In order to suppress the relative intensity noise (RIN) of broadband light source-based resonant fiber optic gyroscope (RFOG) and improve the accuracy of RFOG. The structure of the fiber optic resonant cavity sensitive element is analyzed and optimized. First, a simulation model is established based on the multi-loop interference superposition theory to explore the transmission characteristics of the broadband RFOG under different sensitive element structures. Next, based on the RFOG optical field theoretical model, the impact of coupler position on the accuracy of the gyroscope and the magnitude of the RIN is analyzed. Experimental results show that the asymmetric resonator with the fiber loop at the coupler's cross port achieves superior accuracy. And this structure suppresses relative intensity noise. By optimizing the sensitive element structure and using a fiber resonator with a diameter of 10 cm and a length of 220 meters, the angle random walk reached and the bias instability reached 0.002 (°)/h. In addition, a single-axis gyroscope prototype is built using a fiber loop with a diameter of 5 cm and a length of 300 meters. The prototype has a volume of 170 cm³. the angle random walk reachedand the bias instability reached 0.02(°)/h.

To improve the trajectory tracking accuracy and rapidity of quadrotor unmanned aerial vehicles under multi-source interference, a composite global non-singular fast terminal sliding mode control method is proposed. Firstly, the characteristics of the position and attitude loop of the quadrotor UAV are fully considered and divided into four independent channels to convert them into cascade channels. Secondly, the expanded state observer is adopted to estimate the lumped interference (coupling terms and external disturbances in each channel) and state information. Based on the estimated information, a composite global non-singular fast terminal sliding mode control method is designed, and the saturation function is used instead of the sign function to ensure the continuity of the control quantity. Finally, the simulation results show that compared with the traditional PID, active disturbance rejection control, and non-singular fast terminal sliding mode control schemes, the proposed control schemes are 76.3%, 62.7% and 74.4% higher, verifying that the proposed control schemes have higher trajectory tracking accuracy and anti-disturbance.