1 research outputs found
Safe physical HRI: Toward a unified treatment of speed and separation monitoring together with power and force limiting
So-called collaborative robots are a current trend in industrial robotics.
However, they still face many problems in practical application such as reduced
speed to ascertain their collaborativeness. The standards prescribe two
regimes: (i) speed and separation monitoring and (ii) power and force limiting,
where the former requires reliable estimation of distances between the robot
and human body parts and the latter imposes constraints on the energy absorbed
during collisions prior to robot stopping. Following the standards, we deploy
the two collaborative regimes in a single application and study the performance
in a mock collaborative task under the individual regimes, including
transitions between them. Additionally, we compare the performance under
"safety zone monitoring" with keypoint pair-wise separation distance assessment
relying on an RGB-D sensor and skeleton extraction algorithm to track human
body parts in the workspace. Best performance has been achieved in the
following setting: robot operates at full speed until a distance threshold
between any robot and human body part is crossed; then, reduced robot speed per
power and force limiting is triggered. Robot is halted only when the operator's
head crosses a predefined distance from selected robot parts. We demonstrate
our methodology on a setup combining a KUKA LBR iiwa robot, Intel RealSense
RGB-D sensor and OpenPose for human pose estimation.Comment: 8 pages, 6 figure