Control Method and Device of Active Vibration Isolation Device

Abstract

The present invention relates to the field of active vibration isolation, and particularly to a control method and device for an active vibration isolation device. The active vibration isolation device includes a controller, a load, a passive vibration isolation unit for supporting the load, a base arranged on the ground, and a plurality of inertial mass actuators arranged on the load. The centroid of the base is set corresponding to the centroid of the load. Each inertial mass actuator is correspondingly provided with a feedback sensor, so that a plurality of feedback sensors are arranged on the load. A plurality of feedforward sensors are arranged on the base. The control method for active vibration isolation includes obtaining the feedback acceleration collected by the feedback sensors, and determining the feedback control force corresponding to each inertial mass actuator according to the feedback acceleration. Obtaining the feedforward acceleration collected by the feedforward sensors, and determining the feedforward control force corresponding to each inertial mass actuator according to the feedforward acceleration. Determining the output force of each inertial mass actuator according to the feedback control force and the feedforward control force. The effective suppression of the vibration of the load is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of active vibration isolation, and particularly relates to a control method and device for an active vibration isolation device. Background Art

[0002] Active vibration isolation systems are widely used in high-precision optical systems, precision manufacturing, spacecraft platforms, flexible structures and other fields to suppress the influence of external vibrations on the performance of equipment. The active vibration isolation scheme based on voice coil motors monitors vibrations in real time through accelerometers or displacement sensors, and the controller precisely adjusts the output of the voice coil motor to generate a reverse force to eliminate vibrations. Voice coil motors have the advantages of fast response speed, high linearity, high precision and no mechanical transmission. They can respond in the microsecond level and adapt to complex vibration environments, especially suitable for high-frequency vibration suppression. This scheme can not only effectively isolate low-frequency vibrations, but also precisely adjust high-frequency vibrations. It is widely used in the load precision control of space optical equipment and the suppression of micro-vibrations of precision machining equipment, significantly improving the stability, precision and operating efficiency of the equipment. However, since the change of the center of mass of the load has a significant impact on the active vibration isolation system, the center of mass offset may cause the generation of asymmetric torques, thereby affecting the vibration response of the load and reducing the vibration isolation effect. In addition, the change of the center of mass will change the force distribution of the actuator, increasing the complexity and computational requirements of the active vibration isolation system, resulting in uneven vibration suppression effects.

[0003] The existing active vibration isolation systems integrate passive vibration isolation elements and active actuators such as voice coil motors into an isolation unit. Although it provides high flexibility and high control precision, there are still some significant disadvantages and deficiencies. First, the modular design increases the complexity of the active vibration isolation system. Precise integration of passive vibration isolation elements and active vibration isolation elements not only increases the design and development difficulty, but also increases the system cost and maintenance complexity. When designing, it is necessary to consider not only the distribution of passive vibration isolation devices, but also the installation layout of active vibration isolation elements such as voice coil motors, which limits the design of the active vibration isolation system. In addition, due to the need for support, the modular isolation unit needs to be installed under the load. When the center of mass of the load is too high, the active control force output by the voice coil motor becomes more complex with respect to the control torque of the center of mass of the load, resulting in poor adaptability and flexibility between isolation units, which may lead to poor coordination between different isolation units, thereby affecting the stability and vibration isolation effect of the overall active vibration isolation system. Generally speaking, although this modular active vibration isolation system provides flexible control means, its disadvantages such as design complexity, energy efficiency issues, cost and maintenance challenges also limit its promotion in some applications.

[0004] An invention patent application with Chinese Patent Publication No. CN118224239A, publication date of June 21, 2024, and patent name of "A Triangular Six-Degree-of-Freedom Active Vibration Isolation Platform". It discloses a triangular six-degree-of-freedom active vibration isolation platform, including a support base, a bearing plate, a connecting plate, and a lateral support seat. The lateral support seats are arranged between the support base and the bearing plate, and three lateral support seats enclose to form a triangular structure. The bottom of the lateral support seat is connected to the support base through a vertically arranged voice coil motor and a high-static low-dynamic damping component connected in parallel. A connecting plate is vertically arranged between adjacent lateral support seats, and the lateral supports are connected to the connecting plates one by one. The lateral support seat is connected to the connecting plate through a horizontally arranged voice coil motor and a spring connected in parallel. Acceleration sensors are installed at the positions of the lateral support seat corresponding to the horizontal voice coil motor and the vertical voice coil motor. In the invention, the number of acceleration sensors and spring actuation components is reduced, thereby reducing the time delay problem between sensors, reducing the out-of-synchronization problem between voice coil motors, and improving the active control accuracy of vibration. However, this method places higher requirements on passive vibration isolation design, and integrating active vibration isolation units makes the design more complex and the installation more difficult, and it is impossible to transform the existing passive vibration isolation platform. Summary of the Invention

[0005] In view of this, the present invention aims to provide an active vibration isolation device and its control method, which can effectively suppress the vibration of the load through multiple inertial mass actuators.

