Obstacle Avoidance for Collaborative Robots Using Modulation Dynamical Systems Technique

Abstract

Collaborative robots (cobots) operating in shared human-robot workspaces require reactive, computationally lightweight obstacle avoidance to guarantee both safety and task continuity. This paper presents a simulation-based study of obstacle avoidance for the 6-DOF UR3 cobot (Universal Robots) using Modulation Dynamical System approach (MDS). A nominal autonomous dynamical systems (DS) with a stable target attractor is first designed to generate goal-directed endeffector motion. Reactive collision avoidance is then achieved by locally modulating the nominal velocity field through a modulation matrix constructed from each obstacle's geometric representation, deflecting the flow around obstacles while preserving asymptotic convergence to the attractor and avoiding the need for global path re-planning. The framework is evaluated in simulation across scenarios containing single and multiple static obstacles, where the cobot consistently reaches the target along collision-free trajectories. Limitations of the approach are analyzed and discussed, motivating directions for future work.