Learning Navigation Skills for Legged Robots with Learned Robot Embeddings

TL;DR

This paper develops hierarchical, dynamics-aware navigation policies for legged robots, enabling efficient transfer from simulation to real-world robots by learning robot-specific embeddings for quick adaptation.

Contribution

It introduces a method for learning robot-specific embeddings that facilitate transfer of navigation policies across different legged robots, accounting for their unique dynamics.

Findings

Policies generalize to unseen robots in simulation.

Successful sim-to-real transfer demonstrated on real-world quadruped.

Embeddings enable quick adaptation to new robots.

Abstract

Recent work has shown results on learning navigation policies for idealized cylinder agents in simulation and transferring them to real wheeled robots. Deploying such navigation policies on legged robots can be challenging due to their complex dynamics, and the large dynamical difference between cylinder agents and legged systems. In this work, we learn hierarchical navigation policies that account for the low-level dynamics of legged robots, such as maximum speed, slipping, contacts, and learn to successfully navigate cluttered indoor environments. To enable transfer of policies learned in simulation to new legged robots and hardware, we learn dynamics-aware navigation policies across multiple robots with robot-specific embeddings. The learned embedding is optimized on new robots, while the rest of the policy is kept fixed, allowing for quick adaptation. We train our policies across three legged robots in simulation - 2 quadrupeds (A1, AlienGo) and a hexapod (Daisy). At test time, we study the performance of our learned policy on two new legged robots in simulation (Laikago, 4-legged Daisy), and one real-world quadrupedal robot (A1). Our experiments show that our learned policy can sample-efficiently generalize to previously unseen robots, and enable sim-to-real transfer of navigation policies for legged robots.