Reinforcement Learning
Berkeley startup to train robots like puppets
Robots today must be programmed by writing computer code, but imagine donning a VR headset and virtually guiding a robot through a task, like you would move the arms of a puppet, and then letting the robot take it from there. That's the vision of Pieter Abbeel, a professor of electrical engineering and computer science at the University of California, Berkeley, and his students, Peter Chen, Rocky Duan and Tianhao Zhang, who have launched a startup, Embodied Intelligence Inc., to use the latest techniques of deep reinforcement learning and artificial intelligence to make industrial robots easily teachable. "Right now, if you want to set up a robot, you program that robot to do what you want it to do, which takes a lot of time and a lot of expertise," said Abbeel, who is currently on leave to turn his vision into reality. "With our advances in machine learning, we can write a piece of software once -- machine learning code that enables the robot to learn -- and then when the robot needs to be equipped with a new skill, we simply provide new data." The "data" is training, much like you'd train a human worker, though with the added dimension of virtual reality.
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Building on the founders' pioneering research in deep imitation learning, deep reinforcement learning and meta-learning, Embodied Intelligence is developing AI software (aka robot brains) that can be loaded onto any existing robots. While traditional programming of robots requires writing code, a time-consuming endeavor even for robotics experts, Embodied Intelligence software will empower anyone to program a robot by simply donning a VR headset and guiding a robot through a task. These human demonstrations train deep neural nets, which are further tuned through the use of reinforcement learning, resulting in robots that can be easily taught a wide range of skills in areas where existing solutions break down. Complicated tasks like the manipulation of deformable objects such as wires, fabrics, linens, apparel, fluid-bags, and food; picking parts and order items out of cluttered, unstructured bins; completing assemblies where hard automation struggles due to variability in parts, configurations, and individualization of orders, are all candidates to benefit from Embodied Intelligence's work.
Deep reinforcement learning: where to start – freeCodeCamp
More than 200 million people watched as reinforcement learning (RL) took to the world stage. A few years earlier, DeepMind had made waves with a bot that could play Atari games. The company was soon acquired by Google. Many researchers believe that RL is our best shot at creating artificial general intelligence. It is an exciting field, with many unsolved challenges and huge potential.
[D] What do you feel is currently undervalued / underappreciated in the field of machine learning? • r/MachineLearning
Good reinforcement learning and other'reasoning' benchmarks to measure progress, some set of increasingly harder tasks that can measurably show the different strengths of various models. My thoughts are that it wasn't just the data, but everything around image-net that really pushed the field forward, the yearly competition, the talks and progress graphs the anticipation and excitement to see how far the teams pushed the limit this time. Reinforcement learning still needs its'image-net moment', ideally some annual competition that can gain traction over time, have the big teams invest resource to push the limits. The field lends itself well to simply adding more complex tasks as the models get stronger and stronger. I merely answered this question as in'what would I as an outsider like to see', so feel free to disregard', but I think there is something in the human nature about competition which drives progress.
Learning in Brains and Machines (3): Synergistic and Modular Action
Action synergies in the brain are paralleled by macro-actions and options in machines. In both brains and machines, these tools enable fast learning, strong generalisation and flexible action. But most importantly, for we who seek a deeper understanding of the brain, and human and machine intelligence, this has illuminated the principles of modularity an abstraction--an invaluable principle of biological and computational learning.
Reinforcement Learning of Speech Recognition System Based on Policy Gradient and Hypothesis Selection
Kato, Taku, Shinozaki, Takahiro
Speech recognition systems have achieved high recognition performance for several tasks. However, the performance of such systems is dependent on the tremendously costly development work of preparing vast amounts of task-matched transcribed speech data for supervised training. The key problem here is the cost of transcribing speech data. The cost is repeatedly required to support new languages and new tasks. Assuming broad network services for transcribing speech data for many users, a system would become more self-sufficient and more useful if it possessed the ability to learn from very light feedback from the users without annoying them. In this paper, we propose a general reinforcement learning framework for speech recognition systems based on the policy gradient method. As a particular instance of the framework, we also propose a hypothesis selection-based reinforcement learning method. The proposed framework provides a new view for several existing training and adaptation methods. The experimental results show that the proposed method improves the recognition performance compared to unsupervised adaptation.
AI Startup Embodied Intelligence Wants Robots to Learn From Humans in Virtual Reality
We are building technology that enables existing robot hardware to handle a much wider range of tasks where existing solutions break down, for example, bin picking of complex shapes, kitting, assembly, depalletizing of irregular stacks, and manipulation of deformable objects such as wires, cables, fabrics, linens, fluid-bags, and food. To equip existing robots with these skills, our software builds on the latest advances in deep reinforcement learning, deep imitation learning, and few-shot learning, to all of which the founding team has made significant contributions. The result isn't just a new set of skills in the robot repertoire, but teachable robots, that can be deployed for new tasks on short turn-around. The background here will be familiar to anyone who has followed Abbeel's research at UC Berkeley's Robot Learning Lab (RLL).
Reinforcement Learning under Model Mismatch
Roy, Aurko, Xu, Huan, Pokutta, Sebastian
Reinforcement learning is concerned with learning a good policy for sequential decision making problems modeled as a Markov Decision Process (MDP), via interacting with the environment [22, 20]. In this work we address the problem of reinforcement learning from a misspecified model. As a motivating example, consider the scenario where the problem of interest is not directly accessible, but instead the agent can interact with a simulator whose dynamics is reasonably close to the true problem. Another plausible application is when the parameters of the model may evolve over time but can still be reasonably approximated by an MDP. To address this problem we use the framework of robust MDPs which was proposed by [2, 17, 13] to solve the planning problem under model misspecification. The robust MDP framework considers a class of models and finds the robust optimal policy which is a policy that performs best under the worst model. It was shown by [2, 17, 13] that the robust optimal policy satisfies the robust Bellman equation which naturally leads to exact dynamic programming algorithms to find an optimal policy. However, this approach is model dependent and does not immediately generalize to the model-free case where the parameters of the model are unknown. Essentially, reinforcement learning is a model-free framework to solve the Bellman equation using samples.
Boltzmann Exploration Done Right
Cesa-Bianchi, Nicolò, Gentile, Claudio, Lugosi, Gábor, Neu, Gergely
Boltzmann exploration is a classic strategy for sequential decision-making under uncertainty, and is one of the most standard tools in Reinforcement Learning (RL). Despite its widespread use, there is virtually no theoretical understanding about the limitations or the actual benefits of this exploration scheme. Does it drive exploration in a meaningful way? Is it prone to misidentifying the optimal actions or spending too much time exploring the suboptimal ones? What is the right tuning for the learning rate? In this paper, we address several of these questions in the classic setup of stochastic multi-armed bandits. One of our main results is showing that the Boltzmann exploration strategy with any monotone learning-rate sequence will induce suboptimal behavior. As a remedy, we offer a simple non-monotone schedule that guarantees near-optimal performance, albeit only when given prior access to key problem parameters that are typically not available in practical situations (like the time horizon $T$ and the suboptimality gap $\Delta$). More importantly, we propose a novel variant that uses different learning rates for different arms, and achieves a distribution-dependent regret bound of order $\frac{K\log^2 T}{\Delta}$ and a distribution-independent bound of order $\sqrt{KT}\log K$ without requiring such prior knowledge. To demonstrate the flexibility of our technique, we also propose a variant that guarantees the same performance bounds even if the rewards are heavy-tailed.