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

[0007] A control method for an active vibration isolation device, applied to the active vibration isolation device; the active vibration isolation device includes a controller, a load, a passive vibration isolation unit for supporting the load, a base arranged on the ground, and multiple inertial mass actuators arranged on the load; the center of mass of the base is set corresponding to the center of mass of the load; each inertial mass actuator is correspondingly provided with a feedback sensor, so that multiple feedback sensors are arranged on the load; multiple feedforward sensors are arranged on the base; the controller is used to execute the control method, and the control method includes:

[0008] Obtain the feedback acceleration collected by the feedback sensor, and determine the feedback control force corresponding to each inertial mass actuator according to the feedback acceleration;

[0009] Obtain the feedforward acceleration collected by the feedforward sensor, and determine the feedforward control force corresponding to each inertial mass actuator according to the feedforward acceleration;

[0010] Determine the output force of each inertial mass actuator according to the feedback control force and the feedforward control force.

[0011] Further, obtain the feedback acceleration collected by the feedback sensor, and determine the feedback control force corresponding to each inertial mass actuator according to the feedback acceleration, including:

[0012] Determine the feedback control force corresponding to each inertial mass actuator through the following formula:

[0013]

[0014] Wherein, is the feedback control force corresponding to the i-th inertial mass actuator, is the transfer function of the feedback controller, is the feedback acceleration collected by the feedback sensor corresponding to the i-th inertial mass actuator.

[0015] Further, obtain the feedback acceleration collected by the feedback sensor, and determine the feedback control force corresponding to each inertial mass actuator, further including:

[0016] Determine the transfer function of the feedback controller through the following formula :

[0017]

[0018] Wherein, is the transfer function of the PI controller, is the transfer function of the first-order high-pass filter, is the transfer function of the second-order low-pass filter, is the transfer function of the lead-lag phase compensation filter, is the transfer function of the notch filter.

[0019] Further, determine the transfer function of the PI controller through the following formula :

[0020]

[0021] Wherein, is the acceleration feedback gain, is the absolute velocity feedback gain, is the complex frequency variable in the Laplace transform;

[0022] Determine the transfer function of the first-order high-pass filter through the following formula :

[0023]

[0024] Wherein, is the high-pass cut-off frequency of the feedback controller;

[0025] The transfer function of the second-order low-pass filter is determined by the following formula :

[0026]

[0027] where is the low-pass cut-off frequency of the feedback controller;

[0028] The transfer function of the lead-lag phase compensation filter is determined by the following formula :

[0029]

[0030] where K is the gain of the lead-lag phase compensation filter, is the frequency of the pole, is the frequency of the zero;

[0031] The transfer function of the notch filter is determined by the following formula :

[0032]

[0033] where is the notch filter gain, is the notch frequency of the notch filter, is the bandwidth of the notch filter, is the depth of the notch filter; .

[0034] Furthermore, the number of feedforward sensors is six. Every two feedforward sensors among the six feedforward sensors form a group, so as to form three groups of feedforward sensor groups. The three groups of feedforward sensor groups are distributed on the circumference of a circle formed with the centroid of the base as the center and a set radius as the radius; wherein, one feedforward sensor in a group of feedforward sensor groups collects the acceleration in the vertical direction, and the other feedforward sensor collects the acceleration in the direction tangent to the circle; obtaining the feedforward acceleration collected by the feedforward sensors, and determining the feedforward control force corresponding to each inertial mass actuator according to the feedforward acceleration, including:

[0035] Obtaining the feedforward acceleration collected by the feedforward sensors, and integrating the feedforward accelerations collected by multiple feedforward sensors at the centroid of the base, so as to obtain the comprehensive acceleration in six directions at the centroid of the base;

[0036] Determining the comprehensive control force in six directions at the centroid of the load according to the comprehensive acceleration in six directions at the centroid of the base;

[0037] Determining the feedforward control force corresponding to each inertial mass actuator according to the comprehensive control force in six directions at the centroid of the load.

