A hybrid controller based on feedforward compensator and PSO-aided SCPID for quadrotor UAV

Considering that quadrotor unmanned aerial vehicles (UAVs) often encounter unknown disturbance caused by model parameter perturbations and environmental changes, a novel hybrid controller based on feedforward compensation and particle swarm optimization-aided self-coupling proportional-integral-derivative (FC-PSO-SCPID) is proposed for quadrotor UAVs through the outer loop (position) control and the inner loop (attitude) control. In the proposed controller, feedforward compensator is introduced to compensate for the hysteresis effect on a certain independent variable (disturbance) using the inverse model. Hence, the tracking speed and accuracy are dramatically improved, and the output can reach the preset value instantly. In SCPID controller, the speed factor is difficult to obtain automatically, and thus the particle swarm optimization (PSO) is introduced to adjust the parameters by using the integrated time absolute error (ITAE). Moreover, the stability analysis for the closed-loop systems of both the position and attitude of the quadrotor UAV system was proved by Hurwitz stability criterion. Extensive simulations conducted in MATLAB/Simulink show that the FC-PSO-SCPID controller outperforms conventional methods in terms of response speed, steady-state accuracy, and anti-disturbance ability. Specifically, the convergence time and steady-state error of the proposed controller are less than 1.5 s and 1%, respectively. In addition, the situation of stability failure has also been discussed.