PID plus LQR attitude control for hexarotor MAV in indoor environments

The aim of this paper is to propose an optimum linear control algorithm that is able to stabilize the attitude of a hexarotor micro aerial vehicle (MAV) in indoor environment. The work will then compare it with the classical control PID (proportional-integral-derivative) and optimal control LQR (linear quadratic regulator) techniques. The proposed attitude controller is based on an outer-inner loop structure PID plus LQR (PID+LQR) control method where the controller combines the positive features of each sub-controller (PID and LQR). The key contribution of this work is the proposed attitude controller can improve robustness and transient response thus leads to faster response in indoor flying environment. The attitude tracking errors are proven to be ultimately bounded with specified boundaries. Simulation results on the hexarotor demonstrate the effectives of the proposed attitude controller.