[0038] Further, obtain the feedforward acceleration collected by the feedforward sensors, and integrate the feedforward accelerations collected by multiple feedforward sensors at the centroid of the base to obtain the combined accelerations in six directions at the centroid of the base, including:

[0039] Determine the combined accelerations in six directions at the centroid of the base through the following formula:

[0040]

[0041] where, is an array formed by the feedforward accelerations collected by six feedforward sensors, is an array formed by the combined accelerations in six directions at the centroid of the base, is the transformation matrix from the feedforward acceleration collected by each feedforward sensor to the combined accelerations in six directions at the centroid of the base, is the radius setting value.

[0042] Further, determine the combined control forces in six directions at the centroid of the load according to the combined accelerations in six directions at the centroid of the base, including:

[0043] Determine the combined control forces in six directions at the centroid of the load through the following formula:

[0044]

[0045] where, is the transfer function of the feedforward sensor, is an array formed by the combined accelerations in six directions at the centroid of the base, is an array formed by the combined control forces in six directions at the centroid of the load, are the forces in three directions at the centroid of the load, are the torques in three directions at the centroid of the load;

[0046] The transfer function of the feedforward controller is:

[0047]

[0048] where, is the feedforward gain of the damping term, is the feedforward gain of the stiffness term;

[0049]

[0050]

[0051] where, p is the cut-off frequency of the weak integrator, is the complex frequency variable in the Laplace transform.

[0052] Furthermore, according to the comprehensive control forces in six directions at the centroid of the load, determine the feedforward control forces corresponding to each inertial mass actuator, including:

[0053] Determine the feedforward control forces corresponding to each inertial mass actuator through the following formula:

[0054]

[0055]

[0056] where is an array formed by the feedforward control forces corresponding to multiple inertial mass actuators, is the transformation matrix from the feedforward control force corresponding to the inertial mass actuator to the comprehensive control forces in six directions at the centroid of the load, are the forces in three directions at the centroid of the load, are the torques in three directions at the centroid of the load, is the distance from the inertial mass actuator to the centroid of the load in the vertical direction, is the distance from the inertial mass actuator to the centroid of the load in the horizontal direction.

[0057] Furthermore, according to the feedback control force and the feedforward control force, determine the output force of each inertial mass actuator, including:

[0058] Determine the output force of each inertial mass actuator through the following formula:

[0059]

[0060] where is an array formed by the output forces of multiple inertial mass actuators, is an array formed by the feedforward control forces corresponding to multiple inertial mass actuators, is an array formed by the feedback control forces corresponding to multiple inertial mass actuators.

[0061] An active vibration isolation device is used to execute the control method of the active vibration isolation device as described above.

[0062] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0063] Based on a passive vibration isolation system composed of passive vibration isolation units, the present invention can add an active vibration isolation function by adding an inertial mass actuator, transforming the passive vibration isolation system into an active vibration isolation device with an active vibration isolation function. Thus, there is no need to set active actuators such as voice coil motors in the passive vibration isolation units, which can simplify the design of the passive vibration isolation units, make the passive vibration isolation units more compact, and improve the stiffness of the passive vibration isolation units. It can be applied to active vibration isolation devices with high natural frequencies, has strong anti-interference characteristics, and ensures the ability to suppress internal disturbances of the load under hard installation. Moreover, the use of an inertial mass actuator is conducive to installation and configuration change, with stronger adaptability. At the same time, after the center of mass of the load changes, the installation position of the inertial mass actuator can be adjusted accordingly to achieve six-degree-of-freedom vibration control of the load, effectively suppressing the vibration of the load, reducing the complexity of the mechanical structure, and reducing costs. Description of the Drawings

[0064] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0065] Figure 1 Schematic diagram of the active vibration isolation device according to an embodiment of the present invention;

[0066] Figure 2 Schematic diagram of the inertial mass actuator according to an embodiment of the present invention;

[0067] Figure 3 Force distribution diagram of the inertial mass actuator on the load according to an embodiment of the present invention;

[0068] Figure 4 Schematic diagram of the distribution of the feedforward sensors on the base according to an embodiment of the present invention;

[0069] Figure 5 Flowchart of the control method of the active vibration isolation device according to an embodiment of the present invention;

[0070] Figure 6 Further flowchart of the control method of the active vibration isolation device according to an embodiment of the present invention.

[0071] Description of the Reference Numerals:

[0072] Active vibration isolation device 10; Load 11; Passive vibration isolation unit 12; Base 13; Inertial mass actuator 14; Mounting bracket 15; Inertial mass block 16; Voice coil motor 17; Elastic member 18; Feedback sensor 19; Feedforward sensor 20; Feedforward sensor group 21. Detailed Description of the Invention

[0073] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further details the present invention in combination with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many detailed descriptions are provided 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 descriptions. 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 descriptions in the specification and the general technical knowledge in the art.

