Powertrain selection for a biologically-inspired miniature quadruped robot

Transmission and actuator selection are crucial for robot locomotion at any scale. This is especially true at small scales where actuation choices are limited and locomotion is energetically expensive. These components control the payload capacity and determine the height of the obstacles the robot can navigate over. In this study, we analyze the drivetrain of the new Harvard Ambulatory MicroRobot (HAMR-V) to improve its walking performance. We modeled several transmission and actuator design concepts and investigated their force and displacement outputs. The results led to the selection of improved actuator and transmission designs. Using these new insights, we constructed a miniature quadruped with a payload capacity of 63% of its weight that can be used for on-board electronics for sensing, control, and power.