Local Velocity Field Control of a Nonholonomic Base for Kinesthetic Interaction with a Collaborative Arm

This paper introduces a local control framework for mobile manipulators that enables coordinated motion be- tween a nonholonomic base and a robotic arm without relying on any sensors mounted on the platform. The method is based on velocity vector fields defined in the mobile base frame and uses only internal joint measurements from the manipulator. A reduced kinematic model provides the translational end-effector (TEE) position, which drives all base motion decisions. By evaluating distance- and angle-based thresholds, the controller generates smooth linear and angular velocity commands that guide the base through extension, alignment, and retreat behav- iors. The system supports real-time human interaction, such as kinesthetic guidance across the full reachable workspace, while respecting the nonholonomic constraints of the platform. Since the base controller is independent of the arm’s control strategy, it is compatible with autonomous planning, teleoperation, or demonstration-based teaching. The proposed control strategy is particularly suited for collaborative scenarios where intuitive human guidance is essential and reliance on global localization is unnecessary. Experimental results with physical kinesthetic guidance demonstrate the platform’s ability to reactively follow end-effector motion, preserving reachability and manipulability across the full workspace.