[0074] 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.

[0075] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "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 accompanying drawings, and 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 cannot be understood as a limitation to the present invention. In addition, terms such as "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, 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.

[0076] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" 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 an indirect connection through an intermediate medium, and it can be the communication inside two components. 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.

[0077] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0078] See Figure 1 As shown, an active vibration isolation device 10 is provided in an embodiment of the present invention. The active vibration isolation device 10 includes a controller, and the controller is used to execute the control method of the active vibration isolation device. The controller can adopt a PLC. The controller can include a feedback controller and a feedforward controller, and the feedback controller and the feedforward controller are virtual controllers. The feedback controller can include a PI controller, a first-order high-pass filter, a second-order low-pass filter, a lead-lag phase compensation filter, and a notch filter. The feedforward controller can include a high-pass filter, a lead-lag phase compensation filter, and a notch filter.

[0079] In one embodiment, the active vibration isolation device 10 includes a load 11, a passive vibration isolation unit 12 for supporting the load 11, a base 13 arranged on the ground, and a plurality of inertial mass actuators 14 arranged on the load 11. The passive vibration isolation unit 12 can be a spring-damper unit, which can play a supporting role and isolate the vibration of the ground. In Figure 1 In the shown embodiment, the number of the passive vibration isolation units 12 is four. The centroid of the base 13 is set corresponding to the centroid of the load 11, that is, the centroid of the base 13 and the centroid of the load 11 are on the same straight line perpendicular to the ground.

[0080] See Figure 1 and Figure 2 As shown, in one embodiment, the inertial mass actuator 14 includes a mounting bracket 15, an inertial mass block 16, a voice coil motor 17, and an elastic member 18. The elastic member 18 can be a spring sheet. The inertial mass block 16 is located inside the mounting bracket 15, and the side wall of the inertial mass block 16 is connected to the inner wall of the mounting bracket 15 through the elastic member 18. The stator of the voice coil motor 17 is connected to the mounting bracket 15, the mover of the voice coil motor 17 is connected to the inertial mass block 16, and the voice coil motor 17 is used to drive the inertial mass block 16 to move so as to act on the load 11 through the elastic member 18 and the mounting bracket 15.

[0081] In one embodiment, each inertial mass actuator 14 is correspondingly provided with a feedback sensor 19, so that a plurality of feedback sensors 19 are provided on the load 11. The feedback sensor 19 can collect the feedback acceleration, where the feedback acceleration refers to the acceleration collected by the feedback sensor 19. The feedback sensor 19 is combined with each inertial mass actuator 14 to achieve one-to-one skyhook damping control.

[0082] See Figure 3 As shown, in one embodiment, the output force directions of at least one inertial mass actuator 14 among the plurality of inertial mass actuators 14 are in the first direction X, the output force directions of at least one inertial mass actuator 14 are in the second direction Y, and the output force directions of at least one inertial mass actuator 14 are in the third direction Z. Among them, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. In Figure 3 the embodiment shown, the number of inertial mass actuators 14 is eight, and the output force directions of two inertial mass actuators 14 are in the first direction X, which are respectively , . The output force directions of two inertial mass actuators 14 are in the second direction Y, which are respectively , . The output force directions of four inertial mass actuators 14 are in the third direction Z, which are respectively , , .

[0083] In this embodiment, when designing the distribution of the inertial mass actuators 14, two aspects of factors need to be considered. First, it is physically realizable, so that the eight inertial mass actuators 14 can cooperate with each other to achieve six-degree-of-freedom vibration control of the load 11. The six degrees of freedom of the load 11 are Figure 3 the X-axis direction, the Y-axis direction, the Z-axis direction, the direction around the X-axis, the direction around the Y-axis, and the direction around the Z-axis shown in

[0084] See Figure 4 As shown, a plurality of feedforward sensors 20 are provided on the base 13. The plurality of feedforward sensors 20 are installed on the ground through the base 13, and decoupling control can be performed on each inertial mass actuator 14 by using the feedforward sensors 20. The number of feedforward sensors 20 is six, and every two of the six feedforward sensors 20 form a group to form three groups of feedforward sensor groups 21. The three groups of feedforward sensor groups 21 are distributed with the centroid of the base 13 as the center of the circle and a radius set value On the circumference of a circle formed with a radius. Among them, one feedforward sensor 20 in each group of feedforward sensor groups 21 collects the acceleration in the vertical direction, and the other feedforward sensor 20 collects the acceleration in the direction tangent to the circle. In Figure 4 In the illustrated embodiment, the feedforward sensor and the feedforward sensor form a group, the feedforward sensor and the feedforward sensor form a group, the feedforward sensor and the feedforward sensor form a group. Among them, the feedforward sensors , , respectively collect the acceleration in the vertical direction of the ground in a direction perpendicular to both the radial and tangential directions of the circle, and the feedforward sensors , , respectively collect the acceleration in the direction tangent to the circle.

