Enhanced Kinematics Calculation for an Online Trajectory Generation Module

This paper presents an extension to a previously published method by the authors, which implemented clothoids within an integrated flight guidance and control system with independent speed control. This method was then used in real flight tests of a highly-automated CS-23 aircraft. The method provided a steady entry and exit manoeuvre to a turn. Now, the aim of this paper is to show an enhancement of the previously published algorithm in the context of the trajectory reference point kinematics calculation for the clothoid manoeuvre. Nonetheless, the proposed methodology remains applicable for a variety of other trajectory curves (e.g. splines). The improved reference point calculation yields a smoother command for the trajectory controller, which uses 2^nd order error dynamics. To illustrate the enhancements by the proposed algorithm, exhibits from a high-fidelity simulation framework of the CS-23 aircraft are depicted. Additionally, results of a flight test with the CS-23 aircraft are shown, discussed, and related to the previously published results. Furthermore, a worst-case approximation, in a Monte-Carlo like approach, of the maximal projection error for the proposed method is presented.