Multi-Agent Reinforcement Learning (MARL) algorithms face two main difficulties: the curse of dimensionality, and environment non-stationarity due to the independent learning processes carried out by the agents concurrently. In this paper we formalize and prove the convergence of a Distributed Round Robin Q-learning (D-RR-QL) algorithm for cooperative systems. The computational complexity of this algorithm increases linearly with the number of agents. Moreover, it eliminates environment non sta tionarity by carrying a round-robin scheduling of the action selection and execution. That this learning scheme allows the implementation of Modular State-Action Vetoes (MSAV) in cooperative multi-agent systems, which speeds up learning convergence in over-constrained systems by vetoing state-action pairs which lead to undesired termination states (UTS) in the relevant state-action subspace. Each agent’s local state-action value function learning is an independent process, including the MSAV policies. Coordination of locally optimal policies to obtain the global optimal joint policy is achieved by a greedy selection procedure using message passing. We show that D-RR-QL improves over state-of-the-art approaches, such as Distributed Q-Learning, Team Q-Learning and Coordinated Reinforcement Learning in a paradigmatic Linked Multi-Component Robotic System (L-MCRS) control problem: the hose transportation task. L-MCRS are over-constrained systems with many UTS induced by the interaction of the passive linking element and the active mobile robots.

The IEC61499 is an open standard for distributed control and automation. The interface between control software and hardware or communications is achieved by means of the so-called Service Interface Function Blocks (SIFB). This paper presents the guidelines to build communication SIFBs based on the emerging OMG DDS (Data Distribution Service) middleware. This specification implements in a very efficient way the Publisher/Subscriber paradigm providing significant QoS configuration possibilities. These characteristics make DDS suitable for implementing the communications among time-critical devices. By using these DDS-SIFBs within IEC61499 code generation tools, the designers of the distributed applications will be allowed to use this powerful technology in the new distributed applications.