[0085] See Figure 3 , Figure 4 and Figure 5 shown, the embodiment of the present invention provides a control method for an active vibration isolation device, which is applied to the active vibration isolation device 10, and the control method includes steps S101 to S103.

[0086] In step S101, obtain the feedback acceleration collected by the feedback sensor 19, and determine the feedback control force corresponding to each inertial mass actuator 14 according to the feedback acceleration. Among them, the feedback acceleration is the acceleration on the load 11. A feedback controller can be designed correspondingly. In this way, the vibration of the active vibration isolation device 10 at the natural frequency can be suppressed, so that the active vibration isolation device 10 remains stable.

[0087] In one embodiment, step S101 includes: determining the feedback control force corresponding to each inertial mass actuator 14 through the following formula:

[0088]

[0089] Among them, is the feedback control force corresponding to the i-th inertial mass actuator 14, is the transfer function of the feedback controller, is the feedback acceleration collected by the feedback sensor 19 corresponding to the i-th inertial mass actuator 14. In this embodiment, the number of inertial mass actuators 14 is eight, and the feedback control forces corresponding to the eight inertial mass actuators 14 can be respectively expressed as , , , , , , , .

[0090] In one embodiment, step S101 further includes: determining the transfer function of the feedback controller through the following formula :

[0091]

[0092] wherein, is the transfer function of the PI controller, is the transfer function of the first-order high-pass filter, is the transfer function of the second-order low-pass filter, is the transfer function of the lead-lag phase compensation filter, is the transfer function of the notch filter. Adding a band-pass filter (i.e., a first-order high-pass filter and a second-order low-pass filter) and a notch filter can avoid the interference of high-frequency noise and integral saturation of the active vibration isolation device 10. The resonance response of the active vibration isolation device 10 at the natural frequency can be precisely suppressed by adjusting the frequencies and bandwidths of the band-pass filter and the notch filter, thereby reducing the influence of the vibration caused by resonance on the active vibration isolation device 10.

[0093] The basis of the feedback controller is the PI controller. In one embodiment, the transfer function of the PI controller is determined through the following formula :

[0094]

[0095] wherein, is the acceleration feedback gain, is the absolute velocity feedback gain, is the complex frequency variable in the Laplace transform. The acceleration feedback gain can provide virtual mass for the load 11, change the resonant frequency of the active vibration isolation device 10, and enhance the ability to suppress high-frequency interference. The absolute velocity feedback gain can provide skyhook damping for the active vibration isolation device 10 and enhance the suppression ability of the active vibration isolation device at the resonant frequency.

[0096] In the process of processing the feedback acceleration by the feedback controller, it is necessary to prevent integral drift and saturation of the inertial mass actuator 14. Among them, integral drift refers to the saturation effect that will occur under low-frequency signals. Therefore, it is necessary to add a first-order high-pass filter for filtering. The transfer function of the first-order high-pass filter is determined through the following formula :

[0097]

[0098] Among them, is the high-pass cut-off frequency of the feedback controller.

[0099] Generally, the smaller the high-pass cut-off frequency of the first-order high-pass filter, the smaller the phase lead in the passband, and the better the integrator performance. However, at the same time, the smaller the frequency, it will cause integral saturation of the feedback controller and poor stability of the high-pass filter. Using the feedback controller cannot suppress the high-frequency resonance peak of the active vibration isolation device, and may even amplify the disturbance of the base 11. Therefore, to achieve frequency band division control, so that the active control of the feedback controller only acts on the low-frequency band, will not affect the high-frequency mode, and can suppress the influence of high-frequency noise during the acceleration acquisition by the feedback sensor 19 on the active vibration isolation device, a second-order low-pass filter is added. The transfer function of the second-order low-pass filter is determined by the following formula :

[0100]

[0101] Among them, is the low-pass cut-off frequency of the feedback controller.

[0102] Introducing the first-order high-pass filter and the second-order low-pass filter will affect the phase of the feedback controller, resulting in a decrease in the stability of the feedback controller. The feedback control gain of the PI controller is too high, resulting in insufficient phase margin of the open loop and prone to oscillation. To ensure the stability and phase margin of the feedback controller, a lead-lag phase compensation filter needs to be added in the control of the feedback controller. The transfer function of the lead-lag phase compensation filter is determined by the following formula :

[0103]

[0104] Among them, K is the gain of the lead-lag phase compensation filter, is the frequency of the pole, is the frequency of the zero.

