Goto

Collaborating Authors

 Reinforcement Learning


Army advances learning capabilities of drone swarms

#artificialintelligence

Army researchers developed a reinforcement learning approach that will allow swarms of unmanned aerial and ground vehicles to optimally accomplish various missions while minimizing performance uncertainty.Swarming is a method of operations where multiple autonomous systems act as a cohesive unit by actively coordinating their actions.Army researchers said future multi-domain battles will require swarms of dynamically coupled, coordinated heterogeneous mobile platforms to overmatch enemy capabilities and threats targeting U.S. forces.The Army is looking to swarming technology to be able to execute time-consuming or dangerous tasks, said Dr. Jemin George of the U.S. Army Combat Capabilities Development Command's Army Research Laboratory."Finding optimal guidance policies for these swarming vehicles in real-time is a key requirement for enhancing warfighters' tactical situational awareness, allowing the U.S. Army to dominate in a contested environment," George said.Reinforcement learning ...


Maintaining the illusion of reality: transfer in RL by keeping agents in the DARC

AIHub

Reinforcement learning (RL) is often touted as a promising approach for costly and risk-sensitive applications, yet practicing and learning in those domains directly is expensive. It costs time (e.g., OpenAI's Dota2 project used 10,000 years of experience), it costs money (e.g., "inexpensive" robotic arms used in research typically cost 10,000 to 30,000 dollars), and it could even be dangerous to humans. How can an intelligent agent learn to solve tasks in environments in which it cannot practice? For many tasks, such as assistive robotics and self-driving cars, we may have access to a different practice area, which we will call the source domain. While the source domain has different dynamics than the target domain, experience in the source domain is much cheaper to collect.


Comparison of Model Predictive and Reinforcement Learning Methods for Fault Tolerant Control

arXiv.org Artificial Intelligence

A desirable property in fault-tolerant controllers is adaptability to system changes as they evolve during systems operations. An adaptive controller does not require optimal control policies to be enumerated for possible faults. Instead it can approximate one in real-time. We present two adaptive fault-tolerant control schemes for a discrete time system based on hierarchical reinforcement learning. We compare their performance against a model predictive controller in presence of sensor noise and persistent faults. The controllers are tested on a fuel tank model of a C-130 plane. Our experiments demonstrate that reinforcement learning-based controllers perform more robustly than model predictive controllers under faults, partially observable system models, and varying sensor noise levels.


Fault-Tolerant Control of Degrading Systems with On-Policy Reinforcement Learning

arXiv.org Artificial Intelligence

We propose a novel adaptive reinforcement learning control approach for fault tolerant control of degrading systems that is not preceded by a fault detection and diagnosis step. Therefore, \textit{a priori} knowledge of faults that may occur in the system is not required. The adaptive scheme combines online and offline learning of the on-policy control method to improve exploration and sample efficiency, while guaranteeing stable learning. The offline learning phase is performed using a data-driven model of the system, which is frequently updated to track the system's operating conditions. We conduct experiments on an aircraft fuel transfer system to demonstrate the effectiveness of our approach.


GRIMGEP: Learning Progress for Robust Goal Sampling in Visual Deep Reinforcement Learning

arXiv.org Artificial Intelligence

Although recent work in reinforcement learning has shown that robots can learn complex individual skills such as grasping [2], locomotion [3, 4], and manipulation tasks [5], designing reinforcement learning algorithms that perform well in sparse reward scenarios is still an open challenge of artificial intelligence. Standard reinforcement learning algorithms struggle in the sparse reward scenario because they rely on simple exploration behavior such as random actions. As a result, learning complex tasks often requires manually collecting examples [6, 7] or running learning algorithms over a long period of time which may not be possible in real life scenarios. Designing better exploration schemes would help agents autonomously discover interesting features that can then be used to learn the long term objective. Developing efficient exploration algorithms would thus help create a more autonomous learning agent. Several approaches have been considered in order to improve the exploration performances of reinforcement learning algorithms. One approach is to reward the agent for discovering novel observations in the form of an intrinsic reward that is added to the original reward of the environment [8].


