Clothoid-Augmented Online Trajectory Generation for Radius to Fix Turns

A trajectory generation approach for the radius to fix leg type is presented, which uses clothoids to ensure smooth transitions between straight and circular sections of the flight path. The derived algorithm is implemented in an integrated modular mission management system for manned and unmanned aerial systems. The trajectory generation module generates inputs for a nonlinear dynamic inversion based 3D trajectory controller using second order error dynamics. By using clothoid segments at the turn-in and turnout transitions, continuous curvature paths can be computed. The capability of the proposed method is demonstrated in flight with a CS-23 experimental aircraft.