A method based on Center Pattern Generator for quadruped leg control

In traditional strategy based on Center Pattern Generator (CPG), stance phases and swing phases are always fixed and their durations equal to each other approximately. Few CPG models care about the control of the knee joints under quadrupeds. In view of these deficiencies, this paper presents a model which is used to generate trajectories both for hips and for knees. The model has two desirable properties relative to the conventions. First, the knee joints are integrated with the hip joints into the CPG model. Then, a selector can adjust the duration of the stance phases and of the swing phases. Further more, the idea of the selector isn´t confined to a specific neural oscillator or an explicit model. Experiments demonstrate that the model is effective for legged robots control and its ratio of phases can be varied flexibly.