The development of energy efficient actuation represents one of the biggest challenges in robotics research today. This letter presents the generalisation of design and control concepts for a recently introduced asymmetric compliant actuator, as well as its extension to multi-DoF articulated robotic systems. The actuator design consists of two actuation branches with significantly different stiffness and energy storage capacity properties driving a single joint. The letter studies and presents a novel method to select the design parameters of asymmetric compliant actuation schemes to improve the energy efficiency of multi-DoF articulated robots powered by this type of actuators. An optimisation problem is formulated to optimise the actuation parameters for energy efficient operation. Simulation studies performed on a 2-DoF leg as proof-of-concept demonstrate significant improvements in electrical energy efficiency and reduction in peak torque and electrical power requirements. Furthermore, biarticulated actuation arrangements are also investigated, and they are proven to further enhance the energy efficiency of the robotic leg.
- Compliant Joint/Mechanism
- Force Control