Petri-net-based coordination motion control for legged robot

Legged robot generally moves according to the preplanned gait, which cannot coordinate the motions among the legs with environment. Petri-net is a graphic assembling net model that can be applied to describe and control the dynamic behaviors in multi-agent system. Considering the motion characters of legged robot, this paper proposed a single-leg Petri-net control model for legged robot, and defined the corresponding model parameters. As an example, five such models were assembled to construct the coordination motion control model for the five-legged robot we developed. On this base, the reachable marking graph including all moving states of the five-legged robot was calculated and expressed. Applying the Petri-net model, a new free gait was presented. At last, the motion of five-legged robot crossing grooves in discrete area was simulated. The results show that the five-legged robot can adapt to the environment automatically with the Petri-net control model in this paper.