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 ...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.展开更多
Focused on the dynamics problems of a lunar lander during landing process, the whole process was analysed in detail, and the linear elastic model of the moon soil was established by means of experiments-analogic metho...Focused on the dynamics problems of a lunar lander during landing process, the whole process was analysed in detail, and the linear elastic model of the moon soil was established by means of experiments-analogic method. Combining the way of elastic impact with the way of velocity replacement, the dynamics model of damping free vibration dynamics model with 3-degree of freedom(DOF) for lunar lander is obtained according to the vibration mechanics elementary theory. Based on Lagrange equations and the energy principle, the damping free vibration differential equations for the lunar lander with 3-DOF are derived and the equations are solved in simulation ways by means of ADAMS software. The conclusions obtained can be used for the design and manufacture of lunar lander.展开更多
Safe soft landing of the lander is vital to the Mars surface exploration mission. Analysis and verification of the landing stability under uncertain terrain play an important role in lander design. However, the effect...Safe soft landing of the lander is vital to the Mars surface exploration mission. Analysis and verification of the landing stability under uncertain terrain play an important role in lander design. However, the effect of uncertain terrain is ignored in most existing studies, making the analysis incomprehensive and increasing the risk of landing failure in practice. In this paper, a Mars lander with 10 attitude control thrusters is introduced and its dynamics model is then established considering plastic deformation parts and nonlinear contact forces. The effectiveness and accuracy of the dynamics modeling method are verified by experiments with an average relative error of 10%.In order to carry out the dynamics simulation with high-fidelity terrain, a terrain generation method based on statistical data is proposed. Through Monte Carlo simulation under a 50 m × 50 m randomly generated landing terrain, the stability of the lander and the effects of attitude control thrusters are analyzed. The results show that the failure rate is 5.5%, in which the primary failure forms are overturning and abnormal attitude. When the landing simulations are repeated without thrusters, the stable ratio decreases from 94.5% to 90.7%, suggesting the positive effects of attitude control thrusters in improving landing stability under rough terrain.展开更多
The displacement field generated by aftershocks in Landers earthquake fault zone and its adjacent areas is calculated in this study. The result is compared with the displacement field of the main shock calculated by c...The displacement field generated by aftershocks in Landers earthquake fault zone and its adjacent areas is calculated in this study. The result is compared with the displacement field of the main shock calculated by co-seismic slip model of Wald and Heaton (1994). The result shows that the direction of displacement generated by aftershocks in Landers seismic fault plane and its adjacent areas is consistent with that generated by main shock. The rupture of aftershock is generally inherited from main shock. The displacement generated by aftershocks is up to an order of centimeter and can be measured by GPS sites nearby. So when we use geodetic data measured after earthquake to study the geophysical problems such as crustal viscosity structure, afterslip distribution, etc., only the displacement field generated by aftershocks considered, can uncertainty be reduced to minimum and realistic result be obtained.展开更多
The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characte...The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characteristics during the impact process.The conventional footpad is typically designed with an aluminum honeycomb structure that dissipates energy through plastic deformation.Nevertheless,its effectiveness in providing cushioning and energy absorption becomes significantly compromised when the structure is crushed,rendering it unusable for reusable landers in the future.This study presents a methodology for designing and evaluating structural energy absorption systems incorporating recoverable strain constraints of shape memory alloys(SMA).The topological configuration of the energy absorbing structure is derived using an equivalent static load method(ESL),and three lightweight footpad designs featuring honeycomb-like Ni-Ti shape memory alloys structures and having variable stiffness skins are proposed.To verify the accuracy of the numerical modelling,a honeycomb-like structure subjected to compression load is modeled and then compared with experimental results.Moreover,the influence of the configurations and thickness distribution of the proposed structures on their energy absorption performance is comprehensively evaluated using finite element simulations.The results demonstrate that the proposed design approach effectively regulates the strain threshold to maintain the SMA within the constraint of maximum recoverable strain,resulting in a structural energy absorption capacity of 362 J/kg with a crushing force efficiency greater than 63%.展开更多
