A control system for flight at asymmetrical thrust

A lateral-directional flight control system for asymmetrical thrust is designed and applied to different aircraft models in the MATALAB/SIMULINK environment. The controller uses the full linearized lateral-directional dynamic model and includes a classical inner loop stability augmentation system. The approach consists of demanding zero yaw velocity and a specific bank angle toward the operative engine. By adjusting the gain of a proportional regulator and properly choosing the inner loop gains, the control system generates the aileron and rudder command laws which yield a stabilized straight flight, where the consigned value for the bank angle is obtained, along with zero yaw rate, zero roll rate and the correct sideslip angle. For validation purposes, controller results are compared to values obtained directly through solving the steady state lateral directional equations of motion with one engine inoperative and good agreement is demonstrated. The time required by the autopilot to reach stabilized flight is around five to eight seconds for all cases considered.