Robust Motion Control of Nonlinear Quadrotor Model With Wind Disturbance Observer

Abstract

This paper focuses on robust wind disturbance rejection for nonlinear quadrotor models. By leveraging on nonlinear unknown observer theory, it proposes a nonlinear dynamic filter that, using sensors already on-board the aircraft, can estimate in real-time wind gust signals in the three dimensions. The wind disturbance is then treated as input to the PD controller for a quick and robust flight pathway in presence of disturbances. With this scheme, the wind disturbance can be precisely estimated online and compensated in real-time. Hence, the quadrotor can successfully reach its desired attitude and position. To show the effective and desired performance of the method, simulation results are presented in Matlab/Simulink and ROS-enabled Gazebo platform.

Frequency-Based Wind Gust Estimation for Quadrotors Using a Nonlinear Disturbance Observer

“…In the developed NDOB, the desired cut-off frequency is set by designing a circular region that bounds the condition for choosing the observer gain. Furthermore, compared with other DOB-based methods [19], [20], the developed NDOB approximates the usual twelfth-order nonlinear model to a sixth-order model. This significantly reduces the computational cost.…”

“…The obtained results had a high convergence rate owing to high gain. An unknown input observer (UIO), similar to the ESO, was used in [20]. However, the utilization of high gains resulted in overshooting.…”

“…In, [20], they suggested that the wind gusts are mainly horizontal and only affect the x and y dynamics substantially. Whereas, the present study considers all the effects on the states, including the orientation states, demonstrating the generality and simplicity of the present approach.…”

Improved Performance in Quadrotor Trajectory Tracking Using MIMO PIλ-D Control

“…The performance index depends on the tracking error and the quadrotor inputs to reduce the power consumption of the quadrotor [20]. [21] designed the robust system with the unknown input observer and PD-based precise trajectory control of quadrotor in the presence of wind gusts.…”