Simulation and parameter extraction of flying-bird motion echo based on laser micro-Doppler effect

To solve the problem of target recognition for flying-birds and biomimetic flapping-wing unmanned aerial vehicles (UAVs), a rectangular-trapezoidal composite scattering model for lidar detection of bird wings has been proposed and established. According to the model, the influence of different line-of-sight angles on the time–frequency distribution characteristics of laser micro-Doppler under the same flapping wing motion was simulated and studied. Then, the flapping-wing frequency and maximum frequency shift are extracted based on the two-dimensional Fourier transform and the least squares method. When signal noise ratio = 5 dB, the accuracy rate of flapping-wing frequency extraction can reach at 100%, the maximum relative error of frequency shift for inner contour extraction is less than 3.0%, and the maximum relative error of frequency shift for outer contour extraction is less than 7.2%.