Enabling Efficient, Reliable Real-World Reinforcement Learning with Approximate Physics-Based Models
This addresses the challenge of data inefficiency and unreliability in real-world reinforcement learning for robotics, representing a strong incremental improvement over existing methods.
The paper tackles the problem of inefficient and unreliable policy optimization for robot learning with real-world data by introducing a policy gradient framework that leverages approximate physics-based models, enabling precise control policies with only minutes of real-world data, as demonstrated in hardware experiments with a small car and quadruped.
We focus on developing efficient and reliable policy optimization strategies for robot learning with real-world data. In recent years, policy gradient methods have emerged as a promising paradigm for training control policies in simulation. However, these approaches often remain too data inefficient or unreliable to train on real robotic hardware. In this paper we introduce a novel policy gradient-based policy optimization framework which systematically leverages a (possibly highly simplified) first-principles model and enables learning precise control policies with limited amounts of real-world data. Our approach $1)$ uses the derivatives of the model to produce sample-efficient estimates of the policy gradient and $2)$ uses the model to design a low-level tracking controller, which is embedded in the policy class. Theoretical analysis provides insight into how the presence of this feedback controller overcomes key limitations of stand-alone policy gradient methods, while hardware experiments with a small car and quadruped demonstrate that our approach can learn precise control strategies reliably and with only minutes of real-world data.