | 2017-07-05 | 2022-01-11 | 上海交通大学 | Eight-brace rod type multi-degree-of-freedom dynamic antiresonance vibration isolation device |
| CN109555812B (en) * | 2018-07-18 | 2023-04-28 | 中国航空工业集团公司洛阳电光设备研究所 | Piezoelectric-driven isotropic multi-degree-of-freedom vibration isolation platform |
-
2021
- 2021-01-15 CN CN202110053908.9A patent/CN112923012B/en active Active
- 2021-08-06 LU LU500517A patent/LU500517B1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| CN112923012B (en) | 2022-07-01 |
| CN112923012A (en) | 2021-06-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| LU500517B1 (en) | Micro-vibration suppression platform based on intelligent piezoelectric arrays and method for controlling same | |
| Schiavi et al. | VSA-II: A novel prototype of variable stiffness actuator for safe and performing robots interacting with humans | |
| CN113048173B (en) | Stewart vibration isolation platform of piezoelectric fiber sheet and control method thereof | |
| Aldraihem et al. | Distributed control of laminated beams: Timoshenko theory vs. Euler-Bernoulli theory | |
| US11085838B2 (en) | Force/torque sensor having serpentine or coiled deformable beams and overload beams | |
| WO1989008537A1 (en) | Articulatable structure with adjustable end-point compliance | |
| WO2020009961A1 (en) | Multi-axis force and torque sensor and robot having the same | |
| CN104613285A (en) | Large dynamic cubic Stewart active vibration control platform | |
| CN106286693A (en) | One is applicable to big amplitude and wide band active-passive integratedization subtracts isolation mounting | |
| Vischer et al. | Design and development of torque-controlled joints | |
| JP2019045216A (en) | Force sensor, torque sensor, force sensor, fingertip force sensor, and method for manufacturing the same | |
| CN107962591B (en) | Passive vibration-damping elastic element capable of measuring torque on flexible robot joint | |
| CN107989960B (en) | Metal rubber elastic element capable of measuring moment for flexible robot joint | |
| Wang et al. | A flat torsional spring with corrugated flexible units for series elastic actuators | |
| CN109555812B (en) | Piezoelectric-driven isotropic multi-degree-of-freedom vibration isolation platform | |
| JP2023534074A (en) | Multi-DOF Force/Torque Sensors and Robots | |
| CN114215872B (en) | Active and passive integrated damper based on piezoelectric array and vibration isolation method | |
| CN114952744B (en) | Voice coil motor direct-drive type active vibration isolation and leveling integrated platform | |
| CN116809976A (en) | Three-degree-of-freedom large-stroke fast cutter servo device and curved surface machining method thereof | |
| CN115157228A (en) | Gradient rigidity type flexible robot with self-locking mechanism | |
| CN208688700U (en) | A kind of series connection elastic mechanism with torgue measurement ability | |
| Anderson et al. | Hexapods for precision motion and vibration control | |
| CN110884695A (en) | High-precision vibration isolation satellite and control method thereof | |
| CN113954058B (en) | Flexible actuator, working method and robot | |
| CN117167433A (en) | Active and passive integrated vibration isolation mechanism based on electromagnetic damping and piezoelectric actuation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FG | Patent granted |
Effective date: 20220207 |