Adaptive Human-Robot Interaction Control of the Lower Extremity Robotic Exoskeleton with Magnetorheological Actuators*

In this paper, a lower extremity robotic exoskeleton is presented to provide paralytic patients with rehabilitation training in two modes including robot-active mode and human-active mode. Magnetorheological (MR) actuators are designed and set in the robot to provide flexible joint torque. In the robot-active mode, the MR actuator works to transfer torque to the robotic joint, limiting the output torque to protect the patients from secondary injury and reducing the power consumption. While in the human-active mode, the MR actuator generates controllable damping torque by changing its input current to provide anti-resistance training to help patients strengthen muscles. Then, an adaptive human-robot interaction control method is proposed to realize smooth and stable transition between these two modes. The effect of the MR actuators is also taken into consideration. Experiments are conducted to verify performance of the robotic control.