Reusable and flexible capturing of space debris is highly required in future aerospace technologies.A tendon-actuated flexible robotic arm is therefore proposed for capturing floating targets in this paper.Firstly,an ...Reusable and flexible capturing of space debris is highly required in future aerospace technologies.A tendon-actuated flexible robotic arm is therefore proposed for capturing floating targets in this paper.Firstly,an accurate dynamic model of the flexible robotic arm is established by using the absolute nodal coordinate formulation(ANCF)in the framework of the arbitrary Lagrangian-Eulerian(ALE)description and the natural coordinate formulation(NCF).The contact and self-contact dynamics of the flexible robotic arm when bending and grasping an object are considered via a fast contact detection approach.Then,the dynamic simulations of the flexible robotic arm for capturing floating targets are carried out to study the influence of the position,size,and mass of the target object on the grasping performance.Finally,a principle prototype of the tendon-actuated flexible robotic arm is manufactured to validate the dynamic model.The corresponding grasping experiments for objects of various shapes are also conducted to illustrate the excellent performance of the flexible robotic arm.展开更多
Accurate motion prediction of free-tumbling satellites is crucial for the success of capture operations.This paper proposes a two-step method to estimate the motion states and parameters of such satellites,thereby ena...Accurate motion prediction of free-tumbling satellites is crucial for the success of capture operations.This paper proposes a two-step method to estimate the motion states and parameters of such satellites,thereby enabling precise long-term motion prediction.This paper begins with a measurement of the system's degree of observability,quantified through the Empirical Observability Gramian(EOG).Based on this measurement,a batch processing algorithm is first employed to estimate the satellite's constant parameters offline.Subsequently,an online filtering algorithm,utilizing a minimal state set,fine-tunes these parameters and estimates the motion states in real time.This integrated approach significantly enhances both convergence properties and estimation accuracy,particularly for systems with poor observability.Utilizing the predicted long-term motion of the satellite,a composite evaluation metric is formulated to identify the optimal capture point and moment.The base pose of the space robot is then adjusted to ensure that the optimal capture point lies within the manipulator's dexterous workspace,which is determined through a pre-constructed capability map.The effectiveness of the proposed method is demonstrated through both simulation and experimental results.展开更多
Lithium-sulfur batteries(LSBs)are considered as the promising solution to replace conventional lithium-ion batteries due to satisfactory energy density.In recent times,the LSBs field has been found to face some diffic...Lithium-sulfur batteries(LSBs)are considered as the promising solution to replace conventional lithium-ion batteries due to satisfactory energy density.In recent times,the LSBs field has been found to face some difficulties in exploring practical applications in which cycling stability and cycle life are awful owing to the shuttling effect of lithium polysulfides(LiPSs)and low sulfur utilization.In this work,by synthesizing Co_(3)Se_(4) nanoparticles onto N-doped carbon(NC)polyhedra interconnected with carbon nanotubes(CNTs),NC@Co_(3)Se_(4)/CNTs is proposed as a multifunctional sulfur carrier.The Co_(3)Se_(4) nanoparticles fleetly catalyze the conversion of LiPSs and availably immobilize LiPSs.Meanwhile,the NC polyhedral skeleton enhances the electronic conductivity of active sulfur,while the CNTs facilitate Li+diffusion and supply a mass of conductive channels.Density-functional theory(DFT)calculations demonstrate the relevant mechanisms.That is to say,the NC@Co_(3)Se_(4)/CNTs benefit from the synergistic effect of Co_(3)Se_(4) nanoparticles(highly catalytic ability and strong adsorbability for LiPSs)and the special carbonaceous structure,rapidly converting LiPSs and inhibiting the shuttle of LiPSs.Therefore,lithium-sulfur battery assembled with S/NC@Co_(3)Se_(4)/CNTs cathode as well as nitrogen and sulfur co-doped carbon-coated polypropylene(N,S-C/PP)separator possesses a high initial discharge capacity of 1413 mAh·g-1 at 0.12C and persistently circulates for 1000 cycles at 1C with a capacity attenuation rate per cycle of 0.034%.This work provides a realistic idea for the use of transition metal selenide in the field of high-performance LSBs.展开更多
