Figure 9.

Real-time data of energy-efficient and adaptable locomotion on three different terrains. (A) The output of the online terrain classification system which is a preprocessed visual sensory signal. (B) The modulatory input MI of the CPG which is directly controlled by the sensory signal. It was set to 0.04 (fast wave gait), then 0.06 (tetrapod gait), and finally 0.19 (fast tripod gait). (C) The positive (o_S) and negative (o_E) accumulated errors (Figures 7A,B). They control leg adaptation to deal with different terrains. (D–F) The TC-, CTr-, and FTi-joint angles of the right middle leg (R2) during walking from fine gravel (loose terrain) to gravel (rough terrain) to floor (hard terrain). They represent the leg movement including adaptation. (G) Gait diagram showing the different energy-efficient gaits of AMOS II while traversing the terrains. Black boxes indicate swing phase while white areas between them indicate stance phase. Abbreviations are referred to Figure 1. Above pictures show snap shots from the camera on AMOS II used for the terrain classification while walking. Below pictures show snap shots of locomotion of AMOS II during the experiment. Note that one time step is ≈ 0.037 s.