Citation: Gomez, V.; Hernando, M.; Aguado, E.; Sanz, R.; Rossi, C. ROBOMINER: Development of a Highly Configurable and Modular Scaled-Down Prototype of a Mining Robot. Machines 2023, 11, 809. https://doi.org/10.3390/ machines11080809 Academic Editor: Dan Zhang Received: 6 July 2023 Revised: 4 August 2023 Accepted: 5 August 2023 Published: 7 August 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). machines Article ROBOMINER: Development of a Highly Configurable and Modular Scaled-Down Prototype of a Mining Robot Virgilio Gomez 1, * , Miguel Hernando 1 , Esther Aguado 1,2 , Ricardo Sanz 2 and Claudio Rossi 1 1 Centre for Automation and Robotics, Universidad Politécnica de Madrid-CSIC, 28006 Madrid, Spain; miguel.hernando@upm.es (M.H.); e.aguado@upm.es (E.A.); claudio.rossi@upm.es (C.R.) 2 Autonomous Systems Laboratory, Universidad Politécnica de Madrid, 28006 Madrid, Spain; ricardo.sanz@upm.es * Correspondence: virgilio.gomez.lambo@upm.es Abstract: Historically, mining operations have faced numerous challenges, including safety hazards, inefficiencies, and environmental concerns. However, recent advances in robotics, automation, and artificial intelligence have presented opportunities for the mining industry. The ROBOMINERS project, a Horizon 2020 European Union initiative, aims to revolutionize the mining ecosystem by implementing disruptive robotic concepts. One such concept is resilience, which involves enabling mining robots to reconfigure morphologically during operation. This article presents the development of a modular robotic system that focuses on modularity and self-assembly to provide insight into developing a highly adaptable and compact solution for future mining robots. The robotic system is composed of a set of highly configurable modular robotic platforms that can be reconfigured with other robotic modules or submodules to form more complex systems to perform different tasks. Several module configurations are presented, and different locomotion experiments were carried out to test the ability of the modules to navigate unstructured environments. The modules exhibited great maneuverability in unstructured terrain and demonstrated self-assembly and reconfiguration capabilities during operation. This is a foundational step towards the long-term goal of developing compact autonomous agents capable of self-assembly and mining task execution. Keywords: modular robots; reconfigurable robots; robotic systems; mining robots 1. Introduction Mining operations are crucial for meeting growing global demand for natural re- sources. However, traditional industry mining methods in are often associated with signifi- cant challenges, such as safety hazards, inefficiencies, and environmental concerns [1]. In recent years, remarkable progress [2–5] has emerged in robotics, automation, and artificial intelligence that offer the potential to address these challenges and unlock new possi- bilities. While these advances have shown considerable potential, there is still room for improvement in adaptability, scalability, and overall performance. One approach with great potential is the implementation of modular robotic systems [6]. Consisting of individual robot modules that can be interconnected and reconfigured, these systems provide inherent flexibility and versatility to allow robots to adapt to changing conditions, perform complex tasks, and achieve different goals. The ROBOMINERS project (https://robominers.eu), [Accessed date 6 July 2023] funded under the European Union’s Horizon 2020 research and innovation program, is strategically focused on introducing disruptive robotic concepts to facilitate access to minerals in Europe, thereby shaping a new mining ecosystem. Among its key aspects is resilience, which entails providing mining robots with the ability to complete tasks when new situations or disturbances arise. One of the main objectives of the project is to provide resilience towards autonomous operation, where robotic modules are sent down in pieces to the mine through a large diameter borehole and self-assembled to form a fully functional Machines 2023, 11, 809. https://doi.org/10.3390/machines11080809 https://www.mdpi.com/journal/machines