Robust flight sliding modes control system design for nonlinear aircraft with parameter uncertainties

In this paper, an aircraft robust flight control system design is studied via sliding mode techniques with parameter uncertainties in flight speed, altitude, aerodynamic coefficients without any reconfiguration of control parameters. Complete nonlinear six degree of freedom flight dynamics model is built for a conventional aircraft in state space. Control commands are assumed to be aileron deflection of wings, elevator deflections of horizontal stabilizers, rudder deflection of vertical fin, trust input of jet-engine/propeller. Also, actuator dynamics are considered. A design example is given to illustrate effectiveness of proposed control system with and without actuator dynamics for three different flight conditions.