Biomechatronic Analysis of Lower Limb Exoskeletons for Augmentation and Rehabilitation Applications

Lower limb exoskeletons are wearable robots worn by human operators for various purposes. Their design, control and biomechanical aspects have been discussed in many publications in the literature. However, there is a gap in their robotic nature analysis, and few documents discussed the biomechatronic aspect of the robotic devices. In this scenario, this paper presents a brief analysis of the biomechatronic system’s components of lower limb exoskeletons for augmentation and rehabilitation applications. In this case, the biomechatronic system is considered to have five components, which include: Mechanisms, Actuators, Sensors, Control, and Human–Robot Interaction. A literature review was initially conducted to explore documents with the highest relevance to the topic for analyses. Therefore, in Mechanisms: metabolic cost, biomechanics of walking, average human walking speed, mechanics of human movements, movements at the hip, at the knee and at the ankle joints are addressed. In Actuators, different types of actuators used by different projects from the literature such as electric motors, series electric actuators (SEAs), pneumatic, hydraulic, and pneumatic muscle actuators are analyzed. In Sensors and Control, different types of sensors and control strategies adopted by different projects are also analyzed. In Human–Robot Interaction, cognitive human–robot interaction and physical human–robot interaction are discussed. Finally, the work is concluded with some important considerations for this analysis.