Aircraft Flight Control in Wind Shear Using Sequential Dynamic Inversion

Longitudinal wind shear flight control laws are developed for the dynamics of a twin-jet transport aircraft using nonlinear dynamic inversion. Time-scale decomposition simplifies controller design by partitioning it into slow and fast time scales. The effects of time-varying winds are explicitly considered in the derivation of the controllers. Three inverting controllers are developed and evaluated: airspeed/climb rate, groundspeed/climb rate, and throttle/climb rate. The implementation of a climb rate scheduling strategy makes it possible for the resultant flight paths to mimic the essential features of optimal escape trajectories developed in an earlier study, where altitude is exchanged for airspeed as a function of microburst strength. Nomenclature D Drag, lbf Es Specific Energy, ft F Nondimensional wind shear hazard index g Acceleration due to gravity, ft/sec2 h Altitude, ft Iyy Moment of Inertia about body y-axis, slug-ft2 L Lift, lbf m mass, slugs * Senior Scientist, Charles River Analytics Inc., Cambridge, MA. Member, AIAA. ** Professor. Associate Fellow, AIAA. Appeared in the Journal of Guidance, Control, and Dynamics, September-October 1995.