Parallel platform vibration suppression device and vibration suppression method

Abstract

The present invention relates to the field of vibration damping technology, and particularly to a vibration suppression device and method for a parallel platform. The vibration suppression method for a parallel platform is applied to the vibration suppression device for a parallel platform. The vibration suppression device for a parallel platform is arranged on the upper platform of the parallel platform, and the upper platform is used to place a load. The vibration suppression method includes determining the natural frequency corresponding to the load placed on the upper platform. According to the natural frequency corresponding to the load, a virtual vibration absorber is designed. The acceleration collected by the acceleration sensor of the inertial mass actuator is obtained and input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber. According to the control force generated by the virtual vibration absorber, the force output by the inertial mass actuator is determined. In this way, when the load mass changes and the natural frequency changes, the vibration suppression of the parallel platform at the natural frequency can be achieved without changing the mechanical structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of vibration reduction, and particularly relates to a vibration suppression device and a vibration suppression method for a parallel platform. Background Art

[0002] A parallel platform is such that an end effector with several degrees of freedom is connected to a fixed base through two or more kinematic chains. Due to its characteristics of high stiffness, high precision, and high load-carrying capacity, it has been widely applied. During the precise adjustment process of the parallel platform, especially in a space optical system or a high-precision positioning task, resonance at the natural frequency has a significant impact on the pointing accuracy. When the system performs a small adjustment or a rapid response, the inherent modes are easily excited, resulting in unwanted vibrations of the parallel platform. If the frequencies of these vibrations match the frequencies of external driving or disturbance signals, a resonance phenomenon will occur, thereby amplifying the vibration amplitude and affecting the pointing stability and pointing accuracy. Moreover, the change in the load mass has a direct impact on the natural frequency of the overall system formed by the parallel platform and the vibration suppression device of the parallel platform. An increase in the load usually leads to a decrease in the natural frequency of the parallel platform, while a decrease in the load may lead to an increase in the natural frequency of the parallel platform. This makes it easier to enter the resonance state under conditions of different load masses, especially during high-frequency operations, resulting in a significant decrease in the accuracy of the parallel platform. Therefore, effective vibration suppression and control strategies must be adopted.

[0003] Active vibration isolation technology can effectively suppress the excitation of inherent modes and avoid resonance by monitoring and adjusting the vibration response of the system in real time. Passive vibration absorber technology can adjust the damping and stiffness of the system to precisely control the vibration mode and ensure that the natural frequency does not have a negative impact on the system. However, passive vibration absorbers cannot adjust their own frequencies, so active control cannot be achieved. The existing vibration suppression technologies for parallel platforms include passive vibration absorber technology and active vibration isolation technology, which have some significant drawbacks and deficiencies. Passive vibration absorber technology relies on adding physical vibration absorbers to reduce vibration. Although it can play a certain inhibitory role within a certain frequency range, the control effect on the modes of the overall system is poor, and it cannot cope with changes in the natural frequency of the overall system. Due to the poor adaptability of passive vibration absorbers to load changes and their inability to dynamically adjust their parameters according to load changes, the system is prone to enter the resonance state when the load fluctuates, which in turn affects the accuracy and stability of the platform. Although active vibration isolation technology improves vibration suppression by monitoring and controlling vibration in real time, it usually assumes that the load remains constant and lacks the ability to adapt to load changes in real time. When the load changes significantly, fluctuations in the natural frequency may cause the control strategy to fail, thereby affecting the vibration suppression effect and unable to ensure that the system is always in the optimal control state. In addition, the existing methods for adjusting the natural frequency usually rely on static optimization and cannot respond in real time to changes in the dynamic environment, especially when the load fluctuates greatly, it is difficult to effectively avoid fluctuations in the natural frequency and resonance phenomena. Most importantly, the existing technologies have deficiencies in the control of system modes. The inhibitory force of traditional vibration control systems on system modes is limited. Especially during precise adjustment and rapid response processes, vibration may cause a significant reduction in the accuracy and stability of the system. Therefore, the existing passive vibration absorber and active vibration isolation technologies cannot effectively ensure the stability and pointing accuracy of the system when facing a complex dynamic load environment, which limits their application in the field of high-precision control.

