A multi-legged biomimetic robot with double-motion modes and 4-DOF-balance tail

Due to the capability of operation in unknown environments, multi-Iegged robots present significant advantages over traditional vehicles with wheels or tracks. In this paper, a multi-Iegged biomimetic robot with double-motion modes and 4-DOF-balance tail is developed. It is composed of six 3-DOF legs, a 1-DOF waist, and a 4-DOF tail. The legs can be partitioned into 2-leg and 4-leg groups by the waist joint. Hence the robot can move with two modes: 4-leg movement (i.e. quadruped mode) with 2-arm/leg manipulation, and 6-leg movement (i.e. hexapod mode). The 4-DOF tail can be used to balance and support the body when necessary, especially climbing high stairs or manipulating heavy loads. It is also can be used as a manipulator to perform the tasks. The embedded control system is developed based on an Acorn RISC Machine (ARM) microprocessor. The wireless communication between the host computer and the robot is realized. Then, the center of gravity is calculated. Furthermore, the stability margin criterion is defined and used to optimize the crawling gait of quadruped mode. Finally, the biomimetic robot prototype is developed and experimented. Experiment results of climbing stairs and manipulating load verify the movement capability, transformation capability, operation capability, and remote operation capability.