Control method of active vibration isolation device and device thereof

Abstract

The invention relates to the field of active vibration isolation, in particular to a control method and device of an active vibration isolation device, and 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 mass center of the base corresponds to the mass center of the load. And each inertial mass actuator is correspondingly provided with a feedback sensor, so that a plurality of feedback sensors are arranged on the load. And a plurality of feed-forward sensors are arranged on the base. The active vibration isolation control method comprises the steps that feedback acceleration collected by the feedback sensor is obtained, and feedback control force corresponding to each inertial mass actuator is determined according to the feedback acceleration. The feedforward acceleration collected by the feedforward sensor is obtained, and the feedforward control force corresponding to each inertial mass actuator is determined according to the feedforward acceleration. And determining the output force of each inertial mass actuator according to the feedback control force and the feedforward control force. And effective suppression of load vibration is realized.

Description

Technical Field

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

[0002] Active vibration isolation systems are widely used in high-precision optical systems, precision manufacturing, spacecraft platforms, and flexible structures to suppress the impact of external vibrations on equipment performance. The active vibration isolation solution based on voice coil motors monitors vibrations in real time through accelerometers or displacement sensors, and the controller accurately adjusts the reverse force output by the voice coil motor 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 microseconds and adapt to complex vibration environments. They are especially suitable for high-frequency vibration suppression. This solution can not only effectively isolate low-frequency vibrations, but also accurately adjust high-frequency vibrations. It is widely used in load precision control of space optical equipment and micro-vibration suppression of precision machining equipment, significantly improving the stability, precision, and operating efficiency of the equipment. However, since the change in the center of mass of the load will have a significant impact on the active vibration isolation system, the center of mass offset may lead to the generation of asymmetric torque, thereby affecting the vibration response of the load and reducing the vibration isolation effect. In addition, the change in the center of mass will change the force distribution of the actuator, increase the complexity and calculation requirements of the active vibration isolation system, and lead to uneven vibration suppression effect.

[0003] The existing active vibration isolation system integrates passive vibration isolation elements and active actuators such as voice coil motors into one vibration isolation unit. Although it provides high flexibility and high control accuracy, it still has some significant disadvantages and shortcomings. First, the modular design increases the complexity of the active vibration isolation system. It requires precise integration of passive vibration isolation elements and active vibration isolation elements, which not only increases the difficulty of design and development, but also increases the cost and maintenance complexity of the system. When designing, it is necessary to consider not only the distribution of passive vibration isolation components, but also the installation and arrangement of active actuators 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 vibration 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 relative to the control torque of the center of mass of the load becomes more complicated, resulting in poor adaptability and flexibility between the vibration isolation units, which may lead to poor coordination between different vibration isolation units, thereby affecting the stability and vibration isolation effect of the overall active vibration isolation system. In general, although this modular active vibration isolation system provides flexible control means, its design complexity, energy efficiency issues, cost and maintenance challenges also limit its promotion in certain applications.

[0004] The Chinese patent publication number is CN118224239A, the publication date is June 21, 2024, and the patent name is "A triangular six-degree-of-freedom active vibration isolation platform". The invention patent application discloses a triangular six-degree-of-freedom active vibration isolation platform, including a support base, a load-bearing plate, a connecting plate and a lateral support seat, the lateral support seat is arranged between the support base and the load-bearing plate, and the three lateral support seats are arranged to form a triangular structure. The bottom of the lateral support seat is connected to the support base through a vertical voice coil motor and a high static and low dynamic damping member arranged in parallel, and a connecting plate is vertically arranged between adjacent lateral support seats. The lateral support and the connecting plate are connected one by one, and the lateral support seat is connected to the connecting plate through a horizontal voice coil motor and a spring arranged 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; the invention reduces the number of acceleration sensors and spring actuation components, thereby reducing the time lag problem between sensors, reducing the asynchronism problem between voice coil motors, and improving the active control accuracy of vibration. However, this method places higher demands on the passive vibration isolation design, and the integration of active vibration isolation units makes the design more complicated and the installation more difficult, making it impossible to modify 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 a control method thereof, which can effectively suppress load vibration through multiple inertial mass actuators.

