This paper presents a geometrical representation of robot grasping and a definition of "relative form closure" of point contact restraint based on the concepts of positive linear combination,affine combinati...This paper presents a geometrical representation of robot grasping and a definition of "relative form closure" of point contact restraint based on the concepts of positive linear combination,affine combination,convex combination,etc.in the screw space.The dual equivalence theorem,topological equivalence theorem and algebraic equivalence theorem are derived from the defined restraint cone and freedom cone in the dual screw spaces.A J0-function method of computer-aided grasp planning is implemented more efficiently than other proposed methods.The states of restraint and instantaneous motion of a rigid body grasped by a set of point contacts are specified by the unisense degrees of freedom and unisense degrees of restraint.Finally,a quality measure of robot grasping is provided for the synthesis procedure of relatively form-closed grasp.展开更多
传统的规范形理论常用于研究弱非线性振动问题,对于非线性项不再是小量的强非线性振动系统则并不适用。为进一步拓展这一理论的适用范围,基于研究单自由度强非线振动问题的待定瞬时固有频率法,提出了可用来求解两自由度强非线性振动系...传统的规范形理论常用于研究弱非线性振动问题,对于非线性项不再是小量的强非线性振动系统则并不适用。为进一步拓展这一理论的适用范围,基于研究单自由度强非线振动问题的待定瞬时固有频率法,提出了可用来求解两自由度强非线性振动系统的改进规范形方法。首先引入了复数形式的一阶方程并且利用新的未知瞬态基频替换系统原有的固有频率,再依照规范形理论计算了一类两自由度强非线性Du ffing-V an der Po l振子的5阶传统规范形。最后求解平均方程获得了此类系统的瞬时频率、振幅以及相应的稳态渐近解。通过对比算例中本文方法、原有规范形理论及数值仿真的结果,证明了改进的规范形理论对于多自由度强非线性振动问题的适用性。展开更多
基金Project supported by the National Natural Science Foundation of ChinaDoctor's Research Foundation of State Education Commission
文摘This paper presents a geometrical representation of robot grasping and a definition of "relative form closure" of point contact restraint based on the concepts of positive linear combination,affine combination,convex combination,etc.in the screw space.The dual equivalence theorem,topological equivalence theorem and algebraic equivalence theorem are derived from the defined restraint cone and freedom cone in the dual screw spaces.A J0-function method of computer-aided grasp planning is implemented more efficiently than other proposed methods.The states of restraint and instantaneous motion of a rigid body grasped by a set of point contacts are specified by the unisense degrees of freedom and unisense degrees of restraint.Finally,a quality measure of robot grasping is provided for the synthesis procedure of relatively form-closed grasp.
文摘传统的规范形理论常用于研究弱非线性振动问题,对于非线性项不再是小量的强非线性振动系统则并不适用。为进一步拓展这一理论的适用范围,基于研究单自由度强非线振动问题的待定瞬时固有频率法,提出了可用来求解两自由度强非线性振动系统的改进规范形方法。首先引入了复数形式的一阶方程并且利用新的未知瞬态基频替换系统原有的固有频率,再依照规范形理论计算了一类两自由度强非线性Du ffing-V an der Po l振子的5阶传统规范形。最后求解平均方程获得了此类系统的瞬时频率、振幅以及相应的稳态渐近解。通过对比算例中本文方法、原有规范形理论及数值仿真的结果,证明了改进的规范形理论对于多自由度强非线性振动问题的适用性。