  We have been developing human-sized biped robots based on passive dynamic
mechanisms. In human locomotion, the muscles activate at the same rate relative
to the gait cycle during running. To achieve adaptive running for robots, such
characteristics should be reproduced to yield the desired effect, In this
study, we designed a central pattern generator (CPG) involving fast and slow
adaptation to achieve human-like running using a simple spring-mass model and
our developed bipedal robot, which is equipped with actuators that imitate the
human musculoskeletal system. Our results demonstrate that the CPG-based
controller with fast and slow adaptations, and a adjustable actuator control
timing can reproduce human-like running. The results suggest that the CPG
contributes to the adjustment of the muscle activation timing in human running.
