MR-3 Mini is a compact palletizing robot from Modena Robotics — a small, focused platform built around the same parallelogram-linkage layout used by full-size industrial palletizers, scaled down for lighter payloads and smaller footprints.
The mechanism
Four actuated joints give the arm its four degrees of freedom: a base rotation, a
shoulder, and two joints that together drive a parallelogram linkage running alongside the
main arm. That linkage is what keeps the wrist (and whatever tool is mounted on it) level
through the arm’s full range of motion without needing a dedicated wrist actuator — the
same trick classic industrial palletizers use. The URDF encodes this with eight <mimic>
joints driving the linkage’s own visual geometry in lockstep with the two real joints they
track; none of them are independent axes, so the actuated total is four, not the twelve a
naive joint count would suggest.
A caveat worth knowing: this URDF carries no mass or inertia data at all. ARMOR estimates mass for links missing it, so the arm still simulates, but the real, vendor-measured values aren’t available here the way they are for some other entries in this gallery.
About this file — read before importing
This links directly to mr3_mini_description, Modena Robotics’ own repository. ARMOR links directly to that repository rather than re-hosting anything, so what you get is exactly what Modena Robotics publishes, unmodified.