Evaluation of Optimized Inner and Outer Loop Controllers for 4X Flyer under Faulty Actuators

Metaheuristic optimization techniques are a powerful tool to decide the optimal gains for underactuated systems such as quadrotors, considering the multiple controllers involved in the inner and outer loops of the system. This paper deals with the evaluation of performance of the set of controllers (PI and SMC) set by three optimization methods: particle swarm optimization (PSO), grey wolf optimization (GWO), and equilibrium optimization (EO). The disparity of the control gains obtained during the optimization is a sign of the distinction between performance reached by each controller. The proposed study investigates this difference through a robustness test by gradually including faults to the quadrotor actuators. We observed degradation in the agility of quadrotor (stabilization of altitude and attitude) for the faulty case; however, the three controllers showed different tolerances to the fault. The simulation results show that the parameters optimized by EO algorithm, outperform both the PSO and the GWO algorithm, especially for the considered unfavorable cases.