Synchronization-based trajectory generation method for a robotic suit using neural oscillators for hip joint support in walking

A new synchronization-based trajectory generation method is proposed for a robotic suit that is designed to assist walking by supporting the hip joints. Neural oscillators are connected to each hip joint of the robotic suit to synchronize the suit’s movement with the human user’s movement (outer synchronization). At the same time, mutual inhibition is incorporated between the neural oscillators on the left and right hip joints of the suit to help maintain a human-gait-like anti-phase relationship (inner inhibition). We developed a two-degree-of-freedom robotic suit, which consists of two actuators located where the human hip joints are. Each actuator has a built-in torque sensor, which measures the mutual joint torque generated if any difference arises between the movement of a user and that of the suit. The mutual joint torque serves as input to neural oscillators, which control each actuator of the robotic suit through outer synchronization with the mutual joint torque and inner inhibition. The inhibitory weight, used to adjust the inhibitory strength between neural oscillators, is designed in a series of simulations. We conducted walking experiments to show the validity of our proposal for walking assistance of the robotic suit with mutual inhibition between neural oscillators.