Low-Cost Quadruped Leg Module: Design and Initial Validation

We present a new quadruped leg design focused on reducing part cost, reducing manufacturing complexity, and maximizing the use of regionally-available components. This study describes the simulations that allowed an iterative design process, the design itself and the initial testing results. The simulations represent simple leg scenarios such as running, jumping, accelerating, and standing up. With these tests, we are able to define leg requirements that shape the design process. This results in a 1kg-mass quadruped leg capable of producing 12.6 Nm of torque for short bursts thanks to its brushless motors and its 1:9 reduction. This design is then experimentally tested to verify its characteristics. This includes testing of servo motors, brushless motors, and motor-reduction systems. Of the latter, joint compliance, backlash, static and dynamic torque were tested. These are the first steps to develop a low-cost quadruped robot for autonomous locomotion research.