The Chang＇e-3 （CE-3） lander and rover mission to the Moon was an in- termediate step in China＇s lunar exploration program, which will be followed by a sample return mission. The lander was equipped with a number o...The Chang＇e-3 （CE-3） lander and rover mission to the Moon was an in- termediate step in China＇s lunar exploration program, which will be followed by a sample return mission. The lander was equipped with a number of remote-sensing instruments including a pair of cameras （Landing Camera and Terrain Camera） for recording the landing process and surveying terrain, an extreme ultraviolet camera for monitoring activities in the Earth＇s plasmasphere, and a first-ever Moon-based ultravi- olet telescope for astronomical observations. The Yutu rover successfully carried out close-up observations with the Panoramic Camera, mineralogical investigations with the VIS-NIR Imaging Spectrometer, study of elemental abundances with the Active Particle-induced X-ray Spectrometer, and pioneering measurements of the lunar sub- surface with Lunar Penetrating Radar. This special issue provides a collection of key information on the instrumental designs, calibration methods and data processing pro- cedures used by these experiments with a perspective of facilitating further analyses of scientific data from CE-3 in preparation for future missions.展开更多
The lander with orientation capability is of fundamental importance for the“Returning”mission because its body can be the base with a suitable launching angle for the ascender lifting off.This paper proposes the con...The lander with orientation capability is of fundamental importance for the“Returning”mission because its body can be the base with a suitable launching angle for the ascender lifting off.This paper proposes the conceptual design and verification of Landers with Orientation Capability(LOCs).Firstly,the topological composition of the lander is analyzed and expressed in the form of Lie group,which provides the fundamental principle for the type synthesis of LOCs.Then,the type synthesis approach for designing LOCs is proposed,which includes designing the Equivalent Parallel Mechanism(EPM)and the auxiliary limbs.Numerous mechanisms of LOCs with twodimensional rotational motions are obtained based on the type synthesis approach by developing and combining the EPMs and auxiliary limbs.Afterward,kinematics and Jacobian matrix of a typical legged lander are developed,the workspace is analyzed,singularity configurations are analyzed based on the wrench graph method,and finally,the orientation capability is analyzed.The pitch and yaw angle reach 17.5°,considering the permissible range of joints.The proposed types of LOCs offer potential candidate for the“Returning”mission of the exploration mission.展开更多
The colonization of underwater environments by exotic seaweeds is causing major ecological problems around the world.This project,referred to AMALIA,aims to transform this current ocean threat into an opportunity by a...The colonization of underwater environments by exotic seaweeds is causing major ecological problems around the world.This project,referred to AMALIA,aims to transform this current ocean threat into an opportunity by adding value to the macroalgae present off the northwest of the Iberian Peninsula.To do so and to observe the presence of seaweeds in situ,an ocean modular submersible platform was developed.This platform was designed to be capable of detecting and surveying surges of invasive seaweeds while withstanding sea conditions.Conceptual designs followed by a screening process were performed,taking into consideration criteria such as operational range and modularity.An open-frame lander was considered and further developed using buckling criteria.In parallel,a state-of-the-art monitoring system was created using spectral imaging,allowing for the future creation of a macroalgae identification system.In addition,sensorial systems for characterizing growth conditions were introduced.Laboratory trials were executed to assess the capability of the system,and sea trials are currently being performed.Numerical simulations and laboratory trials indicate that the structure is fully capable of being deployed for shallow-water environments with a state-of-the-art invasive seaweed monitoring system while maintaining a high degree of modularity.展开更多
To explore hostile extraterrestrial landforms and construct an engineering prototype,this paper presents the task-oriented topology system synthesis of reconfigurable legged mobile lander(ReLML)with three operation mo...To explore hostile extraterrestrial landforms and construct an engineering prototype,this paper presents the task-oriented topology system synthesis of reconfigurable legged mobile lander(ReLML)with three operation modes from adjusting,landing,to roving.Compared with our preceding works,the adjusting mode with three rotations(3R)provides a totally novel exploration approach to geometrically matching and securely arriving at complex terrains dangerous to visit currently;the landing mode is redefined by two rotations one translation(2R1T),identical with the tried-and-tested Apollo and Chang'E landers to enhance survivability via reasonable touchdown buffering motion;roving mode also utilizes 2R1T motion for good motion and force properties.The reconfigurable mechanism theory is first brought into synthesizing legged mobile lander integrating active and passive metamorphoses,composed of two types of metamorphic joints and metamorphic execution and transmission mechanisms.To reveal metamorphic principles with multiple finite motions,the finite screw theory is developed to present the procedure from unified mathematical representation,modes and source phase derivations,metamorphic joint and limb design,to final structure assembly.To identify the prototype topology,the 3D optimal selection matrix method is proposed considering three operation modes,five evaluation criteria,and two topological subsystems.Finally,simulation verifies the whole task implementation process to ensure the reasonability of design.展开更多
Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander ...Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.展开更多
Chang’e 3 lunar lander conducted extended tests on the surface of the moon after awakening from its dormancy.It was announced in the late of January that the pointing mechanism of the cameras onboard Chang’e 3 under...Chang’e 3 lunar lander conducted extended tests on the surface of the moon after awakening from its dormancy.It was announced in the late of January that the pointing mechanism of the cameras onboard Chang’e 3 underwent extended tests to confirm the moving performance and limit switch triggering of the pointing mechanism under various status while pitching,moving forward and backward.According to the analysis derived from the展开更多
Aground firing test of the Chang'e 3 lander was conducted recently to check the mechanical performance of the spacecraft. The test was vital before the propulsion system test of the Chang'e 3 lander and was al...Aground firing test of the Chang'e 3 lander was conducted recently to check the mechanical performance of the spacecraft. The test was vital before the propulsion system test of the Chang'e 3 lander and was also a very important precondition to verify whether the propulsion system design could meet the requirements for in-orbit operation.展开更多
Small bodies have the characteristics of noncooperative,irregular gravity,and complex terrain on the surface,which cause difficulties in successful landing for conventional landers.In this paper,a multinode flexible l...Small bodies have the characteristics of noncooperative,irregular gravity,and complex terrain on the surface,which cause difficulties in successful landing for conventional landers.In this paper,a multinode flexible lander is put forward to address the problem.The dynamics of this new lander are constructed based on the port-Hamilton framework.The trajectory-tracking formation controller for the lander is designed in a passive way.The proposed dynamics and controller are further validated through numerical simulations.This research presents a fresh concept that holds inspiration for future design involving small-body landers.展开更多
For the needs of manned landing,station construction,and material transfer in future lunar exploration missions,the paper proposes a landing–moving integrated gear(LMIG)for mobile lunar lander(MLL),establishes and op...For the needs of manned landing,station construction,and material transfer in future lunar exploration missions,the paper proposes a landing–moving integrated gear(LMIG)for mobile lunar lander(MLL),establishes and optimizes the models of cushioning energy-absorbing and movement planning,respectively,and conducts the prototype tests.First,the design requirements of LMIG are given,and the system composition of LMIG and the configuration design of each subsystem are introduced.Second,the effective energy-absorbing model of the aluminum honeycomb is established and experimentally verified,a three-stage aluminum honeycomb buffer is designed and experimentally verified,and the buffer mechanism of LMIG is verified by simulations under various landing conditions.Furthermore,the kinematic and dynamic models of LMIG are established,the moving gait is designed by the center of gravity trajectory planning method,and the driving trajectory during the stepping process is optimized with the goal of minimal jerk of motion.Finally,a cushioning test prototype and a walking test scaled prototype of LMIG are developed,and single leg drop test and ground walking test are carried out.The results show that the established model of LMIG is reasonable,the designed buffer and gait of LMIG are effective,the developed prototypes of LMIG have good cushioning and movement performance,the LMIG’s maximum value of overload acceleration is 6.5g,and the moving speed is 108 m/h,which meets the design requirements.展开更多
The primary mode of extraterrestrial exploration is a robotic system comprising a lander and a rover.However,the lander is immovable,and the rover has a restrictive detection area because of the difficulties of reachi...The primary mode of extraterrestrial exploration is a robotic system comprising a lander and a rover.However,the lander is immovable,and the rover has a restrictive detection area because of the difficulties of reaching complex terrains,such as those with deep craters.In this study,a six-legged mobile repetitive lander with landing and walking functions is designed to solve these problems.First,a six-legged mobile repetitive lander and its structure are introduced.Then,a soft-landing method based on compliance control and optimal force control is addressed to control the landing process.Finally,the experiments are conducted to validate the soft-landing method and its performances.Results show that the soft-landing method for the six-legged mobile repetitive lander can successfully control the joint torques and solve the soft-landing problem on complex terrains,such as those with steps and slopes.展开更多
基金HI-tech Research and Development Program of China
文摘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.