[0004] The invention patent application with the Chinese patent publication number CN105252539A, publication date January 20, 2016, and patent name "A vibration control system and method for suppressing the vibration of a parallel platform based on an acceleration sensor". It discloses a vibration control system and method for suppressing the vibration of a parallel platform based on an acceleration sensor, including three parallel branches. Each parallel branch includes a three-phase AC servo motor, a reducer, an active rod, and a passive rod. The three-phase AC servo motors are installed on the fixed platform and are distributed in an equilateral triangle. The three-phase AC servo motors are connected to the reducer. The reducer is connected to the active rod through a rotating shaft. The other end of the active rod is connected to the driven rod through a rotating shaft. The other end of the driven rod is connected to the moving platform through a rotating shaft. The moving platform is in the shape of an equilateral triangle. An incremental encoder is used to measure the position of the active joint, and an acceleration sensor is used to detect the accelerations of the moving platform and the active rod of the parallel platform. A controller is designed comprehensively based on the active joint position information and acceleration information to suppress the vibration during the movement of the parallel platform or the self-excited vibration during point positioning. Usually, it combines sensor feedback with an optimization algorithm to adjust the control parameters in real time, but its implementation complexity is relatively high, and there are still certain challenges in the precise control of vibration suppression at the natural frequency. Summary of the Invention

[0005] In view of this, the present invention aims to provide a vibration suppression device and a vibration suppression method for a parallel platform, which can achieve vibration suppression of the parallel platform at the natural frequency without changing the mechanical structure when the natural frequency changes due to the change of the load mass.

[0006] To achieve the above object, the technical solution of the present invention is realized as follows:

[0007] A vibration suppression method for a parallel platform, which is applied to a vibration suppression device for a parallel platform. The vibration suppression device for a parallel platform is arranged on the upper platform of the parallel platform, and the upper platform is used to place a load. The vibration suppression device for a parallel platform includes a controller and three inertial mass actuators. The three inertial mass actuators are respectively arranged along three orthogonal directions and are used to output forces in three orthogonal directions. The inertial mass actuator includes an acceleration sensor. The controller is used to execute the vibration suppression method. The vibration suppression method includes:

[0008] Determine the natural frequency corresponding to the upper platform and the load placed thereon;

[0009] Design a virtual absorber according to the natural frequency;

[0010] Obtain the acceleration collected by the acceleration sensor of the inertial mass actuator and input it into the virtual absorber to determine the control force generated by the virtual absorber;

[0011] Determine the force output by the inertial mass actuator according to the control force generated by the virtual absorber.

[0012] Furthermore, according to the natural frequency, a virtual vibration absorber is designed, including:

[0013] The stiffness and mass parameters of the virtual vibration absorber are determined by the following formula:

[0014]

[0015] Where, is the stiffness of the virtual vibration absorber, is the mass parameter of the virtual vibration absorber, is the natural frequency.

[0016] Furthermore, according to the natural frequency, the design of the virtual vibration absorber also includes:

[0017] The damping of the virtual vibration absorber is determined by the following formula:

[0018]

[0019] Where, is the damping of the virtual vibration absorber.

[0020] Furthermore, the acceleration collected by the acceleration sensor of the inertial mass actuator is obtained and input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber, including:

[0021] The control force generated by the virtual vibration absorber is determined by the following formula:

[0022]

[0023] Where, is the control force generated by the virtual vibration absorber, is the control gain, is the stiffness of the virtual vibration absorber, is the mass parameter of the virtual vibration absorber, is the damping of the virtual vibration absorber, is the complex frequency variable in the Laplace transform, is the acceleration collected by the acceleration sensor.

[0024] Furthermore, the parallel platform vibration suppression device includes a band-pass filter and a notch filter; the acceleration collected by the acceleration sensor of the inertial mass actuator is obtained and input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber, including:

[0025] The acceleration collected by the acceleration sensor of the inertial mass actuator is filtered by the band-pass filter and the notch filter and then input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber.

[0026] Further, before obtaining the acceleration collected by the acceleration sensor of the inertial mass actuator and inputting it into the virtual absorber after filtering by a band-pass filter and a notch filter to determine the control force generated by the virtual absorber, the vibration suppression method further includes:

[0027] According to the natural frequency, adjust the working bandwidth of the band-pass filter and the working bandwidth of the notch filter so that the natural frequency is within the working bandwidth of the band-pass filter and the working bandwidth of the notch filter.

[0028] Further, adjusting the working bandwidth of the band-pass filter according to the natural frequency includes:

[0029] According to the natural frequency, adjust the center frequency of the band-pass filter and its corresponding first quality factor, and adjust the working bandwidth of the band-pass filter through the transfer function of the band-pass filter;

[0030] The transfer function of the band-pass filter is as follows:

[0031]

[0032] where is the center frequency of the band-pass filter, is the first quality factor, is the complex frequency variable in the Laplace transform.

