MOBINN: Stair-Climbing Mobile Robot With Novel Flexible Wheels

With the recent advancements in delivery service robots, the necessity for stair climbing in indoor and outdoor environments has increased. However, stairs are challenging obstacles for robots to overcome. Most studies in the field of delivery robots have focused on traversing even terrains, such as roads and aisles. However, delivery service robots should be capable of climbing stairs in both indoor and outdoor environments. The main purpose of this study is to develop MOBINN, a mobile balancing robot that is capable of climbing stairs for delivery services. MOBINN has novel flexible wheels that can adapt to the shape of the stairs and reduce the torque needed for climbing them. Due to the advantages of flexible wheels, MOBINN can climb stairs without needing an additional degree of freedom. The head structure is designed to reduce damage to delivery packages as the robot maintains a horizontal orientation when climbing stairs. The design also includes an linear quadratic regulator (LQR)-based motion controller and observer for stair climbing. This study experimentally verified that the novel flexible wheels lowered the required torque and enabled stable stair climbing.