Onboard guidance algorithm for the powered landing phase of a reusable rocket
SONG Yu1, ZHANG Wei1, MIAO Xinyuan1, ZHANG Zhiguo2, GONG Shengping1
1. School of Aerospace Engineering, Tsinghua University, Beijing 100084, China; 2. Beijing Institute of Aerospace System Engineering, Beijing 100076, China
Abstract：Precise soft rocket recovery landings require precise guidance, navigation, and control. A convex optimization guidance algorithm was developed for soft vertical rocket recovery landings and tested in a closed-loop simulation system. A lossless convex model was combined with successive convex iterations to transform the rocket recovery stage guidance problem into a convex optimization problem using the interior point method. The algorithm robustness was evaluated for various factors including random atmospheric disturbances, engine throttling characteristics, random navigation system deviations, and system delays. The simulations show that the onboard guidance algorithm has millisecond convergence and is very robust. Various simulations show that the closed-loop simulation results can provide precise soft landings for rocket recovery even with the combined effects of various disturbances including dynamic environments, control and navigation system deviations, and system delays.
[1] BAYLOR M. With Block 5, SpaceX to increase launch cadence and lower prices[EB/OL].[2018-07-05]. https://spaceflight.com. [2] 李爽, 陶婷, 江秀强, 等. 月球软着陆动力下降制导控制技术综述与展望[J]. 深空探测学报, 2015, 2(2):111-119. LI S, TAO T, JIANG X Q, et al. Review and prospect of the powered descent guidance and control technologies for lunar soft landing[J]. Journal of Deep Space Exploration, 2015, 2(2):111-119. (in Chinese) [3] 王劼, 崔乃刚, 刘暾. 通过"建立月球垂线"实现月球软着陆方法研究[J]. 导弹与航天运载技术, 2000(4):45-47. WANG J, CUI N G, LIU D. Study on lunar soft landing by the method of establishment of the lunar perpendicular[J]. Missiles and Space Vehicles, 2000(4):45-47. (in Chinese) [4] 和兴锁, 林胜勇, 张亚峰. 月球探测器直接软着陆最优轨道设计[J]. 宇航学报, 2007, 28(2):409-413. HE X S, LIN S Y, ZHANG Y F. Optimal design of direct soft-landing trajectory of lunar prospector[J]. Journal of Astronautics, 2007, 28(2):409-413. (in Chinese) [5] PARSLEY J. Near-optimal feedback guidance for an accurate lunar landing[D]. Tuscaloosa:University of Alabama, 2012. [6] KERR R A. Mars exploration hang on! Curiosity is plunging onto Mars[J]. Science Magazine, 2012, 336(6088):1498-1499. [7] 于正湜, 崔平远. 行星着陆自主导航与制导控制研究现状与趋势[J]. 深空探测学报, 2016, 3(4):345-355. YU Z S, CUI P Y. Research status and developing trend of the autonomous navigation, guidance, and control for planetary landing[J]. Journal of Deep Space Exploration, 2016, 3(4):345-355. (in Chinese) [8] 崔平远, 朱圣英, 崔祜涛. 小天体软着陆自主光学导航与制导方法研究[J]. 宇航学报, 2009, 30(6):2159-2164, 2198. CUI P Y, ZHU S Y, CUI H T. Autonomous optical navigation and guide method for soft landing on small bodies[J]. Journal of Astronautics, 2009, 30(6):2159-2164, 2198. (in Chinese) [9] 秦同, 朱圣英, 崔平远, 等. 行星着陆动力下降段相对视觉导航方法[J]. 宇航学报, 2019, 40(2):164-173. QIN T, ZHU S Y, CUI P Y, et al. Relative optical navigation in powered descent phase of planetary landings[J]. Journal of Astronautics, 2019, 40(2):164-173. (in Chinese) [10] SCHARF D P, REGEHR M W, VAUGHAN G M, et al. ADAPT demonstrations of onboard large-divert guidance with a VTVL rocket[C]//2014 IEEE Aerospace Conference. Big Sky, USA:IEEE, 2014:1-18. [11] NASA Mars 2020 Mission[Z/OL].