3/29/2024 Debra Levey Larson
Written by Debra Levey Larson
Daniel Engel, a second-year Ph.D. aerospace engineering student won the Atmospheric Flight Mechanics Student Paper Competition at the American Institute of Aeronautics and Astronautics SciTech 2024 Forum.
The title of Engel’s paper is, “Assessment of Control Algorithms for Mars Entry Vehicles with Flap-Based Trajectory Control.”
Engel’s co-advisers are Robyn Woollands, professor in the Department of Aerospace Engineering at the University of Illinois Urbana-Champaign, and Zachary Putnam, adjunct assistant professor Zachary Putnam, now at the Johns Hopkins Applied Physics Lab. Putnam and Soumyo Dutta, who is Engel’s research collaborator from the NASA Langley Research Center, are co-authors on the paper.
His overall research is on assessing the entry performance of flap-based steering systems and comparing performance to state-of-the-art bank-angle steering systems. In the paper, the team looked at comparisons of different control algorithms and flap configurations for tracking angle of attack and sideslip angle commands on a vehicle with flaps during a Mars entry.
The control algorithms under consideration were a model predictive controller and a linear quadratic regulator. Different flap sizes and placements around the vehicle were also considered.
“The results showed both of the control algorithms may be viable for use on an entry vehicle with flaps, but the model predictive controller provided improved command tracking at an increased computational cost,” Engel said.
According to Engel, the model predictive control algorithm was also able to provide similar tracking for the different flap configurations, provided a set of flaps had sufficient control authority to trim to the desired commands.
“This study also showed that rolling moments from the sides of the flaps and an off-axis center-of-gravity can lead the entry vehicle to roll significantly during entry, unless mitigated with an additional control effector,” Engel said. He added that the rolling behavior was the subject of questions and discussion following his presentation at AIAA’s SciTech.
Engel did some of the development work on this research on a summer internship in 2022 at the NASA Langley Research Center.
The research was supported by a NASA Space Technology Graduate Research Opportunity.