Analysis on an Origami-structured Actuator that Enhances Both Backdriveability and Power Amplification

In the author’s previous study, an origami-structured compliant actuator, named OSCA, was invented for human-robot interaction where sufficient moment output is required under a limited power supply. In this study, the compressibility of airflow within the actuator that essentially provides elasticity as well as backdriveability is in the spotlight. Elasticity can increase the actuator’s power output in the same way as does a series elastic actuator (SEA). This study demonstrates that an OSCA operated with a servo valve is equivalent to an SEA with a typical spring. That is, power output amplification can be achieved with congruent stiffness of the air within the actuator.