[0033] Further, adjusting the working bandwidth of the notch filter according to the natural frequency includes:

[0034] According to the natural frequency, adjust the center frequency of the notch filter and its corresponding second quality factor, and adjust the working bandwidth of the notch filter through the transfer function of the notch filter;

[0035] The transfer function of the notch filter is as follows:

[0036]

[0037] where is the center frequency of the notch filter, is the second quality factor, is the complex frequency variable in the Laplace transform.

[0038] A parallel platform vibration suppression device for performing the parallel platform vibration suppression method as described above.

[0039] Furthermore, the inertial mass actuator includes a mounting bracket, an inertial mass block, a voice coil motor, and an elastic member; the inertial mass block is located within the mounting bracket, and the side wall of the inertial mass block is connected to the inner wall of the mounting bracket through the elastic member; the stator of the voice coil motor is connected to the mounting bracket, and the mover of the voice coil motor is connected to the inertial mass block. The voice coil motor is used to drive the inertial mass block to move, so as to act on the upper platform through the elastic member and the mounting bracket; and / or

[0040] The inertial mass actuator includes an acceleration sensor and a mounting plate. The inertial mass actuator is fixed to the upper platform through the mounting plate; the acceleration sensor is disposed on the mounting plate and is used to acquire an acceleration signal.

[0041] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0042] For the parallel platform vibration suppression method described in the present invention, a virtual absorber is adopted. Compared with traditional physical absorbers or vibration isolators, the control parameters of the overall system can be adjusted through software. When the mass of the load changes, causing the natural frequency to change, without changing the structure of the overall system, only the parameters of the virtual absorber need to be adjusted to achieve dynamic adjustment corresponding to the change in the mass of the load, thereby ensuring the stability of the overall system and effectively suppressing the vibration of the parallel platform at the natural frequency, and reducing the high complexity and cost caused by the need to change the mechanical structure of the passive absorber when the natural frequency changes. At the same time, the virtual absorber uses an inertial mass actuator to achieve power output to achieve the effect of the absorber, without adding additional hardware structures, making the structure of the parallel platform vibration suppression device simpler and lighter, with a small additional mass of the parallel platform and not changing the dynamic characteristics of the overall system. And the virtual absorber simulates the function of the absorber through the inertial mass actuator combined with software-level control, and can be more conveniently integrated into the overall system, and can be adapted to various occasions, especially occasions where it is not desired to make too many changes to the existing design. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0044] Figure 1 is a schematic diagram of the parallel platform described in the embodiment of the present invention;

[0045] Figure 2 is a schematic diagram of the parallel platform vibration suppression device described in the embodiment of the present invention;

[0046] Figure 3 is a schematic diagram of the inertial mass actuator described in the embodiment of the present invention;

[0047] Figure 4 It is a flowchart of the vibration suppression method for the parallel platform according to the embodiment of the present invention.

[0048] Explanation of reference numerals:

[0049] Vibration suppression device 10 for the parallel platform; parallel platform 11; upper platform 12; lower platform 13; leg 14; load 15; inertial mass actuator 16; first inertial mass actuator 17; second inertial mass actuator 18; third inertial mass actuator 19; mounting bracket 20; inertial mass block 21; voice coil motor 22; elastic member 23; acceleration sensor 24; mounting plate 25. Detailed implementation manners

[0050] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many details are described to enable a better understanding of the present invention. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present invention are not shown or described in the specification, in order to avoid the core part of the present invention being overwhelmed by excessive description. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0051] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other to form various embodiments. At the same time, the steps or actions in the method description can also be adjusted in the order that is obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment, and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0053] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0054] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0055] See Figure 1 and Figure 2 As shown in, an embodiment of the present invention provides a parallel platform vibration suppression device 10, which can be used to achieve the vibration suppression of the parallel platform 11. The parallel platform 11 may include an upper platform 12, a lower platform 13, and a plurality of legs 14 connected between the upper platform 12 and the lower platform 13. The upper platform 12 is used to place a load 15. The parallel platform vibration suppression device 10 is disposed on the upper platform 12 of the parallel platform 11. The parallel platform vibration suppression device 10 includes a controller (not shown in the figure), and the controller is used to execute the parallel platform vibration suppression method.

