ACTIVE HIP ACTUATION FOR WALKING BIPED WITH PASSIVE OPTION

Abstract

Biped robots are desired as the ideal solution over wheel vehicles when traversing over rough terrain due to the simplicity and efficiency when mimicking the natural and dynamic motion of a human gait. The Intelligent Systems and Automation Laboratory (ISAL) at the University of Kansas designed and built a three legged 2D biped walking robot to establish a testbed for future testing. This paper focuses on the development and testing of a novel hip joint that allows actuation with the ability to remain passive. This study was completed concurrently with the development of a full robot as part of other projects. The biped robot, known as the Jaywalker, is comprised of two main actuation systems: the Hybrid Parallel Ankle Actuator (HPAA) and the Hip Ratchet System (HRS). This study focused on the design and testing of the HRS which achieves hip actuation through the use of a locking mechanism integrated into each hip joint that couples the legs to a shared drive system. The ability to lock and unlock the hip joint through the HRS enables the Jaywalker to function in passive or actuated states at the hips. Testing of the HRS was conducted in both passive and actuated states on the Jaywalker testbed. Testing of the hip provided proof in the concept of using a single drive in combination with a ratchet mechanism to actuate the hip while providing a passive option. The HRS also provided the capability to vary step lengths future testing that requires turning, rough terrain, and stair climbing.