Perception of rugged terrain for a walking robot: true confessions and new directions

The Ambler is an autonomous orthogonal walking robot that operates in rugged environments. The mechanism has two stacks and six circulating legs. On top of the Ambler is mounted a laser scanner to obtain 3D data of the local terrain. It is designed for planetary exploration. During the course of walking experiments unexpected shortcomings in the robot´s perception system were noted. Unusual perception sensor behavior, random noise sources, and interaction of the perception system with other system components caused both minor errors and large failures in the system. This paper analyzes the sources of the perception system errors, presents solutions to these problems, and proposes a design for a more robust perception system