VAE-Loco: Versatile Quadruped Locomotion by Learning a Disentangled Gait Representation

TL;DR

This paper introduces VAE-Loco, a generative model that learns a disentangled gait representation for quadruped robots, enabling continuous, online variation of trot styles and improved robustness to disturbances.

Contribution

It presents a novel latent space learning approach that allows real-time, continuous gait modulation and disturbance mitigation for quadruped locomotion.

Findings

Achieves continuous blend of trot styles during robot operation

Demonstrates robustness and reactivity to external perturbations

Validates approach on two versions of real quadruped robots

Abstract

Quadruped locomotion is rapidly maturing to a degree where robots are able to realise highly dynamic manoeuvres. However, current planners are unable to vary key gait parameters of the in-swing feet midair. In this work we address this limitation and show that it is pivotal in increasing controller robustness by learning a latent space capturing the key stance phases constituting a particular gait. This is achieved via a generative model trained on a single trot style, which encourages disentanglement such that application of a drive signal to a single dimension of the latent state induces holistic plans synthesising a continuous variety of trot styles. We demonstrate that specific properties of the drive signal map directly to gait parameters such as cadence, footstep height and full stance duration. Due to the nature of our approach these synthesised gaits are continuously variable online during robot operation. The use of a generative model facilitates the detection and mitigation of disturbances to provide a versatile and robust planning framework. We evaluate our approach on two versions of the real ANYmal quadruped robots and demonstrate that our method achieves a continuous blend of dynamic trot styles whilst being robust and reactive to external perturbations.