Comparison of classical and modern landing control system for a small unmanned aerial vehicle

Research presented in the following paper contrasted the modern optimal robust control method with classical one, applied for a landing control system of a small unmanned aerial vehicle. Philosophically speaking, the optimal control used H₂ method meets excellent dynamic performance, while the robustness given by the H_∞ method diminish the effect of disturbance to the performance output. Accordingly, implemented mixed H₂/H_∞ optimal robust control method in this paper appear to meet a balancing result between performance and robustness stability. Three phases of flight, level flight, descent and flare used both classical and modern control system to stabilize and track the desired trajectory, which is exposed heavily to the presence of wind disturbance and ground effect. PID with fuzzy logic approach is employed to switch autopilot between the flight phases. Linear matrix inequality (LMI) approach is clearly suited to find the balanced H₂/H_∞ gain. To sum up, all results simulated in linearized model (Simulink-Flight Gear), strengthened with non-linear model flight simulation (X-Plane). The optimal robust landing control system delivers the performance and stability superior than classical controller one as expected.