Tesis Doctoral para la obtención del Título de Grado de Doctor. xiii, 166 p. : il., diagr. Fecha de defensa de la Tesis Doctoral: 7 de julio de 2014. Calificación: Sobresaliente cum laudem ; Robots have constantly been moving towards better design and increased predictability in task execution, leading to expanding and increasing robot presence in several fields and applications. One of which is modular robots in large scientific facilities. Modular robots are characterised for not having a fixed configuration but this presents challenges that need to be overcome, to benefit from the large set of advantages. The large scientific facilities presents a challenging environment for robot deployment due to the presence of hazard like ionising radiation and access controlled complicated environment. This thesis explains, the elements of criteria & constraints, hardware design of the robot system and connector mechanism, applications and RAMS (Reliability, Availability, Maintainability and Safety) approach. The basic applications in maintenance tasks is presented along with advanced applications of cooperation, collaboration and integration with planning tool using robot prototype and simulation results. This work extends the use of modular robotic systems to prevent human interventions for maintenance tasks in workspaces with ionising radiation hazard. The different research performed towards improving the RAMS aspects of robot deployment are presented with experiments and results. They focus on mobile robot energy optimisation, force sensorless estimation of external force and energy perspective for bilateral control in telemanipulation. The thesis assesses the use of a modular robot system to perform maintenance and inspection tasks such as, remote inspection, manipulation and cooperation with deployed or existing robotic systems inside the facilities. The proposed heterogeneous modular robotic system is evaluated using simulations and the prototype across selected robot configuration to perform tasks. Results obtained, show the advantages and ability of the modular robot to perform the necessary maintenance tasks, as well as its flexibility to adapt and evolve depending on the future needs. Therefore, proving to be a possible solution for inclusion in large scientific facilities to perform maintenance tasks. ; Peer Reviewed