[0105] To suppress the influence of the noise generated by individual high-frequency modes of the active vibration isolation device 10 on the feedback controller, a notch filter is added. The transfer function of the notch filter is determined by the following formula :

[0106]

[0107] Among them, is the notch filter gain, is the notch frequency of the notch filter, is the bandwidth of the notch filter, is the depth of the notch filter. .

[0108] In step S102, the feedforward acceleration collected by the feedforward sensor 20 is obtained, and according to the feedforward acceleration, the feedforward control force corresponding to each inertial mass actuator 14 is determined. Among them, the feedforward acceleration is the acceleration of the base 13, that is, the acceleration of the ground. A feedforward controller can be designed correspondingly. Using the feedforward controller to control can effectively expand the vibration isolation bandwidth of the active vibration isolation device 10.

[0109] See Figure 3 、 Figure 4 and Figure 6 As shown in

[0110] In step S201, the feedforward acceleration collected by the feedforward sensor 20 is obtained, and the feedforward accelerations collected by the multiple feedforward sensors 20 are integrated at the centroid of the base 13 to obtain the six-direction comprehensive acceleration at the centroid of the base 13.

[0111] In one embodiment, step S201 includes: determining the six-direction comprehensive acceleration at the centroid of the base 13 through the following formula:

[0112] The acceleration of the base 13 can be expressed as:

[0113]

[0114] Among them, is an array formed by the feedforward accelerations collected by the six feedforward sensors 20, , is an array formed by the six-direction comprehensive accelerations at the centroid of the base 13, , is the transformation matrix from the feedforward acceleration collected by each feedforward sensor 20 to the six-direction comprehensive acceleration at the centroid of the base 13, is the radius setting value. Among them, in the array formed by the six-direction comprehensive accelerations at the centroid of the load 11 represents the acceleration of the base 13 in the X direction, represents the acceleration of the base 13 in the Y direction, represents the acceleration of the base 13 in the Z direction, represents the direction acceleration of the base 13, represents the direction acceleration of the base 13, represents the direction acceleration of the base 13. Among them, the direction is the direction around the X axis, The direction is the direction around the Y-axis, The direction is the direction around the Z-axis.

[0115] In step S202, according to the combined accelerations in six directions at the centroid of the base 13, determine the combined control forces in six directions at the centroid of the load 11.

[0116] In one embodiment, step S202 includes: determining the combined control forces in six directions at the centroid of the load 11 through the following formula:

[0117]

[0118] Wherein, is the transfer function of the feedforward sensor 20, is an array formed by the combined accelerations in six directions at the centroid of the base 13, is an array formed by the combined control forces in six directions at the centroid of the load 11, is the force in three directions at the centroid of the load 11, is the moment in three directions at the centroid of the load 11. ; . Wherein, is the force in the X direction, is the force in the Y direction, is the force in the Z direction. is the moment around the X direction, is the moment around the Y direction, is the moment around the Z direction.

[0119] The transfer function of the feedforward controller is:

[0120]

[0121] Wherein, is the feedforward gain of the damping term, is the feedforward gain of the stiffness term. The feedforward gain of the damping term can achieve the cancellation of the vibration transmission of the damping term of the active vibration isolation device 10, and the feedforward gain of the stiffness term can achieve the cancellation of the vibration transmission of the stiffness term of the active vibration isolation device 10.

[0122]

[0123]

[0124] Wherein, p is the cut-off frequency of the weak integrator, is the complex frequency variable in the Laplace transform. Since the weak integrator has a built-in low-pass filtering effect, there is no need to additionally add a low-pass filter. In addition, like the feedback controller, in order to avoid the influence of the phase delay of the feed-forward controller and the high-frequency mode of the feed-forward controller, a lead-lag phase compensation filter and a notch filter .

[0125] In step S203, according to the comprehensive control forces in six directions at the centroid of the load 11, the feed-forward control force corresponding to each inertial mass actuator 14 is determined.