[0006] To achieve the above object, the technical solution created by the present invention is implemented as follows: A control method for an active vibration isolation device is applied to the 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 inertial mass actuator is provided with a feedback sensor correspondingly, so that a plurality of feedback sensors are provided on the load; a plurality of feedforward sensors are provided on the base; the controller is used to execute the control method, and the control method comprises: Obtaining the feedback acceleration collected by the feedback sensor, 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 sensor, and determining the feedforward control force corresponding to each inertial mass actuator according to the feedforward acceleration; The output force of each inertial mass actuator is determined based on the feedback control force and the feedforward control force.

[0007] Furthermore, the feedback acceleration collected by the feedback sensor is obtained, and the feedback control force corresponding to each inertial mass actuator is determined according to the feedback acceleration, including: The feedback control force corresponding to each inertial mass actuator is determined by the following formula:

[0008] 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.

[0009] Further, the feedback acceleration collected by the feedback sensor is obtained, and the feedback control force corresponding to each inertial mass actuator is determined according to the feedback acceleration, which also includes: The transfer function of the feedback controller is determined by the following formula :

[0010] 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.

[0011] Furthermore, the transfer function of the PI controller is determined by the following formula: :

[0012] in, is the acceleration feedback gain, is the absolute speed feedback gain, is the complex frequency variable in Laplace transform; The transfer function of a first-order high-pass filter is determined by the following formula :

[0013] in, is the high-pass cutoff frequency of the feedback controller; The transfer function of a second-order low-pass filter is determined by the following formula :

[0014] 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 :

[0015] 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 :

[0016] 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; .

[0017] Furthermore, the number of feedforward sensors is six, and every two feedforward sensors in the six feedforward sensors form a group to form three feedforward sensor groups, and the three feedforward sensor groups are distributed on the circumference of a circle formed with the center of mass of the base as the center and the radius set value as the radius; wherein one feedforward sensor in one feedforward sensor group collects acceleration in the vertical direction, and the other feedforward sensor collects acceleration in the direction along the tangent of the circle; obtaining the feedforward acceleration collected by the feedforward sensor, and determining the feedforward control force corresponding to each inertial mass actuator according to the feedforward acceleration, including: Obtaining feedforward acceleration collected by a feedforward sensor, integrating the feedforward acceleration collected by multiple feedforward sensors at the center of mass of the base to obtain comprehensive accelerations in six directions at the center of mass of the base; According to the comprehensive acceleration in six directions at the center of mass of the base, the comprehensive control force in six directions at the center of mass of the load is determined; According to the comprehensive control force in six directions at the center of mass of the load, the feedforward control force corresponding to each inertial mass actuator is determined.

[0018] Further, the feedforward acceleration collected by the feedforward sensor is obtained, and the feedforward acceleration collected by multiple feedforward sensors is integrated at the center of mass of the base to obtain the comprehensive acceleration in six directions at the center of mass of the base, including: The combined acceleration in the six directions at the center of mass of the base is determined by the following formula:

[0019] in, It is an array of feedforward acceleration collected by six feedforward sensors. is an array of the integrated accelerations in six directions at the center of mass of the base, The 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, Set a value for the Radius.

[0020] Furthermore, the comprehensive control forces in six directions at the center of mass of the load are determined according to the comprehensive accelerations in six directions at the center of mass of the base, including: The combined control forces in the six directions at the center of mass of the load are determined by the following formula:

[0021] 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 comprehensive 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:

[0022] in, is the damping term feedforward gain, is the stiffness term feedforward gain;

[0023]

[0024] in, p is the cutoff frequency of the weak integrator, is the complex frequency variable in the Laplace transform.

[0025] Furthermore, the feedforward control force corresponding to each inertial mass actuator is determined according to the comprehensive control force in six directions at the mass center of the load, including: The feedforward control force corresponding to each inertial mass actuator is determined by the following formula:

[0026]

[0027] in, is an array of feedforward control forces corresponding to multiple 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 center of mass of the load in the horizontal direction.

