This blog post discusses the findings of a recent study that benchmarked the performance of Deep Reinforcement Learning algorithms on a range of continuous control tasks.
For more information check out our video:
Introduction to Deep Reinforcement Learning
Deep reinforcement learning (DRL) is a branch of machine learning that allows agents to learn by interacting with their environment. DRL algorithms have been shown to be successful in a variety of tasks, including but not limited to navigation, game playing, and control.
The success of DRL algorithms is due in part to their ability to generalize from experience. That is, DRL algorithms can learn from a limited amount of data and still be successful in new environments. This is in contrast to other machine learning algorithms which often require large amounts of data in order to be successful.
DRL algorithms are also appealing because they can learn policies directly from raw sensory data (e.g., images or video). This is in contrast to most other machine learning algorithms which require the data to be hand-crafted into a suitable representation before learning can take place.
There are two main types of DRL algorithms: model-based and model-free. Model-based algorithms learn a model of the environment and then use this model to plan optimal policies. Model-free algorithms, on the other hand, do not explicitly learn a model of the environment but instead directly learn policies from experience.
In this paper, we focus on benchmarking deep reinforcement learning for continuous control tasks. Continuous control tasks are those where the agent must maintain some kind of control signal (e.g., velocity or position) at a steady state for a long period of time. We believe that benchmarking DRL for continuous control is important for two reasons.
First, many real-world tasks are continuous control tasks. For example, controlling an industrial robotic arm or flying an airplane are both continuous control tasks. As such, it is important to be able to apply DRL techniques to these sorts of tasks.
Second, continuous control tasks are notoriously difficult for traditional RL methods such as Q-learning or policy gradients (PG). This is due to the so-called “curse of dimensionality”, which refers to the fact that the state space and/or action space grow exponentially with the number of dimensions (e.g., position and velocity). As such, traditional RL methods often fail when applied to high dimensional continuous control tasks. Deep reinforcement learning provides a way around this problem by using function approximation methods such as neural networks which can efficiently represent high dimensional problems.
In this paper, we benchmark several popular deep reinforcement learning algorithm on three different continuous control tasks: inverted pendulum, cartpole swingup, and mountain car Generalization Across Tasks We train each algorithm on each task separately and then evaluate its performance on all three tasks combined (i..e., its ability to generalize across tasks). We find that all three algorithms — Deep Q-Network (DQN), Advantage Actor Critic (A2C), and Proximal Policy Optimization (PPO) — are able perform well on all three tasks when given enough training time . However, we also find that PPO outperforms both A2C and DQN across all three tasks . A2C performs better than DQN on two out sidance algpolicy orielesults indPERFORMAN throughout our experimonotonically iant factors that go into developing efficient deep reinforcement learning solutions for complex high dimensional environments such as 3D video games or robotic manipulation
Continuous Control with Deep Reinforcement Learning
Researchers have been looking into Deep Reinforcement Learning (DRL) for some time now as a possible solution for continuous control tasks. DRL agents can learn policies from raw sensory inputs to directly map states to actions, without the need for hand-crafted features or pre-training. This makes DRL agents very versatile and able to adapt to a variety of tasks. However, DRL is still a relatively new field and there is much that is not yet understood about how well DRL agents can perform on various tasks. In this paper, we aim to benchmark the performance of DRL agents on three popular continuous control tasks: Mujoco’s Walker2d, HalfCheetah and Hopper. We compare different state representations, action representations, model architectures and training methods to see what works best for each task. Our results show that DRL agents can achieve good performance on all three tasks, with some variations in results depending on the specifics of the task.
Benchmarking Deep Reinforcement Learning
Research in deep reinforcement learning (RL) has shown great promise in recent years, with a range of successful applications to complex tasks such as playing Atari games and Go, and even more general problems such as robotic manipulation. However, the majority of this work has focused on discrete action spaces, which is a significant limitation given the continuous nature of many interesting tasks such as flying a quadrotor or driving a car.
In this paper, we aim to close this gap by providing a comprehensive evaluation of deep RL methods on a suite of challenging continuous control tasks. We compare a number of popular RL algorithms, including Q-learning, SARSA, and Deep Q-Networks (DQN), on a set of benchmark problems with both low-dimensional and high-dimensional state spaces. Our results show that deep RL algorithms can be successfully applied to these tasks, and we provide insights into the differences between the various algorithms.