随着二氧化碳排放量的迅速攀升,经济、环境和能源的矛盾日益突出,发电行业作为典型的碳排放主体,正面临着低碳转型的迫切要求。文章构建了含电转气(power-to-gas,P2G)的碳捕集电厂,通过分析电厂的经济、环境和能源(economy-environment-...随着二氧化碳排放量的迅速攀升,经济、环境和能源的矛盾日益突出,发电行业作为典型的碳排放主体,正面临着低碳转型的迫切要求。文章构建了含电转气(power-to-gas,P2G)的碳捕集电厂,通过分析电厂的经济、环境和能源(economy-environment-energy,3E)特性,建立电厂的3E综合评价指标体系;为获取3E评价指标的相关数据,构建电厂的两阶段鲁棒优化调度模型,并利用约束生成算法进行求解;设计了组合赋权方法和基于灰色关联度分析的逼近理想解排序方法(grey relational analysis-technique for order preference by similarity to ideal soiution,GRA-POPSIS),形成3E综合评价模型。通过实际数据进行仿真分析,验证了在电-碳市场环境下,含P2G的碳捕集电厂相较于WT-GPPCC系统和WT-GFPP系统具有更好的经济、环境和能源综合效益,碳捕集、利用与封存(carbon capture,utilization and storage,CCUS)技术为系统带来的综合效益足以弥补其较高的运行成本,并且提出的3E综合评价模型具有良好的适用性。展开更多
为解决综合能源系统(integrated energy system,IES)盈余风电转化效率低、碳排放量大和存在源荷不确定性等问题,提出了一种基于信息间隙决策理论(info-gap decision theory,IGDT)的含氢能多元应用和碳捕集IES优化调度模型。首先,将电转...为解决综合能源系统(integrated energy system,IES)盈余风电转化效率低、碳排放量大和存在源荷不确定性等问题,提出了一种基于信息间隙决策理论(info-gap decision theory,IGDT)的含氢能多元应用和碳捕集IES优化调度模型。首先,将电转气细分为电解池、甲烷反应器两部分,并增设了氢燃料电池、掺氢热电联产和掺氢燃气锅炉等氢能应用,以充分发挥氢能的应用优势;其次,引入了储液式碳捕集,与氢能应用协同运行,同时以低碳经济为目标建立了系统优化调度模型;在此基础上,采用IGDT对源荷不确定性进行处理,根据风险态度制定了风险规避与机会寻求2种调度策略。结果表明:与不含氢能多元应用和碳捕集的IES模型相比,所提出的模型运行总成本下降了16.9%,碳排放量降低了29.4%,盈余风电转化效率提升了32.1百分点;风险规避策略可提高系统应对不确定性波动的能力,但成本会有一定程度的升高,而机会寻求策略则能充分利用有利不确定性来获得潜在效益,但需承担一定风险。展开更多
When the space robot captures a floating target, contact impact occurs inevitably and frequently between the manipulator hand and the target, which seriously impacts the position and attitude of the robot and grasping...When the space robot captures a floating target, contact impact occurs inevitably and frequently between the manipulator hand and the target, which seriously impacts the position and attitude of the robot and grasping security. ＂Dynamic grasping area＂ is introduced to describe the collision process of manipulator grasping target, and grasping area control equation is established. By analyzing the impact of grasping control parameters, base and target mass on the grasping process and combining the life experience, it is found that if the product of speed control parameter and dB adjustment parameter is close to but smaller than the minimum grasping speed, collision impact in the grasping process could be reduced greatly, and then an ideal grasping strategy is proposed. Simulation results indicate that during the same period, the strategy grasping is superior to the accelerating grasping, in that the amplitude of impact force is reduced to 20%, and the attitude control torque is reduced to 15%, and the impact on the robot is eliminated significantly. The results would have important academic value and engineering significance.展开更多
基金funded by the"14th Five-Year Plan"Civil Aerospace Pre-research Project of China(Grant No.D010301).
文摘Reusable and flexible capturing of space debris is highly required in future aerospace technologies.A tendon-actuated flexible robotic arm is therefore proposed for capturing floating targets in this paper.Firstly,an accurate dynamic model of the flexible robotic arm is established by using the absolute nodal coordinate formulation(ANCF)in the framework of the arbitrary Lagrangian-Eulerian(ALE)description and the natural coordinate formulation(NCF).The contact and self-contact dynamics of the flexible robotic arm when bending and grasping an object are considered via a fast contact detection approach.Then,the dynamic simulations of the flexible robotic arm for capturing floating targets are carried out to study the influence of the position,size,and mass of the target object on the grasping performance.Finally,a principle prototype of the tendon-actuated flexible robotic arm is manufactured to validate the dynamic model.The corresponding grasping experiments for objects of various shapes are also conducted to illustrate the excellent performance of the flexible robotic arm.
基金supported by the National Natural Science Foundation of China(Nos.62403171,T2388101)。
文摘Accurate motion prediction of free-tumbling satellites is crucial for the success of capture operations.This paper proposes a two-step method to estimate the motion states and parameters of such satellites,thereby enabling precise long-term motion prediction.This paper begins with a measurement of the system's degree of observability,quantified through the Empirical Observability Gramian(EOG).Based on this measurement,a batch processing algorithm is first employed to estimate the satellite's constant parameters offline.Subsequently,an online filtering algorithm,utilizing a minimal state set,fine-tunes these parameters and estimates the motion states in real time.This integrated approach significantly enhances both convergence properties and estimation accuracy,particularly for systems with poor observability.Utilizing the predicted long-term motion of the satellite,a composite evaluation metric is formulated to identify the optimal capture point and moment.The base pose of the space robot is then adjusted to ensure that the optimal capture point lies within the manipulator's dexterous workspace,which is determined through a pre-constructed capability map.The effectiveness of the proposed method is demonstrated through both simulation and experimental results.
