Fauna Sprout: A lightweight, approachable, developer-ready humanoid robot

TL;DR

Sprout proposes a safe, accessible humanoid platform designed for long-horizon interaction in human environments. It combines a lightweight, compliant hardware design with a modular software stack, including containerized services, ROS 2-based communications, whole-body learned controllers, VR teleoperation, and on-board mapping/navigation. The key contributions span hardware safety architecture, a multi-layered software platform, sim-to-real calibration and actuator modeling, and an agent-ready toolchain for perception, reasoning, and HRI. Together, these elements aim to broaden participation in humanoid robotics by reducing deployment barriers and enabling practical, trustworthy embodied intelligence in real-world settings.

Abstract

Recent advances in learned control, large-scale simulation, and generative models have accelerated progress toward general-purpose robotic controllers, yet the field still lacks platforms suitable for safe, expressive, long-term deployment in human environments. Most existing humanoids are either closed industrial systems or academic prototypes that are difficult to deploy and operate around people, limiting progress in robotics. We introduce Sprout, a developer platform designed to address these limitations through an emphasis on safety, expressivity, and developer accessibility. Sprout adopts a lightweight form factor with compliant control, limited joint torques, and soft exteriors to support safe operation in shared human spaces. The platform integrates whole-body control, manipulation with integrated grippers, and virtual-reality-based teleoperation within a unified hardware-software stack. An expressive head further enables social interaction -- a domain that remains underexplored on most utilitarian humanoids. By lowering physical and technical barriers to deployment, Sprout expands access to capable humanoid platforms and provides a practical basis for developing embodied intelligence in real human environments.

Figures (11)

• Figure 1: Hardware overview. Key features of the Sprout robot platform from different perspectives: (A) and (B) are true-color renders, (C) and (D) are semi-transparent renders.
• Figure 2: Software overview. A conceptual sketch of the dominant processes and primary channels of communication between them. Since the communication follows a pub-sub model, additional edges may exist in practice. For example, the web interface could communicate with any service---depicted connections correspond to core capabilities. Pink-colored nodes (e.g., reasoning engine, memory, and social context) are included for illustrative purposes, but are not initially available as part of our SDK.
• Figure 3: CPU utilization. Approximate snapshot of the CPU demands of core onboard software services. In addition, some services leverage the GPU (GPU profiling not shown).
• Figure 4: Locomotion system. Supported transition structure between motor modules and motor behaviors.
• Figure 5: Teleoperation system. The communication between the VR system (green) and robot services as mediated by the core robot APIs (blue), with schematic breakouts depicting the retargeting step (pink), switching between teleoperation and autonomy (yellow), and the whole-body control layer (orange).