Fig.1

Experimental model of quadruped robot"

Fig.2

Coordinate systems in the gait planning"

Fig.3

Gait event of quadruped robot walking with static gait"

Fig.4

Schematics diagram of walkingcycle of quadruped robot"

Fig.5

Schematics diagram of motion planning of robot"

Fig.6

Rectangular plantar trajectory and its parameters"

Fig.7

Coordinate system ｛FO｝ of swing foot"

Fig.8

Determination of waypoints of body trajectory"

Fig.9

Distribution of stability margin within DST"

Fig.10

Internal structure and model structure of GRU unit"

Fig.11

Flow chart of acquisition process of T"

Fig.12

Sample experimental scenes to get the training set"

Table 1

Simulation environment parameter settings"

Fig.13

Mean absolute error of different values of k"

Fig.14

Test results of RNN prediction model"

Fig.15

Test terrain"

Fig.16

Screenshot of robot motion process"

Fig.17

Change of roll angle and its phase diagram in the process of robot walking"

Fig.18

Changing curve of ?^i+1 during walking process"

Fig.19

Position variation curve of COG in side direction with respect to moving direction"

Fig.20

Velocity and acceleration variation curves of robot's body during robot walking process"

Fig.21

Change of the roll angle of body during the movement of the robot"

Fig.22

Energy consumption of robot in motion"