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
This is a very timely review of body armour materials and systems since new test standards are currently being written, or reviewed, and new, innovative products released. Of greatest importance, however, is the recen...This is a very timely review of body armour materials and systems since new test standards are currently being written, or reviewed, and new, innovative products released. Of greatest importance, however, is the recent evolution, and maturity, of the Ultra High Molecular Weight Polyethylene fibres enabling a completely new style of system to evolve e a stackable system of Hard Armour Plates. The science of body armour materials is quickly reviewed with emphasis upon current understanding of relevant energy-absorbing mechanisms in fibres, fabrics, polymeric laminates and ceramics. The trend in ongoing developments in ballistic fibres is then reviewed, analysed and future projections offered. Weaknesses in some of the ceramic grades are highlighted as is the value of using cladding materials to improve the robustness, and multi-strike performance, of Hard Armour Plates. Finally, with the drive for lighter, and therefore smaller, soft armour systems for military personnel the challenges for armour designers are reported, and the importance of the relative size of the Hard Armour Plate to the Soft Armour Insert is strongly emphasised.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.
文摘This is a very timely review of body armour materials and systems since new test standards are currently being written, or reviewed, and new, innovative products released. Of greatest importance, however, is the recent evolution, and maturity, of the Ultra High Molecular Weight Polyethylene fibres enabling a completely new style of system to evolve e a stackable system of Hard Armour Plates. The science of body armour materials is quickly reviewed with emphasis upon current understanding of relevant energy-absorbing mechanisms in fibres, fabrics, polymeric laminates and ceramics. The trend in ongoing developments in ballistic fibres is then reviewed, analysed and future projections offered. Weaknesses in some of the ceramic grades are highlighted as is the value of using cladding materials to improve the robustness, and multi-strike performance, of Hard Armour Plates. Finally, with the drive for lighter, and therefore smaller, soft armour systems for military personnel the challenges for armour designers are reported, and the importance of the relative size of the Hard Armour Plate to the Soft Armour Insert is strongly emphasised.
