Compact Variable Transmission

Overview

Robots must be both fast and strong, but a fixed gear ratio forces a trade-off between speed and torque. We develop compact variable transmission mechanisms (VTM) that dynamically adjust the torque–speed ratio inside the actuator itself.

Our implementations span twisted-string-based automatic transmissions, actively variable four-bar linkage CVTs with controllable stiffness, and their applications to robotic fingers, hands, and legs for highly dynamic tasks.