Hangzhou, China — October 25, 2025. Gourav Moger, a PhD student and researcher at the Institute of Smart Systems and Artificial Intelligence (ISSAI), presented his latest work on advanced robotic mobility at the prestigious IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2025), held in Hangzhou, China, from October 19 to 25, 2025.
His paper, titled “Improbability Roller-2: A Hybrid Mobile Robot with Variable-Diameter Transformable Wheels,” was developed under the supervision of Prof. Huseyin Atakan Varol, Founding Director of ISSAI. The research introduces the Improbability Roller-2, an upgraded version of a terrain-adaptive mobile robot designed to overcome the challenges of locomotion in complex and unstructured environments such as snow, gravel, uneven ground, and confined indoor spaces.
The Improbability Roller-2 features a variable-diameter wheel mechanism utilizing a folding-linkage structure that allows the robot to dynamically adjust its wheel size in real time. The system integrates a dual steering strategy, combining differential drive and wheel-size disparity control, which significantly enhances the robot’s maneuverability and adaptability across diverse terrains.
Experimental validations demonstrated the robot’s ability to traverse slopes, loose surfaces, and confined spaces with improved terrain adaptability and simplified mechanical design. With a higher size-change ratio and more efficient structure, the Improbability Roller-2 represents a notable step forward in mobile robotics for uncertain environments.
Read the full paper: techrxiv.org/doi/full/10.36227/techrxiv.175259035.54719703/v2
Watch the video demonstration: youtube.com/watch?v=qzT-wChHw04