An Automatic Decision Algorithm for Foreign Objects Debris Based on Duffing Oscillator

The Foreign Objects Debris ( FOD) detection technology based on millimeter wave radar has the advantages of high resolution and low power consumption, but the traditional Constant False Alarm Rate (CFAR) detection algorithm has high false alarm probability under the condition of low Signal-to-Clutter Ratio (SCR). A FOD detection method based on Duffing oscillator is proposed. In this method, the clutter map CFAR detection method is firstly used to separate the background clutter from the received echo signal in the radar receiver, after that the distance information of target (including false alarm) can be acquired, and the Duffing equations are constructed by using the distance information. Then the Duffing equations are used as the system detection model, and the received echo signal is considered as the input. Therefore, the output variance can be calculated by solving the Duffing equations. Finally the target can be distinguished from the false alarm by using the variance extremum method. Simulation results show that, even if the false alarm probability is 10(-3), the detection method in this paper can distinguish the target from the false alarm automatically under the condition of low SCR. Furthermore, it can also reduce the false alarm probability. Compared with the traditional CFAR detection algorithm, the detection probability of this method is higher and reduces more slowly with the decrease of SCR. Meanwhile, the detection probability can be maintained at 84% under the condition of SCR=-30 dB.