In parallel manipulator design, usual 6-DOF PMs, like the Stewart platform, suffer from the disadvantages of difficult forward kinematics, coupled motion, and small workspace, so that the motion planing and control become very complicated and difficult to be implemented in real application. Most of the PMs with lower mobility are over-constrained when assembly errors are considered [1]. Therefo...

This paper proposes a new family of spatial 3-DOF (degree of freedom) parallel manipulators with two translational and one rotational DOFs. The manipulators in this family are the variations of the parallel manipulators, which are capable of very high rotational capability, introduced by X.-J. Liu, J. Wang, and G. Pritschow (“A new family of spatial 3-DoF fully parallel manipulators with high r...

Robotica / FirstView Article / July 2015, pp 1 14 DOI: 10.1017/S0263574715000557, Published online: 10 July 2015 Link to this article: http://journals.cambridge.org/abstract_S0263574715000557 How to cite this article: Yi Lu, Nijia Ye and Ling Ding Type synthesis of spatial 3-DoF parallel mechanisms with planar sub-chains using revised digital topological graphs and arrays. Robotica, Available o...

The kinematics of a two rotational degrees-of-freedom (DOF) spherical parallel manipulator (SPM) is developed based on the coordinate transformation approach and the cosine rule of a trihedral angle. The angular displacement, angular velocity, and angular acceleration between the actuators and end-effector are thus determined. Moreover, the dynamic model of the 2-DOF SPM is established by using...

In this paper, a simple and convenient method – Recursive Matrix method – is proposed for kinematic and dynamic analysis of all types of complex manipulators. After addressing the principle of the method, an example – a 3-DOF parallel manipulator with prismatic actuators – is demonstrated for the efficiency of the method in solving kinematic and dynamic problems of complex manipulators. With th...

This paper addresses the workspace analysis of two 3-DOF translational parallel mechanisms designed for machining applications. The two machines features three fixed linear joints. The joint axes of the first machine are orthogonal whereas these of the second are parallel. In both cases, the mobile platform moves in the Cartesian x−y−z space with fixed orientation. The workspace analysis is con...

A spherical parallel manipulator (also called an orientational parallel manipulator or rotational parallel manipulator) refers to a threedegree-of-freedom (3-DoF) parallel manipulator in which the moving platform undergoes a 3-DoF spherical motion or rotates about a fixed point. In this paper, we propose a new method for the type synthesis of non-overconstrained (isostatic) spherical parallel m...

In this paper we consider the dynamic modelling of compliant micropositioning mechanisms using flexure hinges. A simple modelling method is presented that is particularly useful for modelling parallel micropositioning mechanisms. This method is based upon linearisation of the geometric constraint equations of the compliant mechanism. This results in a linear kinematic model, a constant Jacobian...

Mechanism innovation design is an important topic in the field of robot. Many kinds of limbs with specific degrees of freedom (DOFs) are proposed, in which a new joint, P-joint is introduced. In order to obtain new mechanisms of parallel manipulators (PMs), a principle for mechanism design of PMs is adopted, which is based on the special Plücker coordinates for describing a limb. By the princip...