Joint clearance,as an important stochastic factor,can significantly deteriorate positioning and repeatability accuracies and lower assembly quality of a 6-DOF docking mechanism.Considering pose accuracy with tradition...Joint clearance,as an important stochastic factor,can significantly deteriorate positioning and repeatability accuracies and lower assembly quality of a 6-DOF docking mechanism.Considering pose accuracy with traditional error model that possesses inherent imprecision,both probabilistic and deterministic approaches based on forward kinematics are presented to analyze comprehensive pose error(CPE)in simulation.Results indicate an identical trend emerges for each CPE with both approaches,and both CPEs perform opposite variations as the moving platform upgrades.The findings provide theoretical reference for refinement of assembly quality evaluation of this mechanism.展开更多
Current-carrying sliding is widely applied in aerospace equipment,but it is limited by the poor lubricity of the present materials and the unclear tribological mechanism.This study demonstrated the potential of MoS_(2...Current-carrying sliding is widely applied in aerospace equipment,but it is limited by the poor lubricity of the present materials and the unclear tribological mechanism.This study demonstrated the potential of MoS_(2)-based materials with excellent lubricity as space sliding electrical contact materials by doping Ti to improve its conductivity.The tribological behavior of MoS_(2)-Ti films under current-carrying sliding in vacuum was studied by establishing a simulation evaluating device.Moreover,the noncurrent-carrying sliding and static current-carrying experiments in vacuum were carried out for comparison to understand the tribological mechanism.In addition to mechanical wear,the current-induced arc erosion and thermal effect take important roles in accelerating the wear.Arc erosion is caused by the accumulation of electric charge,which is related to the conductivity of the film.While the current-thermal effect softens the film,causing strong adhesive wear,and good conductivity and the large contact area are beneficial for minimizing the thermal effect.So the moderate hardness and good conductivity of MoS_(2)-Ti film contribute to its excellent current-carrying tribological behavior in vacuum,showing a significant advantage compared with the traditional ones.展开更多
基金supported by the National Defense Basic Scientific Research Program(No.A0320110019)the Shanghai Science and Technology Innovation Action Plan(No.11DZ1120800)
文摘Joint clearance,as an important stochastic factor,can significantly deteriorate positioning and repeatability accuracies and lower assembly quality of a 6-DOF docking mechanism.Considering pose accuracy with traditional error model that possesses inherent imprecision,both probabilistic and deterministic approaches based on forward kinematics are presented to analyze comprehensive pose error(CPE)in simulation.Results indicate an identical trend emerges for each CPE with both approaches,and both CPEs perform opposite variations as the moving platform upgrades.The findings provide theoretical reference for refinement of assembly quality evaluation of this mechanism.
基金supported by the National Natural Science Foundation of China(Grant No.51775537)Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.Y202084)。
文摘Current-carrying sliding is widely applied in aerospace equipment,but it is limited by the poor lubricity of the present materials and the unclear tribological mechanism.This study demonstrated the potential of MoS_(2)-based materials with excellent lubricity as space sliding electrical contact materials by doping Ti to improve its conductivity.The tribological behavior of MoS_(2)-Ti films under current-carrying sliding in vacuum was studied by establishing a simulation evaluating device.Moreover,the noncurrent-carrying sliding and static current-carrying experiments in vacuum were carried out for comparison to understand the tribological mechanism.In addition to mechanical wear,the current-induced arc erosion and thermal effect take important roles in accelerating the wear.Arc erosion is caused by the accumulation of electric charge,which is related to the conductivity of the film.While the current-thermal effect softens the film,causing strong adhesive wear,and good conductivity and the large contact area are beneficial for minimizing the thermal effect.So the moderate hardness and good conductivity of MoS_(2)-Ti film contribute to its excellent current-carrying tribological behavior in vacuum,showing a significant advantage compared with the traditional ones.