Bilevel Learning Model Towards Industrial Scheduling

arXiv.org Artificial Intelligence

Automatic industrial scheduling, aiming at optimizing the sequence of jobs over limited resources, is widely needed in manufacturing industries. However, existing scheduling systems heavily rely on heuristic algorithms, which either generate ineffective solutions or compute inefficiently when job scale increases. Thus, it is of great importance to develop new large-scale algorithms that are not only efficient and effective, but also capable of satisfying complex constraints in practice. In this paper, we propose a Bilevel Deep reinforcement learning Scheduler, \textit{BDS}, in which the higher level is responsible for exploring an initial global sequence, whereas the lower level is aiming at exploitation for partial sequence refinements, and the two levels are connected by a sliding-window sampling mechanism. In the implementation, a Double Deep Q Network (DDQN) is used in the upper level and Graph Pointer Network (GPN) lies within the lower level. After the theoretical guarantee for the convergence of BDS, we evaluate it in an industrial automatic warehouse scenario, with job number up to $5000$ in each production line. It is shown that our proposed BDS significantly outperforms two most used heuristics, three strong deep networks, and another bilevel baseline approach. In particular, compared with the most used greedy-based heuristic algorithm in real world which takes nearly an hour, our BDS can decrease the makespan by 27.5\%, 28.6\% and 22.1\% for 3 largest datasets respectively, with computational time less than 200 seconds.


Goal-Aware Prediction: Learning to Model What Matters

arXiv.org Artificial Intelligence

Learned dynamics models combined with both planning and policy learning algorithms have shown promise in enabling artificial agents to learn to perform many diverse tasks with limited supervision. However, one of the fundamental challenges in using a learned forward dynamics model is the mismatch between the objective of the learned model (future state reconstruction), and that of the downstream planner or policy (completing a specified task). This issue is exacerbated by vision-based control tasks in diverse real-world environments, where the complexity of the real world dwarfs model capacity. In this paper, we propose to direct prediction towards task relevant information, enabling the model to be aware of the current task and encouraging it to only model relevant quantities of the state space, resulting in a learning objective that more closely matches the downstream task. Further, we do so in an entirely self-supervised manner, without the need for a reward function or image labels. We find that our method more effectively models the relevant parts of the scene conditioned on the goal, and as a result outperforms standard task-agnostic dynamics models and model-free reinforcement learning.


fabiopardo/tonic

#artificialintelligence

Welcome to the Tonic deep reinforcement learning library. Modularity: Building blocks for creating RL agents, such as models, replays, or exploration strategies, are implemented as configurable modules. Readability: Agents are written in a simple way with an identical API and logs are nicely displayed on the terminal with a progress bar. Fair comparison: The training pipeline is unique and compatible with all Tonic agents and environments. Agents are defined by their core ideas while general tricks/improvements like non-terminal timeouts, observation normalization and action scaling are shared.


Online Multi-modal Person Search in Videos

arXiv.org Artificial Intelligence

The task of searching certain people in videos has seen increasing potential in real-world applications, such as video organization and editing. Most existing approaches are devised to work in an offline manner, where identities can only be inferred after an entire video is examined. This working manner precludes such methods from being applied to online services or those applications that require real-time responses. In this paper, we propose an online person search framework, which can recognize people in a video on the fly. This framework maintains a multimodal memory bank at its heart as the basis for person recognition, and updates it dynamically with a policy obtained by reinforcement learning. Our experiments on a large movie dataset show that the proposed method is effective, not only achieving remarkable improvements over online schemes but also outperforming offline methods.


Hierarchial Reinforcement Learning in StarCraft II with Human Expertise in Subgoals Selection

arXiv.org Artificial Intelligence

This work is inspired by recent advances in hierarchical reinforcement learning (HRL) (Barto and Mahadevan 2003;Hengst 2010), and improvements in learning efficiency with heuristic-based subgoal selection and hindsight experience replay (HER)(Andrychowicz et al. 2017; Levy et al. 2019). We propose a new method to integrate HRL, HER and effective subgoal selection based on human expertise to support sample-efficient learning and enhance interpretability of the agent's behavior. Human expertise remains indispensable in many areas such as medicine (Buch, Ahmed, and Maruthappu 2018) and law (Cath 2018), where interpretability, explainability and transparency are crucial in the decision making process, for ethical and legal reasons. Our method simplifies the complex task sets for achieving the overall objectives by decomposing into subgoals at different levels of abstraction. Incorporating relevant subjective knowledge also significantly reduces the computational resources spent in exploration for RL, especially in high speed, changing, and complex environments where the transition dynamics cannot be effectively learned and modelled in a short time. Experimental results in two StarCraft II (SC2) minigames demonstrate that our method can achieve better sample efficiency than flat and end-to-end RL methods, and provide an effective method for explaining the agent's performance.