Dynamic response analysis of aircraft with actuation system failure: open-loop and closed-loop cases

Abstract

On flight control implementation, the control surface actuator system plays one of the key roles that will significantly affect the closed-loop performance of the aircraft. The actuators must provide the required effort for moving the control surface so that the desired control action can be reached. Any failure on the actuator system will limit or degrade the operation of the control surface, so that it will affect the performance of the system in controlling the aircraft, or even worse, may bring the aircraft into an unsafe condition. In this project, the effect of some control surface problems due to actuator failures are modeled, simulated, and analyzed. To reconstruct the situation, the control device failure model is integrated into the flight dynamic model of an aircraft. The numerical model of the equation then is used for simulating the aircraft response under some failure conditions. It can be seen from the simulation results that control surface failure can significantly affect the trim condition of the aircraft, since the failures can change the balance of forces and moments that work on the aircraft. The simulation results also show that for some control surface failures may initiate an asymmetrical response from the aircraft dynamics. On closed-loop simulations, where some type of flight control systems for stabilization and maneuvering tasks are implemented, control surface failures may affect the performance of the control system. The results of the study suggest that any possibilities of control surface failure must be anticipated, by using a robust control scheme or other reconfigurable schemes that can cope with the change in the dynamic characteristics due to the failures.