Linear and Nonlinear stabilizing control of Quadrotor UAV

Quadrotor Unmanned Ariel Vehicles (UAVs) are commonly used for complex tasks such as, surveillance, search and rescue in hazard locations for its small size, lightness and robustness. However, the stability of UAVs represents a big challenge due to its high Nonlinear, multivariable, strongly coupled nature. The present work investigates two commonly-used control strategies namely, PD-control with low pass filter and Nonlinear feedback linearization control. The parameters of each controller are optimized to set the time-domain performance within specific constrains. The performances of the two control strategies are simulated and the results are validated on real experiments. The results indicate that Nonlinear control can substantially expand the region of controllable flight angles compared to linear control. It can stabilize the quadrotor system in case of multi angle disturbances. PD-controller with low passes filter shows poor performance when it synchronously controls more than one angle at the same time.