This page provides definitions for codebase-specific terms, abbreviations, and domain concepts used throughout the openpilot repository. It serves as a technical reference for onboarding engineers to understand the mapping between high-level concepts and their implementations in code.
| Term | Definition | Key Code Entities |
|---|---|---|
| AGNOS | The custom Ubuntu-based operating system designed for comma hardware. | launch_env.sh19-20 RELEASES.md117 |
| CarParams (CP) | A Cap'n Proto struct containing static vehicle-specific parameters (mass, steer ratio, safety configs). | openpilot/selfdrive/modeld/modeld.py12 |
| CarState (CS) | A Cap'n Proto struct containing the real-time state of the car (speed, steering angle, button presses). | openpilot/selfdrive/modeld/modeld.py9 |
| Fingerprinting | The process of identifying the specific car make/model based on CAN bus messages or ECU firmware versions. | RELEASES.md103-104 RELEASES.md119 |
| Panda | The custom interface hardware/firmware that handles safety-critical CAN communication. | README.md82-85 docs/how-to/connect-to-comma.md7-8 |
| vEgo | The current vehicle speed as estimated by openpilot. | openpilot/selfdrive/modeld/modeld.py38-53 |
| vCruise | The target cruise control speed set by the user or the system. | RELEASES.md101 |
Sources: openpilot/selfdrive/modeld/modeld.py37-62 RELEASES.md100-120 README.md80-90
openpilot uses a distributed architecture where independent processes communicate over msgq (IPC) using cereal (Cap'n Proto) messages.
modeld: Runs the driving vision and policy neural networks. It utilizes tinygrad for tensor operations and JIT compilation of models.
dmonitoringmodeld: Specifically handles the driver monitoring model to ensure driver attentiveness.
camerad: Handles raw camera frame acquisition and ISP processing.
ui: The user interface process that renders the road view, alerts, and settings.
"Data flow between vision and control daemons"
Sources: openpilot/selfdrive/modeld/modeld.py10-17 launch_env.sh9-16 RELEASES.md82-85
tinygrad used to accelerate model execution on the device.
Sources: openpilot/selfdrive/modeld/modeld.py78-100 openpilot/selfdrive/modeld/compile_modeld.py117-135
A unified CLI tool for managing the openpilot development environment, including installation, setup, and dependency checks.
op setup: Installs submodules and dependencies. tools/op.sh195-222op install: Installs the op command system-wide. tools/op.sh22-33A tool used to replay recorded driving logs (routes) to simulate a car environment on a PC for UI or algorithm development.
"Mapping CLI Commands to Code Actions"
Sources: tools/op.sh195-222 tools/setup.sh122-136
Sources: README.md53-63 RELEASES.md50-60 openpilot/selfdrive/modeld/modeld.py11-17