[0056] The parallel platform vibration suppression device 10 includes three inertial mass actuators, which are respectively arranged along three orthogonal directions and are used to output forces in three orthogonal directions. That is, the three directions include a first direction X, a second direction Y, and a third direction Z that are perpendicular to each other. The three inertial mass actuators include a first inertial mass actuator 17, a second inertial mass actuator 18, and a third inertial mass actuator 19. Among them, the first inertial mass actuator 17 is arranged along the first direction X, the second inertial mass actuator 18 is arranged along the second direction Y, and the third inertial mass actuator 19 is arranged along the third direction Z. By the orthogonal combination of the three inertial mass actuators, vibration suppression at the natural frequencies of multiple degrees of freedom of the parallel platform can be achieved.

[0057] See Figure 3 As shown, in one embodiment, the inertial mass actuator 16 includes a mounting bracket 20, an inertial mass block 21, a voice coil motor 22, and an elastic member 23. The elastic member 23 can be a spring plate. The inertial mass block 21 is located within the mounting bracket 20, and the side wall of the inertial mass block 21 is connected to the inner wall of the mounting bracket 20 through the elastic member 23. The stator of the voice coil motor 22 is connected to the mounting bracket 20, and the mover of the voice coil motor 22 is connected to the inertial mass block 21. The voice coil motor 22 is used to drive the inertial mass block 21 to move, so as to act on the upper platform 12 through the elastic member 23 and the mounting bracket 20.

[0058] In one embodiment, the inertial mass actuator 16 includes an acceleration sensor 24 and a mounting plate 25, and the inertial mass actuator 16 is fixed to the upper platform 12 through the mounting plate 25. In Figure 1 In the shown embodiment, the three inertial mass actuators 16 can be fixed to the conversion structure through the same mounting plate 25 and fixed to the upper platform 12 through the conversion structure. Each of the three inertial mass actuators 16 is correspondingly provided with an acceleration sensor 24. Among them, the stator of the voice coil motor 22 can be connected to one side surface of the mounting plate 25 through the mounting bracket 20. The acceleration sensor 24 is arranged on the mounting plate 25 and is used to obtain an acceleration signal. The acceleration sensor 24 can be arranged on one side surface of the mounting plate 25.

[0059] See Figure 1 、 Figure 3 and Figure 4 As shown, an embodiment of the present invention provides a parallel platform vibration suppression method, which is applied to the parallel platform vibration suppression device 10. The vibration suppression method includes steps S101 to S104.

[0060] In step S101, the natural frequency corresponding to the upper platform 12 and the load 15 placed thereon is determined. When the parallel platform 11 and all the legs 14 are operating normally and in a stable working state, the acceleration sensor 24 integrated in the inertial mass actuator 16 can be used for testing to determine the natural frequency corresponding to the upper platform 12 and the load 15 placed thereon. Specifically, the natural frequency can be determined by analyzing the acceleration spectrum based on the acceleration collected by the acceleration sensor 24 of the inertial mass actuator 16. When the mass of the load 15 placed on the upper platform 12 changes, it is necessary to retest to determine the natural frequency, so as to facilitate the subsequent design of the virtual vibration absorber.

[0061] In step S102, a virtual vibration absorber is designed according to the natural frequency.

[0062] In one embodiment, step S102 includes determining the stiffness and mass parameters of the virtual vibration absorber through the following formula:

[0063]

[0064] Wherein, is the stiffness of the virtual vibration absorber, is the mass of the virtual vibration absorber, is the natural frequency.

[0065] In one embodiment, step S102 further includes determining the damping of the virtual vibration absorber through the following formula:

[0066]

[0067] Wherein, is the damping of the virtual vibration absorber. Thus, the stiffness, mass and damping of the virtual vibration absorber can be determined respectively according to the natural frequency through the above formulas.

[0068] In step S103, the acceleration collected by the acceleration sensor 24 of the inertial mass actuator 16 is obtained and input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber.

[0069] In one embodiment, step S103 includes determining the control force generated by the virtual vibration absorber through the following formula:

[0070]

[0071] Wherein, is the control force generated by the virtual vibration absorber, is the control gain, is the complex frequency variable in the Laplace transform, is the acceleration collected by the acceleration sensor. The control gain The action intensity of the virtual vibration absorber can be controlled, and the control gain can be selected according to the actual situation. In this way, the acceleration collected by the acceleration sensor can be combined with the virtual vibration absorber, so as to adjust the vibration mode of the overall system formed by the parallel platform 11 and the parallel platform vibration suppression device 10, and suppress the vibration of the parallel platform 11 at the natural frequency.

