Antagonistic torsion spiral springs variable stiffness actuator - ATOSS VSA

Abstract

This paper presents the design and construction of an unprecedented, controllable stiffness, elastic series actuator, using two flat spiral torsion springs. This actuator has some advantages compared to elastic series actuators with fixedspring rigidity, which either have little rigidity, and end up deforming undesirably, or have a lot of rigidity and end up damaging themselves and the environment around them. The proposed solution aims to maintain the functionality of protecting the robot and its surroundings, absorbing any unexpected impact that may happen during this interaction. Compliance, combined with intelligent control systems capable of dealing with dynamic environments, has the potential of allowing the development of more versatile robots, as compliant actuators can be under-actuated and embedded computer systems tend to increase in capacity and reduce in cost. The research goes from computer-aided mechanical design, mathematical modeling of a spring and design of components that fit certain force and size constraints, to testing a new actuator under different working conditions. At the end of the research, the first prototype of the actuator with manual stiffness control was built.