Gait generation and obstacle avoidance of a single leg for a biped

The need of an online gait generator for a biped robot is studied in this paper. For this purpose a model of the walking machine which is modeled as a multibody system is presented first. In order to ensure the success of gait generation, a single-leg-test-bench is used. It consists of a planar leg which is fixed on a frame, walking on a conveyer belt. In order to obtain natural leg motion, a trajectory of the foot point is derived. This trajectory is calculated offline. It enables continuous gait by three parts: a transition phase from an arbitrary starting point to the starting position of the walking cycle. a retract phase and a forward swinging phase. As a result of the continuous transition from the second to the third phase, we obtain the desired motion. This waking cycle is specified by three pattern parameters yielding several different gaits of same type. To perform the same tasks as humans, the leg must have the same mobility. Therefore the possibility of obstacle avoidance is an important part of such walking trajectory. In this paper the leg can react upon obstacles by using sensors at the toe. This reaction is online which means, that the desired foot trajecotry will be created at every timestep by using the same pattern parameters as for the offline gait generator. Computer animations along with experimental results demonstrate the effectiveness of the proposed gait generator.