Complete Calibration and Detection Procedure

Step 1: Setup Configuration Files

1. Create arena_config.yml with fixed marker positions:

   markers:
     - id: 1
       position: [0, 0]
     - id: 2
       position: [0, 1]
     - id: 3
       position: [0, 2]
   

2. Create arena_transformation.yml with an initial transformation matrix (example identity matrix):

   transformation_matrix: !!opencv-matrix
      rows: 3
      cols: 3
      dt: d
      data: [1, 0, 0, 0, 1, 0, 0, 0, 1]
   

Step 2: Calibrate the Camera

1. Run the calibration_webcam node to capture frames and calibrate the camera:

   rosrun your_package calibration_webcam
   

2. Follow the on-screen instructions to capture at least 10 frames of the chessboard pattern from different angles and positions.

3. The calibration parameters will be saved to camera_parameters.yml.

Step 3: Calibrate the Arena

1. Run the arena_calibration node to detect ArUco markers and calibrate the arena:

   rosrun your_package arena_calibration
   

2. The detected marker positions and transformation matrix will be saved to arena_config.yml and arena_transformation.yml respectively.

Step 4: Run the Main Node

1. Run the aruco_detector node to detect ArUco markers and display their positions in the arena:

   rosrun your_package aruco_detector
   

2. The node will process frames from the camera, detect ArUco markers, and display their positions in the arena frame.

Additional Information

Dependencies

Ensure you have the following dependencies installed:

• ROS
• OpenCV
• yaml-cpp

Building the Package

1. Navigate to your catkin workspace:

   cd ~/catkin_ws
   

2. Build the package:

   catkin build test
   

3. Source the workspace:

   source devel/setup.bash
   

Running the Nodes

1. Start the ROS master node:

   roscore
   

2. In a new terminal, run the desired node as described in the steps above.

Troubleshooting

• If the camera is not detected, ensure it is properly connected and recognized by the system.
• If not enough markers are detected, try adjusting the lighting conditions or the camera position.
• Ensure all configuration files (camera_parameters.yml, arena_config.yml, arena_transformation.yml) are correctly formatted and located in the appropriate directory.

Example Configuration Files

camera_parameters.yml:

camera_matrix: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [fx, 0, cx, 0, fy, cy, 0, 0, 1]
distortion_coefficients: !!opencv-matrix
   rows: 1
   cols: 5
   dt: d
   data: [k1, k2, p1, p2, k3]

arena_config.yml:

markers:
  - id: 1
    position: [0, 0]
  - id: 2
    position: [0, 1]
  - id: 3
    position: [0, 2]

arena_transformation.yml:

transformation_matrix: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [1, 0, 0, 0, 1, 0, 0, 0, 1]