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Applications of mechanical systems and technology
Published in Alan Darbyshire, Charles Gibson, Mechanical Engineering, 2023
Alan Darbyshire, Charles Gibson
A mechanism may be defined as a kinematic chain in which one element is fixed for the purpose of transmitting or transforming motion. A kinematic chain is made up of several linked elements. Two elements which are linked together constitute a kinematic pair. If they are hinged, they are called a turning pair. If one element is constrained to slide through or around another, they are called a sliding pair. If one element rotates inside another in a screw thread, they are called a screwed pair.
Structural synthesis of the new type 4DOF robot manipulators for industry and medicine
Published in Australian Journal of Mechanical Engineering, 2023
Assume that each of the designed robot manipulators is composed of kinematic pairs consisting of the same number and the same elements on each. In this case, a cylindrical kinematic pair () consisting of different combinations of a single DOF revolute joint () and prismatic joint () for each leg, as well as a single passive DOF in platform-type robot manipulators is placed. Thus, using expression (3), we can determine the total number of kinematic pairs in the robot manipulator with . We can also determine the number of kinematic pairs () placed on each leg of the robot manipulator and the number of total constraints of the end effectors in the subspace using the (4) expressions.
Elastodynamic analysis of multibody systems and parametric mass matrix derivation
Published in Mechanics Based Design of Structures and Machines, 2022
Ali Raoofian, Afshin Taghvaeipour, Ali Kamali E.
Equation (18) is not in minimal form since the existing generalized coordinates are dependent to each other. However, by introducing constraint equations (14) and (15) into Eq. (18), the dependent coordinates vanish. A parallel manipulator with nin independent EVAs, and DoF in passive kinematic pairs, will have generalized coordinates. The n × n mass matrix M of a parallel manipulator is then obtained by taking the Hessian of the total kinetic energy Ttot with respect to the generalized independent EVA i.e., in which, is the ith independent EVA. Also, if the parallel manipulator consists of np passive kinematic pairs and the ith kinematic pair applies constraints (), then is defined as,
Design and static analysis of new deployable mechanisms based on the four-bar slider–crank mechanism
Published in Mechanics Based Design of Structures and Machines, 2022
Jianwei Sun, Song Gao, Wenrui Liu, Fanchen Kong, Xiaodong Li
M is the DOF of the mechanism, d is the order of the mechanism, n is the number of components of the mechanism, g is the number of kinematic pairs, is the DOF of the kinematic pair number i, and v is the redundant constraints of the mechanism. For the deployable mast unit in Figure 10, d = 3, n = 10ne+3, g = 18ne, fi=18ne, v = 6ne−5 and that