An Innovative Mechanical and Control Architecture for a Biomimetic Hexapod for Planetary Exploration

This paper addresses the design of a six legged robot for planetary exploration. The robot is specifically designed for uneven terrains and is biologically inspired on different levels: mechanically as well as in control. A novel structure is developed basing on a (careful) emulation of the cockroach, whose extraordinary agility and speed are principally due to its self-stabilizing posture and specializing legged function. Structure design enhances these properties, in particular with an innovative piston-like scheme for rear legs, while avoiding an excessive and useless complexity. Locomotion control is designed following an analog electronics approach, that in space applications could hold many benefits. In particular, the locomotion control is based on a Cellular Neural Network playing the role of an artificial Central Pattern Generator. Several dynamical simulations were carried out to test the structure and the locomotion control. Simulation results led to the implementation of the first prototype: Gregor I. Experimental tests showed that Gregor I is able to walk at the travel speed of 0.1 body length per second and to successfully negotiate obstacles more than 170% of the height of its center of mass.