[0028] Further, the output force of each inertial mass actuator is determined according to the feedback control force and the feedforward control force, including: The output force of each inertial mass actuator is determined by the following formula:

[0029] in, is an array of output forces of multiple inertial mass actuators, is an array of feedforward control forces corresponding to multiple inertial mass actuators, An array formed by the feedback control forces corresponding to multiple inertial mass actuators.

[0030] An active vibration isolation device is used to execute the control method of the active vibration isolation device as described above.

[0031] Compared with the prior art, the invention can achieve the following beneficial effects: The present invention can add an inertial mass actuator to a passive vibration isolation system composed of a passive vibration isolation unit, thereby adding an active vibration isolation function, and transforming the passive vibration isolation system into an active vibration isolation device with an active vibration isolation function, thereby eliminating the need to set an active actuator such as a voice coil motor in the passive vibration isolation unit, simplifying the design of the passive vibration isolation unit, making the passive vibration isolation unit more compact, and improving the stiffness of the passive vibration isolation unit. 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. The use of an inertial mass actuator is conducive to installation and configuration changes, and has 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 vibration control of the six degrees of freedom of the load, achieve effective suppression of load vibration, reduce the complexity of the mechanical structure, and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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 an active vibration isolation device according to an embodiment of the present invention; Figure 2A schematic diagram of an inertial mass actuator according to an embodiment of the present invention; Figure 3 A force distribution diagram of the inertial mass actuator on the load as described in the embodiment of the invention; Figure 4 A schematic diagram of the distribution of the feedforward sensors on the base according to an embodiment of the present invention; Figure 5 A flow chart of a control method of an active vibration isolation device according to an embodiment of the present invention; Figure 6 The present invention further provides a flow chart of the control method of the active vibration isolation device described in the embodiment of the present invention.

[0033] Description of reference numerals: 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

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0039] See also Figure 1 As shown, the present invention provides an active vibration isolation device 10, which includes a controller for executing a control method of the active vibration isolation device. The controller may adopt a PLC. The controller may include a feedback controller and a feedforward controller, and the feedback controller and the feedforward controller are virtual controllers. The feedback controller may 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 may include a high-pass filter, a lead-lag phase compensation filter, and a notch filter.

[0040] 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 may be a spring damping unit, which may play a supporting role and isolate the vibration of the ground. Figure 1In the illustrated embodiment, there are four passive vibration isolation units 12. The center of mass of the base 13 is arranged corresponding to the center of mass of the load 11, that is, the center of mass of the base 13 and the center of mass of the load 11 are on the same straight line perpendicular to the ground.

[0041] See also 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 may be a spring sheet. The inertial mass block 16 is located in 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, and the mover of the voice coil motor 17 is connected to the inertial mass block 16. 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.

[0042] In one embodiment, each inertial mass actuator 14 is provided with a corresponding feedback sensor 19, so that a plurality of feedback sensors 19 are provided on the load 11. The feedback sensor 19 can collect feedback acceleration, and 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 realize one-to-one ceiling damping control.

[0043] See also Figure 3 As shown, in one embodiment, the direction of the output force of at least one inertial mass actuator 14 among the plurality of inertial mass actuators 14 is in a first direction X, the direction of the output force of at least one inertial mass actuator 14 is in a second direction Y, and the direction of the output force of at least one inertial mass actuator 14 is in a third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. Figure 3 In the embodiment shown in FIG. 1 , the number of the inertial mass actuators 14 is eight, and the directions of the output forces of the two inertial mass actuators 14 are in a first direction X, respectively. , The directions of the output forces of the two inertial mass actuators 14 are in the second direction Y, which are , The directions of the output forces of the four inertial mass actuators 14 are in the third direction Z, which are , , .

