Stability and adaptability of passive creeping of a snake-like robot

The control of a snake-like robot is a challenging problem because of the complex dynamics and the unknown environment. We have proposed an energy-based method, called passive creeping, to control the serpentine locomotion. This paper lays emphasis on the stability and the adaptability of the method. First, the local orbital stability of the movement is explicated based on the maximal Lyapunov exponent and the recurrence plot. Second, the adaptability to the environment is analyzed, and an optimal adaptive law based on the energy proportion is put into use to perfect the method. The particular advantages of the passive creeping include the comprehensive concept, the explicit control, and the inherent adaptability.