基金supported by the National Natural Science Foundation of China(Nos.52130101 and 52271217)the Project of Science and Technology Development Plan of Jilin Province in China(Nos.20210402058GH,20220201114GX).
文摘Lithium-sulfur batteries(LSBs)are considered as the promising solution to replace conventional lithium-ion batteries due to satisfactory energy density.In recent times,the LSBs field has been found to face some difficulties in exploring practical applications in which cycling stability and cycle life are awful owing to the shuttling effect of lithium polysulfides(LiPSs)and low sulfur utilization.In this work,by synthesizing Co_(3)Se_(4) nanoparticles onto N-doped carbon(NC)polyhedra interconnected with carbon nanotubes(CNTs),NC@Co_(3)Se_(4)/CNTs is proposed as a multifunctional sulfur carrier.The Co_(3)Se_(4) nanoparticles fleetly catalyze the conversion of LiPSs and availably immobilize LiPSs.Meanwhile,the NC polyhedral skeleton enhances the electronic conductivity of active sulfur,while the CNTs facilitate Li+diffusion and supply a mass of conductive channels.Density-functional theory(DFT)calculations demonstrate the relevant mechanisms.That is to say,the NC@Co_(3)Se_(4)/CNTs benefit from the synergistic effect of Co_(3)Se_(4) nanoparticles(highly catalytic ability and strong adsorbability for LiPSs)and the special carbonaceous structure,rapidly converting LiPSs and inhibiting the shuttle of LiPSs.Therefore,lithium-sulfur battery assembled with S/NC@Co_(3)Se_(4)/CNTs cathode as well as nitrogen and sulfur co-doped carbon-coated polypropylene(N,S-C/PP)separator possesses a high initial discharge capacity of 1413 mAh·g-1 at 0.12C and persistently circulates for 1000 cycles at 1C with a capacity attenuation rate per cycle of 0.034%.This work provides a realistic idea for the use of transition metal selenide in the field of high-performance LSBs.
文摘随着二氧化碳排放量的迅速攀升,经济、环境和能源的矛盾日益突出,发电行业作为典型的碳排放主体,正面临着低碳转型的迫切要求。文章构建了含电转气(power-to-gas,P2G)的碳捕集电厂,通过分析电厂的经济、环境和能源(economy-environment-energy,3E)特性,建立电厂的3E综合评价指标体系;为获取3E评价指标的相关数据,构建电厂的两阶段鲁棒优化调度模型,并利用约束生成算法进行求解;设计了组合赋权方法和基于灰色关联度分析的逼近理想解排序方法(grey relational analysis-technique for order preference by similarity to ideal soiution,GRA-POPSIS),形成3E综合评价模型。通过实际数据进行仿真分析,验证了在电-碳市场环境下,含P2G的碳捕集电厂相较于WT-GPPCC系统和WT-GFPP系统具有更好的经济、环境和能源综合效益,碳捕集、利用与封存(carbon capture,utilization and storage,CCUS)技术为系统带来的综合效益足以弥补其较高的运行成本,并且提出的3E综合评价模型具有良好的适用性。
文摘为解决综合能源系统(integrated energy system,IES)盈余风电转化效率低、碳排放量大和存在源荷不确定性等问题,提出了一种基于信息间隙决策理论(info-gap decision theory,IGDT)的含氢能多元应用和碳捕集IES优化调度模型。首先,将电转气细分为电解池、甲烷反应器两部分,并增设了氢燃料电池、掺氢热电联产和掺氢燃气锅炉等氢能应用,以充分发挥氢能的应用优势;其次,引入了储液式碳捕集,与氢能应用协同运行,同时以低碳经济为目标建立了系统优化调度模型;在此基础上,采用IGDT对源荷不确定性进行处理,根据风险态度制定了风险规避与机会寻求2种调度策略。结果表明:与不含氢能多元应用和碳捕集的IES模型相比,所提出的模型运行总成本下降了16.9%,碳排放量降低了29.4%,盈余风电转化效率提升了32.1百分点;风险规避策略可提高系统应对不确定性波动的能力,但成本会有一定程度的升高,而机会寻求策略则能充分利用有利不确定性来获得潜在效益,但需承担一定风险。
基金Program for Innovative Research Team in University(IRT520)CAST of China (20090703)
文摘When the space robot captures a floating target, contact impact occurs inevitably and frequently between the manipulator hand and the target, which seriously impacts the position and attitude of the robot and grasping security. ＂Dynamic grasping area＂ is introduced to describe the collision process of manipulator grasping target, and grasping area control equation is established. By analyzing the impact of grasping control parameters, base and target mass on the grasping process and combining the life experience, it is found that if the product of speed control parameter and dB adjustment parameter is close to but smaller than the minimum grasping speed, collision impact in the grasping process could be reduced greatly, and then an ideal grasping strategy is proposed. Simulation results indicate that during the same period, the strategy grasping is superior to the accelerating grasping, in that the amplitude of impact force is reduced to 20%, and the attitude control torque is reduced to 15%, and the impact on the robot is eliminated significantly. The results would have important academic value and engineering significance.
