Soft landing stability analysis of a Mars lander under uncertain terrain

Yang, Dong; Jian, Ding; Wang, Chunjie; Wang, Hui; Liu, Xueao

doi:10.1016/j.cja.2021.10.034

Cited by 13 publications

(8 citation statements)

References 29 publications

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“…The flexible rod is replaced with two rigid links connected with the main body and primary strut with a universal joint, respectively, and a prismatic joint simulating the axial deformation. The translation t and rotation β measured by vectors r AB and boldrAB1 are used to simulate the nonlinear deformation, and nonlinear couple M acting on the universal joint are used to simulate the forces arising from deformation (Dong et al , 2021). The correlation between β and t and the change of M with β are obtained by finite element analysis, as shown in Figure 4.…”

Section: Dynamics Modeling For the Mars Landermentioning

confidence: 99%

“…Song and Wang (2013) proposed a Monte-Carlo-based method to estimate the possibilities of landing stability indices. Dong et al (2021) analyzed the landing performance of a Mars lander using a numerical landing terrain model. Previously, we analyzed the effects of various landing conditions on the reliability of a lunar lander with Monte Carlo simulation and Bayesian estimation.…”

Section: Introductionmentioning

confidence: 99%

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Stability analysis of Mars soft landing under uncertain landing conditions and two landing strategies

Jian

Liu

Yang

et al. 2022

AEAT

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Purpose The purpose of this paper is to study the landing performance of the Mars lander considering uncertain landing conditions under two landing modes. Design/methodology/approach A dynamics analysis model for the legged Mars lander is established for landing simulation, where the nonlinear large-deformation flexible buffer rods are equivalently modeled with a rigid-body mechanism with external forces and movement limit. Sensitivities of the landing stability to various landing conditions are analyzed using the Quasi–Monte-Carlo-based Sobol’ method and computer-aided landing simulations. Moreover, based on the results of sensitivity analysis, sensitive parameters are selected for estimating the safe boundaries for stability indices of rotation and clearance. Findings It can be concluded from this study that the lander has excellent ability against overturning. The shutdown-before-touchdown strategy helps to maintain than landing pose, and the shutdown-at-touchdown strategy helps to prevent the nozzle from colliding with the surface of Mars. Practical implications This study provides a theoretical reference to choose the better landing strategies for Mars landers considering uncertain landing conditions. Originality/value A parameterized dynamics Mars lander model and a simplification method are proposed to simulate the landing on Mars. Uncertain landing conditions are parameterized and considered in the dynamics model. Sensitivity analysis and safe boundary methods are used to compare the landing performances with two landing strategies.

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Section: Dynamics Modeling For the Mars Landermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stability analysis of Mars soft landing under uncertain landing conditions and two landing strategies

Jian

Liu

Yang

et al. 2022

AEAT

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“…In planetary exploration, landing stability or landing site selection are commonly conducted based on MCS. Dong et al [8] established a dynamic model for a Mars lander with attitude control thrusters. Their probability analysis emphasized the influence of irregular terrain.…”

Section: Introductionmentioning

confidence: 99%

Landing Reliability Assessment of Airdrop System Based on Vine-Bayesian Network

Cheng

Yang

2023

International Journal of Aerospace Engineering

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The landing phase of an airdrop process is prone to accidents, and thus, it is important to assess the landing reliability for an airdrop system. However, full field tests to assess the reliability are unacceptable due to their cost and the time required. As such, it is necessary to estimate the reliability in the design stage. To address this problem, a method based on vine-Bayesian Network (vine-BN) is proposed to assess the landing reliability by fusing multisource information. First, the network structure is determined by the relationship between data of simulation or ground tests and failure modes. Then, nodes are defined as random variables on [0, 1] based on the definition of the performance metric. Finally, the dependence between nodes is quantified by expert opinions. To illustrate the effectiveness of the method, a particular ground test or simulation is chosen to establish a network for a typical heavy cargo airdrop system (HCADS). Forward and backward propagation is carried out on the network. The forward analysis predicts the landing reliability in the design stage through multisource information fusion. Beta distribution is applied to fit the fusion result, so Bayesian inference is made to perform field test times decision-making. The backward analysis works to identify the key performance metrics related to landing reliability. The results and analysis manifest that vine-BN is feasible for fusing multisource information. Through the network, the reliability of the current design can be predicted effectively, and the field test times can be remarkably reduced. This method plays a crucial role in airdrop system design and reducing test time and labor.

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“…Yin [17] developed a planar dynamic model of a three-legged lander considering the asymmetric characteristic and the leg-leg coupling to understand the landing process of the asteroid probe with the three-legged cushioning mechanism. Yang [18] established a 3D dynamics model of China's Mars lander considering plastic deformation parts and nonlinear contact forces. The equation of the model is too complex to be widely used in other landers.…”

Section: Introductionmentioning

confidence: 99%

“…The dynamic response of the lunar soil during landings, such as the penetration depth of the footpad and the soil's vertical and horizontal loadbearing capacity, are critical parameters in determining the stable position and angle of the lander after landing. There are three kinds of contact force models that have been derived: (1) the added mass model [19]; (2) the load model based on the Bekker theory [20], which defines contact force F as a function of the indentation depth δ: F = K × δ n , where K represents the stiffness parameter, and the exponent n depends on the topological properties of the contacting surfaces; (3) the simplified dynamic bearing model in the form of the function on the force versus depth and velocity [18]. Moreover, many studies of fixed-shape (non-locomoting) objects impacting and penetrating dry granular media have revealed reaction forces that can be described by F = F p (z) + αv 2 (1)…”

Section: Introductionmentioning

confidence: 99%

3D Soft-Landing Dynamic Theoretical Model of Legged Lander: Modeling and Analysis

Wang,

Chen,

Chen

et al. 2023

Aerospace

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In this paper, a novel 3D (three-dimensional) soft-landing dynamic theoretical model of a legged lander is developed in detail as well as its numerical solution process. The six degrees of freedom motion (6-DOF) of the base model of the lander with mass center offset setting is considered in the model as well as the spatial motion (3-DOF) of each landing gear. The characteristics of the buffering force, the footpad–ground contact, and the inter-structure friction are also taken into account during the motion of each landing gear. The direct constraint violation correction is used to control the constraint stabilization of the nonlinear dynamic equation. Comparative studies between the results from the proposed model and the simulated model (built in MSC Adams) under four classical load cases show the validity of the model. Additionally, the influences of different types of contact force models, friction force models, and a friction correction model used in the soft-landing dynamic model are further investigated as a step toward understanding the soft-landing dynamic performance and the feasibility of the dynamic model method of a legged lander. The results indicate that a precise lateral force model of the footpad–ground contact is necessary to obtain the soft-landing performance of one lander during soft landing.

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Soft landing stability analysis of a Mars lander under uncertain terrain

Cited by 13 publications

References 29 publications

Stability analysis of Mars soft landing under uncertain landing conditions and two landing strategies

Stability analysis of Mars soft landing under uncertain landing conditions and two landing strategies

Landing Reliability Assessment of Airdrop System Based on Vine-Bayesian Network

3D Soft-Landing Dynamic Theoretical Model of Legged Lander: Modeling and Analysis

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