Tailless aircraft flight control using multiple time scale reconfigurable sliding modes

A triple time scale tailless aircraft flight control problem is addressed via continuous sliding mode control. A reconfigurable sliding mode flight controller is designed that achieves robust, high accuracy command angle tracking both before and after damage to an aircraft. Command angles and angular rate commands are robustly tracked in outer and inner loops correspondingly via finite reaching time continuous sliding mode controllers. An optimal control allocation algorithm is employed using nominal mathematical model of an aircraft. Sliding surface boundary layer reconfiguration (direct adaptation) is used in the very inner loop to account for actuator dynamics, deflection limits, and rate limits. On-line damage identification is not required by this design. The reconfigurable sliding mode flight control technique is applied to a flight dynamics model of a tailless jet fighter that was developed under is the innovative control effectors program. Simulations demonstrate stability and high accuracy tracking performance without violation of actuator limits.