Modeling method of multi-rotor aircraft transfer function model based on frequency domain identification

Abstract

The invention discloses a multi-rotor aircraft transfer function model modeling method based on frequency domain identification. The method automatically generates frequency sweep signals through the flight control unit for flight tests, and obtains a database for non-parametric identification and transfer function identification in the frequency domain; Then the spectrum estimation is performed on the flight data, and the frequency response of the channel to be identified is calculated; finally, the transfer function model of the multi-rotor aircraft is identified and verified by the frequency domain output error method. This method can well adapt to the unstable characteristics of multi-rotor aircraft, and the identification process is simple; the method of identifying the flight dynamics model of multi-rotor aircraft in the frequency domain of the transfer function model can efficiently obtain high-confidence models for different types of UAVs. The test period is within 2 days and can be verified repeatedly. It does not need to invest a lot of research and development costs in wind tunnel tests to obtain aerodynamic derivatives like the existing technology. Compared with the existing technology, it saves a lot of time and economic costs, and has higher reliability. high.

Description

technical field [0001] The invention relates to a multi-rotor aircraft transfer function model modeling method, in particular to a multi-rotor aircraft transfer function model modeling method based on frequency domain identification; it belongs to the technical field of multi-rotor aircraft flight dynamics modeling. Background technique [0002] A high-confidence flight dynamics model is an important basis for multi-rotor aircraft flight control design, flight quality assessment, and controller performance optimization. In the traditional mechanism modeling work, the main difficulty lies in the establishment of the aerodynamic model and the calculation of the moment of inertia. Since the aerodynamic characteristics of multi-rotor aircraft are more complex, it takes a lot of time and effort to establish high-precision flight dynamic characteristics. Wind tunnel test is one of the means to establish a highly accurate flight dynamics model, but it requires high research and de...

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Problems solved by technology

[0004] However, the traditional time-domain identification algorithm needs to identify the noise model. Regardless of the output error method or the equation error method, if the noise is ignored, it will bring deviations to the identification results, and the amount of data that needs to be processed is large.

The traditional time-domain identification algorithm needs to numerically solve the differential equation of multi-rotor aircraft flight dynamics. Due to the inherent instability of multi-rotor aircraft and the error of experimental data, it is very likely that the error of the solution result is too large or divergent, which leads to the failure of identification.

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