Bifurcations and chaos in passive dynamic walking: A review

Irrespective of achieving certain success in comprehending Passive Dynamic Walking (PDW) phenomena from a viewpoint of the chaotic dynamics and bifurcation scenarios, a lot of questions still need to be answered. This paper provides an overview of the previous literature on the chaotic behavior of passive dynamic biped robots. A review of a broad spectrum of chaotic phenomena found in PDW in the past is presented for better understanding of the chaos detection and controlling methods. This paper also indicates that the bulk of literature on PDW robots is focused on locomotion on slope, but there is a thriving trend towards bipedal walking in more challenging environments.