Soft Landing System Research Articles

Multi-Objective Optimization Design of an Origami-Inspired Combined Cushion Airbag

To improve the cushioning performance of soft-landing systems, a novel origami-inspired combined cushion airbag is proposed. The geometry size, initial pressure, and exhaust vent area of the cushion airbags are designed preliminarily using a theoretical model. The finite element models, including the returnable spacecraft and cushion airbags, are established via the control volume method (CVM) to analyze the impact dynamic behavior and cushioning performance during the landing attenuation process. The cushioning performance of the cushion airbags in complex landing environments are studied to investigate the influence of horizontal velocity, lateral velocity and nonhorizontal landing surfaces. Four design parameters of the cushion airbags, including the initial pressure, venting threshold pressure, exhaust vent area and polygon edge number, are employed to study their influence on the cushioning performance. A multi-objective optimization model of the cushion airbags based on the neural network and multi-objective water cycle algorithm is established to realize the rapid optimization design. The Pareto front of the maximum overload and specific energy absorption is obtained. The analysis results show that the maximum overload of the proposed combined cushion airbags is 7.30 g. The system with the anti-rollover design can avoid rollover and achieve outstanding cushioning performance in complex landing environments. The maximum overload of the returning spacecraft is decreased by 16.4% from 7.30 g to 6.10 g after multi-objective optimizations. This study could provide the technical support for the soft-landing system design of returnable spacecrafts.

Energy absorption behaviors of a novel buffer lander-leg with Yoshimura core

In the current soft-landing system, the lander-leg and the buffer are two independent parts which may cause weight problem. The traditional mechanical buffers also have their own shortcomings such as small buffer stroke and being non-reusable. A Novel Buffer Lander-leg with Yoshimura core (NBLY) is proposed in this paper, inspired by the Buckling Restrained Brace (BRB). The design details of NBLY and parameter definitions of the core are presented. The finite element analysis modes have been employed to analyze the nonlinear mechanical behaviors of NBLY subjected to the cyclic loading. NBLY with four different core styles of hexagon, octagon, dodecagon and hexadecagon are analyzed and compared. The restraining ratio and cumulative dissipation energy ratio have been obtained to evaluate the energy absorption properties. The results show that the origami pattern has significant influences on the deformation ductility, plastic energy absorbing and axial load transferring to the core. The NBLY with octagon core has outstanding properties, especially the hysteretic energy dissipation and enhancement of compression capacity. The interaction mechanism between the core and encasing member constrains the deformation extensions and contributes to the frictional energy dissipation of the NBLYs. This paper provides a new conceptual design of buffer lander-leg for soft-landing missions. It can realize the reuse function as a buffer lander-leg with better loading-bearing and energy absorption behaviors.

The Problem of Elements Returning of Launch Vehicles and the Ways of Its Solution

The work, dedicated to the blessed memory of Vladimir Chizhukhin, deals with the problem of rescuing the blocks of carrier rockets for their subsequent use. The priority method is the use of aerospace parachute systems (ASPS), which are the lightest of all possible rescue systems. The possibility of using parachutes at space altitudes has been proven by the longterm practice of using them in M-100 meteorological rockets. Based on specific examples, numerical studies have been carried out on the possibility of using such a system, showing its great capabilities in combination with helicopter pick-up at the final stage of landing or with a rocket-dynamic soft-landing system.

Development of Fast and Soft Landing System for Quadcopter Drone using Fuzzy Logic Technology

Development of Fast and Soft Landing System for Quadcopter Drone using Fuzzy Logic Technology

Prediction of dependability for soft landing system with air dampers with Monte Carlo method

Prediction of dependability for soft landing system with air dampers with Monte Carlo method

Research on Unmanned Aerial Vehicles Autonomous Soft Landing Based on Optimal Control

This paper deals with the autonomous soft landing of unmanned helicopter aiming to enhance its application. Soft landing means to reduce the shock force upon ground during the helicopters land. Helicopter is a multi-input multi-output system and for which optimal control provides graceful and coordinated controls. Firstly, the experimental platform configuration for autonomous soft-landing system is introduced, which is based on the model helicopter. The time-varying gains and time-varying quadratic performance index Linear Quadratic control for autonomous soft landing of miniature helicopter is applied to unmanned helicopter. Simulation shows that the outputs of the system can respond the input signals accurately.

Overloading of Landing Based on the Deformation of the Lunar Lander

Along with the progress of sciences and technologies, a lot of explorations are taken in many countries or organizations in succession. Lunar, the natural satellite of the earth, become a focus of the space discovery again recently because of its abundant resource and high value in use. Lunar exploration is also one of the most important projects in China. A primary objective of the probe in lunar is to soft-land a manned spacecraft on the lunar surface. The soft-landing system is the key composition of the lunar lander. In the overall design of lunar lander, the analysis of touchdown dynamics during landing stage is an important work. The rigid-flexible coupling dynamics of a system with flexible cantilevers attached to the main lander is analyzed. The equations are derived from the subsystem method. Results show that the deformations of cantilevers have considerable effect on the overloading of the lunar lander system.