An optimized workspace calculation method is proposed for parallel stabilized platform testing systems.This method refines the searched space progressively in order to approach the boundary of the workspace from both ...An optimized workspace calculation method is proposed for parallel stabilized platform testing systems.This method refines the searched space progressively in order to approach the boundary of the workspace from both the inside and the outside of it.The orientation density is defined and used as an evaluation index to calculate the orientation workspace.The algorithm of the orientation density is embedded into the computer program of the workspace calculation.Then the workspaces of the testing system are solved.In the solution,the orientation density is regarded as a discrete function of the reachable workspace.As a result,the reachable workspace and the orientation workspace are represented in the same multidimensional graphs.Finally the useful workspace of the testing system is determined based on these results.This case study indicates that the calculation efficiency is enhanced by adopting the optimized method and the practicability of workspace study is improved by proposing the orientation density.展开更多
For the existing problems of walking chair robot such as simple function,lower bearing capacity and not walking in complex environment,a novel varistructured quadruped / biped human-carrying walking chair robot is pro...For the existing problems of walking chair robot such as simple function,lower bearing capacity and not walking in complex environment,a novel varistructured quadruped / biped human-carrying walking chair robot is proposed.The proposed robot could be used as biped and quadruped walking chair robots.Considering the conversion of the walking chair robot from the quadruped to the biped or vice versa,6-UPS and 2-UPS＋UP（U,P and S are universal joint,the prismatic pair,and sphere joint,respectively） parallel mechanisms are selected as the leg mechanism of the biped walking robot and quadruped walking robot,respectively.Combining the screw theory and theory of mechanism,the degrees of freedom of the leg mechanism and the body mechanism in diferent motion states are computed so as to meet the requirements of mechanism design.The motion characteristics of the 2-UPS＋UP parallel mechanism which is the key part of the walking chair robot are analyzed.Then,the workspace of the moving platform is drawn and the efect of the structural parameters on the workspace volume is studied.Finally,it is found that the volume of the workspace of the moving platform is bigger when the side length ratio and the vertex angle ratio of the fxed platform and the moving platform which are isosceles triangles are close to 1.This study provides a theoretical foundation for the prototype development.展开更多
基金Supported by the Ministerial Level Advanced Research Foundation (870102056)
文摘An optimized workspace calculation method is proposed for parallel stabilized platform testing systems.This method refines the searched space progressively in order to approach the boundary of the workspace from both the inside and the outside of it.The orientation density is defined and used as an evaluation index to calculate the orientation workspace.The algorithm of the orientation density is embedded into the computer program of the workspace calculation.Then the workspaces of the testing system are solved.In the solution,the orientation density is regarded as a discrete function of the reachable workspace.As a result,the reachable workspace and the orientation workspace are represented in the same multidimensional graphs.Finally the useful workspace of the testing system is determined based on these results.This case study indicates that the calculation efficiency is enhanced by adopting the optimized method and the practicability of workspace study is improved by proposing the orientation density.
基金supported by National Natural Science Foundation of China (No. 61075099) FP7-PEOPLE-2012-IRSES:Marie Curie Action "International Research Staf Exchange Scheme" (No. 318902)
文摘For the existing problems of walking chair robot such as simple function,lower bearing capacity and not walking in complex environment,a novel varistructured quadruped / biped human-carrying walking chair robot is proposed.The proposed robot could be used as biped and quadruped walking chair robots.Considering the conversion of the walking chair robot from the quadruped to the biped or vice versa,6-UPS and 2-UPS＋UP（U,P and S are universal joint,the prismatic pair,and sphere joint,respectively） parallel mechanisms are selected as the leg mechanism of the biped walking robot and quadruped walking robot,respectively.Combining the screw theory and theory of mechanism,the degrees of freedom of the leg mechanism and the body mechanism in diferent motion states are computed so as to meet the requirements of mechanism design.The motion characteristics of the 2-UPS＋UP parallel mechanism which is the key part of the walking chair robot are analyzed.Then,the workspace of the moving platform is drawn and the efect of the structural parameters on the workspace volume is studied.Finally,it is found that the volume of the workspace of the moving platform is bigger when the side length ratio and the vertex angle ratio of the fxed platform and the moving platform which are isosceles triangles are close to 1.This study provides a theoretical foundation for the prototype development.
