  Inspired by biological motion generation, central pattern generators (CPGs)
is frequently employed in legged robot locomotion control to produce natural
gait pattern with low-dimensional control signals. However, the limited
adaptability and stability over complex terrains hinder its application. To
address this issue, this paper proposes a terrain-adaptive locomotion control
method that incorporates deep reinforcement learning (DRL) framework into CPG,
where the CPG model is responsible for the generation of synchronized signals,
providing basic locomotion gait, while DRL is integrated to enhance the
adaptability of robot towards uneven terrains by adjusting the parameters of
CPG mapping functions. The experiments conducted on the hexapod robot in Isaac
Gym simulation environment demonstrated the superiority of the proposed method
in terrain-adaptability, convergence rate and reward design complexity.
