title: Periodic spring-mass running over uneven terrain through feedforward control of landing conditions.
abstract: This work pursues a feedforward control algorithm for high-speed legged locomotion over uneven terrain. Being able to rapidly negotiate uneven terrain without visual or a priori information about the terrain will allow legged systems to be used in time-critical applications and alongside fast-moving humans or vehicles. The algorithm is shown here implemented on a spring-loaded inverted pendulum model in simulation, and can be configured to approach fixed running height over uneven terrain or self-stable terrain following. Offline search identifies unique landing conditions that achieve a desired apex height with a constant stride period over varying ground levels. Because the time between the apex and touchdown events is directly related to ground height, the landing conditions can be computed in real time as continuous functions of this falling time. Enforcing a constant stride period reduces the need for inertial sensing of the apex event, which is nontrivial for physical systems, and allows for clocked feedfoward control of the swing leg.
authors.affiliation: Department of Computer Science and Engineering, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Luther R
authors.initials: LR
authors.lastname: Palmer
authors.forename: Caitrin E
authors.initials: CE
authors.lastname: Eaton
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D003198:Computer Simulation; D005121:Extremities / Q000502:physiology*; D025461:Feedback, Physiological / Q000502:physiology; D005684:Gait / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D009991:Oscillometry / Q000379:methods; D005082:Physical Exertion / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D016138:Walking / Q000502:physiology*