Lunar surface soft-landing analysis of a novel six-legged mobile lander with repetitive landing capacity

2021 ◽  
pp. 095440622199942
Author(s):  
Ke Yin ◽  
Qiao Sun ◽  
Feng Gao ◽  
Songlin Zhou
Keyword(s):  
Lunar Surface ◽  
Efficient Solution ◽  
Autonomous Robots ◽  
Lunar Gravity ◽  
Spring Stiffness ◽  
Effective Parameters ◽  
Soft Landing ◽  
Hybrid Mechanism ◽  
Planet Exploration ◽  
Buffer Structure

The autonomous robots consisting of an immovable lander and a rover are widely deployed to explore extraterrestrial planets. Two main drawbacks limit the development of this cooperative work mode: (1) it cannot perform soft-landing missions repeatedly on the planet, owing to the damage of buffer structure during soft-landing. (2) the rover’s detection area is restricted to the vicinity of the immovable lander. To overcome these problems, we have designed an innovative six-legged mobile lander with repetitive landing capacity, called “HexaMRL”, which integrates the functions of a lander and a rover including folding, deploying, repetitive landing, and walking. This novel robot’s legs adopted hybrid mechanism with active and passive compliance. Therefore, it remains to be a great challenge to analyze the robot soft-landing capacity which is determined by the parameters such as spring stiffness coefficient, damper damping coefficient, and initial tiptoe position. In order to solve the problem, the dynamic modeling and assessment criteria were established. The soft-landing process was analyzed through three numerical simulations using three sets of representative parameters based on dynamic model and the set of best effective parameters was chosen to apply in soft-landing experiment on a 5-DOF lunar gravity testing platform (5-DOF LGTP). The experiments were further verified that the selected parameters met the requirement of soft landing on the lunar surface. The HexaMRL provides novel insight for the next generation equipment for lunar exploration, which may be an efficient solution to the extraterrestrial planet exploration.

scholarly journals Lunar Radiometric Measurement Based on Observing China Chang’E-3 Lander with VLBI—First Insight

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
SongTao Han ◽  
ZhongKai Zhang ◽  
Jing Sun ◽  
JianFeng Cao ◽  
Lue Chen ◽  
...  
Keyword(s):  
Lunar Surface ◽  
Current Status ◽  
Accuracy Analysis ◽  
Radiometric Measurement ◽  
Soft Landing ◽  
Control Center ◽  
Lunar Reconnaissance Orbiter ◽  
International Vlbi Service ◽  
Lunar Lander

China Chang’E-3 performed soft landing at the plains of Sinus Iridum on lunar surface on December 14th 2013 successfully; it opened a new window for observing lunar surface with radiometric tracking which many lunar scientific researchers always pursue for. Since July 2014, OCEL (Observing Chang’E-3 Lander with VLBI) project has been conducted jointly by IVS (International VLBI Service of Geodesy and Astrometry) and BACC (Beijing Aerospace Control Center), a global IVS R&D network augmented with two China Deep Space Stations configured for OCEL. This paper presents the current status and preliminary result of the OCEL and mainly focuses on determination of the lander position, which is about 7 meter in height and 14 meter in plane of lunar surface with respect to LRO (Lunar Reconnaissance Orbiter). Based on accuracy analysis, further optimized OCEL sessions will make use of this target-of-opportunity, the Chang’E-3 lunar lander, as long as it is working. With higher accurate radiometric observables, more prospective contribution to earth and lunar science is expected by combining with LLR.

