In this study, the static stability of the grasp of a single planar object is analyzed using the potential energy method. In previous papers, we considered cases in which individual fingers were replaced by a multidim...In this study, the static stability of the grasp of a single planar object is analyzed using the potential energy method. In previous papers, we considered cases in which individual fingers were replaced by a multidimensional translational spring model, in which each finger is constructed with prismatic joints. Human hands and the most developed mechanical hands are constructed with revolute joints. In this paper, the effects of fingertip rotation and a revolute joint spring model are investigated. A grasp stiffness matrix is analytically derived by considering not only frictional rolling contact but also frictionless sliding contact. The difl＇erence between the frictional stiffness matrix and the frictionless one is analytically obtained. The effect of local curvature at contact points is analytically derived. The grasp displacement directions affected by the change in curvature and the contact condition are also obtained. The derived stiffness matrix of the revolute joint model is compared with that of the prismatic joint model, and then the stiffness relation is clarified. The gravity effect of the object is also considered. The effectiveness of our method is demonstrated through numerical examples. The stability is evaluated by the eigenvalues of the grasp stiffness matrix, and the grasp displacement direction is obtained by the corresponding eigenvectors. The effect of joint angle is also discussed.展开更多
In this paper we propose a COncurrent Production Engineering System （COPES） for the flexible transfer line （FTL） layout design in a restricted area. COPES first determines the buffer size in front of the bay of ea...In this paper we propose a COncurrent Production Engineering System （COPES） for the flexible transfer line （FTL） layout design in a restricted area. COPES first determines the buffer size in front of the bay of each machine tool in the FTL and then initializes a computer aided design （CAD） system to draw the FTL in a restricted area. We develop a set of modules systems which have been integrated into a single framework, in accordance with the practice of concurrent engineering. Concurrent engineering involves the cooperation of these activities. It＇s expected that the developed COPES can improve the cooperation between production engineers＇ and the plant designer. This can be done by enabling the production engineers＇ to make better decision regarding FTL buffer size.展开更多
文摘In this study, the static stability of the grasp of a single planar object is analyzed using the potential energy method. In previous papers, we considered cases in which individual fingers were replaced by a multidimensional translational spring model, in which each finger is constructed with prismatic joints. Human hands and the most developed mechanical hands are constructed with revolute joints. In this paper, the effects of fingertip rotation and a revolute joint spring model are investigated. A grasp stiffness matrix is analytically derived by considering not only frictional rolling contact but also frictionless sliding contact. The difl＇erence between the frictional stiffness matrix and the frictionless one is analytically obtained. The effect of local curvature at contact points is analytically derived. The grasp displacement directions affected by the change in curvature and the contact condition are also obtained. The derived stiffness matrix of the revolute joint model is compared with that of the prismatic joint model, and then the stiffness relation is clarified. The gravity effect of the object is also considered. The effectiveness of our method is demonstrated through numerical examples. The stability is evaluated by the eigenvalues of the grasp stiffness matrix, and the grasp displacement direction is obtained by the corresponding eigenvectors. The effect of joint angle is also discussed.
文摘In this paper we propose a COncurrent Production Engineering System （COPES） for the flexible transfer line （FTL） layout design in a restricted area. COPES first determines the buffer size in front of the bay of each machine tool in the FTL and then initializes a computer aided design （CAD） system to draw the FTL in a restricted area. We develop a set of modules systems which have been integrated into a single framework, in accordance with the practice of concurrent engineering. Concurrent engineering involves the cooperation of these activities. It＇s expected that the developed COPES can improve the cooperation between production engineers＇ and the plant designer. This can be done by enabling the production engineers＇ to make better decision regarding FTL buffer size.
