Synthesis and Analysis of a Group of 3-Degree-of-Freedom Partially Decoupled Parallel Manipulators

Abstract

The kinematics decoupling for parallel manipulators is studied in this paper. Based on the topological structure characteristics of parallel mechanisms, the internal relationship between kinematics decoupling and basic kinematics chains is revealed, and the basic principle for structural synthesis of topologically decoupled mechanisms is put forward. Using this theory, a group of 3 degree-of-freedom (DOF) partially decoupled manipulators are synthesized. The expected kinematic outputs of these manipulators are 1-DOF translation and 2-DOF rotation, and motions along or about undesired directions do not exist. The kinematics analysis of a newly synthesized manipulator is discussed and the results indicate that the decoupling property of these architectures makes possible reaching real time control and path planning of parallel manipulators.

Kinematic design of a family of 6-DOF partially decoupled parallel manipulators

“…Jin and Yang [12] classified the kinematic decoupling into two types, i.e. complete coupling (each independent output is controlled by only one input) and partial decoupling (neither complete decoupling nor complete coupling).…”

“…There are quite few methods for synthesizing the DPMs systematically, although several methods are studied for the un-decoupled PMs, such as constraint synthesis approach [14,15,16] based on screw theory, and Lie sub-group approach [17,18] based on the algebraic properties of a Lie group of the Euclidean displacement set. Jin and Yang [12] proposed a methodology for synthesizing DPMs based on constitution of basic kinematic chains, which is suitable for DPMs with less DOFs other than six DOFs because of the hard construction of basic kinematic chains with too many DOFs. In this paper, a systematic approach for type synthesis of 3-limb symmetrical 3P3S DPMs is introduced as follows.…”

A new isotropic and decoupled 6-DoF parallel manipulator

“…According to [24,[27][28][29], a set of six coordinates S =[s 1 s 2 s 3 s 4 s 5 s 6 ] T is able to define the manipulator in a specific task may be chosen to represent the position P of the TCP (tool center point) and the orientation A of the end-effector with suitable conventions. A similar concept is adopted in [30].…”

Effects of constraint errors on parallel manipulators with decoupled motion

“…Hence, motion planning and control of the end-effector of PMs become very complicate. In order to cope with the motion coupling problem, researchers have studied some parallel manipulators with decoupled motion structures [1][2][3][4][5][6][7][8].…”