A modular, time-independent, path-based controller for assist- as- needed rehabilitative exoskeletons

After a traumatic event (e.g., orthopedic or neu-rological injury), engaging in activities of daily living (ADLs) encourages the individual and aids in relearning functional motions for the impaired limb. The outcome of robot-assisted rehabilitation is inherently connected to the control strategy adopted in the training sessions. Here, the authors propose a time-independent path-tracking controller with impedance modulation that provides assistance and guidance along the path. Based on the assist-as-needed (AAN) paradigm, a task-space-based force field controller was designed to cooperatively support the individual during training. The authors will illus-trate the flexibility of the proposed control strategy, showcasing its adaptability to various exoskeletons with minimal or minor adjustments. Leveraging the control versatility, the authors propose the application of this methods to two case studies: Float upper limb and TWIN lower limb exoskeletons.