Reinforcement Learning
Awesome-META+: Meta-Learning Research and Learning Platform
Wang, Jingyao, Zhang, Chuyuan, Ding, Ye, Yang, Yuxuan
Artificial intelligence technology has already had a profound impact in various fields such as economy, industry, and education, but still limited. Meta-learning, also known as "learning to learn", provides an opportunity for general artificial intelligence, which can break through the current AI bottleneck. However, meta learning started late and there are fewer projects compare with CV, NLP etc. Each deployment requires a lot of experience to configure the environment, debug code or even rewrite, and the frameworks are isolated. Moreover, there are currently few platforms that focus exclusively on meta-learning, or provide learning materials for novices, for which the threshold is relatively high. Based on this, Awesome-META+, a meta-learning framework integration and learning platform is proposed to solve the above problems and provide a complete and reliable meta-learning framework application and learning platform. The project aims to promote the development of meta-learning and the expansion of the community, including but not limited to the following functions: 1) Complete and reliable meta-learning framework, which can adapt to multi-field tasks such as target detection, image classification, and reinforcement learning. 2) Convenient and simple model deployment scheme which provide convenient meta-learning transfer methods and usage methods to lower the threshold of meta-learning and improve efficiency. 3) Comprehensive researches for learning. 4) Objective and credible performance analysis and thinking.
Continuous Episodic Control
Yang, Zhao, Moerland, Thomas M., Preuss, Mike, Plaat, Aske
Abstract--Non-parametric episodic memory can be used to quickly latch onto high-rewarded experience in reinforcement learning tasks. In contrast to parametric deep reinforcement learning approaches in which reward signals need to be backpropagated slowly, these methods only need to discover the solution once, and may then repeatedly solve the task. However, episodic control solutions are stored in discrete tables, and this approach has so far only been applied to discrete action space problems. Deep reinforcement learning (RL) methods have recently Episodic memory is a term that originates from neuroscience demonstrated superhuman performance on a wide range of [9], where it refers to memory that we can quickly tasks, including Gran Turisma [1], StarCraft [2], Go [3], etc. recollect. In the context of RL, this concept has generally been However, in these methods, the weights of neural networks are implemented as a non-parametric (or semi-parametric) table slowly updated over time to match the target predictions based that can be read from and written into rapidly. Information on the encountered reward signal.
Two-Memory Reinforcement Learning
Yang, Zhao, Moerland, Thomas. M., Preuss, Mike, Plaat, Aske
While deep reinforcement learning has shown important empirical success, it tends to learn relatively slow due to slow propagation of rewards information and slow update of parametric neural networks. Non-parametric episodic memory, on the other hand, provides a faster learning alternative that does not require representation learning and uses maximum episodic return as state-action values for action selection. Episodic memory and reinforcement learning both have their own strengths and weaknesses. Notably, humans can leverage multiple memory systems concurrently during learning and benefit from all of them. In this work, we propose a method called Two-Memory reinforcement learning agent (2M) that combines episodic memory and reinforcement learning to distill both of their strengths. The 2M agent exploits the speed of the episodic memory part and the optimality and the generalization capacity of the reinforcement learning part to complement each other. Our experiments demonstrate that the 2M agent is more data efficient and outperforms both pure episodic memory and pure reinforcement learning, as well as a state-of-the-art memory-augmented RL agent. Moreover, the proposed approach provides a general framework that can be used to combine any episodic memory agent with other off-policy reinforcement learning algorithms.
How to Control Hydrodynamic Force on Fluidic Pinball via Deep Reinforcement Learning
Feng, Haodong, Wang, Yue, Xiang, Hui, Jin, Zhiyang, Fan, Dixia
Deep reinforcement learning (DRL) for fluidic pinball, three individually rotating cylinders in the uniform flow arranged in an equilaterally triangular configuration, can learn the efficient flow control strategies due to the validity of self-learning and data-driven state estimation for complex fluid dynamic problems. In this work, we present a DRL-based real-time feedback strategy to control the hydrodynamic force on fluidic pinball, i.e., force extremum and tracking, from cylinders' rotation. By adequately designing reward functions and encoding historical observations, and after automatic learning of thousands of iterations, the DRL-based control was shown to make reasonable and valid control decisions in nonparametric control parameter space, which is comparable to and even better than the optimal policy found through lengthy brute-force searching. Subsequently, one of these results was analyzed by a machine learning model that enabled us to shed light on the basis of decision-making and physical mechanisms of the force tracking process. The finding from this work can control hydrodynamic force on the operation of fluidic pinball system and potentially pave the way for exploring efficient active flow control strategies in other complex fluid dynamic problems.
