Kinematic analysis of a planar manipulator with anti-parallelogram joints and offsets

Philippe Wenger (1) , Matthieu Furet

1 LS2N - Laboratoire des Sciences du Numérique de Nantes

Industrial robotic manipulators mostly use revolute or pris-matic joints. In this paper, an anti-parallelogram mechanism, referred to as X-joint, is considered as an alternative choice to a revolute joint in the kinematic design of robots. This choice lends itself well to a remote actuation with cables, which contributes to lower inertia. We show that replacing revolute joints with X-joints in a planar 2-dof manipula-tor improves drastically the size of the workspace in the presence of joint limits. On the other hand, the kinematic analysis becomes significantly more difficult, owing to the much more complicated algebra involved in the input/output equations. The inverse kinematics, the singularities and the workspace optimization are investigated. A tentative design of a 2-X planar linkage is proposed and compared to its 2-R counterpart.

Mots clés: Anti-parallelogram joint; Inverse Kinematics; Singularity; Workspace; Optimal Design

Domaines: Automatique / Robotique; Génie mécanique [physics.class-ph]

Philippe Wenger, Matthieu Furet. Kinematic analysis of a planar manipulator with anti-parallelogram joints and offsets. Advances in Robot Kinematics, Springer, 2020. ⟨hal-03010542⟩