| legged robot has the high adaptability to the environment, it can be applied in the fields of scientific investigation, national defense, aerospace exploration etc, in recent years, research on biped humanoid robots and quadruped robots was most exciting topics in the field of robotics .while researchers work completely on the dynamical biped walking and the quadruped walking, there is less study on the dynamical quadruped walking—especially on irregular terrain. Whereas the static quadruped walking can not be applied to irregular terrain, the research of walking dynamically on irregular terrain for an gorilla robot is of great importance.To realize dynamically stable walking on irregular terrain for a quadruped walking robot, the combination of the trajectory planning of the body and leg position and the adaptive attitude control is indispensable. As the legged system has a similar dynamics to that of Three-Dimensional Inverted Pendulum Mode, whose supporting point is equivalently located at the ZMP, what is more , there is dynamical relationship between the Zero Moment Point (ZMP) and the center of gravity (COG) ,So this paper proposed the method that controls the COG of the whole humanoid body system in real-time through the 3-D inverted pendulum based on variable ZMP: First, the irregular terrain analyzed and described, the author proposed an usual obstacles-spanning method, based on the position and the shape of obstacles, the author programmed the smooth trajectory of anklebones. Second, the author introduced a new stability region, and programmed a trajectory of variable ZMP, which was defined as a cosine curve; The author also designed a COG- compensated method to keep the COG's height; Based on dynamics of 3-D inverted pendulum, the author educed the COG's trajectory equation of the robot in the three-leg-support phase, and used third-order splint function to ensure the acceleration continuity of the robot's COG in the four-leg-support phase. At last, walking patterns of the corresponding gait are generated through programmer design. Under the simulation environment of ADAMS software, the 3-D virtual prototype model was built according to actual gorilla robot"GoRoBoT"and the real terrain. Experiment was performed on the... |
