TABLE OF CONTENTS In this Section the application of the guidelines outlined in the previous Section is illustrated with the help of an example. In the case of animal walking the locomotion pattern is called gait. Even if more general definitions can be given, in the following only periodic gaits will be taken into account. The characteristics of a locomotion gait can be defined through the concepts of cycle time, duty factor and phase lag [Waldron and Song (1989)].
The cycle time is the time required for a leg to complete a locomotion cycle.
The duty factor df i is the time fraction of a cycle time in which the leg i is in the power stroke phase.
The phase lag ? i is the fraction of a cycle period by which the beginning of the return stroke of leg i lags behind the beginning of the return stroke of the left front leg, chosen as a reference.
Alternatively, instead of considering the phase lags between each pair of legs, some authors [Pfeiffer et. al. (1995)] make use of phase lags between ipsilateral and contralateral legs.
As an example a hexapod gait that following [Golubtisky et. at. (1998)] we call caterpillar gait is taken into account to illustrate the steps in the design of the corresponding CPG. In this pattern of locomotion the right and left legs move in synchrony: first...
