title: Suspending loads decreases load stability but may slightly improve body stability.
abstract: Here, we seek to determine how compliantly suspended loads could affect the dynamic stability of legged locomotion. We theoretically model the dynamic stability of a human carrying a load using a coupled spring-mass-damper model and an actuated spring-loaded inverted pendulum model, as these models have demonstrated the ability to correctly predict other aspects of locomotion with a load in prior work, such as body forces and energetic cost. We report that minimizing the load suspension natural frequency and damping ratio significantly reduces the stability of the load mass but may slightly improve the body stability of locomotion when compared to a rigidly attached load. These results imply that a highly-compliant load suspension could help stabilize body motion during human, animal, or robot load carriage, but at the cost of a more awkward (less stable) load.
authors.affiliation: School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, United States.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Ackerman
authors.affiliation: School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, United States.
authors.forename: Karna
authors.initials: K
authors.lastname: Potwar
authors.affiliation: School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, United States. Electronic address: ackermaj@purdue.edu.
authors.forename: Justin
authors.initials: J
authors.lastname: Seipel
mesh_terms: D001696:Biomechanical Phenomena; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D008954:Models, Biological; D016474:Weight-Bearing / Q000502:physiology*
keywords: Backpack suspension; Load carriage; Locomotion; Running; Stability; Vibration isolation