Magnetic levitation bearing robust controller construction method based on multi-objective genetic algorithm

Abstract

The invention belongs to the electrical control technology field, relates to the robust control technology field and especially relates to a magnetic levitation bearing robust controller constructionmethod based on a multi-objective genetic algorithm. The method is characterized by summarizing the general formula of a robust controller weight matrix function and limiting the range of a weight function parameter; and giving the adjustment direction of manual weight parameter adjustment, and solving the blindness of a beginner choosing a robust controller weight function. In the invention, a multi-objective genetic algorithm is further adopted to optimize the weight function parameter and a designer can compromise between closed loop response performance and a control signal according to anactual demand so as to acquire an optimal robust H-infinite controller under two objectives. A user does not need to grasp excess professional knowledge and can easily and reasonably construct the robust H-infinite controller suitable for an axial (a single degree of freedom) magnetic levitation bearing system.

Description

technical field [0001] The invention belongs to the technical field of electrical control, specifically relates to the technical field of robust control, in particular to a method for constructing a robust controller of a magnetic suspension bearing based on a multi-objective genetic algorithm. Background technique [0002] As a key component of the superfluid helium cryogenic refrigeration system, the cold compressor is used to pump and depressurize the saturated liquid helium tank under low temperature negative pressure to obtain superfluid helium. At present, the centrifugal cold compressor independently developed by the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences has a speed of up to 60,000 rpm, which puts higher requirements on the supporting parts of the compressor rotor. The magnetic levitation bearing suspends the rotor in the space by generating electromagnetic force, realizing the non-contact between the stator and the rotor and ...

AI Technical Summary

Problems solved by technology

However, the technical difficulty in constructing a robust H∞ controller lies in the selection of the weight function

[0004] Regarding how to select the appropriate weight function of the robust controller, the existing technologies are mainly divided into two types. The first commonly used method is based on some qualitative characteristics of the three weight functions. Engineers try and iterate repeatedly. This method Requires a lot of experience, especially for novices, it is time-consuming and laborious

The second relatively new technology is to optimize the weight function based on a heuristic algorithm, but the current technology uses a single fitness function, so that only a certain goal can be obtained, such as a robust controller under tracking performance

The problem is that for magnetic suspension bearings, not only the response performance of the closed-loop system needs to be good, but also the control signal needs to be small, that is to say, the input current of magnetic suspension bearings should not be too large

Because the magnetic suspension bearing itself is nonlinear, if the control signal is large, the current will exceed the linearization range of the hysteresis loop, resulting in magnetic field saturation and control failure.

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