서강대학교

초록/요약 도움말

A simple and effective method to realize the locomotion of legged robots is by the design of appropriate joint angle trajectories. Due to the complicated nature of legged locomotion, the desired joint-angle trajectories are often inspired from those of animals. The locomotion of quadruped animals exhibits multiple gait phases, such as walk, trot, canter, and gallop, which may necessitate for the trajectory generation algorithm of a quadruped robot to be able to generate joint-angle trajectories in multiple gait phases. In this thesis, the joint-angles of an animal are expressed as a cyclic basis function, and an input to the basis function is manipulated to realize the joint-angle trajectories in multiple gait phases as desired. To control the desired input of a cyclic basis function, a synchronization function is formulated, by which the motions of legs are designed to have proper ground contact sequences with each other. In the gait of animals, each gait phase is optimal for a certain speed, and thus transition of the gait phases is necessary for effective increase or decrease of the locomotion speed. The classification of the gait phases, however, is discrete, and thus the resultant joint-angle trajectories may be discontinuous due to the transition. For smooth and continuous transition of gait phases, fuzzy logic is utilized in the proposed algorithm. The proposed methods are verified by simulation studies.