Comparative study of actuators in biomechatronic projects of exoskeletons and human-machine interfaces

Abstract

According to data from the World Health Organization and The Brazilian Institute of Geography and Statistics, it is evident that a large number of people face some type of disability, besides the growing aging of the world population. Increasingly, rehabilitation and assistive technologies will be needed to help these people have a better quality of life. Therefore, investments in the development and improvement of technologies such as exoskeletons and robotic limbs are essential. Some of the crucial points for actuators in exoskeletons with built-in reduction are volume, weight, and reduction capacity. For example, a large volume would impair mobility when passing through doors, and a high inertial mass in a lower limb exoskeleton would alter the gait pattern or consume a lot of energy, reducing battery life. That is why actuators with harmonic or cycloidal reductions are used, but they have high costs. With the frequent advancement of additive manufacturing technologies, there is the possibility of 3D printing on polymer in these types of reducers. Another option to eliminate the inertial mass is to place the actuators attached to the upper body and transmit the power by cables or straps. This project aims to develop a bench and experimental protocols for testing five types of actuators in biomechatronics: metallic and 3D printed harmonic; metallic and 3D printed cycloidal, and remote geared motors with power transmitted by Bowden cable. (AU)