Parallel platform vibration suppression device and vibration suppression method

Abstract

The invention relates to the technical field of vibration reduction, in particular to a parallel platform vibration suppression device and a vibration suppression method. The parallel platform vibration suppression method is applied to the parallel platform vibration suppression device, the parallel platform vibration suppression device is arranged on an upper platform of a parallel platform, and the upper platform is used for placing a load. The vibration suppression method includes determining an inherent frequency corresponding to a load placed on an upper platform. And according to the inherent frequency corresponding to the load, a virtual vibration absorber is designed. And acquiring the acceleration acquired by an acceleration sensor of the inertial mass actuator, and inputting the acceleration 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. Therefore, under the condition that the inherent frequency is changed due to the change of the load mass, the vibration suppression of the parallel platform at the inherent frequency can be realized without changing the mechanical structure.

Description

Technical Field

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

[0002] The parallel platform is an end effector with several degrees of freedom connected to a fixed base through two or more kinematic branches. It has been widely used due to its high stiffness, high precision and high load-bearing capacity. In the precision adjustment process of the parallel platform, especially in space optical systems or high-precision positioning tasks, the resonance at the natural frequency has a significant impact on the pointing accuracy. When the system performs small adjustments or fast responses, the natural mode is easily excited, causing the parallel platform to produce undesirable vibrations. If these vibration frequencies match the frequencies of external drive or disturbance signals, resonance will occur, thereby amplifying the vibration amplitude and affecting the pointing stability and pointing accuracy. And the change in load mass has a direct impact on the natural frequency of the overall system formed by the parallel platform and the parallel platform vibration suppression device. An increase in load usually leads to a decrease in the natural frequency of the parallel platform, while a decrease in load may lead to an increase in the natural frequency of the parallel platform. This makes it easier to enter the resonance state under the conditions of different load masses, especially when operating at high frequencies, 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 natural modes and avoid resonance by real-time monitoring and adjusting the vibration response of the system. Passive vibration absorber technology can adjust the damping and stiffness of the system, accurately 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. Existing vibration suppression technologies for parallel platforms include passive vibration absorber technology and active vibration isolation technology, which have some significant shortcomings and deficiencies. Passive vibration absorber technology relies on adding physical vibration absorbers to slow down vibration. Although it can play a certain inhibitory role within a certain frequency range, it has poor control effect on the mode of the overall system and cannot cope with changes in the natural frequency of the overall system. Due to the poor adaptability of passive vibration absorbers to load changes, their parameters cannot be dynamically adjusted according to changes in load, which causes the system to easily enter a resonant state when the load fluctuates, thereby affecting the accuracy and stability of the platform. Although active vibration isolation technology improves vibration suppression by real-time monitoring and control of vibration, 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, the fluctuation of the natural frequency may cause the control strategy to fail, thereby affecting the vibration suppression effect and making it impossible to ensure that the system is always in the optimal control state. In addition, the existing natural frequency adjustment methods usually rely on static optimization and cannot respond to changes in the dynamic environment in real time, especially when the load fluctuates greatly. It is difficult to effectively avoid the fluctuation and resonance of the natural frequency. Most importantly, the existing technology has deficiencies in the control of system modes. The traditional vibration control system has limited suppression of system modes. Especially in the process of precise adjustment and rapid response, vibration may cause the accuracy and stability of the system to be greatly reduced. Therefore, the existing passive vibration absorbers and active vibration isolation technologies cannot effectively guarantee the stability and pointing accuracy of the system when facing complex dynamic load environments, which limits their application in the field of high-precision control.

