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Journal ArticleDOI

Constrained optimal multi-phase lunar landing trajectory with minimum fuel consumption

TL;DR: The proposed optimal trajectory technique satisfies the mission constraints in each phase and provides an overall fuel-minimizing guidance command history.
About: This article is published in Advances in Space Research.The article was published on 2017-12-01. It has received 12 citations till now. The article focuses on the topics: Lunar lander.
Citations
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Journal ArticleDOI
01 Mar 2020
TL;DR: An autonomous optimal guidance algorithm for multi-phase lunar soft landing is presented and an initial continuity of the guidance command is attempted in an approximate manner to facilitate a smooth transition between successive segments.
Abstract: In this paper, an autonomous optimal guidance algorithm for multi-phase lunar soft landing is presented. Various stringent requirements of a typical multi-phase soft landing are incorporated in guidance formulation. The proposed guidance law is formulated using the model predictive static programming (MPSP), which is an emerging computational guidance algorithm. High accuracy on the terminal position and velocity at the end of each phase is ensured, as the formulation of the MPSP inherently poses terminal output as a set of hard constraints. The spacecraft terminal orientation requirement is embedded in the guidance formulation in a soft constrained manner. Moreover, to facilitate a smooth transition between successive segments, an initial continuity of the guidance command is also attempted in an approximate manner. The effectiveness of the proposed method is demonstrated with simulation results. A processor-in-loop simulation study has been presented to demonstrate the feasibility of the proposed guidance law for possible on-board implementation.

12 citations

Journal ArticleDOI
19 Jun 2019
TL;DR: A waypoint constrained multi-phase nonlinear optimal guidance scheme is presented for the soft landing of a spacecraft on the Lunar surface by using the recently developed computation algorithms.
Abstract: A waypoint constrained multi-phase nonlinear optimal guidance scheme is presented in this paper for the soft landing of a spacecraft on the Lunar surface by using the recently developed computation...

12 citations

Journal ArticleDOI
19 Jul 2021
TL;DR: The last phases of autonomous lunar landing trajectories are addressed and the proposed guidance is based on the Particle Swarm Optimization, and the differential flatness approach, which is a subclass of the inverse dynamics technique.
Abstract: The problem of real-time optimal guidance is extremely important for successful autonomous missions. In this paper, the last phases of autonomous lunar landing trajectories are addressed. The proposed guidance is based on the Particle Swarm Optimization, and the differential flatness approach, which is a subclass of the inverse dynamics technique. The trajectory is approximated by polynomials and the control policy is obtained in an analytical closed form solution, where boundary and dynamical constraints are a priori satisfied. Although this procedure leads to sub-optimal solutions, it results in beng fast and thus potentially suitable to be used for real-time purposes. Moreover, the presence of craters on the lunar terrain is considered; therefore, hazard detection and avoidance are also carried out. The proposed guidance is tested by Monte Carlo simulations to evaluate its performances and a robust procedure, made up of safe additional maneuvers, is introduced to counteract optimization failures and achieve soft landing. Finally, the whole procedure is tested through an experimental facility, consisting of a robotic manipulator, equipped with a camera, and a simulated lunar terrain. The results show the efficiency and reliability of the proposed guidance and its possible use for real-time sub-optimal trajectory generation within laboratory applications.

7 citations

Journal ArticleDOI
TL;DR: The Chandrayaan-2 spacecraft has been successfully rendezvoused with the Moon on 2 0 th August, 2019 UT and has attempted a soft-landing on 6 th September 2019 UT.

7 citations

Journal ArticleDOI
TL;DR: Simulation results demonstrate that the established navigation error-based trajectory optimization model can reflect the real situation of multi-phase task and is able to calculate the collision probability between the vehicle and the obstacle when GPS is unavailable underwater, thus ensuring the safety of underwater navigation.

6 citations

References
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Journal ArticleDOI
23 Oct 2009-Science
TL;DR: Analysis of recent infrared mapping by Chandrayaan-1 and Deep Impact, and reexamining Cassini data obtained during its early flyby of the Moon, Pieters et al. reveal a noticeable absorption signal for H2O and OH across much of the surface, implying that solar wind is depositing and/or somehow forming water and OH in minerals near the lunar surface, and that this trapped water is dynamic.
Abstract: The search for water on the surface of the anhydrous Moon had remained an unfulfilled quest for 40 years. However, the Moon Mineralogy Mapper (M 3 ) on Chandrayaan-1 has recently detected absorption features near 2.8 to 3.0 micrometers on the surface of the Moon. For silicate bodies, such features are typically attributed to hydroxyl- and/or water-bearing materials. On the Moon, the feature is seen as a widely distributed absorption that appears strongest at cooler high latitudes and at several fresh feldspathic craters. The general lack of correlation of this feature in sunlit M 3 data with neutron spectrometer hydrogen abundance data suggests that the formation and retention of hydroxyl and water are ongoing surficial processes. Hydroxyl/water production processes may feed polar cold traps and make the lunar regolith a candidate source of volatiles for human exploration.

620 citations

Journal ArticleDOI
TL;DR: Key theoretical results in pseudospectral optimal control that have proven to be critical for a successful flight are reviewed along with emerging trends and techniques in both theory and practice.

311 citations

Book
01 Jan 1980
TL;DR: In this article, a review of the structures of planetary atmospheres and aerodynamic forces, equations are derived for flight over a spherical planet, and the performance of long-range hypervelocity vehicles in extra-atmospheric flight is analyzed.
Abstract: The book treats hypersonic flight trajectories and atmospheric entry flight mechanics in light of their importance for space shuttle entry Following a review of the structures of planetary atmospheres and aerodynamic forces, equations are derived for flight over a spherical planet, and the performance of long-range hypervelocity vehicles in extra-atmospheric flight is analyzed Consideration is then given to vehicle trajectories in the powered and atmospheric reentry phases of flight, and several first-order solutions are derived for various planetary entry situations The second-order theory of Loh for entry trajectories is presented along with the classical theories of Yaroshevskii and Chapman for entry into planetary atmospheres, and the thermal problems encountered in hypersonic flight are analyzed A unified theory for entry into planetary atmospheres is then introduced which allows the performance of a general type of lifting vehicle to be studied, and applied to the analysis of orbit contraction due to atmospheric drag, flight with lift modulation and lateral maneuvers

293 citations

Journal ArticleDOI
TL;DR: A class of computational methods based on pseudospectral approximations of the differential constraints that are assumed to be given in the form of controlled differential inclusions including the usual vector field and differential-algebraic forms is presented in this article.
Abstract: A class of computational methods for solving a wide variety of optimal control problems is presented; these problems include nonsmooth, nonlinear, switched optimal control problems, as well as standard multiphase problems. Methods are based on pseudospectral approximations of the differential constraints that are assumed to be given in the form of controlled differential inclusions including the usual vector field and differential-algebraic forms. Discontinuities and switches in states, controls, cost functional, dynamic constraints, and various other mappings associated with the generalized Bolza problem are allowed by the concept of pseudospectral (PS) knots. Information across switches and corners is passed in the form of discrete event conditions localized at the PS knots. The optimal control problem is approximated to a structured sparse mathematical programming problem. The discretized problem is solved using off-the-shelf solvers that include sequential quadratic programming and interior point methods. Two examples that demonstrate the concept of hard and soft knots are presented.

276 citations

Book ChapterDOI
01 Jan 1999

189 citations