A snake-like robot based on a spatial linkage mechanism and its kinematics

In this paper, a snake-like robot based on a spatial linkage mechanism is proposed, and the reasonable structural parameters of the mechanism are obtained by performing kinematic simulation. The robot composes of nine modules that are connected by universal joint, and two servomotors are mounted on each module. The two motors drive two cranks, which drive another module by links with two spherical joints. The spatial linkage mechanism makes the wriggling locomotion smoother and more snake-like in its movement. Then the kinematics of the spatial linkage mechanism is developed, and a path planning based on Serpenoid curve is introduced. The optimized parameters of joint relative angles are further obtained to improve the performance of wriggling motion. The experiments in this paper confirm that the robot has ability to realize several motion modes, including wriggling, left swerve, right swerve, and uplifting head and so on.