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Data Collection for Rough Terrain Vehicle-Camera Calibration

Calibration Target:
Checkerboard is the calibration target. For small vehicles, the minimum checkerboard size is 0.6m^2. For large cars, the minimum checkerboard size is 2.4m^2. If calibrating a small car, you can print the below pdf file on a foam board at 1.0m x 0.6m. Most print shops can print this. https://drive.google.com/file/d/1mTR8HTpvROE1Pv0rmXEBVLSxs_yMDnvf?usp=sharing
For car wheels, use the Aruco markers. Click here for Aruco markers.
Data collection for vehicle-camera calibration:
  1. 1.
    We need two cameras,
    1. 1.
      A mounted camera on the car with respect to which calibration is done against the vehicle.
    2. 2.
      An external camera to take images from both left and right sides of the vehicle.
  2. 2.
    Intrinsic parameters for both mounted and external cameras before proceeding to vehicle-camera calibration. Intrinsics can be obtained from the Camera Intrinsic calibration as well.
  3. 3.
    Have a checkerboard with known horizontal corners, vertical corners, and square size.
  4. 4.
    Stick Aruco markers to the vehicle wheels to auto-detect the wheel center. Click here for Aruco markers.
Front Left:
Front Right:
Rear Left:
Rear Right:
Setup and Data collection from the Left-side of the vehicle
  1. 1.
    Place and fix the checkerboard position in the mounted camera's field of view.
  2. 2.
    Take an image from the mounted camera.
  3. 3.
    Take an image from the external camera having a front-left wheel, rear-left wheel, and checkerboard in its field of view. Move the external camera to a different location and take another image. Repeat the process for at least three iterations.
Checkerboard placed in the mounted camera's field of view
Image taken from external camera with front-left wheel, rear-left wheel and checkerboard in its field of view.
Setup and Data collection from the Right-side of the vehicle
  1. 1.
    Place and fix the checkerboard position in the mounted camera's field of view.
  2. 2.
    Take an image from the mounted camera.
  3. 3.
    Take an image from the external camera having a front-right wheel, rear-right wheel, and checkerboard in its field of view. Move the external camera to a different location and take another image. Repeat the process for at least three iterations.
Checkerboard placed in the mounted camera's field of view
Image taken from external camera with front-right wheel, rear-right wheel and checkerboard in its field of view.