Design and Development of an Armadillo-Inspired Robot With Multiple Locomotion Modes

The diversification of locomotion modes can expand the movement range of mobile robots, and enhance their adaptability to complex environments. While the combination of two locomotion modes is quite common, there is still considerable scope for enhancing the environmental adaptability of such robots. In this article, an armadillo-inspired robot (AIRO) with two motion modes, crawling, and rolling, is designed and developed. According to the proposed mechanism design method based on layered constraints, a one-degree of freedom six-bar trunk mechanism is designed and evaluated according to the kinematic chain and the actual configurations, which can realize the switching between crawling and rolling modes with only one motor, and has the advantages of simple control and high structural stiffness, and then the C-shaped arc legs are designed to satisfy the kinematic requirements. Finally, a single/multiple motion modes performance score formula is proposed to quantitatively evaluate the robot's mobility performance based on the indexes such as stability, energy consumption, and speed. The developed prototype of AIRO weighs 2.35 kg and has a maximum size of 469.6 mm × 246.6 mm × 143.2 mm. Experimental results demonstrate that AIRO achieves a maximum crawling speed of 0.192 m/s and a maximum rolling speed of 0.464 m/s on flat terrain, which provides good adaptability to complex terrain. The research results provide a reference for the development of similar robots with multiple motion modes.