Skip to content

README.md

Latest commit

 

History

History
136 lines (107 loc) · 5.74 KB

README.md

File metadata and controls

136 lines (107 loc) · 5.74 KB

Visual Navigation for Aerial Autonomous Vehicles (VNAAV)

This repository contains reference python implementations for visual control of quadrotors. The primary focus is a lightweight quadrotor simulator with interchangeable controllers and sensors (including a PyBullet camera), plus the supporting code for perception and navigation.

Key capabilities include:

  • A small SE(3) quadrotor simulator with a three-rate loop (plant, sensor, controller).
  • PyBullet playback with an onboard camera and AprilTag/Aruco feature detection (PBVS controller).
  • Multiple controller modes (SE3 position, random, PBVS, smoothed PBVS) and configurable trajectories.
  • Reusable scene/camera helpers for swapping drone visuals and environments.
PyBullet Editable Worlds Drone Cameras

Requirements

Core requirements (headless simulation):

  • Python 3.x
  • numpy
  • matplotlib (for plotting/animation)

PyBullet playback:

  • pybullet

PBVS (AprilTag/Aruco) controller:

  • opencv-contrib-python (for cv2.aruco)

Usage examples

Headless simulation (matplotlib only):

python -m py_labs.quadrotor_sim.run_simulation --duration 20 --controller-rate 200 --sim-dt 0.002

SE(3) controller with PyBullet playback:

python -m py_labs.quadrotor_sim.run_bullet_simulation --controller se3 --duration 20

Random controller for quick stress testing:

python -m py_labs.quadrotor_sim.run_bullet_simulation --controller random --duration 10

PBVS controller (AprilTag/Aruco) with camera observations:

python -m py_labs.quadrotor_sim.run_bullet_simulation --controller pbvs --duration 20

Smoothed PBVS controller (EMA on derived velocities):

python -m py_labs.quadrotor_sim.run_bullet_simulation --controller smoothed-pbvs --duration 20

Use the A2RL drone URDF and physical parameters:

python -m py_labs.quadrotor_sim.run_bullet_simulation --controller se3 --a2rl

Hover trajectory with a fixed yaw:

python -m py_labs.quadrotor_sim.run_bullet_simulation --trajectory hover --hover-yaw 0.5

Simulator architecture

At a high level the system is wired as:

TrajectoryCommand -> Controller -> ControlInput -> Plant (QuadrotorPlant)
                                        |                 |
                                        v                 v
                               Sensor/Scene/Camera      SimulationLog

Key components:

  • Plant: py_labs/quadrotor_sim/plant.py integrates rigid-body quadrotor dynamics.
  • Controller: py_labs/quadrotor_sim/controller.py provides SE3 position control, random control, PBVS (vision-based) control, and smoothed PBVS control.
  • Simulator: py_labs/quadrotor_sim/simulator.py runs independent plant, sensor, and controller rates.
  • Scene/Camera: py_labs/quadrotor_sim/scene.py owns the PyBullet scene, camera pose, and rendering. The camera uses a render frame for PyBullet and converts to OpenCV conventions for pose estimation.

Command line reference

Headless simulation (run_simulation.py)

python -m py_labs.quadrotor_sim.run_simulation [options]
Option Default Description
--duration 20.0 Total simulation time (seconds).
--radius 1.0 Circle radius for circular trajectory.
--height 1.2 Circle altitude for circular trajectory.
--angular-rate 0.4 Angular rate (rad/s) for circular trajectory.
--controller-rate 200.0 Controller update rate in Hz.
--sim-dt 0.002 Plant integration time step (seconds).
--trajectory circle Trajectory type: circle or hover.
--hover-x 0.0 Hover x position (meters).
--hover-y 0.0 Hover y position (meters).
--hover-height 3.0 Hover z position (meters).
--hover-yaw 0.0 Hover yaw (radians).

PyBullet playback (run_bullet_simulation.py)

python -m py_labs.quadrotor_sim.run_bullet_simulation [options]
Option Default Description
--duration 20.0 Total simulation time (seconds).
--radius 1.0 Circle radius for circular trajectory.
--height 1.2 Circle altitude for circular trajectory.
--angular-rate 0.4 Angular rate (rad/s) for circular trajectory.
--controller-rate 200.0 Controller update rate in Hz.
--sim-dt 0.002 Plant integration time step (seconds).
--noise false Use a noisy state sensor.
--trajectory circle Trajectory type: circle or hover.
--hover-x 0.0 Hover x position (meters).
--hover-y 0.0 Hover y position (meters).
--hover-height 3.0 Hover z position (meters).
--hover-yaw None Hover yaw (radians). Defaults to plant initial yaw.
--playback-stride 1 Skip this many frames during playback.
--max-features 200 Max features per frame (feature extractor).
--feature-min-distance 5.0 Minimum pixel spacing between detected features.
--controller se3 Controller choice: se3, random, pbvs, smoothed-pbvs.
--a2rl false Use A2RL drone URDF and physical parameters.
--aruco_scene false Reserved flag for ArUco scene generation (not wired in the entrypoint).
--basic_drone false Force basic drone visual (default if --a2rl not set).

References

The plant model and the SE(3) controller are from MIT's VNAV course.