Data Collection

We developed an mcap-based (mcap.dev) data collection system that records both expert demonstrations and on-policy model rollouts.

data collection flowchart

Data Collection Flowchart

1. Structured Data & Metadata Management

  • Comprehensive Annotation: The system supports detailed annotation management, allowing for the explicit definition of user identities, task names, and specific task instructions.

  • Hierarchical Data Organization: Recorded data is structured systematically following the directory logic: {app_init_time}/{username}/{task_name}/{episode_timestamp}. Each episode package includes:

    • Raw MCAP data files.

    • Associated mcap_meta for stream indexing.

    • An extended episode_meta.json for high-level experiment metadata.

directory tree

Sample Directory Tree

  • Extensible Metadata: The system offers extensible meta-key configurations to accommodate project-specific metadata requirements.

metadata configuration

Sample Metadata Configuration

2. Data Quality & Transmission Optimization

  • Bandwidth Optimization: To mitigate bottlenecks in multi-sensor configurations, the system incorporates real-time, on-the-fly image compression and encoding.

  • Active Diagnostics: A dedicated diagnostic suite monitors frame rates in real-time. It provides instant alerts for data anomalies, such as camera frame drops or node failures, ensuring the integrity of the collected dataset.

diagnostics

Active Diagnostics

3. Visualization & Playback Interfaces

  • Real-time Visualization: We provide an integrated entrance for real-time data streaming and visualization through Foxglove, enabling live monitoring of robot states and sensor feeds.

  • Seamless Playback: A lightweight file_server is integrated into the pipeline, supporting the immediate playback and review of recorded sequences for rapid data verification.

data visualization

Real-time Visualization

data replay

Data Replay