Model-based mechanical design of a passive lower-limb exoskeleton for assisting workers in shotcrete projection

Despite the current industrial trend towards automation, many workers are still daily exposed to heavy loads during their duties. Regarding the construction industry, the shotcrete projection results in a particularly arduous whole-body effort for the so-called “concrete reinforcement workers”. In this paper, the design of a passive robotic human assistance tool to assist workers in dealing with the specific task of shotcrete projection will be described. If the design of an effective aid plays a crucial role in improving the job’s quality, following the guidelines given by the French company Eiffage Infrastructures; besides, the acceptance of the proposed solution shall have special consideration. Therefore, starting from an in-site assessment of the scenario, the presented solution has been profoundly adjusted to address the issues coming from this particular task. The exoskeleton adaptability to different lower-limb activities has been preserved without lowering its comfort during daily life in the working area. The developed solution’s operation range has been specifically optimized to assist the worker during specific efforts without hindering the other movements.