A Method of Earth Gravity Environment to Imitate LRV Steering on the Lunar Surface

2014 ◽  
Vol 575 ◽  
pp. 457-463
Author(s):  
Zhen Liu ◽  
Zhong Chao Liang ◽  
Hai Bo Gao ◽  
Liang Ding ◽  
Zong Quan Deng
Keyword(s):  
Lunar Surface ◽  
Dynamic Properties ◽  
Lunar Gravity ◽  
Earth Gravity ◽  
The Earth ◽  
Detection Tool ◽  
Earth Environment ◽  
Relationship Of ◽  
The Relationship ◽  
Parameter Relation

The lunar roving vehicle (LRV) is an important and indispensable detection tool that not only can travel far from the lunar module and transport, but also need ensure the astronauts safety when driving. Thus, the driving training for the astronauts on the earth is of great significance. However, the same vehicle has the different dynamic properties under the different gravities, and it is not able to train them with same vehicle on the earth. Therefore, a method of earth environment to imitate LRV steering on the lunar surface is required. In this study, to find out the relationship of the vehicles under different gravities, a handling dynamic model of the vehicles under different gravities is built, some parameter relation coefficients of vehicles under different gravities are carried out, and all parameters of the imitating vehicle for training and imitating on the earth are solved. Finally, the simulation results in Vortex show that, the imitating vehicle, which is changed parameters from LRV, can imitate a LRV steering under the lunar gravity on the earth.

scholarly journals COMPUTER VISION IN THE TELEOPERATION OF THE YUTU-2 ROVER

2020 ◽  
Vol V-3-2020 ◽  
pp. 595-602
Author(s):  
J. Wang ◽  
J. Li ◽  
S. Wang ◽  
T. Yu ◽  
Z. Rong ◽  
...  
Keyword(s):  
Computer Vision ◽  
Path Planning ◽  
Lunar Surface ◽  
Control Method ◽  
Landing Site ◽  
Slope Aspect ◽  
Soft Landing ◽  
Landing Point ◽  
Lunar Farside

Abstract. On January 3, 2019, the Chang'e-4 (CE-4) probe successfully landed in the Von Kármán crater inside the South Pole-Aitken (SPA) basin. With the support of a relay communication satellite "Queqiao" launched in 2018 and located at the Earth-Moon L2 liberation point, the lander and the Yutu-2 rover carried out in-situ exploration and patrol surveys, respectively, and were able to make a series of important scientific discoveries. Owing to the complexity and unpredictability of the lunar surface, teleoperation has become the most important control method for the operation of the rover. Computer vision is an important technology to support the teleoperation of the rover. During the powered descent stage and lunar surface exploration, teleoperation based on computer vision can effectively overcome many technical challenges, such as fast positioning of the landing point, high-resolution seamless mapping of the landing site, localization of the rover in the complex environment on the lunar surface, terrain reconstruction, and path planning. All these processes helped achieve the first soft landing, roving, and in-situ exploration on the lunar farside. This paper presents a high-precision positioning technology and positioning results of the landing point based on multi-source data, including orbital images and CE-4 descent images. The method and its results have been successfully applied in an actual engineering mission for the first time in China, providing important support for the topographical analysis of the landing site and mission planning for subsequent teleoperations. After landing, a 0.03 m resolution DOM was generated using the descent images and was used as one of the base maps for the overall rover path planning. Before each movement, the Yutu-2 rover controlled its hazard avoidance cameras (Hazcam), navigation cameras (Navcam), and panoramic cameras (Pancam) to capture stereo images of the lunar surface at different angles. Local digital elevation models (DEMs) with a 0.02 m resolution were routinely produced at each waypoint using the Navcam and Hazcam images. These DEMs were then used to design an obstacle recognition method and establish a model for calculating the slope, aspect, roughness, and visibility. Finally, in combination with the Yutu-2 rover mobility characteristics, a comprehensive cost map for path search was generated.By the end of the first 12 lunar days, the Yutu-2 rover has been working on the lunar farside for more than 300 days, greatly exceeding the projected service life. The rover was able to overcome the complex terrain on the lunar farside, and travelled a total distance of more than 300 m, achieving the "double three hundred" breakthrough. In future manned lunar landing and exploration of Mars by China, computer vision will play an integral role to support science target selection and scientific investigations, and will become an extremely important core technology for various engineering tasks.

