Gain scheduled automatic flight control systems design for a light commercial helicopter model

In this paper, nonlinear rigid body dynamics for rotorcraft mathematical model is studied. A linearization of helicopter flight dynamics is evaluated. Automatic Flight Control System (AFCS) with gain scheduled LQ optimal control is designed based on look-up tables. Stability analyses are performed and results are illustrated graphically for open and closed-loop systems. As seen from results, LQ optimal control system pushes eigenvalues to left side of imaginary axis without excessive control inputs to maintain stability of naturally unstable rotorcraft dynamics. Proposed AFCS is tested by nonlinear flight dynamics model in Matlab-Simulink environment. Simulation results illustrate effectiveness of evaluated method and techniques.