The altitude control of a quadrotor unmanned aerial vehicle is treated using its altitude dynamics in hover mode. An LMS-based Adaptive Active disturbance rejection control (AADRC) is proposed to compensate for disturbance effects resulting in smoother control.
An LMS algorithm for the adaptation of the observer gain was presented to automatically tune the ESO observer. The ESO observer linearizes the altitude dynamics. Subsequently, a PD controller was implemented for the linearized dynamics and was successfully simulated in Matlab
The Altitude dynamics of a Quadrotor is given as follows:
Formulation of the ADRC Controller:
Formulation of the AADRC Controller using LMS:
The figure below shows the result of applying the AADRC for Altitude control
