Structural optimization and stability analysis of the ducted fan unmanned aerial vehicles

This article investigates the improvement of dynamics stability of the ducted fan unmanned aerial vehicles(UAVs) by optimizing its mechanical-structure parameters. The instability phenomenon of the ducted fan unmanned aerial vehicles takes place frequently that easily leads to vibration and even out of control, due to complicated airflow. The dynamics equations mirror its dynamics characteristics, which is primarily influenced by the mechanical-structure parameters of the whole system. Based on this, the optimization of mechanical-structure parameters will improve the dynamics stability of the whole system. Therefore, this paper uses the concept of Lyapunov exponents to build the quantification relationship between system’s mechanical-structure parameters and its motion stability to enhance its stability. The simulation experimental results indicate that compared with the direct Lyapunov method, the most important advantage of the proposed method is its constructivity, so it is an effective tool for analysis of the motion stability of other non-linear systems such as robots.