Designing and implementing a modular mechatronics infrastructure for autonomous robotic planetary exploration

Abstract

Traditionally, the robotic vehicles to be sent to other celestial bodies carry with them all the instruments and tools necessary for the mission. With this approach these units are built as unique. They are heavy, complex, costly and do not present any interchangeable parts that could be replaced in the event of permanent failure. However, for future missions, agencies, institutes and commercial companies have been developing robotics systems based on the concept of modular robotics. This new strategy becomes critical for planetary exploration because it is able to reduce load, costs and development time. ARCHES, the German Aerospace Center (DLR) multi-robot system project, is in line with this modern design methodology. Cooperation among robots and modularity are the core of its structure. These characteristics are present in the collaboration between the rovers and the unmanned aerial vehicle (UAV) during navigation tasks, or when the Light Rover Unit (LRU) interacts to changeable manipulator tools and payload boxes through its robotic arm and its standardized electromechanical interface. Examples of these dockable modules include scientific packages, power supply systems, communication and data acquisition architectures, soil sample storage units, and specific purpose end-effectors. The focus of this work is in the design and implementation of a mechatronics infrastructure (MI) which encompasses the docking interface, the payload modules, and the power and data management electronics board in the interior of each box. These three elements are essential for the extension of the capabilities of the rover and the enhancement of the robotics systems according to the tasks to be performed in the field. This will ensure that robots can cooperate with each other either in scientific missions or in the construction and management of large structures such as habitats, power grids and mining facilities. The MI’s hardware and software development approach applied to this thesis was the Model-Based Engineering (MBE). This methodology was implemented with the purpose of standardizing the several interfaces and reducing the fault occurrence likelihood during the integration process. However, unlike in industry, it was adapted to the research center’s experimental nature with the introduction of some agile and low cost methods between the MBE’s stages. Finally, it is important to highlight that modularity and standardization were considered at all levels of the infrastructure. From the robotics systems to the internal architecture of each payload module, these two concepts are able to provide versatility and reliability to the cooperative robotic network. This will improve how robots solve problems and perform complex tasks in planetary exploration missions.