Kinematical and static force analysis on redundant drive wire mechanism with velocity constraint modules to reduce the number of actuators

Abstract

This study proposes new wire mechanism called "the redundant drive wire mechanism" (RDWM), driven by double actuator modules. The RDWM is configured with velocity constraint modules (VCMs) that provide high-acceleration global and fine local motions. Suitable RDWM candidates are found by combining the kinematic analysis with static force analysis. The study also clarifies the role of VCMs in reducing the required number of actuators while keeping the orientation of the top plate. We propose a judgment procedure with three steps: a static force analysis in the whole motion space, a kinematic analysis that finds the active constraint space wherein the top plate can produce velocity and a static force analysis in this active constraint space. The proposed judgment procedure and the role of VCMs are validated by examples.

Dynamically feasible motions of a class of purely-translational cable-suspended parallel robots

“…Since a general quadric in space can be expressed as p T e Qp e = 0 (25) where p e = [x, y, z, 1] T and Q is a 4 × 4 matrix with real coefficients, it can be proven that the quadric defined by det(A ) = 0 has…”

“…Translational CSPRs were also proposed for large-scale 3D printing [20], or to help people affected by motion disabilities to overcome architectural barriers [21]. Other authors presented overconstrained architectures for CDPRs still based on a parallelogram arrangement of cables, but with positive cable tensions being ensured by antagonistic additional cables [22][23][24][25] or antagonistic jacks [26][27][28][29].…”

“…This can be useful for robots that have to perform pickand-place operations over large workspaces, if the EE follows a point-to-point trajectory such as those presented in [5,7], where each target point is reached with zero velocity (but nonzero acceleration). Also, dynamic motions can be used to recover a robot in case of a cable breakdown [32]; if a robot with parallelogram actuation having more than 6 cables, for instance those presented in [17,[21][22][23][24][25], undergoes a sudden cable break, it could be brought back to its safe post-failure workspace by using dynamic trajectories such as those presented here for a 6-cable robot. Finally, cable robots can also be used for entertainment, as suggested in [33] where a robotic rollercoaser was proposed having a capsule driven by 3 cables for passengers to ride in; a translational parallel robot performing dynamical trajectories could provide a entertaining ride while avoiding rotational motions that could cause discomfort to passengers in some cases.…”

Erratum to: Kinematical and static force analysis on redundant drive wire mechanism with velocity constraint modules to reduce the number of actuators

“…Unfortunately, the original version of this article [1] contained an error. The acknowledgements section was included incorrectly.…”