Optimized Guidance Methods for Smooth Transitions in UAS Path Following

Abstract

Many traditional guidance algorithms for Unmanned Aerial Systems will command maneuvers that may be over-aggressive in sharp turns or large errors, especially in the longitudinal frame which can result in stall. To prevent this, more gradually increasing or steady ascent/descent/turn rates should be commanded. In longitudinal, a guidance law is developed using aircraft dynamics that both keeps trim conditions salient while also tightly constraining ascent/descent rates, which can then be optimized through the linear quadratic regulator technique. Furthermore, this base guidance is decoupled from initial conditions. In lateral, a curvature path planning navigation is introduced to eliminate step input controls in turns. Results show that the aircraft can track the path as well as traditional algorithms, while also producing more reasonable reactions to lateral and longitudinal errors.