Geometrical Guidance Algorithm for Soft Landing on Lunar Surface

2014 ◽  
Vol 47 (1) ◽  
pp. 14-19 ◽  
Author(s):  
M.P. Rijesh ◽  
G. Sijo ◽  
N.K. Philip ◽  
P. Natarajan
Keyword(s):  
Lunar Surface ◽  
Soft Landing ◽  
Guidance Algorithm

scholarly journals Chronology of the Basalt Units Surrounding Chang’e-4 Landing Area

2021 ◽  
Vol 14 (1) ◽  
pp. 49
Author(s):  
Zongyu Yue ◽  
Ke Shi ◽  
Gregory Michael ◽  
Kaichang Di ◽  
Sheng Gou ◽  
...  
Keyword(s):  
Lunar Surface ◽  
Measured Data ◽  
The Moon ◽  
Soft Landing ◽  
Size Frequency Distribution ◽  
Popular Method ◽  
Crater Size ◽  
Elevation Data ◽  
Geological Units

The Chang’e-4 (CE-4) lunar probe, the first soft landing spacecraft on the far side of the Moon, successfully landed in the Von Kármán crater on 3 January 2019. Geological studies of the landing area have been conducted and more intensive studies will be carried out with the in situ measured data. The chronological study of the maria basalt surrounding the CE-4 landing area is significant to the related studies. Currently, the crater size-frequency distribution (CSFD) technique is the most popular method to derive absolute model ages (AMAs) of geological units where no returned sample is available, and it has been widely used in dating maria basalt on the lunar surface. In this research, we first make a mosaic with multi-orbital Chang’e-2 (CE-2) images as a base map. Coupled with the elevation data and FeO content, nine representative areas of basalt units surrounding the CE-4 landing area are outlined and their AMAs are derived. The dating results of the nine basalt units indicate that the basalts erupted from 3.42 to 2.28 Ga ago in this area, a period much longer than derived by previous studies. The derived chronology of the above basalt units establishes a foundation for geological analysis of the returned CE-4 data.

scholarly journals Energy Absorption as a Predictor of Leg Impedance in Highly Trained Females

2006 ◽  
Vol 22 (3) ◽  
pp. 177-185 ◽  
Author(s):  
Anthony S. Kulas ◽  
Randy J. Schmitz ◽  
Sandra J. Shultz ◽  
Mary Allen Watson ◽  
David H. Perrin
Keyword(s):  
Energy Absorption ◽  
Linear Regression Analysis ◽  
Biomechanical Analysis ◽  
Spring Stiffness ◽  
Soft Landing ◽  
Stepwise Linear Regression Analysis ◽  
Stepwise Linear Regression ◽  
Stabilization Phase ◽  
The Relationship ◽  
Primary Predictor

Although leg spring stiffness represents active muscular recruitment of the lower extremity during dynamic tasks such as hopping and running, the joint-specific characteristics comprising the damping portion of this measure, leg impedance, are uncertain. The purpose of this investigation was to assess the relationship between leg impedance and energy absorption at the ankle, knee, and hip during early (impact) and late (stabilization) phases of landing. Twenty highly trained female dancers (age = 20.3 ± 1.4 years, height = 163.7 ± 6.0 cm, mass = 62.1 ± 8.1 kg) were instrumented for biomechanical analysis. Subjects performed three sets of double-leg landings from under preferred, stiff, and soft landing conditions. A stepwise linear regression analysis revealed that ankle and knee energy absorption at impact, and knee and hip energy absorption during the stabilization phases of landing explained 75.5% of the variance in leg impedance. The primary predictor of leg impedance was knee energy absorption during the stabilization phase, independently accounting for 55% of the variance. Future validation studies applying this regression model to other groups of individuals are warranted.

Real-time dynamic addressing for spacecraft soft landing in the lunar surface

2015 ◽  
Author(s):  
Liang He ◽  
Qinhu Ren ◽  
Yujian Feng ◽  
Jianhua Zhang ◽  
Sheng Liu ◽  
...  
Keyword(s):  
Real Time ◽  
Lunar Surface ◽  
Soft Landing ◽  
Time Dynamic
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