115,318 research outputs found
Counterfactual Multi-Agent Policy Gradients
Cooperative multi-agent systems can be naturally used to model many real
world problems, such as network packet routing and the coordination of
autonomous vehicles. There is a great need for new reinforcement learning
methods that can efficiently learn decentralised policies for such systems. To
this end, we propose a new multi-agent actor-critic method called
counterfactual multi-agent (COMA) policy gradients. COMA uses a centralised
critic to estimate the Q-function and decentralised actors to optimise the
agents' policies. In addition, to address the challenges of multi-agent credit
assignment, it uses a counterfactual baseline that marginalises out a single
agent's action, while keeping the other agents' actions fixed. COMA also uses a
critic representation that allows the counterfactual baseline to be computed
efficiently in a single forward pass. We evaluate COMA in the testbed of
StarCraft unit micromanagement, using a decentralised variant with significant
partial observability. COMA significantly improves average performance over
other multi-agent actor-critic methods in this setting, and the best performing
agents are competitive with state-of-the-art centralised controllers that get
access to the full state
Embodied Artificial Intelligence through Distributed Adaptive Control: An Integrated Framework
In this paper, we argue that the future of Artificial Intelligence research
resides in two keywords: integration and embodiment. We support this claim by
analyzing the recent advances of the field. Regarding integration, we note that
the most impactful recent contributions have been made possible through the
integration of recent Machine Learning methods (based in particular on Deep
Learning and Recurrent Neural Networks) with more traditional ones (e.g.
Monte-Carlo tree search, goal babbling exploration or addressable memory
systems). Regarding embodiment, we note that the traditional benchmark tasks
(e.g. visual classification or board games) are becoming obsolete as
state-of-the-art learning algorithms approach or even surpass human performance
in most of them, having recently encouraged the development of first-person 3D
game platforms embedding realistic physics. Building upon this analysis, we
first propose an embodied cognitive architecture integrating heterogenous
sub-fields of Artificial Intelligence into a unified framework. We demonstrate
the utility of our approach by showing how major contributions of the field can
be expressed within the proposed framework. We then claim that benchmarking
environments need to reproduce ecologically-valid conditions for bootstrapping
the acquisition of increasingly complex cognitive skills through the concept of
a cognitive arms race between embodied agents.Comment: Updated version of the paper accepted to the ICDL-Epirob 2017
conference (Lisbon, Portugal
Generative Exploration and Exploitation
Sparse reward is one of the biggest challenges in reinforcement learning
(RL). In this paper, we propose a novel method called Generative Exploration
and Exploitation (GENE) to overcome sparse reward. GENE automatically generates
start states to encourage the agent to explore the environment and to exploit
received reward signals. GENE can adaptively tradeoff between exploration and
exploitation according to the varying distributions of states experienced by
the agent as the learning progresses. GENE relies on no prior knowledge about
the environment and can be combined with any RL algorithm, no matter on-policy
or off-policy, single-agent or multi-agent. Empirically, we demonstrate that
GENE significantly outperforms existing methods in three tasks with only binary
rewards, including Maze, Maze Ant, and Cooperative Navigation. Ablation studies
verify the emergence of progressive exploration and automatic reversing.Comment: AAAI'2
A Study of AI Population Dynamics with Million-agent Reinforcement Learning
We conduct an empirical study on discovering the ordered collective dynamics
obtained by a population of intelligence agents, driven by million-agent
reinforcement learning. Our intention is to put intelligent agents into a
simulated natural context and verify if the principles developed in the real
world could also be used in understanding an artificially-created intelligent
population. To achieve this, we simulate a large-scale predator-prey world,
where the laws of the world are designed by only the findings or logical
equivalence that have been discovered in nature. We endow the agents with the
intelligence based on deep reinforcement learning (DRL). In order to scale the
population size up to millions agents, a large-scale DRL training platform with
redesigned experience buffer is proposed. Our results show that the population
dynamics of AI agents, driven only by each agent's individual self-interest,
reveals an ordered pattern that is similar to the Lotka-Volterra model studied
in population biology. We further discover the emergent behaviors of collective
adaptations in studying how the agents' grouping behaviors will change with the
environmental resources. Both of the two findings could be explained by the
self-organization theory in nature.Comment: Full version of the paper presented at AAMAS 2018 (International
Conference on Autonomous Agents and Multiagent Systems
Sharp transition towards shared vocabularies in multi-agent systems
What processes can explain how very large populations are able to converge on
the use of a particular word or grammatical construction without global
coordination? Answering this question helps to understand why new language
constructs usually propagate along an S-shaped curve with a rather sudden
transition towards global agreement. It also helps to analyze and design new
technologies that support or orchestrate self-organizing communication systems,
such as recent social tagging systems for the web. The article introduces and
studies a microscopic model of communicating autonomous agents performing
language games without any central control. We show that the system undergoes a
disorder/order transition, going trough a sharp symmetry breaking process to
reach a shared set of conventions. Before the transition, the system builds up
non-trivial scale-invariant correlations, for instance in the distribution of
competing synonyms, which display a Zipf-like law. These correlations make the
system ready for the transition towards shared conventions, which, observed on
the time-scale of collective behaviors, becomes sharper and sharper with system
size. This surprising result not only explains why human language can scale up
to very large populations but also suggests ways to optimize artificial
semiotic dynamics.Comment: 12 pages, 4 figure
- …