A Fast Algorithm for Onboard Atmospheric Powered Descent Guidance

• Published in: IEEE transactions on aerospace and electronic systems Vol. 59; no. 5; pp. 1 - 14
• Main Authors: Chen, Yushu, Yang, Guangwen, Wang, Lu, Chen, Haipeng, Gan, Qingzhong, Xu, Quanyong
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aerodynamic forces; Aerodynamics; aircraft landing guidance; Algorithms; Computing costs; Descent; fast solvers; Iterative methods; Linear systems; Microprocessors; Monte Carlo simulation; Onboard; optimization methods; Radiation hardening; Real time; Run time (computers); Solvers
• ISSN: 0018-9251; 1557-9603
• DOI: 10.1109/TAES.2023.3271961

Atmospheric powered descent guidance (APDG) can be solved by successive convexification; however, its onboard application is impeded by high computational cost. When aerodynamic forces are ignored, powered descent guidance (PDG) can be converted to a single convex problem. In contrast, APDG has to be converted into a sequence of convex subproblems, each of which is significantly more complicated. Consequently, the computation increases sharply. A fast real-time interior point method was presented to solve the correlated convex subproblems efficiently onboard in the work. The main contributions are as follows: Firstly, an algorithm was proposed to accelerate the solution of linear systems that cost most of the computation in each iterative step by exploiting the specific problem structure. Secondly, a warm-starting scheme was introduced to refine the initial value of a subproblem with a rough approximate solution of the former subproblem, which lessened the iterative steps required for each subproblem. The method proposed reduced the run time by a factor of 9 compared with the fastest publicly available solver tested in Monte Carlo simulations to evaluate the efficiency of solvers. Runtimes on the order of 0.6 s are achieved on a radiation-hardened flight processor, which demonstrated the potential of the real-time onboard application.