Novel Hybrid Leg-Track Locomotion Robot and its Stability Analysis Using a Unified Methodology

Abstract This paper proposes a novel hybrid robotic locomotion and discusses the development of a unified approach that can analyse legged and track modes of locomotion simultaneously. A hybrid locomotion robot designed using a combination of track and legs is suitable for safe manoeuvrability on dangerous uneven terrain, such as in minefields. Modelling a hybrid locomotion is difficult because of the complex kinematics and dynamics of different modes of locomotion (e.g. legged, track, and wheeled), when used simultaneously. The thrust of this work is, establishing the equivalence of a serial manipulator configuration for modelling tracked locomotion similar to legged locomotion. The spatial motion of the hybrid system is analysed by decomposing into serial manipulators and using suitable constraints. A novel approach to study stability is also presented for computing Multiple Zero Moment Point (MZMP) for the proposed robot that consists of many serial manipulator systems. The stability margins are determined using the correlation between MZMP and combined Zero Moment Point (ZMP), which provide information to identify the unstable dynamic sub systems that can then be rectified in real-time operations. In this paper, the design of the robot using leg and track locomotion is described, and the kinematic, dynamic and stability simulations conducted on the hybrid robotic locomotion using the unified approach are presented.