Dual-tracked mobile robot for motion in challenging terrains

In this paper we present a novel design for a dual tracked mobile robot. The robot is designed for safe, stable and reliable motion in challenging terrains, tunnels and confined spaces. It consists of two tracked platforms connected with a semi-passive mechanism. Sensors attached to the connecting mechanism provide redundant localization data that improves the vehicle's autonomous dead reckoning. Each tracked platform mechanically backs-up the other platform, resulting in a more robust and reliable operation. The load share between the platforms enables high payload to weight ratio even on soft and slippery terrains. The robot's configurations makes it suitable for motion in confined spaces such as underground tunnels, collapsed structures, pipes and caves. The paper presents the mechanical design of the robot, its kinematic model, stability analysis and a motion planner. Experimental results conducted on prototype models in various types of environments verify the robot capabilities to operate successfully on challenging terrains. The dual tracked robot is capable of climbing slopes 50% steeper than a single robot can. Moreover, the improved odometry system shows high accuracy with 2% error of the total travel distance.