Dynamic simulation and experimental study of impedance control for robotic orthosis to assist the overhead operations in the shipbuilding process

In this study, dynamic simulations of impedance control were performed for a robotic orthosis, which can assist the overhead operations in the shipbuilding industry, and hardware experiments were conducted to validate the simulation results. The robotic orthosis that was designed for the simulations consisted of a 2-degree-of-freedom (DOF) shoulder, a 1-DOF elbow, and a 3-DOF wrist. The equations of motion of the robotic orthosis were constructed based on a relative coordinate formulation. The gravitational force, the contact force between the robotic orthosis and the human hand, and the control force were considered external forces. The impedance control algorithm was used to calculate the control force. A test hardware of the robotic orthosis was designed and constructed for the experiments for the validation of the simulation results. For simplicity, only 3-DOF motions were considered in the experiments. The experiment results were compared with the simulation results. The results show that the impedance control algorithm is appropriate for controlling the robotic orthosis for the overhead operations in the shipbuilding process.