A Power-Based Load Decoupling Method for Wearable Assistive Systems

Exoskeletons and exosuits are worn devices that are designed to support the human wearers ergonomically, reduce strain during physically demanding tasks (e.g., walking, lifting objects). Since the human is physically coupled to the mechanical system, safety is crucial for such a system. However, this aspect is often overlooked regarding load release, especially if unplanned. Therefore, this work investigates the utilization of a control strategy for the sudden unloading of a carried object for a force-controlled elbow effort-compensation device. The presented load release strategy observes the energy flow associated with the load compensation and enforces a strict limit on it. Additionally, the presented control strategy is experimentally validated and compared to the current state-of-art approach for different weights and release angles. The results highlight the potential of power-based load release mechanisms for force-controller effort-compensation devices.