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...

This chapter focuses on the mobility analysis of spatial parallel manipulators. It first develops an analytical methodology to investigate the instantaneous degree of freedom (DOF) of the end-effector of a parallel manipulator. And then, the instantaneous controllability of the end-effector is discussed from the viewpoint of the possible actuation schemes which will be especially useful for the...

In this paper, a systematic methodology for enumeration of the kinematic structures of parallel manipulators is presented. Parallel manipulators are classified into planar, spherical, and spatial mechanisms. The classification is followed by an enumeration of the kinematic structures according to the degrees of freedom and connectivity listing. In particular, a class of parallel manipulators wi...

In this paper we study the dynamics and kinematics of manipulators that have fewer actuators than degrees of freedom. These under{actuated manipulators arise in a number of important applications such as free{ ying space robots, hyper{redundant manipulators, manipulators with structural exibility, etc. In our analysis we decompose such under{actuated manipulators into component active and passi...

In this paper, the static balancing of existing spatial and planar parallel manipulators by the addition of balancing elements is addressed. Static balancing is defined here as the set of conditions on manipulator dimensional and inertial parameters which, when satisfied, ensure that the weight of the links does not produce any force (or torque) at the actuators for any configuration of the man...

Various performance indices are used for the design of serial manipulators. One method of optimization relies on the condition number of the Jacobian matrix. The minimization of the condition number leads, under certain conditions, to isotropic configurations, for which the roundoff-error amplification is lowest. In this paper, the isotropy conditions, introduced elsewhere, are the motivation b...

In engineering applications, the singularity, and the forward and inverse displacement of spatial parallel manipulators have received a great deal of attention. This paper presents a new simple but effective methodology to investigate these problems based on the analysis of the degree of freedom (DoF) of the spatial parallel manipulator. Through numerical method, the singularity and the forward...

Various performance indices are used for the design of serial manipulators. One method of optimization relies on the condition number of the Jacobian matrix. The minimization of the condition number leads, under certain conditions, to isotropic configurations, for which the roundoff-error amplification is lowest. In this paper, the isotropy conditions, introduced elsewhere, are the motivation b...

In this paper, we study the isotropic design of two types of spatial parallel manipulators: a three-degrees-of-freedom manipulator and the Stewart–Gough platform. The isotropic conditions for Jacobian matrices, which relate the input joint velocity and output Cartesian velocity, are determined separately using a pure symbolic method. Thereafter, upon determining the isotropic conditions for bot...