[0072] In step S104, according to the control force generated by the virtual vibration absorber, the force output by the inertial mass actuator 16 is determined. In this way, the acceleration of each inertial mass actuator 16 can be input respectively to obtain the force output by each inertial mass actuator 16. The three inertial mass actuators 16 are respectively arranged along three orthogonal directions and can output forces in three orthogonal directions, so as to better suppress the vibration of the parallel platform 10.

[0073] The present invention adopts a virtual vibration absorber. Compared with traditional physical vibration absorbers or vibration isolators, the control parameters of the overall system can be adjusted through software. When the mass of the load 15 changes and the natural frequency changes, it is not necessary to change the structure of the overall system, but only to adjust the parameters of the virtual vibration absorber, so as to achieve dynamic adjustment corresponding to the mass change of the load 15, thus ensuring the stability of the overall system and effectively suppressing the vibration of the parallel platform 11 at the natural frequency, and reducing the high complexity and cost caused by changing the mechanical structure of the passive vibration absorber when the natural frequency changes.

[0074] At the same time, the virtual vibration absorber uses the inertial mass actuator 16 to achieve power output to achieve the effect of the vibration absorber, without adding additional hardware structure, making the structure of the parallel platform vibration suppression device 10 simpler and lighter, and the additional mass of the parallel platform 11 is small, without changing the dynamic characteristics of the overall system. And the virtual vibration absorber simulates the action of the vibration absorber through the inertial mass actuator 16 combined with software-level control, and can be more conveniently integrated into the overall system, and can be adapted to a variety of occasions, especially occasions where it is not desired to make too many changes to the existing design.

[0075] Among them, the controller can adopt a PLC, and the control system of the parallel platform vibration suppression device 10 can include a controller, a signal collector, a linear power amplifier and a signal output terminal. The acceleration can be measured by the acceleration sensor 24, transmitted to the signal acquisition terminal for acquisition, and the control instruction is transmitted to the output terminal. The control signal can be output through the linear power amplifier and drive the inertial mass actuator 16 to apply force. This method can not only effectively suppress the vibration at the natural frequency, but also adapt to the change of the load and the natural frequency of the overall system through the dynamic adjustment of the virtual vibration absorber, so as to ensure the accuracy and stability of the overall system.

[0076] In one embodiment, the parallel platform vibration suppression device 10 includes a band-pass filter and a notch filter. Step S103 includes obtaining the acceleration collected by the acceleration sensor 24 of the inertial mass actuator 16, filtering it through the band-pass filter and the notch filter, and inputting it into the virtual absorber to determine the control force generated by the virtual absorber. Setting the band-pass filter and the notch filter can avoid the interference of system high-frequency noise and integral saturation. It can filter out the noise of the acceleration collected by the acceleration sensor 24.

[0077] In one embodiment, before obtaining the acceleration collected by the acceleration sensor 24 of the inertial mass actuator 16, filtering it through the band-pass filter and the notch filter, and inputting it into the virtual absorber to determine the control force generated by the virtual absorber, the vibration suppression method further includes: according to the natural frequency, adjusting the working bandwidth of the band-pass filter and the working bandwidth of the notch filter so that the natural frequency is within the working bandwidth of the band-pass filter and the working bandwidth of the notch filter.

[0078] In one embodiment, adjusting the working bandwidth of the band-pass filter according to the natural frequency includes: according to the natural frequency, adjusting the center frequency of the band-pass filter and its corresponding first quality factor, and adjusting the working bandwidth of the band-pass filter through the transfer function of the band-pass filter.

[0079] The transfer function of the band-pass filter is as follows:

[0080]

[0081] where, is the center frequency of the band-pass filter, is the first quality factor. The center frequency of the band-pass filter is usually selected as the natural frequency of the overall system or the intermediate frequency of the main frequency band of concern. The first quality factor can determine the band-pass width. In this way, the low-frequency signal can be removed through the band-pass filter, reducing the system instability caused by the accumulation of integral errors. In addition, the high-frequency signal can be filtered out, reducing the influence of the high-frequency mode of the parallel platform on the control system of the parallel platform vibration suppression device 10.

[0082] In one embodiment, adjusting the working bandwidth of the notch filter according to the natural frequency includes: according to the natural frequency, adjusting the center frequency of the notch filter and its corresponding second quality factor, and adjusting the working bandwidth of the notch filter through the transfer function of the notch filter.

