Cooperative path completion using a modular magnetically levitated planar actuator and a 4-DOF robotic arm

Magnetically levitated planar actuators (MLPAs) offer contactless motion, high precision, and kinematic flexibility, making them promising positioning platforms for industrial manufacturing applications such as laser cutting, visual inspection, additive manufacturing, and painting; however, their integration in cooperative tasks with robot manipulators remains largely unexplored. This study proposes a cooperative framework in which a disc-magnet mover and a 4-DOF robotic arm execute a configuration-sampled, time-optimal planned path to complete a defined trajectory with orientation constraints. The proposed path planning algorithm utilizes a geometrically modeled arm inverse kinematics together with a filtered discrete arm workspace to generate a global search graph, whose states are represented by locally feasible configurations found via a Jacobian-based redundancy resolution. To validate the flexibility of the MLPA against conventional implementations, a trajectory-aligned mover baseline is developed, in which the mover is constrained to remain fixed during the interaction phase with the manipulator. Experimental validation on three types of trajectories with a real MLPA system showed promising results from the proposed cooperative path planner compared to the baseline, with a faster completion time of 5 2 . 8 2 ± 0 . 3 7 s against the baseline of 6 4 . 7 ± 0 . 2 6 s . The cooperative path planner states were successfully executed, obtaining a maximum positional tracking RMSE of 0.54 m m with a standard deviation of 0.43 m m and an attack angle RMSE of 0 . 1 8 ° , with a standard deviation of 0 . 0 9 ° for a line trajectory. The second trajectory confirmed the need for cooperative mover-arm operation to obtain a feasible interaction solution. The final sinusoidal trajectory showed the high dynamic tilting range achieved from the mover to enable the lower DOF arm to complete the proposed path, demonstrating the potential of MLPA-robotic arm integration for flexible manufacturing on kinematically limited industrial lines.