Position-based kinematics for 7-DoF serial manipulators with global configuration control, joint limit and singularity avoidance

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Faria, C (Author) Other; Ferreira, F (Author) Other; Erlhagen, W (Author) Other; Monteiro, S (Author) Other; Bicho, E (Author) Other

Journal

Title: Mechanism and Machine Theory

Vol. 121

Pages: 317-334

ISSN: 0094-114X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 48 Citations

Scopus - 64 Citations

Other information

Authenticus ID: P-00N-6ME

DOI: 10.1016/j.mechmachtheory.2017.10.025

Abstract (EN): This paper presents a novel analytic method to uniquely solve inverse kinematics of 7 degrees-of-freedom manipulators while avoiding joint limits and singularities. Two auxiliary parameters are introduced to deal with the self-motion manifolds: the global configuration (GC), which specifies the branch of inverse kinematics solutions; and the arm angle (psi) that parametrizes the elbow redundancy within the specified branch. The relations between the joint angles and the arm angle are derived, in order to map the joint limits and singularities to arm angle values. Then, intervals of feasible arm angles for the specified target pose and global configuration are determined, taking joint limits and singularities into account. A simple metric is proposed to compute the elbow position according to the feasible intervals. When the arm angle is determined, the joint angles can be uniquely calculated from the position-based inverse kinematics algorithm. The presented method does not exhibit the disadvantages inherent to the use of the Jacobian matrix and can be implemented in real-time control systems. This novel algorithm is the first position-based inverse kinematics algorithm to solve both global and local manifolds, using a redundancy resolution strategy to avoid singularities and joint limits.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 18