INVERTIBILITY AND TRAJECTORY CONTROL FOR NONLINEAR MANEUVERS OF AIRCRAFT

This paper presents an application of the inversion theory to the design of nonlinear control systems for simultaneous lateral and longitudinal maneuvers of aircraft; First, a control law for the inner loop is derived for the independent control of the angular velocity components of the aircraft along roll, pitch, and yaw axes using aileron, elevator, and rudder. Then by a judicious choice of angular velocity command signals, independent trajectory control of the sets of output variables (angle of attack, roll, and sideslip angles), (roll rate, angle of attack, and yaw angle), or (pitch, roll, and yaw angles) is accomplished. These angular velocity command signals are generated in the outer loops using state feedback and the reference angle of attack, pitch, yaw, and roll angle trajectories. Simulation results are presented to show that in the closed-loop system, various lateral and longitudinal maneuvers can be performed in spite of the presence of uncertainty in the stability derivatives.