文摘Focused on the dynamics problems of a lunar lander during landing process, the whole process was analysed in detail, and the linear elastic model of the moon soil was established by means of experiments-analogic method. Combining the way of elastic impact with the way of velocity replacement, the dynamics model of damping free vibration dynamics model with 3-degree of freedom(DOF) for lunar lander is obtained according to the vibration mechanics elementary theory. Based on Lagrange equations and the energy principle, the damping free vibration differential equations for the lunar lander with 3-DOF are derived and the equations are solved in simulation ways by means of ADAMS software. The conclusions obtained can be used for the design and manufacture of lunar lander.
基金supported by the Joint Fund of Advanced Aerospace Manufacturing Technology Research(No.U2037602)。
文摘Safe soft landing of the lander is vital to the Mars surface exploration mission. Analysis and verification of the landing stability under uncertain terrain play an important role in lander design. However, the effect of uncertain terrain is ignored in most existing studies, making the analysis incomprehensive and increasing the risk of landing failure in practice. In this paper, a Mars lander with 10 attitude control thrusters is introduced and its dynamics model is then established considering plastic deformation parts and nonlinear contact forces. The effectiveness and accuracy of the dynamics modeling method are verified by experiments with an average relative error of 10%.In order to carry out the dynamics simulation with high-fidelity terrain, a terrain generation method based on statistical data is proposed. Through Monte Carlo simulation under a 50 m × 50 m randomly generated landing terrain, the stability of the lander and the effects of attitude control thrusters are analyzed. The results show that the failure rate is 5.5%, in which the primary failure forms are overturning and abnormal attitude. When the landing simulations are repeated without thrusters, the stable ratio decreases from 94.5% to 90.7%, suggesting the positive effects of attitude control thrusters in improving landing stability under rough terrain.
基金National Natural Science Foundation of China (40374012) and National Basic Key Project (2002CCA04500).
文摘The displacement field generated by aftershocks in Landers earthquake fault zone and its adjacent areas is calculated in this study. The result is compared with the displacement field of the main shock calculated by co-seismic slip model of Wald and Heaton (1994). The result shows that the direction of displacement generated by aftershocks in Landers seismic fault plane and its adjacent areas is consistent with that generated by main shock. The rupture of aftershock is generally inherited from main shock. The displacement generated by aftershocks is up to an order of centimeter and can be measured by GPS sites nearby. So when we use geodetic data measured after earthquake to study the geophysical problems such as crustal viscosity structure, afterslip distribution, etc., only the displacement field generated by aftershocks considered, can uncertainty be reduced to minimum and realistic result be obtained.
基金Supported by Fundamental Research Funds for the Central Universities of China(Grant No.2021JBM021)National Natural Science Foundation of China(Grant Nos.52202431,52172353).
文摘The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characteristics during the impact process.The conventional footpad is typically designed with an aluminum honeycomb structure that dissipates energy through plastic deformation.Nevertheless,its effectiveness in providing cushioning and energy absorption becomes significantly compromised when the structure is crushed,rendering it unusable for reusable landers in the future.This study presents a methodology for designing and evaluating structural energy absorption systems incorporating recoverable strain constraints of shape memory alloys(SMA).The topological configuration of the energy absorbing structure is derived using an equivalent static load method(ESL),and three lightweight footpad designs featuring honeycomb-like Ni-Ti shape memory alloys structures and having variable stiffness skins are proposed.To verify the accuracy of the numerical modelling,a honeycomb-like structure subjected to compression load is modeled and then compared with experimental results.Moreover,the influence of the configurations and thickness distribution of the proposed structures on their energy absorption performance is comprehensively evaluated using finite element simulations.The results demonstrate that the proposed design approach effectively regulates the strain threshold to maintain the SMA within the constraint of maximum recoverable strain,resulting in a structural energy absorption capacity of 362 J/kg with a crushing force efficiency greater than 63%.
