Adaptive Oscillator-Based Control for Soft Exosuit

Rapid and real-time adaptive gait phase recognition is a key requirement for wearable robots to provide accurate assistance in the real world. Firstly, this study develops a high-level controller based on an adaptive oscillator using only an inertial measurement unit (IMU) worn on the lower leg. The adaptive oscillator is driven by angular velocity alone; concurrently, a walking state recognizer is developed to estimate gait features further. Then, in the low-level control system, considering the influence of unknown dynamics, feedforward compensation for ankle joint angle and suit–human stiffness is added. To validate the proposed method, an experimental study has been performed with four healthy subjects. The results demonstrate that the adaptive oscillator and state recognizer can rapidly and accurately estimate the gait phase and identify state transitions in real time, and the assistive force reduces the level of muscle activation. Finally, the proposed method highlights the potential for rehabilitation and mobility beyond the lab setting.