The use of robotic manipulators in remote and sensitive areas calls for more robust solutions when handling joint failure, and the industry demands mathematically robust approaches to handle even the worst case scenarios. For both serial and parallel manipulators torque failure is indeed a worst case scenario. Thus, a systematic analysis of the effects of external forces on manipulators with pa...

This work studies in detail how the judicial application of compliance in parallel manipulators can produce manipulators that require significantly lower actuator effort within a range of desired operating conditions. We propose a framework that uses the Jacobian matrices of redundant parallel manipulators to consider the influence of compliance both in parallel with the actuated joints as well...

An architecturally singular parallel manipulator is a parallel manipulator with architectural singularities spanning the whole workspace. It should be abandoned in the design process. This paper deals with the generation of architecturally singular 6-SPS parallel manipulators with linearly related planar platforms. The forward displacement analysis of the 6-SPS parallel manipulator with linearl...

In this paper, 3-PPR planar parallel manipulators with ∆or U-shape base are compared with respect to their workspace size and kinematic sensitivity to joint clearances. First, the singularities and workspace of a general 3-PPR planar parallel manipulator are analyzed. Then, an error prediction model applicable to both serial and parallel manipulators is developed. As a result, two nonconvex qua...

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...

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...

Comparing with the serial ones, parallel manipulators have potential advantages in terms of high stiffness, accuracy and speed (Merlet, 2001). Especially the high accuracy and speed performances make the parallel manipulators widely applied to the following fields, like the pick-and-place operation in food, medicine, electronic industry and so on. At present, the key issues are the ways to meet...

this work intends to deal with the optimal kinematic synthesis problem of tricept parallel manipulator. observing that cuboid workspaces are desirable for most machines, we use the concept of effective inscribed cuboid workspace, which reflects requirements on the workspace shape, volume and quality, simultaneously. the effectiveness of a workspace is characterized by the dexterity of the manip...

Parallel manipulators have the advantage of high speed and high precision in the theory of mechanisms. This has opened up broad possibilities for the use of parallel manipulators in many fields. But in real applications, due to the inevitable manufacturing tolerances and assembling errors, the actual kinematic parameters of parallel manipulators are always unequal to the nominal values and cali...

This paper introduces a novel method for Cartesian trajectory and performance optimization control of kinematically-redundant truss-based manipulators (TBMs): The Virtual Serial Manipulator Approach. The approach is to model complex parallel-actuated TBMs as simpler kinematically-equivalent virtual serial manipulators. Standard control methods for kinematicallyredundant serial manipulators can ...