Robotics: Science and Systems XVI
Reachable Sets for Safe, Real-Time Manipulator Trajectory Design
Patrick Holmes, Shreyas Kousik, Bohao Zhang, Daphna Raz, Corina Barbalata, Matthew Johnson Roberson, Ram VasudevanAbstract:
For robotic arms to operate in arbitrary environments, especially near people, it is critical to certify the safety of their motion planning algorithms. However, there is often a trade-off between safety and real-time performance; one can either carefully design safe plans, or rapidly generate potentially-unsafe plans. This work presents a receding-horizon, real-time trajectory planner with safety guarantees, called ARMTD (Autonomous Reachability-based Manipulator Trajectory Design). The method first computes (offline) a reachable set of parameterized trajectories for each joint of an arm. Each trajectory includes a fail-safe maneuver (braking to a stop). At runtime, in each receding-horizon planning iteration, ARMTD constructs a parameterized reachable set of the full arm in workspace and intersects it with obstacles to generate sub-differentiable, provably-conservative collision-avoidance constraints on the trajectory parameters. ARMTD then performs trajectory optimization over the parameters, subject to these constraints. On a 6 degree-of-freedom arm, ARMTD outperforms CHOMP in simulation, never crashes, and completes a variety of real-time planning tasks on hardware.
Bibtex:
@INPROCEEDINGS{Holmes-RSS-20, AUTHOR = {Patrick Holmes AND Shreyas Kousik AND Bohao Zhang AND Daphna Raz AND Corina Barbalata AND Matthew Johnson Roberson AND Ram Vasudevan}, TITLE = {{ Reachable Sets for Safe, Real-Time Manipulator Trajectory Design}}, BOOKTITLE = {Proceedings of Robotics: Science and Systems}, YEAR = {2020}, ADDRESS = {Corvalis, Oregon, USA}, MONTH = {July}, DOI = {10.15607/RSS.2020.XVI.100} }