An adaptive locomotion of a quadruped robot on irregular terrain using simple biomimetic oscillator and reflex controllers without visual information

This paper describes the development of an oscillator and reflex-based controller for a quadruped robot that does not use visual information about the physical properties of its environment. The periodic motions of the legs switch between the swing and stance phases based on the oscillator phases. The oscillator phase is reset by the touch sensor signal at the end of each leg when the leg touches the ground. This global feedback loop composes a steady limit cycle of the total periodic dynamics of quadruped locomotion. Reflex actions are also generated against perturbations of the steady locomotion or against sudden disturbances on posture, such as becoming stuck in a hole. This system has the capability to adapt to unknown walking properties on irregular terrain. The proposed controller´s effectiveness and performance were evaluated with numerical simulations and hardware experiments.