Unmanned aerial vehicle target rotor parameter estimation method based on scattering transformation

Abstract

The invention discloses an unmanned aerial vehicle rotor parameter estimation method based on a linear frequency modulation continuous wave radar. The method comprises the steps of 1, initializing a scattering transformation scale, and generating a wavelet filter bank; 2, performing first-order scattering transformation on the echo signal; 3, setting an energy threshold value for the scattering coefficient, carrying out second-order scattering transformation, and estimating a spectral bandwidth; 4, extracting a second-order scattering coefficient where the micro-Doppler component is located, extracting a periodic component to carry out FFT (Fast Fourier Transform) to obtain a frequency spectrum, and judging the number of rotors according to the number of frequency components; 5, if the number of the rotors of the unmanned aerial vehicle is 0 determining that the rotors do not exist, and skipping to 8, otherwise, entering 6; 6, estimating the rotation frequency according to the number N of the rotors and the peak interval frequency; 7, reversely deducing the size of the blade by combining the micro-motion spectral bandwidth and the rotation frequency; and 8, outputting a rotor parameter estimation result. According to the invention, the linear frequency modulation continuous wave radar can estimate the rotating speed, the number and the size of the unmanned aerial vehicle target rotor.

Description

technical field [0001] The technical field to which the invention belongs; specifically relates to a method for estimating parameters of an unmanned aerial vehicle target rotor based on scattering transformation. Background technique [0002] As the scale of commercial drone use grows, the safety issues caused by the misuse of drones are getting more and more attention. At present, there are many methods to detect UAV targets. Compared with other methods, the radar system has the advantages of all-weather, all-time, and long detection distance. The linear frequency modulation continuous wave radar has the advantages of simple structure, high resolution, no distance blind zone, etc. The advantage is to replace the pulse system radar, which can be used as an important means of detecting short- and medium-range low-altitude UAVs. However, since UAV targets are generally small in size, slow in movement speed, and low in flying height, they are easily confused with flying birds ...

AI Technical Summary

Problems solved by technology

[0004] However, under normal circumstances, the rotor length of small UAVs is relatively small, generally at the sub-meter level, resulting in low micro-Doppler component energy, and relatively fast speed, generally thousands of revolutions per minute, resulting in large The Doppler frequency broadening makes it difficult to extract parameters

Moreover, the interaction between the rotor blades will generate high-order harmonic components of the rotation frequency in the echo, which will interfere with the estimation of the rotation frequency

[0005] The existing methods are mainly linear time-frequency analysis, such as short-time Fourier transform, the time resolution and frequency resolution are mutually restricted, which limits the effect of energy accumulation and reduces the estimation effect of rotation frequency. Some bilinear Although time-frequency analysis such as Cohen's method has improved the energy accumulation effect, there is a problem of cross-terms for multi-component signals, and the existing methods will be affected by the echo of the main body, so it is difficult to estimate the rotor parameters

[0006] Due to the above reasons, the traditional non-stationary signal analysis method is not suitable for the estimation of UAV rotor parameters

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