On design of attitude controller for rotor aircraft with fuel sloshing disturbance

Fuel sloshing is the unwanted attitude disturbance of rotor aircraft which represents the force of the fuel impact the tank wall. The fuel sloshing model used for rotor aircraft represents each sloshing mode as a mass-spring-damper system. Then a nonlinear dynamic model was achieved by theoretical and empirical method to determine the relationship among the voltage, the speed of the propeller and the lift force. A sliding mode controller was developed and compared with a optimized PID controller in terms of fuel sloshing disturbance. Furthermore, the hardware in the loop simulation system with two degree of freedom was given to demonstrate the validity of the algorithms. The result shows that a little input effort can achieve a better robust performance by adopting the sliding mode controller than the PID controller.