ZBOT: A Novel Modular Robot Capable of Active Transformation from Snake to Bipedal Configuration through RL

Abstract

In recent years, significant progress has been made in the prototype design and control methodologies of modular snake robots. However, there is still relatively little research on the potential enabled by the active morphological transformation of robots. This paper presents a novel modular snake robot capable of morphing into a bipedal configuration. The robot, ZBOT, is composed of some independent and homogeneous unit modules (named ZBot) connected in series. Each ZBot module has a dual-motor-driven 1-DoF rotational joint, which can rotate continuously, provide a large output torque and achieve backlash elimination. There are four connection orientations between adjacent modules. This paper proposes an articulation configuration, which enables the snake robot to achieve the active transformation from a snake form to a bipedal form. Meanwhile, through reinforcement learning (RL), movements including the stand-up gait are trained and verified in the IsaacSim/Lab simulation environment. This research will advance snake robots beyond surface-dependent locomotion, endowing them with more possibilities, unlocking greater potential for versatile applications.