文摘The Chang＇e-3 （CE-3） lander and rover mission to the Moon was an in- termediate step in China＇s lunar exploration program, which will be followed by a sample return mission. The lander was equipped with a number of remote-sensing instruments including a pair of cameras （Landing Camera and Terrain Camera） for recording the landing process and surveying terrain, an extreme ultraviolet camera for monitoring activities in the Earth＇s plasmasphere, and a first-ever Moon-based ultravi- olet telescope for astronomical observations. The Yutu rover successfully carried out close-up observations with the Panoramic Camera, mineralogical investigations with the VIS-NIR Imaging Spectrometer, study of elemental abundances with the Active Particle-induced X-ray Spectrometer, and pioneering measurements of the lunar sub- surface with Lunar Penetrating Radar. This special issue provides a collection of key information on the instrumental designs, calibration methods and data processing pro- cedures used by these experiments with a perspective of facilitating further analyses of scientific data from CE-3 in preparation for future missions.
基金partial financial support under the projects from the National Natural Science Foundation of China(Nos.51735009 and 51905338)the State Key Laboratory of Mechanical System and Vibration,China(No.MSVZD-2016-08)the China Postdoctoral Science Foundation(No.2019M651487)。
文摘The lander with orientation capability is of fundamental importance for the“Returning”mission because its body can be the base with a suitable launching angle for the ascender lifting off.This paper proposes the conceptual design and verification of Landers with Orientation Capability(LOCs).Firstly,the topological composition of the lander is analyzed and expressed in the form of Lie group,which provides the fundamental principle for the type synthesis of LOCs.Then,the type synthesis approach for designing LOCs is proposed,which includes designing the Equivalent Parallel Mechanism(EPM)and the auxiliary limbs.Numerous mechanisms of LOCs with twodimensional rotational motions are obtained based on the type synthesis approach by developing and combining the EPMs and auxiliary limbs.Afterward,kinematics and Jacobian matrix of a typical legged lander are developed,the workspace is analyzed,singularity configurations are analyzed based on the wrench graph method,and finally,the orientation capability is analyzed.The pitch and yaw angle reach 17.5°,considering the permissible range of joints.The proposed types of LOCs offer potential candidate for the“Returning”mission of the exploration mission.
基金supported by the European Union under Grant No. EASME/EMFF/2016/1.2.1.4/03/SI2.750419the AMALIA-Algae-to-Market Lab Ideas Project。
文摘The colonization of underwater environments by exotic seaweeds is causing major ecological problems around the world.This project,referred to AMALIA,aims to transform this current ocean threat into an opportunity by adding value to the macroalgae present off the northwest of the Iberian Peninsula.To do so and to observe the presence of seaweeds in situ,an ocean modular submersible platform was developed.This platform was designed to be capable of detecting and surveying surges of invasive seaweeds while withstanding sea conditions.Conceptual designs followed by a screening process were performed,taking into consideration criteria such as operational range and modularity.An open-frame lander was considered and further developed using buckling criteria.In parallel,a state-of-the-art monitoring system was created using spectral imaging,allowing for the future creation of a macroalgae identification system.In addition,sensorial systems for characterizing growth conditions were introduced.Laboratory trials were executed to assess the capability of the system,and sea trials are currently being performed.Numerical simulations and laboratory trials indicate that the structure is fully capable of being deployed for shallow-water environments with a state-of-the-art invasive seaweed monitoring system while maintaining a high degree of modularity.
基金Supported by National Natural Science Foundation of China(Grant No.51735009)State Key Lab of Mechanical System and Vibration Project of China(Grant No.MSVZD202008)National Aerospace Science Foundation of China(040102).
文摘To explore hostile extraterrestrial landforms and construct an engineering prototype,this paper presents the task-oriented topology system synthesis of reconfigurable legged mobile lander(ReLML)with three operation modes from adjusting,landing,to roving.Compared with our preceding works,the adjusting mode with three rotations(3R)provides a totally novel exploration approach to geometrically matching and securely arriving at complex terrains dangerous to visit currently;the landing mode is redefined by two rotations one translation(2R1T),identical with the tried-and-tested Apollo and Chang'E landers to enhance survivability via reasonable touchdown buffering motion;roving mode also utilizes 2R1T motion for good motion and force properties.The reconfigurable mechanism theory is first brought into synthesizing legged mobile lander integrating active and passive metamorphoses,composed of two types of metamorphic joints and metamorphic execution and transmission mechanisms.To reveal metamorphic principles with multiple finite motions,the finite screw theory is developed to present the procedure from unified mathematical representation,modes and source phase derivations,metamorphic joint and limb design,to final structure assembly.To identify the prototype topology,the 3D optimal selection matrix method is proposed considering three operation modes,five evaluation criteria,and two topological subsystems.Finally,simulation verifies the whole task implementation process to ensure the reasonability of design.