[2019-08-21]. https://mars.nasa.gov/mars2020. [12] 张志国, 马英, 耿光有, 等. 火箭垂直回收着陆段在线制导凸优化方法[J]. 弹道学报, 2017, 29(1):9-16. ZHANG Z G, MA Y, GENG G Y, et al. Convex optimization method used in the landing-phase on-line guidance of rocket vertical recovery[J]. Journal of Ballistics, 2017, 29(1):9-16. (in Chinese) [13] ACIKMESE B, PLOEN S R. Convex programming approach to powered descent guidance for Mars landing[J]. Journal of Guidance, Control, and Dynamics, 2007, 30(5):1353-1366. [14] BLACKMORE L, ACIKMESE B, SCHARF D P. Minimum-landing-error powered descent guidance for Mars landing using convex optimization[J]. Journal of Guidance, Control, and Dynamics, 2010, 33(4):1161-1171. [15] ACIKMESE B, CARSON J M, BLACKMORE L. Lossless convexification of nonconvex control bound and pointing constraints of the soft landing optimal control problem[J]. IEEE Transactions on Control Systems Technology, 2013, 21(6):2104-2113. [16] BLACKMORE L, ACIKMESE B, CARSON J M. Lossless convexification of control constraints for a class of nonlinear optimal control problems[J]. Systems & Control Letters, 2012, 61(8):863-870. [17] LIU X F, LU P, PAN B F. Survey of convex optimization for aerospace applications[J]. Astrodynamics, 2017, 1(1):23-40. [18] LIU X F. Fuel-optimal rocket landing with aerodynamic controls[C]//Proceedings of AIAA Guidance, Navigation, and Control Conference. Grapevine, USA:AIAA, 2017:1-15. [19] SZMUK M, AÇIKMEŞE B. Successive convexification for 6-DoF Mars rocket powered landing with free-final-time[C]//Proceedings of 2018 AIAA Guidance, Navigation, and Control Conference. Kissimmee, USA:AIAA, 2018:617-631. [20] SIMPLICIO P, MARCOS A, BENNANI S. A reusable launcher benchmark with advanced recovery guidance[C]//Proceedings of the 5th CEAS Conference on Guidance, Navigation & Control. Milan, Italy, 2019. [21] MAO Y Q, SZMUK M, ACIKMESE B. A tutorial on real-time convex optimization based guidance and control for aerospace applications[C]//Proceedings of 2018 Annual American Control Conference. Milwaukee, USA:IEEE, 2018:2410-2416. [22] YANG H W, BAI X L, BAOYIN H X. Rapid generation of time-optimal trajectories for asteroid landing via convex optimization[J]. Journal of Guidance, Control, and Dynamics, 2017, 40(3):628-641. [23] SZMUK M, ACIKMESE B, BERNING A W. Successive convexification for fuel-optimal powered landing with aerodynamic drag and non-convex constraints[C]//Proceedings of AIAA Guidance, Navigation, and Control Conference. San Diego, USA:AIAA, 2016. [24] GRANT M, BOYD S. CVX:MATLAB software for disciplined convex programming, Version 2.2[EB/OL].[2019-08-21]. http://cvxr.com/cvx [25] SCHARF D P, ACIKMESE B, DUERI D, et al. Implementation and experimental demonstration of onboard powered-descent guidance[J]. Journal of Guidance, Control, and Dynamics, 2017, 40(2):213-229. [26] DOMAHIDI A, CHU E, BOYD S. ECOS:An SOCP solver for embedded systems[C]//Proceedings of the European Control Conference. Zurich, Switzerland:IEEE, 2013:3071-3076.
2021, Vol. 61 