[0044] In this embodiment, two factors should be considered when designing the distribution of the inertial mass actuators 14. First, it should be physically feasible so that the eight inertial mass actuators 14 can cooperate with each other to achieve the vibration control of the six degrees of freedom of the load 11. The six degrees of freedom of the load 11 are Figure 3The X-axis direction, Y-axis direction, Z-axis direction, direction around the X-axis, direction around the Y-axis, and direction around the Z-axis are shown in FIG. Secondly, the relative positions of the eight inertial mass actuators 14 in the geometric space are reasonably distributed to reduce the static coupling caused by the distribution method.

[0045] See also 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 the feedforward sensors 20 can be used to resolve the inertial mass actuators 14 for decoupling control. There are six feedforward sensors 20, and each of the six feedforward sensors 20 is a group of two feedforward sensors 20, so as to form three feedforward sensor groups 21. The three feedforward sensor groups 21 are distributed in a circle with the center of mass of the base 13 as the center and the radius set value as the center. On the circumference of a circle with a radius of . Among them, one feedforward sensor 20 in each feedforward sensor group 21 collects acceleration in the vertical direction, and another feedforward sensor 20 collects acceleration in the direction of the tangent of the circle. Figure 4 In the embodiment shown, the feedforward sensor and feedforward sensors As a group, the feedforward sensor and feedforward sensors As a group, the feedforward sensor and feedforward sensors As a group. Among them, the feedforward sensor , , The acceleration and feedforward sensor of the ground perpendicular to the radial and tangential directions of the circle are collected respectively. , , The acceleration in the direction along the tangent of the circle is respectively acquired.

[0046] See also Figure 3 , Figure 4 and Figure 5 As shown, an embodiment of the present invention provides a control method for an active vibration isolation device, which is applied to an active vibration isolation device 10, and the control method includes steps S101-S103.

[0047] In step S101, the feedback acceleration collected by the feedback sensor 19 is obtained, and the feedback control force corresponding to each inertial mass actuator 14 is determined according to the feedback acceleration. The feedback acceleration is the acceleration on the load 11. A feedback controller can be designed accordingly. In this way, the vibration of the active vibration isolation device 10 at the natural frequency can be suppressed to keep the active vibration isolation device 10 stable.

[0048] In one embodiment, step S101 includes: determining the feedback control force corresponding to each inertial mass actuator 14 by the following formula:

[0049] in, 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 , , , , , , , .

[0050] In one embodiment, step S101 further includes: determining the transfer function of the feedback controller by the following formula: :

[0051] 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. The addition of a bandpass 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, and the resonance response of the active vibration isolation device 10 at the natural frequency can be accurately suppressed by adjusting the frequency and bandwidth of the bandpass filter and the notch filter, thereby reducing the influence of the vibration caused by resonance on the active vibration isolation device 10.

[0052] The basis of the feedback controller is the PI controller. In one embodiment, the transfer function of the PI controller is determined by the following formula: :

[0053] in, is the acceleration feedback gain, is the absolute speed feedback gain, is a complex frequency variable in 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.

[0054] In the process of processing the feedback acceleration through the feedback controller, it is necessary to prevent integral drift and saturation of the inertial mass actuator 14. Integral drift refers to the saturation effect 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 by the following formula: :

[0055] in, is the high-pass cutoff frequency of the feedback controller.

[0056] Generally speaking, the smaller the high-pass cutoff frequency of the first-order high-pass filter, the smaller the phase advance of the passband, and the better the integrator performance. However, at the same time, the smaller the frequency, the more likely it is that the integral saturation of the feedback controller and the stability of the high-pass filter will deteriorate. The use of 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, in order to achieve frequency band control, the feedback controller actively controls only in the low frequency band, which will not affect the high-frequency mode, and can suppress the influence of the high-frequency noise in the acceleration acquisition process of the feedback sensor 19 on the active vibration isolation device, and a second-order low-pass filter is added. The transfer function of the second-order low-pass filter is determined by the following formula: :

[0057] in, is the low-pass cutoff frequency of the feedback controller.