基金Sponsored by the Project on Absorption of Intellects by Institutions of Higher Education for Academic Disciplinary Innovations(Grant No. B07018)
文摘Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.
文摘Chang’e 3 lunar lander conducted extended tests on the surface of the moon after awakening from its dormancy.It was announced in the late of January that the pointing mechanism of the cameras onboard Chang’e 3 underwent extended tests to confirm the moving performance and limit switch triggering of the pointing mechanism under various status while pitching,moving forward and backward.According to the analysis derived from the
文摘Aground firing test of the Chang'e 3 lander was conducted recently to check the mechanical performance of the spacecraft. The test was vital before the propulsion system test of the Chang'e 3 lander and was also a very important precondition to verify whether the propulsion system design could meet the requirements for in-orbit operation.
基金supported by the National Key R&D Program(grant number 2019YFA0706500)the National Natural Science Foundation of China(grant number 62273118)National defense basic research projects(grant numbers JCKY2021603B030,JCKY2020903B002).
文摘Small bodies have the characteristics of noncooperative,irregular gravity,and complex terrain on the surface,which cause difficulties in successful landing for conventional landers.In this paper,a multinode flexible lander is put forward to address the problem.The dynamics of this new lander are constructed based on the port-Hamilton framework.The trajectory-tracking formation controller for the lander is designed in a passive way.The proposed dynamics and controller are further validated through numerical simulations.This research presents a fresh concept that holds inspiration for future design involving small-body landers.
基金the National Science and Technology Special Projects(grant nos.2021-JCJQ-JJ-0233,23-TQ01-04-ZT-01-017,and D050202)the Fundamental Research Funds for the Central Universities(grant no.NT2022026)National Natural Science Foundation of China(General Program,grant no.52075242)for the funding of this work.
文摘For the needs of manned landing,station construction,and material transfer in future lunar exploration missions,the paper proposes a landing–moving integrated gear(LMIG)for mobile lunar lander(MLL),establishes and optimizes the models of cushioning energy-absorbing and movement planning,respectively,and conducts the prototype tests.First,the design requirements of LMIG are given,and the system composition of LMIG and the configuration design of each subsystem are introduced.Second,the effective energy-absorbing model of the aluminum honeycomb is established and experimentally verified,a three-stage aluminum honeycomb buffer is designed and experimentally verified,and the buffer mechanism of LMIG is verified by simulations under various landing conditions.Furthermore,the kinematic and dynamic models of LMIG are established,the moving gait is designed by the center of gravity trajectory planning method,and the driving trajectory during the stepping process is optimized with the goal of minimal jerk of motion.Finally,a cushioning test prototype and a walking test scaled prototype of LMIG are developed,and single leg drop test and ground walking test are carried out.The results show that the established model of LMIG is reasonable,the designed buffer and gait of LMIG are effective,the developed prototypes of LMIG have good cushioning and movement performance,the LMIG’s maximum value of overload acceleration is 6.5g,and the moving speed is 108 m/h,which meets the design requirements.
基金supported by the National Natural Science Foundation of China(Grant No.92248303)the Startup Fund for Young Faculty at Shanghai Jiao Tong University.
文摘The primary mode of extraterrestrial exploration is a robotic system comprising a lander and a rover.However,the lander is immovable,and the rover has a restrictive detection area because of the difficulties of reaching complex terrains,such as those with deep craters.In this study,a six-legged mobile repetitive lander with landing and walking functions is designed to solve these problems.First,a six-legged mobile repetitive lander and its structure are introduced.Then,a soft-landing method based on compliance control and optimal force control is addressed to control the landing process.Finally,the experiments are conducted to validate the soft-landing method and its performances.Results show that the soft-landing method for the six-legged mobile repetitive lander can successfully control the joint torques and solve the soft-landing problem on complex terrains,such as those with steps and slopes.
