Authors: Xiao Rong Zhu, Hui Ping Shen, Wei Zhu
Abstract: This paper addresses geometry design and operating mode optimum design of a new kind of 2-DOF parallel manipulator actuated horizontally by linear actuators. The forward and inverse kinematics of this manipulator are derived. The four groups of inverse solution correspond to four different operating modes which cannot transit to each other smoothly. The workspace and the singularity trajectory of each mode are discussed. Based on the desired workspace, the geometry of the mechanism is determined. The operating mode of the mechanism is optimized according to distributing of all global and local performance indices on the workspace. The results are very useful for the design and application of the new manipulator with multiple forward and inverse solutions.
1843
Authors: Guang Hua Wu, Lie Hang Gong, Xin Wei Ji, Zhong Jun Wu, Yong Jun Gai
Abstract: The methodology of the optimal design for the 6-UPU parallel mechanism (PM) is presented based on genetic algorithms. The optimal index which expressed by Jacobian matrix of the PM is first deduced. An optimal model is established, in which the kinematic dexterity of a parallel mechanism is considered as the objective function. The design space, the limiting length of the electric actuators and the limit angles of universal joints are taken as constraints. The real-encoding genetic algorithm is applied to the optimal design of a parallel mechanism, which is proved the validity and advantage for the optimal design of a similar mechanism.
1055
Authors: Yan Wei Zhang, Bin Wei, Guo Hua Cui, Nan Wang
Abstract: This study focus on the stiffness analysis of a three-DOF orientation fine-tuning manipulator for segment assembly robots in shield tunneling machines. In underground space development, shield tunneling machines are widely used in subway tunnels, channel tunnels and other kinds of tunnels. As one of the key sub-devices in a shield tunneling machine, a segment assembly robot is used to automatically form the segment lining. In order to evaluate the operational capacity, an analysis of the inverse kinematics is conducted. The local performance atlas, including stiffness and dexterity, are investigated. The results show that the proposed orientation fine-tuning manipulator has good performances and it can meet the needs.
904
Authors: Hong Jian Yu, Bing Li, Yang Wang, Ying Hu
Abstract: In this paper a novel 4 Degree-of-Freedom (DOF) parallel mechanism with the configuration of 4PUS-1RPU is applied for a 5-axis Hybrid Kinematic Machine (HKM), combined with an additional linear motion. The Parallel Kinematic Mechanism (PKM) is composed of four symmetrical driving chains and one central passive sub-chain. Firstly, the mechanism is described, and the mobility is analyzed. Then the inverse kinematics of the 4-DOF PKM and the direct kinematics for the serial central sub-chain are then presented. The dexterity and the workspace analysis for the mechanism are also carried out. Finally, machining experiment research is presented to verify the effect of the prototype. The research provides the basis for the further parametric design with consideration of kinematic and dexterity performance.
420
Authors: Liang Zhang, Zhen Lin Jin
Abstract: The kinematic transmission property and distributions in workspace of a novel spherical 3-RRR parallel mechanism are given. The orthogonal layout feature of the parallel mechanism is described. The equations for inverse displacement and kinematic transmission property are derived by the relation of geometry. The kinematic transmission evaluation index of a spherical 3-RRR parallel mechanism is defined. Finally, the distribution of the index in workspace was given, which can provide theoretical basis for the application of the spherical mechanism.
3513