[0004] The Chinese patent publication number is CN105252539A, the publication date is January 20, 2016, and the patent name is "A control system and method for suppressing the vibration of a parallel platform based on an acceleration sensor". It discloses a control system and method for suppressing the vibration of a parallel platform based on an acceleration sensor, including three parallel branches, each of which includes a three-phase AC servo motor, a reducer, an active rod, and a passive rod. The three-phase AC servo motor is installed on a fixed platform and distributed in an equilateral triangle. The three-phase AC servo motor is connected to the reducer, and 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, and the other end of the driven rod is connected to the moving platform through a rotating shaft. The moving platform is an equilateral triangle. An incremental encoder is used to test the active joint position, and an acceleration sensor is used to detect the acceleration of the parallel platform moving platform and the active rod. The controller is designed based on the active joint position information and acceleration information to suppress the vibration of the parallel platform during movement or the self-excited vibration during point positioning. Usually, sensor feedback and optimization algorithms are combined to adjust control parameters in real time, but its implementation is relatively complex 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 parallel platform vibration suppression device and a vibration suppression method, which can achieve vibration suppression of the parallel platform at the natural frequency without changing the mechanical structure when the load mass changes and the natural frequency changes.

[0006] To achieve the above object, the technical solution created by the present invention is implemented as follows: A parallel platform vibration suppression method is applied to a parallel platform vibration suppression device, wherein the parallel platform vibration suppression device is arranged on an upper platform of the parallel platform, and the upper platform is used to place a load; the parallel platform vibration suppression device comprises a controller and three inertial mass actuators, wherein the three inertial mass actuators are arranged in three orthogonal directions respectively and are used to output forces in the three orthogonal directions, and the inertial mass actuators comprise acceleration sensors; the controller is used to execute the vibration suppression method; the vibration suppression method comprises: Determine the natural frequencies corresponding to the upper platform and the load placed on it; Design virtual vibration absorber according to natural frequency; Acquire the acceleration collected by the acceleration sensor of the inertial mass actuator and input it into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber; Based on the control force generated by the virtual vibration absorber, the force output by the inertial mass actuator is determined.

[0007] Furthermore, according to the natural frequency, a virtual vibration absorber is designed, including: The stiffness and mass parameters of the virtual vibration absorber are determined by the following formula:

[0008] in, is the stiffness of the virtual vibration absorber, is the mass parameter of the virtual vibration absorber, is the natural frequency.

[0009] Furthermore, according to the natural frequency, a virtual vibration absorber is designed, which also includes: The damping of the virtual vibration absorber is determined by the following formula:

[0010] in, is the damping of the virtual shock absorber.

[0011] 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: The control force generated by the virtual vibration absorber is determined by the following formula:

[0012] in, The control force generated by the virtual vibration absorber, To control the gain, is the stiffness of the virtual vibration absorber, is the mass parameter of the virtual vibration absorber, is the damping of the virtual shock absorber, is the complex frequency variable in the Laplace transform, It is the acceleration collected by the acceleration sensor.

[0013] Furthermore, the parallel platform vibration suppression device includes a bandpass 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: The acceleration collected by the acceleration sensor of the inertial mass actuator is obtained, filtered through a bandpass filter and a notch filter, and then input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber.

[0014] Furthermore, before obtaining the acceleration collected by the acceleration sensor of the inertial mass actuator, filtering it through a bandpass filter and a notch filter, and inputting it into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber, the vibration suppression method also includes: According to the natural frequency, the working bandwidth of the bandpass filter and the working bandwidth of the notch filter are adjusted so that the natural frequency is within the working bandwidth of the bandpass filter and the working bandwidth of the notch filter.

[0015] Furthermore, the working bandwidth of the bandpass filter is adjusted according to the natural frequency, including: According to the natural frequency, the center frequency of the bandpass filter and the first quality factor corresponding thereto are adjusted, and the working bandwidth of the bandpass filter is adjusted through the transfer function of the bandpass filter; Transfer Function of a Bandpass Filter The formula is as follows:

[0016] in, is the center frequency of the bandpass filter, is the first quality factor, is the complex frequency variable in the Laplace transform.

[0017] Furthermore, the working bandwidth of the notch filter is adjusted according to the natural frequency, including: According to the natural frequency, the center frequency of the notch filter and its corresponding second quality factor are adjusted, and the working bandwidth of the notch filter is adjusted through the transfer function of the notch filter; Transfer Function of Notch Filter The formula is as follows:

[0018] in, is the center frequency of the notch filter, is the second quality factor, is the complex frequency variable in the Laplace transform.

