Novel Angled Spoke-Based Mobile Robot Design for Agile Locomotion With Obstacle-Overcoming Capability

This article introduces a new mobile robot with angled spoke-based wheels (ASWs). An ASW is designed by analyzing the combination of the assembling angle with the spokes and the assembling angle with the wheel shaft. It has a specific trajectory in which the spokes are perpendicular to and parallel to the ground simultaneously. Therefore, this wheel is in contact with the ground similar to a conventional wheel, but the wheel trajectory does not exceed the height of the spoke length. Therefore, the robot offers an advantage in that various devices can be freely installed on its upper part. Owing to the geometrical features of the wheel, the wheel shaft is assembled at an angle of 45° on the chassis, and 90°-bevel gears are used to maximize space efficiency. The robot is 85-mm long and weighs 208 g. Using the proposed spoke wheel, the robot can travel on carpet at a sustained speed of 18 body-lengths per second. With regard to overcoming obstacles, the robot can overcome a height of 0.7 times the spoke length. Moreover, it can climb continuous obstacles having a staircase angle of 37.5° and overcome an irregular shape and an arbitrarily formed height of obstacles like a tangled rope. It was also confirmed that the robot could carry the same weight as its own without any significant drop in speed.