In this paper, a model of translation gateway is proposed. The communications between IPv4 network and IPv6 network are realized by using the Microsoft intermediate driver technology in environment of Windows 2000.
Extensively studied since the early nineties,cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes.In particular,underconstra...Extensively studied since the early nineties,cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes.In particular,underconstrained and planar cable robots can find application in several fields,and specifically,in the packaging industry.The planning of dynamically feasible trajectories(i.e.,trajectories along which cable slackness and excessive tensions are avoided) is particularly challenging when dealing with such a topology of cable robots,which rely on gravity to maintain their cables in tension.This paper,after stressing the current relevance of cable robots,presents an extension and a generalization of a model-based method developed to translate typical cable tension bilateral bounds into intuitive limits on the velocity and acceleration of the robot end effector along a prescribed path.Such a new formulation of the method is based on a parametric expression of cable tensions.The computed kinematic limits can then be incorporated into any trajectory planning algorithm.The method is developed with reference to a hybrid multi-body cable robot topology which can be functionally advantageous but worsen the problem of keeping feasible tensions in the cables both in static and dynamic conditions.The definition of statically feasible workspace is also introduced to identify the positions where static equilibrium can be maintained with feasible tensions.Finally,some aspects related to the practical implementation of the method are discussed.展开更多
This paper presents the idea of constructing reconfigurable limbs by integrating metamorphic linkages as subchains.The planar five-bar metamorphic linkages that have three phases resulting from locking of motors are c...This paper presents the idea of constructing reconfigurable limbs by integrating metamorphic linkages as subchains.The planar five-bar metamorphic linkages that have three phases resulting from locking of motors are considered.Under the assumption that the constraint exerted by the reconfigurable limb can switch between no constraint,a constraint force,and a constraint couple,the output motions of the metamorphic linkage in its two planar four-bar linkage phases are identified.By adding an appropriate joint to planar four-bar linkages with translational output,four planar five-bar linkages that can be employed in the construction of reconfigurable limbs are enumerated.Serial chains that can provide a constraint couple and a constraint force are synthesized based on screw theory.Reconfigurable limbs that have three configurations associated with the three distinct phases of the metamorphic linkages are assembled with planar five-bar metamorphic linkages and serial chains with four degrees of freedom.A class of reconfigurable parallel mechanisms are constructed by connecting a moving platform and a base with three identical reconfigurable limbs.The degrees of freedom of the reconfigurable parallel mechanism in different configurations with the metamorphic linkages in different phases are given.Finally,the actuation scheme for this kind of mechanisms is addressed.展开更多
基金Supported by the Natural Science Foundation of Henan Province(0511011400) Supported by the Natural Science Foundation of Education Department of Henan Province(2004520014)
文摘In this paper, a model of translation gateway is proposed. The communications between IPv4 network and IPv6 network are realized by using the Microsoft intermediate driver technology in environment of Windows 2000.
基金supported by the Universita degli Studi di Padova under Grant No.CPDA088355/08
文摘Extensively studied since the early nineties,cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes.In particular,underconstrained and planar cable robots can find application in several fields,and specifically,in the packaging industry.The planning of dynamically feasible trajectories(i.e.,trajectories along which cable slackness and excessive tensions are avoided) is particularly challenging when dealing with such a topology of cable robots,which rely on gravity to maintain their cables in tension.This paper,after stressing the current relevance of cable robots,presents an extension and a generalization of a model-based method developed to translate typical cable tension bilateral bounds into intuitive limits on the velocity and acceleration of the robot end effector along a prescribed path.Such a new formulation of the method is based on a parametric expression of cable tensions.The computed kinematic limits can then be incorporated into any trajectory planning algorithm.The method is developed with reference to a hybrid multi-body cable robot topology which can be functionally advantageous but worsen the problem of keeping feasible tensions in the cables both in static and dynamic conditions.The definition of statically feasible workspace is also introduced to identify the positions where static equilibrium can be maintained with feasible tensions.Finally,some aspects related to the practical implementation of the method are discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.51075025,51175029)Beijing Natural Science Foundation of China(Grant No.3132019)the Program for New Century Excellent Talents in University of China(Grant No.NCET-12-0769)
文摘This paper presents the idea of constructing reconfigurable limbs by integrating metamorphic linkages as subchains.The planar five-bar metamorphic linkages that have three phases resulting from locking of motors are considered.Under the assumption that the constraint exerted by the reconfigurable limb can switch between no constraint,a constraint force,and a constraint couple,the output motions of the metamorphic linkage in its two planar four-bar linkage phases are identified.By adding an appropriate joint to planar four-bar linkages with translational output,four planar five-bar linkages that can be employed in the construction of reconfigurable limbs are enumerated.Serial chains that can provide a constraint couple and a constraint force are synthesized based on screw theory.Reconfigurable limbs that have three configurations associated with the three distinct phases of the metamorphic linkages are assembled with planar five-bar metamorphic linkages and serial chains with four degrees of freedom.A class of reconfigurable parallel mechanisms are constructed by connecting a moving platform and a base with three identical reconfigurable limbs.The degrees of freedom of the reconfigurable parallel mechanism in different configurations with the metamorphic linkages in different phases are given.Finally,the actuation scheme for this kind of mechanisms is addressed.
