Optimised fractional order PID controller for a 3 DOF Hover quadrotor: experimental validation and robustness analysis

This paper aims to implement a model-free linear control law based on fractional proportional integral derivative (FPID) regulator. The control approach is applied to a quadrotor system to stabilise its attitude through the three rotation axes (roll, pitch, and yaw), where the control parameters are optimised via the particle swarm optimisation (PSO) algorithm. The proposed controller is tested in simulation, experimentally validated on the 3DOF Hover platform, and compared with two other methods: the linear quadratic regulator (LQR), the classical proportional integral derivative (PID) controller and the Backstepping method. Furthermore, robustness analysis is carried out to evaluate the performances of the investigated controller against internal and external disturbances. The obtained results have demonstrated the efficiency and usefulness of the investigated controller in terms of precision (less than 0.2 degrees in attitude error) and robustness in the presence of perturbed environments.