Energy efficient walking with central pattern generators: From passive dynamic walking to biologically inspired control

Energy efficient walking with central pattern generators: From passive dynamic walking to biologically inspired control

Verdaasdonk, B.W.
Koopman, H.F.J.M.
Van der Helm, F.C.T.

Mechanical, Maritime and Materials Engineering

Biomechanical Engineering

2009-06-06

Like human walking, passive dynamic walking—i.e. walking down a slope with no actuation except gravity—is energy efficient by exploiting the natural dynamics. In the animal world, neural oscillators termed central pattern generators (CPGs) provide the basic rhythm for muscular activity in locomotion. We present a CPG model, which automatically tunes into the resonance frequency of the passive dynamics of a bipedal walker, i.e. the CPG model exhibits resonance tuning behavior. Each leg is coupled to its own CPG, controlling the hip moment of force. Resonance tuning above the endogenous frequency of the CPG—i.e. the CPG’s eigenfrequency—is achieved by feedback of both limb angles to their corresponding CPG, while integration of the limb angles provides resonance tuning at and below the endogenous frequency of the CPG. Feedback of the angular velocity of both limbs to their corresponding CPG compensates for the time delay in the loop coupling each limb to its CPG. The resonance tuning behavior of the CPG model allows the gait velocity to be controlled by a single parameter, while retaining the energy efficiency of passive dynamic walking.

Legged locomotion
Central pattern generator
Resonance tuning
Energy efficiency
Passive dynamic walking
Route to chaos

http://resolver.tudelft.nl/uuid:8f607e6a-a432-4421-8d51-52e554380049

Springer

1432-0770

Biological Cybernetics, 101 (1)

Institutional Repository

journal article

(c) 2009 The Authors