270 research outputs found
Credit assignment for collective multiagent RL with global rewards
National Research Foundation (NRF) Singapore under its Corp Lab @ University scheme; Fujitsu Limite
Multi-Agent Credit Assignment in Stochastic Resource Management Games
Multi-Agent Systems (MAS) are a form of distributed intelligence, where multiple autonomous agents act in a common environment. Numerous complex, real world systems have been successfully optimised using Multi-Agent Reinforcement Learning (MARL) in conjunction with the MAS framework. In MARL agents learn by maximising a scalar reward signal from the environment, and thus the design of the reward function directly affects the policies learned. In this work, we address the issue of appropriate multi-agent credit assignment in stochastic resource management games. We propose two new Stochastic Games to serve as testbeds for MARL research into resource management problems: the Tragic Commons Domain and the Shepherd Problem Domain. Our empirical work evaluates the performance of two commonly used reward shaping techniques: Potential-Based Reward Shaping and difference rewards. Experimental results demonstrate that systems using appropriate reward shaping techniques for multi-agent credit assignment can achieve near optimal performance in stochastic resource management games, outperforming systems learning using unshaped local or global evaluations. We also present the first empirical investigations into the effect of expressing the same heuristic knowledge in state- or action-based formats, therefore developing insights into the design of multi-agent potential functions that will inform future work
Multiagent Deep Reinforcement Learning: Challenges and Directions Towards Human-Like Approaches
This paper surveys the field of multiagent deep reinforcement learning. The
combination of deep neural networks with reinforcement learning has gained
increased traction in recent years and is slowly shifting the focus from
single-agent to multiagent environments. Dealing with multiple agents is
inherently more complex as (a) the future rewards depend on the joint actions
of multiple players and (b) the computational complexity of functions
increases. We present the most common multiagent problem representations and
their main challenges, and identify five research areas that address one or
more of these challenges: centralised training and decentralised execution,
opponent modelling, communication, efficient coordination, and reward shaping.
We find that many computational studies rely on unrealistic assumptions or are
not generalisable to other settings; they struggle to overcome the curse of
dimensionality or nonstationarity. Approaches from psychology and sociology
capture promising relevant behaviours such as communication and coordination.
We suggest that, for multiagent reinforcement learning to be successful, future
research addresses these challenges with an interdisciplinary approach to open
up new possibilities for more human-oriented solutions in multiagent
reinforcement learning.Comment: 37 pages, 6 figure
Partner Selection for the Emergence of Cooperation in Multi-Agent Systems Using Reinforcement Learning
Social dilemmas have been widely studied to explain how humans are able to
cooperate in society. Considerable effort has been invested in designing
artificial agents for social dilemmas that incorporate explicit agent
motivations that are chosen to favor coordinated or cooperative responses. The
prevalence of this general approach points towards the importance of achieving
an understanding of both an agent's internal design and external environment
dynamics that facilitate cooperative behavior. In this paper, we investigate
how partner selection can promote cooperative behavior between agents who are
trained to maximize a purely selfish objective function. Our experiments reveal
that agents trained with this dynamic learn a strategy that retaliates against
defectors while promoting cooperation with other agents resulting in a
prosocial society.Comment:
- …