Numerical and experimental evaluation of the dynamic performance of kinematically redundant parallel manipulators

Fontes, João Vitor de Carvalho; Santos, João Cavalcanti; Silva, Maíra Martins da

doi:10.1007/s40430-018-1072-1

Cited by 14 publications

(12 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Without losing the generality, the proposed method also can be used in the similar PM-KRs, such as PRRR þ 2RRR, 2PRRR þ RRR and 3PRRR redundant parallel mechanisms. 57 Take the PRRR þ 2RRR redundant parallel mechanism as an example, the actuator P can be selected as a redundant parameter. And then, the proposed method can used to such parallel mechanism by adjusting the selected redundant parameter.…”

Section: Discussionmentioning

confidence: 99%

Singularity analysis and avoidance of a planar parallel mechanism with kinematic redundancy under a fixed orientation

Guo

2020

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

In this paper, the singularity of a planar mechanism with kinematic redundancy is studied. First, the architecture of the mechanism and the concept schematic diagram for singularity avoidance are stated. Next, inverse kinematics model of the planar parallel mechanism with kinematic redundancy is established. For determining the unique inverse solution of the mechanism under certain initial installation configuration, a comparison analysis based on the strategy tree and the virtual prototype is performed. Then, based on the obtained Jacobian matrices and the singular condition, the workspace-singularity map and two singular configurations of the mechanism are drawn. Finally, with the obtained workspace-singularity map, a singularity-free transition layer and an aisle can be found to perform to singularity avoidance, even if the initial designed trajectory passing through the second kind of singularity. Three tasks are carried out to illustrate that the workspace boundary and singular configuration can be changed by adjusting the kinematic redundant actuated parameter.

show abstract

Section: Discussionmentioning

confidence: 99%

Singularity analysis and avoidance of a planar parallel mechanism with kinematic redundancy under a fixed orientation

Guo

2020

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

show abstract

“…For a predefined trajectory X d , a set of desired positions for the active redundant joints δ d can be derived by one of the redundancy resolution schemes (Eqs. (19) or (20)). The desired positions of the active nonredundant joints θ d can be derived by using the IKM, described in Section 2.3, for given values of X d and δ d .…”

Section: Control Strategiesmentioning

confidence: 99%

“…Global approaches, also known as tracking problems, are usually employed to derive optimal inputs for a given trajectory of the manipulator's end-effector. Several global approaches have been used for solving redundancy resolution problems in the field of parallel manipulators: heuristic-based iterative methods [19], predictive approaches [16,20], dynamic programming [21], quadratic programming [22], topological analysis [23], among others. Nevertheless, the control of this kind of manipulator can be a challenging task.…”

Section: Introductionmentioning

confidence: 99%

Model-based joint and task space control strategies for a kinematically redundant parallel manipulator

et al. 2021

Self Cite

View full text Add to dashboard Cite

One alternative to overcome the presence of singularities within Parallel Manipulators’ workspace is kinematic redundancy. This design alternative can be realized by adding an extra active joint to a kinematic chain. Due to this addition, the IKM presents an infinite number of solutions requiring a redundancy resolution scheme. Moreover, Parallel Manipulators’ control may require complex strategies due to their coupled and complex dynamic and kinematic relations. In this work, a model-free, a joint space computed torque, and a hybrid joint-task-space computed torque control strategies are experimentally compared for a kinematically redundant parallel manipulator. The latter is a novel strategy that requires the measurement of the end-effector’s pose, which is performed by an eye-to-hand limited frame rate camera. The impact of up to three kinematic redundancy levels is also experimentally evaluated using prepositioning and ongoing positioning redundancy resolution schemes. The data are assessed by evaluating a prescribed trajectory executed using a planar kinematically redundant parallel manipulator. These results indicate that kinematic redundancy can not only be used as an alternative design for reducing the presence of singular regions, as claimed in the literature, but also be used along with model-based control strategies for improving dynamic performance and accuracy of parallel manipulators.

show abstract

“…Dividing the radius R in Eq. (20) into m equal parts, let Δ 1 = R/m and divide the inscribed angle 2π into n equal parts; let Δ 2 = 2π/n and all points in the searched space be reached through double loops, in which, the outer loop variable is j = 1, 2, …, m and the inner loop variable is k = 1, 2, 3, …, n.…”

Section: Displaying Program For the Constant-orientation Workpace Anmentioning

confidence: 99%

“…Then, considering redundant parallel manipulators, the literature [19] investigated the optimum design of 2-DOF redundant parallel manipulators and the evaluation of the dynamic performance [20,21].…”

Section: Introductionmentioning

confidence: 99%

Small-angle perturbation method for moving platform orientation to avoid singularity of asymmetrical 3-RRR planner parallel manipulator

Yin

Chen

Gao

et al. 2019

J Braz. Soc. Mech. Sci. Eng.

View full text Add to dashboard Cite

To overcome the weakness of the present methods of singularity avoidance for 3-RRR planar parallel manipulator (PPM), a new method of avoiding singular points on planed paths in workspace via orientation perturbation to moving platforms is proposed. First, an inverse kinematics model of 3-RRR PPM is built. A discriminant matrix of type II singularity is specified and the mapping between determinant values of the matrix and points in workspace of 3-RRR PPM is defined as a singularity surface. Then, the planned path is regarded as a directrix and intersecting line between cylindrical surfaces (its generating line is parallel to the z-axis) and the singularity surface is defined as a singularity curve corresponding to a planned path. By determining the critical perturbation value of the moving platform's orientation angle, the maximum value of the singularity curve corresponding to the planned path is no larger than 0 or its minimum value is no smaller than 0. Therefore, singular points on the planned path are avoided by changing the moving platform's orientation angle without changing the planned path. Moreover, a numerical realization method is given; example and experiment verification indicates that singular points in the planned path can be avoided when perturbation to the moving platform's orientation angle is no larger than 0.1745 rad. Therefore, the proposed method lays a solid foundation for singularity-free kinematics control based on inverse solutions.

show abstract

Numerical and experimental evaluation of the dynamic performance of kinematically redundant parallel manipulators

Cited by 14 publications

References 30 publications

Singularity analysis and avoidance of a planar parallel mechanism with kinematic redundancy under a fixed orientation

Singularity analysis and avoidance of a planar parallel mechanism with kinematic redundancy under a fixed orientation

Model-based joint and task space control strategies for a kinematically redundant parallel manipulator

Small-angle perturbation method for moving platform orientation to avoid singularity of asymmetrical 3-RRR planner parallel manipulator

Contact Info

Product

Resources

About