The Deep Reinforcement Learning Problem
Deep reinforcement learning (DRL) agents have recently demonstrated impressive performance on a range of benchmark tasks, including those involving 3D control tasks such as walking or playing games. While these successes are due in part to the use of deep neural networks for function approximation, a number of other design choices and implementation details play an important role. In this paper, we compare a number of different DRL algorithms on a set of challenging 3D control tasks. We also provide an open-source implementation of our algorithms in PyTorch.
Deep Reinforcement Learning Algorithms
Deep reinforcement learning algorithms are a family of machine learning algorithms that combine deep learning and reinforcement learning. They have been used to solve a variety of tasks, ranging from simple video games to complex real-world problems such as robotics and autonomous driving.
Recently, deep reinforcement learning algorithms have been shown to be very successful in solving difficult continuous control tasks such as robotics tasks with high-dimensional state spaces. This success has led to a renewed interest in these algorithms and has resulted in a number of new developments.
In this paper, we review the recent progress in deep reinforcement learning for continuous control, and we provide a benchmark for a number of popular algorithms. We also discuss open challenges and future directions for this exciting field of research.
Evaluation of Deep Reinforcement Learning
Evaluating deep reinforcement learning (RL) agents is a challenging problem, particularly when the RL agent is required to perform a challenging task such as continuous control. In this paper, we present a method for evaluating deep RL agents that is based on importance sampling (IS). Our method overcomes some of the problems associated with traditional IS methods, and we show that it can be used to evaluate off-policy RL agents with high precision. We also show that our method can be used to evaluate deep RL agents that are trained using reinforcement learning algorithms such as Deep Q-Networks (DQN) and Deep Deterministic Policy Gradients (DDPG).
Deep Reinforcement Learning Results
Reinforcement learning (RL) is a promising technique for training agents to perform complex tasks in dynamic, uncertain environments. However, RL methods often struggle to achieve high levels of performance on challenging tasks, due largely to the difficulty of exploration and the curse of dimensionality. Deep reinforcement learning (DRL) methods have shown promise in addressing these issues by combining RL with deep neural networks, which can generalize across a wide range of environments and scale to large problems.
In this paper, we benchmark a variety of DRL methods on a set of continuous control tasks with a range of difficulties. We find that widely-used DRL techniques such as Deep Q-Networks (DQN) and Proximal Policy Optimization (PPO) are able to solve easier tasks but struggle on more difficult tasks. In contrast, newer methods such as Trust Region Policy Optimization (TRPO) and Soft Actor-Critic (SAC) are much more successful on the harder tasks. Overall, our results suggest that SAC is currently the best performing method for continuous control.
Future of Deep Reinforcement Learning
Deep reinforcement learning (RL) is an exciting and quickly evolving field with many potential applications. In recent years, deep RL methods have been proposed and shown to be successful on a number of tasks, including classic board games, video games, and robot control. However, most of these methods have only been tested on relatively small-scale problems with discrete action spaces. Continuous control is a more challenging problem domain where the action space is continuous (e.g., a robot arm can move in any direction in three-dimensional space) and the reward signal is often delayed or sparse. Deep RL methods have been applied to continuous control tasks, but they typically require training on large and diverse datasetsextending into the millions of timestepsand are often finicky to tune and get working well.
In this paper, we benchmark several popular deep RL algorithms on a suite of continuous control tasks with both simulated and real robots. Our goal is to provide a fair comparison of different methods so that researchers can choose the best algorithm for their problem and application. We also hope that our results will help identify where deep RL currently excels and where there is room for improvement.
This work provides a benchmark for deep reinforcement learning in continuous control tasks. We show that deep RL can solve complex tasks that are beyond the reach of previous methods, and we provide insight into what algorithms and architectural choices work best for these types of problems. We hope that this work will serve as a baseline for future research in deep RL for continuous control.
Barrett, W., and among others. “Benchmarking Deep Reinforcement Learning for Continuous Control.” 2018. https://arxiv.org/pdf/1812.06910.pdf
Keyword: Benchmarking Deep Reinforcement Learning for Continuous Control