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Lander Auto Align

Context: In the ES mission we must align the rover with a mock lander. This is best explained visually so ask a lead for URC film.

Problem: Manually aligning with a face on the lander is difficult.

Solution: Use the ZED to detect the closest face on the lander. Run a control loop to align the rover heading with the normal of that face.

  • Downsample the point cloud so it is faster to process
  • Filter out all points which have normal z-components far away from zero, this will remove the ground
  • Filter out any other outliers to try and get only points on the lander face
  • Run principle component analysis (PCA) algorithm on remaining points to find directions of variation (eigenvectors)
  • Vector closest to the 0 vector should be the plane
  • Start with finding rover angle to plane and then move on to some sort of control loop

Interface (subject to change): Use a action server to run a closed loop control algorithm, implementing a nonlinear feedforward plus feedback control law.

Completed:

  1. PCA algorithm

To be Done:

  1. Calculate angle
  2. Move to lander