Passive dynamic walkers (PDWs) can walk down shallow slopes with no motors or feedback controllers, using gravity as their only source of power input into the system. These systems have been used to examine the stability of human locomotion. The orbital stability of these systems under “ideal” conditions has been well established (Goswami 1997). However, like humans, these PDWs can fall over if...

A human walker vaults up and over each stance limb like an inverted pendulum. This similarity suggests that the vertical motion of a walker's center of mass reduces metabolic cost by providing a mechanism for pendulum-like mechanical energy exchange. Alternatively, some researchers have hypothesized that minimizing vertical movements of the center of mass during walking minimizes the metabolic ...

Most of the existing control schemes for walking bipeds are based on the so-called zero-moment point (ZMP) stability condition. Such schemes have three common characteristics: 1) bending at knees thus to avoid singular positions; 2) closed-loop controllers for trajectory tracking at the joints, 3) using higher power actuators, in particular at ankles, to compensate for the rotational motion (fa...

With free walk velocity; the individual will naturally enlist the speed that will provide maximum energy efficiency. Inspired by this idea, we exploit a passivity based control strategy to study, the preferred walking gait of a compass-like biped robot. In fact, for any ground slope, we use a dynamic optimization of the mechanical cost which is proportional to the mechanical work in the system ...

1 Motivation and State of the Art The compass-gait biped and simplest walking model [1,2] have been useful as tools that abstract away the details of a specific walker, allowing the study of properties of the passive nonlinear dynamics. Similarly, the two-link brachiator of Gomes and Ruina [3] has demonstrated that energy-efficient brachiation is possible, i.e., “walking under the surface” (Fig...

This work aims at finding optimal trajectory of compassgait biped walking robot in terms of energy consumption and passive dynamic walking. The planar biped model, an inverted double pendulum, has a free hinge at all joints, i.e., the hip and stance ankle. The impulsive external force is exerted on the swing ankle for short initial period. With the equation of motion, the power of external forc...

Passive stretching is widely used for individuals with spasticity in a belief that tightness or contracture of soft tissues can be corrected and lengthened. Evidence for the efficacy of passive stretching on individuals with spasticity is limited. The aim of this review was to evaluate the evidence on the effectiveness of passive stretching in children with spastic cerebral palsy. Seven studies...

Captain Basile is a robot inspired from the cockroach and built to participate at the SAE Walking Machine Challenge 2004, an undergraduate competition of walking robots. The robot weighs 35 kg and is 86 cm long, 58 cm wide and 38 cm tall. Initially validated by the use of dynamic simulations, this pneumatic actuated hexapod is characterised by specialized legs, passive visco-elastic elements an...

Applying an evolutionary algorithm, we first develop the morphology of a simulated passive dynamic bipedal walking device, able to walk down a shallow slope. Using the resulting morphology and adding minimal motor and sensory equipment, a neural controller is evolved, enabling the walking device to walk on a flat surface with minimal energy consumption. The applied evolutionary algorithm fixes ...

A class of biped locomotion called Passive Dynamic Walking (PDW) has been recognized to be efficient in energy consumption and a key to understand human walking. Although PDW is sensitive to the initial condition and disturbances, studies of Quasi-PDW which incorporates supplemental actuators have been reported to overcome this sensitivity. In this article, we propose a reinforcement learning m...