[0019] A parallel platform vibration suppression device is used to execute the parallel platform vibration suppression method as described above.

[0020] Further, 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 in 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, the mover of the voice coil motor is connected to the inertial mass block, and 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 comprises 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 obtain an acceleration signal.

[0021] Compared with the prior art, the invention can achieve the following beneficial effects: The parallel platform vibration suppression method created by the present invention adopts a virtual vibration absorber. Compared with the traditional physical vibration absorber or vibration isolator, the control parameters of the overall system can be adjusted by software. When the mass change of the load causes the natural frequency to change, there is no need to change the structure of the overall system, and only the parameters of the virtual vibration absorber need to be adjusted to achieve dynamic adjustment corresponding to the mass change of the load, thereby ensuring the stability of the overall system and effectively suppressing the vibration of the parallel platform at the natural frequency, reducing the high complexity and cost caused by the need to change the mechanical structure of the passive vibration absorber when the natural frequency changes. At the same time, the virtual vibration absorber uses an inertial mass actuator 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 simpler and lighter, and the additional mass of the parallel platform is small, which will not change the dynamic characteristics of the overall system. And the virtual vibration absorber can be more conveniently integrated into the overall system by using an inertial mass actuator with software-level control to simulate the effect of the vibration absorber, and can be adapted to a variety of occasions, especially to occasions where it is not desired to make too many changes to the existing design. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 A schematic diagram of a parallel platform according to an embodiment of the present invention; Figure 2 A schematic diagram of a parallel platform vibration suppression device according to an embodiment of the present invention; Figure 3 A schematic diagram of an inertial mass actuator according to an embodiment of the present invention; Figure 4 The present invention is a flowchart of a parallel platform vibration suppression method according to an embodiment of the present invention.

[0023] Description of reference numerals: Parallel platform vibration suppression device 10; parallel platform 11; upper platform 12; lower platform 13; support 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 DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the invention clearer, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the invention and do not constitute a limitation to the invention. Similar components in different embodiments use associated similar component numbers. In the following embodiments, many detailed descriptions are to enable the invention to be better understood. 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 components, materials, and methods. In some cases, some operations related to the invention are not shown or described in the specification, in order to avoid the core part of the invention being overwhelmed by too much description, and 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 according to the description in the specification and the general technical knowledge in the art.

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to form various implementation methods. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary sequence, unless otherwise specified that a certain sequence must be followed.

[0026] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the 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 therefore cannot be understood as a limitation on the 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 indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0027] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0029] See also Figure 1 and Figure 2 As shown, the embodiment of the invention provides a parallel platform vibration suppression device 10, which can be used to achieve vibration suppression of a 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, and the upper platform 12 is used to place a load 15. The parallel platform vibration suppression device 10 is arranged 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), which is used to execute the parallel platform vibration suppression method.

[0030] The parallel platform vibration suppression device 10 includes three inertial mass actuators, which are arranged in three orthogonal directions respectively, 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. Vibration suppression at the natural frequency of multiple degrees of freedom of the parallel platform can be achieved by orthogonally combining the three inertial mass actuators.

[0031] See also 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 may be a spring sheet. The inertial mass block 21 is located in 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.

[0032] 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 via the mounting plate 25. Figure 1 In the illustrated 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. The stator of the voice coil motor 22 can be connected to a side surface of the mounting plate 25 through a mounting bracket 20. The acceleration sensor 24 is provided on the mounting plate 25 for obtaining an acceleration signal. The acceleration sensor 24 can be provided on a side surface of the mounting plate 25.

[0033] See also 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 a parallel platform vibration suppression device 10, and the vibration suppression method includes steps S101-S104.

[0034] 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 working 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 in order to facilitate the subsequent design of the virtual vibration absorber.

[0035] In step S102, a virtual vibration absorber is designed according to the natural frequency.

[0036] In one embodiment, step S102 includes determining stiffness and mass parameters of the virtual vibration absorber by the following formula:

[0037] in, is the stiffness of the virtual vibration absorber, is the mass of the virtual vibration absorber, is the natural frequency.

