Path Tracking Experimentation With Epi.q-Mod 2: An Obstacle Climbing Mobile Robot

In this paper, an experimental activity on the path tracking for a hybrid wheeled-legged mobile robot is presented. The activity has been conducted on the Epi.q-Mod 2 prototype, a mobile robot with obstacle climbing ability. This feature has been obtained using a smart rotating leg architecture. Unfortunately, this solution introduces complexity on the kinematic and dynamic modeling of the robot. In order to understand the behavior of the robot during the motion on a generic trajectory, an open loop position controller has been implemented. In particular, the experimental robot trajectory has been reconstructed from odometric quantities through a simplified kinematic model. This trajectory has been compared with the trajectory obtained from a multibody model of the real prototype in order to evaluate the differences between the two approaches. This activity represents a preliminary step for the development of a self-guidance vehicle. In future works the developed model will be used to provide a position feedback for a closed loop position controller without the necessity to use additional sensors.