Radial-skeleton shape-changing robots are rough-terrain robots and
exhibit many advantages in the aspect of mobility, such as excellent
terrain adaptability, light weight, good portability, and stable
configuration. However, existing gait generation methods are rough and
yield low tracking accuracy because the leg-ground contact friction is
difficult to predict and control. In addition, no closed-loop control
scheme has been proposed for this type of robot. In this study, we
designed a 12-legged radial-skeleton robot with a radial expansion ratio
of 2.08. Based on the prototype, we proposed a high-precision gait
generation algorithm that can be used to any multi-legged
radial-skeleton robot and implemented a closed-loop control scheme for
accurate path tracking. Combining the contact friction and multi-body
dynamics model, the robot prototype exhibits the advantages of
omnidirectional motion, high-precision tracking, and motion robustness.
By manufacturing a prototype and conducting comparative experiments, we
verified that the proposed method yields good performance in terms of
trajectory tracking accuracy and robustness in the cases of unknown
terrain and interference.