Modelling, Control and Applications of Soft Pneumatic Actuators in Upper-Limb Exoskeletons: A Systematic Review

Abstract

Assistance and rehabilitation exoskeletons with soft robotic actuators are possible substitutes for the ones with rigid mechanical structures that might compromise the therapy process due to heavy weight, joint misalignment and discomfort. Modelling and controlling soft actuators, however, are challenging tasks due to the non-linearities inherent to properties of the materials used, such as silicone rubber and fabric, as well as the different possible geometries, the interaction with the human body and possible disturbances. A systematic review was performed to analyze and synthesize the state-of-the-art of recent designs and developments of upper limb exoskeletons with soft pneumatic actuators. The selected works were classified into two groups, of hand and wrist exoskeletons, and elbow and shoulder exoskeletons. A brief description of each work reviewed is presented alongside a discussion about the modelling and control strategies implemented, with the aim to contribute as a reference to future works on soft exoskeletons and assistive devices.