CN-121721970-B - Control method, system, equipment and medium of active vibration isolation system of precision equipment

CN121721970BCN 121721970 BCN121721970 BCN 121721970BCN-121721970-B

Abstract

The embodiment of the invention provides a control method, a control system, a control device and a control medium of an active vibration isolation system of precision equipment, belonging to the crossing field of vibration control and intelligent control of the precision equipment. By constructing a novel vector type direct barrier function, the physical hard constraint of the system output is equivalently converted into the bounded requirement of the variable in the transformation space, so that the method is more direct and universal. The unknown nonlinear dynamics appearing in the back-stepping design are approximated in parallel by adopting a distributed fuzzy logic system network, and the calculation complexity is greatly reduced by only on-line adjustment of the square of the weight vector norm. In the recursive design of the backstepping control law, a hyperbolic tangent function and a projection operator are integrated, so that the amplitude values of the virtual control law and the actual control law have a priori known upper bound, thereby meeting the input saturation constraint and realizing the internal saturation design of the controller.

Inventors

LIU SHUAI
Wang sanxia
ZHANG QIAN
BU SHI
WANG JUNJIE

Assignees

山东大学
北京半导体专用设备研究所（中国电子科技集团公司第四十五研究所）

Dates

Publication Date: 20260512
Application Date: 20260225

Claims (6)

1. A control method of an active vibration isolation system of precision equipment, comprising the following steps: establishing a strict feedback type nonlinear model of the active vibration isolation system; Constructing an obstacle function related to displacement of a vibration isolation platform in an active vibration isolation system to translate physical output constraints of the vibration isolation platform displacement into an bounded control target of the obstacle function; Approximating an unknown nonlinear vector function in the strict feedback form nonlinear model by adopting a fuzzy logic system; Based on a back-stepping method, combining a hyperbolic tangent function and a projection operator, recursively designing a virtual control law and an actual control law, and ensuring that a control instruction is always within physical saturation limits of an actuator in an active vibration isolation system, wherein the virtual control law and the actual control law are provided with a priori determined upper bound by introducing the hyperbolic tangent function and utilizing the projection operator to carry out bounded correction on a parameter estimation value of a fuzzy logic system, so that the input saturation constraint of the active vibration isolation system is satisfied; the self-adaptive law of the parameter is designed and used for updating the parameter estimation value of the fuzzy logic system on line and ensuring the pertinence of the parameter estimation value in the updating process by utilizing a projection operator; Wherein the barrier function is as follows: ; In the formula, For the output of the active vibration isolation system, And The lower and upper bounds of the output are respectively; approximation of unknown nonlinear vector functions using fuzzy logic systems The approximation form is as follows: ; In the formula, As the vector of the ideal weight values, In order to blur the basis function vector, Is a bounded approximation error; Virtual control law No. The components are as follows: ; In the formula, In order to control the gain of the gain control, For a positive design parameter to be adjustable, As a variable of the error it is possible to provide, For parameter norm estimation by an adaptive law with projection, In order to blur the basis function vector, Comprising known coupling terms and reference signal differentiation terms, As a hyperbolic tangent function; actual control law First, the The components are as follows: ; In the formula, In order to control the gain function, For a positive design parameter to be adjustable, Is the first The error variable of the step is used to determine, For parameter norm estimation by an adaptive law with projection, In order to blur the basis function vector, As a hyperbolic tangent function.
2. The method for controlling an active vibration isolation system of precision equipment according to claim 1, wherein the strict feedback form nonlinear model is expressed as: ; ; ; In the formula, A system state vector configured for a plurality of vibration isolation unit states, In order to control the input vector(s), In order to output the vector quantity, Is a known non-singular control gain matrix, As an unknown function of a continuous nonlinear vector, For a time-varying unknown disturbance vector, the output constraint is defined as: , wherein, Representing the individual inequalities of the vector elements, For the lower bound vector of the constraint, Is the upper bound vector.
3. The control method of the precision equipment active vibration isolation system according to claim 1, wherein the parameter estimation value is updated on line according to the following formula: ; In the formula, For the parameter estimation value of the K-th time, In order to sample the time of the sample, As a function of the adaptation of the function, For the projection operator, Is an adaptive gain.
4. A control system of a precision equipment active vibration isolation system applied to the control method of a precision equipment active vibration isolation system according to any one of claims 1 to 3, characterized by comprising: The model building unit is used for building a strict feedback type nonlinear model of the active vibration isolation system; A function construction unit configured to construct an obstacle function so that an output constraint is converted into a constraint requirement of the obstacle function; The function approximation unit is used for approximating an unknown nonlinear vector function in the nonlinear model in the strict feedback form by adopting a fuzzy logic system; The control law design unit is used for designing a bounded virtual control law and an actual control law by combining a back-stepping method, a hyperbolic tangent function and a projection operator, and ensuring that a control instruction is always within the physical saturation limit of an actuator in the active vibration isolation system, wherein the virtual control law and the actual control law have a priori known upper bound by introducing the hyperbolic tangent function and combining the projection operator to carry out bounded correction on the parameter estimation value of the fuzzy logic system, so that the input saturation constraint of the active vibration isolation system is met; and the parameter updating unit is used for designing a parameter self-adaptive law, updating the parameter estimation value on line and ensuring the bouncy of the parameter estimation value by utilizing a projection operator.
5. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor, when executing the program, implements the steps of the control method of the precision equipment active vibration isolation system according to any one of claims 1 to 3.
6. A storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, realizes the steps of the control method of the precision equipment active vibration isolation system according to any one of claims 1 to 3.