[0083] The transfer function of the notch filter is as follows:

[0084]

[0085] Among them, is the center frequency of the notch filter, is the second quality factor. The center frequency of the notch filter is usually selected as the natural frequency of the overall system or the frequency at which the vibration peak occurs. The second quality factor can determine the notch width. Thus, by adjusting the center frequency and bandwidth of the notch filter, the resonance response of the parallel platform 11 at the natural frequency can be precisely suppressed, thereby reducing the impact of the vibration caused by resonance on the overall system.

[0086] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added, or deleted. For example, the steps recited in the disclosure of the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and no limitation is imposed herein.

[0087] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A vibration suppression method for a parallel platform, characterized in that, Applied to a parallel platform vibration suppression device, the parallel platform includes an upper platform, a lower platform, and a plurality of legs connecting the upper platform and the lower platform. The parallel platform vibration suppression device is disposed on the upper platform of the parallel platform, and the upper platform is used to place a load; the parallel platform vibration suppression device includes a controller, three inertial mass actuators, a band-pass filter, and a notch filter. The three inertial mass actuators are respectively arranged along three orthogonal directions and are used to output forces in three orthogonal directions. The inertial mass actuator includes an acceleration sensor; the controller is used to execute the vibration suppression method; the vibration suppression method includes: Determine the natural frequency corresponding to the upper platform and the load placed thereon, including determining the natural frequency by analyzing the acceleration spectrum based on the acceleration collected by the acceleration sensor; Design a virtual absorber according to the natural frequency, including: Determine the stiffness and mass parameters of the virtual absorber through the following formula: Among them, is the stiffness of the virtual vibration absorber, is the mass parameter of the virtual vibration absorber, is the natural frequency; Obtain the acceleration collected by the acceleration sensor of the inertial mass actuator and input it into the virtual absorber to determine the control force generated by the virtual absorber, including: Adjust the working bandwidth of the band-pass filter and the working bandwidth of the notch filter according to the natural frequency so that the natural frequency is within the working bandwidth of the band-pass filter and the working bandwidth of the notch filter; Obtain the acceleration collected by the acceleration sensor of the inertial mass actuator, filter it through the band-pass filter and the notch filter, input it into the virtual absorber, and determine the control force generated by the virtual absorber through the following formula: Among them, is the control force generated by the virtual vibration absorber, is the control gain, is the damping of the virtual vibration absorber, is the complex frequency variable in the Laplace transform, is the acceleration collected by the acceleration sensor; Determine the force output by the inertial mass actuator according to the control force generated by the virtual absorber.

2. The vibration suppression method of the parallel platform according to claim 1, wherein The design of the virtual absorber according to the natural frequency further includes: Determine the damping of the virtual absorber through the following formula: Among them, is the damping of the virtual vibration absorber.

3. The vibration suppression method for the parallel platform according to claim 1, wherein The adjustment of the working bandwidth of the band-pass filter according to the natural frequency includes: Adjust the center frequency and the corresponding first quality factor of the band-pass filter according to the natural frequency, and adjust the working bandwidth of the band-pass filter through the transfer function of the band-pass filter; Transfer function of the band-pass filter The formula is as follows: Among them, is the center frequency of the band-pass filter, is the first quality factor, is the complex frequency variable in the Laplace transform.

4. The vibration suppression method for the parallel platform according to claim 1, wherein The adjustment of the working bandwidth of the notch filter according to the natural frequency includes: Adjust the center frequency and the corresponding second quality factor of the notch filter according to the natural frequency, and adjust the working bandwidth of the notch filter through the transfer function of the notch filter; The transfer function of the notch filter is given by the following formula: Among them, is the center frequency of the notch filter, is the second quality factor, is the complex frequency variable in the Laplace transform.

5. A vibration suppression device for a parallel platform, characterized in that, For executing the parallel platform vibration suppression method according to any one of claims 1-4.

6. The vibration suppression device for a parallel platform according to claim 5, characterized in that, The inertial mass actuator includes a mounting bracket, an inertial mass block, a voice coil motor, and an elastic member; the inertial mass block is located within the mounting bracket, and the side wall of the inertial mass block is connected to the inner wall of the mounting bracket through the elastic member; the stator of the voice coil motor is connected to the mounting bracket, and the mover of the voice coil motor is connected to the inertial mass block. The voice coil motor is used to drive the inertial mass block to move so as to act on the upper platform through the elastic member and the mounting bracket; and / or The inertial mass actuator includes an acceleration sensor and a mounting plate. The inertial mass actuator is fixed to the upper platform through the mounting plate. The acceleration sensor is arranged on the mounting plate and is used to acquire acceleration signals.

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