Method for determining order of unknown model based on traversing and identification of genetic algorithm

Abstract

The invention discloses a method for determining the order of an unknown model based on the traversing and identification of a genetic algorithm, and belongs to the technical field of undetermined system identification modeling. The method is characterized by comprising three stages of initial setting, increasing identification and order determination, wherein the initial setting stage is used for setting the search range of the unknown model order and comprises three steps of acquiring frequency domain response data, setting an upper limit and a lower limit for the model order and initializing the order; the increasing identification stage is used for searching for and identifying all model structures in the set stage and comprises three steps of identifying by the genetic algorithm, recording the identification results and increasing the order; and the order determination stage is used for finding the optimal model structure by a cost function and comprises two steps of optimizing by the cost function and determining order combinations, wherein through the three stages, all possible order combinations of the unknown model can be traversed and identified, each order combination is approached to the greatest degree by using the genetic algorithm, and then the order combination corresponding to the minimum cost function is found from the identification results so that the order of the unknown model can be determined. In the method, the genetic algorithm is used to perform order traversing system identification on the frequency domain response data of the unknown model and find the model structure approaching the experimental data most, and thus, the order of the unknown model is determined by using experimental data and an optimizing means.

Description

technical field [0001] The invention is a method for determining the order of the unknown model, which can accurately determine the order of the unknown model by relying on experimental data. It is mainly used in uncertain systems, aerospace, robotics and other technical fields. Background technique [0002] Determining the order of the unknown system is a key step in modeling the unknown system and analyzing the dynamic characteristics. The previous method of determining the order is usually mechanism analysis, and adopts means such as simplification and approximation to obtain the approximate order. However, for some complex systems, it is difficult and urgent to determine the order of its dynamic model accurately. Taking helicopters and tiltrotors as examples, their manipulation, power system and working conditions are very complicated. Not only that, the surface of this type of aircraft in its various flight states is usually a turbulent flow field that changes at any...

AI Technical Summary

Problems solved by technology

The flow field has a great influence on the dynamic model, but there is no effective means to quantify the influence of the flow field

Therefore, it is difficult to accurately and effectively determine the model order by using the mechanism modeling method

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