[0126] In one embodiment, step S203 includes: determining the feed-forward control force corresponding to each inertial mass actuator 14 through the following formula:

[0127]

[0128]

[0129] wherein, is an array formed by the feed-forward control forces corresponding to multiple inertial mass actuators 14. In this embodiment, the number of inertial mass actuators 14 is eight, , that is, the feed-forward control forces corresponding to the eight inertial mass actuators 14 can be respectively expressed as , , , , , , , . is the transformation matrix from the feed-forward control force corresponding to the inertial mass actuator 14 to the comprehensive control forces in six directions at the centroid of the load 11, are the forces in three directions at the centroid of the load 11, are the torques in three directions at the centroid of the load 11, is the distance from the inertial mass actuator 14 to the centroid of the load 11 in the vertical direction, is the distance from the inertial mass actuator 14 to the centroid of the load 11 in the horizontal direction.

[0130] In step S103, according to the feedback control force and the feed-forward control force, the output force of each inertial mass actuator 14 is determined.

[0131] In one embodiment, step S103 includes: determining the output force of each inertial mass actuator 14 through the following formula:

[0132]

[0133] Among them, is an array formed by the output forces of multiple inertial mass actuators 14, is an array formed by the feedforward control forces corresponding to the multiple inertial mass actuators 14, is an array formed by the feedback control forces corresponding to the multiple inertial mass actuators 14.

[0134]

[0135]

[0136]

[0137] Based on the passive vibration isolation system composed of passive vibration isolation units, the present invention can add an active vibration isolation function by adding inertial mass actuators 14, and transform the passive vibration isolation system into an active vibration isolation device 10 with an active vibration isolation function. Thus, there is no need to set active actuators such as voice coil motors in the passive vibration isolation unit 12, which can simplify the design of the passive vibration isolation unit 12, make the passive vibration isolation unit 12 more compact, and improve the stiffness of the passive vibration isolation unit 12. It can be applied to the active vibration isolation device 10 with a high natural frequency, has strong anti-interference characteristics, and ensures the suppression ability of internal disturbances of the load 11 when the active vibration isolation device 10 has a high stiffness and natural frequency. Moreover, the use of inertial mass actuators 14 is beneficial to installation and configuration change, and has stronger adaptability. At the same time, after the centroid of the load 11 changes, the installation position of the inertial mass actuators 14 can be adjusted correspondingly to achieve six-degree-of-freedom vibration control of the load 11, effectively suppressing the vibration of the load 11, reducing the complexity of the mechanical structure, and reducing the cost.

[0138] It should be understood that the various forms of processes shown above can be used, and steps can be reordered, added, or deleted. For example, the steps recorded in the disclosure of the present invention can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions disclosed in the present invention can be achieved, and no limitations are imposed herein.

[0139] The above specific embodiments do not constitute a limitation to 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 principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A control method for an active vibration isolation device, characterized in that: Applicable to an active vibration isolation device; the active vibration isolation device comprises a controller, a load, a passive vibration isolation unit for supporting the load, a base arranged on the ground and a plurality of inertial mass actuators arranged on the load; the center of mass of the base is arranged corresponding to the center of mass of the load; each of the inertial mass actuators is provided with a feedback sensor, so that a plurality of the feedback sensors are provided on the load; a plurality of feedforward sensors are provided on the base; the number of the feedforward sensors is six, and every two of the six feedforward sensors form a group to form three groups of feedforward sensor groups, and the three groups of feedforward sensor groups are distributed on the circumference of a circle formed with the center of mass of the base as the center and a radius set value as the radius; wherein one of the feedforward sensors in a group of the feedforward sensor groups collects acceleration in the vertical direction, and another feedforward sensor collects acceleration in the direction along the tangent of the circle; the controller is used to execute the control method, and the control method comprises: Acquire the feedback acceleration collected by the feedback sensor, and determine the feedback control force corresponding to each of the inertial mass actuators according to the feedback acceleration; The feedforward acceleration collected by the feedforward sensor is obtained, and the feedforward control force corresponding to each of the inertial mass actuators is determined according to the feedforward acceleration; the feedforward acceleration collected by the feedforward sensor is obtained, and the feedforward accelerations collected by the multiple feedforward sensors are integrated at the center of mass of the base to obtain the comprehensive accelerations in six directions at the center of mass of the base; the comprehensive accelerations in six directions at the center of mass of the base are determined by the following formula: in, is an array formed by the feedforward accelerations collected by the six feedforward sensors, is an array of the integrated accelerations in six directions at the center of mass of the base, is a conversion matrix of the feedforward acceleration collected by each feedforward sensor to the comprehensive acceleration in six directions at the center of mass of the base, setting a value for the radius; represents the acceleration of the base in the X direction, represents the acceleration of the base in the Y direction, represents the acceleration of the base in the Z direction, Representing the base The acceleration in the direction, Representing the base The acceleration in the direction, Representing the base The acceleration in the direction of The direction is around the X axis. The direction is around the Y axis. The direction is around the Z axis; Determine the comprehensive control force in six directions at the center of mass of the load according to the comprehensive acceleration in six directions at the center of mass of the base; Determining a feedforward control force corresponding to each of the inertial mass actuators according to the comprehensive control forces in six directions at the mass center of the load; An output force of each of the inertial mass actuators is determined based on the feedback control force and the feedforward control force.