Description

Control method, system, equipment and medium of active vibration isolation system of precision equipment Technical Field The invention relates to the technical field of intersection of vibration control and intelligent control of precision equipment, in particular to a control method, a control system, control equipment and control media of an active vibration isolation system of the precision equipment. Background With the rapid development of high-end manufacturing, integrated circuits, biological medicine and other fields, the requirements of precision equipment (such as a scanning electron microscope, an atomic force microscope, a precision numerical control machine tool and the like) on working environments are increasingly stringent. The small mechanical vibration can lead to reduced machining precision, reduced product yield and even direct equipment failure. The active vibration isolation system is a key technology for guaranteeing the stability of the working environment of precision equipment by detecting vibration in real time and applying reverse control force. However, control design of precision equipment active vibration isolation systems presents multiple challenges: Damping and rigidity in the vibration isolation system often show nonlinear characteristics, and system parameters can change along with load, service life and environmental temperature, so that accurate modeling is difficult. At the same time, the system is also affected by external unknown disturbances from the ground, personnel operations, etc. Stringent output constraints-for safety and performance considerations, the displacement of the vibration isolation platform must be severely limited within a safe physical range. For example, excessive displacement may cause the precision apparatus to collide with the surrounding structure, or cause the actuator to go beyond its effective stroke, resulting in irreversible damage. Inherent input saturation is that the output force of actuators (such as voice coil motors and piezoelectric actuators) in the system has a physical upper limit and cannot provide infinite control force. If the influence of the saturation nonlinearity is ignored in the design of the controller, the system performance degradation and even instability are easily caused. The high requirement on control performance is that not only is the stability of the system ensured, but also the system output is required to be capable of quickly and accurately tracking the desired reference track (usually zero displacement or a specific track) and has good dynamic quality. Traditional control methods, such as classical PID control, perform well in handling linear, steady-state systems, but are difficult to handle efficiently the above-described nonlinearities, constraints, and uncertainties simultaneously. Although the existing back-step control, self-adaptive control and method based on the barrier Lyapunov function have made certain progress in theory, in practical application, the problems of complex structure, heavy calculation load, failure to simultaneously consider output constraint and input saturation and the like often exist in the controller. Therefore, there is an urgent need for a practical and robust control scheme that systematically addresses all of the above challenges. Disclosure of Invention The embodiment of the invention aims to provide a control method, a control system, a control device and a control medium for an active vibration isolation system of precision equipment, which can ensure that the displacement output of a vibration isolation platform does not violate preset constraint all the time on the premise of not depending on an accurate system model, the control input is always positioned in the physical saturation limit of an actuator, the control input is known as priori knowledge, the system is consistent and finally bounded on all closed loop signals, and excellent reference signal tracking performance is realized. In order to achieve the above object, an embodiment of the present invention provides a control method of an active vibration isolation system for precision equipment, including: establishing a strict feedback type nonlinear model of the active vibration isolation system; Constructing an obstacle function related to displacement of a vibration isolation platform in an active vibration isolation system to translate physical output constraints of the vibration isolation platform displacement into an bounded control target of the obstacle function; Approximating an unknown nonlinear vector function in the strict feedback form nonlinear model by adopting a fuzzy logic system; based on a back-stepping method, combining a hyperbolic tangent function and a projection operator, recursively designing a virtual control law and an actual control law, and ensuring that a control instruction is always within a physical saturation limit of an actuator in an active vibration isolation system, whe