Nanometer Precision With a Planar Parallel Continuum Robot

In many cases, soft and continuum robots represent an interesting alternative to articulated robots because they have the advantages of miniaturization capability, safer interactions with humans and often simpler fabricating and integration. However, these benefits are usually considered to arise at the expense of accuracy and precision because of the soft or flexible limbs. This paper demonstrates that, with a proper design, a planar parallel continuum robot is capable of great precision. Indeed, the proposed 3-Degrees-of-Freedom planar parallel continuum robot exhibits a precision of 9.13 nm in position and 1.2 μrad in orientation. In addition, the novel robotic design leverages the effect of the actuators' defects, making the robot more precise than its own actuators. Finally, the workspace of the proposed robot (62.3 mm$^2$, 0.6452 rad) is significantly larger than most compliant mechanisms, which is particularly interesting when both very high precision and relatively large displacements are required.