Just Round: Quantized Observation Spaces Enable Memory Efficient Learning of Dynamic Locomotion
Grossman, Lev, Plancher, Brian
Importantly, unlike simply reducing the number of observations Deep reinforcement learning (DRL) continues to see increased stored in the buffer, which decreases the memory attention by the robotics community due to its footprint at the cost of reduced learning performance, our ability to learn complex behaviors in both simulated and quantization scheme is able to reduce memory usage without real environments. These methods have been successfully impacting the training performance. We present experiments applied to a host of robotic tasks including: dexterous manipulation across four popular simulated robotic locomotion domains, [1], quadrupedal locomotion [2], and high-speed using two of the most popular DRL algorithms, the on-policy drone racing [3]. Despite these successes, DRL remains Proximal Policy Optimization (PPO) and off-policy Soft largely sample inefficient, depending on enormous amounts Actor-Critic (SAC), and find that our approach can reduce of training data to learn. As much of this data is kept in the memory footprint by as much as 4.2 without impacting replay buffers during training, DRL is extremely memory training performance.
Reinforcement Learning with an Abrupt Model Change
Chen, Wuxia, Banerjee, Taposh, George, Jemin, Busart, Carl
The problem of reinforcement learning is considered where the environment or the model undergoes a change. An algorithm is proposed that an agent can apply in such a problem to achieve the optimal long-time discounted reward. The algorithm is model-free and learns the optimal policy by interacting with the environment. It is shown that the proposed algorithm has strong optimality properties. The effectiveness of the algorithm is also demonstrated using simulation results. The proposed algorithm exploits a fundamental reward-detection trade-off present in these problems and uses a quickest change detection algorithm to detect the model change. Recommendations are provided for faster detection of model changes and for smart initialization strategies.
Google robot learns to sort the recyclables left in office waste bins
Waste-sorting robots that have been learning their job while wandering through Google offices can now effectively sort items in bins into recycling, compost and rubbish. One way of teaching machines to perform tasks is by reinforcement learning, in which a robot is told what a successful outcome looks like and is left to figure out how to achieve it by trial and error and a system of feedback, gradually building up an optimal model of what to do.
On the Importance of Exploration for Real Life Learned Algorithms
Gracla, Steffen, Bockelmann, Carsten, Dekorsy, Armin
The quality of data driven learning algorithms scales significantly with the quality of data available. One of the most straight-forward ways to generate good data is to sample or explore the data source intelligently. Smart sampling can reduce the cost of gaining samples, reduce computation cost in learning, and enable the learning algorithm to adapt to unforeseen events. In this paper, we teach three Deep Q-Networks (DQN) with different exploration strategies to solve a problem of puncturing ongoing transmissions for URLLC messages. We demonstrate the efficiency of two adaptive exploration candidates, variance-based and Maximum Entropy-based exploration, compared to the standard, simple epsilon-greedy exploration approach.
Adaptive patch foraging in deep reinforcement learning agents
Wispinski, Nathan J., Butcher, Andrew, Mathewson, Kory W., Chapman, Craig S., Botvinick, Matthew M., Pilarski, Patrick M.
Patch foraging is one of the most heavily studied behavioral optimization challenges in biology. However, despite its importance to biological intelligence, this behavioral optimization problem is understudied in artificial intelligence research. Patch foraging is especially amenable to study given that it has a known optimal solution, which may be difficult to discover given current techniques in deep reinforcement learning. Here, we investigate deep reinforcement learning agents in an ecological patch foraging task. For the first time, we show that machine learning agents can learn to patch forage adaptively in patterns similar to biological foragers, and approach optimal patch foraging behavior when accounting for temporal discounting. Finally, we show emergent internal dynamics in these agents that resemble single-cell recordings from foraging non-human primates, which complements experimental and theoretical work on the neural mechanisms of biological foraging. This work suggests that agents interacting in complex environments with ecologically valid pressures arrive at common solutions, suggesting the emergence of foundational computations behind adaptive, intelligent behavior in both biological and artificial agents.
A Cubic-regularized Policy Newton Algorithm for Reinforcement Learning
Maniyar, Mizhaan Prajit, Mondal, Akash, A., Prashanth L., Bhatnagar, Shalabh
We consider the problem of control in the setting of reinforcement learning (RL), where model information is not available. Policy gradient algorithms are a popular solution approach for this problem and are usually shown to converge to a stationary point of the value function. In this paper, we propose two policy Newton algorithms that incorporate cubic regularization. Both algorithms employ the likelihood ratio method to form estimates of the gradient and Hessian of the value function using sample trajectories. The first algorithm requires an exact solution of the cubic regularized problem in each iteration, while the second algorithm employs an efficient gradient descent-based approximation to the cubic regularized problem. We establish convergence of our proposed algorithms to a second-order stationary point (SOSP) of the value function, which results in the avoidance of traps in the form of saddle points. In particular, the sample complexity of our algorithms to find an $\epsilon$-SOSP is $O(\epsilon^{-3.5})$, which is an improvement over the state-of-the-art sample complexity of $O(\epsilon^{-4.5})$.