[0058] The introduction of a first-order high-pass filter and a 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, which is prone to oscillation. In order to ensure the stability and phase margin of the feedback controller, a lead-lag phase compensation filter needs to be added to the control of the feedback controller. The transfer function of the lead-lag phase compensation filter is determined by the following formula: :

[0059] Where K is the gain of the lead-lag phase compensation filter, is the frequency of the pole, The frequency of zero point.

[0060] In order to suppress the influence of the noise generated by the 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: :

[0061] 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. .

[0062] In step S102, the feedforward acceleration collected by the feedforward sensor 20 is obtained, and the feedforward control force corresponding to each inertial mass actuator 14 is determined according to the feedforward acceleration. The feedforward acceleration is the acceleration of the base 13, that is, the acceleration of the ground. A feedforward controller can be designed accordingly. The use of a feedforward controller can effectively expand the vibration isolation bandwidth of the active vibration isolation device 10.

[0063] See also Figure 3 , Figure 4 and Figure 6 As shown, in one embodiment, step S102 includes steps S201 to S203.

[0064] In step S201 , the feedforward acceleration collected by the feedforward sensor 20 is acquired, and the feedforward accelerations collected by multiple feedforward sensors 20 are integrated at the center of mass of the base 13 to obtain the comprehensive accelerations in six directions at the center of mass of the base 13 .

[0065] In one embodiment, step S201 includes: determining the integrated acceleration in six directions at the center of mass of the base 13 by the following formula: The acceleration of the base 13 can be expressed as:

[0066]

[0067] in, is an array formed by the feedforward acceleration collected by six feedforward sensors 20, , is an array formed by the integrated accelerations in six directions at the center of mass of the base 13, , is a conversion matrix of the feedforward acceleration collected by each feedforward sensor 20 to the comprehensive acceleration in six directions at the center of mass of the base 13, is the radius setting value. Among them, the array formed by the integrated acceleration in six directions at the center of mass 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 base 13 The acceleration in the direction, Represents base 13 The acceleration in the direction, Represents base 13 The acceleration in the direction. The direction is around the X axis. The direction is around the Y axis. The direction is around the Z axis.

[0068] In step S202 , the comprehensive control forces in the six directions at the center of mass of the load 11 are determined according to the comprehensive accelerations in the six directions at the center of mass of the base 13 .

[0069] In one embodiment, step S202 includes: determining the comprehensive control forces in six directions at the center of mass of the load 11 by the following formula:

[0070] in, is the transfer function of the feedforward sensor 20, is an array formed by the integrated accelerations in six directions at the center of mass of the base 13, is an array formed by the comprehensive control forces in six directions at the center of mass of the load 11, are the forces in three directions at the center of mass of load 11, are the moments in three directions at the center of mass of load 11. ; .in, 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.

[0071] Transfer function of feedforward controller for:

[0072] in, is the damping term feedforward gain, The damping term feedforward gain can cancel the vibration transmission of the damping term of the active vibration isolation device 10 , and the stiffness term feedforward gain can cancel the vibration transmission of the stiffness term of the active vibration isolation device 10 .

[0073]

[0074]

[0075] Where p is the cutoff frequency of the weak integrator, is the complex frequency variable in the Laplace transform. Since the weak integrator has its own low-pass filtering effect, there is no need to add an additional low-pass filter. In addition, as with the feedback controller, in order to avoid the phase delay of the feedforward controller and the influence of the high-frequency mode of the feedforward controller, a lead-lag phase compensation filter can be added and notch filters .

[0076] In step S203 , the feedforward control force corresponding to each inertial mass actuator 14 is determined according to the comprehensive control forces in six directions at the mass center of the load 11 .

