Nair, Priya G. (Indian Institute of Technology, Bombay), Joshi, Prof. Ashok (Aerospace Engineering, Indian Institute of Technology, Mumbai)

A Modified Re-Entry Trajectory Planning Approach and Comparison with EAGLE Method

Scheduled for presentation during the Regular Session "Spacecraft dynamics and control 1" (WeM3), Wednesday, April 3, 2019, 11:30−12:00, BL281.2

5th CEAS Conference on Guidance, Navigation and Control, April 3-5, 2019, Milano, Italy

This information is tentative and subject to change. Compiled on April 19, 2024

Abstract

In this paper, a continuous smooth drag acceleration profile is generated for the hypersonic entry phase of the winged entry vehicles. Evolved Acceleration Guidance Logic for Entry (EAGLE) method is used as the baseline, and a modified strategy is developed in this paper, to plan a reference drag-energy profile. In this work, a continuous smooth drag acceleration profile is created in the drag-energy plane using cubic spline interpolation, whereas in EAGLE method a three segment constant drag-energy profile with sharp corners is used. With this modified strategy, unlike EAGLE method, the actual trajectory follows the reference trajectory without many oscillations both in drag-energy space and altitude-velocity space. This method has been tested on SL-12 vehicle which has a medium L/D ratio. Simulation results show that all the path and terminal constraints are satisfied and the downrange requirement is also met. The terminal altitude and velocity errors are minimal compared to the EAGLE method and are within the permissible range. Robustness analysis is also carried out to show the effectiveness of the proposed method.