Model-Based Real-Time Simulator for Robotic Electromagnetic Actuation

We present a real-time model-based simulator-in-the-loop control for a robotic electromagnetic actuator (EMA) in this letter. We first formulate a simplified magnetic field model applicable to a real-time simulator by using the Biot–Savart law and a mathematical approximation. Subsequently, we embedded this model in a real-time simulator developed in the ROS Gazebo environment. The simulator can compute the magnetic field at a point in under 5 ms with a 5.14% difference in the magnetic fields in the region of interest (30mm cube) compared to the finite-element model simulation. For the principal axis, the error from the actual measured value was less than 4%. To achieve simulator-in-the-loop control, we input the computed input current corresponding to each coil from the simulator to the real system. The dynamic motion of a magnetic capsule and a magnetic guidewire in the simulator is validated by comparing the real system response with that of the simulator. The experimental results show that the simulator exhibits a similar motion to that of the real system. Finally, the simulator-in-the-loop control demonstrates the synchronous movement of the capsule with 1–5° errors while conducting pitching angle feedback control, and magnetic guidewire control with 2.29 mm accuracy.