Type Synthesis of 2T1R Planar Parallel Mechanisms and Their Moduling Development Applications

Abstract

The two translational degrees-of-freedom (DOF) and one rotational DOF (2T1R) planar parallel mechanisms (PMs) have the characteristics of simple structures, simple kinematic and dynamic models, and ease of control and allow for a variety of application prospects. This paper concentrates on the derivations of the 5-DOF hybrid manipulators based on the synthesized mechanisms. To understand the effect of the constraint on the motion of a rigid body clearly, the method of reciprocal product between the wrench screw (constraint) and the twist screw (motion) is used and the relationships between the constraint and the motion of a rigid body are analyzed as well. The results are extended to the relationships between the limb constraint and the axes of limb joints. Then, limbs are divided into planar motion and spatial motion limbs in view of their motion characteristics, and some common limbs with constraint are listed. After that, based on the type synthesis method, a class of 2T1R planar PMs with common limbs is carried out. Meanwhile, some typical planar closed chains with two same limbs are obtained in the process of type synthesis. Finally, a 2T1R kinematically redundancy planar PM and two 2R1T spatial PMs are derived by making simple changes to the obtained mechanisms, and detailed derivations of three 5-DOF hybrid manipulators with the ability of processing spatial complex surface are given. Proved by the test parts, the accomplishment of deriving novel robot configurations with regard to expectant motion are quite valuable and practical.

Design and Kinematic Analysis of a Novel Planar Parallel Robot With Pure Translations

“…The rotary joint will not exist since it is required to be orthogonal with all three constraint couples (this geometric relationship doesn't exist in 3D space) based on the remaining expressions of ( 6). The parallelogram joint case has the same conditions as the prismatic joint because of the similar expressions between ( 5) and (7). Therefore, the feasible kinematic chains and parallel mechanism structures can be found on the basis of the above calculations.…”

“…It tends to have higher speed, acceleration, stiffness and payload capacity, lower inertia property, at the cost of limited reachable workspace and many singularity configurations, by comparison with its counterpart serial robot in the similar conditions [1,2]. Parallel manipulators have received increased interest due to their intrinsic advantages and are widely employed in various industrial applications: pick-and-place robots [3,4], flight simulators [5], multi-axis parallel kinematic machine tools [6,7], haptic devices [8] and medical robots [9]. A systematic design of a group of novel parallel architectures is the primary step in robotics.…”

A New 3-DOF 2T1R Parallel Mechanism: Topology Design and Kinematics

“…Studies on 3-DOF 2T1R PMs are relatively limited, but they have the potential for extensive use in devices for grasping, positioning, entertainment, and posture adjustment [1]. Zhang et al [7] designed a modular 2T1R planar PM, but did not provide kinematic analysis. Qu et al [8] proposed a decoupled PM synthesis method based on Lie group and screw theory, and obtained a new fully decoupled 2T1R PM in space and plane.…”

Type Synthesis of 5-DOF Hybrid (Parallel-Serial) Manipulators Designed from Open Kinematic Chains

“…The POC sets method, proposed above by Shen et al [34], was applied by the authors in paper [47]: the authors developed a novel 5-DOF hybrid manipulator with a 2-DOF serial part and a 3-DOF parallel part. Xu et al [48] applied screw theory techniques to design 5-DOF hybrid manipulators with 3-and 4-DOF parallel parts; later, in the works [49][50][51], the authors synthesize planar and spatial 3-DOF parallel mechanisms within various 5-DOF hybrid manipulators. Xie et al [24] performed a research similar to [49] and considered type synthesis of 3-DOF 1T2R parallel mechanisms, which represented a parallel part of other 5-DOF hybrid manipulators.…”