[0038] In one embodiment, step S102 further includes determining the damping of the virtual vibration absorber by the following formula:

[0039] in, is the damping of the virtual vibration absorber. , the stiffness, mass and damping of the virtual vibration absorber are determined respectively by the above formulas.

[0040] 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.

[0041] In one embodiment, step S103 includes determining the control force generated by the virtual vibration absorber by the following formula:

[0042] in, The control force generated by the virtual vibration absorber, To control the gain, is the complex frequency variable in the Laplace transform, It is the acceleration collected by the acceleration sensor. Control gain The strength 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 and the virtual vibration absorber can be combined 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.

[0043] In step S104, the force output by the inertial mass actuator 16 is determined according to the control force generated by the virtual vibration absorber. 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 arranged in three orthogonal directions respectively, and can output forces in three orthogonal directions, so as to better suppress the vibration of the parallel platform 10.

[0044] The invention adopts a virtual vibration absorber, which can adjust the control parameters of the whole system through software compared with the traditional physical vibration absorber or vibration isolator. When the mass change of the load 15 causes the natural frequency to change, there is no need to change the structure of the whole 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, thereby ensuring the stability of the whole system and effectively suppressing the vibration of the parallel platform 11 at the natural frequency, reducing the high complexity and cost caused by the need to change the mechanical structure of the passive vibration absorber when the natural frequency changes.

[0045] 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 structures, 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, which will not change the dynamic characteristics of the overall system. In addition, the virtual vibration absorber can be more conveniently integrated into the overall system by simulating the effect of the vibration absorber through the inertial mass actuator 16 with software-level control, and can be adapted to a variety of occasions, especially to occasions where it is not desired to make too many changes to the existing design.

[0046] Among them, the controller can adopt 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 collection, 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 load changes and the changes in the natural frequency of the overall system through the dynamic adjustment of the virtual vibration absorber, thereby ensuring the accuracy and stability of the overall system.

[0047] In one embodiment, the parallel platform vibration suppression device 10 includes a bandpass 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 bandpass filter and the notch filter, and inputting it into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber. Setting the bandpass filter and the notch filter can avoid the interference of high-frequency noise of the system and the interference of integral saturation. It can filter out the noise of the acceleration collected by the acceleration sensor 24.

[0048] In one embodiment, the acceleration collected by the acceleration sensor 24 of the inertial mass actuator 16 is obtained, filtered through a bandpass filter and a notch filter, and then input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber. The vibration suppression method also includes: adjusting the working bandwidth of the bandpass 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 bandpass filter and the working bandwidth of the notch filter.

[0049] In one embodiment, adjusting the operating bandwidth of the bandpass filter according to the natural frequency includes: adjusting the center frequency of the bandpass filter and its corresponding first quality factor according to the natural frequency, and adjusting the operating bandwidth of the bandpass filter through the transfer function of the bandpass filter.

[0050] Transfer Function of a Bandpass Filter The formula is as follows:

[0051] in, is the center frequency of the bandpass filter, is the first quality factor. The center frequency of the bandpass filter is usually selected from the natural frequency of the overall system or the middle frequency of the main frequency band of interest. The first quality factor can determine the bandpass width. In this way, the low-frequency signal can be removed by the bandpass filter to reduce the system instability caused by the accumulation of integral errors. In addition, the high-frequency signal can be filtered out to reduce the influence of the high-frequency mode of the parallel platform on the control system of the parallel platform vibration suppression device 10.

[0052] In one embodiment, adjusting the operating bandwidth of the notch filter according to the natural frequency includes: adjusting the center frequency of the notch filter and its corresponding second quality factor according to the natural frequency, and adjusting the operating bandwidth of the notch filter through the transfer function of the notch filter.

[0053] Transfer Function of Notch Filter The formula is as follows:

[0054] in, is the center frequency of the notch filter, is the second quality factor. The center frequency of the notch filter is usually selected from the natural frequency of the overall system or the frequency at which the vibration peak is located. The second quality factor can determine the notch width. In this way, by adjusting the center frequency and bandwidth of the notch filter, the resonant response of the parallel platform 11 at the natural frequency can be accurately suppressed, thereby reducing the impact of the vibration caused by resonance on the overall system.

