Fundamental Study of Momentum-Exchange-Impact-Damper-Based Robust Landing Gear

When a spacecraft lands, a large shock load can lead to undesirable responses such as rebound and tripping. The authors previously discussed the problem of controlling these shock responses using momentum exchange impact dampers. An active/passive hybrid momentum exchange impact damper, which included an active actuator, was proposed. The momentum exchange impact dampers' performances are evaluated by the maximum rebound height, which is proportional to the mechanical energy of the spacecraft. However, the time responses of the energies have not been explained. In addition, the effectiveness of momentum exchange impact dampers was evaluated only in a onedimensional motion simulation. This paper includes theoretical analyses, simulation studies, and experiments. The time responses of the energies of momentum exchange impact dampers are discussed. This paper proposes a robust landing gear system for spacecraft using a hybrid momentum exchange impact damper and evaluates its robustness against ground stiffness variation. First, momentum exchange impact dampers are applied to a mass-damper-spring model, which takes the ground viscosity into account. Next, the proposed model's effectiveness is verified by simulation studies and some experimental results. Finally, this paper studies two-dimensional motion analyses to address rotational motion.

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“…The cases of landing on hard ground (k f 3.6 × 10 5 N∕m) are discussed in [19] in detail. Similar to Fig.…”

Section: Simulation Study For Momentum Exchange Impact Damper Compmentioning

confidence: 99%

Robust Landing Gear System Based on a Hybrid Momentum Exchange Impact Damper

Kushida¹,

Hara²,

Otsuki

et al. 2013

Journal of Guidance, Control, and Dynamics

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“…Additionally, the analysis of landing overload performance has also attracted great attention from the literature. Jones and Hinchey [32] and Kushida [33] have studied the impact of landing environment on airframe overload response, providing guidance for the study of buffering characteristics. In order to study the impact of different influencing factors on the overload response of the Lunar lander, Alderson and Wells [34] created mathematical models and computer programs.…”

Section: Introductionmentioning

confidence: 99%

Improving the Buffer Energy Absorption Characteristics of Movable Lander-Numerical and Experimental Studies

et al. 2020

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To improve the soft-landing crash performance of the movable lander (ML), this study presents an investigation of a newly designed gradual energy-absorbing structure subjected to impact loads using an ML for theoretical calculation and numerical simulations. In this work, we present a novel computational approach to optimizing the energy absorption (EA) of the ML. Our framework takes as inputting the geometrical parameter (GP) as well as EA. The finite element model of the HB1, HB2, and HB3 was established and effectively verified using numerical simulation and experimental data. The relationship between the GP of the buffer material and the EA was obtained through static experiment and impact experiment, and the cushioning performance of the lander was optimized according to the ML load mass, contact speed, and EA function. According to the optimization results, we chose an outer diameter of 240 mm, an inner diameter of 50 mm, heights of HB1 = 140 mm, HB2 = 110 mm, and HB3 = 225 as the collocation, and completed the numerical simulation of three different cases. By comparing the results of theoretical calculation and numerical simulation experiments, it can be found that the overload response rates of the main body in 4 type landing, 2-2 type landing, and 1-2-1 type landing are 4.72 G, 2.61 G, and 2.33 G, respectively. It also laid the foundation for the theoretical and methodological research of the ML and manned lander in the future.

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“…To overcome the drawbacks of the aforementioned technologies, some newer landing technologies have been developed [20][21][22][23][24][25][26][27][28][29]. A technology that relies on a momentum exchange impact damper (MEID) was developed, based on the momentum exchange principle [20][21][22][23][24][25][26][27][28].…”

mentioning

confidence: 99%

“…A technology that relies on a momentum exchange impact damper (MEID) was developed, based on the momentum exchange principle [20][21][22][23][24][25][26][27][28]. Figure 1 shows the generalized-hybrid MEID (G-HMEID), which incorporates upper and lower damper masses and an active/ passive hybrid launching mechanism [27].…”

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Analytical and Experimental Investigation of Base–Extension Separation Mechanism for Spacecraft Landing

Saeki

Hara

Otsuki

et al. 2015

Journal of Spacecraft and Rockets

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Future planetary exploration requires spacecraft to land softly on rough terrain and in severe environments. Since conventional landing methods have problems such as high rebounds and excessive resource consumption, the baseextension separation mechanism, which combines springs and separable units, is proposed as a novel landing mechanism. Although the mechanism performed good soft landings, the performance evaluation was limited. Therefore, this study evaluated its performance multilaterally. The proposed technology was analytically compared with two other landing technologies: a generalized-hybrid momentum exchange impact damper and an aluminum foam landing gear. The proposed technology suppressed rebound and acceleration better than the generalized momentum exchange impact damper. Once the components of the proposed technology had been lightened, its energy conversion efficiency matched that of the aluminum foam landing gear. In addition, experiments were conducted using small-scale models to confirm the feasibility. The experiments showed that the proposed technology has good soft landing performance, matching the results of the simulations. Finally, design optimization was discussed for further performance improvements. It was clarified that both the spring stroke and the pre-tension length of the spring should be large. Optimizing the design of the spring improved its performance and compensated for its disadvantages.Nomenclature a = initial compression of L-spring in generalized-hybrid momentum exchange impact damper model, m c f = viscous damping coefficient between masses and surface of the ground, N · s∕m c f;2 = viscous damping coefficient between base and surface of the ground, N · s∕m c f;3 = viscous damping coefficient between upper gear and surface of the ground, N · s∕m c l = viscous damping coefficient between base and linear guide in base-extension separation mechanism model, N · s∕m d = stretched length of spring at t equal to T 2 , m E g = energy absorbed by ground damping, J E loss = energy increment of base caused by separation delay, J E 0 = initial energy of base-extension separation mechanism system, J F = maximum force of actuator in generalized-hybrid momentum exchange impact damper model, N f 1 = initial tension of spring in practical base-extension separation mechanism model (upper part of the spring), N f 2 = initial tension of spring in practical base-extension separation mechanism model (lower part of the spring), N Gs = transfer function of second-order low-pass Butterworth filter g = gravitational acceleration, m∕s 2 h r = maximum rebound height of base, m h 0 = initial fall height of base, m k f = stiffness between masses and surface of the ground, N∕m k f;2 = stiffness between base and surface of the ground, N∕m k f;3 = stiffness between gear and surface of the ground, N∕m k g = stiffness between gear and surface of the ground in practical base-extension separation mechanism model, N∕m k l = stiffness of L-spring in generalized-hybrid momentum exchange impact damper model, N∕m ...

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Fundamental Study of Momentum-Exchange-Impact-Damper-Based Robust Landing Gear

Cited by 6 publications

References 7 publications

Robust Landing Gear System Based on a Hybrid Momentum Exchange Impact Damper

Robust Landing Gear System Based on a Hybrid Momentum Exchange Impact Damper

Improving the Buffer Energy Absorption Characteristics of Movable Lander-Numerical and Experimental Studies

Analytical and Experimental Investigation of Base–Extension Separation Mechanism for Spacecraft Landing

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