Micrometer Positioning Accuracy With a Planar Parallel Continuum Robot

Abstract

Parallel Continuum Robots (PCR) have several advantages over classical articulated robots, notably a large workspace, miniaturization capabilities and safe human-robot interactions. However, their low accuracy is still a serious drawback. Indeed, several conditions have to be met for PCR to reach a high accuracy, namely: a repeatable mechanical structure, a correct kinematic model, and a proper estimation of the model’s parameters. In this article, we propose a methodology that allows reaching a micrometer accuracy with a PCR. This approach emphasizes the importance of using a repeatable continuum mechanism, identifying the most influential parameters of an accurate kinematic model of the robot and precisely measuring them. The experimental results show that the proposed approach allows to reach an accuracy of 3.3 µm in position and 0.5 mrad in orientation over a 10 mm long circular path. These results push the current limits of PCR accuracy and make them good potential candidates for high accuracy automatic positioning tasks.

Singularity analysis of 3-DOF planar parallel continuum robots with constant curvature links

“…Lilge et al 10.3389/frobt.2022.1082185 One particularly interesting and widely used architecture in the realm of rigid parallel kinematic mechanisms (PKM) are planar 3-DOF manipulators, allowing the end-effector positioning and orientation in a plane (Bonev et al, 2003). Recent research has focused on creating similar mechanisms featuring continuum links (Moghadam et al, 2015;Lilge et al, 2020;Nuelle et al, 2020;Mauzé et al, 2021;Yan et al, 2021;Zaccaria et al, 2022), potentially enabling applications such as micro-positioning, fragile workpiece handling, human-robot collaboration or assembly tasks which are prone to jamming. In this paper, we are extending the current state of the art on planar PCR by further exploring the design space of such structures.…”

MiGriBot: A miniature parallel robot with integrated gripping for high-throughput micromanipulation

“…A possible way to enlarge the workspace is to make the links wholly deformable which leads to parallel continuum robots (13)(14)(15). However, developing accurate models for these classes of robots is complex and their inversion is time consuming leading to low frequency control loops (16)(17)(18)(19).…”