[0055] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0056] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for suppressing vibration of a parallel platform, characterized in that: Applicable to a parallel platform vibration suppression device, the parallel platform vibration suppression device is arranged on an upper platform of the parallel platform, the upper platform is used to place a load; the parallel platform vibration suppression device includes a controller and three inertial mass actuators, the three inertial mass actuators are arranged in three orthogonal directions respectively, and are used to output forces in three orthogonal directions, and the inertial mass actuator includes an acceleration sensor; The controller is used to execute the vibration suppression method; the vibration suppression method includes: Determining the natural frequency corresponding to the upper platform and the load placed thereon; According to the natural frequency, a virtual vibration absorber is designed; Acquire the acceleration collected by the acceleration sensor of the inertial mass actuator, and input it into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber; The force output by the inertial mass actuator is determined according to the control force generated by the virtual vibration absorber.

2. The parallel platform vibration suppression method according to claim 1, characterized in that: The step of designing a virtual vibration absorber according to the natural frequency comprises: The stiffness and mass parameters of the virtual vibration absorber are determined by the following formula: in, is the stiffness of the virtual vibration absorber, is the mass parameter of the virtual vibration absorber, is the natural frequency.

3. The parallel platform vibration suppression method according to claim 2, characterized in that: The designing of a virtual vibration absorber according to the natural frequency further includes: The damping of the virtual vibration absorber is determined by the following formula: in, is the damping of the virtual vibration absorber.

4. The parallel platform vibration suppression method according to claim 1, characterized in that: The acquiring the acceleration collected by the acceleration sensor of the inertial mass actuator and inputting it into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber includes: The control force generated by the virtual vibration absorber is determined by the following formula: in, is the control force generated by the virtual vibration absorber, To control the 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, It is the acceleration collected by the acceleration sensor.

5. The parallel platform vibration suppression method according to claim 1, characterized in that: The parallel platform vibration suppression device includes a bandpass filter and a notch filter; the acceleration acquired 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: The acceleration collected by the acceleration sensor of the inertial mass actuator is obtained, filtered through the bandpass filter and the notch filter, and then input into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber.

6. The parallel platform vibration suppression method according to claim 5, characterized in that: Before obtaining the acceleration collected by the acceleration sensor of the inertial mass actuator, filtering it through the bandpass filter and the notch filter, and inputting it into the virtual vibration absorber to determine the control force generated by the virtual vibration absorber, the vibration suppression method further includes: According to the natural frequency, the working bandwidth of the bandpass filter and the working bandwidth of the notch filter are adjusted so that the natural frequency is within the working bandwidth of the bandpass filter and the working bandwidth of the notch filter.

7. The parallel platform vibration suppression method according to claim 6, characterized in that: The step of adjusting the working bandwidth of the bandpass filter according to the natural frequency includes: According to the natural frequency, adjusting the center frequency of the bandpass filter and the first quality factor corresponding thereto, and adjusting the working bandwidth of the bandpass filter through the transfer function of the bandpass filter; The transfer function of the bandpass filter is The formula is as follows: in, is the center frequency of the bandpass filter, is the first quality factor, is the complex frequency variable in the Laplace transform.

8. The parallel platform vibration suppression method according to claim 6, characterized in that: The step of 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; The transfer function of the notch filter is The formula is as follows: in, is the center frequency of the notch filter, is the second quality factor, is the complex frequency variable in the Laplace transform.

9. A parallel platform vibration suppression device, characterized in that: Used to execute the parallel platform vibration suppression method as described in any one of claims 1-8.

10. The parallel platform vibration suppression device according to claim 9, characterized in that: The inertial mass actuator comprises a mounting bracket, an inertial mass block, a voice coil motor and an elastic member; the inertial mass block is located in 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, the mover of the voice coil motor is connected to the inertial mass block, and 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 comprises an acceleration sensor and a mounting plate, and 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 obtain an acceleration signal.

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