[0077] In one embodiment, step S203 includes: determining the feedforward control force corresponding to each inertial mass actuator 14 by the following formula:

[0078]

[0079] in, is an array formed by the feedforward control forces corresponding to the multiple inertial mass actuators 14. In this embodiment, the number of the inertial mass actuators 14 is eight. , that is, the feedforward control forces corresponding to the eight inertial mass actuators 14 can be expressed as , , , , , , , . is the conversion matrix of the feedforward control force corresponding to the inertial mass actuator 14 to the comprehensive control force in six directions at the center of mass of the load 11, are the forces in three directions at the center of mass of load 11, are the moments in three directions at the center of mass of load 11, is the distance from the inertial mass actuator 14 to the mass center of the load 11 in the vertical direction, is the distance from the inertial mass actuator 14 to the mass center of the load 11 in the horizontal direction.

[0080] In step S103 , the output force of each inertial mass actuator 14 is determined based on the feedback control force and the feedforward control force.

[0081] In one embodiment, step S103 includes: determining the output force of each inertial mass actuator 14 by the following formula:

[0082] in, An array formed by the output forces of a plurality of inertial mass actuators 14, is an array formed by the feedforward control forces corresponding to the multiple inertial mass actuators 14, An array is formed by the feedback control forces corresponding to the multiple inertial mass actuators 14 .

[0083]

[0084]

[0085]

[0086] The present invention can add an inertial mass actuator 14 to a passive vibration isolation system composed of a passive vibration isolation unit, thereby adding an active vibration isolation function, and transforming the passive vibration isolation system into an active vibration isolation device 10 with an active vibration isolation function, so that there is no need to set an active actuator such as a voice coil motor in the passive vibration isolation unit 12, and the design of the passive vibration isolation unit 12 can be simplified, so that the passive vibration isolation unit 12 can be designed to be more compact, and the stiffness of the passive vibration isolation unit 12 can be improved. It can be applied to an active vibration isolation device 10 with a high natural frequency, has a strong anti-interference characteristic, and ensures the ability to suppress the internal disturbance of the load 11 when the active vibration isolation device 10 has a high stiffness and natural frequency. And the use of the inertial mass actuator 14 is conducive to installation and configuration change, and has stronger adaptability. At the same time, after the center of mass of the load 11 changes, the installation position of the inertial mass actuator 14 can be adjusted accordingly to achieve vibration control of the six degrees of freedom of the load 11, and effectively suppress the vibration of the load 11, reducing the complexity of the mechanical structure and reducing the cost.

[0087] 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.

[0088] 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 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 correspondingly provided with a feedback sensor, so that a plurality of the feedback sensors are provided on the load; A plurality of feedforward sensors are arranged on the base; The controller is used to execute the control method, which includes: 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; Acquire the feedforward acceleration collected by the feedforward sensor, and determine the feedforward control force corresponding to each of the inertial mass actuators according to the feedforward acceleration; 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: The number of the feedforward sensors is six, and every two of the six feedforward sensors form a group to form three feedforward sensor groups, and the three feedforward sensor groups are distributed on the circumference of a circle formed with the center of mass of the base as the center and the radius set value as the radius; wherein one feedforward sensor 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 obtaining of the feedforward acceleration collected by the feedforward sensor and determining the feedforward control force corresponding to each of the inertial mass actuators according to the feedforward acceleration includes: Acquire the feedforward acceleration collected by the feedforward sensor, and integrate the feedforward accelerations collected by the multiple feedforward sensors at the center of mass of the base to obtain the comprehensive accelerations in six directions at the center of mass of the base; 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; The feedforward control force corresponding to each of the inertial mass actuators is determined according to the comprehensive control forces in six directions at the mass center of the load.

6. The control method of the active vibration isolation device according to claim 5, characterized in that: The step of acquiring the feedforward acceleration collected by the feedforward sensor and integrating the feedforward accelerations collected by the multiple feedforward sensors at the center of mass of the base to obtain the comprehensive accelerations in six directions at the center of mass of the base includes: The combined acceleration in the six directions at the center of mass of the base is 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, Set a value for the radius.

7. The control method of the active vibration isolation device according to claim 5, 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.

8. The control method of the active vibration isolation device according to claim 5, 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.

9. 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.

10. An active vibration isolation device, characterized in that: A control method for executing an active vibration isolation device as described in any one of claims 1 to 9.

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