2. The control method of the active vibration isolation device according to claim 1, characterized in that: The obtaining of the feedback acceleration collected by the feedback sensor and determining the feedback control force corresponding to each of the inertial mass actuators according to the feedback acceleration includes: The feedback control force corresponding to each of the inertial mass actuators is determined by the following formula: in, is the feedback control force corresponding to the i-th inertial mass actuator, is the transfer function of the feedback controller, is the feedback acceleration collected by the feedback sensor corresponding to the i-th inertial mass actuator.

3. The control method of the active vibration isolation device according to claim 2, characterized in that: The obtaining of the feedback acceleration collected by the feedback sensor, and determining the feedback control force corresponding to each of the inertial mass actuators according to the feedback acceleration, further includes: The transfer function of the feedback controller is determined by the following formula: : in, is the transfer function of the PI controller, is the transfer function of the first-order high-pass filter, is the transfer function of the second-order low-pass filter, is the transfer function of the lead-lag phase compensation filter, is the transfer function of the notch filter.

4. The control method of the active vibration isolation device according to claim 3, characterized in that: The transfer function of the PI controller is determined by the following formula: : in, is the acceleration feedback gain, is the absolute speed feedback gain, is the complex frequency variable in Laplace transform; The transfer function of the first-order high-pass filter is determined by the following formula: : in, is the high-pass cutoff frequency of the feedback controller; The transfer function of the second-order low-pass filter is determined by the following formula: : in, is the low-pass cutoff frequency of the feedback controller; The transfer function of the lead-lag phase compensation filter is determined by the following formula: : Where K is the gain of the lead-lag phase compensation filter, is the frequency of the pole, is the frequency of zero point; The transfer function of the notch filter is determined by the following formula: : in, is the notch filter gain, is the notch frequency of the notch filter, is the bandwidth of the notch filter, is the depth of the notch filter; .

5. The control method of the active vibration isolation device according to claim 1, characterized in that: Determining the comprehensive control force in six directions at the center of mass of the load according to the comprehensive acceleration in six directions at the center of mass of the base includes: The combined control forces in the six directions at the center of mass of the load are determined by the following formula: in, is the transfer function of the feedforward sensor, is an array of the integrated accelerations in six directions at the center of mass of the base, is an array of the combined control forces in six directions at the center of mass of the load, are the forces in three directions at the center of mass of the load, are the moments in three directions at the center of mass of the load; Transfer function of feedforward controller for: in, is the damping term feedforward gain, is the stiffness term feedforward gain; in, p is the cutoff frequency of the weak integrator, is the complex frequency variable in the Laplace transform.

6. The control method of the active vibration isolation device according to claim 1, characterized in that: Determining the feedforward control force corresponding to each of the inertial mass actuators according to the comprehensive control forces in six directions at the mass center of the load includes: The feedforward control force corresponding to each of the inertial mass actuators is determined by the following formula: in, is an array formed by the feedforward control forces corresponding to the plurality of inertial mass actuators, is the conversion matrix of the feedforward control force corresponding to the inertial mass actuator to the comprehensive control force in six directions at the center of mass of the load, are the forces in three directions at the center of mass of the load, are the moments in three directions at the center of mass of the load, is the distance from the inertial mass actuator to the mass center of the load in the vertical direction, is the distance from the inertial mass actuator to the mass center of the load in the horizontal direction; The number of inertial mass actuators is eight, and the feedforward control forces corresponding to the eight inertial mass actuators can be expressed as , , , , , , , ; is the force in the X direction, is the force in the Y direction, is the force in the Z direction; is the moment about the X direction, is the moment about the Y direction, is the moment about the Z direction.

7. The control method of the active vibration isolation device according to claim 1, characterized in that: The step of determining the output force of each of the inertial mass actuators according to the feedback control force and the feedforward control force comprises: The output force of each of the inertial mass actuators is determined by the following formula: in, is an array formed by the output forces of a plurality of the inertial mass actuators, is an array formed by the feedforward control forces corresponding to the plurality of inertial mass actuators, An array is formed by the feedback control forces corresponding to the plurality of inertial mass actuators.

8. An active vibration isolation device, characterized in that: A control method for executing the active vibration isolation device according to any one of claims 1 to 7.

Images